Sample records for huge electro-osmotic slip

  1. Equilibrium Electro-osmotic Instability

    CERN Document Server

    Rubinstein, Isaak


    Since its prediction fifteen years ago, electro-osmotic instability has been attributed to non-equilibrium electro-osmosis related to the extended space charge which develops at the limiting current in the course of concentration polarization at a charge-selective interface. This attribution had a double basis. Firstly, it has been recognized that equilibrium electro-osmosis cannot yield instability for a perfectly charge-selective solid. Secondly, it has been shown that non-equilibrium electro-osmosis can. First theoretical studies in which electro-osmotic instability was predicted and analyzed employed the assumption of perfect charge-selectivity for the sake of simplicity and so did the subsequent numerical studies of various time-dependent and nonlinear features of electro-osmotic instability. In this letter, we show that relaxing the assumption of perfect charge-selectivity (tantamount to fixing the electrochemical potential in the solid) allows for equilibrium electro-osmotic instability. Moreover, we s...

  2. Analytical and numerical study of the electro-osmotic annular flow of viscoelastic fluids. (United States)

    Ferrás, L L; Afonso, A M; Alves, M A; Nóbrega, J M; Pinho, F T


    In this work we present semi-analytical solutions for the electro-osmotic annular flow of viscoelastic fluids modeled by the Linear and Exponential PTT models. The viscoelastic fluid flows in the axial direction between two concentric cylinders under the combined influences of electrokinetic and pressure forcings. The analysis invokes the Debye-Hückel approximation and includes the limit case of pure electro-osmotic flow. The solution is valid for both no slip and slip velocity at the walls and the chosen slip boundary condition is the linear Navier slip velocity model. The combined effects of fluid rheology, electro-osmotic and pressure gradient forcings on the fluid velocity distribution are also discussed.

  3. Electro-osmotic pumping of sodium chloride solutions

    CSIR Research Space (South Africa)

    Schoeman, JJ


    Full Text Available Electro-osmotic pumping (EOP) theory and its characteristics (transport numbers, brine concentration, current density, current efficiency, electro-osmotic coefficients, etc.) of Selemion AMV and CMV ion-exchange membranes were studied. The brine...

  4. Ionic Origin of Electro-osmotic Flow Hysteresis (United States)

    Lim, Chun Yee; Lim, An Eng; Lam, Yee Cheong


    Electro-osmotic flow, the driving of fluid at nano- or micro- scales with electric field, has found numerous applications, ranging from pumping to chemical and biomedical analyses in micro-devices. Electro-osmotic flow exhibits a puzzling hysteretic behavior when two fluids with different concentrations displace one another. The flow rate is faster when a higher concentration solution displaces a lower concentration one as compared to the flow in the reverse direction. Although electro-osmotic flow is a surface phenomenon, rather counter intuitively we demonstrate that electro-osmotic flow hysteresis originates from the accumulation or depletion of pH-governing minority ions in the bulk of the fluid, due to the imbalance of electric-field-induced ion flux. The pH and flow velocity are changed, depending on the flow direction. The understanding of electro-osmotic flow hysteresis is critical for accurate fluid flow control in microfluidic devices, and maintaining of constant pH in chemical and biological systems under an electric field.

  5. Electro-osmotic mobility of non-Newtonian fluids. (United States)

    Zhao, Cunlu; Yang, Chun


    Electrokinetically driven microfluidic devices are usually used to analyze and process biofluids which can be classified as non-Newtonian fluids. Conventional electrokinetic theories resulting from Newtonian hydrodynamics then fail to describe the behaviors of these fluids. In this study, a theoretical analysis of electro-osmotic mobility of non-Newtonian fluids is reported. The general Cauchy momentum equation is simplified by incorporation of the Gouy-Chapman solution to the Poisson-Boltzmann equation and the Carreau fluid constitutive model. Then a nonlinear ordinary differential equation governing the electro-osmotic velocity of Carreau fluids is obtained and solved numerically. The effects of the Weissenberg number (Wi), the surface zeta potential (ψ¯s), the power-law exponent(n), and the transitional parameter (β) on electro-osmotic mobility are examined. It is shown that the results presented in this study for the electro-osmotic mobility of Carreau fluids are quite general so that the electro-osmotic mobility for the Newtonian fluids and the power-law fluids can be obtained as two limiting cases.

  6. Electro-osmotic transport in wet processing of textiles (United States)

    Cooper, John F.


    Electro-osmotic (or electrokinetic) transport is used to efficiently force a solution (or water) through the interior of the fibers or yarns of textile materials for wet processing of textiles. The textile material is passed between electrodes that apply an electric field across the fabric. Used alone or in parallel with conventional hydraulic washing (forced convection), electro-osmotic transport greatly reduces the amount of water used in wet processing. The amount of water required to achieve a fixed level of rinsing of tint can be reduced, for example, to 1-5 lbs water per pound of fabric from an industry benchmark of 20 lbs water/lb fabric.

  7. Electro-osmotically controllable multi-flow microreactor

    NARCIS (Netherlands)

    Kohlheyer, Dietrich; Besselink, Geert A.J.; Lammertink, Rob G.H.; Schlautmann, Stefan; Unnikrishnan, Sandeep; Schasfoort, Richard B.M.


    An adjustable diffusion-based microfluidic reactor is presented here, which is based on electro-osmotic guiding of reagent samples. The device consists of a laminar flow chamber with two separate reagent inlets. The position and the width of the two sample streams in the flow chamber can be controll

  8. Modulating Electro-osmotic Flow with Polymer Coatings (United States)

    Hickey, Owen A.

    Micro- and nano-fluidic devices represent an exciting field with a wide range of possible applications. These devices, typically made of either silica or glass, ionize when placed in contact with water. Upon the application of an electric field parallel to the wall, a flow is produced by the charged walls called the electro-osmotic flow (EOF). Since electric fields are so often used as the driving force in these devices, EOF is an extremely common phenomenon. For this reason it is highly desirable to be able to control EOF in order to optimize the functioning of these devices. One method which is quite common experimentally is the modification of the surface using polymer coatings. These coatings can be either adsorbed or grafted, and charged or neutral. The first part of this thesis looks at the role of neutral adsorbed polymer coatings for the modulation of EOF. Specifically our simulation results show that for adsorbed coatings made from a dilute polymer solution the strongest quenching of EOF is found for an adsorption strength at the phase transition for adsorption of the polymers. Further evidence is presented that shows that by using a high density of polymer solution and a polymer which has a strong attraction to the surface a very thick polymer layer can be created. Next the case of charged grafted polymer coatings is examined. The variation of the EOF with respect to several key parameters which characterize the polymer coating is investigated and compared to theory. The prediction that the electrophoretic velocity of the polymers is the same as the EOF generated by a coating made up of the same polymers is found to be false though the two values are quite close. The last section presents results which show how hydrodynamic interactions in charged polymer systems can be modeled mesoscopically without the use of explicit charges by forcing a slip between monomers and the surrounding fluid. This model is validated by simulating some surprising predictions

  9. Intravesical electro-osmotic administration of mitomycin C. (United States)

    Di Stasi, Savino M; Verri, Cristian; Celestino, Francesco; De Carlo, Francesco; Pagliarulo, Vincenzo


    Bladder cancer is very common and most cases are diagnosed as nonmuscle invasive disease, which is characterized by its propensity to recur and progress. Intravesical therapy is used to delay recurrence and progression, while cystectomy is reserved for patients who are refractory to transurethral resection and intravesical therapy. There is an increasing interest in methods to enhance the delivery of intravesical chemotherapeutic agents to improve efficacy. In vitro and in vivo studies demonstrated that electro-osmosis of mitomycin C (MMC) is more effective in delivering this drug into the urothelium, lamina propria, and superficial muscle layers of the bladder wall than is passive transport. Higher MMC tissue concentrations might have a clinical impact in the treatment of nonmuscle invasive bladder cancer (NMIBC). In randomized trials, intravesical electro-osmotic MMC was associated with superior response rate in high-risk NMIBC cancer, compared with passive diffusion MMC transport. New strategies such as intravesical Bacillus Calmette-Guerin (BCG) combined with electro-osmotic MMC as well as intravesical pre-operative electro-osmotic MMC provided promising results in terms of higher remission rates and longer remission times.Device-assisted intravesical chemotherapy may be a useful ancillary procedure in the treatment of NMIBC. Its evaluation must be planned with respect to the technical functioning of equipment and their use for a clear purpose to avoid the financial and human costs associated with incorrect therapies.

  10. AC electro-osmotic mixing induced by non-contact external electrodes. (United States)

    Wang, Shau-Chun; Chen, Hsiao-Ping; Lee, Chia-Yu; Yu, Chun-Ching; Chang, Hsueh-Chia


    We demonstrate efficient mixing in a micro-fluidic reservoir smaller than 10 microL using ac electro-osmosis driven by field-induced polarization. Our mixing device, of that electrodes are outside of the mixing unit, consists of three circular reservoirs (3mm in diameter) connected by a 1 mm x 1 mm channel. Unlike dc electro-osmosis, whose polarization is from charged substrate functional groups, this new mechanism uses the external field to capacitively charge the surface and the surface capacitance becomes the key factor in the electrokinetic mobility. The charging and mixing are enhanced at tailor-designed channel corners by exploiting the high normal fields at geometric singularities. The induced surface dielectric polarization and the resulting electric counter-ion double layer produce an effective Zeta potential in excess of 1 V, over one order of magnitude larger than the channel Zeta potential. The resulting ac electro-osmotic slip velocity scales quadratically with respect to the applied field, in contrast to the linear scaling of dc electro-osmosis and at 1cm/s and larger, exceeds the classical dc values by two orders of magnitude. The polarization is non-uniform at the corners due to field leakage to the dielectric substrate and the inhomogeneous slip velocity produces intense mixing vortices that effectively homogenize solutes in 30s in a 3mm reservoir, in contrast to hour-long mixing by pure diffusion.

  11. Numerical analysis of dynamic electro-osmotic flows of non-Newtonian fluids in rectangular microchannels

    CERN Document Server

    Zhao, Cunlu


    Numerical analyses of transient electro-osmosis of a typical non-Newtonian liquid induced by DC and AC electric fields in a rectangular microchannel are conducted in the framework of continuum fluid mechanics. The famous power-law constitutive model is used to express the fluid dynamic viscosity in terms of the velocity gradient. Transient start-up characteristics of electro-osmotic power-law liquid flow in rectangular microchannels are simulated by using finite element method. Under a DC electric field, it is found out and the fluid is more inert to the external electric field and the steady-state velocity profile becomes more plug-like with decrease of the flow behavior index of the power-law liquids. The numerical calculations also confirm the validity of the generalized Smoluchowski slip velocity which can serve as the counterpart for the classic Smoluchowski slip velocity when dealing with electrokinetic flow of non-Newtonian power-law fluids. Under AC electric fields, the fluid is more obviously acceler...

  12. Topology and shape optimization of induced-charge electro-osmotic micropumps

    DEFF Research Database (Denmark)

    Gregersen, Misha Marie; Okkels, Fridolin; Bazant, M. Z.;


    For a dielectric solid surrounded by an electrolyte and positioned inside an externally biased parallel-plate capacitor, we study numerically how the resulting induced-charge electro-osmotic (ICEO) flow depends on the topology and shape of the dielectric solid. In particular, we extend existing...

  13. Feasibility of electro-osmotic belt filter dewatering technology at pilot scale

    CSIR Research Space (South Africa)

    Snyman, HG


    Full Text Available -effective dewatering technologies, electro-osmotic belt filtering was developed by Smollen and Kafaar in 1995. The mechanical equipment resembles a belt filter press but the belts are stainless steel, woven belts, which act as the electrodes. In this study...

  14. Experimental Verification of Overlimiting Current by Surface Conduction and Electro-osmotic Flow in Microchannels

    CERN Document Server

    Nam, Sungmin; Heo, Joonseong; Lim, Geunbae; Bazant, Martin Z; Sung, Gunyong; Kim, Sung Jae


    Possible mechanisms of overlimiting current in unsupported electrolytes, exceeding diffusion limitation, have been intensely studied for their fundamental significance and applications to desalination, separations, sensing, and energy storage. In bulk membrane systems, the primary physical mechanism is electro-convection, driven by electro-osmotic instability on the membrane surface. It has recently been predicted that confinement by charged surfaces in microchannels or porous media favors two new mechanisms, electro-osmotic flow (EOF) and surface conduction (SC), driven by large electric fields in the depleted region acting on the electric double layers on the sidewalls. Here, we provide the first direct evidence for the transition from SC to EOF above a critical channel height, using in situ particle tracking and current-voltage measurements in a micro/nanofluidic device. The dependence of the over-limiting conductance on channel depth (d) is consistent with theoretical predictions, scaling as d^-1 for SC a...

  15. Particle Dynamics and Rapid Trapping in Electro-Osmotic Flow Around a Sharp Microchannel Corner

    CERN Document Server

    Zehavi, Matan


    We study here the curious particle dynamics resulting from electro-osmotic flow around a microchannel junction corner whose dielectric walls are weakly polarizable. The hydrodynamic velocity field is obtained via superposition of a linear irrotational term associated with the equilibrium zeta potentials of both the microchannel and particle surfaces and the non-linear induced-charge electro-osmotic flow which originates from the interaction of the externally applied electric field on the charge cloud it induces at the solid-liquid interface. The particle dynamics are analyzed by considering dielectrophoretic forces via the addition of a mobility term to the flow field in the limit of Stokes drag law. The former, non-divergence free term is responsible for migration of particles towards the sharp microchannel junction corner, where they can potentially accumulate. Experimental observations of particle trapping for various applied electric fields and microparticle size are rationalized in terms of the growing r...

  16. Effect of Electro-Osmotic Flow on Energy Conversion on Superhydrophobic Surfaces

    CERN Document Server

    Seshadri, Gowrishankar


    It has been suggested that superhydrophobic surfaces, due to the presence of a no-shear zone, can greatly enhance transport of surface charges, leading to a considerable increase in the streaming potential. This could find potential use in micro-energy harvesting devices. In this paper, we show using analytical and numerical methods, that when a streaming potential is generated in such superhydrophobic geometries, the reverse electro-osmotic flow and hence current generated by this, is significant. A decrease in streaming potential compared to what was earlier predicted is expected. We also show that, due to the electro-osmotic streaming-current, a saturation in both the power extracted and efficiency of energy conversion is achieved in such systems for large values of the free surface charge densities. Nevertheless, under realistic conditions, such microstructured devices with superhydrophobic surfaces have the potential to even reach energy conversion efficiencies only achieved in nanostructured devices so ...

  17. Microfluidic analogy of the wheatstone bridge for systematic investigations of electro-osmotic flows. (United States)

    Plecis, Adrien; Chen, Yong


    A microfluidic analogy of the electric Wheatstone Bridge has been developed for electrokinetic study of miscellaneous liquid-solid interfaces. By using an optimized glass-PDMS-glass device technology, microfluidic channels with well-controlled surface properties can be fabricated, forming an "H" shaped fluidic network. After solving a set of linear equations, the electro-osmotic flow rate in the center channel can be deduced from indirect measurement of flow rates in the lateral channels. Experimentally, we demonstrate that the electro-osmotic mobility can be monitored every 30 s with accuracy better than 3% for a large dynamic range of electric fields. The results obtained with a borosilicate glass (D-263) and several standard biological buffers are also shown to illustrate the capability of this high throughput method.

  18. Controlled assembly of single colloidal crystals using electro-osmotic micro-pumps


    Niu, Ran; Oğuz, Erdal C.; Müller, Hannah; Reinmüller, Alexander; Botin, Denis; Löwen, Hartmut; Palberg, Thomas


    We assemble charged colloidal spheres at deliberately chosen locations on a charged unstructured glass substrate utilizing ion exchange based electro-osmotic micro-pumps. Using microscopy, a simple scaling theory and Brownian Dynamics simulations, we systematically explore the control parameters of crystal assembly and the mechanisms through which they depend on the experimental boundary conditions. We demonstrate that crystal quality depends crucially on the assembly distance of the colloids...

  19. Topology and shape optimization of induced-charge electro-osmotic micropumps

    Energy Technology Data Exchange (ETDEWEB)

    Gregersen, M M; Okkels, F; Bruus, H [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, DK-2800 Kongens Lyngby (Denmark); Bazant, M Z [Departments of Chemical Engineering and Mathematics, MIT, Cambridge, MA 02139 (United States)], E-mail:


    For a dielectric solid surrounded by an electrolyte and positioned inside an externally biased parallel-plate capacitor, we study numerically how the resulting induced-charge electro-osmotic (ICEO) flow depends on the topology and shape of the dielectric solid. In particular, we extend existing conventional electrokinetic models with an artificial design field to describe the transition from the liquid electrolyte to the solid dielectric. Using this design field, we have succeeded in applying the method of topology optimization to find system geometries with non-trivial topologies that maximize the net induced electro-osmotic flow rate through the electrolytic capacitor in the direction parallel to the capacitor plates. Once found, the performance of the topology-optimized geometries has been validated by transferring them to conventional electrokinetic models not relying on the artificial design field. Our results show the importance of the topology and shape of the dielectric solid in ICEO systems and point to new designs of ICEO micropumps with significantly improved performance.

  20. Nonuniform electro-osmotic flow on charged strips and its use in particle trapping. (United States)

    Liu, Shui-Jin; Hwang, Shyh-Hong; Wei, Hsien-Hung


    In this article, we investigate theoretically electro-osmotic flow set up by charged strips on an otherwise uncharged surface. Starting with a single-strip problem we demonstrate that for simple polynomial surface charge distributions several basic solutions can be derived in closed forms constituted by the analogous idea-flow solutions, which provide a more lucid way of revealing the flow features. These solutions reveal two types of flow topology: simple draining-in/pumping-out streaming and a pair of microvortices for symmetric and antisymmetric surface charge distributions, respectively. For an arbitrary surface charge distribution, more complicated flow structures can be found by the superposition of these basic solutions. We further extend the analysis to two uniformly charged strips and show how the flow characteristics vary with the strips' dimensions and surface zeta potentials. The far-field velocity behavior is also asymptotically identified and indicates that the hydrodynamic nature of the flow is typically long-range. An application to particle trapping with electro-osmotic vortices is also investigated theoretically for the first time. We show that in collaboration with short-range attraction effects the trapping can be facilitated by symmetric vortices with a converging stagnation point, but not by asymmetric vortices.

  1. Analysis of electro-osmotic flow in a microchannel with undulated surfaces

    CERN Document Server

    Yoshida, Hiroaki; Washizu, Hitoshi


    The electro-osmotic flow through a channel between two undulated surfaces induced by an external electric field is investigated. The gap of the channel is very small and comparable to the thickness of the electrical double layers. A lattice Boltzmann simulation is carried out on the model consisting of the Poisson equation for electrical potential, the Nernst--Planck equation for ion concentration, and the Navier--Stokes {\\color{black}equations} for flows of the electrolyte solution. An analytical model that predicts the flow rate is also derived under the assumption that the channel width is very small compared with the characteristic length of the variation along the channel. The analytical results are compared with the numerical results obtained by using the lattice Boltzmann method. In the case of a constant surface charge density along the channel, the variation of the channel width reduces the electro-osmotic flow, and the flow rate is smaller than that of a straight channel. In the case of a surface ch...

  2. Electro-osmotic flow of a second-grade fluid in a porous microchannel subject to an AC electric field

    Institute of Scientific and Technical Information of China (English)



    Studies on electro-osmotic flows of various types of fluids in microcharmel are of great importance owing to their multifold applications in the transport of liquids,particularly when the ionized liquid flows with respect to a charged surface in the presence of an external electric field.In the case of viscoelastic fluids,the volumetric flow rate differs significantly from that of Newtonian fluids,even when the flow takes place under the same pressure gradient and the same electric field.With this end in view,this paper is devoted to a study concerning the flow pattern of an electro-osmotic flow in a porous microchannel,which is under the action of an alternating electric field.The influence of various rheologieal and electro-osmotic parameters,e.g.,the Reynolds number,Debye-Huckel parameter,shape factor and fluid viscoelasticity on the kinematics of the fluid,has been investigated for a second-grade viscoelastic fluid.The problem is first treated by using analytical methods,but the quantitative estimates are obtained numerically with the help of the software MATHEMATICA.The results presented here are applicable to the cases where the channel height is much greater than the thickness of the electrical double layer comprising the Stern and diffuse layers.The study reveals that a larger value of the Debye-Huckel parameter creates sharper profile near the wall and also that the velocity of electro-osmotic flow increases as the permeability of the porous microchannel is enhanced.The study further shows that the electro-osmotic flow dominates at lower values of Reynolds number.The results presented here will be quite useful to validate the observations of experimental investigations on the characteristics of electro-osmotic flows and also the results of complex numerical models that are necessary to deal with more realistic situations,where electro-osmotic flows come into the picture,as in blood flow in the micro-circulatory system subject to an electric field.

  3. Experimental verification of overlimiting current by surface conduction and electro-osmotic flow in microchannels. (United States)

    Nam, Sungmin; Cho, Inhee; Heo, Joonseong; Lim, Geunbae; Bazant, Martin Z; Moon, Dustin Jaesuk; Sung, Gun Yong; Kim, Sung Jae


    Direct evidence is provided for the transition from surface conduction (SC) to electro-osmotic flow (EOF) above a critical channel depth (d) of a nanofluidic device. The dependence of the overlimiting conductance (OLC) on d is consistent with theoretical predictions, scaling as d(-1) for SC and d(4/5) for EOF with a minimum around d=8  μm. The propagation of transient deionization shocks is also visualized, revealing complex patterns of EOF vortices and unstable convection with increasing d. This unified picture of surface-driven OLC can guide further advances in electrokinetic theory, as well as engineering applications of ion concentration polarization in microfluidics and porous media.

  4. Suppression of nano-channel ion conductance by electro-osmotic flow

    CERN Document Server

    Liu, Yang; Zhu, Xin; Ran, Qiushi; Dutton, Robert


    This theoretical study concerns a basic understanding of ion transport in nano-channels that have weakly overlapping electric double layers. Numerical simulations reveal that the electro-osmotic flow (EOF) interplays with the concentration-polarization process and drives the ion depletion zone into the channels, thus significantly suppressing the channel conductance. The conductance may be restored at high electrical biases in the presence of recirculating vortices within the channels. Further analysis are conducted based on a 1-D, long channel model, and analytic expressions derived to quantitatively account for the EOF-driven ion depletion process. A limiting-conductance behavior is revealed as intrinsically different from the classical limiting-current behavior.

  5. Transport and reaction of nanoliter samples in a microfluidic reactor using electro-osmotic flow (United States)

    Arumbuliyur Comandur, Kaushik; Bhagat, Ali Asgar S.; Dasgupta, Subhashish; Papautsky, Ian; Banerjee, Rupak K.


    The primary focus of the paper is to establish both numerical and experimental methods to control the concentration of samples in a microreactor well. The concentration of the reacting samples is controlled by varying the initial sample size and electric field. Further, the paper numerically investigates the feasibility of mixing and reacting nanoliter samples with a wide variation in reaction rates in the microreactor driven by electro-osmotic pumping. Two discrete samples are measured and transported to the microreactor simultaneously by electro-osmotic pinching and switching. The transported samples are mixed in the microreactor and floated for 4.5 s for reaction to occur. It is seen that the normalized concentration of the product increases from 0.25 to 0.45 during that period. Also the effects of sample size and applied electric field on sample concentration during the switching process are studied. It is found that the normalized final sample concentration increases from 0.03 to 0.11 with an increase in sample size from 60 to 150 µm, at a constant electric field. Further, by increasing the electric field from 100 to 1000 V cm-1, at a constant sample size, there is a significant decrease in the final concentration of the sample from 0.14 to 0.04. Our studies also show that the normalized product concentration depends on the reaction rate and increases from 0.28 to 0.48 as the reaction rate increases from 10 L mol-1 s-1 to 105 L mol-1 s-1. However, the increase in the reaction rate beyond 105 L mol-1 s-1 does not influence the product concentration for the present design of the microreactor. Our microreactor with improved mixing can be used for assessing reactions of biological samples. The optimized sample size along with a controlled electric field for sample injection forms the basis for developing a prototype of a microreactor device for high throughput drug screening.

  6. Electro-osmotic flow of power-law fluid and heat transfer in a micro-channel with effects of Joule heating and thermal radiation (United States)

    Shit, G. C.; Mondal, A.; Sinha, A.; Kundu, P. K.


    A mathematical model has been developed for studying the electro-osmotic flow and heat transfer of bio-fluids in a micro-channel in the presence of Joule heating effects. The flow of bio-fluid is governed by the non-Newtonian power-law fluid model. The effects of thermal radiation and velocity slip condition have been examined in the case of hydrophobic channel. The Poisson-Boltzmann equation governing the electrical double layer field and a body force generated by the applied electric potential field are taken into consideration. The results presented here pertain to the case where the height of the channel is much greater than the thickness of electrical double layer comprising the Stern and diffuse layers. The expressions for flow characteristics such as velocity, temperature, shear stress and Nusselt number have been derived analytically under the purview of the present model. The results estimated on the basis of the data available in the existing scientific literatures are presented graphically. The effects of thermal radiation have an important bearing on the therapeutic procedure of hyperthermia, particularly in understanding the heat transfer in micro-channel in the presence of electric potential. The dimensionless Joule heating parameter has a reducing impact on Nusselt number for both pseudo-plastic and dilatant fluids, nevertheless its impact on Nusselt number is more pronounced for dilatant fluid. Furthermore, the effect of viscous dissipation has a significant role in controlling heat transfer and should not be neglected.

  7. Electro-osmotic-based catholyte production by Microbial Fuel Cells for carbon capture. (United States)

    Gajda, Iwona; Greenman, John; Melhuish, Chris; Santoro, Carlo; Li, Baikun; Cristiani, Pierangela; Ieropoulos, Ioannis


    In Microbial Fuel Cells (MFCs), the recovery of water can be achieved with the help of both active (electro-osmosis), and passive (osmosis) transport pathways of electrolyte through the semi-permeable selective separator. The electrical current-dependent transport, results in cations and electro-osmotically dragged water molecules reaching the cathode. The present study reports on the production of catholyte on the surface of the cathode, which was achieved as a direct result of electricity generation using MFCs fed with wastewater, and employing Pt-free carbon based cathode electrodes. The highest pH levels (>13) of produced liquid were achieved by the MFCs with the activated carbon cathodes producing the highest power (309 μW). Caustic catholyte formation is presented in the context of beneficial cathode flooding and transport mechanisms, in an attempt to understand the effects of active and passive diffusion. Active transport was dominant under closed circuit conditions and showed a linear correlation with power performance, whereas osmotic (passive) transport was governing the passive flux of liquid in open circuit conditions. Caustic catholyte was mineralised to a mixture of carbonate and bicarbonate salts (trona) thus demonstrating an active carbon capture mechanism as a result of the MFC energy-generating performance. Carbon capture would be valuable for establishing a carbon negative economy and environmental sustainability of the wastewater treatment process.

  8. Nongassing long-lasting electro-osmotic pump with polyaniline-wrapped aminated graphene electrodes. (United States)

    Kumar, Rudra; Jahan, Kousar; Nagarale, Rajaram K; Sharma, Ashutosh


    An efficient nongassing electro-osmotic pump (EOP) with long-lasting electrodes and exceptionally stable operation is developed by using novel flow-through polyaniline (PANI)-wrapped aminated graphene (NH2-G) electrodes. The NH2-G/PANI electrode combines the excellent oxidation/reduction capacity of PANI with the exceptional conductivity and inertness of NH2-G. The flow rate varies linearly with voltage but is highly dependent on the electrode composition. The flow rates at a potential of 5 V for pristine NH2-G and PANI electrodes are 71 and 100 μL min(-1) cm(-2), respectively, which increase substantially by the use of NH2-G/PANI electrode. It increased from 125 to 182 μL min(-1) cm(-2) as the fraction of aniline increased from 66.63 to 90.90%. The maximum flux obtained is 40 μL min(-1) V(-1) cm(-2) with NH2-G/PANI-90.9 electrodes. The assembled EOP remained exceptionally stable until the electrode columbic capacity was fully utilized. The prototype shown here delivered 8.0 μL/min at a constant applied voltage of 2 V for over 7 h of continuous operation. The best EOP produces a maximum stall pressure of 3.5 kPa at 3 V. These characteristics make it suitable for a variety of microfluidic/device applications.

  9. Effects of Micromachining Processes on Electro-Osmotic Flow Mobility of Glass Surfaces

    Directory of Open Access Journals (Sweden)

    Norihisa Miki


    Full Text Available Silica glass is frequently used as a device material for micro/nano fluidic devices due to its excellent properties, such as transparency and chemical resistance. Wet etching by hydrofluoric acid and dry etching by neutral loop discharge (NLD plasma etching are currently used to micromachine glass to form micro/nano fluidic channels. Electro-osmotic flow (EOF is one of the most effective methods to drive liquids into the channels. EOF mobility is affected by a property of the micromachined glass surfaces, which includes surface roughness that is determined by the manufacturing processes. In this paper, we investigate the effect of micromaching processes on the glass surface topography and the EOF mobility. We prepared glass surfaces by either wet etching or by NLD plasma etching, investigated the surface topography using atomic force microscopy, and attempted to correlate it with EOF generated in the micro-channels of the machined glass. Experiments revealed that the EOF mobility strongly depends on the surface roughness, and therefore upon the fabrication process used. A particularly strong dependency was observed when the surface roughness was on the order of the electric double layer thickness or below. We believe that the correlation described in this paper can be of great help in the design of micro/nano fluidic devices.

  10. Combining Electro-Osmotic Flow and FTA® Paper for DNA Analysis on Microfluidic Devices

    Directory of Open Access Journals (Sweden)

    Ryan Wimbles


    Full Text Available FTA® paper can be used to protect a variety of biological samples prior to analysis, facilitating ease-of-transport to laboratories or long-term archive storage. The use of FTA® paper as a solid phase eradicates the need to elute the nucleic acids from the matrix prior to DNA amplification, enabling both DNA purification and polymerase chain reaction (PCR-based DNA amplification to be performed in a single chamber on the microfluidic device. A disc of FTA® paper, containing a biological sample, was placed within the microfluidic device on top of wax-encapsulated DNA amplification reagents. The disc containing the biological sample was then cleaned up using Tris-EDTA (TE buffer, which was passed over the disc, via electro-osmotic flow, in order to remove any potential inhibitors of downstream processes. DNA amplification was successfully performed (from buccal cells, whole blood and semen using a Peltier thermal cycling system, whereupon the stored PCR reagents were released during the initial denaturing step due to the wax barrier melting between the FTA® disc and PCR reagents. Such a system offers advantages in terms of a simple sample introduction interface and the ability to process archived samples in an integrated microfluidic environment with minimal risk of contamination.

  11. Numerical study of active control of mixing in electro-osmotic flows by temperature difference using lattice Boltzmann methods. (United States)

    Alizadeh, A; Wang, J K; Pooyan, S; Mirbozorgi, S A; Wang, M


    In this paper, the effect of temperature difference between inlet flow and walls on the electro-osmotic flow through a two-dimensional microchannel is investigated. The main objective is to study the effect of temperature variations on the distribution of ions and consequently internal electric potential field, electric body force, and velocity fields in an electro-osmotic flow. We assume constant temperature and zeta potential on walls and use the mean temperature of each cross section to characterize the Boltzmann ion distribution across the channel. Based on these assumptions, the multiphysical transports are still able to be described by the classical Poisson-Boltzmann model. In this work, the Navier-Stokes equation for fluid flow, the Poisson-Boltzmann equation for ion distribution, and the energy equation for heat transfer are solved by a couple lattice Boltzmann method. The modeling results indicate that the temperature difference between walls and the inlet solution may lead to two symmetrical vortices at the entrance region of the microchannel which is appropriate for mixing enhancements. The advantage of this phenomenon for active control of mixing in electro-osmotic flow is the manageability of the vortex scale without extra efforts. For instance, the effective domain of this pattern could broaden by the following modulations: decreasing the external electric potential field, decreasing the electric double layer thickness, or increasing the temperature difference between inlet flow and walls. This work may provide a novel strategy for design or optimization of microsystems. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Suppression of ion conductance by electro-osmotic flow in nano-channels with weakly overlapping electrical double layers (United States)

    Liu, Yang; Guo, Lingzi; Zhu, Xin; Ran, Qiushi; Dutton, Robert


    This theoretical study investigates the nonlinear ionic current-voltage characteristics of nano-channels that have weakly overlapping electrical double layers. Numerical simulations as well as a 1-D mathematical model are developed to reveal that the electro-osmotic flow (EOF) interplays with the concentration-polarization process and depletes the ion concentration inside the channels, thus significantly suppressing the channel conductance. The conductance may be restored at high electrical biases in the presence of recirculating vortices within the channels. As a result of the EOF-driven ion depletion, a limiting-conductance behavior is identified, which is intrinsically different from the classical limiting-current behavior.

  13. Suppression of ion conductance by electro-osmotic flow in nano-channels with weakly overlapping electrical double layers

    Directory of Open Access Journals (Sweden)

    Yang Liu


    Full Text Available This theoretical study investigates the nonlinear ionic current-voltage characteristics of nano-channels that have weakly overlapping electrical double layers. Numerical simulations as well as a 1-D mathematical model are developed to reveal that the electro-osmotic flow (EOF interplays with the concentration-polarization process and depletes the ion concentration inside the channels, thus significantly suppressing the channel conductance. The conductance may be restored at high electrical biases in the presence of recirculating vortices within the channels. As a result of the EOF-driven ion depletion, a limiting-conductance behavior is identified, which is intrinsically different from the classical limiting-current behavior.

  14. A perturbative thermal analysis for an electro-osmotic flow in a slit microchannel based on a Lubrication theory (United States)

    Ramos, Ali; Mendez, Federico; Bautista, Oscar; Lizardi, José


    In this work, we develop a new thermal analysis for an electro-osmotic flow in a rectangular microchannel. The central idea is very simple: the Debye length that defines the length of the electrical double-layer depends on temperature T. Therefore, if exists any reason to include variable temperature effects, the above length should be utilized with caution because it appears in any electro-osmotic mathematical model. For instance, the presence of the Joule effect is a source that can generate important longitudinal temperature gradients along the microchannel and the isothermal hypothesis is no longer valid. In this manner, the Debye length is altered and as a consequence, new longitudinal temperature gradient terms appear into the resulting governing equations. These terms are enough to change the electric potential and the flow field. Taking into account the above comments, in the present study the momentum equations together with the energy, Poisson and Ohmic current conservation equations are solved by using a regular perturbation technique. For this purpose, we introduce a dimensionless parameter α that measures the temperature deviations of a reference temperature.

  15. Electro-osmotic pumping and ionic conductance measurements in porous membranes (United States)

    Vajandar, Saumitra K.

    Electro-osmotic (EO) pumps directly convert electrical energy into fluids' kinetic energy, which have many advantages such as a simple and compact structure, no mechanical moving parts, and easy integration. In general, it is easy for EO pumps to generate enough pressure but it has been a challenge for EO pumps to produce a high flowrate. EO pumps have found applications in various micro-/nano-electro-mechanical systems (MEMS/NEMS) and have the potential to impact a variety of engineering fields including microelectronics cooling and bio-analytical systems. This dissertation focuses on the design, fabrication and characterization of EO pumps based on two novel porous membrane materials: SiO2-coated anodic porous alumina and SiNx-coated porous silicon. High quality porous alumina membranes of controllable pore diameters in the range of 30-100 nm and pore lengths of 60-100 mum were fabricated by electrochemical anodization. The pores are straight, uniform and hexagonally close-packed with a high porosity of up to 50%. The inner surface of the pore was coated with a thin layer (˜5 nm) of SiO2 conformally to achieve a high zeta potential. The EO pumping flowrate of the fabricated anodic alumina membranes, coated and uncoated, was experimentally measured. Results indicate that the high zeta potential of the SiO2 coating increases the pumping flowrate even though the coating reduces the porosity of the membrane. The nanostructured SiO2-coated porous anodic alumina membranes can provide a normalized flowrate of 0.125 ml/min/V/cm2 under a low effective applied voltage of 3 V, which sets a record high normalized flowrate under low applied voltage. To realize field effect control of EO pumping, we designed and fabricated SiNx-coated porous silicon membranes with the silicon core as the electrode to apply a transverse gate potential. The gate potential will modulate the zeta potential of the pore wall and thereby provide control over the EO flowrate. The membranes were

  16. Debye-H¨uckel solution for steady electro-osmotic flow of micropolar fluid in cylindrical microcapillary

    Institute of Scientific and Technical Information of China (English)



    Analytic expressions for speed, flux, microrotation, stress, and couple stress in a micropolar fluid exhibiting a steady, symmetric, and one-dimensional electro-osmotic flow in a uniform cylindrical microcapillary were derived under the constraint of the Debye-H¨uckel approximation, which is applicable when the cross-sectional radius of the microcapillary exceeds the Debye length, provided that the zeta potential is sufficiently small in magnitude. Since the aciculate particles in a micropolar fluid can rotate without translation, micropolarity affects the fluid speed, fluid flux, and one of the two non-zero components of the stress tensor. The axial speed in a micropolar fluid intensifies when the radius increases. The stress tensor is confined to the region near the wall of the mi-crocapillary, while the couple stress tensor is uniform across the cross-section.

  17. Theory and design method for electro-osmotic consolidation%电渗排水固结的设计理论和方法

    Institute of Scientific and Technical Information of China (English)



    探讨了电渗法处理大面积深厚软土地基的若干问题,包括:电极材料、能耗、电源功率、设计理论和方法。EKG材料的出现解决了电极腐蚀和电渗能耗过高的问题,现在电渗法在大面积应用中面临的是电源功率要求过高的问题,该问题可以通过轮询通电的方法解决。依据电渗能级梯度理论提出了电渗排水固结的设计方法。时间因子和流量系数是电渗设计方法中的两个关键参数,其中流量系数具有较明显的模型尺寸效应,设计时需要进行修正。%The problems of electro-osmotic consolidation for large scale deep soft ground, including electrode, energy consumption, electric power, theory and design method, are discussed. Innovation of EKG materials has solved the problems of electrode corrosion and high energy consumption in electro-osmotic consolidation. High electric power demand is currently a new challenge for large scale application of electro-osmotic consolidation, and the solution will be the roll polling program embedded in novel designed electric power source. The design method based on the energy level gradient theory of electro-osmotic consolidation is proposed. The time factor and flow coefficient are the key parameters of the design method. The flow coefficient has distinct scale effect, and it needs to be corrected before applied in the design.

  18. Dispersion in oscillatory electro-osmotic flow through a parallel-plate channel with kinetic sorptive exchange at walls

    Institute of Scientific and Technical Information of China (English)



    Dispersion in time-oscillatory electro-osmotic flows in a slit micro-channel under the effect of kinetic sorptive exchange at walls is theoretically investigated using the homogenization method. The two walls of the channel are considered to be made up of different materials, and therefore have different zeta potentials and sorption coefficients. A general expression for the Taylor disper-sion coefficient under different zeta potentials as well as various sorption conditions at the walls is derived analytically. The disper-sion coefficient is found to be dependent on the oscillation frequency, the Debye parameter, the species partition coefficient, the rea-ction kinetics and the ratio of the wall potentials. The results demonstrate that the presence of wall sorption tends to enhance the dispersion when the oscillation frequency is low, but the effect is negligible in high-frequency oscillatory flows. Moreover, it is found that the dispersion coefficient could be significantly changed by adjusting the relative wall potentials for low-frequency flows.

  19. Electrical Potential, Mass Transport and Velocity Distribution of Electro-osmotic Flow in a Nanochannel by Incorporating the Variation of Dielectric Constant of Aqueous Electrolyte Solution

    CERN Document Server

    Padidhapu, Rajendra; Brahmajirao, V


    We consider a coupled system of Navier Stokes, Maxwell Stefan and Poisson Boltzmann equations by incorporating the variation of dielectric constant, which governs the electro osmotic flow in nano channel, describing the evolution of the velocity, concentration and potential fields of dissolved constituents in an aqueous electrolyte solution. We apply the finite difference technique to solve one and two dimensional systems of these equations. The solutions give an extremely accurate prediction of the dielectric constant for a variety of salts and a wide range of concentrations.

  20. Theory of fluid slip in charged capillary nanopores

    CERN Document Server

    Catalano, J; Biesheuvel, P M


    Based on the capillary pore model (space-charge theory) for combined fluid and ion flow through cylindrical nanopores or nanotubes, we derive the continuum equations modified to include wall slip. We focus on the ionic conductance and streaming conductance, cross-coefficients of relevance for electrokinetic energy conversion and electro-osmotic pumping. We combine the theory with a Langmuir-Stern 1-pK charge regulation boundary condition resulting in a non-monotonic dependence of the cross-coefficients on salt concentration.

  1. Development of a bi-functional silica monolith for electro-osmotic pumping and DNA clean-up/extraction using gel-supported reagents in a microfluidic device. (United States)

    Oakley, Jennifer A; Shaw, Kirsty J; Docker, Peter T; Dyer, Charlotte E; Greenman, John; Greenway, Gillian M; Haswell, Stephen J


    A silica monolith used to support both electro-osmotic pumping (EOP) and the extraction/elution of DNA coupled with gel-supported reagents is described. The benefits of the combined EOP extraction/elution system were illustrated by combining DNA extraction and gene amplification using the polymerase chain reaction (PCR) process. All the reagents necessary for both processes were supported within pre-loaded gels that allow the reagents to be stored at 4 degrees C for up to four weeks in the microfluidic device. When carrying out an analysis the crude sample only needed to be hydrodynamically introduced into the device which was connected to an external computer controlled power supply via platinum wire electrodes. DNA was extracted with 65% efficiency after loading lysed cells onto a silica monolith. Ethanol contained within an agarose gel matrix was then used to wash unwanted debris away from the sample by EOP (100 V cm(-1) for 5 min). The retained DNA was subsequently eluted from the monolith by water contained in a second agarose gel, again by EOP using an electric field of 100 V cm(-1) for 5 min, and transferred into the PCR reagent containing gel. The eluted DNA in solution was successfully amplified by PCR, confirming that the concept of a complete self-contained microfluidic device could be realised for DNA sample clean up and amplification, using a simple pumping and on-chip reagent storage methodology.

  2. Effect of interfacial Maxwell stress on time periodic electro-osmotic flow in a thin liquid film with a flat interface. (United States)

    Mayur, Manik; Amiroudine, Sakir; Lasseux, Didier; Chakraborty, Suman


    Electro-osmotic flows (EOF) have seen remarkable applications in lab-on-a-chip based microdevices owing to their lack of moving components, durability, and nondispersive nature of the flow profiles under specifically designed conditions. However, such flows may typically suffer from classical Faradaic artifacts like electrolysis of the solvent, which affects the flow rate control. Such a problem has been seen to be overcome by employing time periodic EOFs. Electric field induced transport of a conductive liquid is another nontrivial problem that requires careful study of interfacial dynamics in response to such an oscillatory flow actuation. The present study highlights the role of electric field generated Maxwell stress and free surface potential along with the electric double layer thickness and forcing frequency, toward influencing the interfacial transport and fluid flow in free-surface electro-osmosis under a periodically varying external electric field, in a semi-analytical formalism. Our results reveal interesting regimes over which the pertinent interfacial phenomena as well as bulk transport characteristics may be favorably tuned by employing time varying electrical fields.

  3. Analysis of metal ions migration to determine electro-osmotic flow for the in-situ cleanup of a tar-contaminated site

    KAUST Repository

    Lima, Ana T.


    An electro-osmosis experiment was set up on a former asphalt factory site, which is currently contaminated by tar, in Olst, the Netherlands. The main goal of this experiment was to remove polycyclic aromatic hydrocarbons (PAHs) from a contaminated clay layer by applying an electric gradient. But before calculating PAH removal, the direction and intensity of electro-osmosis have to be estimated. In field situations, tracers are used to get information about the water flow. In the present study, the inorganic elements concentration oscillations during electro-osmosis application are used as tracers. The experiment was set up in a clay layer, with the configuration 1m×1m×0.3m, at a depth of 4m below soil surface. Al, Ca, Cl, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, S, Si, Ti and Zn concentrations were determined in 28 measurements and were performed during the experimental period of 159days. Then they were used in a first evaluation where auto and cross-correlations were analyzed to aid in the geochemical interpretation and select the most conservative elements. The second part of this study is devoted to estimate the migration of water based on the concentrations development of Cl - at the anode and Na + at the cathode. Electro-osmotic flow was estimated to be intense (2.9 -10 -9-2.18 -10 -8m -s -1) during the first 10 to 50days of experiment and to cease after this period. © 2012.

  4. The huge shallow slip during the 2011 Tohoku-Oki earthquake as a result of very low coseismic shear strength of the Japan Trench décollement material (United States)

    Ujiie, K.; Tanaka, H.; Saito, T.; Tsutsumi, A.; Mori, J. J.; Kameda, J.


    Megathrust earthquakes commonly occur in subduction zones at depths where there is strong coupling between the plates and long-term strain accumulation. Unconsolidated sediments in the shallow plate-boundary décollement were thought to slip aseismically and have low levels of coupling. However, the 2011 Tohoku-Oki earthquake (Mw9.0) produced unprecedented slip of >50 m near the Japan Trench, resulting in the devastating tsunami. IODP Expedition 343, Japan Trench Fast Drilling Project (JFAST) successfully drilled the décollement in the maximum slip area of the 2011 earthquake. The décollement mostly consists of highly sheared pelagic clays. To investigate the mechanisms of the huge shallow seismic slip, we conducted high-velocity (1.3 m/s) friction experiments on the Japan Trench décollement material at normal stresses of ~2.0 MPa and displacements of ~60 m. To simulate both permeable and impermeable conditions during high-velocity shearing, the water-saturated gouge was placed between a pair of solid cylinders of porous Berea sandstone and Indian gabbro, respectively. The results show rapid slip weakening properties with very low peak and steady-state shear strength. The steady-state values for the effective coefficient of friction at normal stress of 2 MPa are 0.2 and 0.1 for the permeable and impermeable tests, respectively. The steady-state shear stress is independent of normal stress, suggesting the fluid-like behavior of the gouge during high-velocity shearing. The fluid-like behaved gouge is also supported by microstructural observations showing the evidence of fluidization effects such as injection structures and mixing flow. The axial displacement data indicate that the specimen compacted and dilated during permeable and impermeable tests, respectively. For the same amount of displacement, the temperature in the gouge is always smaller for the impermeable tests compared to the permeable tests. These results indicate that high-velocity weakening is more

  5. 电渗透/Fe-过硫酸盐氧化协同强化污泥深度脱水%Coordination of electro-osmotic and Fe-persulfate oxidation process on sewage sludge deep-dewatering

    Institute of Scientific and Technical Information of China (English)

    李亚林; 刘蕾; 张毅; 魏添; 史丹


    Dewatered sewage sludge of sewage treatment plant was studied by self-made experimental device dewatering based on electro-osmotic-advanced oxidation process which would be influenced by the dosage of persulfate, proportion of ferric salt and persulfate, voltage gradient and the thickness of dewatered sewage sludge. The results showed that the combination of electro-osmosis-advanced oxidation technology can improve the dewater ability. The water content can be reduced to below 60% with sludge amount of 140 g, persulfate dosage of 100 mg·(g DS)−1, Fe2+/persulfate of 1:1, mechanical pressure of 17.59 kPa and controlling initial voltage of 11 V·cm−1. Electro-osmotic-advanced oxidation process can ensure fully use of oxidation ability of4SO−i to improve the sludge dewater ability based on the mechanism of reduction of electric field and electronic metastasis reaction, making persulfate fully activated compared with sludge dewatering by activated persulfate. Better than the traditional electro-osmosis sludge dewatering, more amount sludge can be treated one time and sludge cake uniformity can be highly improved for the subsequent transportation and settlement.%利用电渗透和高级氧化技术,采用自制实验装置对城市污水处理厂的脱水污泥进行了脱水研究,系统研究了过硫酸盐投加量、铁盐与过硫酸盐比例、电压梯度、脱水时间和污泥厚度对污泥脱水的影响。结果表明,电渗透-高级氧化复合技术可以改善污泥的脱水性能,在污泥样品为140 g、过硫酸盐投加量为100(mg·g DS)−1、Fe2+与过硫酸盐比例为1:1、机械压力为17.59 kPa、控制初始电压为11 V·cm−1时,污泥的含水率可以降低至60%以下,与单独使用电渗透技术相比,泥饼具有更好的均匀性,便于后续的运输和安置。

  6. Connecting slow earthquakes to huge earthquakes. (United States)

    Obara, Kazushige; Kato, Aitaro


    Slow earthquakes are characterized by a wide spectrum of fault slip behaviors and seismic radiation patterns that differ from those of traditional earthquakes. However, slow earthquakes and huge megathrust earthquakes can have common slip mechanisms and are located in neighboring regions of the seismogenic zone. The frequent occurrence of slow earthquakes may help to reveal the physics underlying megathrust events as useful analogs. Slow earthquakes may function as stress meters because of their high sensitivity to stress changes in the seismogenic zone. Episodic stress transfer to megathrust source faults leads to an increased probability of triggering huge earthquakes if the adjacent locked region is critically loaded. Careful and precise monitoring of slow earthquakes may provide new information on the likelihood of impending huge earthquakes.

  7. Connecting slow earthquakes to huge earthquakes (United States)

    Obara, Kazushige; Kato, Aitaro


    Slow earthquakes are characterized by a wide spectrum of fault slip behaviors and seismic radiation patterns that differ from those of traditional earthquakes. However, slow earthquakes and huge megathrust earthquakes can have common slip mechanisms and are located in neighboring regions of the seismogenic zone. The frequent occurrence of slow earthquakes may help to reveal the physics underlying megathrust events as useful analogs. Slow earthquakes may function as stress meters because of their high sensitivity to stress changes in the seismogenic zone. Episodic stress transfer to megathrust source faults leads to an increased probability of triggering huge earthquakes if the adjacent locked region is critically loaded. Careful and precise monitoring of slow earthquakes may provide new information on the likelihood of impending huge earthquakes.


    Institute of Scientific and Technical Information of China (English)

    王军; 符洪涛; 蔡袁强; 曾芳金; 申矫健


    Taking into account the interaction between water flows and electrical currents as well as the pore pressure dissipation under the linear load,one dimensional electro-osmotic consolidation equation under linear load was established based on the extending consolidation process of the general seepage equation to the electro-osmotic field. The analytical solutions of the pole pressure and average degree of consolidation were given under two conditions of the cathode opened and anode closed and two poles opened. The effects of the maximum load and loading rate on the dissipation of pore pressure and the effect of supply voltage on theoretical consolidation degree and experimental consolidation degree were investigated by the method of parametric analysis and test analysis. The pore pressure dissipation curves in single and double drainage under different maximum loads and loading rates , and the curves of theoretical consolidation degree and experimental consolidation degree under different supply voltages were drawn. The results show that the greater maximum load and loading rate are,the faster dissipation speed of pore pressure is. At the same time,the effects of maximum load and loading rate on double drainage is greater than that on unilateral drainage. The greater supply voltage is,the higher the growth rate of theoretical consolidation degree and the experimental consolidation degree are,as well as the variable amplitude of theoretical consolidation degree is weaker than the variable amplitude of experimental consolidation degree in the period of time.%考虑线性堆载下水流和电流的相互作用以及孔隙水压力的消散情况,通过将单向渗流固结过程的普遍方程推广到电渗领域,建立线性堆载下软黏土一维电渗固结方程,并给出阴极排水、阳极不排水和阴阳极都排水2种情况下孔隙水压力和平均固结度的解析解。通过参数和试验分析,研究最大堆载和加载速率对孔隙水


    Directory of Open Access Journals (Sweden)



    Full Text Available Among all neural tube defects, encephalocele incidents are 1 in 5000 live births. (1 Newborn with encephalocele may be associated with other congenital malformations. Encephalocele patient’s management pose many challenge to neurosurgeon due to other associated anomalies that may present like ventriculocele, Dandy Walker and Arnold-Chiari malformation, and difficult positioning airway management to anaesthesiologist. We discuss a case of huge encephalocele and its management

  10. Intelligent Classification in Huge Heterogeneous Data Sets (United States)


    INTELLIGENT CLASSIFICATION IN HUGE HETEROGENEOUS DATA SETS JUNE 2015 FINAL TECHNICAL REPORT APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED...To) JUL 2013 – APR 2015 4. TITLE AND SUBTITLE INTELLIGENT CLASSIFICATION IN HUGE HETEROGENEOUS DATA SETS 5a. CONTRACT NUMBER IN-HOUSE 5b. GRANT...signals and through data dimension reduction, and to develop and tailor algorithms for the extraction of intelligence from several huge heterogeneous

  11. Outcome of Hepatectomy for Huge Hepatocellular Carcinoma. (United States)

    Jo, Sungho


    In spite of the recent improved results of hepatectomy for huge hepatocellular carcinomas (HCC), the prognosis of patients with huge HCCs is still poor compared to that of patients with small HCCs. This study was performed to compare the results of hepatectomy between patients with huge HCCs and those with small HCCs, to identify the prognostic factors in patients with huge HCCs, and to determine the preoperative selection criteria. We retrospectively analyzed 51 patients who underwent hepatectomy, between July 1994 and February 2009 at Dankook University Hospital. Patients with HCC≥10 cm were classified in large (L) group and others were classified in small (S) group. The clinicopathological features, operative procedures, and postoperative outcome were compared between both groups and various prognostic factors were investigated in group L. Eleven patients were classified in group L. Tumor size, vascular invasion, and tumor stage were higher in group L. Postoperative morbidity was higher in group L, but mortality was not different between the groups. Disease-free survivals were significantly lower in group L than in group S (36.4%, and 24.2% vs. 72.0%, and 44.0% for 1- and 3-year), but overall survival rates were similar in both groups (45.5%, and 15.2% in group L vs. 60.3%, and 41.3% in group S for 3- and 5-year). Presence of satellite nodules was the only prognostic factor in multivariate analysis after surgery for huge HCC. Regardless of tumor size, huge HCCs deserve consideration for surgery in patients with preserved liver function. Furthermore, the effect of surgery could be maximized with appropriate selection criteria, such as huge HCC without satellite nodules.

  12. Are non-slip socks really 'non-slip'? An analysis of slip resistance


    Haines Terrence; Chari Satyan; Varghese Paul; Economidis Alyssia


    Abstract Background Non-slip socks have been suggested as a means of preventing accidental falls due to slips. This study compared the relative slip resistance of commercially available non-slip socks with other foot conditions, namely bare feet, compression stockings and conventional socks, in order to determine any traction benefit. Methods Phase one involved slip resistance testing of two commercially available non-slip socks and one compression-stocking sample through an independent blind...

  13. Treatment strategies for huge central neurocytomas. (United States)

    Xiong, Zhong-wei; Zhang, Jian-jian; Zhang, Ting-bao; Sun, Shou-jia; Wu, Xiao-lin; Wang, Hao; You, Chao; Wang, Yu; Zhang, Hua-qiu; Chen, Jin-cao


    Central neurocytomas (CNs), initially asymptomatic, sometimes become huge before detection. We described and analyzed the clinical, radiological, operational and outcome data of 13 cases of huge intraventricular CNs, and discussed the treatment strategies in this study. All huge CNs (n=13) in our study were located in bilateral lateral ventricle with diameter ≥5.0 cm and had a broad-based attachment to at least one side of the ventricle wall. All patients received craniotomy to remove the tumor through transcallosal or transcortical approach and CNs were of typical histologic and immunohistochemical features. Adjuvant therapies including conventional radiation therapy (RT) or gamma knife radiosurgery (GKRS) were also performed postoperatively. Transcallosal and transcortical approaches were used in 8 and 5 patients, respectively. Two patients died within one month after operation and 3 patients with gross total resection (GTR) were additionally given a decompressive craniectomy (DC) and/or ventriculoperitoneal shunt (VPS) as the salvage therapy. Six patients received GTR(+RT) and 7 patients received subtotal resection (STR)(+GKRS). Eight patients suffered serious complications such as hydrocephalus, paralysis and seizure after operation, and patients who underwent GTR showed worse functional outcome [less Karnofsky performance scale (KPS) scores] than those having STR(+GKRS) during the follow-up period. The clinical outcome of huge CNs seemed not to be favorable as that described in previous reports. Surgical resection for huge CNs should be meticulously considered to guarantee the maximum safety. Better results were achieved in STR(+GKRS) compared with GTR(+RT) for huge CNs, suggesting that STR(+GKRS) may be a better treatment choice. The recurrent or residual tumor can be treated with GKRS effectively.

