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Sample records for controlling arterial-lymphatic conduits

  1. CONDUIT: Control Designer's Unified Interface

    NASA Technical Reports Server (NTRS)

    Levine, William S.; Tischler, Mark B.

    1999-01-01

    CONDUIT, which stands for control designer's unified interface, is a computer software package. Its purpose is to assist a human control system designer in designing control systems for aircraft. At the present time CONDUIT is being used by most of the major U. S. rotorcraft and fixed-wing aircraft manufacturers to assist in the design of stability and control augmentation systems. Work is also continuing on the development of additional features for CONDUIT, including tools for analyzing the sensitivity of solutions, and on further enhancements to the basic package. The purpose of this paper is to describe CONDUIT, its operation, and the sensitivity tools that are being developed for inclusion in the next release of the package.

  2. Controlling Wavebreaking in a Viscous Fluid Conduit

    NASA Astrophysics Data System (ADS)

    Anderson, Dalton; Maiden, Michelle; Hoefer, Mark

    2015-11-01

    This poster will present a new technique in the experimental investigation of dispersive hydrodynamics. In shallow water flows, internal ocean waves, superfluids, and optical media, wave breaking can be resolved by a dispersive shock wave (DSW). In this work, an experimental method to control the location of DSW formation (gradient catastrophe) is explained. The central idea is to convert an initial value problem (Riemann problem) into an equivalent boundary value problem. The system to which this technique is applied is a fluid conduit resulting from high viscosity contrast between a buoyant interior and heavier exterior fluid. The conduit cross-sectional area is modeled by a nonlinear, conservative, dispersive, third order partial differential equation. Using this model, the aim is to predict the breaking location of a DSW by controlling one boundary condition. An analytical expression for this boundary condition is derived by solving the dispersionless equation backward in time from the desired step via the method of characteristics. This is used in experiment to generate an injection rate profile for a high precision piston pump. This translates to the desired conduit shape. Varying the jump height and desired breaking location indicates good control of DSW formation. This result can be improved by deriving a conduit profile by numerical simulation of the full model equation. Controlling the breaking location of a DSW allows for the investigation of dynamics independent of the boundary. Support provided by NSF CAREER DMS-1255422 , NSF EXTREEMS.

  3. CONDUIT: A New Multidisciplinary Integration Environment for Flight Control Development

    NASA Technical Reports Server (NTRS)

    Tischler, Mark B.; Colbourne, Jason D.; Morel, Mark R.; Biezad, Daniel J.; Levine, William S.; Moldoveanu, Veronica

    1997-01-01

    A state-of-the-art computational facility for aircraft flight control design, evaluation, and integration called CONDUIT (Control Designer's Unified Interface) has been developed. This paper describes the CONDUIT tool and case study applications to complex rotary- and fixed-wing fly-by-wire flight control problems. Control system analysis and design optimization methods are presented, including definition of design specifications and system models within CONDUIT, and the multi-objective function optimization (CONSOL-OPTCAD) used to tune the selected design parameters. Design examples are based on flight test programs for which extensive data are available for validation. CONDUIT is used to analyze baseline control laws against pertinent military handling qualities and control system specifications. In both case studies, CONDUIT successfully exploits trade-offs between forward loop and feedback dynamics to significantly improve the expected handling, qualities and minimize the required actuator authority. The CONDUIT system provides a new environment for integrated control system analysis and design, and has potential for significantly reducing the time and cost of control system flight test optimization.

  4. Apparatus for controlling fluid flow in a conduit wall

    DOEpatents

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

    2003-05-13

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

  5. System and method for bidirectional flow and controlling fluid flow in a conduit

    DOEpatents

    Ortiz, M.G.

    1999-03-23

    A system for measuring bidirectional flow, including backflow, of fluid in a conduit is disclosed. The system utilizes a structural mechanism to create a pressure differential in the conduit. Pressure sensors are positioned upstream from the mechanism, at the mechanism, and downstream from the mechanism. Data from the pressure sensors are transmitted to a microprocessor or computer, and pressure differential detected between the pressure sensors is then used to calculate the backflow. Control signals may then be generated by the microprocessor or computer to shut off valves located in the conduit, upon the occurrence of backflow, or to control flow, total material dispersed, etc. in the conduit. 3 figs.

  6. System and method for bidirectional flow and controlling fluid flow in a conduit

    DOEpatents

    Ortiz, Marcos German

    1999-01-01

    A system for measuring bidirectional flow, including backflow, of fluid in a conduit. The system utilizes a structural mechanism to create a pressure differential in the conduit. Pressure sensors are positioned upstream from the mechanism, at the mechanism, and downstream from the mechanism. Data from the pressure sensors are transmitted to a microprocessor or computer, and pressure differential detected between the pressure sensors is then used to calculate the backflow. Control signals may then be generated by the microprocessor or computer to shut off valves located in the conduit, upon the occurrence of backflow, or to control flow, total material dispersed, etc. in the conduit.

  7. The Development of the CONDUIT Advanced Control System Design and Evaluation Interface with a Case Study Application to an Advanced Fly by Wire Helicopter Design

    NASA Technical Reports Server (NTRS)

    Colbourne, Jason

    1999-01-01

    This report details the development and use of CONDUIT (Control Designer's Unified Interface). CONDUIT is a design tool created at Ames Research Center for the purpose of evaluating and optimizing aircraft control systems against handling qualities. Three detailed design problems addressing the RASCAL UH-60A Black Hawk are included in this report to show the application of CONDUIT to helicopter control system design.

  8. Causes and Control of Corrosion in Buried-Conduit Heat Distribution Systems

    DTIC Science & Technology

    1991-07-01

    line. Dissolved carbon dioxide in the condensate can be minimized, in part, by avoiding the use of high bicarbonate -alkalinity feedwater and by...sulfite with the pH adjusted to 9 to 10 using caustic soda . High-temperature Same as that for medium- temperature. *Source: R.T. Blake, Water Treatment...34 exhibit sufficient impact, abrasion , and ductility characteristics that the coated conduits can be handled, stored, and installed using recommended

  9. Detection of conduit-controlled ground-water flow in northwestern Puerto Rico using aerial photograph interpretation and geophysical methods

    USGS Publications Warehouse

    Rodríguez-Martínez, Jesús; Richards, Ronald T.

    2000-01-01

    The development potential of ground-water resources in the karst limestone of northwestern Puerto Rico, in an area extending from the Río Camuy to Aguadilla, is uncertain as a result of limited knowledge of the location of areas where a high density of cavities (interconnected fractures, conduits, and other dissolution features) might suggest the occurrence of high water yields. The presence in northwestern Puerto Rico of numerous coastal submarine springs, cavernous porosity in some of the wells, and rivers with entrenched and underground paths, indicate that it is probable that water-bearing, subterranean interconnected cavities occur in the area between the Río Camuy and Aguadilla. The number of exploratory wells needed to determine the location of these conduits or zones of enhanced secondary porosity could be substantially reduced if more information were available about the location of these subterranean features, greatly reducing the drilling costs associated with a trial-and-error exploratory process. A 3-year study was conducted by the U.S. Geological Survey, in cooperation with the Puerto Rico Aqueduct and Sewer Authority, to detect the presence of cavities that might suggest the occurrence of conduit-controlled groundwater flow. Aerial photographs, geologic and topographic maps, and field reconnaissance were used to identify such linear terrain features as ridges, entrenched canyons, and fracture traces. Natural potential and gravity geophysical methods were also used. The following sites were selected for the aerial photograph interpretation and geophysical testing: Caimital Bajo uplands and former Ramey Air Force Base in Aguadilla; Quebrada de los Cedros between Aguadilla and Isabela; the University of Puerto Rico Agricultural Experiment Station, Otilio dairy farm, and Pozo Brujo in Isabela; the Monte Encantado area in Moca and Isabela; and the Rio Camuy cave system in Hatillo and Camuy. In general, the degree of success varied with site and the

  10. Subglacial conduits in sediments

    NASA Astrophysics Data System (ADS)

    Hewitt, Ian

    2016-04-01

    Much of the current understanding of subglacial hydrology is based on the R-channel type model, in which turbulent dissipation and melting causes a roughly semi-circular incision upwards into the ice. The prevalence of such R-channels beneath the Greenland and Antarctic ice sheets is poorly known. Beneath sediment-based ice, distributed water flow may prevail, or some form of conduits may still form due to a combination of upwards melting as well as downwards erosion into the subglacial sediments (often referred to as a canal). This study examines the dynamics of such conduits, and implications for large-scale subglacial drainage. Although a relatively standard set of equations has developed to model the evolution and efficiency of R-channels, models of sediment-floored conduits are much less well established; previous models assume steady state, or make ad hoc assumptions about the balance of processes controlling the channel walls. In this study I suggest a (relatively) simple model analogous to that for an R-channel. The model requires consideration of the energy balance that results in melting of the ice roof, and also the erosion, deposition, and creep of the sediments. Implications for the evolution of large-scale drainage systems over subglacial sediment will be discussed, for subglacial floods in Antarctica, and for subglacial erosion and landform development.