  14. A Huge Ancient Schwannoma of the Epiglottis. (United States)

    Lee, Dong Hoon; Kim, Jo Heon; Yoon, Tae Mi; Lee, Joon Kyoo; Lim, Sang Chul


    Ancient schwannoma of the epiglottis is extremely rare. The authors report the first case of a patient with a huge ancient schwannoma of the epiglottis. Clinicians should consider the possibility that ancient schwannoma may originate in the epiglottis mimicking the other more frequently observed lesions.

  15. Hydrodynamics of slip wedge and optimization of surface slip property

    Institute of Scientific and Technical Information of China (English)


    The hydrodynamic load support generated by a slip wedge of a slider bearing was studied. The surface slip property was optimized so that a maximum hydrodynamic load support could be obtained. A multi-linearity method was given for the slip control equation of two-dimensional (2-D) wall slip. We investigated 2-D wall slip and the hydrodynamics of a finite length bearing with any values of the surface limiting shear stress. It was found that the hydrodynamic effect of the slip wedge is greater than the traditional geometrical convergent-wedge. Even though the geo- metrical gap is a parallel or divergent sliding gap, the slip wedge still gives rise to a very big hydrodynamic pressure. The optimized slip wedge can give rise to a hy- drodynamic load support as high as 2.5 times of what the geometrical conver- gent-wedge can produce. Wall slip usually gives a small surface friction.

  16. Hydrodynamics of slip wedge and optimization of surface slip property

    Institute of Scientific and Technical Information of China (English)

    MA GuoJun; WU ChengWei; ZHOU Ping


    The hydrodynamic load support generated by a slip wedge of a slider bearing was studied. The surface slip property was optimized so that a maximum hydrodynamic load support could be obtained. A multi-linearity method was given for the slip control equation of two-dimensional (2-D) wall slip. We investigated 2-D wall slip and the hydrodynamics of a finite length bearing with any values of the surface limiting shear stress. It was found that the hydrodynamic effect of the slip wedge is greater than the traditional geometrical convergent-wedge. Even though the geometrical gap is a parallel or divergent sliding gap, the slip wedge still gives rise to a very big hydrodynamic pressure. The optimized slip wedge can give rise to a hydrodynamic load support as high as 2.5 times of what the geometrical convergent-wedge can produce. Wall slip usually gives a small surface friction.

  17. A huge presacral Tarlov cyst. Case report. (United States)

    Ishii, Kazuhiko; Yuzurihara, Masahito; Asamoto, Shunji; Doi, Hiroshi; Kubota, Motoo


    Perineural cysts have become a common incidental finding during lumbosacral magnetic resonance (MR) imaging. Only some of the symptomatic cysts warrant treatment. The authors describe the successful operative treatment of a patient with, to the best of their knowledge, the largest perineural cyst reported to date. A 29-year-old woman had been suffering from long-standing constipation and low-back pain. During an obstetric investigation for infertility, the clinician discovered a huge presacral cystic mass. Computed tomography myelography showed the lesion to be a huge Tarlov cyst arising from the left S-3 nerve root and compressing the ipsilateral S-2 nerve. The cyst was successfully treated by ligation of the cyst neck together with sectioning of the S-3 nerve root. Postoperative improvement in her symptoms and MR imaging findings were noted. Identification of the nerve root involved by the cyst wall, operative indication, operative procedure, and treatment of multiple cysts are important preoperative considerations.

  18. From tiny microalgae to huge biorefineries


    Gouveia, L.


    Microalgae are an emerging research field due to their high potential as a source of several biofuels in addition to the fact that they have a high-nutritional value and contain compounds that have health benefits. They are also highly used for water stream bioremediation and carbon dioxide mitigation. Therefore, the tiny microalgae could lead to a huge source of compounds and products, giving a good example of a real biorefinery approach. This work shows and presents examples of experimental...

  19. A rare clinic entity: Huge trichobezoar

    Directory of Open Access Journals (Sweden)

    Hidayatullah Hamidi, Dr, MD


    Conclusion: Trichobezoars should be suspected in young females with long standing upper abdominal masses; as the possibility of malignancy is not very common in this age group. While USG is inconclusive, trichobezoar can be accurately diagnosed with CT. In patient with huge trichobezoar, laparotomy can be performed firstly because of big size and location of mass, and psychiatric recommendation should be made to prevent relapse of this entity.

  20. Tensorial hydrodynamic slip

    CERN Document Server

    Bazant, Martin Z


    We describe a tensorial generalization of the Navier slip boundary condition and illustrate its use in solving for flows around anisotropic textured surfaces. Tensorial slip can be derived from molecular or microstructural theories or simply postulated as an constitutive relation, subject to certain general constraints on the interfacial mobility. The power of the tensor formalism is to capture complicated effects of surface anisotropy, while preserving a simple fluid domain. This is demonstrated by exact solutions for laminar shear flow and pressure-driven flow between parallel plates of arbitrary and different textures. From such solutions, the effects of rotating a texture follow from simple matrix algebra. Our results may be useful to extracting local slip tensors from global measurements, such as the permeability of a textured channel or the force required to move a patterned surface, in experiments or simulations.

  1. Laparoscopic Management of Huge Cervical Myoma. (United States)

    Peker, Nuri; Gündoğan, Savaş; Şendağ, Fatih

    To demonstrate the feasibility of laparoscopic management of a huge cervical myoma. Step-by-step video demonstration of the surgical procedure (Canadian Task Force classification III-C). Uterine myoma is the most common benign neoplasm of the female reproductive tract, with an estimated incidence of 25% to 30% at reproductive age [1,2]. Patients generally have no symptoms; however, those with such symptoms as severe pelvic pain, heavy uterine bleeding, or infertility may be candidates for surgery. The traditional management is surgery; however, uterine artery embolization or hormonal therapy using a gonadotropin-releasing hormone agonist or a selective estrogen receptor modulator should be preferred as the medical approach. Surgical management should be performed via laparoscopy or laparotomy; however, the use of laparoscopic myomectomy is being debated for patients with huge myomas. Difficulties in the excision, removal, and repair of myometrial defects, increased operative time, and blood loss are factors keeping physicians away from laparoscopic myomectomy [1,2]. A 40-year-old gravida 0, para 0 woman was admitted to our clinic with complaints of chronic pelvic pain, dyspareunia, and infertility. Her health history was unremarkable. Ultrasonographic examination revealed a 14 × 10-cm myoma in the cervical region. On bimanual examination, an immobile solid mass originating from the uterine cervix and filling the pouch of Douglas was palpated. The patient was informed of the findings, and laparoscopic myomectomy was recommended because of her desire to preserve her fertility. Abdominopelvic examination revealed a huge myoma filling and enlarging the cervix. Myomectomy was performed using standard technique as described elsewhere. A transverse incision was made using a harmonic scalpel. The myoma was fixed with a corkscrew manipulator and enucleated. Once bleeding was controlled, the myoma bed was filled with Spongostan to prevent possible bleeding from leakage

  2. Huge music archives on mobile devices

    DEFF Research Database (Denmark)

    Blume, H.; Bischl, B.; Botteck, M.


    The availability of huge nonvolatile storage capacities such as flash memory allows large music archives to be maintained even in mobile devices. With the increase in size, manual organization of these archives and manual search for specific music becomes very inconvenient. Automated dynamic...... and difficult to tackle on mobile platforms. Against this background, we provided an overview of algorithms for music classification as well as their computation times and other hardware-related aspects, such as power consumption on various hardware architectures. For mobile platforms such as smartphones...

  3. Laparoscopic Management of Huge Myoma Nascendi. (United States)

    Peker, Nuri; Gündoğan, Savas; Şendağ, Fatih

    To demonstrate the feasibility of laparoscopic management of a huge myoma nascendi. Step-by-step video demonstration of the surgical procedure (Canadian Task Force classification III-C). Uterine myoma is the most common benign neoplasm of the female reproductive tract, with an estimated incidence of 25% to 30% at reproductive age [1,2]. Patients generally have no symptoms; however, those with such symptoms as severe pelvic pain, heavy uterine bleeding, or infertility may be candidates for surgery. The traditional management is surgery; however, uterine artery embolization or hormonal therapy using a gonadotropin-releasing hormone agonist or a selective estrogen receptor modulator should be preferred as the medical approach. Surgical management should be performed via laparoscopy or laparotomy; however, the use of laparoscopic myomectomy is being debated for patients with huge myomas. Difficulties in the excision, removal, and repair of myometrial defects, increased operative time, and blood loss are factors keeping physicians away from laparoscopic myomectomy [1,2]. A 35-year-old woman was admitted to our clinic with complaints of chronic pelvic pain and heavy menstrual bleeding. Her medical history included multiple hospitalizations for blood transfusions, along with a recently measured hemoglobin level of 9.5 g/dL and a hematocrit value of 29%. She had never been married and had no children. Pelvic ultrasonography revealed a 12 × 10-cm uterine myoma located on the posterior side of the corpus uteri and protruding through to the cervical channel. This was a huge intramural submucous myoma in close proximity to the endometrial cavity and spreading through the myometrium. On vaginal examination, the myoma was found to extend into the vagina through the cervical channel. Laparoscopic myomectomy was planned because of the patient's desire for fertility preservation. Abdominopelvic exploration revealed a huge myoma filling the posterior side of the corpus uteri and

  4. Huge Tongue Lipoma: A Case Report

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Damghani


    Full Text Available Introduction: Lipomas are among the most common tumors of the human body. However, they are uncommon in the oral cavity and are observed as slow growing, painless, and asymptomatic yellowish submucosal masses. Surgical excision is the treatment of choice and recurrence is not expected.    Case Report: The case of a 30-year-old woman with a huge lipoma on the tip of her tongue since 3 years, is presented. She had difficulty with speech and mastication because the tongue tumor was filling the oral cavity. Clinical examination revealed a yellowish lesion, measuring 8 cm in maximum diameter, protruding from the lingual surface. The tumor was surgically excised with restoration of normal tongue function and histopathological examination of the tumor confirmed that it was a lipoma.   Conclusion:  Tongue lipoma is rarely seen and can be a cause of macroglossia. Surgical excision for lipoma is indicated for symptomatic relief and exclusion of associated malignancy.

  5. Galaxies Collide to Create Hot, Huge Galaxy (United States)


    This image of a pair of colliding galaxies called NGC 6240 shows them in a rare, short-lived phase of their evolution just before they merge into a single, larger galaxy. The prolonged, violent collision has drastically altered the appearance of both galaxies and created huge amounts of heat turning NGC 6240 into an 'infrared luminous' active galaxy. A rich variety of active galaxies, with different shapes, luminosities and radiation profiles exist. These galaxies may be related astronomers have suspected that they may represent an evolutionary sequence. By catching different galaxies in different stages of merging, a story emerges as one type of active galaxy changes into another. NGC 6240 provides an important 'missing link' in this process. This image was created from combined data from the infrared array camera of NASA's Spitzer Space Telescope at 3.6 and 8.0 microns (red) and visible light from NASA's Hubble Space Telescope (green and blue).

  6. A rare clinic entity: Huge trichobezoar. (United States)

    Hamidi, Hidayatullah; Muhammadi, Marzia; Saberi, Bismillah; Sarwari, Mohammad Arif


    Trichobezoar is a rare clinical entity in which a ball of hair amasses within the alimentary tract. It can either be found as isolated mass in the stomach or may extend into the intestine. Trichobezoars mostly occur in young females with psychiatric disorders such as trichophagia and trichotillomania. Authors present a giant trichobezoar in an 18year old female presented with complaints of upper abdominal mass, epigastric area pain, anorexia and weight loss. The patient underwent trans-abdominal ultrasonography (USG), Computed tomography (CT), upper gastrointestinal endoscopy and subsequently laparotomy. USG was inconclusive due to non-specific findings. It revealed a thick echogenic layer with posterior dirty shadowing extending from the left sub-diaphragmatic area to the right sub hepatic region obscuring the adjacent structures. Abdominal CT images revealed a huge, well defined, multi-layered, heterogeneous, solid appearing, non-enhancing mass lesion in the gastric lumen extending from the gastric fundus to the pyloric canal. An endoscopic attempt was performed for removal of this intraluminal mass, but due to its large size, and hard nature, the endoscopic removal was unsuccessful. Finally the large trichobezoar was removed with open laparotomy. Trichobezoars should be suspected in young females with long standing upper abdominal masses; as the possibility of malignancy is not very common in this age group. While USG is inconclusive, trichobezoar can be accurately diagnosed with CT. In patient with huge trichobezoar, laparotomy can be performed firstly because of big size and location of mass, and psychiatric recommendation should be made to prevent relapse of this entity. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.



    BY ANCIENT ENCOUNTER This stunningly beautiful image [right] taken with the NASA Hubble Space Telescope shows the heart of the prototypical starburst galaxy M82. The ongoing violent star formation due to an ancient encounter with its large galactic neighbor, M81, gives this galaxy its disturbed appearance. The smaller picture at upper left shows the entire galaxy. The image was taken in December 1994 by the Kitt Peak National Observatory's 0.9-meter telescope. Hubble's view is represented by the white outline in the center. In the Hubble image, taken by the Wide Field and Planetary Camera 2, the huge lanes of dust that crisscross M82's disk are another telltale sign of the flurry of star formation. Below the center and to the right, a strong galactic wind is spewing knotty filaments of hydrogen and nitrogen gas. More than 100 super star clusters -- very bright, compact groupings of about 100,000 stars -- are seen in this detailed Hubble picture as white dots sprinkled throughout M82's central region. The dark region just above the center of the picture is a huge dust cloud. A collaboration of European and American scientists used these clusters to date the ancient interaction between M82 and M81. About 600 million years ago, a region called 'M82 B' (the bright area just below and to the left of the central dust cloud) exploded with new stars. Scientists have discovered that this ancient starburst was triggered by the violent encounter with M81. M82 is a bright (eighth magnitude), nearby (12 million light-years from Earth) galaxy in the constellation Ursa Major (the Great Bear). The Hubble picture was taken Sept. 15, 1997. The natural-color composite was constructed from three Wide Field and Planetary Camera 2 exposures, which were combined in chromatic order: 4,250 seconds through a blue filter (428 nm); 2,800 seconds through a green filter (520 nm); and 2,200 seconds through a red (820 nm) filter. Credits for Hubble image: NASA, ESA, R. de Grijs (Institute of

  8. Slip flow in graphene nanochannels (United States)

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


    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.

  9. Are non-slip socks really 'non-slip'? An analysis of slip resistance

    Directory of Open Access Journals (Sweden)

    Haines Terrence


    Full Text Available Abstract Background Non-slip socks have been suggested as a means of preventing accidental falls due to slips. This study compared the relative slip resistance of commercially available non-slip socks with other foot conditions, namely bare feet, compression stockings and conventional socks, in order to determine any traction benefit. Methods Phase one involved slip resistance testing of two commercially available non-slip socks and one compression-stocking sample through an independent blinded materials testing laboratory using a Wet Pendulum Test. Phase two of the study involved in-situ testing among healthy adult subjects (n = 3. Subjects stood unsupported on a variable angle, inclined platform topped with hospital grade vinyl, in a range of foot conditions (bare feet, non-slip socks, conventional socks and compression stockings. Inclination was increased incrementally for each condition until slippage of any magnitude was detected. The platform angle was monitored using a spatial orientation tracking sensor and slippage point was recorded on video. Results Phase one results generated through Wet Pendulum Test suggested that non-slip socks did not offer better traction than compression stockings. However, in phase two, slippage in compression stockings was detected at the lowest angles across all participants. Amongst the foot conditions tested, barefoot conditions produced the highest slip angles for all participants indicating that this foot condition provided the highest slip resistance. Conclusion It is evident that bare feet provide better slip resistance than non-slip socks and therefore might represent a safer foot condition. This study did not explore whether traction provided by bare feet was comparable to 'optimal' footwear such as shoes. However, previous studies have associated barefoot mobilisation with increased falls. Therefore, it is suggested that all patients continue to be encouraged to mobilise in appropriate, well

  10. Umbilicoplasty in children with huge umbilical hernia

    Directory of Open Access Journals (Sweden)

    Akakpo-Numado Gamedzi Komlatsè


    Full Text Available Background: Huge umbilical hernias (HUH are voluminous umbilical hernia (UH that are frequent in black African children. Several surgical techniques are used in their treatment for umbilical reconstruction, but techniques using skin flaps provide better aesthetic results. In this study, we presented our technique of umbilicoplasty in HUH, and its results. Patients and Methods: It is a retrospective study on children treated for HUH, from January 2012 to December 2013. The UH was called HUH when its basis diameter (BD exceeds 3 cm. Every HUH was characterised by its height, BD and morphology. Our technique was a two lateral flaps technique; the flaps are symmetrical and drawn so as to reconstitute the different parts of the umbilicus. The results were appreciated with criteria, including the peripheral ring and the central depression of the neo-umbilicus. Results : Twelve children were concerned (7 boys and 5 girls. Their mean age was 5 years and 6 months. The mean BD was 5.6 cm (extremes 3 and 8 cm, and the mean height of the HUH was 7.45 cm (extremes 3 and 9 cm. All underwent umbilicoplasty. In early post-operative period, two children presented a transitory subcutaneous hematoma. Late complications were granulation tissue with two children, and cheloid scar with one. With a mean follow-up of 10 months, we had 10 excellent results and two fair results according to our criteria. Conclusion: Our two lateral flaps umbilicoplasty is well-adapted to HUH in children. It is simple and assures a satisfactory anatomical and cosmetic result.

  11. Hepatectomy for huge hepatocellular carcinoma: single institute's experience. (United States)

    Yang, Lianyue; Xu, Jiangfeng; Ou, Dipeng; Wu, Wei; Zeng, Zhijun


    The surgical resection of huge hepatocellular carcinoma (HCC) is still controversial. This study was designed to introduce our experience of liver resection for huge HCC and evaluate the safety and outcomes of hepatectomy for huge HCC. A total of 258 hepatic resections for the patients with huge HCC were analysed retrospectively from December 2002 to December 2011. The operative outcomes were compared with 293 patients with HCC >5.0 cm but huge HCC group and HCC >5.0 cm but huge HCC group has significantly a more longer overall and disease-free survival time than nodular huge HCC (P = 0.026, P = 0.022). Univariate and multivariate analysis revealed that the types of tumour, vascular invasion, and UICC stage were independent prognostic factors for overall survival (P = 0.047, P = 0.037, P = 0.033). Hepatic resection can be performed safely for huge HCC with a low mortality and favorable survival outcomes. Solitary huge HCC has the better surgical outcomes than nodular huge HCC.

  12. Handling a slip | Smokefree 60+ (United States)

    Plan how you will recover from a slip—before it happens. You can recover from a slip If you do go back to smoking, you are not a failure. Don't toss aside your attempt as worthless. Use it to try and succeed. Think of your quit attempt as a learning experience, and if you do slip, try again.

  13. Optimization of Dynamically Generated SQL Queries for Tiny-Huge, Huge-Tiny Problem

    Directory of Open Access Journals (Sweden)

    Arjun K Sirohi


    Full Text Available In most new commercial business software applications like Customer Relationship Management, the datais stored in the database layer which is usually a Relational Database Management System (RDBMS likeOracle, DB2 UDB or SQL Server. To access data from these databases, Structured Query Language (SQLqueries are used that are generated dynamically at run time based on defined business models and businessrules. One such business rule is visibility- the capability of the application to restrict data access based onthe role and responsibility of the user logged in to the application. This is generally achieved by appendingsecurity predicates in the form of sub-queries to the main query based on the roles and responsibility of theuser. In some cases, the outer query may be more restrictive while in other cases, the security predicatesmay be more restrictive. This often results in a dilemma for the cost-based optimizer (CBO of the backenddatabase whether to drive from the outer query or drive from the security predicate sub-queries. Thisdilemma is sometimes called the “Tiny-Huge, Huge-Tiny” problem and results in serious performancedegradation by way of increased response times on the application User Interface (UI. This paperprovides a case study of a new approach to vastly reduce this CBO dilemma by a combination of denormalizedcolumns and re-writing of the security predicates’ sub-queries at run-time, thereby levelling theouter and security sub-queries. This approach results in more stable execution plans in the database andmuch better performance of such SQLs, effectively leading to higher performance and scalability of theapplication.

  14. Slips of the Typewriter Key. (United States)

    Berg, Thomas


    Presents an analysis of 500 submorphemic slips of the typewriter key that escaped the notice of authors and other proofreaders and thereby made their way into the published records of scientific research. (Author/VWL)

  15. Scarless surgery for a huge liver cyst: A case report. (United States)

    Kashiwagi, Hiroyuki; Kawachi, Jun; Isogai, Naoko; Ishii, Masanori; Miyake, Katsunori; Shimoyama, Rai; Fukai, Ryota; Ogino, Hidemitsu


    Symptomatic or complicated liver cysts sometimes require surgical intervention and laparoscopic fenestration is the definitive treatment for these cysts. We performed minimally invasive surgery, hybrid natural orifice transluminal endoscopic surgery (NOTES) without scarring, for a huge liver cyst. An 82-year-old female presented with a month-long history of right upper abdominal pain. We diagnosed her condition as a huge liver cyst by morphological studies. She denied any history of abdominal trauma. Her serum CEA and CA19-9 were normal and a serum echinococcus serologic test was negative. Laparoscopic fenestration, using a hybrid NOTES procedure via a transvaginal approach, was performed for a huge liver cyst because we anticipated difficulty with an umbilical approach, such as single incision laparoscopic surgery (SILS). Her post-operative course was uneventful and she was discharged from our hospital three days after surgery. Pain killers were not required during and after hospitalization. No recurrence of the liver cyst or bulging was detected by clinical examination two years later. A recent trend of laparoscopic procedure has been towards minimizing the number of incisions to achieve less invasiveness. This hybrid NOTES, with a small incision for abdominal access, along with vaginal access, enabled painless operation for a huge liver cyst. We report a huge liver cyst treated by hybrid NOTES. This approach is safe, less invasive, and may be the first choice for a huge liver cyst. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. Slipping rib syndrome in childhood. (United States)

    Mooney, D P; Shorter, N A


    Slipping rib syndrome is an unusual cause of lower chest and upper abdominal pain in children not mentioned in major pediatric surgical texts. The syndrome occurs when the medial fibrous attachments of the eighth, ninth, or tenth ribs are inadequate or ruptured, allowing their cartilage tip to slip superiorly and impinge on the intervening intercostal nerve. This may cause a variety of somatic and visceral complaints. Although the diagnosis may be made based on history and physical examination, lack of recognition of this disorder frequently leads to extensive diagnostic evaluations before definitive therapy. The authors report on four children who have this disorder.

  17. Slip flow in graphene nanochannels

    DEFF Research Database (Denmark)

    . Kannam, Sridhar; Billy, Todd; Hansen, Jesper Schmidt


    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...

  18. Whillans Ice Plain Stick Slip (United States)

    Lipovsky, B.; Dunham, E. M.


    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

  19. Simulation of an ac electro-osmotic pump with step microelectrodes (United States)

    Kim, Byoung Jae; Lee, Seung-Hyun; Rezazadeh, Soghra; Sung, Hyung Jin


    Pumps with step microelectrodes subjected to an ac voltage are known to have faster pumping rates than those with planar asymmetric microelectrodes. The driving force for pumping in these systems is ac electro-osmosis. This paper aims to understand the flow behaviors of pumps with step microelectrodes by using a realistic model applicable to high external voltages. This model takes the steric effect due to the finite sizes of ions into account and copes with the exponential sensitivity of the counterion concentration to voltage. The effects on the pumping flow rate of varying the pump parameters were investigated. The geometrical parameters were optimized, and the effects of varying the ac frequency and amplitude were examined. The electrical potential of the fluid and the electrical charge at the electrode surface were solved simultaneously, and the Stokes equation was used to describe the fluid flow.

  20. Numerical characterization of silicon DC electro-osmotic pumps: the role of the micro channel geometry


    Geri, M; Lorenzini, M.; Morini, GL; 3rd Micro and Nano Flows Conference (MNF2011)


    This paper was presented at the 3rd Micro and Nano Flows Conference (MNF2011), which was held at the Makedonia Palace Hotel, Thessaloniki in Greece. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, Aristotle University of Thessaloniki, University of Thessaly, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute. ...

  1. Mass flow-rate control through time periodic electro-osmotic flows in circular microchannels (United States)

    Chakraborty, Suman; Ray, Subhashis


    The present study is directed towards devising a scientific strategy for obtaining controlled time-periodic mass flow-rate characteristics through the employment of pulsating electric fields in circular microchannels by exploiting certain intrinsic characteristics of periodic electro-osmosis phenomenon. Within the assumption of thin electrical double layers, the governing equations for potential distribution and fluid flow are derived, corresponding to a steady base state and a time-varying perturbed state, by assuming periodic forms of the imposed electrical fields and the resultant velocity fields. For sinusoidal pulsations of the electric field superimposed over its mean, a signature map depicting the amplitudes of the mass flow rate and the electrical field as well as their phase differences is obtained from the theoretical analysis as a function of a nondimensional frequency parameter for different ratios of the characteristic electric double layer thickness relative to the microchannel radius. Distinctive characteristics in the signature profiles are obtained for lower and higher frequencies, primarily attributed to the finite time scale for momentum propagation away from the walls. The signature characteristics, obtained from the solution of the prescribed sinusoidal electric field, are subsequently used to solve the "inverse" problem, where the mass flow rate is prescribed in the form of sinusoidal pulsations and the desired electric fields that would produce the required mass flow-rate variations are obtained. The analysis is subsequently extended for controlled triangular and trapezoidal pulsations in the mass flow rate and the required electric fields are successfully obtained. It is observed that the higher the double layer thickness is in comparison to the channel radius, the more prominent is the deviation of the shape of the required electric field pulsation from the desired transience in the mass flow-rate characteristics. Possible extensions of the analysis to more complicated pulsation profiles are also outlined.

  2. Electro-osmotic transport of nano zero-valent iron in Boom Clay

    NARCIS (Netherlands)

    Rosales, E.; Loch, J.P.G.; Dias-Ferreira, C.


    One of the many problems that impede the successful remediation of soil and groundwater contaminated with chlorinated hydrocarbons occurs when pollutants diffuse into low permeability zones, and become difficultly accessible. Remediation by reductive dechlorination using nanoscale zero-valent iron

  3. Numerical characterization of silicon DC electro-osmotic pumps: the role of the micro channel geometry


    Geri, M; Lorenzini, M.; Morini, GL; 3rd Micro and Nano Flows Conference (MNF2011)


    This paper was presented at the 3rd Micro and Nano Flows Conference (MNF2011), which was held at the Makedonia Palace Hotel, Thessaloniki in Greece. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, Aristotle University of Thessaloniki, University of Thessaly, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute. ...

  4. Field-Effect Modulated Electro-Osmotic Pumps for High Precision Colloid Thrusters Project (United States)

    National Aeronautics and Space Administration — The ability to precisely control the position of satellites is a critical enabling technology for space missions involving interferometric arrays. One proposed...

  5. In situ electro-osmotic cleanup of tar contaminated soil—Removal of polycyclic aromatic hydrocarbons

    KAUST Repository

    Lima, Ana T.


    An in situ electro-osmosis experiment was set up in a tar contaminated clay soil in Olst, the Netherlands, at the site of a former asphalt factory. The main goal of this experiment was to remove polycyclic aromatic hydrocarbons (PAHs) from the contaminated clay layer by applying an electric gradient of 12 V m-1 across the soil over an electrode distance of 1 m. With the movement of water by electro-osmosis and the addition of a non-ionic surfactant (Tween 80), the non-polar PAHs were dragged along by convection and removed from the fine soil fraction. Soil samples were taken at the start and after 159 days at the end of the experiment. Water at the electrode wells was sampled regularly during the course of the experiment. The results reflect the heterogeneity of the soil characteristics and show the PAH concentrations within the experimental set up. After first having been released into the anolyte solution due to extraction by Tween 80 and subsequent diffusion, PAH concentrations increased significantly in the electrode reservoirs at the cathode side after 90 days of experiment. Although more detailed statistical analysis is necessary to quantify the efficiency of the remediation, it can be concluded that the use of electro-osmosis together with a non-ionic surfactant is a feasible technique to mobilize non-polar organic contaminants in clayey soils. Crown Copyright © 2011 Published by Elsevier Ltd. All rights reserved.

  6. Hydrodynamic slip in silicon nanochannels (United States)

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


    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.

  7. Slip rate and tremor genesis in Cascadia (United States)

    Wech, Aaron G.; Bartlow, Noel M.


    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.

  8. A case of a huge gastroepiploic arterial aneurysm. (United States)

    Ikeda, Hirokuni; Takeo, Masahiko; Mikami, Ryuuichi; Yamamoto, Mistuo


    An 85-year-old man complaining of vague abdominal discomfort was admitted to our hospital. A pulsatile 8 × 7-cm mass in the right upper abdomen was noticed on clinical examination. Computed tomography of the abdomen showed a huge arterial aneurysm in the right gastroepiploic artery, and the left gastroepiploic artery was meandering and expanding. An image diagnosis of gastroepiploic arterial aneurysm (GEAA) was made. Because of the huge size of the aneurysm and the predicted high risk of perforation, surgical intervention was planned. The aneurysm was identified in the greater curve and was found to adhere firmly to the transverse colon. Partial resection of the stomach, aneurysmectomy and partial resection of the transverse colon were performed. Clinically, splanchnic arterial aneurysms are rare. Among them, GEAA is especially rare. We report a rare case of a huge GEAA that was treated successfully by surgery. Published by Oxford University Press and JSCR Publishing Ltd. All rights reserved. © The Author 2015.

  9. Anaesthetic management in a case of huge plunging ranula. (United States)

    Sheet, Jagabandhu; Mandal, Anamitra; Sengupta, Swapnadeep; Jana, Debaleena; Mukherji, Sudakshina; Swaika, Sarbari


    Plunging ranula is a rare form of mucous retention cyst arising from submandibular and sublingual salivary glands, which may occasionally become huge occupying the whole of the floor of the mouth and extending into the neck, thus, restricting the neck movement as well as disfiguring the normal airway anatomy. Without fiberoptic assistance, blind or retrograde nasal intubation remains valuable choices in this type of situation. Here, we present a case of successful management of airway by blind nasal intubation in a patient posted for excision of a huge plunging ranula.

  10. Huge Gastric Teratoma in an 8-Year Old Boy. (United States)

    Sisodiya, Rajpal S; Ratan, Simmi K; Man, Parveen K


    Gastric teratoma is very rare tumor and usually presents in early infancy. An 8-year-old boy presented with a huge mass in abdomen extending from epigastrium to the pelvis. Ultrasound and CT scan of abdomen revealed a huge mass with solid and cystic components and internal calcifications. The preoperative diagnosis was a teratoma but not specifically gastric one. At operation, it was found to be gastric teratoma. The mass was excised completely with part of the stomach wall. The histopathology confirmed it to be mature gastric teratoma. The rarity of the teratoma with delayed presentation prompted us to report the case.

  11. Anaesthetic challenges in a patient presenting with huge neck teratoma

    Directory of Open Access Journals (Sweden)

    Gaurav Jain


    Full Text Available Paediatric airway management is a great challenge even for an experienced anaesthesiologist. Difficult airway in huge cervical teratoma further exaggerates the complexity. This case report is intended at describing the intubation difficulties that were confronted during the airway management of a three year old girl presenting with huge neck teratoma and respiratory distress. This patient was successfully intubated with uncuffed endotracheal tubes in second attempt under inhalational anaesthesia with halothane and spontaneous ventilation. This case exemplifies the importance of careful preoperative workup of an anticipated difficult airway in paediatric patients with neck swelling to minimize any perioperative complications.

  12. Huge pelvic mass secondary to wear debris causing ureteral obstruction. (United States)

    Hananouchi, Takehito; Saito, Masanobu; Nakamura, Nobuo; Yamamoto, Tetsuya; Yonenobu, Kazuo


    We report an unusual granulomatous reaction of wear debris that produced a huge pelvic mass causing ureteral obstruction. A 72-year-old woman, who received a cemented total hip arthroplasty 30 years ago, was referred to the department of gynecology for examination of a pelvic mass. A computed tomography scan revealed a huge homogenous mass, measuring approximately 20 x 16 x 12 cm, including extensive osteolysis of the left pelvis around the acetabular component. Intravenous pyelogram revealed complete obstruction of the left ureter resulting in hydronephrosis of the left kidney. Histological examination from the biopsy specimen detected polyethylene wear debris in the mass.

  13. Anaesthetic management in a case of huge plunging ranula (United States)

    Sheet, Jagabandhu; Mandal, Anamitra; Sengupta, Swapnadeep; Jana, Debaleena; Mukherji, Sudakshina; Swaika, Sarbari


    Plunging ranula is a rare form of mucous retention cyst arising from submandibular and sublingual salivary glands, which may occasionally become huge occupying the whole of the floor of the mouth and extending into the neck, thus, restricting the neck movement as well as disfiguring the normal airway anatomy. Without fiberoptic assistance, blind or retrograde nasal intubation remains valuable choices in this type of situation. Here, we present a case of successful management of airway by blind nasal intubation in a patient posted for excision of a huge plunging ranula. PMID:25886120

  14. Slipping properties of ceramic tiles / Quantification of slip resistance (United States)

    Terjek, Anita


    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.

  15. Imaging of huge lingual thyroid gland with goitre

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C.C.; Chen, C.Y.; Chen, F.H.; Lee, G.W.; Hsiao, H.S. [Nat. Defense Medical Centre, Taipei (Taiwan, Province of China). Dept. of Diagnostic Radiol.; Zimmermann, R.A. [Department of Radiology, The Children`s Hospital of Philadelphia, 34th St. and Civic Blvd., Philadelphia, PA 19014 (United States)


    We present the CT and MRI findings in a 75-year-old woman with a huge pathologically proven lingual thyroid which underwent goitrous degeneration. CT and MRI showed a midline, tongue-based, exophytic mass with areas of necrosis and heterogeneous contrast enhancement, as seen in large goitres in the normal thyroid gland. (orig.) With 1 fig., 7 refs.

  16. Smart Cities as Support and Legacy of Huge Sport Events

    Directory of Open Access Journals (Sweden)



    Full Text Available In this paper we discuss the concept of a smart city and the importance of huge Sport events as an incentive to the creation of the infrastructure necessary for the development of cities that provide quality of life for all its citizens using information technology.

  17. The big, large and huge case of state-building

    DEFF Research Database (Denmark)

    Harste, Gorm

      Using communication theory as point of departure, it is not evident how to study macro phenomena. Michel Foucault limited his studies to a non-Grand Theory when studying discursive events. At the same time, Charles Tilly wrote about Big Structures, Large Processes, Huge Comparisons when trying...

  18. [Experience of surgical treatment of huge mediastinal tumors]. (United States)

    Li, Yuanbo; Zhang, Yi; Xu, Qingsheng; Su, Lei; Zhi, Xiuyi; Wang, Ruotian; Qian, Kun; Hu, Mu; Liu, Lei


    The diagnosis and surgical treatment of 36 huge mediastinal tumors were summarized in order to evaluate the effect and safety of the operation. Thirty-six huge mediastinal tumor patients treated in our department from June 2006 to June 2013 were retrospective analyzed, of whom clinical manifestations, diagnosis, surgical treatment and prognosis were carefully collected. Twenty-three cases were men and 13 were women. The average age was 39.2 years old. The pathology turned out to be benign in 23 cases and malignant in 13 cases. Complete resection was achieved in 34 cases while palliative resection in 2 cases with no perioperative death. Six cases had developed postoperative complications but all recovered after active treatment. Patients who had been diagnosed with benign tumors were all alive after follow-up periods of 6 months to 7 years. Nine malignat tumor patients developed recurrence or metastasis, including seven deaths. Surgery played a vital role in the diagnosis and treatment of huge mediastinal tumors. Preoperative diagnosis, accurate surgical approach and careful operation were the key to successful treatment. Benign huge mediastinal tumors had excellent prognosis with surgery.

  19. A Huge Ovarian Dermoid Cyst: Successful Laparoscopic Total Excision. (United States)

    Uyanikoglu, Hacer; Dusak, Abdurrahim


    Giant ovarian cysts, ≥15 cm in diameter, are quite rare in women of reproductive age. Here, we present a case of ovarian cyst with unusual presentation treated by laparoscopic surgery. On histology, mass was found to be mature cystic teratoma. The diagnostic and management challenges posed by this huge ovarian cyst were discussed in the light of the literature.

  20. Huge mediastinal liposarcoma resected by clamshell thoracotomy: a case report. (United States)

    Toda, Michihito; Izumi, Nobuhiro; Tsukioka, Takuma; Komatsu, Hiroaki; Okada, Satoshi; Hara, Kantaro; Ito, Ryuichi; Shibata, Toshihiko; Nishiyama, Noritoshi


    Liposarcoma is the single most common soft tissue sarcoma. Because mediastinal liposarcomas often grow rapidly and frequently recur locally despite adjuvant chemotherapy and radiotherapy, they require complete excision. Therefore, the feasibility of achieving complete surgical excision must be carefully considered. We here report a case of a huge mediastinal liposarcoma resected via clamshell thoracotomy. A 64-year-old man presented with dyspnea on effort. Cardiomegaly had been diagnosed 6 years previously, but had been left untreated. A computed tomography scan showed a huge (36 cm diameter) anterior mediastinal tumor expanding into the pleural cavities bilaterally. The tumor comprised mostly fatty tissue but contained two solid areas. Echo-guided needle biopsies were performed and a diagnosis of an atypical lipomatous tumor was established by pathological examination of the biopsy samples. Surgical resection was performed via a clamshell incision, enabling en bloc resection of this huge tumor. Although there was no invasion of surrounding organs, the left brachiocephalic vein was resected because it was circumferentially surrounded by tumor and could not be preserved. The tumor weighed 3500 g. Pathologic examination of the resected tumor resulted in a diagnosis of a biphasic tumor comprising dedifferentiated liposarcoma and non-adipocytic sarcoma with necrotic areas. The patient remains free of recurrent tumor 20 months postoperatively. Clamshell incision provides an excellent surgical field and can be performed safely in patients with huge mediastinal liposarcomas.

  1. Huge uterine-cervical diverticulum mimicking as a cyst

    Directory of Open Access Journals (Sweden)

    S Chufal


    Full Text Available Here we report an incidental huge uterine-cervical diverticulum from a total abdominal hysterectomy specimen in a perimenopausal woman who presented with acute abdominal pain. The diverticulum was mimicking with various cysts present in the lateral side of the female genital tract. Histopathological examination confirmed this to be a cervical diverticulum with communication to uterine cavity through two different openings. They can attain huge size if left ignored for long duration and present a diagnostic challenge to clinicians, radiologists, as well as pathologists because of its extreme rarity. Therefore, diverticula should also be included as a differential diagnosis. Its histopathological confirmation also highlights that diverticula can present as an acute abdomen, requiring early diagnosis with appropriate timely intervention. Immunohistochemistry CD 10 has also been used to differentiate it from a mesonephric cyst.

  2. Huge uterine-cervical diverticulum mimicking as a cyst. (United States)

    Chufal, S; Thapliyal, Naveen; Gupta, Manoj; Pangtey, Nirmal


    Here we report an incidental huge uterine-cervical diverticulum from a total abdominal hysterectomy specimen in a perimenopausal woman who presented with acute abdominal pain. The diverticulum was mimicking with various cysts present in the lateral side of the female genital tract. Histopathological examination confirmed this to be a cervical diverticulum with communication to uterine cavity through two different openings. They can attain huge size if left ignored for long duration and present a diagnostic challenge to clinicians, radiologists, as well as pathologists because of its extreme rarity. Therefore, diverticula should also be included as a differential diagnosis. Its histopathological confirmation also highlights that diverticula can present as an acute abdomen, requiring early diagnosis with appropriate timely intervention. Immunohistochemistry CD 10 has also been used to differentiate it from a mesonephric cyst.

  3. A case of huge primary liposarcoma in the liver

    Institute of Scientific and Technical Information of China (English)

    Liang-Mou Kuo; Hong-Shiue Chou; Kun-Ming Chan; Ming-Chin Yu; Wei-Chen Lee


    Primary liver liposarcoma is a rare disease. Because of its rarity, the knowledge of the clinical course, management, and prognosis of primary liver liposarcoma are all limited for clinicians. A 61-year-old female patient who suffered from a huge primary liposarcoma in the central portion of the liver had the clinical presentations of fever, nausea, vomiting, jaundice, and body weight loss.The huge tumor was resected successfully. However,the tumor recurred repeatedly and she had repeated hepatectomies to remove the tumor. Thetumor became aggravating after repeated surgeries. Eventually, the patient had cervical spinal metastasis of liposarcoma and she survived for 26 months after liver liposarcoma was diagnosed. Although the tumor may become aggravating after repeated surgeries, repeated hepatectomies are still the best policy to achieve a long-term survival for the patients.

  4. Black Hole Firewalls Require Huge Energy of Measurement

    CERN Document Server

    Hotta, Masahiro; Funo, Ken


    The unitary moving mirror model is one of the best quantum systems for checking the reasoning of the firewall paradox in quantum black holes. The reasoning of Almheiri et al. inevitably raises a firewall paradox in the model. We resolve this paradox from the viewpoint of the energy cost of quantum measurements. No firewall with a deadly, huge energy flux appears, as long as the energy for the measurement is much smaller than the ultraviolet cutoff scale.

  5. Severe microphthalmos with cyst and unusually huge dermolipoma. (United States)

    Li, Weidong; Zhang, Ping; Chen, Qiwen; Ye, Xuelian; Li, Jianqun; Yan, Jianhua


    The purpose of this study was to report an unusual case of severe microphthalmos, together with an orbital cyst and huge ocular surface dermolipoma. This is a clinical report relating clinical features as well as imaging and histopathologic findings, along with surgical management of the patient. A 5-month-old Chinese male infant was referred, with 2 large masses in the left eye that were present since birth. Ocular examination results revealed a complete absence of any eye structures in the left orbit. In its place were 2 large masses between the left upper and lower palpebral fissure. One was a 3 × 3 × 2.5-cm spherical red tumor with a smooth surface. The other was a large solid spherical tumor, 4 × 4 × 5 cm, covered with normal skin located in the temporal region and attached to the red mass by a pedicle. Orbital magnetic resonance imaging examination findings confirmed that no eye structures were present in the left orbit. However, a cystic lesion was found in the left orbit, with a low signal on T1-weighted imaging and high signal on T2-weighted imaging, and another huge spherical heterogeneous mass was located "outside" the left orbit. Anterior orbitotomy by conjunctival incision was performed under general anesthesia. A spherical cystic mass of 1.5 × 1.5 × 1.6 cm, a small eye of 0.7 × 0.7 × 0.6 cm, and a huge dermolipoma were removed completely. Pathologic examination results confirmed the diagnosis of severe microphthalmos, together with orbital dermoid cyst and dermolipoma. This rare case demonstrates that severe microphthalmos with a cyst may be completely covered by conjunctiva and associated with an unusually huge dermolipoma.

  6. Huge plastic bezoar: a rare cause of gastrointestinal obstruction. (United States)

    Yaka, Mbarek; Ehirchiou, Abdelkader; Alkandry, Tariq Tajdin Sifeddine; Sair, Khalid


    Bezoars are rare causes of gastrointestinal obstruction. Basically, they are of four types: trichobezoars, phytobezoars, pharmacobezoars, and lactobezoars. Some rare types of bezoars are also known. In this article a unique case of plastic bezoars is presented. We describe a girl aged 14 years who ingested large amounts of plastic material used for knitting chairs and charpoys. The conglomerate of plastic threads, entrapped food material and other debris, formed a huge mass occupying the whole stomach and extended into small bowel.

  7. A Huge Cystic Retroperitoneal Lymphangioma Presenting with Back Pain (United States)

    Kubachev, Kubach; Abdullaev, Elbrus; Babyshin, Valentin; Neronov, Dmitriy; Abdullaev, Abakar


    Retroperitoneal lymphangioma is a rare location and type of benign abdominal tumors. The clinical presentation of this rare disease is nonspecific, ranging from abdominal distention to sepsis. Here we present a 73-year-old female patient with 3-month history of back pain. USG and CT revealed a huge cystic mass which was surgically excised and appeared to be lymphangioma on histopathology. PMID:27843456

  8. Huge Left Atrium Accompanied by Normally Functioning Prosthetic Valve. (United States)

    Sabzi, Feridoun


    Giant left atria are defined as those measuring larger than 8 cm and are typically found in patients who have rheumatic mitral valve disease with severe regurgitation. Enlargement of the left atrium may create compression of the surrounding structures such as the esophagus, pulmonary veins, respiratory tract, lung, inferior vena cava, recurrent laryngeal nerve, and thoracic vertebrae and lead to dysphagia, respiratory dysfunction, peripheral edema, hoarse voice, or back pain. However, a huge left atrium is usually associated with rheumatic mitral valve disease but is very rare in a normally functioning prosthetic mitral valve, as was the case in our patient. A 46-year-old woman with a past medical history of mitral valve replacement and chronic atrial fibrillation was admitted to our hospital with a chief complaint of cough and shortness of breath, worsened in the last month. Physical examination showed elevated jugular venous pressure, respiratory distress, cardiac cachexia, heart failure, hepatomegaly, and severe edema in the legs. Chest radiography revealed an inconceivably huge cardiac sell-out. Transthoracic echocardiography demonstrated a huge left atrium, associated with thrombosis, and normal function of the prosthetic mitral valve. Cardiac surgery with left atrial exploration for the extraction of the huge thrombosis and De Vega annuloplasty for tricuspid regurgitation were carried out. The postoperative course was eventful due to right ventricular failure and low cardiac output syndrome; and after two days, the patient expired with multiple organ failure. Thorough literature review showed that our case was the largest left atrium (20 × 22 cm) reported thus far in adults with a normal prosthetic mitral valve function.

  9. Huge Left Atrium Accompanied by Normally Function- ing Prosthetic Valve

    Directory of Open Access Journals (Sweden)

    Feridoun Sabzi


    Full Text Available Giant left atria are defined as those measuring larger than 8 cm and are typically found in patients who have rheumatic mitral valve disease with severe regurgitation. Enlargement of the left atrium may create compression of the surrounding structures such as the esophagus, pulmonary veins, respiratory tract, lung, inferior vena cava, recurrent laryngeal nerve, and thoracic vertebrae and lead to dysphagia, respiratory dysfunction, peripheral edema, hoarse voice, or back pain. However, a huge left atrium is usually associated with rheumatic mitral valve disease but is very rare in a normally functioning prosthetic mitral valve, as was the case in our patient. A 46-year-old woman with a past medical history of mitral valve replacement and chronic atrial fibrillation was admitted to our hospital with a chief complaint of cough and shortness of breath, worsened in the last month. Physical examination showed elevated jugular venous pressure, respiratory distress, cardiac cachexia, heart failure, hepatomegaly, and severe edema in the legs. Chest radiography revealed an inconceivably huge cardiac sell-out. Transthoracic echocardiography demonstrated a huge left atrium, associated with thrombosis, and normal function of the prosthetic mitral valve. Cardiac surgery with left atrial exploration for the extraction of the huge thrombosis and De Vega annuloplasty for tricuspid regurgitation were carried out. The postoperative course was eventful due to right ventricular failure and low cardiac output syndrome; and after two days, the patient expired with multiple organ failure. Thorough literature review showed that our case was the largest left atrium (20 × 22 cm reported thus far in adults with a normal prosthetic mitral valve function.

  10. Huge Nevus Lipomatosus Cutaneous Superficialis on Back: An Unusual Presentation. (United States)

    Das, Dipti; Das, Anupam; Bandyopadhyay, Debabrata; Kumar, Dhiraj


    Nevus lipomatosus cutaneous superficialis (NLCS) is a benign dermatosis, histologically characterized by the presence of mature ectopic adipocytes in the dermis. We hereby report a case of a 10-year-old boy who presented with multiple huge swellings on the scapular regions and lower back. The lesions were surmounted by small papules, along with peau-d orange appearance at places. Histology showed features consistent with NLCS. The case is being reported for the unusual clinical presentation.

  11. Huge nevus lipomatosus cutaneous superficialis on back: An unusual presentation

    Directory of Open Access Journals (Sweden)

    Dipti Das


    Full Text Available Nevus lipomatosus cutaneous superficialis (NLCS is a benign dermatosis, histologically characterized by the presence of mature ectopic adipocytes in the dermis. We hereby report a case of a 10-year-old boy who presented with multiple huge swellings on the scapular regions and lower back. The lesions were surmounted by small papules, along with peau-d orange appearance at places. Histology showed features consistent with NLCS. The case is being reported for the unusual clinical presentation.

  12. Huge Intravascular Tumor Extending to the Heart: Leiomyomatosis

    Directory of Open Access Journals (Sweden)

    Suat Doganci


    Full Text Available Intravenous leiomyomatosis (IVL is a rare neoplasm characterized by histologically benign-looking smooth muscle cell tumor mass, which is growing within the intrauterine and extrauterine venous system. In this report we aimed to present an unusual case of IVL, which is originating from iliac vein and extended throughout to right cardiac chambers. A 49-year-old female patient, who was treated with warfarin sodium due to right iliac vein thrombosis, was admitted to our department with intermittent dyspnea, palpitation, and dizziness. Physical examination was almost normal except bilateral pretibial edema. On magnetic resonance venography, there was an intravenous mass, which is originated from right internal iliac vein and extended into the inferior vena cava. Transthoracic echocardiography and transesophageal echocardiography revealed a huge mass extending from the inferior vena cava through the right atrium, with obvious venous occlusion. Thoracic, abdominal, and pelvic MR showed an intravascular mass, which is concordant with leiomyomatosis. Surgery was performed through median sternotomy. A huge mass with 25-cm length and 186-gr weight was excised through right atrial oblique incision, on beating heart with cardiopulmonary bypass. Histopathologic assessment was compatible with IVL. Exact strategy for the surgical treatment of IVL is still controversial. We used one-stage approach, with complete resection of a huge IVL extending from right atrium to right iliac vein. In such cases, high recurrence rate is a significant problem; therefore it should be kept in mind.

  13. Multimodality treatment with radiotherapy for huge hepatocellular carcinoma. (United States)

    Han, Hee Ji; Kim, Mi Sun; Cha, Jihye; Choi, Jin Sub; Han, Kwang Hyub; Seong, Jinsil


    For huge hepatocellular carcinoma (HCC), therapeutic decisions have varied from local therapy to systemic therapy, with radiotherapy (RT) playing only a palliative role. In this study, we investigated whether multimodality treatment involving RT could be effective in huge HCC. This study was performed in 116 patients with HCC >10 cm. The number of patients in stage II, III and IV was 12, 54 and 50, respectively. RT was given as a combined modality in most patients. The median dose was 45 Gy, with 1.8 Gy per fraction. The median overall survival (OS) and progression-free survival (PFS) were 14.8 and 6.5 months, respectively. The median infield PFS was not reached. Infield failure, outfield intrahepatic and extrahepatic failure were observed in 8.6, 18.1, and 12.1% of patients, respectively. For OS and PFS, number of tumors, initial alpha-fetoprotein (AFP) level, treatment response, percent AFP decrement, and hepatic resection were significant prognostic factors. Tumor characteristics and treatment response were significantly different between long-term survivors and the other patients. Although huge HCC presents an aggressive clinical course, multimodality approaches involving RT can offer an opportunity for prolonged survival. © 2014 S. Karger AG, Basel.

  14. Huge Intravascular Tumor Extending to the Heart: Leiomyomatosis. (United States)

    Doganci, Suat; Kaya, Erkan; Kadan, Murat; Karabacak, Kubilay; Erol, Gökhan; Demirkilic, Ufuk


    Intravenous leiomyomatosis (IVL) is a rare neoplasm characterized by histologically benign-looking smooth muscle cell tumor mass, which is growing within the intrauterine and extrauterine venous system. In this report we aimed to present an unusual case of IVL, which is originating from iliac vein and extended throughout to right cardiac chambers. A 49-year-old female patient, who was treated with warfarin sodium due to right iliac vein thrombosis, was admitted to our department with intermittent dyspnea, palpitation, and dizziness. Physical examination was almost normal except bilateral pretibial edema. On magnetic resonance venography, there was an intravenous mass, which is originated from right internal iliac vein and extended into the inferior vena cava. Transthoracic echocardiography and transesophageal echocardiography revealed a huge mass extending from the inferior vena cava through the right atrium, with obvious venous occlusion. Thoracic, abdominal, and pelvic MR showed an intravascular mass, which is concordant with leiomyomatosis. Surgery was performed through median sternotomy. A huge mass with 25-cm length and 186-gr weight was excised through right atrial oblique incision, on beating heart with cardiopulmonary bypass. Histopathologic assessment was compatible with IVL. Exact strategy for the surgical treatment of IVL is still controversial. We used one-stage approach, with complete resection of a huge IVL extending from right atrium to right iliac vein. In such cases, high recurrence rate is a significant problem; therefore it should be kept in mind.

  15. Phase slips in superconducting weak links

    Energy Technology Data Exchange (ETDEWEB)

    Kimmel, Gregory; Glatz, Andreas; Aranson, Igor S.


    Superconducting vortices and phase slips are primary mechanisms of dissipation in superconducting, superfluid, and cold-atom systems. While the dynamics of vortices is fairly well described, phase slips occurring in quasi-one- dimensional superconducting wires still elude understanding. The main reason is that phase slips are strongly nonlinear time-dependent phenomena that cannot be cast in terms of small perturbations of the superconducting state. Here we study phase slips occurring in superconducting weak links. Thanks to partial suppression of superconductivity in weak links, we employ a weakly nonlinear approximation for dynamic phase slips. This approximation is not valid for homogeneous superconducting wires and slabs. Using the numerical solution of the time-dependent Ginzburg-Landau equation and bifurcation analysis of stationary solutions, we show that the onset of phase slips occurs via an infinite period bifurcation, which is manifested in a specific voltage-current dependence. Our analytical results are in good agreement with simulations.

  16. Learning to predict slip for ground robots (United States)

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


    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.

  17. Slip resistance testing - Zones of uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, R.


    This paper considers recent and current potential developments in the international standardisation of slip resistance. It identifies some limitations of the wet barefoot ramp test, such that changes should be made if it is to be more widely used. It also identifies some limitations of the new European SlipSTD Publicly Available Specification, such as insufficient allowance for the deterioration of slip resistance as tiles inevitably wear. (Author) 22 refs.

  18. Large Slip Length over a Nanopatterned Surface

    Institute of Scientific and Technical Information of China (English)

    LI Ding; DI Qin-Feng; LI Jing-Yuan; QIAN Yue-Hong; FANG Hai-Ping


    A thermodynamic method is employed to analyse the slip length of hydrophobic nanopatterned surface.The maximal slip lengths with respect to the hydrophobicity of the nanopatterned surface are computed.It is found that the slip length reaches more than 50μm if the nanopatterned surfaces have a contact angle larger than 160°.Such results are expected to find extensive applications in micro-channels and helpful to understand recent experimental observations of the slippage of nanopatterned surfaces.

  19. Cycle slipping in phase synchronization systems (United States)

    Yang, Ying; Huang, Lin


    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.

  20. Observation of slip flow in thermophoresis. (United States)

    Weinert, Franz M; Braun, Dieter


    Two differing theories aim to describe fluidic thermophoresis, the movement of particles along a temperature gradient. While thermodynamic approaches rely on local equilibrium, hydrodynamic descriptions assume a quasi-slip-flow boundary condition at the particle's surface. Evidence for slip flow is presented for the case of thermal gradients exceeding (aS_(T)(-1) with particle radius a and Soret coefficient S_(T). Thermophoretic slip flow at spheres near a surface attracts or repels tracer particles perpendicular to the thermal gradient. Moreover, particles mutually attract and form colloidal crystals. Fluid dynamic slip explains the latter quantitatively.