  11. Fluid mechanic phenomena relating to flow control in conduits and pumps

    NASA Astrophysics Data System (ADS)

    Bayazit, Yilmaz

    The attainment of controlled homogenized fluid flow is a major issue in the efficient utilization of internal flows for applications as diverse as heat exchange, electrostatic filtration, water purification, particle conveyance, swirl control, and waste disposal. Among the candidate methodologies for accomplishing the homogenization task, perforated plates provide exceptional versatility and adaptability. The principle that underlies perforated plate flow control is the tendency of a flowing fluid to seek the path of least resistance. This tendency is coupled with the capability of the fluid to "see" what lies ahead, enabling it to adjust its trajectory. That capability is due to streamwise diffusion, which transfers information both upstream and downstream. In contrast, advection is a one-way information transfer mechanism, the direction of transfer coinciding with the direction of fluid motion. The degree of homogenization afforded by perforated plates depends on several geometrical and operating parameters. The geometrical parameters include: (a) plate porosity, (b) plate thickness, (c) aperture diameter, (d) pattern of aperture deployment, and (e) distance between apertures. With respect to operating parameters, those investigated here encompass (f) fluid velocity, (g) flow regime, and (h) angle of attack. Nondimensionalization diminished the total number of parameters to five. Numerical simulation was employed to solve the three-dimensional flow covering a Reynolds number range from 0.01 to 25,000. Results extracted from the solutions included dimensionless pressure drop, downstream distance for disturbance decay, vector diagrams and streamlines, and flow regime boundaries. A paradox where the pressure drop for a thin plate exceeded that for a thick plate was rationalized. The pressure drop characteristics of a perforated plate are akin to those for a porous medium. The Darcy-Forchheimer pressure drop model was extended into the turbulent flow regime for the

  12. Controlled release of vascular endothelial growth factor using poly-lactic-co-glycolic acid microspheres: In vitro characterization and application in polycaprolactone fumarate nerve conduits

    PubMed Central

    Rui, Jing; Dadsetan, Mahrokh; Runge, M. Brett; Spinner, Robert J.; Yaszemski, Michael J.; Windebank, Anthony J.; Wang, Huan

    2014-01-01

    Vascular endothelial growth factor (VEGF) is a potent angiogenic stimulator. Controlled release of such stimulators may enhance and guide the vascularization process, and when applied in a nerve conduit may play a role in nerve regeneration. We report the fabrication and in vitro characterization of VEGF encapsulating poly-lactic-co-glycolic acid (PLGA) microspheres and the in vivo application of nerve conduits supplemented with VEGF-containing microspheres. PLGA microspheres containing VEGF were prepared by the double emulsion-solvent evaporation technique. This yielded 83.16% of the microspheres with a diameter < 53 µm. VEGF content measured by ELISA indicated 93.79 ±10.64% encapsulation efficiency. Release kinetics were characterized by an initial burst release of 67.6±8.25% within the first 24 hours, followed by consistent release of approximately 0.34% per day for 4 weeks. Bioactivity of the released VEGF was tested by human umbilical vein endothelial cell (HUVEC) proliferation assay. VEGF released at all time points enhanced HUVEC proliferation confirming that VEGF retained its bioactivity through the 4-week time period. When the microsphere delivery system was placed in a biosynthetic nerve scaffold, robust nerve regeneration was observed. This study established a novel system for controlled release of growth factors and enables in vivo studies of nerve conduits conditioned with this system. PMID:22019759

  13. Stability of volcanic conduits during explosive eruptions

    NASA Astrophysics Data System (ADS)

    Aravena, Álvaro; de'Michieli Vitturi, Mattia; Cioni, Raffaello; Neri, Augusto

    2017-06-01

    Geological evidences of volcanic conduit widening are common in most pyroclastic deposits (e.g. presence of lithic fragments from different depths), suggesting a continuous modification of the conduit geometry during volcanic eruptions. However, the controlling factors of the mechanisms driving conduit enlargement (e.g. erosion, local collapse) are still partially unclear, as well as the influence of conduit geometry on the eruptive dynamics. Although numerical models have been systematically employed to study volcanic conduits, their mechanical stability and the eruptive dynamics related to non-cylindrical conduits have been poorly addressed. We present here a 1D steady-state model which includes the main processes experimented by ascending magmas (i.e. crystallization, rheological changes, fragmentation, drag forces, outgassing and degassing), and the application of two mechanical stability criteria (Mohr-Coulomb and Mogi-Coulomb), in order to study the collapse conditions of volcanic conduits during a representative explosive rhyolitic eruption. It emerges that mechanical stability of volcanic conduits is mainly controlled by its radial dimension, and a minimum radius for reaching stable conditions can be computed, as a function of water content and inlet overpressure. Additionally, for a set of input parameters thought typical of explosive rhyolitic volcanism, we estimated a minimum magma flux for developing a mechanically stable conduit ( 7 • 107 - 3 • 108 kg/s). Results are consistent with the unsteady character usually observed in sub-Plinian eruptions, opposite to mainly stationary Plinian eruptions, commonly characterized by higher magma discharge rates. We suggest that cylindrical conduits represent a mechanically stable configuration only for large radii. Because the instability conditions are not uniform along the conduit, the widening processes probably lead to conduit geometries with depth-varying width. Consequently, as our model is able to

  14. Seal arrangement for intersecting conduits

    DOEpatents

    Goedicke, Friedrich E.

    1980-01-01

    A seal arrangement in which two intersecting conduits are sealed from each other. A sleeve insert is locked in a sealed relationship within one conduit enclosing the openings of the intersecting conduit.

  15. Structural controls on karstic conduits in a collisional orogen (Sierra de las Nieves, Betic Cordillera, S Spain)

    NASA Astrophysics Data System (ADS)

    Pedrera, A.; Luque-Espinar, J. A.; Martos-Rosillo, S.; Pardo-Igúzquiza, E.; Durán-Valsero, J. J.; Martínez-Moreno, F.; Guardiola-Albert, C.

    2015-06-01

    We characterize the fracture pattern, including both meso-scale joints and macro-scale faults, within the central sector of Sierra de las Nieves (Betic Cordillera, S Spain), which contains one of the largest karstification systems in Europe. Structural data were compared with the direction pattern of the karstic conduit network of the largest caves. Carbonate rocks were deformed in a collisional setting and exposed at the surface since the early Miocene. Normal and normal-oblique faults trending NW-SE to WNW-ESE are the most prominent brittle structures, having formed coevally with shorter NE-SW normal to normal-dextral after the main thrusting phase. In addition, two main open joint sets striking NW-SE and NE-SW developed on a broad scale. Orthogonal normal faults and open joints suggest an extensional setting characterized by horizontal minimum (S3) and intermediate (S2) stress axes of similar magnitudes that intermittently shifted their positions during the middle-to-late Miocene. Vertical water flow coming from direct recharge sectors tends to infiltrate across these high-dipping faults, mainly concentrating at fault intersections, thus favoring sub-vertical conduit formation within the vadose zone. Horizontal paleo-phreatic levels are perched linked to the recent uplift undergone by the sector, giving us the opportunity to analyze the incidence of fractures at the phreatic zone. Joint sets determine the hydraulic anisotropy within the former phreatic levels. Because our study illustrates the primary role of diverse tectonic structures during massive multiphase cave development above and below the water table, it could contribute to better constraining of the models of karstic conduit formation.