  1. Slip resistance of non-slip socks--an accelerometer-based approach. (United States)

    Hübscher, Markus; Thiel, Christian; Schmidt, Jens; Bach, Matthias; Banzer, Winfried; Vogt, Lutz


    The present study investigated the relative slip resistance of commercially available non-slip socks during gait. Twenty-four healthy subjects (29.3±10.4 years) participated in the study. Each subject completed 4 different test conditions (barefoot, non-slip socks, conventional socks, backless slippers) in a randomized, balanced order. The slip resistance was estimated by measuring the heel deceleration time using a heel-mounted accelerometer. Repeated measures ANOVA and post hoc paired-sample t-test with Bonferroni correction were used for statistical analysis. Compared to barefoot walking absolute deceleration times [ms] were significantly increased when wearing conventional socks or slippers. No significant differences were observed between the barefoot and non-slip socks conditions. The present study shows that non-slip socks improved slip-resistance during gait when compared to conventional socks and slippers. Future investigations should verify the present findings in hospital populations prone to slip-related falls.

  2. Analyzing huge pathology images with open source software. (United States)

    Deroulers, Christophe; Ameisen, David; Badoual, Mathilde; Gerin, Chloé; Granier, Alexandre; Lartaud, Marc


    Digital pathology images are increasingly used both for diagnosis and research, because slide scanners are nowadays broadly available and because the quantitative study of these images yields new insights in systems biology. However, such virtual slides build up a technical challenge since the images occupy often several gigabytes and cannot be fully opened in a computer's memory. Moreover, there is no standard format. Therefore, most common open source tools such as ImageJ fail at treating them, and the others require expensive hardware while still being prohibitively slow. We have developed several cross-platform open source software tools to overcome these limitations. The NDPITools provide a way to transform microscopy images initially in the loosely supported NDPI format into one or several standard TIFF files, and to create mosaics (division of huge images into small ones, with or without overlap) in various TIFF and JPEG formats. They can be driven through ImageJ plugins. The LargeTIFFTools achieve similar functionality for huge TIFF images which do not fit into RAM. We test the performance of these tools on several digital slides and compare them, when applicable, to standard software. A statistical study of the cells in a tissue sample from an oligodendroglioma was performed on an average laptop computer to demonstrate the efficiency of the tools. Our open source software enables dealing with huge images with standard software on average computers. They are cross-platform, independent of proprietary libraries and very modular, allowing them to be used in other open source projects. They have excellent performance in terms of execution speed and RAM requirements. They open promising perspectives both to the clinician who wants to study a single slide and to the research team or data centre who do image analysis of many slides on a computer cluster. The virtual slide(s) for this article can be found here


    Directory of Open Access Journals (Sweden)



    Full Text Available Due to the tremendous growth of data and large databases, efficient extraction of required data has become a challenging task. This paper propose a novel approach for knowledge discovery from huge unlabeled temporal databases by employing a combination of HMM and K-means technique. We propose to recursively divide the entire database into clusters having similar characteristics, this process is repeated until we get the cluster’s where no further diversification is possible. Thereafter, the clusters are labeled for knowledge extraction for various purposes.

  4. A young woman with a huge paratubal cyst

    Directory of Open Access Journals (Sweden)

    Ceren Golbasi


    Full Text Available Paratubal cysts are asymptomatic embryological remnants. These cysts are usually diagnosed during adolescence and reproductive age. In general, their sizes are small but can be complicated by rupture, torsion, or hemorrhage. Paratubal cysts are often discovered fortuitously on routine ultrasound examination. We report a 19-year-old female patient who presented with irregular menses and abdominal pain. Ultrasound examination revealed a huge cystic mass at the right adnexial area. The diagnosis was confirmed as paratubal cyst during laporotomy and, hence, cystectomy and right salpingectomy were performed. [Cukurova Med J 2016; 41(3.000: 573-576

  5. Modeling huge sound sources in a room acoustical calculation program

    DEFF Research Database (Denmark)

    Christensen, Claus Lynge


    A room acoustical model capable of modeling point sources, line sources, and surface sources is presented. Line and surface sources are modeled using a special ray-tracing algorithm detecting the radiation pattern of the surfaces of the room. Point sources are modeled using a hybrid calculation...... method combining this ray-tracing method with image source modeling. With these three source types it is possible to model huge and complex sound sources in industrial environments. Compared to a calculation with only point sources, the use of extended sound sources is shown to improve the agreement...

  6. A huge renal capsular leiomyoma mimicking retroperitoneal sarcoma

    Directory of Open Access Journals (Sweden)

    Lal Anupam


    Full Text Available A huge left renal capsular leiomyoma mimicking retroperitoneal sarcoma presented in a patient as an abdominal mass. Computed tomography displayed a large heterogeneous retro-peritoneal mass in the left side of the abdomen with inferior and medial displacement as well as loss of fat plane with the left kidney. Surgical exploration revealed a capsulated mass that was tightly adherent to the left kidney; therefore, total tumor resection with radical left nephrectomy was performed. Histopathology ultimately confirmed the benign nature of the mass. This is the largest leiomyoma reported in literature to the best of our knowledge.

  7. Huge pyometra in a postmenopausal age: a diagnostic dilemma

    Directory of Open Access Journals (Sweden)

    Pramila Yadav


    Full Text Available Pyometra in postmenopausal women is an extremely rare disease that hardly responds to the usual treatment of antibiotics therapy. Our case presented as a postmenopausal woman with a huge pyometra. Pyometra drainage was done with great difficulty after a blind biopsy. Endometrial and cervical biopsy followed by endometrial curettage was done. An intrauterine foley's catheter was kept for seven days and Histopathological report was suggestive of squamous cell carcinoma of cervix. [Int J Reprod Contracept Obstet Gynecol 2015; 4(5.000: 1549-1551

  8. A Brief Analysis on Slips of Tongue

    Institute of Scientific and Technical Information of China (English)



    The phenomenon of slips of tongue is very common in our daily life.And it is closely related to some psychological reasons.This paper aims to introduce the research about this phenomenon, to present the types of slips of tongue and some analysis on it.

  9. Slip versus Friction : Modifying the Navier condition (United States)

    Kotsalis, Evangelos; Walther, Jens; Koumoutsakos, Petros


    The modeling of fluid-solid interfaces remains one of the key challenges in fluid mechanics. The prevailing model, attributed to Navier, defines the fluid ``slip'' velocity as proportional to the wall shear and a parameter defined as the slip length. Several works have in turn proposed models for this slip length but no universal model for the slip velocity has been accepted. We present results from large scale molecular dynamics simulations of canonical flow problems, indicating, that the inadequacy of this classic model, stems from not properly accounting for the pressure field. We propose and validate a new model, based on the fundamental observation that the finite ``slip'' velocity is a result of an imbalance between fluid and solid intermolecular forces. An excess force on the fluid elements will lead to their acceleration which in turn may result in a slip velocity at the interface. We formulate the slip velocity in terms of fluid-solid friction Ff and propose a generalized boundary condition: Ff= Fs+ Fp= λuus+ λpp where p denotes the pressure, and λuand λp the viscous and static friction coefficients, for which universal constants are presented. We demonstrate that the present model can overcome difficulties encountered by the classical slip model in canonical flow configurations.

  10. Microstructure and Slip Character in Titanium Alloys

    Directory of Open Access Journals (Sweden)

    D. Banerjee


    Full Text Available Influence of microstructures in titanium alloys on the basic parameters of deformation behaviour such as slip character, slip length and slip intensity have been explored. Commercial titanium alloys contain the hexagonal close packed (alpha and body centred cubic (bita phases. Slip in these individual phases is shown to be dependent on the nature of alloying elements through their effect on phase stability as related to decomposition into ordered or w structures. When alpha and bita coexist, their relative crystallographic orientations, size, shape and volume fraction, control the nature of slip. For a given composition, structure may be manipulated through appropriate thermomechanical treatment to obtain the desired deformation behaviour and therefore fracture mode.

  11. Impact of thermal radiation on MHD slip flow of a ferrofluid over a non-isothermal wedge (United States)

    Rashad, A. M.


    This article is concerned with the problem of magnetohydrodynamic (MHD) mixed convection flow of Cobalt-kerosene ferrofluid adjacent a non-isothermal wedge under the influence of thermal radiation and partial slip. Such type of problems are posed by electric generators and biomedical enforcement. The governing equations are solved using the Thomas algorithm with finite-difference type and solutions for a wide range of magnet parameter are presented. It is found that local Nusselt number manifests a considerable diminishing for magnetic parameter and magnifies intensively in case of slip factor, thermal radiation and surface temperature parameters. Further, the skin friction coefficient visualizes a sufficient enhancement for the parameters thermal radiation, surface temperature and magnetic field, but a huge reduction is recorded by promoting the slip factor.

  12. Slow slip generated by dehydration reaction coupled with slip-induced dilatancy and thermal pressurization (United States)

    Yamashita, Teruo; Schubnel, Alexandre


    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.

  13. Errors in Seismic Hazard Assessment are Creating Huge Human Losses (United States)

    Bela, J.


    The current practice of representing earthquake hazards to the public based upon their perceived likelihood or probability of occurrence is proven now by the global record of actual earthquakes to be not only erroneous and unreliable, but also too deadly! Earthquake occurrence is sporadic and therefore assumptions of earthquake frequency and return-period are both not only misleading, but also categorically false. More than 700,000 people have now lost their lives (2000-2011), wherein 11 of the World's Deadliest Earthquakes have occurred in locations where probability-based seismic hazard assessments had predicted only low seismic low hazard. Unless seismic hazard assessment and the setting of minimum earthquake design safety standards for buildings and bridges are based on a more realistic deterministic recognition of "what can happen" rather than on what mathematical models suggest is "most likely to happen" such future huge human losses can only be expected to continue! The actual earthquake events that did occur were at or near the maximum potential-size event that either already had occurred in the past; or were geologically known to be possible. Haiti's M7 earthquake, 2010 (with > 222,000 fatalities) meant the dead could not even be buried with dignity. Japan's catastrophic Tohoku earthquake, 2011; a M9 Megathrust earthquake, unleashed a tsunami that not only obliterated coastal communities along the northern Japanese coast, but also claimed > 20,000 lives. This tsunami flooded nuclear reactors at Fukushima, causing 4 explosions and 3 reactors to melt down. But while this history of huge human losses due to erroneous and misleading seismic hazard estimates, despite its wrenching pain, cannot be unlived; if faced with courage and a more realistic deterministic estimate of "what is possible", it need not be lived again. An objective testing of the results of global probability based seismic hazard maps against real occurrences has never been done by the

  14. Distributed and parallel approach for handle and perform huge datasets (United States)

    Konopko, Joanna


    Big Data refers to the dynamic, large and disparate volumes of data comes from many different sources (tools, machines, sensors, mobile devices) uncorrelated with each others. It requires new, innovative and scalable technology to collect, host and analytically process the vast amount of data. Proper architecture of the system that perform huge data sets is needed. In this paper, the comparison of distributed and parallel system architecture is presented on the example of MapReduce (MR) Hadoop platform and parallel database platform (DBMS). This paper also analyzes the problem of performing and handling valuable information from petabytes of data. The both paradigms: MapReduce and parallel DBMS are described and compared. The hybrid architecture approach is also proposed and could be used to solve the analyzed problem of storing and processing Big Data.

  15. Anaethetic management of a neonate with huge cystic hygroma.

    Directory of Open Access Journals (Sweden)

    Bindi Palkhiwala


    Full Text Available We discuss here the case of a 7 day old neonate with huge cystic hygroma on the left side of the neck invading the major vessels of neck, facial nerve, strap muscles and sternocleidomastoid. Anasethtic implications in this case were maintaining airway patency after induction, difficult intubation, risk perioperative dislodgement of tube and judgement of proper time for extubation. Following gaseous induction and adequate mask ventilation, patient was intubated with muscle relaxant. peroperatively to avoid accidental extubation, we choose to manually hold the ET tube after fixing it. At the end of relatively uneventful surgery, we could extubate the patient in OT. patient was shifted to NICU for observation. Post operatively on 3rd day, facial palsy was observed. Ptient was discharged on 21st day.

  16. Huge Intracanal lumbar Disc Herniation: a Review of Four Cases

    Directory of Open Access Journals (Sweden)

    Farzad Omidi-Kashani


    Full Text Available Lumbar disc herniation (LDH is the most common cause of sciatica and only in about 10% of the affected patients, surgical intervention is necessary. The side of the patient (the side of most prominent clinical complaints is usually consistent with the side of imaging (the side with most prominent disc herniation on imaging scans. In this case series, we presented our experience in four cases with huge intracanal LDH that a mismatch between the patient’s side and the imaging’s side was present. In these cases, for deciding to do the operation, the physicians need to rely more on clinical findings, but for deciding the side of discectomy, imaging characteristic (imaging side may be a more important criterion.

  17. A parallel solver for huge dense linear systems (United States)

    Badia, J. M.; Movilla, J. L.; Climente, J. I.; Castillo, M.; Marqués, M.; Mayo, R.; Quintana-Ortí, E. S.; Planelles, J.


    HDSS (Huge Dense Linear System Solver) is a Fortran Application Programming Interface (API) to facilitate the parallel solution of very large dense systems to scientists and engineers. The API makes use of parallelism to yield an efficient solution of the systems on a wide range of parallel platforms, from clusters of processors to massively parallel multiprocessors. It exploits out-of-core strategies to leverage the secondary memory in order to solve huge linear systems O(100.000). The API is based on the parallel linear algebra library PLAPACK, and on its Out-Of-Core (OOC) extension POOCLAPACK. Both PLAPACK and POOCLAPACK use the Message Passing Interface (MPI) as the communication layer and BLAS to perform the local matrix operations. The API provides a friendly interface to the users, hiding almost all the technical aspects related to the parallel execution of the code and the use of the secondary memory to solve the systems. In particular, the API can automatically select the best way to store and solve the systems, depending of the dimension of the system, the number of processes and the main memory of the platform. Experimental results on several parallel platforms report high performance, reaching more than 1 TFLOP with 64 cores to solve a system with more than 200 000 equations and more than 10 000 right-hand side vectors. New version program summaryProgram title: Huge Dense System Solver (HDSS) Catalogue identifier: AEHU_v1_1 Program summary URL: Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, No. of lines in distributed program, including test data, etc.: 87 062 No. of bytes in distributed program, including test data, etc.: 1 069 110 Distribution format: tar.gz Programming language: Fortran90, C Computer: Parallel architectures: multiprocessors, computer clusters Operating system

  18. A huge glandular odontogenic cyst occurring at posterior mandible

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Gi Chung; Han, Won Jeong; Kim, Eun Kyung [Dankook University College of Medicine, Seoul (Korea, Republic of)


    The glandular odontogenic cyst is a rare lesion described in 1987. It generally occurs at anterior region of mandible in adults over the age of 40 and has a slight tendency to recur. Histopathologically, a cystic cavity lined by a nonkeratinized, stratified squamous, or cuboidal epithelium varying in thickness is found including a superficial layer with glandular or pseudoglandular structures. A 21-year-old male visited Dankook University Dental Hospital with a chief complaint of swelling of the left posterior mandible. Radiographically, a huge multilocular radiolucent lesion involving impacted 3rd molar at the posterior mandible was observed. Buccolingual cortical expansion with partial perforation of buccal cortical bone was also shown. Histopathologically, this lesion was lined by stratified squamous epithelium with glandular structures in areas of plaque-like thickening. The final diagnosis was made as a glandular odontogenic cyst.

  19. Does China's Huge External Surplus Imply an Undervalued Renminbi?

    Institute of Scientific and Technical Information of China (English)

    Anthony J. Makin


    A pegged exchange rate regime has been pivotal to China's export-led development strategy. However, its huge trade surpluses and massive build up of international reserves have been matched by large deficits for major trading partners, creating acute policy concerns abroad, especially in the USA. This paper provides a straightforward conceptual framework for interpreting the effect of China's exchange rate policy on its own trade balance and that of trading partners in the context of discrepant economic growth rates. It shows how pegging the exchange rate when output is outstripping expenditure induces China's trade surpluses and counterpart deficits for its trading partners. An important corollary is that given its strictly regulated capital account, China's persistently large surpluses imply a significantly undervalued renminbi, which should gradually become more flexible.

  20. Electrophoresis of particles with Navier velocity slip. (United States)

    Park, Hung Mok


    In the present investigation, it is found that the electrophoretic mobility of hydrophobic particles is affected not only by the zeta potential but also by the velocity slip at the particle surface. From a physicochemical viewpoint, zeta potential represents the surface charge properties and the slip coefficient indicates the hydrophobicity of the particle surface. Thus, it is necessary to separate the contribution of zeta potential from that of slip coefficient to the particle mobility, since zeta potential can be changed by varying the bulk ionic concentration while the slip coefficient can be modified by adjusting surfactant concentration. In the present investigation, a method is devised that allows a simultaneous estimation of zeta potential and slip coefficient of micro and nanoparticles using measurements of electrophoretic mobility at various bulk ionic concentrations. Employing a nonlinear curve-fitting technique and an analytic solution of electrophoresis for a particle with velocity slip, the present technique predicts both zeta potential and slip coefficient simultaneously with reasonable accuracy using the measured values of electrophoretic mobility at various bulk ionic concentrations.

  1. Dynamical Stability of Slip-stacking Particles

    CERN Document Server

    Eldred, Jeffrey


    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.

  2. Tsunami Hazards From Strike-Slip Earthquakes (United States)

    Legg, M. R.; Borrero, J. C.; Synolakis, C. E.


    Strike-slip faulting is often considered unfavorable for tsunami generation during large earthquakes. Although large strike-slip earthquakes triggering landslides and then generating substantial tsunamis are now recognized hazards, many continue to ignore the threat from submarine tectonic displacement during strike-slip earthquakes. Historical data record the occurrence of tsunamis from strike-slip earthquakes, for example, 1906 San Francisco, California, 1994 Mindoro, Philippines, and 1999 Izmit, Turkey. Recognizing that strike-slip fault zones are often curved and comprise numerous en echelon step-overs, we model tsunami generation from realistic strike-slip faulting scenarios. We find that tectonic seafloor uplift, at a restraining bend or"pop-up" structure, provides an efficient mechanism to generate destructive local tsunamis; likewise for subsidence at divergent pull-apart basin structures. Large earthquakes on complex strike-slip fault systems may involve both types of structures. The California Continental Borderland is a high-relief submarine part of the active Pacific-North America transform plate boundary. Natural harbors and bays created by long term vertical motion associated with strike-slip structural irregularities are now sites of burgeoning population and major coastal infrastructure. Significant local tsunamis generated by large strike-slip earthquakes pose a serious, and previously unrecognized threat. We model several restraining bend pop-up structures offshore southern California to quantify the local tsunami hazard. Maximum runup derived in our scenarios ranges from one to several meters, similar to runup observed from the 1994 Mindoro, Philippines, (M=7.1) earthquake. The runup pattern is highly variable, with local extremes along the coast. We only model the static displacement field for the strike-slip earthquake source; dynamic effects of moving large island or submerged banks laterally during strike-slip events remains to be examined

  3. Dynamical stability of slip-stacking particles

    Energy Technology Data Exchange (ETDEWEB)

    Eldred, Jeffrey; Zwaska, Robert


    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.

  4. Slow slip event at Kilauea Volcano (United States)

    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


    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].

  5. Dynamical Stability of Slip-stacking Particles

    Energy Technology Data Exchange (ETDEWEB)

    Eldred, Jeffrey [Fermilab; Zwaska, Robert [Fermilab


    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.

  6. Falls study: Proprioception, postural stability, and slips. (United States)

    Sohn, Jeehoon; Kim, Sukwon


    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.

  7. Action slips during whole-body vibration. (United States)

    Ishimatsu, Kazuma; Meland, Anders; Hansen, Tor Are S; Kåsin, Jan Ivar; Wagstaff, Anthony S


    Helicopter aircrew members engage in highly demanding cognitive tasks in an environment subject to whole-body vibration (WBV). Sometimes their actions may not be according to plan (e.g. action slips and lapses). This study used a Sustained Attention to Response Task (SART) to examine whether action slips were more frequent during exposure to WBV. Nineteen participants performed the SART in two blocks. In the WBV block participants were exposed to 17 Hz vertical WBV, which is typical of larger helicopter working environments. In the No-WBV block there was no WBV. There were more responses to the rare no-go digit 3 (i.e. action slips) in the WBV block, and participants responded faster in the WBV block. These results suggest that WBV influences response inhibition, and can induce impulsive responding. WBV may increase the likelihood of action slips, mainly due to failure of response inhibition.

  8. Deterministic phase slips in mesoscopic superconducting rings (United States)

    Petković, I.; Lollo, A.; Glazman, L. I.; Harris, J. G. E.


    The properties of one-dimensional superconductors are strongly influenced by topological fluctuations of the order parameter, known as phase slips, which cause the decay of persistent current in superconducting rings and the appearance of resistance in superconducting wires. Despite extensive work, quantitative studies of phase slips have been limited by uncertainty regarding the order parameter's free-energy landscape. Here we show detailed agreement between measurements of the persistent current in isolated flux-biased rings and Ginzburg-Landau theory over a wide range of temperature, magnetic field and ring size; this agreement provides a quantitative picture of the free-energy landscape. We also demonstrate that phase slips occur deterministically as the barrier separating two competing order parameter configurations vanishes. These results will enable studies of quantum and thermal phase slips in a well-characterized system and will provide access to outstanding questions regarding the nature of one-dimensional superconductivity.

  9. The slipping rib syndrome in children. (United States)

    Saltzman, D A; Schmitz, M L; Smith, S D; Wagner, C W; Jackson, R J; Harp, S


    The slipping rib syndrome is an infrequent cause of thoracic and upper abdominal pain and is thought to arise from the inadequacy or rupture of the interchondral fibrous attachments of the anterior ribs. This disruption allows the costal cartilage tips to sublux, impinging on the intercostal nerves. Children with this entity are seldom described in the literature. We present a retrospective review of 12 children and young adults with slipping rib syndrome and a systematic approach for evaluation and treatment.

  10. 以一敌百Slip-on

    Institute of Scientific and Technical Information of China (English)



    在运动鞋爆红的当下,一种不系带的Slip-on Sneakers成为了时尚人士的必备单品。Slip-on Sneakers就是把脚放进去即可的休闲鞋,由于穿脱方便,有了一个可爱的别名——"一脚蹬"。

  11. Phase Slips in Topological Superconductor Wire Devices (United States)

    Goldberg, Samuel; Bergman, Doron; Pekker, David; Refael, Gil


    We make a detailed study of phase slips in topological superconducting wires and devices based on topological wires. We begin by investigating a device composed of a topological superconducting wire connected to a non-topological wire (T-S). In the T-segment only slips of the phase by multiples of 4π are allowed, while in the S-segment slips by 2π are also allowed. We show that near the interface, 2π phase slips are also allowed and we comment on the consequences of such phase slips for the Aharonov-Casher effect. We also consider an implementation of a q-bit consisting of a T-S-T device, where the quantum information is stored in the parity of the two topological segments via the four Majorana modes. We show that the central S-segment of this type of device can support 2π phase-slips which result in the decoherence of the q-bit.

  12. Late Intervention-Related Complication - A Huge Subepicardial Hematoma. (United States)

    Ko, Po-Yen; Chang, Chih-Ping; Yang, Chen-Chia; Lin, Jen-Jyh


    A 75-year-old man had a history of triple vessel coronary artery disease. In August 2009, he had undergone successful percutaneous coronary intervention to the left circumflex coronary artery (LCX) for management of an in-stent restenosis (ISR) lesion. However, in September 2010, he began experiencing recurrent episodes of exertional chest pain. Chest radiography showed the left cardiac border bulging upwards. Transthoracic echocardiography and chest computed tomography revealed a huge oval mass of about 10.4 cm × 7.9 cm × 8.6 cm, which showed calcification and was obliterating the LCX. Subsequent coronary angiography revealed significant instent restenosis, with extravasation of a small amount of contrast material at the stent location, suggesting that the coronary artery had ruptured. We implanted a polytetrafluoroethylene-covered stent to seal the coronary perforation and to release the occlusion. The patient was symptom-free and had an uneventful outcome until the 1-year follow up. Coronary artery perforation; Covered stent; Hematoma.

  13. A huge posteromedial mediastinal cyst complicated with vertebral dislodgment

    Directory of Open Access Journals (Sweden)

    Manoussaridis Jordan T


    Full Text Available Abstract Background Mediastinal cysts compromise almost 20% of all mediastinal masses with bronchogenic subtype accounting for 60% of all cystic lesions. Although compression of adjoining soft tissues is usual, spinal complications and neurological symptoms are outmost rare and tend to characterize almost exclusively the neuroenteric cysts. Case presentation A young patient with intermittent, dull pain in his back and free medical history presented in the orthopaedic department of our hospital. There, the initial clinical and radiologic evaluation revealed a mediastinal mass and the patient was referred to the thoracic surgery department for further exploration. The following computed tomography (CT and magnetic resonance imaging (MRI shown a huge mediastinal cyst compressing the T4-T6 vertebral bodies. The neurological symptoms of the patient were attributed to this specific pathology due to the complete agreement between the location of the cyst and the nervous rule area of the compressed thoracic vertebrae. Despite our strongly suggestions for surgery the patient denied any treatment. Conclusion In controversy with the common faith that the spine plays the role of the natural barrier to the further expansion of cystic lesions, our case clearly indicates that, exceptionally, mediastinal cysts may cause severe vertebral complications. Therefore, early excision should be considered especially in young patients or where close follow up is uncertain.

  14. A probabilistic algorithm for interactive huge genome comparison. (United States)

    Courtois, P R; Moncany, M L


    We designed a new probabilistic algorithm, named PAGEC (probabilistic algorithm for genome comparison), which allowed a highly interactive study of long genomic strings. The comparison between two nucleic acid sequences is based on the creation of multiple index tables, which drastically reduces processing time for huge genomes, e.g. 13 min for a 4 Mb/4 Mb comparison. PAGEC lowered the need for memory when compared with other types of algorithm and took into account the low resolution of the final representation (paper or computer screen). Considering that standard printers permit a 300 d.p.i. resolution, the loss of computed information due to the probabilistic conception of the algorithm was not usually noticeable in the present study, mainly due to increased genomic sizes. Refinement was possible through an interactive zooming system, which enabled the visualization of the lexical base sequences of a considered part of both of the studied genomes. Biological examples of computation based on yeast and animal nucleic acid sequences presented in this paper reveal the flexibility of the PAGEC program, which is a valuable tool for genetic studies as it offers a solution to an important problem that will become even more important as time passes.

  15. Slip Development and Instability on a Heterogeneously Loaded Fault with Power-Law Slip-Weakening (United States)

    Rice, J. R.; Uenishi, K.


    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] ( 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

  16. Nonlinear dynamical triggering of slow slip

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Paul A [Los Alamos National Laboratory; Knuth, Matthew W [WISCONSIN; Kaproth, Bryan M [PENN STATE; Carpenter, Brett [PENN STATE; Guyer, Robert A [Los Alamos National Laboratory; Le Bas, Pierre - Yves [Los Alamos National Laboratory; Daub, Eric G [Los Alamos National Laboratory; Marone, Chris [PENN STATE


    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

  17. GPS dynamic cycle slip detection and correction with baseline constraint

    Institute of Scientific and Technical Information of China (English)

    Liu Zhenkun; Huang Ahunji


    When the cycle slips take place in the attitude determination of a moving platform, the precision of the attitude will be impaired badly. A method of cycle slip detection and correction is proposed, which is suitable to the dynamic measurement using GPS carrier phase: the cycle slips detection is first achieved by triple difference observables, then the cycle slips correction is performed with baseline length constraint. The simulation results show that the proposed method is effective to the dynamic cycle slips problem.

  18. MRI Verification of a Case of Huge Infantile Rhabdomyoma (United States)

    Ramadani, Naser; Kreshnike, Kreshnike Dedushi; Muçaj, Sefedin; Kabashi, Serbeze; Hoxhaj, Astrit; Jerliu, Naim; Bejiçi, Ramush


    Introduction: Cardiac rhabdomyoma is type of benign myocardial tumor that is the most common fetal cardiac tumor. Cardiac rhabdomyomas are usually detected before birth or during the first year of life. They account for over 60% of all primary cardiac tumors. Case report: A 6 month old child with coughing and obstruction in breathing, was hospitalized in the Pediatric Clinic in UCCK, Pristine. The difficulty of breathing was heard and the pathological noise of the heart was noticed from the pediatrician. In the echo of the heart at the posterior and apico-lateral part of the left ventricle a tumoral mass was presented with the dimensions of 56 × 54 mm that forwarded the contractions of the left ventricle, the mass involved also the left ventricle wall and was not vascularized. The right ventricle was deformed and with the shifting of the SIV on the right the contractility was preserved. Aorta, the left arch and AP were normal with laminar circulation. The pericard was presented free. Radiography of thoracic organs was made; it resulted on cardiomegaly and significant bronchovascular drawing. It was completed with an MRI and it resulted on: Cardiomegaly due to large tumoral mass lesion (60×34 mm) involving lateral wall of left ventricle. It was isointense to the muscle on T1W images, markedly hyperintense on T2W images. There were a few septa or bant like hypointensities within lesion. On postcontrast study it showed avid enhancement. The left ventricle volume was decreased. Mild pericardial effusion was also noted. Surgical intervention was performed and it resulted on the histopathological aspect as a huge infantile rhadbomyoma. Conclusion: In most cases no treatment is required and these lesions regress spontaneously. Patients with left ventricular outflow tract obstruction or refractory arrhythmias respond well to surgical excision. Rhabdomyomas are frequently diagnosed by means of fetal echocardiography during the prenatal period. PMID:27147810

  19. Single-Path Sigma from a Huge Dataset in Taiwan (United States)

    Sung, Chih-Hsuan; Lee, Chyi-Tyi


    Ground-motion variability, which was used in the probabilistic seismic hazard analysis (PSHA) in computing annual exceedence probability, is composed of random variability (aleatory uncertainty) and model uncertainty (epistemic uncertainty). Finding random variability of ground motions has become an important issue in PSHA, and only the random variability can be used in deriving the annual exceedence probability of ground-motion. Epistemic uncertainty will be put in the logic tree to estimate the total uncertainty of ground-motion. In the present study, we used about 18,859 records from 158 shallow earthquakes (Mw > 3.0, focal depth ≤ 35 km, each station has at least 20 records) form the Taiwan Strong-Motion Instrumentation Program (TSMIP) network to analyse the random variability of ground-motion. First, a new ground-motion attenuation model was established by using this huge data set. Second, the residuals from the median attenuation were analysed by direct observation on inter-event variability and site-specific variability. Finally, the single-path variability was found by a moving-window method on either single-earthquake residuals or single-station residuals. A variogram method was also used to find minimum variability for intra-event residuals and inter-event residuals, respectively. Results reveal that 90% of the single-path sigma σSP are ranging from 0.219 to 0.254 (ln unit) and are 58% to 64% smaller than the total sigma (σT =0.601). The single-site sigma (σSS) are also 39%-43% smaller. If we use only random variability (single-path sigma) in PSHA, then the resultant hazard level would be 28% and 25% lower than the traditional one (using total sigma) in 475-year and in 2475-year return period, respectively, in Taipei.

  20. Progressive slip after removal of screw fixation in slipped capital femoral epiphysis: two case reports

    Directory of Open Access Journals (Sweden)

    Engelsma Yde


    Full Text Available Abstract Introduction In slipped capital femoral epiphysis the femoral neck displaces relative to the head due to weakening of the epiphysis. Early recognition and adequate surgical fixation is essential for a good functional outcome. The fixation should be secured until the closure of the epiphysis to prevent further slippage. A slipped capital femoral epiphysis should not be confused with a femoral neck fracture. Case presentation Case 1 concerns a 15-year-old boy with an adequate initial screw fixation of his slipped capital femoral epiphysis. Unfortunately, it was thought that the epiphysis had healed and the screw was removed after 11 weeks. This caused new instability with a progressive slip of the femoral epiphysis and subsequently re-fixation and a subtrochanteric correction osteotomy was obligatory. Case 2 concerns a 13-year-old girl with persistent hip pain after screw fixation for slipped capital femoral epiphysis. The screw was removed as lysis was seen around the screw on the hip X-ray. This operation created a new unstable situation and the slip progressed resulting in poor hip function. A correction osteotomy with re-screw fixation was performed with a good functional result. Conclusion A slipped epiphysis of the hip is not considered ‘healed’ after a few months. Given the risk of progression of the slip the fixation material cannot be removed before closure of the growth plate.

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

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


    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.

  2. Slip in viscous contact-line movement (United States)

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


    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

  3. Gait abnormalities following slipped capital femoral epiphysis. (United States)

    Song, Kit M; Halliday, Suzanne; Reilly, Chris; Keezel, William


    The authors evaluated 30 subjects with treated unilateral slipped capital femoral epiphysis and a range of severity from mild to severe to characterize gait and strength abnormalities using instrumented three-dimensional gait analysis and isokinetic muscle testing. For slip angles less than 30 degrees, kinematic, kinetic, and strength variables were not significantly different from age- and weight-matched controls. For moderate to severe slips, as slip angle increased, passive hip flexion, hip abduction, and internal rotation in the flexed and extended positions decreased significantly. Persistent pelvic obliquity, medial lateral trunk sway, and trunk obliquity in stance increased, as did extension, adduction, and external rotation during gait. Gait velocity and step length decreased with increased amount of time spent in double limb stance. Hip abductor moment, hip extension moment, knee flexion moment, and ankle dorsiflexion moment were all decreased on the involved side. Hip and knee strength also decreased with increasing slip severity. All of these changes were present on the affected and to a lesser degree the unaffected side. Body center of mass translation or pelvic obliquity in mid-stance greater than one standard deviation above normal correlated well with the impression of compensated or uncompensated Trendelenburg gait.

  4. [An experimental study on freudian slips]. (United States)

    Köhler, Thomas; Simon, Patrick


    We attempted to replicate findings of a frequently cited study by Motley. This author had used a tachistoskope to present his participants pairs of words which had a meaning after exchanging the initial letters of each word ("spoonerisms"). In accordance with the psychoanalytic theory of Freudian slips, Motley was able to show that under the impression of a sexually stimulating situation more sexual words were read; under the threat of electric shock spoonerisms appeared more often in words with reference to electricity. In our study we tried to induce spoonerisms by presentation of short written texts of erotic, aggressive and neutral content. It could be shown that after reading the erotic and the aggressive text, slips were produced more often than following the text of neutral content. In addition, significantly more slips of erotic kind occurred after reading the erotic text, whereas more aggressive slips were observed immediately after lecture of the text with aggressive content. We were therefore able to replicate Motley's findings and thus also corroborated assumptions made by Freud on the origin of slips of the tongue.

  5. Slip patterns and preferred dislocation boundary planes

    DEFF Research Database (Denmark)

    Winther, G.


    The planes of deformation induced extended planar dislocation boundaries are analysed in two different co-ordinate systems, namely the macroscopic system defined by the deformation axes and the crystallographic system given by the crystallographic lattice. The analysis covers single and polycryst......The planes of deformation induced extended planar dislocation boundaries are analysed in two different co-ordinate systems, namely the macroscopic system defined by the deformation axes and the crystallographic system given by the crystallographic lattice. The analysis covers single...... and polycrystals of fcc metals in three deformation modes (rolling, tension and torsion). In the macroscopic system, boundaries lie close to the macroscopically most stressed planes. In the crystallographic system, the boundary plane depends on the grain/crystal orientation. The boundary planes in both co......-ordinate systems are rationalised based on the slip. The more the slip is concentrated on a slip plane, the closer the boundaries lie to this. The macroscopic preference arises from the macroscopic directionality of the slip. The established relations are applied to (a) prediction of boundary planes from slip...

  6. Constraining the roughness degree of slip heterogeneity

    KAUST Repository

    Causse, Mathieu


    This article investigates different approaches for assessing the degree of roughness of the slip distribution of future earthquakes. First, we analyze a database of slip images extracted from a suite of 152 finite-source rupture models from 80 events (Mw = 4.1–8.9). This results in an empirical model defining the distribution of the slip spectrum corner wave numbers (kc) as a function of moment magnitude. To reduce the “epistemic” uncertainty, we select a single slip model per event and screen out poorly resolved models. The number of remaining models (30) is thus rather small. In addition, the robustness of the empirical model rests on a reliable estimation of kc by kinematic inversion methods. We address this issue by performing tests on synthetic data with a frequency domain inversion method. These tests reveal that due to smoothing constraints used to stabilize the inversion process, kc tends to be underestimated. We then develop an alternative approach: (1) we establish a proportionality relationship between kc and the peak ground acceleration (PGA), using a k−2 kinematic source model, and (2) we analyze the PGA distribution, which is believed to be better constrained than slip images. These two methods reveal that kc follows a lognormal distribution, with similar standard deviations for both methods.

  7. Breddin's Graph For Fault and Slip Data (United States)

    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.

  8. Quantifying slip balance in the earthquake cycle: Coseismic slip model constrained by interseismic coupling

    KAUST Repository

    Wang, Lifeng


    The long-term slip on faults has to follow, on average, the plate motion, while slip deficit is accumulated over shorter time scales (e.g., between the large earthquakes). Accumulated slip deficits eventually have to be released by earthquakes and aseismic processes. In this study, we propose a new inversion approach for coseismic slip, taking interseismic slip deficit as prior information. We assume a linear correlation between coseismic slip and interseismic slip deficit, and invert for the coefficients that link the coseismic displacements to the required strain accumulation time and seismic release level of the earthquake. We apply our approach to the 2011 M9 Tohoku-Oki earthquake and the 2004 M6 Parkfield earthquake. Under the assumption that the largest slip almost fully releases the local strain (as indicated by borehole measurements, Lin et al., 2013), our results suggest that the strain accumulated along the Tohoku-Oki earthquake segment has been almost fully released during the 2011 M9 rupture. The remaining slip deficit can be attributed to the postseismic processes. Similar conclusions can be drawn for the 2004 M6 Parkfield earthquake. We also estimate the required time of strain accumulation for the 2004 M6 Parkfield earthquake to be ~25 years (confidence interval of [17, 43] years), consistent with the observed average recurrence time of ~22 years for M6 earthquakes in Parkfield. For the Tohoku-Oki earthquake, we estimate the recurrence time of~500-700 years. This new inversion approach for evaluating slip balance can be generally applied to any earthquake for which dense geodetic measurements are available.

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

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


    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

  10. Pulmonary hypertension with a huge thrombosis in main stem of pulmonary artery

    Institute of Scientific and Technical Information of China (English)

    杨萍; 曾红; 孟繁波; 赵林阳


    @@A huge thrombosis in the main stem of the pulmonary artery (PA) with pulmonary hypertension has rarely been reported. We present two cases diagnosed and treated in our hospital. One suffered from polyarteritis with a huge thrombus in PA revealed at autopsy. The second case had congenital heart disease of the patent artery duct; and the huge thrombus was found on echocardiogram and extirpated in surgery.

  11. Huge ascending aortic aneurysm with an intraluminal thrombus in an embolic event-free patient. (United States)

    Parato, Vito Maurizio; Prifti, Edvin; Pezzuoli, Franco; Labanti, Benedetto; Baboci, Arben


    We present a case of an 87-year-old male patient with a huge ascending aortic aneurysm, filled by a huge thrombus most probably due to previous dissection. This finding was detected by two-dimensional transthoracic echocardiography and contrast-enhanced computed tomography (CT) angiography scan. The patient refused surgical treatment and was medically treated. Despite the huge and mobile intraluminal thrombus, the patient remained embolic event-free up to 6 years later, and this makes the case unique.

  12. Quake clamps down on slow slip (United States)

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


    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.

  13. Vaporization of fault water during seismic slip (United States)

    Chen, Jianye; Niemeijer, André R.; Fokker, Peter A.


    Laboratory and numerical studies, as well as field observations, indicate that phase transitions of pore water might be an important process in large earthquakes. We present a model of the thermo-hydro-chemo-mechanical processes, including a two-phase mixture model to incorporate the phase transitions of pore water, occurring during fast slip (i.e., a natural earthquake) in order to investigate the effects of vaporization on the coseismic slip. Using parameters from typical natural faults, our modeling shows that vaporization can indeed occur at the shallow depths of an earthquake, irrespective of the wide variability of the parameters involved (sliding velocity, friction coefficient, gouge permeability and porosity, and shear-induced dilatancy). Due to the fast kinetics, water vaporization can cause a rapid slip weakening even when the hydrological conditions of the fault zone are not favorable for thermal pressurization, e.g., when permeability is high. At the same time, the latent heat associated with the phase transition causes the temperature rise in the slip zone to be buffered. Our parametric analyses reveal that the amount of frictional work is the principal factor controlling the onset and activity of vaporization and that it can easily be achieved in earthquakes. Our study shows that coseismic pore fluid vaporization might have played important roles at shallow depths of large earthquakes by enhancing slip weakening and buffering the temperature rise. The combined effects may provide an alternative explanation for the fact that low-temperature anomalies were measured in the slip zones at shallow depths of large earthquakes.

  14. Efficacy of hepatic resection for huge (≥ 10 cm) hepatocellular carcinoma: good prognosis associated with the uninodular subtype. (United States)

    Zhu, Shao-Liang; Chen, Jie; Li, Hang; Li, Le-Qun; Zhong, Jian-Hong


    The value of hepatic resection (HR) for huge hepatocellular carcinomas (HCC) (≥ 10 cm in diameter) remains controversial. The aim of this study is to evaluate the efficacy of hepatic resection (HR) for patients with huge HCC. A total of 739 patients with huge HCC (≥ 10 cm in diameter) (huge HCC group, n = 244) or small HCC (huge HCC were identified based on Cox regression analyses. The hospital mortality of these two groups were similar (P = 0.252). The 5-year OS of huge HCC group and small HCC group were 30.3% and 51.9%, respectively (P huge HCC had a significant higher 5-year OS (50.6%) than mutinodular huge HCC (26.9%) (P = 0.016). Multivariate analysis revealed that uninodular huge HCC and absence of PVTT independently predicted better OS for huge HCC patients. HR is a safe and effective approach for the treatment of huge HCC, especially for the uninodular subtype.

  15. Momentum compaction and phase slip factor

    Energy Technology Data Exchange (ETDEWEB)

    Ng, K.Y.; /Fermilab


    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.

  16. Slipping magnetic reconnection in coronal loops. (United States)

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


    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.

  17. Fault zone roughness controls slip stability (United States)

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


    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 (Sqstress 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 (Sqstress (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 nature of frictional contact. Significantly we suggest that bare fault surfaces may require a different stability criterion (based on

  18. Numerical Analysis of the Slip Velocity and Temperature-Jump in Microchannel Using Langmuir Slip Boundary Condition

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Woo; Kim, Hyun Goo; Lee, Do Hyung [Hanyang University, Seoul (Korea, Republic of)


    The slip velocity and the temperature jumps for low-speed flow in microchannels are investigated using Langmuir slip boundary condition. This slip boundary condition is suggested to simulate micro flow. The current study analyzes Langmuir slip boundary condition theoretically and it analyzed numerically micro-Couette flow, micro-Poiseuille flow and grooved microchannel flow. First, to prove validity for Langmuir slip condition, an analytical solution for micro-Couette flow is derived from Navier-Stokes equations with Langmuir slip conditions and is compared with DSMC and an analytical solution with Maxwell slip boundary condition. Second, the numerical analysis is performed for micro-Poiseuille flow and grooved microchannel flow. The slip velocity and temperature distribution are compared with results of DSMC or Maxwell slip condition and those are shown in good agreement.

  19. Imbricated slip rate processes during slow slip transients imaged by low-frequency earthquakes (United States)

    Lengliné, O.; Frank, W. B.; Marsan, D.; Ampuero, J.-P.


    Low Frequency Earthquakes (LFEs) often occur in conjunction with transient strain episodes, or Slow Slip Events (SSEs), in subduction zones. Their focal mechanism and location consistent with shear failure on the plate interface argue for a model where LFEs are discrete dynamic ruptures in an otherwise slowly slipping interface. SSEs are mostly observed by surface geodetic instruments with limited resolution and it is likely that only the largest ones are detected. The time synchronization of LFEs and SSEs suggests that we could use the recorded LFEs to constrain the evolution of SSEs, and notably of the geodetically-undetected small ones. However, inferring slow slip rate from the temporal evolution of LFE activity is complicated by the strong temporal clustering of LFEs. Here we apply dedicated statistical tools to retrieve the temporal evolution of SSE slip rates from the time history of LFE occurrences in two subduction zones, Mexico and Cascadia, and in the deep portion of the San Andreas fault at Parkfield. We find temporal characteristics of LFEs that are similar across these three different regions. The longer term episodic slip transients present in these datasets show a slip rate decay with time after the passage of the SSE front possibly as t - 1 / 4. They are composed of multiple short term transients with steeper slip rate decay as t-α with α between 1.4 and 2. We also find that the maximum slip rate of SSEs has a continuous distribution. Our results indicate that creeping faults host intermittent deformation at various scales resulting from the imbricated occurrence of numerous slow slip events of various amplitudes.

  20. Efficient visualization of unsteady and huge scalar and vector fields (United States)

    Vetter, Michael; Olbrich, Stephan


    The simulation of climate data tends to produce very large data sets, which hardly can be processed in classical post-processing visualization applications. Within the most traditional post-processing scenarios the visualization pipeline consisting of the processes data generation, visualization mapping and rendering is distributed into two parts over the network or separated via file transfer: the data generation on a supercomputer on the one hand and the other tasks on a special visualization system on the other hand. That way either temporary data sets with huge volume have to be transferred over the network, which leads to bandwidth bottlenecks and volume limitations. As an alternative all simulation and visualization processes are integrated in a monolithic application, where just 2D pixel data is stored, which reduces the user's possibilities for 3D interaction with visualization to frame skipping. Within the Climate Visualization Lab - as part of the Cluster of Excellence "Integrated Climate System Analysis and Prediction" (CliSAP at the University of Hamburg, in cooperation with the German Climate Computing Center (DKRZ) - we plan to integrate a different approach, which has been proven to be successful in former meteorology applications, e.g. PALM (Parallel Large Eddy Simulation Model). Our software framework DSVR is based on the separation of the process chain between the mapping and the rendering processes. We have developed a parallelized visualization library based on MPI and evaluated on various supercomputers. DSVR can be used to integrate the visualization into a parallel simulation model to support in-situ processing, resulting in a sequence of time-based geometric 3D objects which can be interactively rendered in a separate 3D viewer application. To meet the actual requirements (a) to visualize existing data sets, (b) to support more than rectilinear grids, and (c) to integrate in-situ processing in the ICON model, all based on our DSVR framework

  1. The Distribution of Fault Slip Rates and Oblique Slip Patterns in the Greater Los Angeles, CA Region (United States)

    Harper, H.; Marshall, S. T.


    The Los Angeles basin is host to a complex network of active strike-slip, reverse, and oblique slip faults. Because of the large metropolitan region occupying the basin, even moderately large earthquakes (M6+) pose a significant natural hazard. Since geologic estimates have not fully characterized the distribution of active fault slip rates in the region, we use a mechanical model driven by geodetically-measured shortening rates to calculate the full three-dimensional fault slip rate distributions in the region. The modeled nonplanar fault geometries are relatively well-constrained, and use data from the SCEC community fault model. Area-weighted average fault slip rates predicted by the model match previously measured geologic slip rates in most cases; however, some geologic measurements were made in locations where the slip rate is non-characteristic of the fault (e.g. near a fault tip) and the geologic slip rate estimate disagrees with the model-predicted average slip rate. The largest discrepancy between the model predictions and geologic estimates occurs on the Sierra Madre fault, which has a model-predicted slip rate approximately 2 mm/yr greater than the geologic estimates. An advantage of the model is that it can predict the full three-dimensional mechanically compatible slip distribution along all modeled faults. The fault surface slip distribution maps show complex oblique slip patterns that arise due to the nonplanar geometries and mechanical interactions between intersecting and neighboring faults. For example, the Hollywood fault exhibits a net slip of 0.7 mm/yr at depth which increases to 1.6 mm/yr where it is intersected by the Santa Monica fault in the near-surface. Model results suggest that nearly all faults in the region have an oblique component of slip at depth, so slip rate estimates of only dip or strike-slip may underestimate the total net slip rates and seismic hazards in the region.

  2. Spatially uniform microflows induced by thermoviscous expansion along a traveling temperature wave: Analogies with electro-osmotic transport (United States)

    Pal, Debashis; Chakraborty, Suman


    We discover that thermoviscous expansion along a traveling wave in a microfluidic channel may be capable of generating a spatially uniform flow profile in a time-averaged sense. We further delineate that the resultant complex flow characteristics, realized by virtue of an intricate interplay between thermal compression-expansion waves and temperature-dependent viscosity variations and controlled by an external heating, may be remarkably characterized by a unique thermal penetration depth scale (analogous to Debye length in electro-osmosis) and a velocity scale (analogous to the Helmholtz Smulochowski velocity in electro-osmosis) that in turn depends on the considerations of “thin” and “thick” microchannel limits, as dictated by the thermal penetration depth as compared to the lateral extent of the microfluidic channel. We show that, when the thermal penetration depth is small as compared to the channel height, a uniform velocity profile is generated in the channel in a time-averaged sense. The velocity scale characterizing this uniform flow may be represented by a function of the thermal diffusivity, volumetric expansion coefficient and thermal viscosity coefficient of the fluid, characteristic amplitude and speed of the thermal wave, as well as the channel height. Results from the present study are expected to provide valuable insights towards arresting hydrodynamic dispersion in microchannels by nonelectrochemical means, following a pH-independent route.

  3. Dynamical trapping of colloids at the stagnation points of electro-osmotic vortices of the second kind (United States)

    Green, Yoav; Yossifon, Gilad


    By applying a stepwise overlimiting voltage to a nanoslot system in equilibrium, it is possible to follow the time evolution of the electroconvective instability vortex array via the depletion dynamics or, alternatively, by following dielectrophoretically trapped particles at the stagnation points of each of the hydrodynamic vortex pairs. Particles are advected to the stagnation point by the hydrodynamics, where they are trapped by a short-range dielectrophoretic force. It is experimentally confirmed that the wavelength selection process occurs at the diffusive time scale and that the wavelength selection mechanism, started by the Rubinstein and Zaltzman electroconvective instability is eventually determined by the system lateral geometry and dictated by Dukhin's electro-osmosis of the second kind. The steady-state case was numerically studied by solving the fully coupled electroconvective problem, confirming that the vortex stagnation point is indeed of a converging type. The particle's planar (two-dimensional) equations of motion are solved after adding a dielectrophoretic force that accounts for quasi-three-dimensional effects. It is shown that this force can account for trapping at the nanoslot interface.

  4. Concentration Polarization and Nonequilibrium Electro-osmotic Instability at an Ion-Selective Surface Admitting Normal Flow (United States)

    Khair, Aditya


    We revisit and build upon on the prototypical problem of ion transport across a flat ideal ion-selective surface. Specifically, we examine the influence of imposed fluid flows on concentration polarization (CP) and electrokinetic instability at over-limiting currents. We consider an ion-selective surface, or membrane, that admits a uniform flow across itself. The membrane contacts an electrolyte, whose concentration is uniform in a well-mixed region at a prescribed distance from the membrane. A voltage across the system drives an ionic current, leading to CP in the ``unstirred layer'' between the membrane and well-mixed bulk. The CP reflects a balance between advection of ions with the ``normal flow'' and diffusion. A Peclet number, Pe, parameterizes their relative importance; note, Pe is signed, as the flow can be toward or away from the membrane. An asymptotic analysis for thin Debye layers reveals a nonlinear CP profile, in contrast to the familiar linear profile at Pe=0. Next, we consider over-limiting currents, wherein a non-equilibrium space-charge layer emerges near the membrane surface. Finally, we examine the instability of the quiescent concentration polarization due to second-kind electro-osmosis in the space-charge layer. A stability analysis shows that the imposed normal flow can enhance or retard the instability, depending on its direction.

  5. Demonstration of Electro-Osmotic Pulse Technology in Earth-Covered Magazines at Fort A.P. Hill, VA (United States)


    Fahrenheit (F-32)/1.8 degrees Celsius feet 0.3048 meters gallons (U.S. liquid) 3.785412 E-03 cubic meters inches 0.0254 meters mils 0.0254 millimeters...437 -315 -256 0.234 2. -480 -348 -310 0.211 5. -502 -413 -364 0.046 6. - 451 -382 -267 0.046 9. -452 -314 -285 0.186 10. -461 -342 -322 0.102 1

  6. Electro-Osmotic Pulse Technology: A Novel Solution to Severe Water Intrusion Problems in Earth Covered Magazines (United States)


    conditions. This is also shown in a potential-pH equilibrium diagram (Fig. 10) by Pourbaix (1966). O 2 + 2H2O + 4e- 4(OH-) 2H+ + 2e- H2 2H+ + 2e- H2...INside and OUTside the ground ring. Figure 11 is a plot of the steel potential over time using a Cu- CuSO4 half cell. Note that the potential...reaches a steady state condition of around +4.25 VCSE and never goes negative. To convert the Cu- CuSO4 (VCSE) potential measurements to VSCE

  7. Hydrodynamic slip length as a surface property (United States)

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


    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.

  8. Hydrodynamic slip length as a surface property. (United States)

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


    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.

  9. Self-consistent dynamics of wall slip

    NARCIS (Netherlands)

    Dubbeldam, J.L.A.; Molenaar, J.


    A simple molecular model is studied to explain wall slip in a polymer melt. We consider a tube model for tethered chains in which the most important relaxation mechanisms: convective constraint release and chain stretching (retraction), are incorporated. Furthermore, we take the interactions between

  10. Fibrous dysplasia of the rib presenting as a huge chest wall tumor: report of a case. (United States)

    Chang, B S; Lee, S C; Harn, H J


    Fibrous dysplasia of the rib is not uncommon, but is rarely demonstrated as a huge chest wall mass with severe clinical symptoms. A 59-year-old patient, presenting with a huge, rapidly expanding chest wall tumor compressing the lung, liver and heart accompanied by chest pain and dyspnea, is reported. The tumor was success-fully excised by local radical resection.

  11. Huge van Bordeeus : een ridder van Karel de Grote op avontuur in het Oosten

    NARCIS (Netherlands)

    Lens, Maria Johanna


    'Huge van Bordeeus' is de dissertatie van Maria Lens. Hierin doet zij verslag van haar onderzoek naar de Middelnederlandse overlevering van een Franse tekst, 'Huon de Bordeaux', over de ridder Huge van Bordeeus. Deze veertiende-eeuwse ridder, leenman van Karel de Grote, moet de baard en vier tanden

  12. Next generation GNSS single receiver cycle slip reliability

    NARCIS (Netherlands)

    Teunissen, P.J.G.; De Bakker, P.F.


    In this contribution we study the multi-frequency, carrier-phase slip detection capabilities of a single receiver. Our analysis is based on an analytical expression that we present for themulti-frequencyminimal detectable carrier phase cycle slip.

  13. Effects of mental fatigue on biomechanics of slips. (United States)

    Lew, Fui Ling; Qu, Xingda


    The objective of this study was to investigate the effects of mental fatigue on biomechanics of slips. A total of 44 healthy young participants were evenly categorised into two groups: no fatigue and mental fatigue. Mental fatigue was induced by performing an AX-continuous performance test. The participants in both groups were instructed to walk on a linear walkway, and slips were induced unexpectedly during walking. We found that mental fatigue has adverse effects in all the three phases of slips. In particular, it leads to increased likelihood of slip initiation, poorer slip detection and a more insufficient reactive recovery response to slips. Based on the findings from the present study, we can conclude that mental fatigue is a risk factor for slips and falls. In order to prevent slip-induced falls, interventions, such as providing frequent rest breaks, could be applied in the workplace to avoid prolonged exposures to cognitively demanding activities.

  14. Transarterial chemoembolization for huge hepatocellular carcinoma with diameter over ten centimeters: a large cohort study. (United States)

    Xue, Tongchun; Le, Fan; Chen, Rongxin; Xie, Xiaoying; Zhang, Lan; Ge, Ningling; Chen, Yi; Wang, Yanhong; Zhang, Boheng; Ye, Shenglong; Ren, Zhenggang


    Patients with huge hepatocellular carcinoma >10 cm in diameter represent a special subgroup for treatment. To date, there are few data and little consensus on treatment strategies for huge hepatocellular carcinoma. In this study, we summarized the effects and safety of transarterial chemoembolization for huge hepatocellular carcinoma. A retrospective study was performed based on a large cohort of patients (n = 511) with huge hepatocellular carcinoma who underwent serial transarterial chemoembolization between January 2008 to December 2011 and were followed up until March 2013. We found median survival time was 6.5 months. On multivariate analysis, Child-Pugh class (A versus B) (p huge hepatocellular carcinoma and is recommended as a component of combination therapy. In addition, patients with good liver function and low alpha-fetoprotein levels may acquire greater survival benefits from transarterial chemoembolization.