  16. Multicriteria Gain Tuning for Rotorcraft Flight Controls (also entitled The Development of the Conduit Advanced Control System Design and Evaluation Interface with a Case Study Application Fly by Wire Helicopter Design)

    NASA Technical Reports Server (NTRS)

    Biezad, Daniel

    1997-01-01

    Handling qualities analysis and control law design would seem to be naturally complimenting components of aircraft flight control system design, however these two closely coupled disciplines are often not well integrated in practice. Handling qualities engineers and control system engineers may work in separate groups within an aircraft company. Flight control system engineers and handling quality specialists may come from different backgrounds and schooling and are often not aware of the other group's research. Thus while the handling qualities specifications represent desired aircraft response characteristics, these are rarely incorporated directly in the control system design process. Instead modem control system design techniques are based on servo-loop robustness specifications, and simple representations of the desired control response. Comprehensive handling qualities analysis is often left until the end of the design cycle and performed as a check of the completed design for satisfactory performance. This can lead to costly redesign or less than satisfactory aircraft handling qualities when the flight testing phase is reached. The desire to integrate the fields of handling qualities and flight,control systems led to the development of the CONDUIT system. This tool facilitates control system designs that achieve desired handling quality requirements and servo-loop specifications in a single design process. With CONDUIT, the control system engineer is now able to directly design and control systems to meet the complete handling specifications. CONDUIT allows the designer to retain a preferred control law structure, but then tunes the system parameters to meet the handling quality requirements.

  17. Conduit purging device and method

    NASA Technical Reports Server (NTRS)

    Wilks, Michael T. (Inventor)

    2011-01-01

    A device for purging gas comprises a conduit assembly defining an interior volume. The conduit assembly comprises a first conduit portion having an open first end and an open second end and a second conduit portion having an open first end and a closed second end. The open second end of the first conduit portion is disposed proximate to the open first end of the second conduit portion to define a weld region. The device further comprises a supply element supplying a gas to the interior volume at a substantially constant rate and a vent element venting the gas from the interior volume at a rate that maintains the gas in the interior volume within a pressure range suitable to hold a weld bead in the weld region in equilibrium during formation of a weld to join the first conduit portion and the second conduit portion.

  18. Seal between metal and ceramic conduits

    DOEpatents

    Underwood, Richard Paul; Tentarelli, Stephen Clyde

    2015-02-03

    A seal between a ceramic conduit and a metal conduit of an ion transport membrane device consisting of a sealing surface of ceramic conduit, a sealing surface of ceramic conduit, a single gasket body, and a single compliant interlayer.

  19. Getting Terrestrial Carbon into the Aquatic Conduit: Riparian peat controls from daily to centennial time-scales

    NASA Astrophysics Data System (ADS)

    Bishop, Kevin; Ledesma, Jose; Grabs, Thomas; Wallin, Marcus; Schiff, Sherry; Campeau, Audrey; Köhler, Stephan; Leith, Fraser

    2015-04-01

    Riparian zones (RZ) are important sources of biogenic carbon (both dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC)) reaching surface waters. This is the so-called "aquatic conduit" that returns large quantities of terrestrial carbon to the atmosphere. But it is often just a narrow 'dominant source layer' (DSL) within the riparian profile that is responsible of most of the carbon production and water to surface waters. But how long can this fraction of the RZ sustain lateral DOC/DIC fluxes as the sole source of exported carbon? This study estimates this theoretical turnover time of carbon and water in the DSL by comparing carbon/water pools and lateral fluxes in the DSL of 13 riparian profiles in northern Sweden. The thickness of the DSL was 36 ± 18 (±SD) cm, i.e. only about one third of the 1 metre deep riparian profile. The 13 RZ exported 8.7 ± 6.5 g C m-2 year-1. The estimated C turnover times were of the order of hundreds to thousands of years, while water residence time varied from hours to weeks. Net ecosystem production in the RZ can maintain the C export, including inorganic C, without drawing down the riparian pools. This was supported by measurements of stream DO14C that indicate modern carbon as the predominant fraction exported. Upscaling these results using representative data sets of stream DOC and CO2 concentrations, an empirically derived gas transfer model and the characteristics of a virtual stream network of Sweden enables us to present national CO2 emission and DOC export estimates for all Swedish headwater streams. These results further underline the importance of the riparian zone for terrestrial carbon export in the boreal/hemiboreal zone.

  20. Flexible cryogenic conduit

    SciTech Connect

    Brindza, P.D.; Wines, R.R.; Takacs, J.J.

    1999-12-21

    A flexible and relatively low cost cryogenic conduit is described. The flexible cryogenic conduit of the present invention comprises a first inner corrugated tube with single braided serving, a second outer corrugated tube with single braided serving concentric with the inner corrugated tube, and arranged outwardly about the periphery of the inner corrugated tube and between the inner and outer corrugated tubes: a superinsulation layer; a one half lap layer of polyester ribbon; a one half lap layer of copper ribbon; a spirally wound refrigeration tube; a second one half lap layer of copper ribbon; a second one half lap layer of polyester ribbon; a second superinsulation layer; a third one half lap layer of polyester ribbon; and a spirally wound stretchable and compressible filament.

  1. Flexible cryogenic conduit

    DOEpatents

    Brindza, Paul Daniel; Wines, Robin Renee; Takacs, James Joseph

    1999-01-01

    A flexible and relatively low cost cryogenic conduit is described. The flexible cryogenic conduit of the present invention comprises a first inner corrugated tube with single braided serving, a second outer corrugated tube with single braided serving concentric with the inner corrugated tube, and arranged outwardly about the periphery of the inner corrugated tube and between the inner and outer corrugated tubes: a superinsulation layer; a one half lap layer of polyester ribbon; a one half lap layer of copper ribbon; a spirally wound refrigeration tube; a second one half lap layer of copper ribbon; a second one half lap layer of polyester ribbon; a second superinsulation layer; a third one half lap layer of polyester ribbon; and a spirally wound stretchable and compressible filament.

  2. Portable conduit retention apparatus for releasably retaining a conduit therein

    DOEpatents

    Metzger, Richard H.

    1998-01-01

    Portable conduit retention apparatus for releasably retaining a conduit therein. The apparatus releasably retains the conduit out of the way of nearby personnel and equipment. The apparatus includes a portable support frame defining a slot therein having an open mouth portion in communication with the slot for receiving the conduit through the open mouth portion and into the slot. A retention bar is pivotally connected to the support frame adjacent the mouth portion for releasably retaining the conduit in the slot. The retention bar freely pivots to a first position, so that the mouth portion is unblocked in order that the conduit is received through the mouth portion and into the slot. In addition, the retention bar freely pivots to a second position, so that the mouth portion is blocked in order that the conduit is retained in the slot. The conduit is released from the slot by pivoting the retention bar to the first position to unblock the mouth portion and thereafter manipulating the conduit from the slot and through the mouth portion. The apparatus may further include a mounting member attached to the support frame for mounting the apparatus on a vertical support surface. Another embodiment of the apparatus includes a shoe assembly of predetermined weight removably connected to the support frame for resting the apparatus on a floor in such a manner that the apparatus is substantially stationary on the floor.

  3. Portable conduit retention apparatus for releasably retaining a conduit therein

    DOEpatents

    Metzger, R.H.

    1998-07-07

    Portable conduit retention apparatus is described for releasably retaining a conduit therein. The apparatus releasably retains the conduit out of the way of nearby personnel and equipment. The apparatus includes a portable support frame defining a slot therein having an open mouth portion in communication with the slot for receiving the conduit through the open mouth portion and into the slot. A retention bar is pivotally connected to the support frame adjacent the mouth portion for releasably retaining the conduit in the slot. The retention bar freely pivots to a first position, so that the mouth portion is unblocked in order that the conduit is received through the mouth portion and into the slot. In addition, the retention bar freely pivots to a second position, so that the mouth portion is blocked in order that the conduit is retained in the slot. The conduit is released from the slot by pivoting the retention bar to the first position to unblock the mouth portion and thereafter manipulating the conduit from the slot and through the mouth portion. The apparatus may further include a mounting member attached to the support frame for mounting the apparatus on a vertical support surface. Another embodiment of the apparatus includes a shoe assembly of predetermined weight removably connected to the support frame for resting the apparatus on a floor in such a manner that the apparatus is substantially stationary on the floor. 6 figs.

  4. Conduit Coating Abrasion Testing

    NASA Technical Reports Server (NTRS)

    Sullivan, Mary K.