  15. Flexural-slip during visco-elastic buckle folding (United States)

    Damasceno, Davi R.; Eckert, Andreas; Liu, Xiaolong


    Flexural-slip is considered as an important mechanism during folding and a general conceptual and qualitative understanding has been provided by various field studies. However, quantitative evidence of the importance of the flexural-slip mechanism during fold evolution is sparse due to the lack of suitable strain markers. In this study, 2D finite element analysis is used to overcome these disadvantages and to simulate flexural-slip during visco-elastic buckle folding. Variations of single and multilayer layer fold configurations are investigated, showing that flexural-slip is most likely to occur in effective single layer buckle folds, where slip occurs between contacts of competent layers. Based on effective single layer buckle folds, the influence of the number of slip surfaces, the degree of mechanical coupling (based on the friction coefficient), and layer thickness, on the resulting slip distribution are investigated. The results are in agreement with the conceptual flexural-slip model and show that slip is initiated sequentially during the deformation history and is maximum along the central slip surface of the fold limb. The cumulative amount of slip increases as the number of slip surfaces is increased. For a lower degree of mechanical coupling increased slip results in different fold shapes, such as box folds, during buckling. In comparison with laboratory experiments, geometrical relationships and field observations, the numerical modeling results show similar slip magnitudes. It is concluded that flexural-slip should represent a significant contribution during buckle folding, affecting the resulting fold shape for increased amounts of slip.

  16. Characterization of slip lines in single edge notched tension specimens


    Van Gerven, Filip; De Waele, Wim; Belato Rosado, Diego; Hertelé, Stijn


    The application of slip line analysis in weld failure assessment has not gained much attention to date. The presented research aims to predict slip line patterns taking into account the complex heterogeneous structure of the weld. A preliminary study based on Single Edge Notched Tension (SENT) test results sampling pure base material, i.e. not containing any welds is conducted to assess the impact of side grooves on slip line behaviour and to validate slip line theory and finite element analy...

  17. Evidence for Truncated Exponential Probability Distribution of Earthquake Slip

    KAUST Repository

    Thingbaijam, Kiran K. S.


    Earthquake ruptures comprise spatially varying slip on the fault surface, where slip represents the displacement discontinuity between the two sides of the rupture plane. In this study, we analyze the probability distribution of coseismic slip, which provides important information to better understand earthquake source physics. Although the probability distribution of slip is crucial for generating realistic rupture scenarios for simulation-based seismic and tsunami-hazard analysis, the statistical properties of earthquake slip have received limited attention so far. Here, we use the online database of earthquake source models (SRCMOD) to show that the probability distribution of slip follows the truncated exponential law. This law agrees with rupture-specific physical constraints limiting the maximum possible slip on the fault, similar to physical constraints on maximum earthquake magnitudes.We show the parameters of the best-fitting truncated exponential distribution scale with average coseismic slip. This scaling property reflects the control of the underlying stress distribution and fault strength on the rupture dimensions, which determines the average slip. Thus, the scale-dependent behavior of slip heterogeneity is captured by the probability distribution of slip. We conclude that the truncated exponential law accurately quantifies coseismic slip distribution and therefore allows for more realistic modeling of rupture scenarios. © 2016, Seismological Society of America. All rights reserverd.

  18. Optimization of Partial Slip Surface at Lubricated-MEMS

    NARCIS (Netherlands)

    Tauviqirrahman, M.; Ismail, R.; Schipper, D.J.; Jamari, J.; Suprijanto, Dr.


    This work reports the hydrodynamic performance (load support, friction force, friction coefficient, and volume flow) generated by a partial slip surface at lubricated-MEMS. The partial slip surface is optimized so that a maximum hydrodynamic load support could be obtained. The partial slip is applie

  19. Petroleum System of the Sufyan Depression at the Eastern Margin of a Huge Strike-slip Fault Zone in Central Africa

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yamin; GU Qin


    The present paper mainly studies the petroleum system of the Sufyan Depression in the Muglad Basin of central Africa and analyzes its control of hydrocarbon accumulation. On the basis of comprehensive analysis of effective source rock, reservoir bed types and source-reservoir-seal assemblages, petroleum system theory has been used to classify the petroleum system of the Sufyan Depression. Vertically, the Sufyan Depression consists of two subsystems. One is an Abu Gabra subsystem as a serf generating, accumulating and sealing assemblage. The other subsystem is composed of an Abu Gabra source rock, Bentiu channel sandstone reservoir and Darfur group shale seal, which is a prolific assemblage in this area. Laterally, the Sufyan Depression is divided into eastern and western parts with separate hydrocarbon generation centers more than 10 000 m deep. The potential of the petroleum system is tremendous. Recently, there has been a great breakthrough in exploration. The Sufyan C-1 well drilled in the central structural belt obtained high-yielding oil flow exceeding 100 tons per day and controlled geologic reserves of tens of millions of tons. The total resource potential of the Sufyan Depression is considerable. The central structural belt is most favorable as an exploration and development prospect.

  20. Phase Slips in Oscillatory Hair Bundles (United States)

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


    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

  1. Surface slip during large Owens Valley earthquakes

    KAUST Repository

    Haddon, E. K.


    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 approximate to 1.0 to 6.0 m and average 3.31.1 m (2 sigma). Vertical offsets are predominantly east-down between approximate to 0.1 and 2.4 m, with a mean of 0.80.5 m. The average lateral-to-vertical ratio compiled at specific sites is approximate to 6:1. Summing displacements across subparallel, overlapping rupture traces implies a maximum of 7-11 m and net average of 4.41.5 m, corresponding to a geologic M-w approximate to 7.5 for the 1872 event. We attribute progressively higher-offset lateral COPD peaks at 7.12.0 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 approximate to 0.6 and 1.6 mm/yr (1 sigma) over the late Quaternary.

  2. On the mechanism of cross slip in Ni3Al (United States)

    Milligan, Walter W.; Antolovich, Stephen D.


    The mechanical properties of L1(2) intermetallic alloys have been previously described by models based on the assumption that cube cross slip is the rate-limiting step. In this study, it was demonstrated that the cube cross-slip event must be reversible under a change in loading direction. This observation allows the cross-slip models to remain consistent with cyclic deformation data. Additionally, this observation was used as a critical test of the available cross-slip models. It was demonstrated that the rate-limiting step cannot be a total cross-slip event, in which both a/2 110-line superpartial dislocations cross slip to the cube plane. Conversely, the limited cross-slip event proposed by Paidar et al. (1984), was demonstrated to be consistent with the reversibility constraint. This lends additional experimental support to this model.

  3. Behaviors of small heterogeneity controlled by surrounding aseismic slip (United States)

    Aochi, Hideo; Ide, Satoshi


    Numerical simulations of slow slip events on a fault interface characterized by multi-scale heterogeneity (fractal patch model; Ide and Aochi, JGR, 2005; Ide, Proc. Jpn Acad. Ser. B, 2014) are carried out, supposing that characteristic distance in the slip-dependent frictional law is scale-dependent. We also consider slip-dependent stress accumulation on patches prior to the weakening process. Slip on small patches is enhanced significantly when background is releasing stress in the case of two patches model. Slip behaviors becomes complex when fractal patch model is considered. It is then difficult to detect the accentuation of slips on small patches. On the other hand, they are quiet (detectable statistically) when background slip is characterized by strengthening process.

  4. Effective slip for flow in a rotating channel bounded by stick-slip walls (United States)

    Ng, Chiu-On


    This paper aims to look into how system rotation may modify the role played by boundary slip in controlling flow through a rotating channel bounded by stick-slip walls. A semianalytical model is developed for pressure-driven flow in a slit channel that rotates about an axis perpendicular to its walls, which are superhydrophobic surfaces patterned with periodic alternating no-shear and no-slip stripes. The cases where the flow is driven by a pressure gradient parallel or normal to the stripes are considered. The effects of the no-shear area fraction on the velocities and effective slip lengths for the primary and secondary flows are investigated as functions of the rotation rate and the channel height. It is mathematically proved that the secondary flow rate is exactly the same in the two cases, irrespective of whether the primary flow is parallel or normal to the wall stripes. For any rotation speed, there is an optimal value of the no-shear area fraction at which the primary flow rate is maximum. This is a consequence of two competing effects: the no-shear part of the wall may serve to reduce the wall resistance, thereby enhancing the flow especially at low rotation, but it also weakens the formation of the near-wall Ekman layer, which is responsible for pumping the flow especially at high rotation. Wall slip in a rotating environment is to affect flow in the Ekman layer, but not flow in the geostrophic core.

  5. Suppression of strike-slip fault systems (United States)

    Curren, I. S.


    In orogens elongated parallel to a great circle about the Euler pole for the two bounding plates, theory requires simple-shear deformation in the form of distributed deformation or velocity discontinuities across strike-slip faults. This type of deformation, however, does not develop at all plate boundaries requiring toroidal motion. Using the global plate boundary model, PB2002 [Bird, 2003], as the basis for identifying areas where expected simple-shear deformation is absent or underdeveloped, it was also possible to identify two potential causes for this behavior: (1) the presence of extensive fracturing at right angles to the shear plane and (2) regional cover of flood basalts or andesites with columnar joints. To test this hypothesis, a new plane-stress finite-strain model was developed to study the effects of such pre-existing structures on the development of simple shear in a clay cake. A homogenous kaolinite-water mixture was poured into a deforming parallelogram box and partially dried to allow for brittle and plastic deformation at and below the surface of the clay, respectively. This was floated on a dense fluid foundation, effectively removing basal friction, and driven by a motor in a sinistral direction from the sides of the box. Control experiments produced classic Riedel model fault assemblages and discrete, through-going primary deformation zones (PDZs); experiments with pre-existing structures developed the same, though subdued and distributed, fault assemblages but did not develop through-going PDZs. Although formation of strike-slip faults was underdeveloped at the surface in clay with pre-existing structures, offset within the clay cake (measured, with respect to a fixed point, by markers on the clay surface) as a fraction of total offset of the box was consistently larger than that of the control experiments. This suggests that while the extent of surface faulting was lessened in clay with pre-existing structures, slip was still occurring at

  6. Huge hepatocellular carcinoma with multiple intrahepatic metastases: An aggressive multimodal treatment

    Directory of Open Access Journals (Sweden)

    Satoshi Yasuda


    Conclusion: Multimodal treatment involving hepatectomy and TACE might be a good treatment strategy for patients with huge HCC with multiple intrahepatic metastases if the tumors are localized in the liver without distant or peritoneal metastasis.

  7. A huge ovarian mucinous cystadenoma causing virilization, preterm labor, and persistent supine hypotensive syndrome during pregnancy. (United States)

    Kucur, Suna Kabil; Acar, Canan; Temizkan, Osman; Ozagari, Aysim; Gozukara, Ilay; Akyol, Atif


    Mucinous cystadenoma (MC) of the ovary is an unilateral, multilocular cystic benign epithelial tumor. Supposed to be hormone responsive, MC reaches huge sizes during pregnancy. Aortocaval compression is common during pregnancy, especially when the pregnant woman is in the supine position. However, the compression recovers with a change in position. The authors report the first case of a huge mucinous cystadenoma of the ovary complicating pregnancy and causing virilization, premature labor, and persistent supine hypotensive syndrome.

  8. Robot-assisted laparoscopic resection of a huge pelvic tumor: A case report. (United States)

    Jia, Zhuomin; Lyu, Xiangjun; Xu, Yong; Leonardi, Rosario; Zhang, Xu


    The traditional open surgery, for the treatment of huge tumor in the narrow space of pelvic cavity and in close proximity to pelvic organs and neurovascular structures, is very difficult and challenging. We report a case of huge neurilemmoma operated using the robot-assisted laparoscopy. We used interventional pre-operation embolization to control blood supply of tumor because MRI showed the tumor had a sufficient blood supply.

  9. The HUGE formula (hematocrit, urea and gender): association with cardiovascular risk. (United States)

    Robles, N R; Felix, F J; Fernandez-Berges, D; Perez-Castán, J; Zaro, M J; Lozano, L; Alvarez-Palacios, P; Garcia-Trigo, A; Tejero, V; Morcillo, Y; Hidalgo, A B


    To evaluate the relationship between chronic renal failure (CFR) defined through HUGE (hematocrit, urea and gender) formula score and the patient's cardiovascular risk measured through cardiovascular disease antecedents such as ischemic cardiopathy, cerebrovascular disease and peripheral arterial disease. The sample consisted of 2,831 subjects. Mean age was 51.2±14.7 years and 53.5% were female. Serum creatinine, urea, hematocrit and 24h proteinuria were analyzed. HUGE score was calculated from gender, urea and hematocrit. GFR was estimated from uncalibrated serum creatinine using the abbreviated Modification of Diet in Renal Disease equation (MDRD-4). UAE was measured in first morning urine sample. Using HUGE formula 2.2% (n = 61) of subjects had CRF. Of them, 12 (19.7%) had cardiovascular disease history. Among patients without CRF (n = 2770), 194 subjects had history of previous cardiovascular diseases (0.07%; p HUGE definition of CRF was 3.25 (p = 0.001, Mantel-Haenszel test). CFR was associated to higher pulse pressure (PP) and increased urinary albumin excretion. A significant cardiovascular risk was associated to the diagnosis of CRF through HUGE formula. This relation was closer than the obtained using MDRD estimated GFR in spite of a bigger sample. HUGE formula seems to be a useful tool for diagnosing CRF and evaluate the cardiovascular risk of these patients.

  10. Fault Scaling Relationships Depend on the Average Geological Slip Rate (United States)

    Anderson, J. G.; Biasi, G. P.; Wesnousky, S. G.


    This study addresses whether knowing the geological slip rates on a fault in addition to the rupture length improves estimates of magnitude (Mw) of continental earthquakes that rupture the surface, based on a database of 80 events that includes 57 strike-slip, 12 reverse, and 11 normal faulting events. Three functional forms are tested to relate rupture length L to magnitude Mw: linear, bilinear, and a shape with constant static stress drop. The slip rate dependence is tested as a perturbation to the estimates of magnitude from rupture length. When the data are subdivided by fault mechanism, magnitude predictions from rupture length are improved for strike-slip faults when slip rate is included, but not for reverse or normal faults. This conclusion is robust, independent of the functional form used to relate L to Mw. Our preferred model is the constant stress drop model, because teleseismic observations of earthquakes favor that result. Because a dependence on slip rate is only significant for strike-slip events, a combined relationship for all rupture mechanisms is not appropriate. The observed effect of slip rate for strike-slip faults implies that the static stress drop, on average, tends to decrease as the fault slip rate increases.

  11. Progressive slippage after pinning for slipped capital femoral epiphysis. (United States)

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


    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.

  12. Coseismic slip distribution of the 1923 Kanto earthquake, Japan (United States)

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


    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.

  13. Complicated Recurrence of Slip Events on a Uniform Circular Asperity (United States)

    Kato, N.


    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

  14. DEM simulation of growth normal fault slip (United States)

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


    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

  15. Boundary Slip and Surface Interaction: A Lattice Boltzmann Simulation

    Institute of Scientific and Technical Information of China (English)

    CHEN Yan-Yan; YI Hou-Hui; LI Hua-Bing


    The factors affecting slip length in Couette geometry flows are analysed by means of a two-phase mesoscopic lattice Boltzmann model including non-ideal fluid-fluid and fluid-wall interactions.The main factors influencing the boundary slip are the strength of interactions between fluid-fluid and fluid-wall particles.Other factors,such as fluid viscosity,bulk pressure may also change the slip length.We find that boundary slip only occurs under a certain density(bulk pressure).If the density is large enough,the slip length will tend to zero.In our simulations,a low density layer near the wall does not need to be postulated a priori but emerges naturally from the underlying non-ideal mesoscopic dynamics.It is the low density layer that induces the boundary slip.The results may be helpful to understand recent experimental observations on the slippage of micro flows.

  16. Closed central slip injuries--a missed diagnosis?

    LENUS (Irish Health Repository)

    Nugent, N


    The extensor apparatus of the finger is a complex structure and injury can lead to significant digital dysfunction. Closed central slip injuries may be missed or diagnosis delayed because of lack of an open wound and often no radiographic abnormality, and can result in boutonniere deformities if untreated. This study aimed to quantify the number of patients attending with closed central slip injuries and to ascertain if the initial diagnosis was correct. The number of patients presenting to us over a 6 month period was recorded. The original diagnosis, time to diagnosis of central slip injury and the presence\\/absence of a boutonniere deformity were recorded. Ten patients were included in the study. Seven (70%) injuries were due to sport. Eight (80%) had a delayed diagnosis of central slip injury. Six (60%) had previously presented to general practitioners or emergency departments. Seven (70%) had boutonniere deformities. Closed central slip injuries can be missed. Simple clinical tests can diagnose central slip disruption.

  17. Prediction of fluid velocity slip at solid surfaces

    DEFF Research Database (Denmark)

    Hansen, Jesper Schmidt; Todd, Billy; Daivis, Peter


    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......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...

  18. Inverting measurements of surface slip on the Superstition Hills fault (United States)

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


    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

  19. On Slip Transmission Criteria in Experiments and Crystal Plasticity Models

    CERN Document Server

    Bayerschen, E; Reddy, B D; Böhlke, T


    A comprehensive overview is given on the slip transmission criteria for grain boundaries in the experimental literature, with a focus on slip system and grain boundary orientation. The use of these geometric criteria in continuum crystal plasticity models is briefly discussed. Perspectives on additional experimentally motivated criteria used in computational simulations are given. The theoretical framework of Gurtin (2008, J. Mech. Phys. Solids 56, p. 640) is reviewed for the single slip case with the aim of showing explicitly the connections to the experimentally developed criteria for slip transmission that are not discussed in the work itself.

  20. Slip and flow of hard-sphere colloidal glasses. (United States)

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


    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. Stochastic Wheel-Slip Compensation Based Robot Localization and Mapping

    Directory of Open Access Journals (Sweden)



    Full Text Available Wheel slip compensation is vital for building accurate and reliable dead reckoning based robot localization and mapping algorithms. This investigation presents stochastic slip compensation scheme for robot localization and mapping. Main idea of the slip compensation technique is to use wheel-slip data obtained from experiments to model the variations in slip velocity as Gaussian distributions. This leads to a family of models that are switched depending on the input command. To obtain the wheel-slip measurements, experiments are conducted on a wheeled mobile robot and the measurements thus obtained are used to build the Gaussian models. Then the localization and mapping algorithm is tested on an experimental terrain and a new metric called the map spread factor is used to evaluate the ability of the slip compensation technique. Our results clearly indicate that the proposed methodology improves the accuracy by 72.55% for rotation and 66.67% for translation motion as against an uncompensated mapping system. The proposed compensation technique eliminates the need for extro receptive sensors for slip compensation, complex feature extraction and association algorithms. As a result, we obtain a simple slip compensation scheme for localization and mapping.

  2. Newtonian self-gravitating system in a relativistic huge void universe model (United States)

    Nishikawa, Ryusuke; Nakao, Ken-ichi; Yoo, Chul-Moon


    We consider a test of the Copernican Principle through observations of the large-scale structures, and for this purpose we study the self-gravitating system in a relativistic huge void universe model which does not invoke the Copernican Principle. If we focus on the the weakly self-gravitating and slowly evolving system whose spatial extent is much smaller than the scale of the cosmological horizon in the homogeneous and isotropic background universe model, the cosmological Newtonian approximation is available. Also in the huge void universe model, the same kind of approximation as the cosmological Newtonian approximation is available for the analysis of the perturbations contained in a region whose spatial size is much smaller than the scale of the huge void: the effects of the huge void are taken into account in a perturbative manner by using the Fermi-normal coordinates. By using this approximation, we derive the equations of motion for the weakly self-gravitating perturbations whose elements have relative velocities much smaller than the speed of light, and show the derived equations can be significantly different from those in the homogeneous and isotropic universe model, due to the anisotropic volume expansion in the huge void. We linearize the derived equations of motion and solve them. The solutions show that the behaviors of linear density perturbations are very different from those in the homogeneous and isotropic universe model.

  3. Fluid pressures at the shoe-floor-contaminant interface during slips: effects of tread and implications on slip severity. (United States)

    Beschorner, Kurt E; Albert, Devon L; Chambers, April J; Redfern, Mark S


    Previous research on slip and fall accidents has suggested that pressurized fluid between the shoe and floor is responsible for initiating slips yet this effect has not been verified experimentally. This study aimed to (1) measure hydrodynamic pressures during slipping for treaded and untreaded conditions; (2) determine the effects of fluid pressure on slip severity; and (3) quantify how fluid pressures vary with instantaneous resultant slipping speed, position on the shoe surface, and throughout the progression of the slip. Eighteen subjects walked on known dry and unexpected slippery floors, while wearing treaded and untreaded shoes. Fluid pressure sensors, embedded in the floor, recorded hydrodynamic pressures during slipping. The maximum fluid pressures (mean+/-standard deviation) were significantly higher for the untreaded conditions (124+/-75 kPa) than the treaded conditions (1.1+/-0.29 kPa). Maximum fluid pressures were positively correlated with peak slipping speed (r=0.87), suggesting that higher fluid pressures, which are associated with untreaded conditions, resulted in more severe slips. Instantaneous resultant slipping speed and position of sensor relative to the shoe sole and walking direction explained 41% of the fluid pressure variability. Fluid pressures were primarily observed for untreaded conditions. This study confirms that fluid pressures are relevant to slipping events, consistent with fluid dynamics theory (i.e. the Reynolds equation), and can be modified with shoe tread design. The results suggest that the occurrence and severity of unexpected slips can be reduced by designing shoes/floors that reduce underfoot fluid pressures. © 2013 Published by Elsevier Ltd.

  4. Colonic Angiodysplasia with a Huge Submucosal Hematoma in the Sigmoid Colon. (United States)

    Shimizu, Takayuki; Koike, Daisuke; Nomura, Yukihiro; Ooe, Kenji


    Colonic angiodysplasia (AD) with bleeding as a comorbidity in the aging population is being increasingly reported. However, to our knowledge, there is no report on colonic AD accompanied by a huge hematoma. Herein, we report a case of colonic AD with a huge submucosal hematoma. A 75-year-old man with sudden melena was referred to our hospital. Helical computed tomographic angiography (CTA) revealed bleeding from the sigmoid colon. Additionally, colonoscopy showed a huge submucosal hematoma with bleeding in the sigmoid colon. As endoscopic hemostasis was difficult, sigmoidectomy was performed. The pathological diagnosis was colonic AD. The present case indicates that colonic AD should be considered in the differential diagnosis for melena. In addition, the case shows that helical CTA, which is a noninvasive imaging modality, is useful for the diagnosis of colonic AD and is as effective as colonoscopy and angiography for diagnosis.

  5. Robotic resection of huge presacral tumors: case series and comparison with an open resection. (United States)

    Oh, Jae Keun; Yang, Moon Sool; Yoon, Do Heum; Rha, Koon Ho; Kim, Keung Nyun; Yi, Seong; Ha, Yoon


    Clinical case series and analysis. The purpose of the present study is to evaluate the advantages and disadvantages of robotic presacral tumor resection compared with conventional open approach. Conventional open approach for huge presacral tumors in the retroperitoneal space often demands excessive hospitalization and poor cosmesis. Furthermore, narrow surgical field sometimes interrupt delicate procedures. Nine patients with huge (diameter >10 cm) presacral tumors underwent surgery. Five patients among them had robotic procedure and the others had open transperitoneal tumor resection. Operation time, blood loss, hospitalization, and complications were analyzed. Robotic presacral tumor resection showed shorter operation time, less bleeding, and shorter hospitalization. Moreover, there was no complication related to abdominal adhesion. Although robotic resection for presacral tumor still has limitations technically and economically, robotic resection for huge presacral tumors demonstrated advantages over open resection specifically for benign neurogenic tumors.

  6. Giant pulmonary teratoma with huge splenic lymphangiomatosis: a very rare case. (United States)

    Alsubaie, Hemail M; Alsubaie, Khaled M; Mahfouz, Mohammed Eid


    Teratomas are tumors composed of tissues derived from more than one germ cell line. They manifested with a great variety of clinical and radiological features. We report a case of a giant left hemithorax teratoma in a female with huge spleen tumor and review the relevant literature. A 38-year-old female with progressively aggravating dyspnea at rest from a mild trauma. Absent breath sounds on the left side. There was splenomegaly. Computed tomography scan revealed a huge mass (20 × 15 × 18 cm), containing elements of heterogeneous density in the left hemithorax. The spleen tumor was occupying most of the spleen without any other abdominal manifestations. The patient underwent left thoracotomy and laparoscopic splenectomy. Histopathological examination revealed a benign mature teratoma and cystic lymphangiomatosis of the spleen. To the best of our knowledge and after reviewing the available literature this is the first case of huge mature pulmonary teratoma with large cystic spleen lymphangiomatosis.

  7. Huge splenic epidermoid cyst with elevation of serum CA19-9 level. (United States)

    Matsumoto, Sayo; Mori, Toshifumi; Miyoshi, Jinsei; Imoto, Yoshitaka; Shinomiya, Hirohiko; Wada, Satoshi; Nakao, Toshihiro; Shinohara, Hisamitsu; Yoshida, Sadahiro; Izumi, Keisuke; Okazaki, Jun; Muguruma, Naoki; Takayama, Tetsuji


    A 30-year-old female was referred to our hospital for further examination of liver dysfunction. A huge, soft mass was noted in her left upper quadrant on physical examination. Abdominal ultrasonography and computed tomography revealed a huge cystic tumor of 20 cm in the hilus of the spleen. Serum CA19-9 was 491 U/ml, and splenectomy was performed under suspicion of a malignant cystic tumor. The inner surface of the cyst was lined by squamous epithelial cells that were immunohistochemically positive for CA19-9. Serum CA19-9 level was normalized after the surgery. Our case of a very rare, huge epidermoid cyst of the spleen suggests that measurement of the serum CA19-9 level is useful for evaluating therapeutic efficacy of a splenic epidermoid cyst.

  8. Endovascular Treatment of a Huge Hepatic Artery Aneurysm by Coil Embolization Method: A Case Report. (United States)

    Hemmati, Hossein; Karimian, Mehdi; Moradi, Habibollah; Farid Marandi, Kambiz; Haghdoost, Afrooz


    Hepatic artery aneurysms are rare but potentially life threatening. We describe a novel case of a successful endovascular coil embolization of a huge hepatic artery aneurysm. A 67-year-old woman presented with recent abdominal pain that had begun from 2 weeks before referring to our hospital. Sonographic and computerized tomographic (CT) findings revealed a huge hepatic artery aneurysm with 95 mm × 83 mm diameter. The patient underwent an endovascular technique. In aortic angiography, the celiac artery orifice and superior mesenteric artery were so narrow, so sonography was used in order to determine the exact position of the catheter in the celiac artery orifice. The aneurysm was thrombosed using coil embolization. Pulsation of the aneurysm immediately disappeared. Huge hepatic artery aneurysm can be safely treated using coil embolization.

  9. Collaborative treatment of huge intrathoracic meningoceles associated with neurofibromatosis type 1: a case report. (United States)

    Cho, Deog Gon; Chang, Yong Jin; Cho, Kyu Do; Hong, Jae Taek


    An intrathoracic meningocele is a relatively rare disease, and it commonly accompanies neurofibromatosis type 1. Patients tend to have no symptom but if its size is too large and compresses a lung and neighboring organs, it needs shunt drainage or surgical resection. Herein, we present the case of a 52 year-old female patient with huge intrathoracic meningoceles associated with neurofibromatosis type 1, who has complained about chest discomfort and dyspnea at rest. As for a preliminary treatment, a neurosurgeon had performed a cystoperitoneal shunt, but the symptoms continued and the size of mass and the amount of pleural effusion did not change significantly. Therefore, the huge thoracic meningoceles were successfully treated through the thoracotomic approach in combination with lumbar puncture and cerebrospinal fluid drainage. It is reported that double huge intrathoracic meningoceles associated with neurofibromatosis type 1 was successfully treated by a shunting procedure followed by thoracotomic resection with collaboration of a neurosurgeon.

  10. Frictional Behavior and Slip Localization in Simulated Faults of Halite at Sub-seismic to Seismic Slip Rates (United States)

    Kim, J.; Ree, J.; Han, R.; Shimamoto, T.


    Halite exhibits deformation behavior ranging from brittle to plastic at room temperature and at low pressures, and has been used to simulate deformation processes of the brittle-ductile transition zone. However, previous experiments on halite were performed at very low slip rates (10-9-10-3 m/s), requiring friction data at seismic slip rates for a more complete assessment of the applicability of the experimental results to natural earthquakes. We conducted friction experiments on halite at slip rate of 0.02-1.3 m/s and normal stresses of 0.8- 10.0 MPa using a high-velocity rotary shear apparatus. A thin layer (0.6-1.0 mm thick) of halite gouge was inserted between precut rock cylinders jacketed with Teflon sleeve. We found that mechanical behavior and deformation processes of halite gouge are remarkably different depending on slip rate and that frictional melting and dislocation creep can occur simultaneously at seismic slip rates. At sub-seismic slip rates of 0.02 to 0.05 m/sec, peak friction (μp = 0.76-0.85) was followed by steady-state friction (μss = 0.35-0.37). Gouge layer consists of a thin slip localization zone at the halite gouge-rock contact and a thick low slip-rate zone. The low slip-rate zone shows evidence for cataclastic flow with angular fragments set in a fine matrix. In contrast, the slip localization zone consists of very fine gouge with some remnants of fragments. At seismic slip rates of 0.1 to 1.3 m/sec, μp (0.64-0.99) was followed by μss (0.36-0.03). μss decreases with increasing slip rate. The shear zone consists of a thin slip localization zone at the halite gouge-rock contact and a thick low slip-rate zone. The low slip-rate zone consists of polycrystalline halite ribbons highly elongated obliquely to shear zone boundary and the oblique foliation is dragged into the thin slip localization zone. Each ribbon is also defined as a lattice preferred orientation domain by electron back-scattered diffraction (EBSD) analysis. Individual

  11. Surface fault slip associated with the 2004 Parkfield, California, earthquake (United States)

    Rymer, M.J.; Tinsley, J. C.; Treiman, J.A.; Arrowsmith, J.R.; Ciahan, K.B.; Rosinski, A.M.; Bryant, W.A.; Snyder, H.A.; Fuis, G.S.; Toke, N.A.; Bawden, G.W.


    Surface fracturing occurred along the San Andreas fault, the subparallel Southwest Fracture Zone, and six secondary faults in association with the 28 September 2004 (M 6.0) Parkfield earthquake. Fractures formed discontinuous breaks along a 32-km-long stretch of the San Andreas fault. Sense of slip was right lateral; only locally was there a minor (1-11 mm) vertical component of slip. Right-lateral slip in the first few weeks after the event, early in its afterslip period, ranged from 1 to 44 mm. Our observations in the weeks following the earthquake indicated that the highest slip values are in the Middle Mountain area, northwest of the mainshock epicenter (creepmeter measurements indicate a similar distribution of slip). Surface slip along the San Andreas fault developed soon after the mainshock; field checks in the area near Parkfield and about 5 km to the southeast indicated that surface slip developed more than 1 hr but generally less than 1 day after the event. Slip along the Southwest Fracture Zone developed coseismically and extended about 8 km. Sense of slip was right lateral; locally there was a minor to moderate (1-29 mm) vertical component of slip. Right-lateral slip ranged from 1 to 41 mm. Surface slip along secondary faults was right lateral; the right-lateral component of slip ranged from 3 to 5 mm. Surface slip in the 1966 and 2004 events occurred along both the San Andreas fault and the Southwest Fracture Zone. In 1966 the length of ground breakage along the San Andreas fault extended 5 km longer than that mapped in 2004. In contrast, the length of ground breakage along the Southwest Fracture Zone was the same in both events, yet the surface fractures were more continuous in 2004. Surface slip on secondary faults in 2004 indicated previously unmapped structural connections between the San Andreas fault and the Southwest Fracture Zone, further revealing aspects of the structural setting and fault interactions in the Parkfield area.

  12. Huge Bilateral Paramesonephric Cysts in a 25 year old Nulliparous woman (United States)

    Sagili, Haritha; Krishnan, Manikandan; Dasari, Papa


    Paraovarian cysts are uncommon adnexal masses which are usually asymptomatic. We describe a case of bilateral huge paramesonephric cysts in a nulliparous woman. A 25-year-old lady presented with abdominal distension for one year duration. Examination and imaging revealed large abdominopelvic cystic masses with no solid areas or septations. Intraoperatively there were huge bilateral paraovarian cysts which were excised. Histopathology revealed low cuboidal to ciliated columnar epithelium with no evidence of ovarian parenchyma suggestive of paramesonephric cyst. Paraovarian cyst should be included in the differential diagnosis of a cystic mass visualised on ultrasound. PMID:24392412

  13. Huge dissected ascending aorta associated with pseudo aneurysm and aortic coarctation feridoun. (United States)

    Sabzi, Feridoun; Khosravi, Donya


    We report a unique case of chronic dissection of the ascending aorta complicated with huge and thrombotic pseudoaneurysm in a patient with coarctation of descending aorta. Preoperative investigations such as transesophageal echocardiography (TEE) confirmed the diagnosis of dissection. Intraoperative findings included a12 cm eccentric bulge of the right lateral side of dilated the ascending aorta filled with the clot and a circular shaped intimal tear communicating with an extended hematoma and dissection of the media layer. The rarity of the report is an association of the chronic dissection with huge pseudoaneurysm and coarctation. The patient underwent staged repair of an aneurysm and coarctation and had an uneventful postoperative recovery period.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hsiung, L; La Cruz, C


    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

  15. Theoretical Proposals of Quantum Phase-slip Devices

    NARCIS (Netherlands)

    Hriscu, A.M.


    This thesis describes a series of theoretical proposals of novel circuits that embed ultrathin superconducting nanowires with coherent quantum phase-slips (QPS). The motivation for our proposals is twofold: firstly, to facilitate unambiguous experimental verification of coherent phase-slips. Secondl

  16. Friction and stick-slip in a telescope construction

    NARCIS (Netherlands)

    Hammerschlag, R.H.


    Stick-slip in high resolution telescopes should be avoided. The contact places where stick-slip can occur are described. Some contact places require a high friction coefficient, others a low friction coefficient. Some experiments have been carried out to find lubricants for contact places which comb

  17. Slipping and rolling on an inclined plane

    Energy Technology Data Exchange (ETDEWEB)

    Aghamohammadi, Cina [Department of Electrical Engineering, Sharif University of Technology, PO Box 11365-11155, Tehran (Iran, Islamic Republic of); Aghamohammadi, Amir, E-mail: [Department of Physics, Alzahra University, Tehran 19938-91176 (Iran, Islamic Republic of)


    In the first part of the paper, using a direct calculation two-dimensional motion of a particle sliding on an inclined plane is investigated for general values of friction coefficient ({mu}). A parametric equation for the trajectory of the particle is also obtained. In the second part of the paper, the motion of a sphere on the inclined plane is studied. It is shown that the evolution equation for the contact point of a sliding sphere is similar to that of a point particle sliding on an inclined plane whose friction coefficient is 7/2 {mu}. If {mu} > 2/7 tan {theta}, for any arbitrary initial velocity and angular velocity, the sphere will roll on the inclined plane after some finite time. In other cases, it will slip on the inclined plane. In the case of rolling, the centre of the sphere moves on a parabola. Finally the velocity and angular velocity of the sphere are exactly computed.

  18. Slip Effects in Compressible Turbulent Channel Flow

    CERN Document Server

    Skovorodko, P A


    The direct numerical simulation of compressible fully developed turbulent Couette flow between two parallel plates with equal temperatures moving in opposite directions with some velocity was performed. The algorithm was tested on well known numerical solution for incompressible Poiseuille channel flow and found to provide its well description. The slip effects in studied flow are found to be negligibly small at the values of accommodation coefficients for velocity and temperature of the order of unity. The considerable increase of mean temperature with decreasing the accommodation coefficient for temperature was discovered. The effect may be important in the problems of heat exchange in compressible turbulent boundary layer for some combinations of flowing gas, surface and adsorbing gas.

  19. Slip effects in compressible turbulent channel flow (United States)

    Skovorodko, P. A.


    The direct numerical simulation of compressible fully developed turbulent Couette flow between two parallel plates with temperature Tw moving with velocities ±Uw was performed. The algorithm was tested on well known numerical solution for incompressible Poiseuille channel flow and found to provide its well description. The slip effects in studied flow are found to be negligibly small at the values of accommodation coefficients αu and αT of the order of unity. The considerable increase of mean temperature with decreasing the accommodation coefficient αT for fixed value of αu = 1 was discovered. The effect may be important in the problems of heat exchange in compressible turbulent boundary layer for some combinations of flowing gas, surface and adsorbing gas.

  20. Slipping and Rolling on an Inclined Plane

    CERN Document Server

    Aghamohammadi, Cina; 10.1088/0143-0807/32/4/017


    In the first part of the article using a direct calculation two-dimensional motion of a particle sliding on an inclined plane is investigated for general values of friction coefficient ($\\mu$). A parametric equation for the trajectory of the particle is also obtained. In the second part of the article the motion of a sphere on the inclined plane is studied. It is shown that the evolution equation for the contact point of a sliding sphere is similar to that of a point particle sliding on an inclined plane whose friction coefficient is $2/7}\\ \\mu$. If $\\mu> 2/7 \\tan\\theta$, for any arbitrary initial velocity and angular velocity the sphere will roll on the inclined plane after some finite time. In other cases, it will slip on the inclined plane. In the case of rolling center of the sphere moves on a parabola. Finally the velocity and angular velocity of the sphere are exactly computed.

  1. Slipped capital femoral epiphysis in down syndrome. (United States)

    Dietz, Frederick R; Albanese, Stephen A; Katz, Danielle A; Dobbs, Matthew B; Salamon, Peter B; Schoenecker, Perry L; Sussman, Michael D


    Slipped capital femoral epiphysis (SCFE) and Down syndrome are both uncommon in the population at large, and rarely are both conditions present in a single individual. Institutional records were searched for both Down syndrome and SCFE. At least 2 years of follow-up was required. Eight patients were identified. At presentation four patients could not walk due to pain and four could walk. Six of eight hips presented with grade III SCFE. Four hips were treated with internal fixation in situ and four were manipulatively reduced in the operating room at the time of fixation with percutaneous screws or pins. Three hips healed uneventfully. Five hips developed aseptic necrosis (three partial, two whole head). This small retrospective study suggests an extremely high rate of complications in adolescents with Down syndrome and SCFE.

  2. Slipped upper femoral epiphysis with hemophilia A

    Directory of Open Access Journals (Sweden)

    Iyer Deepa


    Full Text Available A 13-year-old boy who had hemophilia A was reported with pain in the left thigh and hip on walking. He had no history of trauma. Severe hemophilia A is diagnosed with a Factor VIII level of < 1 iu/dl. The presumptive diagnosis was that of a spontaneous bleed into the hip joint. Factor VIII mutational analysis revealed a C to G substitution at nucleotide 6683 which results in a cystine change at codon 2194. However, the symptoms persisted and an X-ray demonstrated the presence of an acute on chronic slip of the upper femoral epiphysis. The patient was transferred to the center treating his hemophilia where the hip was pinned in situ under cover with Factor VIII. This case demonstrates the need to be aware of a possible traumatic diagnosis of hip pain in a hemophiliac child with a longstanding history of spontaneous bleeding into joints.

  3. Quantifying effective slip length over micropatterned hydrophobic surfaces

    CERN Document Server

    Tsai, Peichun; Pirat, Christophe; Wessling, Matthias; Lammertink, Rob G H; Lohse, Detlef


    We employ micro-particle image velocimetry ($\\mu$-PIV) to investigate laminar micro-flows in hydrophobic microstructured channels, in particular the slip length. These microchannels consist of longitudinal micro-grooves, which can trap air and prompt a shear-free boundary condition and thus slippage enhancement. Our measurements reveal an increase of the slip length when the width of the micro-grooves is enlarged. The result of the slip length is smaller than the analytical prediction by Philip et al. [1] for an infinitely large and textured channel comprised of alternating shear-free and no-slip boundary conditions. The smaller slip length (as compared to the prediction) can be attributed to the confinement of the microchannel and the bending of the meniscus (liquid-gas interface). Our experimental studies suggest that the curvature of the meniscus plays an important role in microflows over hydrophobic micro-ridges.

  4. The experimentalanalysis of the slip in the rubber belt CVT (United States)

    Grzegożek, W.; Kot, A.


    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.

  5. The Slip Hypothesis: Tactile Perception and its Neuronal Bases. (United States)

    Schwarz, Cornelius


    The slip hypothesis of epicritic tactile perception interprets actively moving sensor and touched objects as a frictional system, known to lead to jerky relative movements called 'slips'. These slips depend on object geometry, forces, material properties, and environmental factors, and, thus, have the power to incorporate coding of the perceptual target, as well as perceptual strategies (sensor movement). Tactile information as transferred by slips will be encoded discontinuously in space and time, because slips sometimes engage only parts of the touching surfaces and appear as discrete and rare events in time. This discontinuity may have forced tactile systems of vibrissae and fingertips to evolve special ways to convert touch signals to a tactile percept.

  6. Proposed Cavity for Reduced Slip-Stacking Loss

    Energy Technology Data Exchange (ETDEWEB)

    Eldred, J. [Indiana U.; Zwaska, R. [Fermilab


    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.

  7. Effect of slip on circulation inside a droplet

    CERN Document Server

    Thalakkottor, Joseph J


    Internal recirculation in a moving droplet plays an important role in several droplet-based microfluidic devices as it enhances mixing, chemical reaction and heat transfer. The occurrence of fluid slip at the wall, which becomes prominent at high shear rates and lower length scales, results in a significant change in droplet circulation. Using molecular dynamics (MD) simulations, the presence of circulation in droplets is demonstrated and quantified. Circulation is shown to vary inversely with slip length, which is a measure of interface wettability. A simple circulation model is established that captures the effect of slip on droplet circulation. Scaling parameters for circulation and slip length are identified from the circulation model which leads to the collapse of data for droplets with varying aspect ratio (AR) and slip length. The model is validated using continuum and MD simulations and is shown to be accurate for droplets with high AR.

  8. Thermal slip for liquids at rough solid surfaces (United States)

    Zhang, Chengbin; Chen, Yongping; Peterson, G. P.


    Molecular dynamics simulation is used to examine the thermal slip of liquids at rough solid surfaces as characterized by fractal Cantor structures. The temperature profiles, potential energy distributions, thermal slip, and interfacial thermal resistance are investigated and evaluated for a variety of surface topographies. In addition, the effects of liquid-solid interaction, surface stiffness, and boundary condition on thermal slip length are presented. Our results indicate that the presence of roughness expands the low potential energy regions in adjacent liquids, enhances the energy transfer at liquid-solid interface, and decreases the thermal slip. Interestingly, the thermal slip length and thermal resistance for liquids in contact with solid surfaces depends not only on the statistical roughness height, but also on the fractal dimension (i.e., topographical spectrum).

  9. Numerical Investigations of Slip Phenomena in Centrifugal Compressor Impellers (United States)

    Huang, Jeng-Min; Luo, Kai-Wei; Chen, Ching-Fu; Chiang, Chung-Ping; Wu, Teng-Yuan; Chen, Chun-Han


    This study systematically investigates the slip phenomena in the centrifugal air compressor impellers by CFD. Eight impeller blades for different specific speeds, wrap angles and exit blade angles are designed by compressor design software to analyze their flow fields. Except for the above three variables, flow rate and number of blades are the other two. Results show that the deviation angle decreases as the flow rate increases. The specific speed is not an important parameter regarding deviation angle or slip factor for general centrifugal compressor impellers. The slip onset position is closely related to the position of the peak value in the blade loading factor distribution. When no recirculation flow is present at the shroud, the variations of slip factor under various flow rates are mainly determined by difference between maximum blade angle and exit blade angle, Δβmax-2. The solidity should be of little importance to slip factor correlations in centrifugal compressor impellers.

  10. Stick-slip substructure in rapid tape peeling

    KAUST Repository

    Thoroddsen, Sigurdur T.


    The peeling of adhesive tape is known to proceed with a stick-slip mechanism and produces a characteristic ripping sound. The peeling also produces light and when peeled in a vacuum, even X-rays have been observed, whose emissions are correlated with the slip events. Here we present direct imaging of the detachment zone when Scotch tape is peeled off at high speed from a solid surface, revealing a highly regular substructure, during the slip phase. The typical 4-mm-long slip region has a regular substructure of transverse 220 μm wide slip bands, which fracture sideways at speeds over 300 m/s. The fracture tip emits waves into the detached section of the tape at ∼100 m/s, which promotes the sound, so characteristic of this phenomenon.

  11. Polydimethylsiloxane SlipChip for mammalian cell culture applications. (United States)

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


    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.

  12. Preslip and cascade processes initiating laboratory stick slip (United States)

    McLaskey, Gregory C.; Lockner, David A.


    Recent modeling studies have explored whether earthquakes begin with a large aseismic nucleation process or initiate dynamically from the rapid growth of a smaller instability in a "cascade-up" process. To explore such a case in the laboratory, we study the initiation of dynamic rupture (stick slip) of a smooth saw-cut fault in a 76 mm diameter cylindrical granite laboratory sample at 40-120 MPa confining pressure. We use a high dynamic range recording system to directly compare the seismic waves radiated during the stick-slip event to those radiated from tiny (M -6) discrete seismic events, commonly known as acoustic emissions (AEs), that occur in the seconds prior to each large stick slip. The seismic moments, focal mechanisms, locations, and timing of the AEs all contribute to our understanding of their mechanics and provide us with information about the stick-slip nucleation process. In a sequence of 10 stick slips, the first few microseconds of the signals recorded from stick-slip instabilities are nearly indistinguishable from those of premonitory AEs. In this sense, it appears that each stick slip begins as an AE event that rapidly (~20 µs) grows about 2 orders of magnitude in linear dimension and ruptures the entire 150 mm length of the simulated fault. We also measure accelerating fault slip in the final seconds before stick slip. We estimate that this slip is at least 98% aseismic and that it both weakens the fault and produces AEs that will eventually cascade-up to initiate the larger dynamic rupture.

  13. Endovascular repair for a huge vertebral artery pseudoaneurysm caused by Behcet's disease

    Institute of Scientific and Technical Information of China (English)

    DONG Zhi-hui; FU Wei-guo; GUO Da-qiao; XU Xin; CHEN Bin; JIANG Jun-hao; YANG Jue; SHI Zheng-yu; WANG Yu-qi


    @@ Behcet's disease (BD), a multisystem chronic autoimmune process of unknown etiology,usually leads to arterial impairment. Isolated case reports have described BD-related arterial dissections, pseudoaneurysms or aneurysms.1-4 Recently, we successfully treated a huge vertebral artery pseudoaneurysm (VAPA) in a patient with BD by stent-grafting with preservation of the affected vertebral artery.

  14. Unusual Huge Keratoacanthoma in Sites of in the Previous Split-Thickness Skin Grafted Area

    Directory of Open Access Journals (Sweden)

    Fatih Uygur


    Full Text Available Keratoacanthoma (KA is a fairly common keratinizing, squamous neoplasm. The exact etiology of KA is unknown. However, ultraviolet radiation, trauma, chemical carcinogens, viral infections, immunosuppression, genetic factors, radiation and thermal burns have been accused of pathogenesis. In here, we represent an unusual huge KA arising from the previous reconstructed with split-thickness skin graft on the dorsal foot.

  15. Constructing Optimal Coarse-Grained Sites of Huge Biomolecules by Fluctuation Maximization. (United States)

    Li, Min; Zhang, John Zenghui; Xia, Fei


    Coarse-grained (CG) models are valuable tools for the study of functions of large biomolecules on large length and time scales. The definition of CG representations for huge biomolecules is always a formidable challenge. In this work, we propose a new method called fluctuation maximization coarse-graining (FM-CG) to construct the CG sites of biomolecules. The defined residual in FM-CG converges to a maximal value as the number of CG sites increases, allowing an optimal CG model to be rigorously defined on the basis of the maximum. More importantly, we developed a robust algorithm called stepwise local iterative optimization (SLIO) to accelerate the process of coarse-graining large biomolecules. By means of the efficient SLIO algorithm, the computational cost of coarse-graining large biomolecules is reduced to within the time scale of seconds, which is far lower than that of conventional simulated annealing. The coarse-graining of two huge systems, chaperonin GroEL and lengsin, indicates that our new methods can coarse-grain huge biomolecular systems with up to 10,000 residues within the time scale of minutes. The further parametrization of CG sites derived from FM-CG allows us to construct the corresponding CG models for studies of the functions of huge biomolecular systems.

  16. Anatomic trisegmentectomy: An alternative treatment for huge or multiple hepatocellular carcinoma of right liver. (United States)

    Jia, Changku; Weng, Jie; Qin, Qifan; Chen, Youke; Huang, Xiaolong; Fu, Yu


    The patients with huge (≥10cm) or multiple hepatocellular carcinoma (HCC) in the right liver and insufficient size of the remnant left liver can not be performed an operation of right hemihepatectomy because of that liver failure will occur post operation. We designed anatomic trisegmentectomy in right liver to increase the ratio of future liver remnant volume (%FLRV), thus increasing resectability of huge or multiple HCC. Thirteen patients were analyzed by preoperative CT scan for liver and tumor volumetries. If the right hemihepatectomy was done, %FLRV would be at the range of 29.6%-37.5%. However, if trisegmentectomy was done, %FLRV would increase by an average of 14.0%. So patients will not undergo postoperative liver failure due to sufficient %FLRV. Therefore, we designed anatomic trisegmentectomy, with retention of segment 5 or segment 8, to increase %FLRV and increase the resectability for huge or multiple HCC. After trisegmentectomy, the inflow and outflow of remnant liver were maintained well. Severe complications and mortality were not happened post operation. Of the 13 patients, 10 survived up to now. Of the 10 living cases, postoperative lung metastasis was found in 2 and intrahepatic recurrence was found in 1. These 3 patients survive with tumor after comprehensive therapies including oral administration of Sorafenib. Compared to right hemihepatectomy, anatomic trisegmentectomy in right liver guarantees the maximum preservation of %FLRV to increase the resectability of huge or multiple HCC, thus improving the overall resection rate. Copyright © 2017. Published by Elsevier Masson SAS.

  17. Huge hepatocellular carcinoma with multiple intrahepatic metastases: An aggressive multimodal treatment. (United States)

    Yasuda, Satoshi; Nomi, Takeo; Hokuto, Daisuke; Yamato, Ichiro; Obara, Shinsaku; Yamada, Takatsugu; Kanehiro, Hiromichi; Nakajima, Yoshiyuki


    Huge hepatocellular carcinoma (HCC) possesses a potential risk for spontaneous rupture, which leads to a life-threatening complication with a high mortality rate. In addition, a large HCC is frequently accompanied by intrahepatic metastases. We describe, the case of a 74-year-old woman with a huge extrahepatically expanding HCC with multiple intrahepatic metastases who was treated by liver resection with repeated transcatheter arterial chemoembolization (TACE). To prevent tumor rupture or bleeding, we performed right hepatectomy. After the operation, TACE was applied for multiple intrahepatic metastases in the remnant liver. Furthermore, the elevated protein induced vitamin K absence (PIVKA II) level had decreased to limits within the normal range. Three months after the first TACE, computed tomography revealed several recurrences in the liver. TACE was applied for the second and third time and the tumors were well controlled. Although, liver resection is occasionally performed for patients with huge HCC to avoid spontaneous tumor rupture, only surgical approach might not be sufficient for such advanced HCC. To achieve long-term survival, it is necessary to control the residual intrahepatic tumors. We could control multiple intrahepatic metastases with repeated TACEs after hepatectomy. Multimodal treatment involving hepatectomy and TACE might be a good treatment strategy for patients with huge HCC with multiple intrahepatic metastases if the tumors are localized in the liver without distant or peritoneal metastasis. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. Hepatic arterial infusion chemotherapy for patients with huge unresectable hepatocellular carcinoma. (United States)

    Tsai, Wei-Lun; Lai, Kwok-Hung; Liang, Huei-Lung; Hsu, Ping-I; Chan, Hoi-Hung; Chen, Wen-Chi; Yu, Hsien-Chung; Tsay, Feng-Woei; Wang, Huay-Min; Tsai, Hung-Chih; Cheng, Jin-Shiung


    The optimal treatment for huge unresectable hepatocellular carcinoma (HCC) remains controversial. The outcome of transcatheter arterial chemoembolization (TACE) for patients huge unresectable HCC is generally poor and the survival benefit of TACE in these patients is unclear. The aim of the study is to compare the effect of hepatic arterial infusion chemotherapy (HAIC) versus symptomatic treatment in patients with huge unresectable HCC. Since 2000 to 2005, patients with huge (size >8 cm) unresectable HCC were enrolled. Fifty-eight patients received HAIC and 44 patients received symptomatic treatment. In the HAIC group, each patient received 2.4+1.4 (range: 1-6) courses of HAIC. Baseline characteristics and survival were compared between the HAIC and symptomatic treatment groups. The HAIC group and the symptomatic treatment group were similar in baseline characteristics and tumor stages. The overall survival rates at one and two years were 29% and 14% in the HAIC group and 7% and 5% in the symptomatic treatment group, respectively. The patients in the HAIC group had significantly better overall survival than the symptomatic treatment group (Phuge unresectable HCC.

  19. A Computational Method for Enabling Teaching-Learning Process in Huge Online Courses and Communities (United States)

    Mora, Higinio; Ferrández, Antonio; Gil, David; Peral, Jesús


    Massive Open Online Courses and e-learning represent the future of the teaching-learning processes through the development of Information and Communication Technologies. They are the response to the new education needs of society. However, this future also presents many challenges such as the processing of online forums when a huge number of…

  20. A Huge Subcutaneous Hematoma in an Adult with Kasabach-Merritt Syndrome. (United States)

    Wu, Kuan-Lin; Liao, Chiung-Ying; Chang, Chen-Kuang; Ho, Shang-Yun; Tyan, Yeu-Sheng; Huang, Yuan-Chun


    BACKGROUND Kasabach-Merritt syndrome is a potentially fatal disease that consists of hemangioma(s) with thrombocytopenia, microangiopathic hemolytic anemia, and coagulopathy. Extensive hemangiomatosis is rare. We present the radiological features and treatment strategy of a young adult suffering from Kasabach-Merritt syndrome with widespread hemangiomas and an infected huge hematoma in the right thigh. CASE REPORT A 33-year-old Taiwanese male presented with a painful 20-cm mass over his right thigh and gross hematuria for 2 days. Hemangiomatosis was bioptically proven in infancy and the patient was under regular follow-up. Physical examination revealed normal heart rate, respiratory rate, and body temperature. Multiple palpable lumps with brown and purple areas of skin over the neck, trunk, and right thigh were noted. Laboratory examinations revealed thrombocytopenia anemia and elevated fibrin degradation products. There were no signs of sepsis. Blood transfusion and steroid therapy were executed. Computed tomography showed a huge complicated subcutaneous hematoma in the right thigh. Drainage of the huge hematoma was performed and antibiotics were prescribed. After the local infection in the right thigh and the bleeding tendency were controlled, the patient was discharged in a stable condition two weeks later. CONCLUSIONS A huge infected hematoma and widespread hemangiomas are extremely rare complications of Kasabach-Merritt syndrome. There are no known treatment guidelines currently available. Our patient was successfully treated with steroids, drainage, and antibiotics.

  1. A Huge Ovarian Cyst in a Middle-Aged Iranian Female

    Directory of Open Access Journals (Sweden)

    Mohammad Kazem Moslemi


    Full Text Available A 38-year-old Iranian woman was found to have a huge ovarian cystic mass. Her presenting symptom was vague abdominal pain and severe abdominal distention. She underwent laparotomy and after surgical removal, the mass was found to be mucinous cystadenoma on histology.

  2. Huge right atrial myxoma causing fixed tricuspid stenosis with constitutional symptoms. (United States)

    Kuralay, Erkan; Cingöz, Faruk; Günay, Celalettin; Demirkiliç, Ufuk; Tatar, Harun


    Nonspecific constitutional symptoms are reported mostly in patients with left-atrial myxomas, which occur five times as often as its right-atrial counterpart. We present huge right-atrial myxoma, which obstructs tricuspid orifice with nonspecific constitutional symptoms without any pulmonary embolism attack.

  3. Preserving stability of huge agriculture machines with internal mobilities: Application to a grape harvester


    Dieumet, D.; Thuilot, B.; Lenain, R.; Berducat, M.


    International audience; This paper proposes an algorithm for estimating on-line the rollover risk of huge machine moving on natural ground. The approach is based on the reconstruction of lateral load transfer thanks to an observer, able to take into account terrain specificities (grip conditions and geometry). Capabilities are tested through experiments on a grape harvester.

  4. Constitutive relations between dynamic physical parameters near a tip of the propagating slip zone during stick-slip shear failure (United States)

    Ohnaka, Mitiyasu; Kuwahara, Yasuto; Yamamoto, Kiyohiko


    Constitutive relations between physical parameters in the cohesive zone during stick-slip shear failure are experimentally investigated. Stick-slip was generated along a 40 cm long precut fault in Tsukuba granite samples using a servocontrolled biaxial loading apparatus. Dynamic behavior during local breakdown processes near a tip of the slipping zone is revealed; the slip velocity and acceleration are given as a function of the slip displacement and the cohesive (or breakdown) shear stress as a function of the slip velocity. A cycle of the breakdown and restrengthening process of stick-slip is composed of five phases characterized in terms of the cohesive strength and the slip velocity. The cohesive strength can degrade regardless of the slip velocity during slip instabilities. The maximum slip acceleration ümax and the maximum slip velocity u˙max are obtained experimentally as: ümax= {2}/{u cu˙max2}andu˙max= {Δτ b}/{G}v where u c is the critical displacement, Δτb the breakdown stress drop, G the rigidity and v the rupture velocity. These relations are consistent with Ida's theoretical estimation based on the cohesive zone model. The above formula gives good estimates for the maximum slip acceleration of actual earthquakes. The cutoff frequency ƒ maxof the power spectral density of the slip acceleration increases with increasing normal stress; in particular, ƒ maxis found to be directly proportional to the normal stress σn within the normal stress range less than 17 MPa as: ƒ max(kHz) = 4.0σ n(MPa) σn<17(MPa) ƒ maxincrease with an increase in u˙max or ümax. All these results lead to the conclusion that ümax, u˙max and ƒ max increase with increasing normal stress. This is consistent with a previous observation that τb increases with increasing normal stress. The above empirical linear relation between ƒ max and σn can be explained by a linear dependence of Δτb on σn. The size-scale dependence of physical parameters is discussed, and such

  5. Biliary obstruction due to a huge simple hepatic cyst treated with laparoscopic resection. (United States)

    Kaneya, Yohei; Yoshida, Hiroshi; Matsutani, Takeshi; Hirakata, Atsushi; Matsushita, Akira; Suzuki, Seiji; Yokoyama, Tadashi; Maruyama, Hiroshi; Sasajima, Koji; Uchida, Eiji


    Most hepatic cysts are asymptomatic, but complications occasionally occur. We describe a patient with biliary obstruction due to a huge simple hepatic cyst treated with laparoscopic resection. A 60-year-old Japanese woman was admitted to our hospital because of a nontender mass in the right upper quadrant of the abdomen. Laboratory tests revealed the following: serum total bilirubin, 0.6 mg/dL; serum aspartate aminotransferase, 100 IU/L; serum alanine aminotransferase, 78 IU/L; serum alkaline phosphatase, 521 IU/L; and serum gamma glutamic transpeptidase, 298 IU/L. Abdominal computed tomography, ultrasonography, and magnetic resonance cholangiopancreatography revealed a huge hepatic cyst, 13 cm in diameter, at the hepatic hilum, accompanied by dilatation of the intrahepatic bile duct and obstruction of the common bile duct. We diagnosed biliary obstruction due to a huge hepatic cyst at the hepatic hilum, and laparoscopic surgery was performed. A huge hepatic cyst was seen at the hepatic hilum. After needle puncture of the huge cyst, the anterior wall of the cyst was unroofed, and cholecystectomy was done. Intraoperative cholangiography through a cystic duct revealed stenosis of the duct. Subsequent decapsulation of the cyst was performed in front of the common bile duct. After this procedure, cholangiography revealed that the stenosis of the common bile duct had resolved. Histopathological examination of the surgical specimen confirmed the hepatic cyst was benign. The postoperative course was uneventful, and the results of liver function tests normalized. The patient was discharged 7 days after operation. Computed tomography 3 months after operation revealed disappearance of the hepatic cyst and no dilatation of the intrahepatic bile duct.

  6. Loading and texture bias on the competitive slip activity for basal and prismatic slip systems in HCP alloys (United States)

    Saxena, A. K.; Tewari, A.; Pant, P.


    Asymmetry in hexagonal crystal structure makes the occurrence of slip strongly dependent on the texture of sample. In titanium, which has a c/a ratio less than ideal, slip occurs preferentially on prismatic slip system. However other slip systems may get activated depending on the resolved shear stresses. In this paper we present results from plane strain compression experiments where the same area of the sample was imaged before and after deformation to document changes in microstructure. We then compare these results with a simple calculation of plastic strain based on activation of various slip systems depending on their respective critical resolved shear stresses. We show that incorporation of a strain rate dependent hardening parameter provides a reasonable match with the experimentally observed deformation behaviour of various grain orientations.

  7. Observations of premonitory acoustic emission and slip nucleation during a stick slip experiment in smooth faulted Westerly granite (United States)

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


    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.

  8. Slip-behavior transitions of a heterogeneous linear fault (United States)

    Yabe, S.; Ide, S.


    Shear-slip behavior on the fault has diversity, such as ordinary earthquakes, afterslips, and shallow and deep slow earthquakes. Although the cause of this diversity is a hot topic in seismology, one possibility is the friction varying with tectonic environments (e.g., Blanpied et al., 1991). It is often explained that negative, neutral, and positive a-b of rate and state friction law corresponds to seismogenic zone, slow earthquake, and creeps in subduction zones, respectively. However, the frictional heterogeneity is expected to exist on the fault because of the fractal irregular fault surface in a wide scale range (Candela et al., 2012), which fluctuate rupture propagations. To understand the slip behavior of such heterogeneous fault, we have conducted the simplest numerical simulations with an infinite linear fault embedded in the 2D elastic medium, on which frictional parameters have cyclic bimodal distributions. As a result, we have observed several types of slip behavior changing with the density of velocity weakening zone (VWZ) on the fault. At low densities with VWZ smaller than the nucleation size (Rubin and Ampuero, 2005), the fault slips stably. At medium densities, where the spatial average of a-b is positive, seismic slip occurs in VWZ followed by an afterslip in velocity-strengthening zone (VSZ). At high densities where the spatial average of a-b is negative, the entire fault including VSZ slips seismically. When the spatial average of a-b is close to zero, the transitional behavior is observed, in which seismic slip in VWZ and fast aseismic slip in VSZ are strongly interacted, and relatively slower deformation dominates. We also provide some examples with more complex distributions of frictional parameter to explore the possibility that the frictional heterogeneity may explain not only the diverse seismic phenomena, but also the scaling of slip weakening distance of ordinary earthquakes.

  9. Simulation of the frictional stick-slip instability (United States)

    Mora, Peter; Place, David


    A lattice solid model capable of simulating rock friction, fracture and the associated seismic wave radiation is developed in order to study the origin of the stick-slip instability that is responsible for earthquakes. The model consists of a lattice of interacting particles. In order to study the effect of surface roughness on the frictional behavior of elastic blocks being rubbed past one another, the simplest possible particle interactions were specified corresponding to radially dependent elastic-brittle bonds. The model material can therefore be considered as round elastic grains with negligible friction between their surfaces. Although breaking of the bonds can occur, fracturing energy is not considered. Stick-slip behavior is observed in a numerical experiment involving 2D blocks with rough surfaces being rubbed past one another at a constant rate. Slip is initiated when two interlocking asperities push past one another exciting a slip pulse. The pulse fronts propagate with speeds ranging from the Rayleigh wave speed up to a value between the shear and compressional wave speeds in agreement with field observations and theoretical analyses of mode-II rupture. Slip rates are comparable to seismic rates in the initial part of one slip pulse whose front propagates at the Rayleigh wave speed. However, the slip rate is an order of magnitude higher in the main part of pulses, possibly because of the simplified model description that neglected intrinsic friction and the high rates at which the blocks were driven, or alternatively, uncertainty in slip rates obtained through the inversion of seismograms. Particle trajectories during slip have motions normal to the fault, indicating that the fault surfaces jump apart during the passage of the slip pulse. Normal motion is expected as the asperities on the two surfaces ride over one another. The form of the particle trajectories is similar to those observed in stick-slip experiments involving foam rubber blocks ( Brune

  10. Detection of slip from multiple sites in an artificial finger (United States)

    Muridan, N.; Chappell, P. H.; Cotton, D. P. J.; Cranny, A.; White, N. M.


    A Piezoelectric thick-film sensor is a good candidate for the extraction of information from object slip in hand prosthesis. Five slip sensors were fabricated on different linkages of an artificial hand. The signals from each sensor were compared to the output from the sensor mounted on the fingertip. An analysis of the output signals from all the sensors indicates that the linkage sensors also produce similar output signals to the fingertip sensor. In the next phase of the research, velocity and acceleration of the slipped object will be considered in the analysis.

  11. Pengurangan Hambatan Aliran pada Celah Silinder Koaksial Akibat Slip


    Yanuar; Gunawan; M. Baqi


    Slip effect which occurs at the wall due to the layer of water repellent wall can reduce the pressure drop. The highly water repellent wall coating on the inside coaxial viscometer slip will be occur. The aim of experiment is proving drag reducing of the torque on the cylinder and the coefficient of velocity slip due to the water repellent coating on the wall. Teflon and wax materials are used to coat the surface of the wall. Contact angle of water droplets with a Teflon-coated walls and waxe...

  12. Simulation of engine auxiliary drive V-belt slip motion. Part 1. Development of belt slip model; Engine hoki V belt slip kyodo no simulation. 1. Belt slip model no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Kurisu, T. [Mazda Motor Corp., Hiroshima (Japan)


    V-belts are widely used for driving auxiliary components of an engine. Inadequet design of such belt system sometimes results in troubles such as belt squeak, side rubber separation and/or bottom rubber crack. However, there has been no design tools which can predict belt slip quantitatively. The author developed a motion simulation program of Auxiliary Drive V-Belt System considering belt slip. The program showed good prediction accuracy for belt slip motion. This paper describes the simulation model. 1 ref., 12 figs.

  13. Laboratory study of electromagnetic initiation of slip

    Directory of Open Access Journals (Sweden)

    V. Chikhladze


    Full Text Available Recently Russian seismologists reported the triggering effect of MHD soundings on microseismic activity in the Central Asia test area.The paper focuses on an experimental test of the possibility of triggering the mechanical instability of a system that is close to critical state by a series of electromagnetic pulses.The mechanical system consisted of two pieces of rock;the upper piece can slip on the fixed supporting sample if the latter one is tilted up to the critical angle.In this state,the triggering of mechanical instability by some weak impact such as electrical pulse became more probable.The slope of support in the experiment is an analogue of tectonic stress in natural conditions.The preliminary experiments,carried out in a dry environment,at the humidity of atmosphere 30-50%,show that a strong EM-pulse induces sliding of a sample of rock (granite,basalt,labradoriteplaced on the supporting sample which is inclined at the slope close to,but less than,the critical angle with a probability 0.07.

  14. Vertically bounded double diffusive convection in the fingering regime: comparing no-slip vs free-slip boundary conditions

    CERN Document Server

    Yang, Yantao; Lohse, Detlef


    Vertically bounded fingering double diffusive convection (DDC) is numerically investigated, focusing on the influences of different velocity boundary conditions, i.e. the no-slip condition which is inevitable in the lab-scale experimental research, and the free-slip condition which is an approximation for the interfaces in many natural environments, such as the oceans. For both boundary conditions the flow is dominated by fingers and the global responses follow the same scaling laws, with enhanced prefactors for the free-slip cases. Therefore, the laboratory experiments with the no-slip boundaries serve as a good model for the finger layers in the ocean. Moreover, in the free-slip case although the tangential shear stress is eliminated at the boundaries, the local dissipation rate in the near-wall region may exceed the value found in the no-slip cases, which is caused by the stronger vertical motions of fingers and sheet structures near the free-slip boundaries. This counter intuitive result might be relevant...

  15. Slip distribution, strain accumulation and aseismic slip on the Chaman Fault system (United States)

    Amelug, F.


    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 MBalochistan and the populated areas such as the city of Quetta.

  16. Performances Evaluation of a Novel Hadoop and Spark Based System of Image Retrieval for Huge Collections

    Directory of Open Access Journals (Sweden)

    Luca Costantini


    Full Text Available A novel system of image retrieval, based on Hadoop and Spark, is presented. Managing and extracting information from Big Data is a challenging and fundamental task. For these reasons, the system is scalable and it is designed to be able to manage small collections of images as well as huge collections of images. Hadoop and Spark are based on the MapReduce framework, but they have different characteristics. The proposed system is designed to take advantage of these two technologies. The performances of the proposed system are evaluated and analysed in terms of computational cost in order to understand in which context it could be successfully used. The experimental results show that the proposed system is efficient for both small and huge collections.

  17. A New Pixels Flipping Method for Huge Watermarking Capacity of the Invoice Font Image

    Directory of Open Access Journals (Sweden)

    Li Li


    Full Text Available Invoice printing just has two-color printing, so invoice font image can be seen as binary image. To embed watermarks into invoice image, the pixels need to be flipped. The more huge the watermark is, the more the pixels need to be flipped. We proposed a new pixels flipping method in invoice image for huge watermarking capacity. The pixels flipping method includes one novel interpolation method for binary image, one flippable pixels evaluation mechanism, and one denoising method based on gravity center and chaos degree. The proposed interpolation method ensures that the invoice image keeps features well after scaling. The flippable pixels evaluation mechanism ensures that the pixels keep better connectivity and smoothness and the pattern has highest structural similarity after flipping. The proposed denoising method makes invoice font image smoother and fiter for human vision. Experiments show that the proposed flipping method not only keeps the invoice font structure well but also improves watermarking capacity.

  18. Huge mucinous cystadenoma of ovary, describing a young patient: case report

    Directory of Open Access Journals (Sweden)

    Soheila Aminimoghaddam


    Conclusion: Ovarian cysts in young women who are associated with elevated levels of tumor markers and ascites require careful evaluation. Management of ovarian cysts depends on patient's age, size of the cyst, and its histopathological nature. Conservative surgery such as ovarian cystectomy or salpingo-oophorectomy is adequate in mucinous tumors of ovary. Multiple frozen sections are very important to know the malignant variation of this tumor and helps accurate patient management. Surgical expertise is required to prevent complications in huge tumors has distorted the anatomy, so gynecologic oncologist plays a prominent role in management. In this case, beside of the huge tumor and massive ascites uterine and ovaries were preserved by gynecologist oncologist and patient is well up to now.

  19. Huge gastric diospyrobezoars successfully treated by oral intake and endoscopic injection of Coca-Cola. (United States)

    Chung, Y W; Han, D S; Park, Y K; Son, B K; Paik, C H; Jeon, Y C; Sohn, J H


    A diospyrobezoar is a type of phytobezoar that is considered to be harder than any other types of phytobezoars. Here, we describe a new treatment modality, which effectively and easily disrupted huge gastric diospyrobezoars. A 41-year-old man with a history of diabetes mellitus was admitted with lower abdominal pain and vomiting. Upper gastrointestinal endoscopy revealed three huge, round diospyrobezoars in the stomach. He was made to drink two cans of Coca-Cola every 6 h. At endoscopy the next day, the bezoars were partially dissolved and turned to be softened. We performed direct endoscopic injection of Coca-Cola into each bezoar. At repeated endoscopy the next day, the bezoars were completely dissolved.

  20. Successful Vaginal Delivery despite a Huge Ovarian Mucinous Cystadenoma Complicating Pregnancy: A Case Report

    Directory of Open Access Journals (Sweden)

    Dipak Mandi


    Full Text Available A 22-year-old patient with 9 months of amenorrhea and a huge abdominal swelling was admitted to our institution with an ultrasonography report of a multiloculated cystic space-occupying lesion, almost taking up the whole abdomen (probably of ovarian origin, along with a single live intrauterine fetus. She delivered vaginally a boy baby within 4 hours of admission without any maternal complication, but the baby had features of intrauterine growth restriction along with low birth weight. On the 8th postpartum day, the multiloculated cystic mass, which arose from the right ovary and weighed about 11 kg, was removed via laparotomy. A mucinous cystadenoma with no malignant cells in peritoneal washing was detected in histopathology examination. This report describes a rare case of a successful vaginal delivery despite a huge cystadenoma of the right ovary complicating the pregnancy.

  1. Huge Neck Masses Causing Respiratory Distress in Neonates: Two Cases of Congenital Cervical Teratoma. (United States)

    Gezer, Hasan Özkan; Oğuzkurt, Pelin; Temiz, Abdulkerim; Bolat, Filiz Aka; Hiçsönmez, Akgün


    Congenital cervical teratomas are rare and usually large enough to cause respiratory distress in the neonatal period. We present two cases of congenital huge cystic neck masses in which distinguishing cervical cystic hygroma and congenital cystic teratoma was not possible through radiologic imaging techniques. Experience with the first case, which was initially diagnosed and treated as cystic hygroma by injection sclerotherapy, led to early suspicion and surgery in the second case. The masses were excised completely and histopathologic diagnoses were congenital teratoma in both patients. Our aim is to review congenital huge neck masses causing respiratory distress in early neonatal life to highlight this dilemma briefly with these interesting cases. Copyright © 2014. Published by Elsevier B.V.

  2. Huge echinococcal cyst of the liver managed by hepatectomy: Report of two cases. (United States)

    Pavlidis, Efstathios T; Symeonidis, Nikolaos; Psarras, Kyriakos; Pavlidis, Theodoros E


    Echinococcocal cysts are predominantly located in the right liver. They are usually solitary and asymptomatic, but large cysts can cause compression symptoms. We report two cases of huge (25cm and 20cm in diameter, respectively) echinococcal cysts located in the left liver, which presented as a large palpable mass causing compression symptoms. Diagnosis was established with CT scan showing a cystic mass with the characteristic daughter cysts and reactive layer (pericystic wall) consisting of fibrous connective tissue and calcifications. Both patients were treated radically with left hepatectomy and had uneventful postoperative course and no recurrence upon follow-up. The treatment of liver echinococcal cysts represent a unique surgical challenge. Even though conservative approaches are less technically demanding, the radical approach with resection has better outcome with less recurrences, when performed by experienced surgeons. Resection rather than drainage is the management of choice for such huge liver echinococcal cysts. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  3. The huge Package for High-dimensional Undirected Graph Estimation in R (United States)

    Zhao, Tuo; Liu, Han; Roeder, Kathryn; Lafferty, John; Wasserman, Larry


    We describe an R package named huge which provides easy-to-use functions for estimating high dimensional undirected graphs from data. This package implements recent results in the literature, including Friedman et al. (2007), Liu et al. (2009, 2012) and Liu et al. (2010). Compared with the existing graph estimation package glasso, the huge package provides extra features: (1) instead of using Fortan, it is written in C, which makes the code more portable and easier to modify; (2) besides fitting Gaussian graphical models, it also provides functions for fitting high dimensional semiparametric Gaussian copula models; (3) more functions like data-dependent model selection, data generation and graph visualization; (4) a minor convergence problem of the graphical lasso algorithm is corrected; (5) the package allows the user to apply both lossless and lossy screening rules to scale up large-scale problems, making a tradeoff between computational and statistical efficiency. PMID:26834510

  4. Mitral valve regurgitation due to annular dilatation caused by a huge and floating left atrial myxoma. (United States)

    Kaya, Mehmet; Ersoy, Burak; Yeniterzi, Mehmet


    We describe a case of mitral valve annular dilatation caused by a huge left atrial myxoma obstructing the mitral valve orifice. A 50-year-old man presenting with palpitation was found to have a huge left atrial myxoma protruding into the left ventricle during diastole, causing severe mitral regurgitation. The diagnosis was made with echocardiogram. Transoesophageal echocardiography revealed a solid mass of 75 × 55 mm. During operation, the myxoma was completely removed from its attachment in the atrium. We preferred to place a mechanical heart valve after an annuloplasty ring because of severely dilated mitral annulus and chordae elongation. The patient had an uneventful recovery. Our case suggests that immediate surgery, careful evaluation of mitral valve annulus preoperatively is recommended.

  5. [Resection of a Huge Gastrointestinal Stromal Tumor of the Stomach Following Neoadjuvant Chemotherapy with Imatinib]. (United States)

    Sato, Yoshihiro; Karasawa, Hideaki; Aoki, Takeshi; Imoto, Hirofumi; Tanaka, Naoki; Watanabe, Kazuhiro; Abe, Tomoya; Nagao, Munenori; Ohnuma, Shinobu; Musha, Hiroaki; Takahashi, Masanobu; Motoi, Fuyuhiko; Naitoh, Takeshi; Ishioka, Chikashi; Unno, Michiaki


    We report a case of a huge gastric gastrointestinal stromal tumor(GIST)that was safely resected followingpreoperative imatinib therapy. A 72-year-old woman was hospitalized with severe abdominal distension. Computed tomography revealed a 27×17 cm tumor in the left upper abdominal cavity. The patient was diagnosed with high risk GIST by EUS-FNA. We initiated preoperative adjuvant chemotherapy with imatinib to achieve a reduction of operative risks and functional preservation. After 6 months of chemotherapy, CT showed a reduction in the tumor size and the patient underwent partial gastrectomy and partial resection of the diaphragm. Histologically, most of the tumor cells were replaced by hyalinized collagen and viable cells were scattered only around the blood vessels. Neoadjuvant chemotherapy with imatinib has the potential to become an important therapeutic option for the treatment of huge GISTs.

  6. Huge mass in right side of the heart: A rare case report. (United States)

    Ghasemi, Reza; Ghanei-Motlagh, Fahimeh; Nazari, Susan; Yaghubi, Mohsen


    The presence of primary intracardiac tumors are scarce, and most of them are myxomas. We reported, in this paper, a case with huge mass in the right side of the heart. A 45-year-old man, with a complaint of bilateral lower limbs edema and exertional dyspnea, was admitted to intensive cardiac care unit. Cardiac auscultation revealed soft grade systolic murmur without any evidence of "tumor plop." Echocardiography showed a huge mobile mass in right side of the heart that suggested myxoma. Our patient underwent cardiac surgery with excision of 13 cm mass. Histopathological study was confirmed the diagnosis of mass type. In this case report, it shows that in the differential diagnosis of right-sided heart failure, the right sided myxoma must be considered. The preferable approach in patient with cardiac myxomas is surgical excision to alleviate symptoms, early identification, and removal.

  7. Huge Dissected Ascending Aorta Associated with Pseudo Aneurysm and Aortic Coarctation Feridoun

    Directory of Open Access Journals (Sweden)

    Feridoun Sabzi


    Full Text Available We report a unique case of chronic dissection of the ascending aorta complicated with huge and thrombotic pseudoaneurysm in a patient with coarctation of descending aorta. Preoperative investigations such as transesophageal echocardiography (TEE confirmed the diagnosis of dissection. Intraoperative findings included a12 cm eccentric bulge of the right lateral side of dilated the ascending aorta filled with the clot and a circular shaped intimal tear communicating with an extended hematoma and dissection of the media layer. The rarity of the report is an association of the chronic dissection with huge pseudoaneurysm and coarctation. The patient underwent staged repair of an aneurysm and coarctation and had an uneventful postoperative recovery period.

  8. A new pixels flipping method for huge watermarking capacity of the invoice font image. (United States)

    Li, Li; Hou, Qingzheng; Lu, Jianfeng; Xu, Qishuai; Dai, Junping; Mao, Xiaoyang; Chang, Chin-Chen


    Invoice printing just has two-color printing, so invoice font image can be seen as binary image. To embed watermarks into invoice image, the pixels need to be flipped. The more huge the watermark is, the more the pixels need to be flipped. We proposed a new pixels flipping method in invoice image for huge watermarking capacity. The pixels flipping method includes one novel interpolation method for binary image, one flippable pixels evaluation mechanism, and one denoising method based on gravity center and chaos degree. The proposed interpolation method ensures that the invoice image keeps features well after scaling. The flippable pixels evaluation mechanism ensures that the pixels keep better connectivity and smoothness and the pattern has highest structural similarity after flipping. The proposed denoising method makes invoice font image smoother and fiter for human vision. Experiments show that the proposed flipping method not only keeps the invoice font structure well but also improves watermarking capacity.

  9. Air conditioning management of huge rooms; Gestion climatique des locaux de grande dimension

    Energy Technology Data Exchange (ETDEWEB)

    Guitton, P. [Electricite de France (EDF), 78 - Chatou (France); Izard, J.L. [Ecole d`Architecture de Marseille-Luminy, 13 - Marseille-Luminy (France); Wurtz, E. [La Rochelle Universite, 17 - La Rochelle, LEPTAB (France)] [and others


    This conference was organized by the section `air-conditioning engineering` of the French society of thermal engineers (SFT). This document comprises the abridged versions of the communications and deals with: air-conditioning using displacement: experience feedback on tertiary applications and development of a dimensioning tool, thermal response of linear atria, application of the zonal method to the description of the temperature field and flows pattern inside an auditorium, theoretical and experimental study of air renewal inside industrial rooms, management of huge rooms, design of new optimized buildings and use of the TAS software, can TRNSYS and Comis codes be used for huge spaces?, experimental study of the thermal-aeraulic conditions generated by a displacement air-conditioning device. (J.S.)

  10. Stochastic Huge-Resonance Caused by Coupling for a Globally Coupled Linear System

    Institute of Scientific and Technical Information of China (English)

    LI Jing-Hui


    In the paper, we investigate a globally coupled linear system with finite subunits subject to temporal periodic force and with multiplicative dichotomous noise.It is shown that, the global coupling among the subunits can hugely enhance the phenomenon of SR for the amplitude of the average mean field as the functions of the transition rate of the noise and that as the function of the frequency of the signal respectively.

  11. Therapeutic benefit of radiotherapy in huge (≥10 cm) unresectable hepatocellular carcinoma. (United States)

    Kim, Kyung Hwan; Kim, Mi Sun; Chang, Jee Suk; Han, Kwang-Hyub; Kim, Do Young; Seong, Jinsil


    Huge (≥10 cm) hepatocellular carcinomas (HCCs) show dismal prognosis and only a limited number of cases are eligible for curative resection. We studied the therapeutic benefit of radiotherapy (RT) in patients with huge unresectable HCCs. Data from 283 patients with huge HCCs and preserved liver function who underwent non-surgical treatment from July 2001 to March 2012 were retrospectively reviewed. Patients were divided into 4 groups according to the initial treatment: Group A (N= 49), transarterial chemoembolization (TACE); Group B (N = 35), TACE + RT; Group C (N = 50), hepatic arterial infusion chemotherapy; and Group D (n = 149), concurrent chemoradiotherapy (CCRT). The median follow-up period was 27.8 months (range, 12.9-121.9 months). The median overall survival (OS) was longer in Groups B (15.3 months) and D (12.8 months) than in Groups A (7.5 months) and C (8.2 months; Group B vs. A, Bonferroni corrected P [P(c)] = 0.04; Group B vs. C, P(c) = 0.02; Group D vs. A, P(c) = 0.01; Group D vs. C, Pc = 0.006). Groups B and D also showed superior progression-free survival (PFS) and intrahepatic control than Groups A and C. In multivariate analysis, tumour multiplicity, serum alpha-foetoprotein level (≥200 ng/ml) and initial treatment were independent prognostic factors for OS and PFS. Patients with huge unresectable HCCs treated with RT, either as CCRT or in combination with TACE, showed excellent intrahepatic control and prolonged survival. RT could be considered a promising treatment modality in these patients. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Interaction-induced huge magnetoresistance in a high mobility two-dimensional electron gas

    Energy Technology Data Exchange (ETDEWEB)

    Bockhorn, L.; Haug, R. J. [Institut für Festkörperphysik, Leibniz Universität Hannover, D-30167 Hannover (Germany); Gornyi, I. V. [Institut für Nanotechnologie, Karlsruher Institut of Technology, D-76021 Karlsruhe (Germany); Schuh, D. [Institut für Experimentelle und Angewandte Physik, Universität Regensburg, D-93053 Regensburg (Germany); Wegscheider, W. [ETH Zürich (Switzerland)


    A strong negative magnetoresistance is observed in a high-mobility two-dimensional electron gas in a GaAs/Al{sub 0.3}Ga{sub 0.7}As quantum well. We discuss that the negative magnetoresistance consists of a small peak induced by a combination of two types of disorder and a huge magnetoresistance explained by the interaction correction to the conductivity for mixed disorder.


    Directory of Open Access Journals (Sweden)



    Full Text Available Hydatid disease of the brain is a rare parasitic infestation caused by larval stage of Echinococcus granulosus. It has an insidious onset with a slow rate of growth resulting in late diagnosis. Its occurence is rare in India, being endemic in Mediterranean countries and Middle East. We report a case of a huge, slow - growing, silent intracranial left parieto - temporo - occipital hydatid cyst in an 18 year old male presenting as a large cystic space occupying lesion.

  14. The Slip History and Source Statistics of Major Slow Slip Events along the Cascadia Subduction Zone from 1998 to 2008 (United States)

    Gao, H.; Schmidt, D. A.


    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

  15. Post-renal acute renal failure due to a huge bladder stone. (United States)

    Celik, Orcun; Suelozgen, Tufan; Budak, Salih; Ilbey, Yusuf Ozlem


    A 63-year old male was referred to our emergency unit due to acute renal failure. The level of serum renal function tests levels, blood urea nitrogen (BUN)/creatinine, were 63 mmol/L/848 μmol/L. CT (Computarised Tomography) scan showed a huge bladder stone (5 cm x 6 cm x 5 cm) with increased bladder wall thickness. Post-renal acute renal failure due to bilateral ureterohydronephrosis was diagnosed. The huge bladder stone was considered to be the cause of ureterohydronephrosis and renal failure. The patient was catheterised and received haemodialysis immediately. He received haemodialysis four times during ten days of hospitalization and the level of serum renal function tests levels (BUN/ creatinine) decreased 18 mmol/L/123 μmol/L. After improvement of renal function, we performed cystoscopy that demonstrated normal prostatic urethra and bladder neck and bilaterally normal ureteral orifices. Bladder wall was roughly trabeculated and Bladder outlet was completely obstructed by a huge bladder stone. After cystoscopy open, cystolithotomy was performed to remove calcium phosphate and magnesium ammonium phosphate stone weighing 200 g removed. Four days after operation the patient was discharged uneventfully and urethral catheter was removed on the seventh day. Post-renal acute renal failure due to large bladder stones is rare in literature. According to the our knowledge; early diagnosis of the stone avoid growth to large size and prevent renal failure.

  16. Safety and efficacy of partial hepatectomy for huge (≥10 cm) hepatocellular carcinoma: A systematic review (United States)

    Zhou, Yan-Ming; Li, Bin; Xu, Dong-Hui; Yang, Jia-Mei


    Summary Huge (≥10 cm) hepatocellular carcinoma (HCC) is not uncommon at clinical presentation, and the surgical outcomes of such tumors are poor. This systematic review aimed to assess the safety and efficacy of partial hepatectomy for huge HCC. We performed a search on Medline and PubMed databases for all relevant studies published prior to December 2009. After exclusions, 21 studies remained for appraisal and data extraction. All studies were classified as level-4 evidence. The median overall perioperative morbidity and mortality rates were 29.2% (range: 13.6–72%) and 3.5% (range: 0–18.2%), respectively. The overall median survival since the partial hepatectomy was 20.7 months (range: 10.1–32 months), with median 1-, 3- and 5-year survival of 60.7% (range: 41–72.2%), 34% (range: 0–60.3%) and 28.6% (range: 0–54%), respectively. The median disease-free survival since the partial hepatectomy was 11.3 months (range: 5.5–32months), with median 1-, 3- and 5-year disease-free survival rates of 48.7% (range: 32–65.4%), 27.5% (range: 14.1–49%) and 20.7% (range: 9.5–43%), respectively. Partial hepatectomy can be performed safely and is associated with long-term survival in a subset of patients with huge HCC, but the evidence of benefit is currently weak. PMID:21358616

  17. Huge focal nodular hyperplasia presenting in a 6-year-old child: A case presentation. (United States)

    Zhuang, Lin; Ni, Chuangye; Din, Wenbing; Zhang, Feng; Zhuang, Yi; Sun, Yawei; Xi, Dong


    Focal nodular hyperplasia (FNH) is a benign lesion of the liver which is usually found in healthy adults, however, FNH is rare in children, and comprises only 2% of all pediatric liver tumors. Herein, we report the case of a 6-year-old child (male) with a huge FNH which size is more than 10cm. This could be the biggest FNH among all children's FNH cases ever reported. A 6-year-old boy was found a hepatic space-occupying lesion two years ago. As the time went by, the lesion became bigger gradually. The last CT examination showed the size of the tumor to be 10.5×9.9cm in the right hepatic lobe. This child underwent surgical resection of the tumor which was confirmed as FNH (11×8×7cm) by pathology. FNH is a benign lesion of the liver, and it is characterized by hepatocyte hyperplasia and a central stellate scar. It is uncommon for FNH to be diagnosed in children. Such huge FNH (about 11cm) is extremely rare. Surgical operation may be the effective method to cure huge FNH. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. Modified concentric craniotomy for the removal of a huge calvarial metastatic tumor: technical note. (United States)

    Kao, Ying; Yang, Shih-Hung; Kuo, Meng-Fai


    It is challenging for neurosurgeons to remove huge tumors involving the skull that may possibly invade the dura or intracranial neural tissue. In this situation, excision of the tumor may cause profound blood loss, unexpected opening of the dura, or neurological injury. We describe a technique of craniotomy in a pediatric patient to avoid surgical complications. A 15-year-old boy had a huge metastatic calvarial Ewing's sarcoma. We removed the tumor successfully with modified concentric craniotomy. First, two oval burr holes are made on both sides of the tumor. The inner craniotomy uses the internal margin of the oval holes, while the outer cut uses the outer margins. The skull bone in between the two craniotomies is removed easily in two pieces and the dura surrounding the tumor can be exposed early in the procedure. In this way, the huge skull tumor can be removed en bloc under direct vision to avoid unwanted complications. Minimal blood and bone loss can be achieved. Blood transfusion was not necessary during the surgery. The patient did not have new neurological symptoms and signs after surgery. The goal of the modified concentric craniotomy is to develop an accessible margin of the dura surrounding the bulky tumor in the early phase of surgery. Blood and bone loss can be reduced significantly.

  19. Intraoperative fluorescent cholangiography using indocyanine green for laparoscopic fenestration of nonparasitic huge liver cysts. (United States)

    Kitajima, Toshihiro; Fujimoto, Yasuhiro; Hatano, Etsuro; Mitsunori, Yusuke; Tomiyama, Koji; Taura, Kojiro; Mizumoto, Masaki; Uemoto, Shinji


    Bile duct injury is one of the known serious complications of laparoscopic fenestration for nonparasitic liver cysts. Herein, we report the case of a huge liver cyst for which we performed laparoscopic fenestration using intraoperative fluorescent cholangiography with indocyanine green. A 71-year-old woman with abdominal distention was referred to our hospital. CT demonstrated a 17 × 11.5-cm simple cyst replacing the right lobe of the liver, so laparoscopic fenestration was performed. Although the biliary duct could not be detected because of compression by the huge cyst, fluorescent cholangiography with indocyanine green through endoscopic naso-biliary drainage tube clearly delineated the intrahepatic bile duct in the remaining cystic wall. The patient had no complications at 3 months after surgery. Fluorescent cholangiography using indocyanine green is a safe and effective procedure to avoid bile duct injury during laparoscopic fenestration, especially in patients with a huge liver cyst. © 2015 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and Wiley Publishing Asia Pty Ltd.

  20. Efficacy of hepatic resection vs transarterial chemoembolization for solitary huge hepatocellular carcinoma. (United States)

    Zhu, Shao-Liang; Zhong, Jian-Hong; Ke, Yang; Ma, Liang; You, Xue-Mei; Li, Le-Qun


    To compare the efficacy of hepatic resection (HR) and transarterial chemoembolization (TACE) for patients with solitary huge (≥ 10 cm) hepatocellular carcinoma (HCC). Records were retrospectively analyzed of 247 patients with solitary huge HCC, comprising 180 treated by HR and 67 by TACE. Long-term overall survival (OS) was compared between the two groups using the Kaplan-Meier method, and independent predictors of survival were identified by multivariate analysis. These analyses were performed using all patients in both groups and/or 61 pairs of propensity score-matched patients from the two groups. OS at 5 years was significantly higher in the HR group than the TACE group, across all patients (P = 0.002) and across propensity score-matched pairs (36.4% vs 18.2%, P = 0.039). The two groups showed similar postoperative mortality and morbidity. Multivariate analysis identified alpha-fetoprotein ≥ 400 ng/mL, presence of vascular invasion and TACE treatment as independent predictors of poor OS. Our findings suggest that HR can be safe and more effective than TACE for patients with solitary huge HCC.

  1. Huge Intramural Hematoma in a Thrombosed Middle Cerebral Artery Aneurysm: A Case Report. (United States)

    Kim, Hak Jin; Lee, Sang Won; Lee, Tae Hong; Kim, Young Soo


    We describe a case of a huge intramural hematoma in a thrombosed middle cerebral artery aneurysm. A 47-year-old female patient with liver cirrhosis and thrombocytopenia presented to the neurosurgical unit with a 5-day history of headache and cognitive dysfunction. Magnetic resonance imaging and computed tomography of the brain showed a thrombosed aneurysm located in the right middle cerebral artery with a posteriorly located huge intramural hematoma mimicking an intracerebral hematoma. Imaging studies and cerebrospinal fluid analysis showed no evidence of subarachnoid hemorrhage. Angiography showed a partially thrombosed aneurysm at the origin of the right anterior temporal artery and an incidental aneurysm at the bifurcation of the right middle cerebral artery. Both aneurysms were embolized by coiling. After embolization, the thrombosed aneurysmal sac and intramural hematoma had decreased in size 4 days later and almost completely disappeared 8 months later. This is the first reported case of a nondissecting, nonfusiform aneurysm with a huge intramural hematoma, unlike that of a dissecting aneurysm.


    Institute of Scientific and Technical Information of China (English)

    CHAIYan-ju; OUJi-kun; RENChao


    A new method is proposed for detecting and repairing cycle slips in GPS navigation based on the dual frequency observations. It can be implemented through the following three steps: (1) The integer ambiguities of the current epoch are substituted by that of the previous epoch, so the ambiguity parameters are removed from the observation equations. (2) The abnormal observations are detected using the quasi accurate detection (QUAD) method and the satellite pairs of these abnormal observations are determined. Then the coefficient matrix of these satellite pairs is recovered. (3) The cycle slips of these satellite pairs are calculated using the LAMBDA method and integer ambiguities of the current epoch can be determined by adding the cycle slips into the integer ambiguities of the previous epoch. The key of this method is that the abnormal observations must accurately he detected, i.e. , the satellites having cycle slips must correctly be judged. Finally, compared with other methods the feasibility of the method is verified.

  3. Wheel slip dump valve for railway braking system (United States)

    Zhang, Xuan; Zhang, LiHao; Li, QingXuan; Shi, YanTao


    As we all know, pneumatic braking system plays an important role in the safety of the whole vehicle. In the anti slip braking system, the pressure of braking cylinder can be adjusted by the quick power response of wheel slip dump valve, so that the lock situation won’t occur during vehicle service. During the braking of railway vehicles, the braking force provided by braking disc reduces vehicle’s speed. But the locking slip will happen due to the oversize of braking force or the reduction of sticking coefficient between wheel and rail. It will cause not only the decline of braking performance but also the increase of braking distance. In the meanwhile, it will scratch the wheel and influence the stable running of vehicles. Now, the speed of passenger vehicle has been increased. In order to shorten the braking distance as far as possible, sticking stickiness must be fully applied. So the occurrence probability of wheel slip is increased.

  4. Accurate speed and slip measurement of induction motors

    Energy Technology Data Exchange (ETDEWEB)

    Ho, S.Y.S.; Langman, R. [Tasmania Univ., Hobart, TAS (Australia)


    Two alternative hardware circuits, for the accurate measurement of low slip in cage induction motors, are discussed. Both circuits compare the periods of the fundamental of the supply frequency and pulses from a shaft-connected toothed-wheel. The better of the two achieves accuracy to 0.5 percent of slip over the range 0.1 to 0.005, or better than 0.001 percent of speed over the range. This method is considered useful for slip measurement of motors supplied by either constant frequency mains of variable speed controllers with PMW waveforms. It is demonstrated that accurate slip measurement supports the conclusions of work previously done on the detection of broken rotor bars. (author). 1 tab., 6 figs., 13 refs.

  5. Some sources for a slip in a translation by Freud. (United States)

    Grossman, W I


    Among Freud's papers, we find instances in which Freud describes the "psychopathology of everyday life" as he found it in himself and in others. "A Religious Experience" (Freud, 1928) contains examples of both kinds. In addition, this paper contains a slip of which Freud appears to have been unaware. Freud's paper interprets a religious conversion described in a letter written to him in English. In the translation of this letter into German, Freud inserted material that was not present in the original. He mentions another slip he made in speaking about the letter. These slips and some associated details in the paper indicate persisting unconscious conflict. The content of these slips and details points to an association with Freud's childhood anxiety dream reported in The Interpretation of Dreams (Freud, 1900). Freud's associations and discussion of that dream lead to the Philippson Bible of his childhood, which provides additional connections to the paper of 1928.

  6. Analytical approximations for stick-slip vibration amplitudes

    DEFF Research Database (Denmark)

    Thomsen, Jon Juel; Fidlin, A.


    The classical "mass-on-moving-belt" model for describing friction-induced vibrations is considered, with a friction law describing friction forces that first decreases and then increases smoothly with relative interface speed. Approximate analytical expressions are derived for the conditions......, the amplitudes, and the base frequencies of friction-induced stick¿slip and pure-slip oscillations. For stick¿slip oscillations, this is accomplished by using perturbation analysis for the finite time interval of the stick phase, which is linked to the subsequent slip phase through conditions of continuity...... and periodicity. The results are illustrated and tested by time-series, phase plots and amplitude response diagrams, which compare very favorably with results obtained by numerical simulation of the equation of motion, as long as the difference in static and kinetic friction is not too large....

  7. Slip Updip of Tremor during the 2012 Cascadia ETS Event (United States)

    Hall, K.; Houston, H.


    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. Wheel rolling constraints and slip in mobile robots

    Energy Technology Data Exchange (ETDEWEB)

    Shekhar, S. [Oak Ridge National Lab., TN (United States). Robotics and Process Systems Div.


    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.

  9. Slipping Rib Syndrome as Persistent Abdominal and Chest Pain. (United States)

    Bolaños-Vergaray, Juan Javier; de la Gala García, Francisco; Obaya Rebollar, Juan Carlos; Bové Alvarez, Maria


    Slipping rib syndrome is an overlooked cause of persistent abdominal or chest pain. The etiology of this syndrome is not well understood, but the characteristic pain is from hypermobility of the false ribs. Although it is a diagnosis of exclusion, misdiagnosis may lead to an excessive workup. A simple clinical examination via the hooking maneuver is the most significant feature of its diagnosis. We describe the case of a 41-year-old woman with slipping rib syndrome.

  10. The Crawford Slip Method: An Organizational Development Technique (United States)


    This thesis is dedicated to the memory of Professor John Demidovich , whose interest and research inspired this study. - Debra Trent ii i ,I...According to Demidovich and Crawford (undated), the Crawford Slip Method is a system aimed at handling a large amount of inputs from a large number of...Ross Clayton, in an article by Crawford and Demidovich (1983a), states that few management techniques have the potential of the Crawford Slip Method as

  11. A non-slip boundary condition for lattice Boltzmann simulations

    CERN Document Server

    Inamuro, T; Ogino, F; Inamuro, Takaji; Yoshino, Masato; Ogino, Fumimaru


    A non-slip boundary condition at a wall for the lattice Boltzmann method is presented. In the present method unknown distribution functions at the wall are assumed to be an equilibrium distribution function with a counter slip velocity which is determined so that fluid velocity at the wall is equal to the wall velocity. Poiseuille flow and Couette flow are calculated with the nine-velocity model to demonstrate the accuracy of the present boundary condition.

  12. Foreshocks during the nucleation of stick-slip instability (United States)

    McLaskey, Gregory C.; Kilgore, Brian D.


    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.

  13. Slip Magnetohydrodynamic Viscous Flow over a Permeable Shrinking Sheet

    Institute of Scientific and Technical Information of China (English)

    FANG Tie-Gang; ZHANG Ji; YAO Shan-shan


    @@ The magnetohydrodynamic(MHD)flow under slip conditions over a shrinMng sheet js solved analytically.The solution is given in a closed form equation and is an exact solution of the full governing Navier-Stokes equations.Interesting solution behavior is observed with muiriple solution branches for certain parameter domain.The effects of the mass transfer,slip,andmagnetic parameters are discussed.

  14. Wheel rolling constraints and slip in mobile robots

    Energy Technology Data Exchange (ETDEWEB)

    Shekhar, S.


    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.

  15. Wheel rolling constraints and slip in mobile robots

    Energy Technology Data Exchange (ETDEWEB)

    Shekhar, S.


    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. The author establishes 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.

  16. Disaster Characteristics and Mitigation Measures of Huge Glacial Debris Flows along the Sichuan-Tibet Railway (United States)

    Liu, Jinfeng; You, Yong; Zhang, Guangze; Wang, Dong; Chen, Jiangang; Chen, Huayong


    The Ranwu-Tongmai section of the Sichuan-Tibet Railway passes through the Palongzangbu River basin which locates in the southeast Qinghai-Tibetan Plateau. Due to widely distributed maritime glacier in this area, the huge glacier debris flows are very developed. Consequently, the disastrous glacier debris flows with huge scale (106-108 m3 for one debris flow event) and damage become one of the key influencing factors for the route alignment of the Sichuan-Tibet Railway. The research on disaster characteristics and mitigation measures of huge glacial debris flows in the study area were conducted by the remote sensing interpretation, field investigation, parameter calculation and numerical simulation. Firstly, the distribution of the glaciers, glacier lakes and glacier debris flows were identified and classified; and the disaster characteristics for the huge glacier debris flow were analyzed and summarized. Secondly, the dynamic parameters including the flood peak discharge, debris flow peak discharge, velocity, total volume of a single debris flow event were calculated. Based on the disaster characteristics and the spatial relation with the railway, some mitigation principles and measures were proposed. Finally, the Guxiang Gully, where a huge glacier debris flow with 2*108m3 in volume occurred in 1953, was selected as a typical case to analyze its disaster characteristics and mitigation measures. The interpretation results show that the glacier area is about 970 km2 which accounts for 19% of the total study area. 130 glacier lakes and 102 glacier debris flows were identified and classified. The Sichuan-Tibet Railway passes through 43 glacier debris flows in the study area. The specific disaster characteristics were analyzed and corresponding mitigation measures were proposed for the route selection of the railway. For the Guxiang Gully, a numerical simulation to simulate the deposition condition at the alluvial fan was conducted. the simulation results show that the

  17. Molecular Dynamics Simulations of Slip on Curved Surfaces

    Directory of Open Access Journals (Sweden)

    Ross D.A.


    Full Text Available We present Molecular Dynamics (MD simulations of liquid water confined within nanoscale geometries, including slit-like and cylindrical graphitic pores. These equilibrium results are used for calculating friction coefficients, which in turn can be used to calculate slip lengths. The slip length is a material property independent of the fluid flow rate. It is therefore a better quantity for study than the fluid velocity at the wall, also known as the slip velocity. Once the slip length has been found as a function of surface curvature, it can be used to parameterise Lattice Boltzmann (LB simulations. These larger scale simulations are able to tell us about how fluid transport is affected by slip in complex geometries; not just limited to single pores. Applications include flow and transport in nano-porous engine valve deposits and gas shales. The friction coefficient is found to be a function of curvature and is higher for fluid on convex surfaces and lower for concave surfaces. Both concave and convex surfaces approach the same value of the friction coefficient, which is constant above some critical radius of curvature, here found to be 7.4 ± 2.9 nm. The constant value of the friction coefficient is 10,000 ± 600 kg m−2 s−1, which is equivalent to a slip length of approximately 67 ± 4 nm.

  18. Small sized slip-ring capsule endurance testing (United States)

    Mondier, Jean-Bernard


    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.

  19. Numerical Treatments of Slipping/No-Slip Zones in Cold Rolling of Thin Sheets with Heavy Roll Deformation

    Directory of Open Access Journals (Sweden)

    Yukio Shigaki


    Full Text Available In the thin sheet cold rolling manufacturing process, a major issue is roll elastic deformation and its impact on roll load, torque and contact stresses. As in many systems implying mechanical contact under high loading, a central part is under “sticking friction” (no slip while both extremities do slip to accommodate the material acceleration of the rolled metal sheet. This is a crucial point for modeling of such rolling processes and the numerical treatment of contact and friction (“regularized” or not, of the transition between these zones, does have an impact on the results. Two ways to deal with it are compared (regularization of the stick/slip transition, direct imposition of a no-slip condition and recommendations are given.

  20. A Multicoefficient Slip-Corrected Reynolds Equation for Micro-Thin Film Gas Lubrication

    Directory of Open Access Journals (Sweden)

    Ng Eddie Yin-Kwee


    Full Text Available This work investigates and analyzes the performance of conventional slip models among various regimes of Knudsen number and developes a new multicoefficient slip-velocity model, by using Taguchi quality control techniques and numerical analysis. A modified Reynolds equation is also derived based on the new slip-flow model. The multicoefficient slip model and its slip-corrected Reynolds equation are suitable to a wide Knudsen range from slip to transition regime. In comparison with other conventional slip models, it is found that the current results have a better agreement with the solution obtained from the linearized Boltzmann equation and direct simulation of Monte Carlo method (DSMC.

  1. Severe progressive scoliosis due to huge subcutaneous cavernous hemangioma: A case report

    Directory of Open Access Journals (Sweden)

    Toyama Yoshiaki


    Full Text Available Abstract Cavernous hemangioma consists mainly of congenital vascular malformations present before birth and gradually increasing in size with skeletal growth. A small number of patients with cavernous hemangioma develop scoliosis, and surgical treatment for the scoliosis in such cases has not been reported to date. Here we report a 12-year-old male patient with severe progressive scoliosis due to a huge subcutaneous cavernous hemangioma, who underwent posterior correction and fusion surgery. Upon referral to our department, radiographs revealed a scoliosis of 85° at T6-L1 and a kyphosis of 58° at T4-T10. CT and MR images revealed a huge hemangioma extending from the subcutaneous region to the paraspinal muscles and the retroperitoneal space and invading the spinal canal. Posterior correction and fusion surgery using pedicle screws between T2 and L3 were performed. Massive hemorrhage from the hemangioma occurred during the surgery, with intraoperative blood loss reaching 2800 ml. The scoliosis was corrected to 59°, and the kyphosis to 45° after surgery. Seven hours after surgery, the patient suffered from hypovolemic shock and disseminated intravascular coagulation due to postoperative hemorrhage from the hemangioma. The patient developed sensory and conduction aphasia caused by cerebral hypoxia during the shock on the day of the surgery. At present, two years after the surgery, although the patient has completely recovered from the aphasia. This case illustrates that, in correction surgery for scoliosis due to huge subcutaneous cavernous hemangioma, intraoperative and postoperative intensive care for hemodynamics should be performed, since massive hemorrhage can occur during the postoperative period as well as the intraoperative period.

  2. High platelet counts increase metastatic risk in huge hepatocellular carcinoma undergoing transarterial chemoembolization. (United States)

    Xue, Tong-Chun; Ge, Ning-Ling; Xu, Xin; Le, Fan; Zhang, Bo-Heng; Wang, Yan-Hong


    Accumulating evidence suggests platelets play critical roles in tumor metastasis. Moreover, the role of platelets in metastasis is partially correlated with inflammation. However, evidence regarding the contribution of platelets to hepatocellular carcinoma (HCC) metastasis is lacking. This study investigated the association between platelets and metastatic risk in HCC. We used huge HCC (diameter over 10 cm), a tumor subgroup with a strong inflammatory background, as a model to evaluate the potential predictive role of platelets and platelet-related biomarkers for metastasis in HCC patients undergoing transarterial chemoembolization. A logistic regression model was used to analyze risk factors for metastasis. Patients with huge HCC (n = 178) were enrolled, and 24.7% (44/178) of patients had remote metastases after treatment. Univariate analyses showed high platelet counts (P = 0.012), pretreatment platelet-to-lymphocyte ratios (pre-PLR) of 100 or more (P = 0.018) and post-PLR of 100 or more (P = 0.013) were potential risk factors for metastasis. Furthermore, multivariate analyses showed high platelet counts (odds ratio, 2.18; 95% confidence interval, 1.074-4.443; P = 0.031) and platelet-related biomarkers were independent risk factors for HCC metastasis. Particularly, the risk of metastasis in patients with high post-PLR values was significantly greater than patients with low post-PLR values. For tumor response and survival, patients with high platelet counts had faster disease progression (P = 0.002) and worse survival (P huge HCC undergoing chemoembolization, which supply clinical verification of the association between high platelet counts and HCC metastasis. © 2016 The Japan Society of Hepatology.

  3. The efficacy of stereotactic body radiation therapy on huge hepatocellular carcinoma unsuitable for other local modalities. (United States)

    Que, Jenny Y; Lin, Li-Ching; Lin, Kuei-Li; Lin, Chia-Hui; Lin, Yu-Wei; Yang, Ching-Chieh


    To evaluate the safety and efficacy of Cyberknife stereotactic body radiation therapy (SBRT) and its effect on survival in patients with unresectable huge hepatocellular carcinoma (HCC) unsuitable of other standard treatment option. Between 2009 and 2011, 22 patients with unresectable huge HCC (≧10 cm) were treated with SBRT. dose ranged from 26 Gy to 40 Gy in five fractions. Overall survival (OS) and disease-progression free survival (DPFS) were determined by Kaplan-Meier analysis. Tumor response and toxicities were also assessed. After a median follow-up of 11.5 month (range 2-46 months). The objective response rate was achieved in 86.3% (complete response (CR): 22.7% and partial response (PR): 63.6%). The 1-yr. local control rate was 55.56%. The 1-year OS was 50% and median survival was 11 months (range 2-46 months). In univariate analysis, Child-Pugh stage (p = 0.0056) and SBRT dose (p = 0.0017) were significant factors for survival. However, in multivariate analysis, SBRT dose (p = 0.0072) was the most significant factor, while Child-Pugh stage of borderline significance. (p = 0.0514). Acute toxicities were mild and well tolerated. This study showed that SBRT can be delivered safely to huge HCC and achieved a substantial tumor regression and survival. The results suggest this technique should be considered a salvage treatment. However, local and regional recurrence remain the major cause of failure. Further studies of combination of SBRT and other treatment modalities may be reasonable.

  4. Slipping of the foot on the floor when pulling a pallet truck. (United States)

    Li, Kai Way; Chang, Chien-Chi; Chang, Wen-Ruey


    Workers pulling pallet trucks are likely to slip when pulling and stepping on a low-friction floor. This study investigated the slipping 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 slip either upon landing of the leading foot on the toe (slip I) or before taking off of the lagging foot on the heel (slip II). The results indicated that the slip distances for both types of slip were significantly affected by the load and surface conditions and their interactions. Micro-slips (slips between 0.1 and 3 cm) and midi-slips (slips between 3 and 10 cm) were more common in slip I than in slip II. On glycerol-contaminated surfaces, the probabilities of a slide, or a slip more than 10 cm, for both slips I and II were over 40%. The implications of the results were discussed.

  5. Hot, Fast Faults: Evidence for High-Temperature Slip on Exhumed Faults, and Insights into Seismic Slip Processes (United States)

    Evans, J. P.; Ault, A. K.; Janecke, S. U.; Prante, M. R.


    Microstructural and geochemical techniques combined with prior observations of naturally occurring faults provide insights into slip rates and slip 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 slip. Thin, high-gloss, Fe-rich slip surfaces indicate high-temperature slip 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 slip surfaces to record instantaneous slip. 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-slip 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 slip

  6. The big, large and huge case of state-building

    DEFF Research Database (Denmark)

    Harste, Gorm

      Using communication theory as point of departure, it is not evident how to study macro phenomena. Michel Foucault limited his studies to a non-Grand Theory when studying discursive events. At the same time, Charles Tilly wrote about Big Structures, Large Processes, Huge Comparisons when trying...... to establish a perspective on a macro phenomena as European state formation. With Luhmann's system theory, the claim is that there is no such contradiction between Grand evolution and particular semantic history. Passing through some classic studies of the historical establishment of interaction systems...

  7. The  Big, Large and Huge Case of State-Building

    DEFF Research Database (Denmark)

    Harste, Gorm


      Using communication theory as point of departure it is not evident how to study macro phenomena. Michel Foucault delimited his studies to a non-Grand Theory when he studied discursive events. At the same time Charles Tilly wrote about Big Structures, Large Processes, Huge Comparisons when he...... tried to establish a perspective on a macro phenomena as European state formation. With Luhmann's system theory, the claim is that there is no such contradiction between Grand evolution and particular semantic history. Passing through some classic studies of the historical establishment of interaction...

  8. Huge malignant phyllodes breast tumor: a real entity in a new era of early breast cancer. (United States)

    Testori, Alberto; Meroni, Stefano; Errico, Valentina; Travaglini, Roberto; Voulaz, Emanuele; Alloisio, Marco


    Phyllodes tumor is an extremely rare tumor of the breast. It occurs in females in the third and fourth decades. The difficulty in distinguishing between phyllodes tumors and benign fibroadenoma may lead to misdiagnosis. Lymph node involvement is rarely described in phyllodes tumors; for this reason, sentinel node biopsy may be warranted. We present a case of a 33-year-old woman affected by huge tumor of the right breast with ulceration in the skin with a rapid tumor growth and with omolateral axillary metastasis.

  9. Huge Benign Ovarian Cystic Teratoma in a Patient with a History of Hansen's Disease. (United States)

    Okonta, Patrick I; Mofon, Chukwuemeke


    Mature ovarian cystic teratomas are common benign ovarian neoplasm derived from germ cells. With increasing availability of ultrasound services even in developing countries, the diagnosis of benign ovarian tumour is made earlier and the size of the ovarian tumour at diagnosis is relatively small. It is unusual to find an ovarian cystic teratoma larger than 10 cm. We report a huge mature ovarian cystic teratoma in a multipara with a history of Hansen's disease. We conclude that, in circumstances where women have restricted access to health care, the unusual finding of mature ovarian cystic teratoma larger than 10 cm is possible due to delayed presentation for diagnosis and treatment.

  10. Creating and Exploring Huge Parameter Spaces: Interactive Evolution as a Tool for Sound Generation

    DEFF Research Database (Denmark)

    Dahlstedt, Palle


    of huge synthesis parameter spaces, and presents a possibility for the sound artist to create new sound engines customized for this kind of creation and exploration – sound engines too complex to control in any other way. Different sound engines are presented, together with a discussion of compositional......In this paper, a program is presented that applies interactive evolution to sound generation, i.e., preferred individuals are repeatedly selected from a population of genetically bred sound objects, created with various synthesis and pattern generation algorithms. This simplifies aural exploration...

  11. Huge capacity fiber-optic sensing network based on ultra-weak draw tower gratings (United States)

    Yang, Minghong; Bai, Wei; Guo, Huiyong; Wen, Hongqiao; Yu, Haihu; Jiang, Desheng


    This paper reviews the work on huge capacity fiber-optic sensing network based on ultra-weak draw tower gratings developed at the National Engineering Laboratory for Fiber Optic Sensing Technology (NEL-FOST), Wuhan University of Technology, China. A versatile drawing tower grating sensor network based on ultra-weak fiber Bragg gratings (FBGs) is firstly proposed and demonstrated. The sensing network is interrogated with time- and wavelength-division multiplexing method, which is very promising for the large-scale sensing network.

  12. En bloc resection of huge cemento-ossifying fibroma of mandible: avoiding lower lip split incision. (United States)

    Ayub, Tahera; Katpar, Shahjahan; Shafique, Salman; Mirza, Talat


    Cemento-ossifying Fibroma (COF) is an osteogenic benign neoplasm affecting the jaws and other craniofacial bones. It commonly presents as a progressively slow growing pathology, which can sometimes attain an enormous size, causing facial deformity. A case of a huge cemento-ossifying fibroma, appearing as a mandibular dumbell tumour in a male patient is documented, which caused massive bone destruction and deformity. It was surgically removed by performing en bloc resection of mandible avoiding the splitting of lower lip incision technique, thereby maintaining his normal facial appearance.

  13. Huge Intrathoracic Malignant Peripheral Nerve Sheath Tumor in an Adolescent with Neurofibromatosis Type 1

    Directory of Open Access Journals (Sweden)

    Jong Hyung Yoon


    Full Text Available Malignant peripheral nerve sheath tumor (MPNST is a rare soft tissue malignancy usually found in patients with neurofibromatosis type 1 (NF1 with a poor outcome. Although MPNST can be found in any part of the body including head and neck or extremities, intrathoracic MPNST with or without NF1 is uncommon, especially in children or adolescents. Reported herein is a case of huge intrathoracic MPNST in a 16-year-old girl with NF1, and a brief review of the literature.

  14. Huge gastric bezoar caused by honeycomb, an unusual complication of health faddism: a case report (United States)

    Katsinelos, Panagiotis; Pilpilidis, Ioannis; Katsinelos, Taxiarchis; Lazaraki, Georgia; Fasoulas, Kostas; Zavos, Christos; Kountouras, Jannis


    We report a young healthy woman, who believed that the consumption of large amounts of honeycomb would lead to good health and who finally developed a huge gastric bezoar of hard consistency. The conventional endoscopic techniques failed to manage the bezoar. Using the combination of injection of hydrogen peroxide 3% solution inside the bezoar to induce disintegration and a special designed needle-knife sphincterotome (bezotome) we managed to remove the bezoar in fragments. To the best of our knowledge this is the first reported bezoar caused by honeycomb. PMID:19829904

  15. A huge chondromyxoid fibroma of the nasal cavity in a newborn baby. (United States)

    Yoo, Young Tae; Park, Joo Hyun; Sunwoo, Woong Sang; Rhee, Chae-Seo


    Chondromyxoid fibroma is a rare benign tumor that usually occurs in the long bones. A 2-month newborn presented with huge masses in the both nasal cavities, which turned out to be chondromyxoid fibroma. The masses originated from both inferior turbinates. Total turbinectomy on the left side and submucosal mass excision on the right side were performed. No recurrence or new lesion was observed during the 2 years of follow up. We report here on a rare case of nasal cavity chondromyxoid fibroma in a neonate and we review the relevant literature.

  16. Totally laparoscopic gastrectomy for early gastric cancer accompanied by huge hiatal hernia: A case report. (United States)

    Hagiwara, Chie; Yajima, Kazuhito; Iwasaki, Yoshiaki; Oohinata, Ryouki; Yuu, Ken; Ishiyama, Satoshi; Amaki, Misato; Nakano, Daisuke; Yamaguchi, Tatsuro; Matsumoto, Hiroshi; Takahashi, Keiichi


    We herein present a case in which we used a totally laparoscopic approach for early gastric cancer accompanied by a huge hiatal hernia. An 80-year-old Japanese woman was referred with a chief complaint of dysphagia. A clinical diagnosis of early gastric cancer, T1b (SM) N0M0, stage IA, accompanied by hiatal hernia, was made. Distal gastrectomy with D1 plus lymphadenectomy was carried out. After the gastrectomy, the hernial sac was excised and the hernial orifice was closed. Reconstruction using the Roux-en-Y method was selected. The postoperative course was uneventful and she was discharged on postoperative day 10.

  17. Huge aneurysm and coronary-cameral fistula from right coronary branch: First case. (United States)

    Ahmad, Tanveer; Pasarad, Ashwini Kumar; Kishore, Kolkebaile Sadanand; Maheshwarappa, Nandakumar Neralakere


    Coronary-cameral fistulas are rare cardiovascular anomalies. A giant coronary artery aneurysm associated with a coronary-cameral fistula is a very rare condition, with an estimated prevalence of 0.02%. We report the case of middle-aged woman who presented with a huge extracardiac aneurysmal mass and a coronary-cameral fistula from a right coronary artery branch. It was successfully repaired by ligation and excision plus marsupialization of the aneurysm. We believe this is the first such a case reported in literature.

  18. Design of a superluminal ring laser gyroscope using multilayer optical coatings with huge group delay. (United States)

    Qu, Tianliang; Yang, Kaiyong; Han, Xiang; Wu, Suyong; Huang, Yun; Luo, Hui


    We propose and analyze a superluminal ring laser gyroscope (RLG) using multilayer optical coatings with huge group delay (GD). This GD assisted superluminal RLG can measure the absolute rotation with a giant sensitivity-enhancement factor of ~10(3); while, the broadband FWHM of the enhancement factor can reach 20 MHz. This superluminal RLG is based on a traditional RLG with minimal re-engineering, and beneficial for miniaturization according to theoretical calculation. The idea of using GD coatings as a fast-light medium will shed lights on the design and application of fast-light sensors.

  19. Nonoperative treatment of slipped capital femoral epiphysis: a scientific study

    Directory of Open Access Journals (Sweden)

    Pinheiro Pedro


    Full Text Available Abstract Background Treatment of the Slipped Capital Femoral Epiphysis remains a cause of concern due to the fact that the true knowledge of the etiopathogeny is unknown, as well as one of its major complications: chondrolysis. The conservative treatment remains controversial; it has been overlooked in the studies and subjected to intense criticism. The purpose of this study is to investigate the results of treatment on the hip of patients displaying slipped capital femoral epiphysis, using the plaster cast immobilization method and its link to chondrolysis. Methods The research was performed based on the study of the following variables: symptomatology, and the degree of slipping. A hip spica cast and bilateral short/long leg casts in abduction, internal rotation with anti-rotational bars were used for immobilizing the patient's hip for twelve weeks. Statistical analysis was accomplished by Wilcoxon's marked position test and by the Fisher accuracy test at a 5% level. Results A satisfactory result was obtained in the acute group, 70.5%; 94%; in the chronic group (chronic + acute on chronic. Regarding the degree of the slipping, a satisfactory result was obtained in 90.5% of hips tested with a mild slip; in 76% with moderate slip and 73% in the severe slip. The statistical result revealed that a significant improvement was found for flexion (p = 0.0001, abduction (p = 0.0001, internal rotation (p = 0.0001 and external rotation (p = 0.02. Chondrolysis was present in 11.3% of the hips tested. One case of pseudoarthrosis with aseptic capital necrosis was presented. There was no significant variation between age and chondrolysis (p = 1.00.Significant variation between gender/non-white patients versus chondrolysis (p = 0.031 and (p = 0.037, respectively was verified. No causal association between plaster cast and chondrolysis was observed (p = 0.60. In regard to the symptomatology group and the slip degree versus chondrolysis, the p value was not

  20. Long-term survival after surgical resection for huge hepatocellular carcinoma: comparison with transarterial chemoembolization after propensity score matching. (United States)

    Min, Yang Won; Lee, Jun Hee; Gwak, Geum-Youn; Paik, Yong Han; Lee, Joon Hyoek; Rhee, Poong-Lyul; Koh, Kwang Cheol; Paik, Seung Woon; Yoo, Byung Chul; Choi, Moon Seok


    Surgical resection (SR) and transarterial chemoembolization (TACE) have been commonly applied for patients with huge hepatocellular carcinoma (HCC). However, optimal treatment has not been established. Between 2000 and 2009, 267 patients with huge HCC (≥ 10 cm) underwent TACE and 84 underwent SR as the first treatment. Propensity score matching generated a matched cohort composed of 152 patients. We investigated overall survival and possible prognostic factors. At baseline, the surgery group showed a tendency to have solitary tumor (72.6% vs 39.3%, P huge HCC. © 2013 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

  1. Scaling analysis for the investigation of slip mechanisms in nanofluids

    Directory of Open Access Journals (Sweden)

    Savithiri S


    Full Text Available Abstract The primary objective of this study is to investigate the effect of slip mechanisms in nanofluids through scaling analysis. The role of nanoparticle slip 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 slip mechanisms are dominant in particles of cylindrical shape as compared to that of spherical and sheet particles. The magnitudes of slip 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 slip 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.

  2. Measurement of Quantum Phase-Slips in Josephson Junction Chains (United States)

    Guichard, Wiebke


    Quantum phase-slip 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-slips on the ground state of a Josephson junction chain. We can tune in situ the strength of the phase-slips. These phase-slips 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-slip 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.

  3. Scaling analysis for the investigation of slip mechanisms in nanofluids (United States)

    Savithiri, S.; Pattamatta, Arvind; Das, Sarit K.


    The primary objective of this study is to investigate the effect of slip mechanisms in nanofluids through scaling analysis. The role of nanoparticle slip 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 slip mechanisms are dominant in particles of cylindrical shape as compared to that of spherical and sheet particles. The magnitudes of slip 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 slip 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.

  4. How Orogen-scale Exhumed Strike-slip Faults Initiate (United States)

    Cao, S.; Neubauer, F.


    Orogen-scale strike-slip 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-slip faults implying major transtensive and/or transpressive processes accompanying pure strike-slip 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-slip initiates and further development. Here, we propose a model in which major continental exhumed strike-slip 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.

  5. A huge 6.2 kilogram uterine myoma coinciding with omental leiomyosarcoma: case report. (United States)

    Ruan, C W; Lee, C L; Yen, C F; Wang, C J; Soong, Y K


    Surgery for massive abdominal tumors is both interesting and challenging. We present a case involving a multiple uterine myoma weighing 6.2 Kg which coincided with omental leiomyosarcoma. To our knowledge, this is the first report of this type of condition in the English literature. A 44-year-old nulliparous woman had suffered from abdominal pain for a long time. A huge abdominal mass was palpated on physical examination. Computed tomography scanning revealed a huge pelvic-abdominal mass with the possibility of small bowel loops invaded by the mass. A 6-cm omental mass was incidentally found during the subsequent hysterectomy procedure. Perforation of the urinary bladder occurred during the dissection of adhesion. Resection of the omental mass, wide wedge resection of the invaded small bowel, primary repair of the bladder, and hysterectomy were performed. The final pathologic diagnosis was uterine leiomyomata with omental leiomyosarcoma. The patient returned home on postoperative day 14 and was well at the 18-month follow-up examination. The challenge of these tumors lies in their proper diagnosis and surgical management. More case reports and follow-up studies are needed to confirm the efficacy of their management.

  6. Treatment of Huge Hepatocellular Carcinoma Using Cinobufacini Injection in Transarterial Chemoembolization: A Retrospective Study

    Directory of Open Access Journals (Sweden)

    Jun Dong


    Full Text Available The aim of this study is to examine the safety and efficacy of Cinobufacini injection in transarterial chemoembolization (TACE for treatment of huge hepatocellular carcinoma (HCC. Clinical data of 56 consecutive patients with HCC larger than 10 cm who had been treated with TACE between December 2010 and August 2014 were retrospectively analyzed. Among these patients, 31 belonged to the Cinobufacini group and 25 belonged to the epirubicin group. The clinical efficacy, survival time, and adverse events in patients in the two groups were compared. The objective response rate in the Cinobufacini group was significantly higher than that in the epirubicin group (53.6% versus 23.1%, P=0.022. The median survival time (10.6 versus 14.1 months, χ2=0.092, P=0.762 and the median time to progression (4.9 versus 5.7 months, χ2=0.097, P=0.756 were similar between the groups. The incidence rate of adverse events was lower in the Cinobufacini group than in the epirubicin group (P<0.05. The short-term clinical efficacy of Cinobufacini is better than that of epirubicin in TACE for treating huge HCC, while their long-term clinical efficacy is similar. However, lower incidence of adverse events was noted in TACE using Cinobufacini rather than epirubicin.

  7. Surgical resection of a huge cemento-ossifying fibroma in skull base by intraoral approach. (United States)

    Cheng, Xiao-Bing; Li, Yun-Peng; Lei, De-Lin; Li, Xiao-Dong; Tian, Lei


    Cemento-ossifying fibroma, also known as ossifying fibroma, usually occurs in the mandible and less commonly in the maxilla. The huge example in the skull base is even rare. We present a case of a huge cemento-ossifying fibroma arising below the skull base of a 30-year-old woman patient. Radiologic investigations showed a giant, lobulated, heterogeneous calcified hard tissue mass, which is well circumscribed and is a mixture of radiolucent and radiopaque, situated at the rear of the right maxilla to the middle skull base. The tumor expands into the right maxillary sinus and the orbital cavity, fusing with the right maxilla at the maxillary tuberosity and blocking the bilateral choanas, which caused marked proptosis and blurred vision. The tumor was resected successfully by intraoral approach, and pathologic examination confirmed the lesion to be a cemento-ossifying fibroma. This case demonstrates that cemento-ossifying fibroma in the maxilla, not like in the mandible, may appear more aggressive because the extensive growth is unimpeded by anatomic obstacles and that the intraoral approach can be used to excise the tumor in the skull base.

  8. The technical research on the huge glazed brick from the relic of Nanyue Kingdom Palace

    Institute of Scientific and Technical Information of China (English)


    'Qin brick and Han tile' has a great worldwide reputation in the architectural history of China. According to the former archaeological materials, the big hollow brick is usually one meter long and thirty to forty centimeters wide, while the solid brick is generally much smaller. But in 1995, large scale vestiges and structures were unearthed at the center of Guangzhou's old district, from the relic of Nanyue Kingdom Palace, which was built some 2000 years ago during the Western-Han Dynasty, A great number of earthen structural members were discovered, especially the solid glazed bricks in various beautiful patterns with an astonishing thickness and size. Some of them are one meter square, more than 20 centimeters thick, and weight half a ton, which are named ‘Brick No.1 in the world' by excavators. People have shown great interest in how to make these huge glazed bricks at the ancient technical conditions, because it is very difficult to manufacture such huge bricks even with the modern technology. At the request of Guangdong Nanyue Kingdom Palace Museum, Shanghai Institute of Ceramics carried out systematical measurements and analysis on these bricks and studied the physical and chemical forming mechanisms from their chemical compositions, structure, and physical characteristics. Here the technical characteristics of the bricks are also discussed.

  9. The technical research on the huge glazed brick from the relic of Nanyue Kingdom Palace

    Institute of Scientific and Technical Information of China (English)


    ‘Qin brick and Han tile’ has a great worldwide reputation in the architectural history of China. According to the former archaeological materials, the big hollow brick is usually one meter long and thirty to forty centimeters wide, while the solid brick is generally much smaller. But in 1995, large scale vestiges and structures were un- earthed at the center of Guangzhou’s old district, from the relic of Nanyue Kingdom Palace, which was built some 2000 years ago during the Western-Han Dynasty. A great number of earthen structural members were discovered, especially the solid glazed bricks in various beautiful patterns with an astonishing thickness and size. Some of them are one meter square, more than 20 centimeters thick, and weight half a ton, which are named ‘Brick No.1 in the world’ by excavators. People have shown great interest in how to make these huge glazed bricks at the ancient tech- nical conditions, because it is very difficult to manufacture such huge bricks even with the modern technology. At the request of Guangdong Nanyue Kingdom Palace Museum, Shanghai Institute of Ceramics carried out systematical measurements and analysis on these bricks and studied the physical and chemical forming mechanisms from their chemical compositions, structure, and physical character- istics. Here the technical characteristics of the bricks are also discussed.

  10. Treatment of Huge Hepatocellular Carcinoma Using Cinobufacini Injection in Transarterial Chemoembolization: A Retrospective Study. (United States)

    Dong, Jun; Zhai, Xiaofeng; Chen, Zhe; Liu, Qun; Ye, Hua; Chen, Wei; Ling, Changquan


    The aim of this study is to examine the safety and efficacy of Cinobufacini injection in transarterial chemoembolization (TACE) for treatment of huge hepatocellular carcinoma (HCC). Clinical data of 56 consecutive patients with HCC larger than 10 cm who had been treated with TACE between December 2010 and August 2014 were retrospectively analyzed. Among these patients, 31 belonged to the Cinobufacini group and 25 belonged to the epirubicin group. The clinical efficacy, survival time, and adverse events in patients in the two groups were compared. The objective response rate in the Cinobufacini group was significantly higher than that in the epirubicin group (53.6% versus 23.1%, P = 0.022). The median survival time (10.6 versus 14.1 months, χ (2) = 0.092, P = 0.762) and the median time to progression (4.9 versus 5.7 months, χ (2) = 0.097, P = 0.756) were similar between the groups. The incidence rate of adverse events was lower in the Cinobufacini group than in the epirubicin group (P huge HCC, while their long-term clinical efficacy is similar. However, lower incidence of adverse events was noted in TACE using Cinobufacini rather than epirubicin.

  11. Addressing huge spatial heterogeneity induced by virus infections in lentil breeding trials. (United States)

    Kargiotidou, Anastasia; Vlachostergios, Dimitrios N; Tzantarmas, Constantinos; Mylonas, Ioannis; Foti, Chrysanthi; Menexes, George; Polidoros, Alexios; Tokatlidis, Ioannis S


    Spatial heterogeneity can have serious effects on the precision of field experimentation in plant breeding. In the present study the capacity of the honeycomb design (HD) to sample huge spatial heterogeneity was appraised. For this purpose, four trials were conducted each comprising a lentil landrace being screened for response to viruses. Huge spatial heterogeneity was reflected by the abnormally high values for coefficient of variation (CV) of single-plant yields, ranging 123-162 %. At a given field area, increasing the number of simulated entries was followed by declined effectiveness of the method, on account of the larger circular block implying greater intra-block heterogeneity; a hyperbolic increasing pattern of the top to bottom entry mean gap (TBG) indicated that a number of more than 100 replicates (number of plants per entry) is the crucial threshold to avoid significant deterioration of the sampling degree. Nevertheless, the honeycomb model kept dealing with variation better than the randomized complete block (RCB) pattern, thanks to the circular shape and standardized type of block that ensure the less possible extra heterogeneity with expanding the area of the block. Owing to the even and systematic entry allocation, breeders do not need to be concerned with the extra spatial heterogeneity that might induce the extra surface needed to expand the size of the block when many entries are considered. Instead, they could improve accuracy of comparisons with increasing the number of replicates (circular blocks) despite the concomitant greater overall spatial heterogeneity.

  12. Challenging the time complexity of exact subgraph isomorphism for huge and dense graphs with VF3. (United States)

    Carletti, Vincenzo; Foggia, Pasquale; Saggese, Alessia; Vento, Mario


    Graph matching is essential in several fields that use structured information, such as biology, chemistry, social networks, knowledge management, document analysis and others. Except for special classes of graphs, graph matching has in the worst-case an exponential complexity; however, there are algorithms that show an acceptable execution time, as long as the graphs are not too large and not too dense. In this paper we introduce a novel subgraph isomorphism algorithm, VF3, particularly efficient in the challenging case of graphs with thousands of nodes and a high edge density. Its performance, both in terms of time and memory, has been assessed on a large dataset of 12700 random graphs with a size up to 10000 nodes, made publicly available. VF3 has been compared with four other state-of-the-art algorithms, and the huge experimentation required more than two years of processing time. The results confirm that VF3 definitely outperforms the other algorithms when the graphs become huge and dense, but also has a very good performance on smaller or sparser graphs.

  13. Strontium-89 therapy for the treatment of huge osseous metastases in prostate carcinoma: A case report. (United States)

    Zhang, Wenjie; Zhao, Weiwei; Jia, Zhiyun; Deng, Houfu


    Prostate cancer is a growing public health problem. The palliation of pain in patients with painful bone metastases is of primary importance in the clinical management of advanced cancer. Internal therapy with radionuclides, which concentrate at sites of increased bone turnover, is used to control pain and improve quality of life as an alternative to conventional therapies. In the present study, we report the case of a 52-year-old male who had been diagnosed with prostate cancer. The patient presented with severe pain in multiple areas, but particularly in the right hip. A whole-body bone scan revealed that the right hip, ilium and ischium were covered with huge metastatic lesions. Treatment with radionuclide strontium-89 chloride ((89)Sr) resulted in a partial response which was confirmed by the successful relief of pain and other imaging modalities. No significant change in the leukocyte or thrombocyte levels was observed. The results of the present study indicate that systemic radionuclide therapy using (89)Sr is an effective, well-tolerated and safe palliative treatment in patients with huge osseous metastases in prostate carcinoma.

  14. Resection of Huge Liver Cancer Involving the Second Porta Hepatis:A Report of 55 Cases

    Institute of Scientific and Technical Information of China (English)

    CHENHan; WUMengchao; WANGYi; WEIGongtian; HULei


    Objective To investigate the possibility and surgical procedures for huge liver cancer involving the second porta hepatis.Methods 55 cases of huge liver cancer, with the diameter of 8-28 cm(mean 12.7 cm) were studied. Right subcostal or “rooftop” incision was made, the liver ligments were divided, good exposure of the tumor and access to retrohepatic inferior vena cava were achieved.Hepatectomies were completed under intermittent interruption of first porta hepatis. Occluding tape around vena cava was applied before liver resection if necessary.Results All tumors were successfully resected without death during operation.The longest survival time was now 4 years in one case. The 1-4 year postoperative survival rates were 63%,50%,50% and 30% respectively.Conclusion Young patients with solitary large liver tumor, which grows slowly over a long period on basis of non-cirrhotic or mild cirrhotic liver, should undergo an exploration in an attempt of resection irrespective of the image contraindication, provided that there is no extra-hepatic metastasis.

  15. [One case of huge cyst at the back end of nasal septum]. (United States)

    Zang, Jian; Liu, Qian; Jiang, Xuejun


    A male of 17 years old complained of bilateral nasal congestion with mouth breathing for half a year. The physical examination showed patency of bilateral nasal cavity. Nasopharyngeal fiberscope revealed a huge spherical smooth reddish mass at the nasopharyngeal posterior wall and the back-end of nasal cavity blocking the entire postnaris and contacting with bilateral tubal tori, the size of which is about 3.5 cm x 2.5 cm. The nasopharyngeal 3D-CT showed a low density cystic mass area in the nasopharynx with smooth edges, and the CT value is approximately 32.4 HU. No exact enhancement was observed. The cystic mass originated from and compressed the back end of nasal septum. A semicircular defect in the leading edge of clivus was observed, and the inferior wall of sphenoid sinus is compressed uplifted upwards. The nasopharyngeal MR showed that the nasopharyngeal lesion presented short T1 and long T2 signals with multiple small wall nodules around. Neither the lesion nor the peripheral nodules can be significantly enhanced by enhancement scan. After a nasal endoscopic surgery, the case was definitely diagnosed as nasal septum back-end huge cyst.

  16. What causes an icy fault to slip? Investigating strike-slip failure conditions on Ganymede at Dardanus and Tiamat Sulcus. (United States)

    Cameron, M. E.; Smith-Konter, B. R.; Burkhard, L. M.; Collins, G. C.; Seifert, F.; Pappalardo, R. T.


    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-slip faulting and distributed shear zones suggest that strike-slip 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-slip 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 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-slip 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 slip windows for the latter. Moreover, our models predict a right-lateral sense of slip, 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 strike-slip morphologies (en echelon

  17. Atomistic Determination of Cross-Slip Pathway and Energetics

    DEFF Research Database (Denmark)

    Rasmussen, Torben; Jacobsen, Karsten Wedel; Leffers, Torben


    The mechanism for cross slip of a screw dislocation in Cu is determined by atomistic simulations that only presume the initial and final states of the process. The dissociated dislocation constricts in the primary plane and redissociates into the cross-slip plane while still partly in the primary...... plane. The transition state and activation energy for cross slip as well as the energies of the involved dislocation constrictions are determined. One constriction has a negative energy compared to parallel partials. The energy vs splitting width for recombination of parallel partials into a perfect...... dislocation is determined. The breakdown of linear elasticity theory for small splitting widths is studied. [S0031-9007(97)04444-X]....


    Directory of Open Access Journals (Sweden)

    Mohammad Outokesh


    Full Text Available In the present work, slip velocity has been measured in a 76 mm diameter pulsed disc and doughnut extraction column for four different liquid-liquid systems. The effects of operating variables including pulsation intensity and dispersed and continuous phase flow rates on slip velocity have been investigated. The existence of three different operational regimes, namely mixersettler, transition, and emulsion regimes, was observed when the energy input was changed. Empirical correlations are derived for prediction of the slip velocity in terms of operating variables, physical properties of the liquid systems, and column geometry for different regimes. Good agreement between prediction and experiments was found for all operating conditions that were investigated.

  19. Shock slip-relations for thermal and chemical nonequilibrium flows (United States)

    Jinrong, Tang


    This paper appears to be the first where the multi-temperature shock slip-relations for the thermal and chemical nonequilibrium flows are derived. The derivation is based on analysis of the influences of thermal nonequilibrium and viscous effects on the mass, momentum and emergy flux balance relations at the shock wave. When the relaxation times for all internal energy modes tend to zero, the multi-tmperature shock slip-relations are converted into single-temperature ones for thermal equilibrium flows. The present results can be applied to flow over vehicles of different geometries with or without angles of attack. In addition, the present single-temperature shock slip-relations are compared with those in the literature, and some defects and limitations in the latter are clarified.

  20. Preliminary soil-slip susceptibility maps, southwestern California (United States)

    Morton, Douglas M.; Alvarez, Rachel M.; Campbell, Russell H.; Digital preparation by Bovard, Kelly R.; Brown, D.T.; Corriea, K.M.; Lesser, J.N.


    This group of maps shows relative susceptibility of hill slopes to the initiation sites of rainfall-triggered soil slip-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-slip/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 slips) 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 slip-debris flows. The susceptibility maps were created through an iterative process from two kinds of information. First, locations of sites of past soil slips were obtained from inventory maps of past events. Aerial photographs, taken during six rainy seasons that produced abundant soil slips, were used as the basis for soil slip-debris flow inventory. Second, digital elevation models (DEM) of the areas that were inventoried were used to analyze the spatial characteristics of soil slip locations. These data were supplemented by observations made on the ground. Certain physical attributes of the locations of the soil-slip 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 slip. However, because the soil slips occur in surficial materials overlying the bedrocks units, the bedrock formation can only serve as

  1. Quantum Nucleation of Phase Slips in 1-d Superfluids (United States)

    Arovas, Daniel


    The rate for quantum nucleation of phase slips 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 slip 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 slip 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

  2. Offset of latest pleistocene shoreface reveals slip rate on the Hosgri strike-slip fault, offshore central California (United States)

    Johnson, Samuel Y.; Hartwell, Stephen R.; Dartnell, Peter


    The Hosgri fault is the southern part of the regional Hosgri–San Gregorio dextral strike‐slip 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 slip rate of 2.6±0.9  mm/yr, considered a minimum rate for the Hosgri given the presence of an active western strand. This slip rate indicates that the Hosgri system takes up the largest share of the strike‐slip fault budget and is the most active strike‐slip 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.

  3. A series of transient slip events on Kilauea volcano, Hawaii. (United States)

    Desmarais, E. K.; Segall, P.; Miklius, A.; Cervelli, P.


    Deformation on Kilauea volcano, Hawaii is monitored by a network of continuously recording GPS stations, among other methds. Since its installation in 1996, the GPS network has detected four spatially coherent accelerations on Kilauea's south flank that are not caused by either intrusions or earthquakes. These events, each lasting several hours to two days, occurred in September 1998, November 2000, July 2003, and January 2005. Previously, Cervelli et al., (Nature, 2002) interpreted the 2000 event as a silent earthquake due to slip on a sub-horizontal fault beneath Kilauea's south flank. We inverted the cumulative displacements ( less than 2 cm) using a simulated annealing algorithm for each event and found similarly sized, near horizontal, uniform slip source locations for all four events at depths of ~6 km. The estimated slip magnitudes are between 9 and 15 cm, with the upper block moving seaward. The 2005 event is the largest detected to date. Volcano-tectonic (VT) earthquakes on the south flank of Kilauea are typically restricted to the volume between the East Rift Zone and the Hilina and Poliokeawe Palis. Seismicity in this volume increased significantly during the silent events at depths of 5-10 km. However, all of the VT earthquakes were small ( less than M3) and their cumulative moment does not account for the moment released during the silent slip events. We are currently examining seismic waveform data for evidence of other signals, such as non-volcanic tremor, that might be associated with the slip events. To determine the exact onset and duration of the silent earthquakes, we invert for slip as a function of time directly from raw GPS phase and pseudorange observations. The November 2000 silent earthquake was preceded 9 days earlier by nearly 1 m of rainfall, which was speculated in Cervelli et al., (Nature, 2002) to have reduced fault stability through surface loading or pore pressure increase. In contrast, both the 2003 and 2005 events occurred

  4. Volcano instability induced by strike-slip faulting (United States)

    Lagmay, A. M. F.; van Wyk de Vries, B.; Kerle, N.; Pyle, D. M.


    Analogue sand cone experiments were conducted to study instability generated on volcanic cones by basal strike-slip movement. The results of the analogue models demonstrate that edifice instability may be generated when strike-slip faults underlying a volcano move as a result of tectonic adjustment. This instability occurs on flanks of the volcano above the strike-slip shear. On the surface of the volcano this appears as a pair of sigmoids composed of one reverse and one normal fault. In the interior of the cone the faults form a flower structure. Two destabilised regions are created on the cone flanks between the traces of the sigmoidal faults. Bulging, intense fracturing and landsliding characterise these unstable flanks. Additional analogue experiments conducted to model magmatic intrusion show that fractures and faults developed within the volcanic cone due to basal strike-slip motions strongly control the path of the intruding magma. Intrusion is diverted towards the areas where previous development of reverse and normal faults have occurred, thus causing further instability. We compare our model results to two examples of volcanoes on strike-slip faults: Iriga volcano (Philippines), which underwent non-magmatic collapse, and Mount St. Helens (USA), where a cryptodome was emplaced prior to failure. In the analogue and natural examples, the direction of collapse takes place roughly parallel to the orientation of the underlying shear. The model presented proposes one mechanism for strike-parallel breaching of volcanoes, recently recognised as a common failure direction of volcanoes found in regions with transcurrent and transtensional deformation. The recognition of the effect of basal shearing on volcano stability enables prediction of the likely direction of eventual flank failure in volcanoes overlying strike-slip faults.

  5. Phase-field slip-line theory of plasticity (United States)

    Freddi, Francesco; Royer-Carfagni, Gianni


    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 slip surfaces, once that a certain energetic barrier for slip 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 slip 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 slip 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 slip-line field theory, but the proposed model is much richer because, accounting for elastic deformations, it can describe the formation of slip 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.

  6. Possible Stick-Slip Mechanism for Whillans Ice Stream (United States)

    Bindschadler, Robert; King, Matt; Vornberger, Patricia


    Tidally-induced stick-slip 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- slip 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-slip 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 slip displacement and present model of the stick-slip process. To match the observed delay between the peak ocean tide and stick-slip 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.

  7. Global strike-slip faults: Bounds from plate tectonics (United States)

    Gordon, R. G.; Argus, D. F.


    According to the tenets of plate tectonics, a transform fault is a strike-slip fault along which neither convergence nor divergence occurs. Analysis of global plate motion data indicates that the only true transform faults are the strike-slip faults that offset segments of mid-ocean ridges. Thus, many of Earth's major strike-slip fault systems are not true transform faults as they accommodate large components of oblique convergence or oblique divergence. This is particularly true for several important ocean-continent systems such as the San Andreas, the strike-slip systems bounding the northern and southern Caribbean plate, the Alpine fault system of New Zealand, the Anatolian fault system, and the Azores-Gibraltar-Alboran sea system. These strike-slip systems are commonly sites of large scale mountain building and basin formation. Here we examine the far-field constraints on the motions of the plates bounding several of these strike-slip systems using both conventional plate motion circuits and results from global positioning system and other space geodetic data. We pay particular attention to the San Andreas fault system in central and northern California, where the San Andreas system is part of the boundary between the Sierran microplate and the Pacific plate. Most of the fault system accommodates obliquely convergent motion, giving rise to the California Coast Range, but in the northern San Francisco Bay Area it is obliquely divergent, producing San Pablo Bay and a gap in the Coast Range that permits the Sierran watershed to drain to the Pacific through the Golden Gate.

  8. Back analysis of fault-slip in burst prone environment (United States)

    Sainoki, Atsushi; Mitri, Hani S.


    In deep underground mines, stress re-distribution induced by mining activities could cause fault-slip. Seismic waves arising from fault-slip 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-slip-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-slip 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-slip 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-slip related seismic events.

  9. Superplastic flow lubricates carbonate faults during earthquake slip (United States)

    De Paola, Nicola; Holdsworth, Robert; Viti, Cecilia; Collettini, Cristiano; Faoro, Igor; Bullock, Rachael


    Tectonic earthquakes are hosted in the shallower portion of crustal fault zones, where fracturing and cataclasis are thought to be the dominant processes during frictional sliding. Aseismic shear in lower crust and lithospheric mantle shear zones is accomplished by crystal plasticity, including superplastic flow acting at low strain rates on ultrafine-grained rocks. Superplasticity has also been observed at high strain rates for a range of nano-phase alloys and ceramics, and could potentially occur in fine-grained geological materials, if deformed at high strain rates and temperatures. We performed a set of displacement-controlled experiments to explore whether superplastic flow can effectively weaken faults, and facilitate earthquake propagation. The experiments were performed on fine-grained synthetic gouges (63 lubrication mechanisms. When T ≥ 800 °C are attained, micro-textures diagnostic of diffusion-dominated grain boundary sliding are widespread within the slip zone, and suggest bulk superplastic flow. Flow stresses predicted by superplasticity constitutive laws at the slip zone temperatures, grain sizes and strain rates attained during the experiments match those we measured in the laboratory (μ = 0.16). We propose therefore that the activation of diffusion creep at high temperatures (T ≥ 800 °C) leads to slip zone-localised superplastic flow and that this causes the dynamic weakening of carbonate faults at seismic slip rates. Note, however, that both cataclasis and dislocation creep operating at lower temperatures, during the earlier stages of slip, are critical, precursory processes needed to produce the nanoscale grain sizes required to activate grainsize sensitive mechanisms during superplastic flow. Finally, the re-strengthening observed during the decelerating phase of deformation can be explained by the falling temperature "switching off" slip zone-localized superplasticity, leading to a return to frictional sliding. These results indicate

  10. The HUGE formula (hematocrit, urea, gender) for screening for chronic kidney disease in elderly patients: a study of diagnostic accuracy. (United States)

    Musso, Carlos G; de Los Rios, Eduardo; Vilas, Manuel; Terrasa, Sergio; Bratti, Griselda; Varela, Federico; Diez, Guillermo Rosa; Jauregui, Jose; Luna, Daniel


    Chronically reduced glomerular filtration rate (GFR) in old people does not always mean that they suffer from chronic kidney disease (CKD) since their GFR can just be reduced by aging. The HUGE equation has been recently described and validated in Spain for screening CKD without taking into account the patient's GFR value. This equation is based on patient's hematocrit, plasma urea levels and gender. The present study documented that the HUGE equation had and acceptable performance for screening CKD in elderly Argentine patients.

  11. 巨大阑尾黏液性囊腺瘤1例%1 case of huge appendiceal mucinous cystadenoma

    Institute of Scientific and Technical Information of China (English)

    王磊; 刘雯雯


    Huge appendiceal mucinous cystadenoma is rare in clinic,and the preoperative misdiagnosis rate is high.The data of 1 case of huge appendiceal mucinous cystadenoma was introduced in this paper.%巨大阑尾黏液性囊腺瘤临床较少见,术前误诊率高。本文对巨大阑尾黏液性囊腺瘤1例的病例资料进行介绍。

  12. A unified slip boundary condition for flow over a surface

    CERN Document Server

    Thalakkottor, Joseph John


    Interface between two phases of matter are ubiquitous in nature and technology. Determining the correct velocity condition at an interface is essential for understanding and designing of flows over a surface. We demonstrate that both the widely used no-slip and the Navier and Maxwell slip boundary conditions do not capture the complete physics associated with complex problems, such as spreading of liquids or corner flows. Hence, we present a unified boundary condition that is applicable to a wide-range of flow problems.

  13. Slip effects on shearing flows in a porous medium

    Institute of Scientific and Technical Information of China (English)

    M.Khan; T.Hayat; Y.Wang


    This paper deals with the magnetohydrodynamic (MHD)flow of an Oldroyd 8-constant fluid in a porous mediam when no-slip condition is no longer valid.Modified Darcy's law is used in the flow modelling.The non-linear differential equation with non-linear boundary conditions is solved numerically using finite difference scheme in combination with an iterative technique.Numerical results are obtained for the Conette,Poiseuille and generalized Couette flows.The effects of slip parameters on the velocity profile are discussed.

  14. Stokes Flow with Slip and Kuwabara Boundary Conditions

    Indian Academy of Sciences (India)

    Sunil Datta; Satya Deo


    The forces experienced by randomly and homogeneously distributed parallel circular cylinder or spheres in uniform viscous flow are investigated with slip boundary condition under Stokes approximation using particle-in-cell model technique and the result compared with the no-slip case. The corresponding problem of streaming flow past spheroidal particles departing but little in shape from a sphere is also investigated. The explicit expression for the stream function is obtained to the first order in the small parameter characterizing the deformation. As a particular case of this we considered an oblate spheroid and evaluate the drag on it.

  15. Effects of Huge Earthquakes on Earth Rotation and the length of Day

    Directory of Open Access Journals (Sweden)

    Changyi Xu


    Full Text Available We calculated the co-seismic Earth rotation changes for several typical great earthquakes since 1960 based on Dahlen¡¦s analytical expression of Earth inertia moment change, the excitation functions of polar motion and, variation in the length of a day (ΔLOD. Then, we derived a mathematical relation between polar motion and earthquake parameters, to prove that the amplitude of polar motion is independent of longitude. Because the analytical expression of Dahlen¡¦s theory is useful to theoretically estimate rotation changes by earthquakes having different seismic parameters, we show results for polar motion and ΔLOD for various types of earthquakes in a comprehensive manner. The modeled results show that the seismic effect on the Earth¡¦s rotation decreases gradually with increased latitude if other parameters are unchanged. The Earth¡¦s rotational change is symmetrical for a 45° dip angle and the maximum changes appear at the equator and poles. Earthquakes at a medium dip angle and low latitudes produce large rotation changes. As an example, we calculate the polar motion and ΔLOD caused by the 2011 Tohoku-Oki Earthquake using two different fault models. Results show that a fine slip fault model is useful to compute co-seismic Earth rotation change. The obtained results indicate Dahlen¡¦s method gives good approximations for computation of co-seismic rotation changes, but there are some differences if one considers detailed fault slip distributions. Finally we analyze and discuss the co-seismic Earth rotation change signal using GRACE data, showing that such a signal is hard to be detected at present, but it might be detected under some conditions. Numerical results of this study will serve as a good indicator to check if satellite observations such as GRACE can detect a seismic rotation change when a great earthquake occur.

  16. The seasonal dependence of cycle slip occurrence of GPS data over China low latitude region

    Institute of Scientific and Technical Information of China (English)

    ZHANG DongHe; FENG Man; XIAO Zuo; HAO YongQiang; SHI LiQin; YANG GuangLin; SUO YuCheng


    The relationship of daily accumulated cycle slip occurrence with the season is analyzed using the GPS data observed in six GPS stations located in China low latitude region in 2001. It is found that the seasonal dependence of cycle slip occurrence is evident. The cycle slip mainly occurs during the periods of two equinox months (March to May and September to October), and some correlative changes of the cycle slip occurrences over all six stations are exhibited in some special days. Considering the diurnal dependence of cycle slip, it can be inferred that the cycle slip occurrence with certain elevation limitation is related with the ionospheric irregularities over this region.

  17. Huge hepatocellular carcinoma greater than 10 cm in diameter worsens prognosis by causing distant recurrence after curative resection. (United States)

    Wakayama, Kenji; Kamiyama, Toshiya; Yokoo, Hideki; Orimo, Tatsuya; Shimada, Shingo; Einama, Takahiro; Kamachi, Hirofumi; Taketomi, Akinobu


    This study aimed to evaluate the impact of huge (≥10 cm) hepatocellular carcinoma (HCC) to the recurrence pattern and the prognosis after hepatectomy. 574 patients who underwent hepatectomy by 17 surgeons (Open 536 and Laparoscopic 38) for HCC without major vascular invasion from 1990 to 2013 at single institute were retrospectively analyzed. Huge tumor, age, HCV, multiple tumors and microscopic portal invasion are independent risk factors for overall survival (OS), and huge tumor, ICGR15 ≥16%, multiple tumors, moderate/poor histology, microscopic portal invasion and a positive pathological margin are risk factors for relapse-free survival (RFS). The 5-year OS and RFS of patients with huge HCC (n = 53) (42.9 and 14.2%) were significantly worse than those of patients with HCC Huge tumor is an independent risk factor for initial extra-hepatic recurrence (Hazard ratio 7.86, P Huge HCC (≥10 cm) is an independent risk factor due to a high risk for initial extra-hepatic recurrence. Future systemic adjuvant therapy is needed for these patients. J. Surg. Oncol. 2017;115:324-329. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  18. Treatment of huge hypertensive putaminal hemorrhage by surgery and cerebrospinal fluid drainage. (United States)

    Zhang, Hong-Tian; Xue, Sha; Li, Pei-Jian; Fu, Yan-Bin; Xu, Ru-Xiang


    There is limited information available regarding the treatment of huge hypertensive putaminal hemorrhage (HPH). This study aimed to evaluate our experience of 33 patients with huge HPH who were treated by open surgery (decompressive craniectomy and hematoma evacuation) and external cerebrospinal fluid (CSF) drainage. We reviewed the records of 33 consecutive patients admitted to our hospital with huge HPH (≥ 60 cm(3)). All patients were treated by decompressive craniectomy, hematoma evacuation, and CSF drainage. Data collected included age, gender, blood pressure at admission, Glasgow Coma Scale (GCS) score, intracranial hemorrhage (ICH) location, ICH volume, degree of midline shift, presence/absence of basal cistern obliteration at admission and before surgery, and presence/absence of intraventricular hemorrhage (IVH). Outcome was assessed by the Glasgow Outcome Scale score at 30 days after surgery. The median GCS score was 5.0 at admission, and improved to 8.0 at 1 week after surgery. The median ICH volume was 95 cm(3) before surgery and 4 cm(3) after surgery. IVH was observed in 93.9% of patients. The overall survival rate to discharge was 75.6% (25/33), including 15.1% (4/33) with good function, 36.4% (12/33) with disability, and 24.3% (8/33) in a vegetative state. The mortality rate was 24.3% (8/33). Patients with right-sided ICH had better outcomes than those with left-sided ICH. No patients with GCS score ≤ 6 and ICH volume ≥ 90cm(3) at admission achieved good postoperative function. Operative time was significantly shorter with hematoma evacuation via the transcortical approach than via the transsylvian approach (3.41 ± 0.75 h vs. 4.14 ± 0.59 h, Phuge HPH by decompressive craniectomy, hematoma evacuation, and CSF drainage is life-saving. Patients with GCS score 7-8, ICH volume 60-90 cm(3), and right-sided ICH may achieve good recovery. The transcortical approach appears to be more effective than the transsylvian approach for rapid decompression of

  19. Fault Slip Embedded in Creep: Insight into Tectonic Tremors and Slow Slip Events from Acoustic and Optical Monitoring of Fractures (United States)

    Elkhoury, J. E.; Lengline, O.; Ampuero, J. P.; Schmittbuhl, J.


    Observations of temporal and spatial correlations between slow slip earthquakes and tectonic tremor activity suggest a physical relation between them. Early descriptions of mechanisms relating these phenomena simply attributed the relation between seismic and aseismic events to fluid mediated processes. More recent hypotheses suggest that tectonic tremors are bursts of seismic energy due to the rupturing of small asperities within slow slipping regions. Here we present laboratory results of a unique experimental setting aimed at understanding the response to transient loads of a system of small asperities embedded in creep as a model of tectonic tremor activity triggered by slow slip and modulated by tides. We performed mode I crack propagation experiments on glass bead blasted and annealed 2D interfaces of transparent material (Polymethylmethacrylate) where fracture fronts were confined to the 2D weakness plane of the heterogeneous interface. We monitored acoustic emissions (AE) with piezo-electric sensors surrounding the crack front line. We also optically monitored the rupture front line with up to 1000 frames per second. The experimental loading conditions produce quasi-static front propagation at slow average speeds. Image processing reveals de-pinning along the front that we characterize as intermittent opening during slow front propagation. AE locations strongly correlate to the spatiotemporal clustering of the de-penning events along the front. Moreover, this correlation is preserved at the time of imposed transient fluctuations in loading during front propagation. Using the analogy between mode I and modes II and III fractures, our results translate into intermittent slip on faults linked to clustering of seismic activity produced by the breakage of asperities embedded in creeping regions with no need of invoking fluid mediated processes. Thus our experiments help reveal the interplay between aseismic and seismic slip on faults. We also observe qualitative

  20. Offset of Latest Pleistocene Shoreface Reveals Slip Rate on the Hosgri Strike-Slip Fault, Offshore Central California (United States)

    Johnson, S. Y.; Hartwell, S. R.; Dartnell, P.


    The Hosgri fault is the southern part of the regional Hosgri-San Gregorio dextral strike-slip 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 slip 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 slip 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 slip rate indicates that the Hosgri system takes up the largest share of the strike-slip fault budget and is the most active strike-slip 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.

  1. Transformation of fault slip modes in laboratory experiments (United States)

    Martynov, Vasilii; Alexey, Ostapchuk; Markov, Vadim


    Slip mode of crust fault can vary because of many reasons. It's well known that fault structure, material of fault gouge, pore fluid et al. in many ways determines slip modes from creep and slow slip events to mega-earthquakes [1-3]. Therefore, the possibility of fault slip transformation due to external action is urgent question. There is popular and developing approach of fluid injection into central part of fault. The phenomenon of earthquakes induced due to pumping of water was investigated on small and large scales [4, 5]. In this work the laboratory experiments were conducted to study the evolution of the experimental fault slip when changing the properties of the interstitial fluid. The scheme of experiments is the classical slider-model set-up, in which the block under the shear force slips along the interface. In our experiments the plexiglas block 8x8x3 cm3 in size was put on the plexiglas base. The contact of the blocks was filled with a thin layer (about 3 mm thick) of a granular material. The normal load varied from 31 to 156 kPa. The shear load was applied through a spring with stiffness 60 kN/m, and the rate of spring deformation was 20 or 5 mcm/s. Two parameters were recorded during experiments: the shear force acting on the upper block (with an accuracy of 1 N) and its displacement relatively the base (with an accuracy of 0.1 μm). The gouge was composed of quartz sand (97.5%) and clay (2.5%). As a moisturizer were used different fluids with viscosity varying from 1 to 103 mPa x s. Different slip modes were simulated during slider-experiments. In our experiments slip mode is the act of instability manifested in an increase of slip velocity and a drop of shear stress acting on a movable block. The amplitude of a shear stress drop and the peak velocity of the upper block were chosen as the characteristics of the slip mode. In the laboratory experiments, slip events of one type can be achieved either as regularly recurring (regular mode) or as random

  2. Huge pelvic parachordoma: fine needle aspiration cytology and histological differential diagnosis

    Directory of Open Access Journals (Sweden)

    Mona A. Kandil


    Full Text Available Parachordoma is an extremely rare soft tissue tumor of unknown lineage. Parachordoma develops most often on the extremities. Only 2 cases have been reported as pelvic parachordoma. A 46-year old Egyptian woman with a huge painful pelvic mass was found to have a parachordoma with ectopic pelvic right kidney. There is only one report in the literature of fine needle aspiration cytology in this setting. The microscopic picture of parachordoma is not new to pathologists but the gross picture of this rare tumor has not previously been published; not even in the World Health Organization classification of soft tissues tumors. Diagnosis was confirmed by immuno-histochemistry. The patient is in good clinical condition without any evidence of recurrence or metastasis after 84 months of follow up.

  3. Shape Memory and Huge Superelasticity in Ni–Mn–Ga Glass-Coated Fibers

    Directory of Open Access Journals (Sweden)

    Lei Shao


    Full Text Available Ni–Mn–Ga polycrystalline alloy fibers with diameters of 33 μm are reported to exhibit significantly improved ductility and huge superelastic and shape memory strains in comparison to conventional brittle bulk polycrystalline alloys. Particularly, the recoverable strain of the Ni54.9–Mn23.5–Ga21.6 fiber can be as high as 10% at 40 °C. Such optimized behavior has been achieved by a suitable fabrication process via a glass-coating melt spinning method. The superelastic properties at different temperatures and the shape memory effect of Ni54.9–Mn23.5–Ga21.6 fibers were investigated.

  4. Tiny grains give huge gains: nanocrystal-based signal amplification for biomolecule detection. (United States)

    Tong, Sheng; Ren, Binbin; Zheng, Zhilan; Shen, Han; Bao, Gang


    Nanocrystals, despite their tiny sizes, contain thousands to millions of atoms. Here we show that the large number of atoms packed in each metallic nanocrystal can provide a huge gain in signal amplification for biomolecule detection. We have devised a highly sensitive, linear amplification scheme by integrating the dissolution of bound nanocrystals and metal-induced stoichiometric chromogenesis, and demonstrated that signal amplification is fully defined by the size and atom density of nanocrystals, which can be optimized through well-controlled nanocrystal synthesis. Further, the rich library of chromogenic reactions allows implementation of this scheme in various assay formats, as demonstrated by the iron oxide nanoparticle linked immunosorbent assay (ILISA) and blotting assay developed in this study. Our results indicate that, owing to the inherent simplicity, high sensitivity and repeatability, the nanocrystal based amplification scheme can significantly improve biomolecule quantification in both laboratory research and clinical diagnostics. This novel method adds a new dimension to current nanoparticle-based bioassays.

  5. Development of a huge varix following endovascular embolization for cerebellar arteriovenous malformation

    Energy Technology Data Exchange (ETDEWEB)

    Mineura, K.; Sasajima, H.; Itoh, Y.; Kowada, M. [Akita Univ. Hospital (Japan). Neurosurgical Service; Tomura, N. [Akita Univ. Hospital (Japan). Dept. of Radiology; Goto, K. [Iizuka Hospital, Fukuoka (Japan). Dept. of Interventional Neuroradiology


    We report on the case of a huge varix that developed after the endovascular embolization of a cerebellar arteriovenous malformation (AVM) with a single drainer. A 21-year-old male presented with trigeminal neuralgia which was caused by the dilated drainer of the AVM. A varix was found at the basal vein of Rosenthal 2 months after an initial stage of embolization with polyvinyl alcohol particles; it diminished after the surgical extirpation of the AVM. The varix formation might have been facilitated by the stenosis in the vein of Galen and by the dynamic changes that followed the embolization. This rare complication should be kept in mind when embolization is performed for AVMs with impaired venous outlets. (orig.).

  6. Huge spin-transfer torque in a magnetic tunnel junction by a superlattice barrier (United States)

    Chen, C. H.; Tseng, P.; Ko, C. W.; Hsueh, W. J.


    Huge spin-transfer torque (STT) in a magnetic tunnel junction (MTJ) achieved by superlattice barrier composed of alternate layers of a nonmagnetic metal and an insulator is proposed. The magnitude of the STT depends on the number of cells in the superlattice barrier and the nonmagnetic metal layer's thickness. The result shows that the STT of the novel superlattice-barrier MTJ can reach values up to four orders of magnitude greater than those of traditional single-barrier stacks based on three cells superlattice by designing the nonmagnetic metal layer's thickness. In addition, the spin-transfer torque of the proposed MTJ can also be thousands of magnitude greater than those of traditional double-barrier MTJs.

  7. Unusual Large Sporadic Angiomyolipoma Co-existing with Huge Simple Renal Cyst

    Directory of Open Access Journals (Sweden)

    Sunil V Jagtap


    Full Text Available Renal Angiomyolipoma (AML is an unusual benign mesenchymal tumor with no malignant potential. It is composed of adipose tissue, smooth muscle and abnormal thick walled blood vessels. It can occur sporadically or may be associated with tuberous sclerosis. Sporadic angiomyolipoma (AML coexisting with simple renal cyst is extremely rare and only one case report is available in the literature. In our case, unique combination of sporadic AML along with simple renal cyst with huge size and weight was noted. To the best of our knowledge, ours is the second such case and first case from India. Due to its large size, complete nephrectomy was performed to avoid chances of rupture and retroperitoneal hemorrhage. Post-operative period was uneventful and the patient ahs been on regular follow-up.

  8. Bilateral ureteral complete obstruction with huge spontaneous urinoma formation in a patient with advanced bladder cancer. (United States)

    Jou, Yeong-Chin; Shen, Cheng-Huang; Cheng, Ming-Chin; Lin, Chang-Te; Chen, Pi-Che


    Spontaneous rupture of the collecting system with extravasation of urine and urinoma formation is usually associated with urinary tract obstruction by a ureteral calculus. Tumor growth is an extremely rare cause of urinary extravasation. Here we report a case of bilateral obstructive uropathy with a huge spontaneous left retroperitoneal urinoma caused by advanced infiltrative transitional cell carcinoma of the urinary bladder. The point of leakage was located in the left renal pelvis. The urinary leakage ceased after percutaneous nephrostomy drainage, and the patient subsequently underwent radical cystoprostatectomy. Histopathology revealed a high-grade urothelial carcinoma of the urinary bladder with pelvic lymph node metastasis. The patient refused any adjuvant treatment and expired 6 months after the operation from disseminated metastasis from bladder cancer. Copyright © 2011. Published by Elsevier B.V.

  9. Bilateral ureteral complete obstruction with huge spontaneous urinoma formation in a patient with advanced bladder cancer

    Directory of Open Access Journals (Sweden)

    Yeong-Chin Jou


    Full Text Available Spontaneous rupture of the collecting system with extravasation of urine and urinoma formation is usually associated with urinary tract obstruction by a ureteral calculus. Tumor growth is an extremely rare cause of urinary extravasation. Here we report a case of bilateral obstructive uropathy with a huge spontaneous left retroperitoneal urinoma caused by advanced infiltrative transitional cell carcinoma of the urinary bladder. The point of leakage was located in the left renal pelvis. The urinary leakage ceased after percutaneous nephrostomy drainage, and the patient subsequently underwent radical cystoprostatectomy. Histopathology revealed a high-grade urothelial carcinoma of the urinary bladder with pelvic lymph node metastasis. The patient refused any adjuvant treatment and expired 6 months after the operation from disseminated metastasis from bladder cancer.


    Directory of Open Access Journals (Sweden)

    T N Chiranjeevi


    Full Text Available Personal recommendation system is one which gives better and preferential recommendation to the users to satisfy their personalized requirements such as practical applications like Webpage Preferences, Sport Videos preferences, Stock selection based on price, TV preferences, Hotel preferences, books, Mobile phones, CDs and various other products now use recommender systems. The existing Pearson Correlation Coefficient (PCC and item-based algorithm using PCC, are called as UPCC and IPCC respectively. These systems are mainly based on only the rating services and does not consider the user personal preferences, they simply just give the result based on the ratings. As the size of data increases it will give the recommendations based on the top rated services and it will miss out most of user preferences. These are main drawbacks in the existing system which will give same results to the users based on some evaluations and rankings or rating service, they will neglect the user preferences and necessities. To address this problem we propose a new approach called, Personnel Recommendation System (PRS for huge data analysis using Porter Stemmer to solve the above challenges. In the proposed system it provides a personalized service recommendation list to the users and recommends the most useful services to the users which will increase the accuracy and efficiency in searching better services. Particularly, a set of suggestions or keywords are provided to indicate user preferences and we used Collaborative Filtering and Porter Stemmer algorithm which gives a suitable recommendations to the users. In real, the broad experiments are conducted on the huge database which is available in real world, and outcome shows that our proposed personal recommender method extensively improves the precision and efficiency of service recommender system over the KASR method. In our approach mainly consider the user preferences so it will not miss out the any of the data

  11. Huge epithelial nonparasitic splenic cyst: A case report and a review of treatment methods. (United States)

    Farhangi, Bahman; Farhangi, Arezo; Firouzjahi, Alireza; Jahed, Babak


    Splenic cysts are rare in all age groups and there are a few reports in the world literature. Primary cysts occur most frequently in children and young adults, comprising around 25% of all nonparasitic splenic cysts. Various techniques are suggested for the treatment of splenic cysts. In this case report, a huge epithelial splenic cyst in a 17-year-old female is presented and different treatment methods of splenic cysts are evaluated. A 17-year-old female presented with progressive abdominal mass in left upper quadrant associated with abdominal pain and food intolerance of duration of several months. There was no history of trauma. On physical examination, there was a huge mass located in the upper left side of abdomen. Computerized tomography scan revealed that a large cystic lesion had occupied the spleen with dimensions of 32x21xI5.6 cm. After patient preparation laparotomy was performed and complete cyst excision was done with splenectomy, patient was discharged after 2 days. This is a report of a case of epithelial splenic cyst of the spleen in a 17-year old female. The management of splenic cysts continues to evolve and the optimum treatment of patients with nonparasitic splenic cysts is controversial, as a principle preservation technique of the spleen with minimally invasive methods such as laparoscopy is preferred to splenectomy with the exception of very large cysts and when splenic hilum is involved in cyst wall. However, significant cyst recurrences were encountered with these techniques. Recently open partial splenectomy has been proposed as a safe and effective method in the management of NPSCs it ensures complete cyst removal, lack of cyst recurrence, and preservation of the spleen functions.

  12. Bioinspired oil strider floating at the oil/water interface supported by huge superoleophobic force. (United States)

    Liu, Xueli; Gao, Jun; Xue, Zhongxin; Chen, Li; Lin, Ling; Jiang, Lei; Wang, Shutao


    Oil pollution to aquatic devices, especially to those oil-cleaning devices and equipment-repairing robots during oil spill accidents, has drawn great attention and remains an urgent problem to be resolved. Developing devices that can move freely in an oil/water system without contamination from oil has both scientific and practical importance. In nature, the insect water strider can float on water by utilizing the superhydrophobic supporting force received by its legs. Inspired by this unique floating phenomenon, in this article, we designed a model device named "oil strider" that could float stably at the oil/water interface without contamination by oil. The floating capability of the oil strider originated from the huge underwater superoleophobic supporting force its "legs" received. We prepared the micro/nanohierarchical structured copper-oxide-coated copper wires, acting as the artificial legs of oil strider, by a simple base-corrosion process. The surface structures and hydrophilic chemical components of the coatings on copper wires induced the huge superoleophobic force at the oil/water interface, to support the oil strider from sinking into the oil. Experimental results and theoretical analysis demonstrate that this supporting force is mainly composed of three parts: the buoyancy force, the curvature force, and the deformation force. We anticipate that this artificial oil strider will provide a guide for the design of smart aquatic devices that can move freely in an oil/water system with excellent oil repellent capability, and be helpful in practical situations such as oil handling and oil spill cleanup.

  13. PTHA Slip Models in the Aftermath of the 2011 Tohoku Earthquake and Tsunami (United States)

    Geist, E. L.; Parsons, T.; Oglesby, D. D.


    Inter-plate thrust slip models used in Probabilistic Tsunami Hazard Analysis (PTHA) are re-evaluated in light of the 2011 Tohoku earthquake and tsunami. Whereas recurrence is typically linked to seismic moment in PTHA, the magnitude and distribution of slip are the primary variables that affect tsunami generation. Because of the self-similar nature of rupture, the slip model is dependent on other scaling relationships, such as magnitude-area and magnitude-mean slip. In the past, various slip models have been used to calculate tsunami generation, ranging from uniform slip to stochastic models. Uniform slip models systematically underestimate the amplitude and leading-wave steepness for the local, broadside tsunami. Stochastic slip models, constrained by the seismic displacement spectrum, produce a range of possible slip distributions for a given seismic moment and slip spectrum and more accurately represent heterogeneous earthquake ruptures. Conventional stochastic slip models based on a k-2 slip spectrum and Gaussian random variables result in a coefficient of variation (c.v.) approximately equal to 0.5. However, slip inversion results of recent tsunamigenic earthquakes indicate that the observed c.v. is significantly greater than 0.5. This is particularly evident for the 2011 Tohoku earthquake, in which the c.v. for slip is approximately 1.0. Recent updates to the stochastic slip model can retain a k-2 slip spectrum, but use non-Gaussian distributed random variables. The updated stochastic slip model is more consistent with the observed fluctuations in slip. We investigate how these models can be applied in a PTHA framework. In addition, dynamic effects such as amplification of slip near the free surface, partitioning of slip between different overlapping fault segments, and dynamic overshoot can strongly modify the slip pattern in ways that may be correlated with geometrical and frictional properties on the fault; such effects potentially may be predictable prior

  14. Sensitivity of vehicle handling to combined slip tyre characteristics

    NARCIS (Netherlands)

    Jansen, S.T.H.; Oosten, J.J.M. van; Pacejka, H.B.; Pauwelussen, J.P.


    The sensitivity of vehicle handling to combined slip tyre characteristics is investigated using two simulation models with different interaction between lateral and longitudinal tyre forces. The standard method for the braking in a turn test is simulated with both models, and differences in the outc

  15. Friction at seismic slip rates: testing thermal weakening models experimentally (United States)

    Nielsen, S. B.; Spagnuolo, E.; Violay, M.; Di Toro, G.


    Recent experiments systematically explore rock friction under crustal earthquake conditions (fast slip rate 1desing an efficient and accurate wavenumber approximation for a solution of the temperature evolution on the fault. Finally, we propose a compact and paractical model based on a small number of memory variables for the implementation of thermal weakening friction in seismic fault simulations.

  16. Quantifying effective slip length over micropatterned hydrophobic surfaces

    NARCIS (Netherlands)

    Tsai, Peichun; Peters, Alisia M.; Pirat, Christophe; Wessling, Matthias; Lammertink, Rob G.H.; Lohse, Detlef


    We employ microparticle image velocimetry to investigate laminar microflows in hydrophobic microstructured channels, in particular the slip length. These microchannels consist of longitudinal microgrooves, which can trap air and prompt a shear-free boundary condition and thus slippage enhancement. O

  17. Analysing earthquake slip models with the spatial prediction comparison test

    KAUST Repository

    Zhang, L.


    Earthquake rupture models inferred from inversions of geophysical and/or geodetic data exhibit remarkable variability due to uncertainties in modelling assumptions, the use of different inversion algorithms, or variations in data selection and data processing. A robust statistical comparison of different rupture models obtained for a single earthquake is needed to quantify the intra-event variability, both for benchmark exercises and for real earthquakes. The same approach may be useful to characterize (dis-)similarities in events that are typically grouped into a common class of events (e.g. moderate-size crustal strike-slip earthquakes or tsunamigenic large subduction earthquakes). For this purpose, we examine the performance of the spatial prediction comparison test (SPCT), a statistical test developed to compare spatial (random) fields by means of a chosen loss function that describes an error relation between a 2-D field (‘model’) and a reference model. We implement and calibrate the SPCT approach for a suite of synthetic 2-D slip distributions, generated as spatial random fields with various characteristics, and then apply the method to results of a benchmark inversion exercise with known solution. We find the SPCT to be sensitive to different spatial correlations lengths, and different heterogeneity levels of the slip distributions. The SPCT approach proves to be a simple and effective tool for ranking the slip models with respect to a reference model.

  18. Determination of the of rate cross slip of screw dislocations

    DEFF Research Database (Denmark)

    Vegge, Tejs; Rasmussen, Torben; Leffers, Torben;


    The rate for cross slip of screw dislocations during annihilation of screw dipoles in copper is determined by molecular dynamics simulations. The temperature dependence of the rate is seen to obey an Arrhenius behavior in the investigated temperature range: 225-375 K. The activation energy...

  19. Interfacial Slip in Soap Films with Hydrosoluble Polymer (United States)

    Adelizzi, E. A.; Berg, S.; Troian, S. M.


    The thickness of a Newtonian soap film entrained at small capillary number should scale as Ca^2/3 provided the bounding surfaces are rigid. Previous studies show that soap films containing associating, low concentration, high molecular weight (M_w) polymer exhibit strong deviations from this scaling. We report results by laser interferometry of the entrained film thickness for the associating pair SDS/PEO over a large range in polymer molecular weight. Direct comparison to predictions of hydrodynamic models based on viscoelastic behavior shows poor agreement.Modification of the Frankel analysis to account for mobile films through a Navier slip condition yields good agreement. In addition, the slip length Ls increases as M_w^3/5, consistent with a correlation based on a polymer chain size for freely jointed chains with excluded volume effects. Although developed to explain slip at liquid-solid interfaces, the Tolstoi-Larson prediction that Ls scales as the polymer size agrees favorably with our results. Whether the slip behavior is due to Marangoni effects cannot be ruled out.

  20. Investigation of torque control using a variable slip induction generator

    Energy Technology Data Exchange (ETDEWEB)

    Bossanyi, E.A.; Gamble, C.R.


    An investigation of the possibilities of using a variable slip induction generator to control wind turbine transmission torque has been carried out. Such a generator consists of a wound rotor induction generator with its rotor winding connected to an external variable resistance circuit. By controlling the external resistance, the torque-slip characteristic of the generator can be modified, allowing efficient, low-slip operation below rated wind speed and compliant, high-slip operation above rated, where the additional losses are of no consequence but the resulting compliance allows a much reduced duty to be specified for the transmission and gearbox. A number of hardware options have been investigated for the variable resistance rotor circuit, the main options being either a rectifier and DC chopper or an AC regulator. Both of these options use semiconductor switching devices, for which the relative merits of thyristors, MOSFETs, GTOs and transistors have been investigated. A favoured scheme consisting of an AC regulator using GTOs has been provisionally selected. This choice uses some non-standard equipment but is expected to give negligible problems with harmonics. A comprehensive simulation model has been set up and used to investigate the behaviour of the whole system. (author).

  1. Dynamic Action Units Slip in Speech Production Errors (United States)

    Goldstein, Louis; Pouplier, Marianne; Chen, Larissa; Saltzman, Elliot; Byrd, Dani


    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--"slips of the tongue". The present study reports, for…

  2. Slip and flow dynamics of polydisperse thin polystyrene films. (United States)

    Sabzevari, Seyed Mostafa; McGraw, Joshua D.; Jacobs, Karin; Wood-Adams, Paula M.


    We investigate the slip of binary and ternary mixtures of nearly monodisperse polystyrene samples on Teflon-coated (AF2400) silicon wafers using dewetting experiments. Binary mixtures of long and short chains along with ternary mixtures with a fixed weight-average molecular weight Mw but different number-average molecular weight Mn were prepared. Thin films of ca. 200 nm were spin coated on mica from polymer solutions and transferred to Teflon substrates. Above the glass transition temperature Tg the films break up via nucleation and growth of holes. The hole growth rate and rim morphology are monitored as a function of Mn and annealing protocol of the films before transfer to Teflon substrates. Slip properties, accessed using hydrodynamic models, and flow dynamics are then examined and compared. We found that the rim morphology and slip of polystyrene blends on Teflon depends on the molecular weight distribution. Similarly, flow dynamics is affected by the presence of short chains in mixture. Moreover, we can provoke differences in slip by choosing appropriate annealing and film transfer protocols for PS films that have first been spin cast on mica surfaces.

  3. Analytical solutions for squeeze flow with partial wall slip

    DEFF Research Database (Denmark)

    Laun, HM; Rady, M; Hassager, Ole


    Squeeze flow between parallel plates of a purely viscous material is considered for small gaps both for a Newtonian and power law fluid with partial wall slip. The results for the squeeze force as a function of the squeezing speed reduce to the Stefan and Scott equations in the no slip limit......, respectively. The slip velocity at the plate increases linearly with the radius up to the rim slip velocity upsilon(s). For small Saps H, the resulting apparent Newtonian rim shear rate-measured for a constant rim shear stress, i.e. an imposed force increasing proportional to 1/H-yields a straight line...... if plotted versus 1/H. The slope of the straight line is equal to 6 upsilon(s) whereas the intersect with the ordinate yields the effective Newtonian rim shear rate to be converted into the true rim shear rate by means of the power law exponent. The advantage of the new technique is the separation of bulk...

  4. Nucleation and growth of strike slip faults in granite. (United States)

    Segall, P.; Pollard, D.P.


    Fractures within granodiorite of the central Sierra Nevada, California, were studied to elucidate the mechanics of faulting in crystalline rocks, with emphasis on the nucleation of new fault surfaces and their subsequent propagation and growth. Within the study area the fractures form a single, subparallel array which strikes N50o-70oE and dips steeply to the S. Some of these fractures are identified as joints because displacements across the fracture surfaces exhibit dilation but no slip. The joints are filled with undeformed minerals, including epidote and chlorite. Other fractures are identified as small faults because they display left-lateral strike slip separations of up to 2m. Slickensides, developed on fault surfaces, plunge 0o-20o to the E. The faults occur parallel to, and in the same outcrop with, the joints. The faults are filled with epidote, chlorite, and quartz, which exhibit textural evidence of shear deformation. These observations indicate that the strike slip faults nucleated on earlier formed, mineral filled joints. Secondary, dilational fractures propagated from near the ends of some small faults contemporaneously with the left-lateral slip on the faults. These fractures trend 25o+ or -10o from the fault planes, parallel to the direction of inferred local maximum compressive stress. The faults did not propagate into intact rock in their own planes as shear fractures. -from Authors

  5. On the Modeling of Contact Interfaces with Frictional Slips

    Directory of Open Access Journals (Sweden)

    Ligia Munteanu


    Full Text Available The paper analyses the contact interfaces between the scatterers and the matrix into the sonic composites, in the presence of the frictional slips. The sonic composite is a sonic liner designed in order to provide suppression of unwanted noise for jet engines, with emphases on the nacelle of turbofan engines for commercial aircraft.

  6. Scaling of the critical slip distance in granular layers

    CERN Document Server

    Hatano, Takahiro


    We investigate the nature of friction in granular layers by means of numerical simulation focusing on the critical slip distance, over which the system relaxes to a new stationary state. Analyzing a transient process in which the sliding velocity is instantaneously changed, we find that the critical slip distance is proportional to the sliding velocity. We thus define the relaxation time, which is independent of the sliding velocity. It is found that the relaxation time is proportional to the layer thickness and inversely proportional to the square root of the pressure. An evolution law for the relaxation process is proposed, which does not contain any length constants describing the surface geometry but the relaxation time of the bulk granular matter. As a result, the critical slip distance is scaled with a typical length scale of a system. It is proportional to the layer thickness in an instantaneous velocity change experiment, whereas it is scaled with the total slip distance in a spring-block system on gr...

  7. Evidence Based Prevention of Occupational Slips, Trips and Falls

    DEFF Research Database (Denmark)

    Jensen, Olaf Chresten


    It is estimated that about one third of the compensated occupational injuries and half of the most serious occupational injuries in merchant seafaring are related to slips, trips and falls (STF)-events. Among the elderly, STF is the risk factor that causes the largest number of inpatient days...

  8. Micro-vibration-based slip detection in tactile force sensors. (United States)

    Fernandez, Raul; Payo, Ismael; Vazquez, Andres S; Becedas, Jonathan


    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, slip detection is also crucial to successfully manipulate an object. Several approaches have appeared to detect slipping, 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 slipping in other force sensors based on flexible parts. In particular, we show and compare the slip 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.

  9. Flash Heating of Crustal Rocks at Seismic Slip Rates (United States)

    Goldsby, D. L.; Spagnuolo, E.; Smith, S. A.; Beeler, N. M.; Tullis, T. E.; Di Toro, G.; Nielsen, S. B.


    Recent experiments have demonstrated that rocks undergo extreme frictional weakening at near-earthquake slip rates due to the thermal degradation of the strength, or even melting, of microscopic asperity contacts on their sliding surfaces (Goldsby and Tullis, 2012). These previous experiments, conducted at constant normal stress and slip rates of up to ~0.4 m/s, revealed a 1/V dependence of friction on slip rate above a characteristic weakening velocity, Vw, in accord with theories of flash heating (e.g., Rice, 2006). The weakening velocity obtains values of ~0.1 m/s for many crustal silicate rocks (Goldsby and Tullis, 2012). Here we test two further predictions of flash-heating theory - that the degree of weakening saturates at slip rates approaching 1 m/s, and that the weakening behavior due to flash heating is independent of normal stress - by testing samples at slip rates of up to 1 m/s at different normal stresses. Experiments were conducted in a 1-atm, high-velocity friction apparatus at the Istituto Nazionale di Geofisica e Vulcanologia in Rome. A sample consisted of a pair of hollow cylinders of Westerly granite or Frederick diabase subjected to a nominally constant normal stress of from 1 to 30 MPa and subjected to a variety of rate-stepping sequences. Data were acquired at rates of up to 1 MHz. As predicted, the experiments demonstrate that the degree of weakening due to flash heating saturates at slip rates approaching 1 m/s; in a few cases, friction even increases slightly with increasing slip rate near 1 m/s. The experiments also demonstrate that, within the scatter of the data, the value of Vw and the friction coefficient in the weakened state is independent of normal stress, the expected result if average contact sizes and contact stresses are independent of normal stress. The data thus further corroborate existing theories and experimental data for flash heating, allowing for a more reliable determination of the conditions under which flash heating

  10. The 3-D surface deformation, coseismic fault slip and after-slip of the 2010 Mw6.9 Yushu earthquake, Tibet, China (United States)

    Zhang, Guohong; Shan, Xinjian; Feng, Guangcai


    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 slip mechanism. The horizontal deformation is basically consistent with a sinistral slip 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 slip and early after-slip of the Yushu event. Our inversion results show major coseismic left lateral strike slip with only minor thrust component. The after-slip model fills most of the slip gaps left by the coseismic fault slip and finds a complementary slip distribution to the coseismic fault slip, which is a good indicator that future earthquake potential on the Yushu segment has been significantly reduced.

  11. Direct measurement of wall slip and slip layer thickness of non-Brownian hard-sphere suspensions in rectangular channel flows (United States)

    Jesinghausen, Steffen; Weiffen, Rene; Schmid, Hans-Joachim


    Wall slip 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 slip or slip due to particle migration have to be taken into account. Furthermore, suspensions themselves show many flow anomalies and the isolation of slip is complicated. In order to develop working physical models, further insight is necessary. In this work, we measured experimentally the wall slip velocities of different highly filled suspensions in a rectangular slit die directly with respect to the particle concentration and the particle size. The slip 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 slip 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 slip. Concerning the shear stress, there seem to be two regions of slip with different physical characteristics. Furthermore, we estimated the slip 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.

  12. Comparisons of Limit Analysis Solutions and Random Search Solutions on Slope Critical Slip SUrface

    Institute of Scientific and Technical Information of China (English)



    The object of this paper is twofold:to present a kinematics limit analysis for assessing the safety of slope or its critical slip surface,and to compare the searched slip surface with that by limit analysis.

  13. Rapid screening of the heterogeneity of DNA methylation by single-strand conformation polymorphism and CE-LIF in the presence of electro-osmotic flow. (United States)

    Yu, Meng-Hsuan; Huang, Ya-Chi; Chang, Po-Ling


    DNA methylation is a complex event in epigenetic studies because of both the large CpG islands present upstream of the promoter region and the different distribution of DNA methylation despite similar methylation levels. For this reason, we proposed a fast, cost-effective method for the screening of DNA methylation based on SSCP and CE-LIF. In this study, the PCR products that were amplified from bisulfite-treated genomic DNA were denatured at 94°C, followed by immediate chilling in ice water to form the ssDNA. The ssDNA were separated by 1.5% poly(ethylene oxide) (Mavg 8 000 000 Da) in the presence of EOF according to the different conformations represented by their unique methylation states. This result demonstrated that four hepatocellular carcinoma cell lines represented a different heterogeneity of DNA methylation and could be distinguished by SSCP-CE. The results obtained from SSCP-CE also corresponded with those obtained from combined bisulfide restriction analysis and methylation-sensitive high-resolution melting analysis. Therefore, the proposed SSCP-CE method may potentially be used for rapid screening for determination of the heterogeneity of DNA methylation in further epigenetic studies and clinical diagnosis.

  14. Induced- and alternating-current electro-osmotic control of the diffusion layer growth in a microchannel-membrane interface device (United States)

    Park, Sinwook; Yossifon, Gilad


    The passage of an electric current through an ionic permselective medium under an applied electric field is characterized by the formation of ionic concentration gradients, which result in regions of depleted and enriched ionic concentration at opposite ends of the medium. Induced-current electro-osmosis (ICEO) and alternating-current-electro-osmosis (ACEO) are shown to control the growth of the diffusion layer (DL) which, in turn, controls the diffusion limited ion transport through the microchannel-membrane system. We fabricated and tested devices made of a Nafion membrane connecting two opposite PDMS microchannels. An interdigitated electrode array was embedded within the microchannel with various distances from the microchannel-membrane interface. The induced ICEO (floating electrodes) / ACEO (active electrodes) vortices formed at the electrode array stir the fluid and thereby suppress the growth of the DL. The intensity of the ACEO vortices is controlled by either varying the voltage amplitude or the frequency, each having its own unique effect. Enhancement of the limiting current by on-demand control of the diffusion length is of importance in on-chip electro-dialysis, desalination and preconcentration of analytes.

  15. Availability of electro-osmotic process for treating contaminated clays with gasoline; Viabiliadade do processo eletro-osmotico para remediacao de solo argiloso contaminado com gasolina

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Veronica E.; Neri, Katya D. [Universidade Estadual da Paraiba (UEPB), Joao Pessoa, PB (Brazil); Vilar, Eudesio O. [Universidade Federal de Campina Grande (UFCG), PB (Brazil)


    The electrochemical mobilization of organic compounds occurs through simultaneously drag with the interstitial fluid (electrosmosis). For this study of electroremediation it was used a rectangular reactor filled with 1700 g of clay mixture (47% fine sand, 48% bentonite and 5% vermiculite) previously contaminated with gasoline. DSA - electrodes were inserted directly into the soil. The results of efficiency of mobilization to several initial soil moisture content (20-50%), time of experiment (48 - 72 h) and intensity of electric field (1-3 V/Cm) were confronted with the changes of pH, resulting from electrosmosis process. It was observed that the mobilization of the contaminant increased by increasing the time and intensity of electric field, in lower initial moisture. The tests results show that the best conditions for processing are 72 hours, 20% humidity and 3V/cm. In those circumstances it was possible to mobilize 46% of the initial concentration of gasoline, percentage found near the anode. The electrolysis provided soil acidification. It was found soil pH values above 11 near the cathode and below 2 neighbour to the anode, a factor that contributed to produce an electrosmosis reverse flow (cathode-anode flow direction). It is concluded that the mobilization by electrochemistry phenomena of gasoline in clay soil is possible, its efficiency, however depends on the proper control of the conditions of the process including pH (author)

  16. Analysis of metal ions migration to determine electro-osmotic flow for the in-situ cleanup of a tar-contaminated site

    NARCIS (Netherlands)

    Lima, A.T.; Rodrigues, P.C.; Loch, J.P.G.


    An electro-osmosis experiment was set up on a former asphalt factory site, which is currently contaminated by tar, in Olst, the Netherlands. The main goal of this experiment was to remove polycyclic aromatic hydrocarbons (PAHs) from a contaminated clay layer by applying an electric gradient. But bef

  17. A slow slip event along the northern Ecuadorian subduction zone (United States)

    Nocquet, J.; Mothes, P. A.; Vallee, M.; Regnier, M.


    Rapid subduction of the Nazca plate beneath the Ecuador-Colombia margin (~58 mm/yr) has produced one of the largest megathrust earthquake sequence during the last century. The 500-km-long rupture zone of the 1906 (Mw = 8.8) event was partially reactivated by three thrust events; in 1942 (Mw = 7.8), 1958 (Mw = 7.7), and 1979 (Mw = 8.2), whose rupture zones abut one another. New continuously-recording GPS stations installed along the Ecuadorian coast, together with campaign sites observed since 1994 indicate that the current velocities results from the superimposition of a NNE motion the crustal North Andean Block occurring at ~8 mm/yr in Ecuador and the elastic deformation involved by partial locking of the subduction interface. We first estimate the long-term kinematics of the North Andean block in a joint inversion including GPS data, earthquake slip vectors and quaternary slip rates on major faults. The inversion provides a Euler pole located at long. -107.8°E, lat. 36.2°N, 0.091°/Ma and indicates little internal deformation of the North Andean Block (wrms=1.3 mm/yr). Residual velocities with respect to the North Andean Block are then modeled in terms of elastic locking along the subduction interface. Models indicate that the subduction interface is partially locked (50%) up to a depth of 40 km. Finally, we report a transient event that occurred in early 2008 near the Ecuador-Colombia border. The magnitude of the trenchward displacement is 13 mm, with uplift of similar magnitude. While the total duration of the slip event is 5 months, the horizontal time series clearly shows two sub-phases of slip with approximatively similar magnitud of displacement and duration, separated by 6 weeks. Modelling indicates that the slip occurs at 40 km depth, immediately below downdip extension of the locked zone.

  18. Slip and fall risk on ice and snow:identification, evaluation and prevention


    Gao, Chuansi


    Slip and fall accidents and associated injuries on ice and snow are prevalent among outdoor workers and the general public in winter in many regions of the world. To understand and tackle this multi-factorial problem, a multidisciplinary approach was used to identify and evaluate slip and fall risks, and to propose recommendations for prevention of slips and falls on icy and snowy surfaces. Objectives were to present a systems perspective of slip and fall accidents and related risk factors; t...

  19. The platelet-to-lymphocyte ratio predicts poor survival in patients with huge hepatocellular carcinoma that received transarterial chemoembolization. (United States)

    Xue, Tong-Chun; Jia, Qing-An; Ge, Ning-Ling; Zhang, Bo-Heng; Wang, Yan-Hong; Ren, Zheng-Gang; Ye, Sheng-Long


    Inflammation is particularly strong in huge hepatocellular carcinoma (HCC). However, it is unclear whether the platelet-to-lymphocyte ratio (PLR), as an inflammatory-related marker, can predict survival of patients with huge HCC. In this study, we enrolled 291 patients with huge HCC (diameter over 10 cm) who were undergoing repeated transarterial chemoembolization (TACE) at our institute. The baseline PLR was calculated from complete serum blood counts before the first chemoembolization. We found that a baseline PLR cutoff value over 150 best predicted huge HCC survival. The 12, 24, and 36 months survival rates in the high PLR group (22.6, 8.1, and 4.1 %, respectively) were significantly lower than in the low PLR group (35.6, 22.4, and 14 %, respectively). Thus, a significant difference was found in overall survival (log-rank test, p huge HCC, a high baseline PLR is a useful predictor of poor survival in patients undergoing chemoembolization. Additional anti-inflammatory or anti-platelet treatments, in combination with TACE, may improve survival in HCC patients with high PLR.

  20. The value of a formula including haematocrit, blood urea and gender (HUGE) as a screening test for chronic renal insufficiency. (United States)

    Alvarez-Gregori, J A; Robles, N R; Mena, C; Ardanuy, R; Jauregui, R; Macas-Nu Nunez, J F


    Despite increasing use in clinical practice, an estimated glomerular filtration rate value (eGFR) of HUGE formula. A formula including haematocrit , blood urea, and gender (HUGE), diagnoses CRI regardless of the variables of age, blood creatinine, creatinine clearance, or other eGFR. The HUGE formula is: L = 2.505458 - (0.264418 x Hematocrit) + (0.118100 x Urea) [+ 1.383960 if male]. If L is a negative number the individual does not have CRI; if L is a positive number, CRI is present. Our data demonstrate that the HUGE formula is more reliable than MDRD and CKD-EPI, particularly in persons aged over 70. Our HUGE screening formula offers a straightforward, easily available and inexpensive method for differentiating between CRI and eGFR < 60 ml/min/1.73 m2 that will prevent a considerable number of aged healthy persons, as much as 1.700.000 in Spain and 2.600.000 in U.K., to be excluded from clinical assays or treatments contraindicated in CRI.


    Shi, Jiandang; Zhao, Chen; Ding, Huiqiang; Fu, Bin; Niu, Ningkui; Yue, Xuefeng; Yang, Zongqiang; He, Yin


    To investigate the surgical outcome of combined posterior and anterior approaches for the resection of thoracolumbar spinal canal huge dumbbell-shaped tumor. Between January 2009 and March 2015, 12 patients with thoracolumbar spinal canal huge dumbbell-shaped tumor were treated by posterior approach and anterolateral approach through diaphragmatic crura and thoracoabdominal incision for complete resection. There were 9 males and 3 females, with an average age of 45 years (range, 30-65 years). The disease duration was 8-64 weeks (mean, 12.7 weeks). The tumor was located at T(12), L1 in 6 cases, at L(1,2) in 5 cases, and at L(2,3) in 1 case. The tumor size ranged from 4.3 cm x 4.0 cm x 3.5 cm to 7.5 cm x 6.3 cm x 6.0 cm. According to tumor outside the spinal involvement scope and site and based on the typing of Eden, 5 cases were rated as type b, 2 cases as type d, 4 cases as type e, and 1 case as type f in the transverse direction; two segments were involved in 8 cases, and more than two segments in 4 cases. The degree of tumor excision, tumor recurrence, and the spine stability were observed during follow-up. The verbal rating scale (VRS) was used to evaluate pain improvement. The average surgical time was 170 minutes (range, 150-230 minutes); the average intraoperative blood loss was 350 mL (range, 270-600 mL). All incisions healed by first intention, and no thoracic cavity infection and other operation related complication occurred. Of 12 cases, 10 were histologically confirmed as schwannoma, and 2 as neurofibroma. The patients were followed up 6 months to 6 years (mean, 31 months). Neurological symptoms were significantly improved in all patients, without lower back soreness. The thoracolumbar X-ray film and MRI showed no tumor residue. No tumor recurrence, internal fixator loosening, scoliosis, and other complications were observed during follow-up. VRS at last follow-up was significantly improved to grade 0 (10 cases) or grade 1 (2 cases) from preoperative

  2. Role of multiscale heterogeneity in fault slip from quasi-static numerical simulations (United States)

    Aochi, Hideo; Ide, Satoshi


    Quasi-static numerical simulations of slip along a fault interface characterized by multiscale heterogeneity (fractal patch model) are carried out under the assumption that the characteristic distance in the slip-dependent frictional law is scale-dependent. We also consider slip-dependent stress accumulation on patches prior to the weakening process. When two patches of different size are superposed, the slip rate of the smaller patch is reduced when the stress is increased on the surrounding large patch. In the case of many patches over a range of scales, the slip rate on the smaller patches becomes significant in terms of both its amplitude and frequency. Peaks in slip rate are controlled by the surrounding larger patches, which may also be responsible for the segmentation of slip sequences. The use of an explicit slip-strengthening-then-weakening frictional behavior highlights that the strengthening process behind small patches weakens their interaction and reduces the peaks in slip rate, while the slip deficit continues to accumulate in the background. Therefore, it may be possible to image the progress of slip deficit at larger scales if the changes in slip activity on small patches are detectable.

  3. Stick-slip to sliding transition of dynamic contact lines under AC electrowetting

    NARCIS (Netherlands)

    Mannetje, 't D.J.C.M.; Mugele, F.; Ende, van den D.


    We show that at low velocities the dynamics of a contact line of a water drop moving over a Teflon-like surface under ac electrowetting must be described as stick–slip motion, rather than one continuous movement. At high velocities we observe a transition to a slipping regime. In the slipping regime

  4. Partial reactivation of a huge deep-seated ancient rock slide: recognition, formation mechanism, and stability (United States)

    Tang, Minggao; Xu, Qiang; Li, Yusheng; Huang, Runqiu; Rengers, Niek; Zhu, Xing


    About 18 years ago, a large-scale discontinuous layer in properties and colour was found in the new Fengjie town at the shore of the Three Gorges Reservoir area in China. There are many resettled residents and buildings on the sloping area, the safety of which is potentially affected by this layer, so it has become the focus of attention. Before this study started there were two viewpoints regarding the origin of this layer. One was that is was from a huge ancient slide and the other was that is was from a fault graben. In order to find out how it was formed and to be able to carry out a stability analysis of the slope the authors have carried out a research program, including geological field investigations and mapping, a deep drilling hole, a geotechnical centrifuge model test, and a simulation analysis. The results of the research led to the conclusion that the layer is the sliding plane of a huge deep-seated ancient rock slide, which we called the Sanmashan landslide. An important argument for the conclusion is the recognition of a regional compressive tectonic stress field in this area, which cannot lead to the formation of a fault graben because it needs a tensional tectonic stress field. Moreover, numerous unique geological features, sliding marks, and other relics of the ancient slide have been discovered in the field. The formation process of the ancient slide could be repeated in a large geotechnical centrifuge model test. The test shows that a deformation and failure process of "creep-crack-cut" has occurred. The type of the ancient slide can be classified as a "successive rotational rock slide". Finally, the role of seepage in the stability of the Sanmashan landslide has been analysed. Our final conclusions are that, during rainfall and filling-drawdown cycles in the Three Gorges Reservoir, the Sanmashan landslide as a whole is dormant and stable and the secondary landslides in the toe area of the slope are presently stable but can be reactivated. This

  5. Slow slip events and seismic tremor at circum-Pacific subduction zones (United States)

    Schwartz, Susan Y.; Rokosky, Juliana M.


    It has been known for a long time that slip accompanying earthquakes accounts for only a fraction of plate tectonic displacements. However, only recently has a fuller spectrum of strain release processes, including normal, slow, and silent earthquakes (or slow slip events) and continuous and episodic slip, been observed and generated by numerical simulations of the earthquake cycle. Despite a profusion of observations and modeling studies the physical mechanism of slow slip events remains elusive. The concurrence of seismic tremor with slow slip episodes in Cascadia and southwestern Japan provides insight into the process of slow slip. A perceived similarity between subduction zone and volcanic tremor has led to suggestions that slow slip involves fluid migration on or near the plate interface. Alternatively, evidence is accumulating to support the notion that tremor results from shear failure during slow slip. Global observations of the location, spatial extent, magnitude, duration, slip rate, and periodicity of these aseismic slip transients indicate significant variation that may be exploited to better understand their generation. Most slow slip events occur just downdip of the seismogenic zone, consistent with rate- and state-dependent frictional modeling that requires unstable to stable transitional properties for slow slip generation. At a few convergent margins the occurrence of slow slip events within the seismogenic zone makes it highly likely that transitions in frictional properties exist there and are the loci of slow slip nucleation. Slow slip events perturb the surrounding stress field and may either increase or relieve stress on a fault, bringing it closer to or farther from earthquake failure, respectively. This paper presents a review of slow slip events and related seismic tremor observed at plate boundaries worldwide, with a focus on circum-Pacific subduction zones. Trends in global observations of slow slip events suggest that (1) slow slip is a

  6. Spatial and Temporal Comparisons of Tremor and Slow Slip in Cascadia (United States)

    Hall, K.; Houston, H.; Schmidt, D. A.


    Tremor is often thought to be a proxy for slip during ETS events and has been shown to have a relatively abrupt updip boundary, implying an abrupt updip limit of slip. However, as shown by Houston (AGU abstract, 2012) and Hall and Houston (AGU abstract, 2014), slip inferred from GPS extended updip of the seismically-detected tremor in the 2010 M6.8 and 2012 M6.7 ETS events. If slip extending updip of tremor is a persistent phenomena, tremor cannot be directly used as a proxy for slip. Following the methods used on the 2010 and 2012 ETS event, we found that the August 2009 ETS around Portland, OR also showed slip 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 slip on the fault surface. We also compared two different inversions for 2009, one where slip was allowed on a broad regional grid and a tremor-restricted inversion (TRI) where slip was restricted to subfaults in which tremor occurred. We found the 2009 ETS event released the equivalent of a M6.8 in slip. We also found that, as in the previous ETSs, the TRI forced up to 10 cm of slip 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 slip along the updip edge in the TRI models also suggests that the geodetic data prefer slip with a larger footprint than the spatial pattern of tremor, and supports our conclusion that tremor does not represent all of the slip during an ETS event. We see consistent and clear spatial relationship between tremor and slip with some slip occurring updip of tremor. Our static inversions show where slip is

  7. Modeling of Slow Slip Events at the Hikurangi Subduction Margin (United States)

    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.


    Slow slip 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 slip 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 slip 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 slip 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 slip. 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

  8. Spacing and strength of active continental strike-slip faults (United States)

    Zuza, Andrew V.; Yin, An; Lin, Jessica; Sun, Ming


    Parallel and evenly-spaced active strike-slip faults occur widely in nature across diverse tectonic settings. Despite their common existence, the fundamental question of what controls fault spacing remains unanswered. Here we present a mechanical model for the generation of parallel strike-slip faults that relates fault spacing to the following parameters: (1) brittle-crust thickness, (2) fault strength, (3) crustal strength, and (4) crustal stress state. Scaled analogue experiments using dry sand, dry crushed walnut shells, and viscous putty were employed to test the key assumptions of our quantitative model. The physical models demonstrate that fault spacing (S) is linearly proportional to brittle-layer thickness (h), both in experiments with only brittle materials and in two-layer trials involving dry sand overlying viscous putty. The S / h slope in the two-layer sand-putty experiments may be controlled by the (1) rheological/geometric properties of the viscous layer, (2) effects of distributed basal loading caused by the viscous shear of the putty layer, and/or (3) frictional interaction at the sand-putty interface (i.e., coupling between the viscous and brittle layers). We tentatively suggest that this third effect exerts the strongest control on fault spacing in the analogue experiments. By applying our quantitative model to crustal-scale strike-slip faults using fault spacing and the seismogenic-zone thickness obtained from high-resolution earthquake-location data, we estimate absolute fault friction of active strike-slip faults in Asia and along the San Andreas fault system in California. We show that the average friction coefficient of strike-slip faults in the India-Asia collisional orogen is lower than that of faults in the San Andreas fault system. Weaker faults explain why deformation penetrates >3500 km into Asia from the Himalaya and why the interior of Asia is prone to large (M > 7.0) devastating earthquakes along major intra-continental strike-slip

  9. Modified simultaneous integrated boost radiotherapy for an unresectable huge refractory pelvic tumor diagnosed as a rectal adenocarcinoma. (United States)

    Nomiya, Takuma; Akamatsu, Hiroko; Harada, Mayumi; Ota, Ibuki; Hagiwara, Yasuhito; Ichikawa, Mayumi; Miwa, Misako; Kawashiro, Shouhei; Hagiwara, Motohisa; Chin, Masahiro; Hashizume, Eiji; Nemoto, Kenji


    A clinical trial of radiotherapy with modified simultaneous integrated boost (SIB) technique against huge tumors was conducted. A 58-year-old male patient who had a huge pelvic tumor diagnosed as a rectal adenocarcinoma due to familial adenomatous polyposis was enrolled in this trial. The total dose of 77 Gy (equivalent dose in 2 Gy/fraction) and 64.5 Gy was delivered to the center of the tumor and the surrounding area respectively, and approximately 20% dose escalation was achieved with the modified SIB technique. The tumor with an initial maximum size of 15 cm disappeared 120 d after the start of the radiotherapy. Performance status of the patient improved from 4 to 0. Radiotherapy with modified SIB may be effective for patients with a huge tumor in terms of tumor shrinkage/disappearance, improvement of QOL, and prolongation of survival.

  10. MR-based truncation and attenuation correction in integrated PET/MR hybrid imaging using HUGE with continuous table motion. (United States)

    Lindemann, Maike E; Oehmigen, Mark; Blumhagen, Jan O; Gratz, Marcel; Quick, Harald H


    The objective of this study was to introduce and evaluate a method for MR-based attenuation and truncation correction in phantom and patient measurements to improve PET quantification in PET/MR hybrid imaging. The fully MR-based method HUGE (B0 Homogenization using gradient enhancement) provides field-of-view extension in MR imaging, which can be used for truncation correction and improved PET quantification in PET/MR hybrid imaging. The HUGE method in this recent implementation is combined with continuously moving table data acquisition to provide a seamless nontruncated whole-body data set of the outer patient contours to complete the established standard MR-based Dixon-VIBE data for attenuation correction. The method was systematically evaluated in NEMA standard phantom experiments to investigate the impact of HUGE truncation correction on PET quantification. The method was then applied to 24 oncologic patients in whole-body PET/MR hybrid imaging. The impact of MR-based truncation correction with HUGE on PET data was compared to the impact of the established PET-based MLAA algorithm for contour detection. In phantom and in all patient measurements, the standard Dixon-VIBE attenuation correction data show geometric distortions and signal truncations at the edges of the MR imaging field-of-view. In contrast, the Dixon-VIBE-based attenuation correction data additionally extended by applying HUGE shows significantly less distortion and truncations and due to the continuously moving table acquisition robustly provides smooth outer contours of the patient arms. In the investigated patient cases, MLAA frequently showed an overestimation of arm volume and associated artifacts limiting contour detection. When applying HUGE, an average relative increase in SUVmean in patients' lesion of 4.2% and for MLAA of 4.6% were measured, when compared to standard Dixon-VIBE only. In specific lesions maximal differences in SUVmean up to 13% for HUGE and 14% for MLAA were measured

  11. Huge nanodielectric effects in polyimide/boron nitride nanocomposites revealed by the nanofiller size (United States)

    Diaham, S.; Saysouk, F.; Locatelli, M.-L.; Lebey, T.


    The dielectric properties of polyimide/boron nitride (PI/BN) nanocomposite films are investigated as a function of the BN nanofiller size from 20 to 350 °C and at low filler content (1-2 vol.%). The role of the BN nanofiller size on the large reduction of the electrode polarization relaxation phenomenon due to ionic movements is reported. For the two smallest BN nanoparticles (95 nm and 35 nm), the permittivity, dielectric losses and dc conductivity are strongly attenuated above 200 °C by a factor of 10 to 1000 compared to neat PI. Thus, the dc conductivity at 350 °C is reduced from 4   ×   10-8 Ω-1 cm-1 for neat PI to 3   ×   10-11 Ω-1 cm-1 for PI/BN (35 nm). Moreover, a further decrease is obtained by functionalizing the nanofiller surface with a silane coupling agent which improves the grafting of PI chains on those latter nanoparticles. These results highlight the trapping efficiency in the interphase region introduced by the small BN nanofillers (<100 nm) and provides evidence as to the huge nanodielectric effects on the charge carrier transport controlled by the nanoparticle diameter. This finding should be of great importance for advanced high temperature electrical insulation in the future.

  12. Huge thermal conductivity enhancement in boron nitride – ethylene glycol nanofluids

    Energy Technology Data Exchange (ETDEWEB)

    Żyła, Gaweł, E-mail: [Department of Physics and Medical Engineering, Rzeszow University of Technology, Rzeszow, 35-905 (Poland); Fal, Jacek; Traciak, Julian [Department of Physics and Medical Engineering, Rzeszow University of Technology, Rzeszow, 35-905 (Poland); Gizowska, Magdalena; Perkowski, Krzysztof [Department of Nanotechnology, Institute of Ceramics and Building Materials, Warsaw, 02-676 (Poland)


    Paper presents the results of experimental studies on thermophysical properties of boron nitride (BN) plate-like shaped particles in ethylene glycol (EG). Essentially, the studies were focused on the thermal conductivity of suspensions of these particles. Nanofluids were obtained with two-step method (by dispersing BN particles in ethylene glycol) and its’ thermal conductivity was analyzed at various mass concentrations, up to 20 wt. %. Thermal conductivity was measured in temperature range from 293.15 K to 338.15 K with 15 K step. The measurements of thermal conductivity of nanofluids were performed in the system based on a device using the transient line heat source method. Studies have shown that nanofluids’ thermal conductivity increases with increasing fraction of nanoparticles. The results of studies also presented that the thermal conductivity of nanofluids changes very slightly with the increase of temperature. - Highlights: • Huge thermal conductivity enhancement in BN-EG nanofluid was reported. • Thermal conductivity increase very slightly with increasing of the temperature. • Thermal conductivity increase linearly with volume concentration of particles.

  13. Synovial sarcoma presenting with huge mediastinal mass: a case report and review of literature (United States)


    Background Synovial sarcoma presenting in the mediastinum is exceedingly rare. Furthermore, data addressing optimal therapy is limited. Herein we present a case where an attempt to downsize the tumor to a resectable state with chemotherapy was employed. Case presentation A 32 year female presented with massive pericardial effusion and unresectable huge mediastinal mass. Computed axial tomography scan - guided biopsy with adjunctive immunostains and molecular studies confirmed a diagnosis of synovial sarcoma. Following three cycles of combination Ifosfamide and doxorubicin chemotherapy, no response was demonstrated. The patient refused further therapy and had progression of her disease 4 months following the last cycle. Conclusion Synovial sarcoma presenting with unresectable mediastinal mass carry a poor prognosis. Up to the best of our knowledge there are only four previous reports where primary chemotherapy was employed, unfortunately; none of these cases had subsequent complete surgical resection. Identification of the best treatment strategy for patients with unresectable disease is warranted. Our case can be of benefit to medical oncologists and thoracic surgeons who might be faced with this unique and exceedingly rare clinical scenario. PMID:23800262

  14. Unexpected Huge Dimerization Ratio in One-Dimensional Carbon Atomic Chains. (United States)

    Lin, Yung-Chang; Morishita, Shigeyuki; Koshino, Masanori; Yeh, Chao-Hui; Teng, Po-Yuan; Chiu, Po-Wen; Sawada, Hidetaka; Suenaga, Kazutomo


    Peierls theory predicted atomic distortion in one-dimensional (1D) crystal due to its intrinsic instability in 1930. Free-standing carbon atomic chains created in situ in transmission electron microscope (TEM)1-3 are an ideal example to experimentally observe the dimerization behavior of carbon atomic chain within a finite length. We report here a surprisingly huge distortion found in the free-standing carbon atomic chains at 773 K, which is 10 times larger than the value expected in the system. Such an abnormally distorted phase only dominates at the elevated temperatures, while two distinct phases, distorted and undistorted, coexist at lower or ambient temperatures. Atom-by-atom spectroscopy indeed shows considerable variations in the carbon 1s spectra at each atomic site but commonly observes a slightly downshifted π* peak, which proves its sp(1) bonding feature. These results suggest that the simple model, relaxed and straight, is not fully adequate to describe the realistic 1D structure, which is extremely sensitive to perturbations such as external force or boundary conditions.

  15. A Huge Capital Drop with Compression of Femoral Vessels Associated with Hip Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Tomoya Takasago


    Full Text Available A capital drop is a type of osteophyte at the inferomedial portion of the femoral head commonly observed in hip osteoarthritis (OA, secondary to developmental dysplasia. Capital drop itself is typically asymptomatic; however, symptoms can appear secondary to impinge against the acetabulum or to irritation of the surrounding tissues, such as nerves, vessels, and tendons. We present here a case of unilateral leg edema in a patient with hip OA, caused by a huge bone mass occurring at the inferomedial portion of the femoral head that compressed the femoral vessels. We diagnosed this bone mass as a capital drop secondary to hip OA after confirming that the mass occurred at least after the age of 63 years based on a previous X-ray. We performed early resection and total hip arthroplasty since the patient’s hip pain was due to both advanced hip OA and compression of the femoral vessels; moreover, we aimed to prevent venous thrombosis secondary to vascular compression considering the advanced age and the potent risk of thrombosis in the patient. A large capital drop should be considered as a cause of vascular compression in cases of unilateral leg edema in OA patients.

  16. Acute abdomen in early pregnancy caused by torsion of bilateral huge multiloculated ovarian cysts

    Directory of Open Access Journals (Sweden)

    Sathiyakala Rajendran


    Full Text Available The association of pregnancy and torsion of bilateral huge benign ovarian cyst is rare. We report a case of multigravida at 13 weeks of pregnancy presenting with acute onset of lower abdominal pain. Ultrasound revealed bilateral multiloculated ovarian cysts of size 10x10 cm on right side and 15x10cm on left side with evidence of torsion and a single live intrauterine fetus of gestational age 13 weeks 4 days. Emergency laparotomy was done with vaginal susten 200 mg as perioperative tocolysis. Intra operatively, uterus was enlarged to 14 weeks size. Both ovaries were replaced with multiloculated cysts of size 15x10 cm on left side and 10x10 cm on right side. Ovarian pedicle was found to be twisted once on right side and twice on left side. On right side, untwisting of pedicle was done and the ovarian cyst was punctured at multiple sites to drain the clear fluid. Biopsy was taken from the right ovarian cyst wall. On left side, ovariotomy was done. Histopathology revealed mucinous cyst adenoma of left ovary and multiple corpus luteum in right ovarian biopsy specimen. The patient was followed up with regular antenatal check-ups and ultrasound to rule out the recurrence of ovarian cyst on right side. The patient successfully delivered a term male baby at 39 weeks. [Int J Reprod Contracept Obstet Gynecol 2015; 4(5.000: 1598-1601

  17. Propranolol in Treatment of Huge and Complicated Infantile Hemangiomas in Egyptian Children

    Directory of Open Access Journals (Sweden)

    Basheir A. Hassan


    Full Text Available Background. Infantile hemangiomas (IHs are the most common benign tumours of infancy. Propranolol has recently been reported to be a highly effective treatment for IHs. This study aimed to evaluate the efficacy and side effects of propranolol for treatment of complicated cases of IHs. Patients and Methods. This prospective clinical study included 30 children with huge or complicated IHs; their ages ranged from 2 months to 1 year. They were treated by oral propranolol. Treatment outcomes were clinically evaluated. Results. Superficial cutaneous hemangiomas began to respond to propranolol therapy within one to two weeks after the onset of treatment. The mean treatment period that was needed for the occurrence of complete resolution was 9.4 months. Treatment with propranolol was well tolerated and had few side effects. No rebound growth of the tumors was noted when propranolol dosing stopped except in one case. Conclusion. Propranolol is a promising treatment for IHs without obvious side effects. However, further studies with longer follow-up periods are needed.

  18. Computational AstroStatistics Fast and Efficient Tools for Analysing Huge Astronomical Data Sources

    CERN Document Server

    Nichol, R C; Connolly, A J; Davies, S; Genovese, C; Hopkins, A M; Miller, C J; Moore, A W; Pelleg, D; Richards, G T; Schneider, J; Szapudi, I; Wasserman, L H


    I present here a review of past and present multi-disciplinary research of the Pittsburgh Computational AstroStatistics (PiCA) group. This group is dedicated to developing fast and efficient statistical algorithms for analysing huge astronomical data sources. I begin with a short review of multi-resolutional kd-trees which are the building blocks for many of our algorithms. For example, quick range queries and fast n-point correlation functions. I will present new results from the use of Mixture Models (Connolly et al. 2000) in density estimation of multi-color data from the Sloan Digital Sky Survey (SDSS). Specifically, the selection of quasars and the automated identification of X-ray sources. I will also present a brief overview of the False Discovery Rate (FDR) procedure (Miller et al. 2001a) and show how it has been used in the detection of ``Baryon Wiggles'' in the local galaxy power spectrum and source identification in radio data. Finally, I will look forward to new research on an automated Bayes Netw...

  19. Distributed data organization and parallel data retrieval methods for huge laser scanner point clouds (United States)

    Hongchao, Ma; Wang, Zongyue


    This paper proposes a novel method for distributed data organization and parallel data retrieval from huge volume point clouds generated by airborne Light Detection and Ranging (LiDAR) technology under a cluster computing environment, in order to allow fast analysis, processing, and visualization of the point clouds within a given area. The proposed method is suitable for both grid and quadtree data structures. As for distribution strategy, cross distribution of the dataset would be more efficient than serial distribution in terms of non-redundant datasets, since a dataset is more uniformly distributed in the former arrangement. However, redundant datasets are necessary in order to meet the frequent need of input and output operations in multi-client scenarios: the first copy would be distributed by a cross distribution strategy while the second (and later) would be distributed by an iterated exchanging distribution strategy. Such a distribution strategy would distribute datasets more uniformly to each data server. In data retrieval, a greedy algorithm is used to allocate the query task to a data server, where the computing load is lightest if the data block needing to be retrieved is stored among multiple data servers. Experiments show that the method proposed in this paper can satisfy the demands of frequent and fast data query.

  20. An Automatic Cycle-Slip Processing Method and Its Precision Analysis

    Institute of Scientific and Technical Information of China (English)

    ZHENG Zuoya; LU Xiushan


    On the basis of analyzing and researching the current algorithms of cycle-slip detection and correction, a new method of cycle-slip detection and correction is put forward in this paper, that is, a reasonable cycle-slip detection condition and algorithm with corresponding program COMPRE (COMpass PRE-processing) to detect and correct cycle-slip automatically, compared with GIPSY and GAMIT software, for example, it is proved that this method is effective and credible to cycle-slip detection and correction in GPS data pre-processing.

  1. Numerical study of the effect of Navier slip on the driven cavity flow

    KAUST Repository

    He, Qiaolin


    We study the driven cavity flow using the Navier slip boundary condition. Our results have shown that the Navier slip boundary condition removes the corner singularity induced by the no-slip boundary condition. In the low Reynolds number case, the behavior of the tangential stress is examined and the results are compared with the analytic results obtained in [14]. For the high Reynolds number, we study the effect of the slip on the critical Reynolds number for Hopf bifurcation. Our results show that the first Hopf bifurcation critical Reynolds number is increasing with slip length. © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


    Institute of Scientific and Technical Information of China (English)

    Ding Wenjing; Fan Shichao; Lu Mingwan


    This paper, using Karnopp's model of friction force and phase plane method, studies the stick-slip motion of the flexible drive mechanism. It is explained that a sudden drop of friction force is the essential source of stick-slip motion when the sliding is impending. A new criterion for occurrence of stick-slip motion is established.The stick-slip region and the stable region in a parameter plane are separated by a critical parameter curve. Moreover, for the stick-slip motion of the flexible drive mechanism without viscous damping, a parameter expression is obtained. The results may be used in design of the flexible drive mechanism.

  3. Water generation and transport below Europa's strike-slip faults (United States)

    Kalousová, Klára; Souček, Ondřej; Tobie, Gabriel; Choblet, Gaël.; Čadek, Ondřej


    Jupiter's moon Europa has a very young surface with the abundance of unique terrains that indicate recent endogenic activity. Morphological models as well as spectral observations suggest that it might possess shallow lenses of liquid water within its outer ice shell. Here we investigate the generation and possible accumulation of liquid water below the tidally activated strike-slip faults using a numerical model of two-phase ice-water mixture in two-dimensional Cartesian geometry. Our results suggest that generation of shallow partially molten regions underneath Europa's active strike-slip faults is possible, but their lifetime is constrained by the formation of Rayleigh-Taylor instabilities due to the negative buoyancy of the melt. Once formed, typically within a few million years, these instabilities efficiently transport the meltwater through the shell. Consequently, the maximum water content in the partially molten regions never exceeds 10% which challenges their possible detection by future exploration mission.

  4. Slip-stick excitation and travelling waves excite silo honking (United States)

    Vriend, Nathalie; Warburton, Kasia; Porte, Elze


    Industrial storage silos filled with PET-particles can create a sound upon discharge. The sound forms a nuisance for the environment when the structure starts to act as a loudspeaker and may ultimately result in structural failure. This work investigates the phenomenon experimentally-the deployment of a microphone, an accelerometer and high-speed imaging on a laboratory set-up reveal the driving mechanism for the structural resonance: stick-slip at the wall. Particle image velocimetry shows an asymmetric, upwards travelling wave (at 50 m/s) which contains the dynamic "slip"-region. The frequency of the mechanical motion of the grains is successfully correlated to the frequency of the emitted sound. Friction models are explored to describe and quantify the frictional interaction between the grains and the wall.


    Directory of Open Access Journals (Sweden)



    Full Text Available The purpose of this study is to synthesize nano-grained Calcium Hydroxyapatite (HAp through slip casting technique. For this, hydroxyapatite powders were synthesized using two methods, wet chemical method and Ammoniacal method. The as-prepared powders and calcined powders were characterized using XRD, FTIR, to study the phases of the powders. The hydroxyapatite powder calcined at 1000°C for 2hr was used to prepare 50 vol% slurry using DN40 (sodium olyacrylate as dispersing agent. After slip casting, the green bodies were sintered at different temperatures, 1100, 1200, 1250 and 1300°C with 2hr soaking time. The sintered dense samples were characterized for physical and mechanical behavior.Dense HaP samples were obtained at 1250C.

  6. Soft matter dynamics: Accelerated fluid squeeze-out during slip (United States)

    Hutt, W.; Persson, B. N. J.


    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 slip it is very rapidly removed resulting (for the grease lubricated surface) in complete stop of motion after a short time period, corresponding to a slip 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.

  7. Cytoplasmic streaming in plant cells: the role of wall slip. (United States)

    Wolff, K; Marenduzzo, D; Cates, M E


    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 slip layer. By using realistic parameter values for actin lane and myosin density, as well as for endoplasmic and vacuole viscosity and the slip 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.

  8. Slipped capital femoral epiphysis caused by neurogenic heterotopic ossification. (United States)

    Chang, Sam Yeol; Yoo, Won Joon; Park, Moon Seok; Chung, Chin Youb; Choi, In Ho; Cho, Tae-Joon


    Slipped capital femoral epiphysis (SCFE) is rare in nonambulatory patients, as mechanical factors play important roles in the development of the disease. We report a case of SCFE, which occurred in a 12-year-old girl with a nonambulatory status after cerebral infarction. SCFE occurred after she received passive range of motion exercise and extracorporeal shock wave treatment for neurogenic heterotopic ossification around the hip joint. The patient was successfully managed by a stepwise approach, with radiological and clinical improvements.

  9. Implications of Fault Curvature for Slip Distributions, Opening, and Damage (United States)

    Ritz, E.; Pollard, D. D.; Griffith, W. A.


    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-slip faults in the Bear Creek drainage, Sierra Nevada, CA, provide insights into the relationship between non-planar fault geometry and frictional slip 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 slip 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 slip 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.

  10. Weakly nonlinear stability of ultra-thin slipping films

    Institute of Scientific and Technical Information of China (English)

    HU Guohui


    A weakly nonlinear theory is presented to study the effects of slippage on the stability of the ultra-thin polymer films.The nonlinear mathematical model is constructed for perturbations of small finite amplitude based on hydrodynamic equations with the long wave approximation. Results reveal that the nonlinearity always accelerates the rupture of the films. The influences of the slip length, film thickness, and initial amplitude of perturbations on the rupture of the films are investigated.

  11. Research Development and Perspective on Slow Slip, Tremors, and Slow Earthquakes

    Institute of Scientific and Technical Information of China (English)

    Wang Yanzhao; Shen Zhengkang


    Seismological and geodetic observations indicate that slow slip sometimes occurs in active fault zones beneath the seismogenic depth, and large slow slip can result in transient ground motion.Slow earthquakes, on the other hand, emit tremor-like signals within a narrow frequency band, and usually produce no catastrophic consequences. In general, slow slip and slow earthquakes probably correspond to deformation processes associated with releasing elastic energy in fault zones, and understanding their mechanisms may help improve our understanding of fault zone dynamic processes. This article reviews the research progress on slow slip and slow earthquakes over the last decade. Crustal motion and tremor activities associated with slow slip and slow earthquakes have been investigated extensively, mainly involving locating sources of slow slip and slow earthquakes and numerical modeling of their processes. In the meantime, debates have continued about slow slip and slow earthquakes,such as their origins, relationship, and mechanisms.

  12. Hydrodynamics beyond Navier-Stokes: the slip flow model. (United States)

    Yudistiawan, Wahyu P; Ansumali, Santosh; Karlin, Iliya V


    Recently, analytical solutions for the nonlinear Couette flow demonstrated the relevance of the lattice Boltzmann (LB) models to hydrodynamics beyond the continuum limit [S. Ansumali, Phys. Rev. Lett. 98, 124502 (2007)]. In this paper, we present a systematic study of the simplest LB kinetic equation-the nine-bit model in two dimensions--in order to quantify it as a slip flow approximation. Details of the aforementioned analytical solution are presented, and results are extended to include a general shear- and force-driven unidirectional flow in confined geometry. Exact solutions for the velocity, as well as for pertinent higher-order moments of the distribution functions, are obtained in both Couette and Poiseuille steady-state flows for all values of rarefaction parameter (Knudsen number). Results are compared with the slip flow solution by Cercignani, and a good quantitative agreement is found for both flow situations. Thus, the standard nine-bit LB model is characterized as a valid and self-consistent slip flow model for simulations beyond the Navier-Stokes approximation.

  13. Enhanced Dynamical Stability with Harmonic Slip-stacking

    CERN Document Server

    Eldred, Jeffrey


    We develop a configuration of radio-frequency (rf) cavities to dramatically improve the performance of slip-stacking. Slip-stacking is an accumulation technique used at Fermilab to nearly double proton intensity by maintaining two beams of different momenta in the same storage ring. The two particle beams are longitudinally focused in the Recycler 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. We show the harmonic rf cavity cancels out the resonances generated between the two main rf cavities and we derive the relationship between the harmonic rf voltage and the main rf voltage. We find the area factors that can be used to calculate the available phase space area for any set of beam parameters without individual simulation. We establish Booster beam quality requirements to achieve 99\\% slip-stacking efficiency. We measure the longitudinal dis...

  14. Surface Slip Gradients and Fault Connectivity at Depth (United States)

    Oglesby, D. D.


    Observational and numerical evidence has implied that it is difficult for earthquake rupture to jump stepovers with widths significantly larger than 4 km [e.g., Harris et al., 1991; Harris and Day, 1999; Wesnousky, 2006]. It has also been shown observationally that if surface slip tapers to zero over a small along-strike distance on the primary fault segment at a stepover, an earthquake has a significantly increased likelihood of jumping the stepover and propagating to a secondary fault segment [Elliott et al., 2009]. This latter result has been attributed to a high slip gradient on the primary segment generating a strong dynamic stress concentration on the second segment, which can facilitate rupture renucleation [Oglesby, 2008]. Recent 3D dynamic earthquake simulations, however, provide an alternative interpretation for this effect: an earthquake on a fault that is disconnected at the surface but is connected (i.e., is a throughgoing structure) at depth also will tend to produce a higher surface slip gradient at the edges of the segments than will a system that is fully disconnected, at least for relatively long segments that are connected at relatively shallow depth. This result raises the possibility that many of the rupture "jumps" that we see at fault stepovers on the surface may in fact reflect through-going ruptures on a continuous subsurface fault. These results may have implications for the pervasiveness of fault connectivity at depth, the likelihood of throughgoing rupture at surface stepovers, ground motion estimates, and seismic hazard.

  15. Slip Flow in Elliptic Microducts with Constant Heat Flux

    Directory of Open Access Journals (Sweden)

    Marco Spiga


    Full Text Available This paper outlines a numerical model for determining the dynamic and thermal performances of a rarefied fluid flowing in a microduct with elliptical cross-section. A slip flow is considered, in laminar steady state condition, in fully developed forced convection, with Knudsen number in the range 0.001−0.1, in H1 boundary conditions. The velocity and temperature distributions are determined in the elliptic cross-section, for different values of both aspect ratio γ and Knudsen number, resorting to the Comsol Multiphysics software, to solve the momentum and energy equations. The friction factors (or Poiseuille numbers and the convective heat transfer coefficients (or Nusselt numbers are calculated and presented in graphs and tables. The numerical solution is validated resorting to data available in literature for continuum flow in elliptic cross-sections (Kn = 0 and for slip flow in circular ducts (γ=1. A further benchmark is carried out for the velocity profile for slip flow in ellipticalcross-sections, thanks to a recent analytical solution obtained using elliptic cylinder coordinates and the separation of variables method. The Poiseuille and Nusselt numbers for elliptic cross-sections are discussed. The results may be used to predict pressure drop and heat transfer performance in metallic microducts with elliptic cross-section, produced by microfabrication for microelectromechanical systems (MEMS.

  16. Onset of aseismic creep on major strike-slip faults

    KAUST Repository

    Çakir, Ziyadin


    Time series analysis of spaceborne synthetic aperture radar (SAR) data, GPS measurements, and fi eld observations reveal that the central section of the Izmit (Turkey) fault that slipped with a supershear rupture velocity in the A.D. 1999, Mw7.4, Izmit earthquake began creeping aseismically following the earthquake. Rapid initial postseismic afterslip decayed logarithmically with time and appears to have reached a steady rate comparable to the preearthquake full fault-crossing rate, suggesting that it may continue for decades and possibly until late in the earthquake cycle. If confi rmed by future monitoring, these observations identify postseismic afterslip as a mechanism for initiating creep behavior along strike-slip faults. Long-term afterslip and/or creep has signifi cant implications for earthquake cycle models, recurrence intervals of large earthquakes, and accordingly, seismic hazard estimation along mature strike-slip faults, in particular for Istanbul which is believed to lie adjacent to a seismic gap along the North Anatolian fault in the Sea of Marmara. © 2012 Geological Society of America.

  17. Residual hip growth after pinning of slipped capital femoral epiphysis. (United States)

    Breaud, Jean; Rubio, Amandine; Leroux, Julien; Griffet, Jacques


    Screwing of slipped capital femoral epiphysis must prevent its further slipping by prematurely fusing the physis. Whichever material is used, persistent femoral growth has been described, thereby increasing the risk of bone deformation. The objective of this study is to evaluate the residual growth after screwing of slipped capital femoral epiphysis. This study concerned 26 children, among which 13 children have been included, and 13 children excluded because of an incomplete clinical or radiological follow-up, or treatment by another technique. The pathological hip was treated with one screw (in eight cases) or two screws (in five cases). The controlateral hip was fixed with one screw. The different measures were taken on anteroposterior radiographs done the days after surgery, and on the first radiograph on which the growth plate had fused. Growth plate fusion was obtained after an average of 20 months. Each patient had presented a residual growth of at least one hip, thus 85% of the 26 fixed screws. Among the four hips, which did not grow, three were pathological, and were fixed by one screw (in one case) or two screws (in two cases), in a central or medial position. There was not any statistical relationship between the growth persistence and the other studied criteria. These results, proving the growth persistency, suggest that the follow-up must be extremely careful, as the number of threads crossing the growth plate will decrease, with the risk of loss of mechanical stability and reappearance of the femoral epiphysis slippage.

  18. Water slip flow in superhydrophobic microtubes within laminar flow region

    Institute of Scientific and Technical Information of China (English)

    Zhijia Yu; Xinghua Liu; Guozhu Kuang


    The fabrication of superhydrophobic surfaces and the studies on water flow characteristics therein are of great significance to many industrial areas as wel as to science and technology development. Experiments were car-ried out to investigate slip characteristics of water flowing in circular superhydrophobic microtubes within lam-inar flow region. The superhydrophobic microtubes of stainless steel were fabricated with chemical etching–fluorination treatment. An experimental setup was designed to measure the pressure drop as function of water flow rate. For comparison, superhydrophilic tubes were also tested. Poiseuille number Po was found to be smaller for the superhydrophobic microtubes than that for superhydrophilic ones. The pressure drop reduc-tion ranges from 8%to 31%. It decreases with increasing Reynolds number when Re b 900, owing to the transition from Cassie state to Wenzel state. However, it is almost unchanged with further increasing Re after Re N 900. The slip length in superhydrophobic microtubes also exhibits a Reynolds number dependence similarly to the pressure drop reduction. The relation between slip length and Darcy friction factor is theoretically analyzed with consideration of surface roughness effect, which was testified with the experimental results.

  19. Stick-slip advance of the Kohat Plateau in Pakistan (United States)

    Satyabala, S. P.; Yang, Zhaohui; Bilham, Roger


    Throughout most of the Himalaya, slip of the Indian Plate is restrained by friction on the interface between the plate and the overlying wedge of Himalayan rocks. Every few hundred years, this interface--or décollement--ruptures in one or more Mw >=8 earthquakes. In contrast, in the westernmost Himalaya, the Indian Plate slips aseismically beneath wide plateaux fronting the Kohistan Mountains. The plateaux are underlain by viscous décollements that are unable to sustain large earthquakes. Potwar, the widest of these plateaux is underlain by viscous salt, which currently permits it to slide at rates of about 3mmyr-1 (refs , ), much slower than its 2 Myr average. This deceleration has been attributed to recently increased friction through the loss of salt from its décollement. Here we use interferometric synthetic aperture radar and seismic data to assess movement of the Kohat Plateau--the narrowest and thickest plateau. We find that in 1992 an 80 km2 patch of the décollement ruptured in a rare Mw 6.0 earthquake, suggesting that parts of the décollement are locally grounded. We conclude that this hybrid seismic and aseismic behaviour represents an evolution of the mode of slip of the plateaux from steady creep towards increasingly widespread seismic rupture.

  20. Surface slip associated with the 2004 Parkfield, California, earthquake measured on alinement arrays (United States)

    Lienkaemper, J.J.; Baker, B.; McFarland, F.S.


    Although still continuing, surface slip 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 slip along the main trace and the Southwest Fracture Zone (SWFZ). Slip here was higher in 1966 at about 40 cm. The distribution of 2004 slip appears to have a shape similar to that of the 1966 event, but final slip is expected to be lower in 2004 by about 3-15 cm, even when continuing slip is accounted for. Proportionately, this difference is most notable at the south end at Highway 46, where the 1966 event slip was 13 cm compared to the 2004 slip of 4 cm. Continuous Global Positioning System and creepmeters suggest that significant surface coseismic slip 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 slip occurred on the main trace between Parkfield and Gold Hill. We infer that 3-6 cm slip accumulated across our arrays in the first 24 hr. At Highway 46, slip 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 slip per event may suggest that larger slip deficits are now growing along the Parkfield segment.

  1. Episodic tremor and slip in Northern Sumatra subduction zone (United States)

    Sianipar, Dimas; Subakti, Hendri


    The first reported observation of non-volcanic tremor in Sunda Arc in Sumbawa, Indonesia open a possibility of discovery of episodic tremor and slip (ETS) from out of Pacific Rim. Non-volcanic tremor gives some important information about dynamic of plate boundaries. The characteristics of these tremors are visually as non-impulsive, high frequency, long-duration and low-amplitude signals. Tectonic tremor occurred in a transition part of brittle-ductile of a fault and frequently associated with the shearing mechanism of slow slip. Tectonic tremor is a seismic case that also very interested, because it shows strong sensitivity to stress changes. Deep non-volcanic tremor is usually associated with episodic slow-slip events. Tectonic tremor is found in close association with geodetically observed slow-slip events (SSE) in subduction zones. One research found that there is possibility of SSE occurrence on Banyak Islands, North Sumatra revealed from coral observation. The SSE occurred on the Banyak Islands portion of the megathrust at 30-55 km depth, within the downdip transition zone. We do a systematic search of episodic tremor and its possible relationship with slow-slip phenomena in Northern Sumatra subduction zone. The spectrogram analysis is done to analyze the potential tremor signals. We use three component broadband seismic stations with 20, 25, and 50 sampling per second (BH* and SH* channels). We apply a butterworth 5 Hz highpass filter to separate the signal as local tremor and teleseismic/regional earthquakes. Before computing spectrogram to avoid high-frequency artifacts to remote triggering, we apply a 0.5 Hz filter. We also convert the binary seismic data into sound waves to make sure that these events meet the tectonic tremor criterion. We successfully examine 3 seismic stations with good recording i.e. GSI, SNSI and KCSI. We find there are many evidences of high frequency episodic tremor like signals. This include an analysis of potential triggered

  2. The Slumgullion Natural Laboratory for Observing Slip Phenomena (United States)

    Gomberg, J. S.; Schulz, W. H.; Bodin, P.; Kean, J. W.; Wang, G.; Coe, J. A.; MacQueen, P.; Foster, K.; Creager, K.


    Many natural systems release stresses by failure and sliding across surfaces; examples include landslides, glaciers, crustal- and plate-scale faults. Observational advances continue to reveal diversity in the seismic signals associated with fault slip and how such stress relaxation can occur, even on a single fault system. A particularly rich example are the episodes of slow fault slip near major subduction and transform plate boundaries that manifest as geodetically observed aseismic deformation abetted by a family of seismic signals depleted in high-frequencies relative to those from earthquakes (named ‘episodic tremor and slip’ or ETS). While the driving forces and scales differ, there are striking parallels between some observations and models of ETS and of landslide behaviors; e.g. in both, postulated key controls include rate-dependent friction and strength modulated by pore-pressure changes, dilatancy during rapid shear, and subsequent consolidation. To explore common features and the underlying processes we are studying the Slumgullion landslide, an ideal natural laboratory for observing fault slip and associated seismic and aseismic phenomena. Unlike crustal- or plate-scale studies significant deformation can be measured within a single field season, because the Slumgullion moves at average rates of cm/day. Moreover, pore pressures, displacements, material properties, and environmental variables may be measured directly and continuously at several locations on the landslide (albeit not at the basal sliding surface). We have just completed a field experiment on the Slumgullion to test several hypotheses, particularly that slip along the basal surface and side-bounding faults occurs with comparable richness of aseismic and seismic modes as crustal- and plate-scale boundaries. To do so from August 18-26, 2009 we continuously monitored the displacement-field using a robotic electronic displacement meter and the seismic radiation with 88 vertical

  3. Endovascular Treatment of the Huge Dissecting Aneurysms Involving the Basilar Artery by the Internal Trapping Technique: Technical Note

    Directory of Open Access Journals (Sweden)

    Shi-Qing Mu


    Full Text Available Background: The endovascular strategy of the huge dissecting aneurysms involving the basilar artery (BA is controversial and challenging. This study was to investigate the clinical and angiographic outcomes of the treatment of the huge dissecting aneurysms involving the BA by the internal trapping (IT technique. Methods: We retrospectively studied 15 patients with the huge dissecting aneurysms involving the BA treated by the IT technique between September 2005 and September 2014 in Department of Interventional Neuroradiology of Beijing Tiantan Hospital. Clinical and angiographic data were reviewed and evaluated. Results: All patients were treated by the IT technique. That meant the dissecting artery and aneurysm segments were completed occlusion. After the procedure, the angiography demonstrated that all the dissecting artery and aneurysm segments were completed occlusion. Follow-up angiography was performed at 3-6 months or 12-18 months after the endovascular treatment (median 8 months, 14 patients had a good recovery. Re-canalization occurred in one patient whose aneurysm involved in bilateral vertebral arteries and the two third of the middle-lower BA. After the second treatment, the patient died by the ventricular tachycardia. Conclusions: The IT technique is a technically feasible and safe alternative for the treatment of BA dissecting aneurysms, but it is not necessarily the safest or most definitive treatment modality. The ideal treatment of the huge dissecting aneurysms involving the BA remains debatable and must be investigated on a case-by-case basis.

  4. Endovascular Treatment of the Huge Dissecting Aneurysms Involving the Basilar Artery by the Internal Trapping Technique: Technical Note

    Institute of Scientific and Technical Information of China (English)

    Shi-Qing Mu; Xin-Jian Yang; You-Xiang Li; Chu-Han Jiang; Zhong-Xue Wu


    Background:The endovascular strategy of the huge dissecting aneurysms involving the basilar artery (BA) is controversial and challenging.This study was to investigate the clinical and angiographic outcomes of the treatment of the huge dissecting aneurysms involving the BA by the internal trapping (IT) technique.Methods:We retrospectively studied 15 patients with the huge dissecting aneurysms involving the BA treated by the IT technique between September 2005 and September 2014 in Department of lnterventional Neuroradiology of Beijing Tiantan Hospital.Clinical and angiographic data were reviewed and evaluated.Results:All patients were treated by the IT technique.That meant the dissecting artery and aneurysm segments were completed occlusion.After the procedure,the angiography demonstrated that all the dissecting artery and aneurysm segments were completed occlusion.Follow-up angiography was performed at 3-6 months or 12-18 months after the endovascular treatment (median 8 months),14 patients had a good recovery.Re-canalization occurred in one patient whose aneurysm involved in bilateral vertebral arteries and the two third of the middle-lower BA.After the second treatment,the patient died by the ventricular tachycardia.Conclusions:The IT technique is a technically feasible and safe alternative for the treatment of BA dissecting aneurysms,but it is not necessarily the safest or most definitive treatment modality.The ideal treatment of the huge dissecting aneurysms involving the BA remains debatable and must be investigated on a case-by-case basis.

  5. Treating Huge Tear-Drop Fracture of Axis With Trapezoidal Bone: A Case Report and Literature Review. (United States)

    Yang, Xiaobin; Zheng, Bolong; Hao, Dingjun; Liu, Benyin; Yan, Liang; He, Baorong


    Case report and review of relevant literature. To discuss the surgical strategies and clinical outcome of managing huge tear drop fracture of axis. Teardrop fracture of axis is rarely seen, especially the huge type. The surgical technique is demanding because of the special anatomical structure and difficulty with bone grafting. Moreover, the surgical approach is controversial in the literature. A 51-year-old male patient suffered from neck pain after falling from the bicycle, neck movement was limited with no neurological compromise. X-ray suggested huge tear-drop fracture of anterior-inferior corner of axis, narrowing of C2/3 intervertebral disc. Fusion with self-designed tricortical trapezoidal iliac bone was performed. Treating huge teardrop fracture of axis by anterior bone grafting with self-designed tricortical trapezoidal iliac bone is effective and stable. A 3-month follow-up showed fusion was achieved, upper cervical curvature was restored, and neck pain disappeared. Self-designed tricortical trapezoidal iliac bone provided adequate fusion area of bone grafting, restoring the normal intervertebral height and cervical alignment, and the midterm outcome is satisfactory. 5.

  6. Huge pseudomyxoma peritonei: Surgical strategies and procedures to employ to optimize the rate of complete cytoreductive surgery. (United States)

    Benhaim, L; Honoré, C; Goéré, D; Delhorme, J-B; Elias, D


    Complete cytoreductive surgery (CCRS) plus Hyperthermic Intraperitoneal Chemotherapy (HIPEC) is the best-known treatment for pseudomyxoma peritonei (PMP). In 30% of the cases, PMP realize a widespread involvement of the peritoneal cavity. In these extreme situations, we developed, devoted strategies to optimize the feasibility and safety of CCRS. This study describes the surgical resections required for CCRS and the consequent approaches that we propose to achieve CCRS. We defined "huge PMP" by a peritoneal cancer index (PCI) ≥ 28. Surgical procedures of patients operated on between 1994 and 2014 were retrospectively reviewed from a prospective database in a single institution. During this period, 311 patients were operated on and 247 (79%) underwent CCRS + HIPEC. Among them, 100 patients presented "huge" PMP and 54 patients underwent CCRS + HIPEC. In patients with "huge" PMP, the rate of CCRS + HIPEC was 25% before 2002 and reached 71% between 2011 and 2014. We identified 3 conditions for CCRS 1) to guaranty a sufficient length of residual small bowel 2) to preserve the left gastric vessels in order to preserve the superior third of the stomach 3) to ensure that the hepatic pedicle can be entirely cleared from its tumor involvement. None of the other peritonectomy procedures were decisional for CCRS. Our learning curve improved the selection and completion rate of CCRS + HIPEC for "huge PMP". Some anatomical and physiological prerequisites guarantee the feasibility and safety of such extensive surgeries. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Endovascular Treatment of the Huge Dissecting Aneurysms Involving the Basilar Artery by the Internal Trapping Technique: Technical Note. (United States)

    Mu, Shi-Qing; Yang, Xin-Jian; Li, You-Xiang; Jiang, Chu-Han; Wu, Zhong-Xue


    The endovascular strategy of the huge dissecting aneurysms involving the basilar artery (BA) is controversial and challenging. This study was to investigate the clinical and angiographic outcomes of the treatment of the huge dissecting aneurysms involving the BA by the internal trapping (IT) technique. We retrospectively studied 15 patients with the huge dissecting aneurysms involving the BA treated by the IT technique between September 2005 and September 2014 in Department of Interventional Neuroradiology of Beijing Tiantan Hospital. Clinical and angiographic data were reviewed and evaluated. All patients were treated by the IT technique. That meant the dissecting artery and aneurysm segments were completed occlusion. After the procedure, the angiography demonstrated that all the dissecting artery and aneurysm segments were completed occlusion. Follow-up angiography was performed at 3-6 months or 12-18 months after the endovascular treatment (median 8 months), 14 patients had a good recovery. Re-canalization occurred in one patient whose aneurysm involved in bilateral vertebral arteries and the two third of the middle-lower BA. After the second treatment, the patient died by the ventricular tachycardia. The IT technique is a technically feasible and safe alternative for the treatment of BA dissecting aneurysms, but it is not necessarily the safest or most definitive treatment modality. The ideal treatment of the huge dissecting aneurysms involving the BA remains debatable and must be investigated on a case-by-case basis.

  8. Is hepatectomy for huge hepatocellular carcinoma (≥ 10 cm in diameter) safe and effective? A single-center experience. (United States)

    Yang, Jian; Li, Chuan; Wen, Tian-Fu; Yan, Lu-Nan; Li, Bo; Wang, Wen-Tao; Yang, Jia-Yin; Xu, Ming-Qing


    This retrospective study aimed to validate the safety and effectiveness of hepatectomy for huge hepatocellular carcinoma (HCC). Data of patients who underwent hepatectomy for HCC between January 2006 and December 2012 were reviewed. The patients were divided into three groups: huge HCC(≥ 10 cm in diameter), large HCC(≥ 5 buthuge and large HCC groups were lower than that of the small HCC group (OS: 32.5% vs 36.3% vs 71.2%, p=0.000; DFS: 20.0% vs 24.8% vs 40.7%, p=0.039), but there was no difference between the huge and large HCC groups (OS: 32.5% vs 36.3%, p=0.667; DFS: 20.0% vs 24.8%, p=0.540). In multivariate analysis, five independent poor prognostic factors that affected OS were significantly associated with worse survival (phuge HCC is similar to that for large and small HCC; and this approach for huge HCC may achieve similar long-term survival and disease-free survival as for large HCC.

  9. Flume tests to study the initiation of huge debris flows after the Wenchuan earthquake in S-WChina

    NARCIS (Netherlands)

    Hu, Wei; Xu, Qiang; van Asch, Theo.W.J.; Zhua, X; Xu, Q.Q.


    In the Wenchuan area in the southwest of China, a huge amount of loose co-seismic landslide material was deposited on slopes during the Wenchuan earthquake of May 2008. These loose deposits formed the source material for rainfall-induced debris flows or shallow landslides in the years after the eart

  10. Extreme multi-millennial slip rate variations on the Garlock fault, California: geomorphology and geochronology of slip rate constraints (United States)

    Rhodes, Edward; Dolan, James; McGill, Sally; McAuliffe, Lee; Zinke, Robert


    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 slip rate during the Holocene for this left-lateral strike-slip 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 slip 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.

  11. Clinicopathological profile, airway management, and outcome in huge multinodular goiters: an institutional experience from an endemic goiter region. (United States)

    Agarwal, Amit; Agarwal, Sudhi; Tewari, Prabhat; Gupta, Sushil; Chand, Gyan; Mishra, Anjali; Agarwal, Gaurav; Verma, A K; Mishra, S K


    Huge goiters are common in iodine-deficient endemic regions. They are of concern to the surgeons because of the anticipated risk of difficult dissection and increased chances of surgical complications. Similarly, they are of concern to the anesthesiologists because of anticipated intubation-related difficulties and post-thyroidectomy tracheomalacia. In the present study we aimed to present our experience of managing goiters based on their gross weight, highlighting their clinicopathological profile, perioperative airway-related difficulties, and management of surgical morbidity. Retrospective analysis of patients who underwent total thyroidectomy in the primary setting at our institute from 1995 to 2009 was carried out based on the gross gland weight. The patients were thus grouped into group A: ≤200 g; group B: 201 to ≤400 g; group C: 401 to ≤600 g; group D: >600 g. Group A (660 cases); group B (108 cases); group C (36 cases); and group D (9 cases) were included. As the goiter size increased, the mean duration of goiter, compressive symptoms, retrosternal extension (RSE), airway deformity, intubation difficulty, and tracheomalacia increased. The rate of tracheostomy, sternotomy, hemorrhage, visceral injury, and hospital stay was high with huge goiters. These features were more marked in malignant goiters compared to benign goiters. However, the postoperative complications were comparable in both of those groups. Long-standing huge goiters are common in iodine-deficient endemic areas. The majority of patients have symptomatic or clinicoradiological evidence of airway involvement. The incidence of RSE, airway deformity, intubation difficulty, and tracheomalacia is high with huge goiters. The surgery is technically demanding with greater associated chances of injury to native structures. Malignancy influences the presentation and outcome in smaller goiters. In centers with experienced endocrine surgeons and dedicated anesthetists, huge goiters can be

  12. Fault slip and earthquake recurrence along strike-slip faults — Contributions of high-resolution geomorphic data

    KAUST Repository

    Zielke, Olaf


    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 slip-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 slip distributions and along-fault slip 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 slip-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

  13. Modeling stick-slip-separation dynamics in a bimodal standing wave ultrasonic motor (United States)

    Li, Xiang; Yao, Zhiyuan; Lv, Qibao; Liu, Zhen


    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-slip 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-slip-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-slip transition. Furthermore, the stick-slip-separation kinematics is analyzed by establishing analytical criteria that predict the transition between stick, slip and separation of the interface. Stick-slip-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-slip motion can occur with greater preload and smaller voltage amplitude. Furthermore, a dimensionless parameter is proposed to predict the occurrence of stick-slip versus slip-separation motions, and its role in designing ultrasonic motors is discussed. It is shown that slip-separation motion is favorable for the slider velocity.

  14. Fault Slip Model of 2013 Lushan Earthquake Retrieved Based on GPS Coseismic Displacements

    Institute of Scientific and Technical Information of China (English)

    Mengkui Li; Shuangxi Zhang; Chaoyu Zhang; Yu Zhang


    Lushan Earthquake (~Mw 6.6) occurred in Sichuan Province of China on 20 April 2013, was the largest earthquake in Longmenshan fault belt since 2008 Wenchuan Earthquake. To better understand its rupture pattern, we focused on the influences of fault parameters on fault slips and performed fault slip inversion using Akaike’s Bayesian Information Criterion (ABIC) method. Based on GPS coseismic data, our inverted results showed that the fault slip was mainly confined at depths. The maximum slip amplitude is about 0.7 m, and the scalar seismic moment is about 9.47×1018 N·m. Slip pattern reveals that the earthquake occurred on the thrust fault with large dip-slip and small strike-slip, such a simple fault slip represents no second sub-event occurred. The Coulomb stress changes (DCFF) matched the most aftershocks with negative anomalies. The in-verted results demonstrated that the source parameters have significant impacts on fault slip distri-bution, especially on the slip direction and maximum displacement.

  15. Interfacial slip on a transverse-shear mode acoustic wave device (United States)

    Ellis, Jonathan S.; Hayward, Gordon L.


    This article describes a mathematical relationship between the slip parameter α and the slip length b for a slip boundary condition applied to the transverse-shear model for a quartz-crystal acoustic wave device. The theory presented here reduces empirical determination of slip to a one-parameter fit. It shows that the magnitude and phase of the slip parameter, which describes the relative motion of the surface and liquid in the transverse-shear model, can be linked to the slip length. Furthermore, the magnitude and phase of the slip parameter are shown to depend on one another. An experiment is described to compare the effects of liquid-surface affinity on the resonant properties of a transverse-shear mode wave device by applying different polar and nonpolar liquids to surfaces of different polarity. The theory is validated with slip values determined from the transverse-shear model and compared to slip length values from literature. Agreement with literature values of slip length is within one order of magnitude.

  16. Estimators of wheel slip for electric vehicles using torque and encoder measurements (United States)

    Boisvert, M.; Micheau, P.


    For the purpose of regenerative braking control in hybrid and electrical vehicles, recent studies have suggested controlling the slip ratio of the electric-powered wheel. A slip tracking controller requires an accurate slip estimation in the overall range of the slip ratio (from 0 to 1), contrary to the conventional slip limiter (ABS) which calls for an accurate slip estimation in the critical slip area, estimated at around 0.15 in several applications. Considering that it is not possible to directly measure the slip ratio of a wheel, the problem is to estimate the latter from available online data. To estimate the slip 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 slip estimation, a disturbance increasingly significant at low speed and low torque. Herein, two different extended Kalman observers of slip ratio were developed. The first calculates the slip 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 slip 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.

  17. Assessing the Updip Spatial Offset of Tremor and Slip during ETS Events in Cascadia (United States)

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


    We investigate the updip spatial overlap of tremor and slip during recent episodic tremor and slip (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 slip 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 slip are reflective of different physical conditions. While a clear offset of tremor and slip 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 slip and incorporated into slip models where parameters affecting the distribution and magnitude of slip are allowed to vary. These slip models are used to forward predict surface displacements and strains, which are then compared to the geodetic observations and inferred slip based on geodetic inversions. Results indicate that, while the tremor-derived slip distributions do a good job predicting the broad-scale surface deformation, the best-fit models have slip updip of the peak tremor activity. The fine-scale relationship of tremor and slip 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.

  18. Slow Slip History for the MEXICO Subduction Zone: 2005 Through 2011 (United States)

    Graham, Shannon; DeMets, Charles; Cabral-Cano, Enrique; Kostoglodov, Vladimir; Rousset, Baptiste; Walpersdorf, Andrea; Cotte, Nathalie; Lasserre, Cécile; McCaffrey, Robert; Salazar-Tlaczani, Luis


    To further our understanding of the seismically hazardous Mexico subduction zone, we estimate the first time-dependent slip distributions and Coulomb failure stress changes for the six major slow slip events (SSEs) that occurred below Mexico between late 2005 and mid-2011. Slip dist ributions are the first to be estimated from all continuous GPS data in central and southern Mexico, which better resolves slow slip in space and time than was previously possible in this region. Below Oaxaca, slip 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 slip accounts for deep slip within a previously noted gap between the Oaxaca and Guerrero SSE source regions. The slip that we estimate for the two SSEs that originated below Guerrero between 2005 and 2011 agrees with slip 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 slip below Guerrero intrudes up-dip into the potentially seismogenic region, presumably accounting for some of the missing slip within the well-described Guerrero seismic gap. In contrast, slow slip 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 slip deficit that accumulated in the down-dip region during this period.

  19. Modeling shallow slip deficit in large strike-slip earthquakes using simulations of spontaneous earthquake sequences in elasto-plastic media (United States)

    Kaneko, Y.; Fialko, Y.


    Slip inversions of several large strike-slip earthquakes point to coseismic slip deficit at shallow depths (Sierra El Mayor (Mexico) earthquake. Determining the origin of shallow slip deficit is important both for understanding physics of earthquakes and for estimating seismic hazard, as suppression of shallow rupture could greatly influence strong ground motion in the vicinity of active faults. Several mechanisms may be invoked to explain the deficit. A widely accepted interpretation is the presence of velocity-strengthening fault friction at shallow depths where the coseismic slip deficit is compensated by afterslip and interseismic creep. However, geodetic observations indicate that the occurrence of interseismic creep and afterslip at shallow depths is rather uncommon, except for certain locations near major creeping segments of mature faults and/or in areas with thick sedimentary covers with overpressurized pore fluids (e.g., Wei et al., 2009). Fialko et al. (2005) proposed that extensive inelastic failure of the shallow crust in the interseismic period or during earthquakes may result in coseismic slip deficit at shallow depths. In this work, we investigate whether inelastic failure of the shallow crust can lead to shallow coseismic slip deficit using simulations of spontaneous earthquake sequences on vertical planar strike-slip faults. To account for inelastic deformation, we incorporate off-fault plasticity into 2-D models of earthquake sequences on faults governed by laboratory-derived rate and state friction (Kaneko et al., 2010). Our preliminary results suggest that coseismic slip deficit could occur in a wide range of parameters that characterize inelastic material properties. We will report on our current efforts on identifying key parameters of fault friction and bulk rheology that link to the degree of coseismic slip deficit over multiple earthquake cycles.

  20. Experimental Modeling of Dynamic Shallow Dip-Slip Faulting (United States)

    Uenishi, K.


    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-slip 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-slip 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-slip 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

  1. Slipped upper femoral epiphysis: imaging of complications after treatment

    Energy Technology Data Exchange (ETDEWEB)

    Tins, B. [Robert Jones and Agnes Hunt Orthopaedic and District Hospital, Twmpath Lane, Oswestry, Shropshire (United Kingdom)], E-mail:; Cassar-Pullicino, V.; McCall, I. [Robert Jones and Agnes Hunt Orthopaedic and District Hospital, Twmpath Lane, Oswestry, Shropshire (United Kingdom)


    Slipped upper femoral epiphysis (SUFE) is a multifactorial condition usually affecting adolescents. Obesity is one risk factor, and as this is increasing the incidence of SUFE is likely to rise. Diagnosis and treatment are usually straightforward and carried out by orthopaedic surgeons. However, the recognition of post-treatment complications poses a much greater challenge. This article focuses on possible complications of surgical treatment of SUFE particularly. Chondrolysis, avascular necrosis, as well as other complications of treatment and conditions leading to premature osteoarthritis are discussed. Checklists for a systematic approach to post-treatment imaging are provided.

  2. Parameter identification and slip estimation of induction machine (United States)

    Orman, Maciej; Orkisz, Michal; Pinto, Cajetan T.


    This paper presents a newly developed algorithm for induction machine rotor speed estimation and parameter detection. The proposed algorithm is based on spectrum analysis of the stator current. The main idea is to find the best fit of motor parameters and rotor slip with the group of characteristic frequencies which are always present in the current spectrum. Rotor speed and parameters such as pole pairs or number of rotor slots are the results of the presented algorithm. Numerical calculations show that the method yields very accurate results and can be an important part of machine monitoring systems.

  3. Dynamic Weakening by Acoustic Fluidization during Stick-Slip Motion. (United States)

    Giacco, F; Saggese, L; de Arcangelis, L; Lippiello, E; Pica Ciamarra, M


    The unexpected weakness of some faults has been attributed to the emergence of acoustic waves that promote failure by reducing the confining pressure through a mechanism known as acoustic fluidization, also proposed to explain earthquake remote triggering. Here we validate this mechanism via the numerical investigation of a granular fault model system. We find that the stick-slip dynamics is affected only by perturbations applied at a characteristic frequency corresponding to oscillations normal to the fault, leading to gradual dynamical weakening as failure is approaching. Acoustic waves at the same frequency spontaneously emerge at the onset of failure in the absence of perturbations, supporting the relevance of acoustic fluidization in earthquake triggering.

  4. Photoinduced "stick-slip" on superhydrophilic semiconductor surfaces. (United States)

    Denison, Kieth R; Boxall, Colin


    Transparent mesoporous TiO2 (M-TiO2) thin films were prepared on quartz via a reverse micelle, sol-gel, spin-coating technique. Films were characterized by atomic force microscopy (AFM) and Raman and UV-vis spectroscopies and were found to be mostly anatase with low surface roughness (Rt approximately 5 nm). The time dependence of film photoinduced superhydrophilicity (PISH) was measured by observation of the spreading of a sessile water drop using a new, continuous measurement technique wherein the drop was first applied to the semiconductor surface and then was filmed while it and the underlying substrate were illuminated by 315 nm ultraband gap light. Results obtained at 100% relative humidity (RH) at 293 K showed that drops on M-TiO2 surfaces exhibited a photoinduced "stick-slip" behavior, the first time such an effect has been observed. The thermodynamic driving force for this photoinduced stick-slip was the departure of the system from capillary equilibrium as, with increasing illumination time, the concentration of surface Ti-OH groups increased and the equilibrium contact angle of the drop, theta0, decreased. A simple theoretical description of photoinduced stick-slip is derived and is used to calculate a value of the potential energy barrier associated with surface inhomogeneities that oppose onset of movement of the triple line, U = 6.63 x 10(-6) J m(-1). This is the first time that U has been quantified for a surface with photoinduced superhydrophilicity. Triple line retreat measurements on an evaporating drop on M-TiO2 in the dark, RH = 60%, T = 293 K, gave a value of U = 9.4 x 10(-6) J m(-1), indicating that U decreases upon UV illumination and that U in the light is primarily associated with inhomogeneities that are unaffected by an increase in the surface Ti-OH population, such as the physical roughness of the surface. In the dark evaporation experiment, the drop was found to retreat with an areal velocity of 1.48 x 10(-8) m2 s(-1). However, under UV

  5. Thermophoresis at a charged surface: the role of hydrodynamic slip. (United States)

    Morthomas, Julien; Würger, Alois


    By matching boundary layer hydrodynamics with slippage to the force-free flow at larger distances, we obtain the thermophoretic mobility of charged particles as a function of the Navier slip length b. A moderate value of b augments Ruckenstein's result by a term 2b/λ, where λ is the Debye length. If b exceeds the particle size a, the enhancement coefficient a/λ is independent of b but proportional to the particle size. Similar effects occur for transport driven by a salinity gradient or by an electric field.

  6. Additional slip of pectoralis major muscle – the costohumeralis

    Directory of Open Access Journals (Sweden)

    Rao TR


    Full Text Available We present a rare case of costohumeralis muscle, an accessory slip originating from the sixth rib near costochondral junction and running along the lower border of the pectoralis major muscle, inserting onto the medial epicondyle of the humerus on the right side. The occurrence of this costohumeralis muscle also showed a coincidental loss of the classical twisting of the tendinous insertion of the pectoralis major muscle, which proves that this muscle is variable in its development and attachment. Clinical considerations of such a variation include ulnar nerve entrapment and functionally limited abduction of humerus.

  7. Slip systems, dislocation boundaries and lattice rotations in deformed metals

    DEFF Research Database (Denmark)

    Winther, Grethe


    strains at room temperature are analysed. A major result is that, by contrast to previous beliefs, the boundaries align with specific crystallographic planes, which depend on the crystallographic grain orientation. This grain orientation dependence originates from an underlying dependence of the active...... of the mechanical anisotropy of rolled sheets. The rotation of the crystallographic lattice in each grain during deformation also exhibits grain orientation dependence, originating from the slip systems. A combined analysis of dislocation boundaries and lattice rotations concludes that the two phenomena are coupled...

  8. Fatigue Hardening and Nucleation of Persistent Slip Bands in Copper

    DEFF Research Database (Denmark)

    Pedersen, Ole Bøcker; Winter, A. T.


    that there is a large volume fraction of obstacles to plastic flow which are essentially non-deformable and give rise to inclusion stresses of considerable magnitude. The much lower hardening rates in cycles after saturation when persistent slip bands have formed suggest a lower volume fraction of obstacles......, as is observed by transmission electron microscopy. A simple composite model involving an inclusion stress, a bowing stress and a passing, stress accounts for the workhardening rates semi-quantitatively in terms of observed dislocation microstructures. Possible implications for polycrystals are considered....

  9. Topological Effects on Quantum Phase Slips in Superfluid Spin Transport (United States)

    Kim, Se Kwon; Tserkovnyak, Yaroslav


    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 slips. 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.

  10. Slip effects associated with Knudsen transport phenomena in porous media (United States)

    Frederking, T. H. K.; Hepler, W. A.; Khandhar, P. K.


    Porous media used in phase separators and thermomechanical pumps have been the subject of characterization efforts based on the Darcy permeability of laminar continuum flow. The latter is not always observed at low speed, in particular at permeabilities below 10 to the -9th/squared cm. The present experimental and theoretical studies address questions of slip effects associated with long mean free paths of gas flow at room temperature. Data obtained are in good agreement, within data uncertainty, with a simplified asymptotic Knudsen equation proposed for porous plugs on the basis of Knudsen's classical flow equation for long mean free paths.

  11. Abating Earthquake Effects on Buildings by Active Slip Brace Devices

    Directory of Open Access Journals (Sweden)

    Zekai Akbay


    Full Text Available A hybrid control system for reducing building vibration under a spectrum of earthquake load amplitudes is presented. The hybrid control is accomplished by an energy dissipation device called the active slip brace device (ASBD. The hybrid control system uses the ASBD to regulate the energy dissipation characteristics of the building during its response to earthquakes by utilizing active control principles. The ASBD consists of a Coulomb friction interface with a clamping mechanism on the interface. The clamping force on the friction interface is altered at short time intervals during building vibration. Computer simulations of building response with and without ASBD are compared.

  12. Corrected second-order slip boundary condition for fluid flows in nanochannels. (United States)

    Zhang, Hongwu; Zhang, Zhongqiang; Zheng, Yonggang; Ye, Hongfei


    A corrected second-order slip boundary condition is proposed to solve the Navier-Stokes equations for fluid flows confined in parallel-plate nanochannels. Compared with the classical second-order slip boundary condition proposed by Beskok and Karniadakis, the corrected slip boundary condition is not only dependent on the Knudsen number and the tangential momentum accommodation coefficient, but also dependent on the relative position of the slip surface in the Knudsen layer. For the fluid flows in slip-flow regime with the Knudsen number less than 0.3, Couette cell is investigated using molecular-dynamics simulations to verify Newtonian flow behaviors by examining the constitutive relationship between shear stress and strain rate. By comparing the velocity profiles of Poiseuille flows predicted from the Navier-Stokes equations with the corrected slip boundary condition with that from molecular-dynamics simulations, it is found that the flow behaviors in our models can be effectively captured.

  13. The seasonal dependence of cycle slip occurrence of GPS data over China low latitude region

    Institute of Scientific and Technical Information of China (English)


    The relationship of daily accumulated cycle slip occurrence with the season is analyzed using the GPS data observed in six GPS stations located in China low latitude region in 2001. It is found that the seasonal dependence of cycle slip oc-currence is evident. The cycle slip mainly occurs during the periods of two equinox months (March to May and September to October), and some correlative changes of the cycle slip occurrences over all six stations are exhibited in some special days. Considering the diurnal dependence of cycle slip, it can be inferred that the cycle slip occurrence with certain elevation limitation is related with the iono-spheric irregularities over this region.

  14. Slow slip hidden in the noise: the intermittence of tectonic release (United States)

    Frank, W.


    Referred to as slow slip events, the transient aseismic slip that occurs along plate boundaries can be indirectly characterized through colocated seismicity, such as tectonic tremor and low-frequency earthquakes (LFEs). Using the timing of cataloged LFE and tremor activity in Guerrero, Mexico and northern Cascadia, I decompose the inter-aseismic GPS displacement, defined as the surface deformation between previously detected slow slip events, into separate regimes of tectonic loading and release. In such a way, previously undetected slow slip events that produce on average less than a millimeter of surface deformation are extracted from the geodetic noise. These new observations demonstrate that the inter-aseismic period is not quiescent and that slow slip occurs much more often than previously thought. This suggests that the plate interface where slow slip and tremor occur is in fact strongly coupled and undergoes rapid cycles of stress accumulation and release.

  15. Large fault slip peaking at trench in the 2011 Tohoku-oki earthquake (United States)

    Sun, Tianhaozhe; Wang, Kelin; Fujiwara, Toshiya; Kodaira, Shuichi; He, Jiangheng


    During the 2011 magnitude 9 Tohoku-oki earthquake, very large slip occurred on the shallowest part of the subduction megathrust. Quantitative information on the shallow slip is of critical importance to distinguishing between different rupture mechanics and understanding the generation of the ensuing devastating tsunami. However, the magnitude and distribution of the shallow slip are essentially unknown due primarily to the lack of near-trench constraints, as demonstrated by a compilation of 45 rupture models derived from a large range of data sets. To quantify the shallow slip, here we model high-resolution bathymetry differences before and after the earthquake across the trench axis. The slip is determined to be about 62 m over the most near-trench 40 km of the fault with a gentle increase towards the trench. This slip distribution indicates that dramatic net weakening or strengthening of the shallow fault did not occur during the Tohoku-oki earthquake.


    Institute of Scientific and Technical Information of China (English)

    ZHANG Ren-liang; DI Qin-feng; WANG Xin-liang; DING Wei-peng; GONG Wei


    The apparent slip between solid wall and liquid is studied by using the Lattice Boltzmann Method (LBM) and the Shan-Chen multiphase model in this paper.With a no-slip bounce-back scheme applied to the interface,flow regimes under different wall wettabilities are investigated.Because of the wall wettability,liquid apparent slip is observed.Slip lengths for different wall wettabilities are found to collapse nearly onto a single curve as a function of the static contact angle,and thereby a relationship between apparent slip length and contact angle is suggested.Our results also show that the wall wettability leads to the formation of a low-density layer between solid wall and liquid,which produced apparent slip in the micro-scale.

  17. Slip-stacking Dynamics for High-Power Proton Beams at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Eldred, Jeffrey Scott [Indiana Univ., Bloomington, IN (United States)


    Slip-stacking is a particle accelerator configuration used to store two particle beams with different momenta in the same ring. The two beams are longitudinally focused by two radiofrequency (RF) cavities with a small frequency difference between them. Each beam is synchronized to one RF cavity and perturbed by the other RF cavity. Fermilab uses slip-stacking in the Recycler so as to double the power of the 120 GeV proton beam in the Main Injector. This dissertation investigates the dynamics of slip-stacking beams analytically, numerically and experimentally. In the analytic analysis, I find the general trajectory of stable slip-stacking particles and identify the slip-stacking parametric resonances. In the numerical analysis, I characterize the stable phase-space area and model the particle losses. In particular, I evaluate the impact of upgrading the Fermilab Booster cycle-rate from 15 Hz to 20 Hz as part of the Proton Improvement Plan II (PIP-II). The experimental analysis is used to verify my approach to simulating slip-stacking loss. I design a study for measuring losses from the longitudinal single-particle dynamics of slip-stacking as a function of RF cavity voltage and RF frequency separation. I further propose the installation of a harmonic RF cavity and study the dynamics of this novel slip-stacking configuration. I show the harmonic RF cavity cancels out parametric resonances in slip-stacking, reduces emittance growth during slip-stacking, and dramatically enhances the stable phase-space area. The harmonic cavity is expected to reduce slip-stacking losses to far exceed PIP-II requirements. These results raise the possibility of extending slip-stacking beyond the PIP-II era.

  18. A Network Inversion Filter combining GNSS and InSAR for tectonic slip modeling


    Bekaert, D.; P. Segall; Wright, TJ; Hooper, A.


    Studies of the earthquake cycle benefit from long-term time-dependent slip modeling, as it can be a powerful means to improve our understanding on the interaction of earthquake cycle processes such as interseismic, coseismic, postseismic, and aseismic slip. Observations from Interferometric Synthetic Aperture Radar (InSAR) allow us to model slip at depth with a higher spatial resolution than when using GNSS alone. While the temporal resolution of InSAR has typically been limited, the recent f...

  19. Neotectonics of interior Alaska and the late Quaternary slip rate along the Denali fault system (United States)

    Haeussler, Peter J.; Matmon, Ari; Schwartz, David P.; Seitz, Gordon G.


    The neotectonics of southern Alaska (USA) are characterized by a several hundred kilometers–wide zone of dextral transpressional that spans the Alaska Range. The Denali fault system is the largest active strike-slip fault system in interior Alaska, and it produced a Mw 7.9 earthquake in 2002. To evaluate the late Quaternary slip rate on the Denali fault system, we collected samples for cosmogenic surface exposure dating from surfaces offset by the fault system. This study includes data from 107 samples at 19 sites, including 7 sites we previously reported, as well as an estimated slip rate at another site. We utilize the interpreted surface ages to provide estimated slip rates. These new slip rate data confirm that the highest late Quaternary slip rate is ∼13 mm/yr on the central Denali fault near its intersection with the eastern Denali and the Totschunda faults, with decreasing slip rate both to the east and west. The slip rate decreases westward along the central and western parts of the Denali fault system to 5 mm/yr over a length of ∼575 km. An additional site on the eastern Denali fault near Kluane Lake, Yukon, implies a slip rate of ∼2 mm/yr, based on geological considerations. The Totschunda fault has a maximum slip rate of ∼9 mm/yr. The Denali fault system is transpressional and there are active thrust faults on both the north and south sides of it. We explore four geometric models for southern Alaska tectonics to explain the slip rates along the Denali fault system and the active fault geometries: rotation, indentation, extrusion, and a combination of the three. We conclude that all three end-member models have strengths and shortcomings, and a combination of rotation, indentation, and extrusion best explains the slip rate observations.

  20. Slip Model Used for Prediction of r Value of BCC Metal Sheets from ODF Coefficients

    Institute of Scientific and Technical Information of China (English)


    Different slip models were used for prediction of rvalue of BCC metal sheets from ODF coefficients. According to the maximum plastic work theory developed by Bishop and Hill, it is expected that the higher of Taylor factors given by a slip model, the better predictio nobtained based on the model. From this point of view, a composed slip model of BCC metals was presented. Based on the model, the agreement of predicted rvalues for deep drawing steels with experimental ones is excellent.