    2013-01-01

    During my summer internship at NASA I have been working alongside the team members of the RESTORE project. Engineers working on the RESTORE project are creating ·a device that can go into space and service satellites that no longer work due to gas shortage or other technical difficulties. In order to complete the task of refueling the satellite a hose needs to be used and covered with a material that can withstand effects of space. The conduit coating abrasion test will help the researchers figure out what type of thermal coating to use on the hose that will be refueling the satellites. The objective of the project is to determine whether or not the conduit coating will withstand the effects of space. For the RESTORE project I will help with various aspects of the testing that needed to be done in order to determine which type of conduit should be used for refueling the satellite. During my time on the project I will be assisting with wiring a relay board that connected to the test set up by soldering, configuring wires and testing for continuity. Prior to the testing I will work on creating the testing site and help write the procedure for the test. The testing will take place over a span of two weeks and lead to an informative conclusion. Working alongside various RESTORE team members I will assist with the project's documentation and records. All in all, throughout my internship at NASA I hope to learn a number of valuable skills and be a part of a hard working team of engineers.

  5. A Controlled Design of Aligned and Random Nanofibers for 3D Bi-functionalized Nerve Conduits Fabricated via a Novel Electrospinning Set-up

    PubMed Central

    Kim, Jeong In; Hwang, Tae In; Aguilar, Ludwig Erik; Park, Chan Hee; Kim, Cheol Sang

    2016-01-01

    Scaffolds made of aligned nanofibers are favorable for nerve regeneration due to their superior nerve cell attachment and proliferation. However, it is challenging not only to produce a neat mat or a conduit form with aligned nanofibers but also to use these for surgical applications as a nerve guide conduit due to their insufficient mechanical strength. Furthermore, no studies have been reported on the fabrication of aligned nanofibers and randomly-oriented nanofibers on the same mat. In this study, we have successfully produced a mat with both aligned and randomly-oriented nanofibers by using a novel electrospinning set up. A new conduit with a highly-aligned electrospun mat is produced with this modified electrospinning method, and this proposed conduit with favorable features, such as selective permeability, hydrophilicity and nerve growth directional steering, were fabricated as nerve guide conduits (NGCs). The inner surface of the nerve conduit is covered with highly aligned electrospun nanofibers and is able to enhance the proliferation of neural cells. The central part of the tube is double-coated with randomly-oriented nanofibers over the aligned nanofibers, strengthening the weak mechanical strength of the aligned nanofibers. PMID:27021221

  6. A Controlled Design of Aligned and Random Nanofibers for 3D Bi-functionalized Nerve Conduits Fabricated via a Novel Electrospinning Set-up.

    PubMed

    Kim, Jeong In; Hwang, Tae In; Aguilar, Ludwig Erik; Park, Chan Hee; Kim, Cheol Sang

    2016-03-29

    Scaffolds made of aligned nanofibers are favorable for nerve regeneration due to their superior nerve cell attachment and proliferation. However, it is challenging not only to produce a neat mat or a conduit form with aligned nanofibers but also to use these for surgical applications as a nerve guide conduit due to their insufficient mechanical strength. Furthermore, no studies have been reported on the fabrication of aligned nanofibers and randomly-oriented nanofibers on the same mat. In this study, we have successfully produced a mat with both aligned and randomly-oriented nanofibers by using a novel electrospinning set up. A new conduit with a highly-aligned electrospun mat is produced with this modified electrospinning method, and this proposed conduit with favorable features, such as selective permeability, hydrophilicity and nerve growth directional steering, were fabricated as nerve guide conduits (NGCs). The inner surface of the nerve conduit is covered with highly aligned electrospun nanofibers and is able to enhance the proliferation of neural cells. The central part of the tube is double-coated with randomly-oriented nanofibers over the aligned nanofibers, strengthening the weak mechanical strength of the aligned nanofibers.

  7. Design of barrier coatings on kink-resistant peripheral nerve conduits

    PubMed Central

    Clements, Basak Acan; Bushman, Jared; Murthy, N Sanjeeva; Ezra, Mindy; Pastore, Christopher M; Kohn, Joachim

    2016-01-01

    Here, we report on the design of braided peripheral nerve conduits with barrier coatings. Braiding of extruded polymer fibers generates nerve conduits with excellent mechanical properties, high flexibility, and significant kink-resistance. However, braiding also results in variable levels of porosity in the conduit wall, which can lead to the infiltration of fibrous tissue into the interior of the conduit. This problem can be controlled by the application of secondary barrier coatings. Using a critical size defect in a rat sciatic nerve model, the importance of controlling the porosity of the nerve conduit walls was explored. Braided conduits without barrier coatings allowed cellular infiltration that limited nerve recovery. Several types of secondary barrier coatings were tested in animal studies, including (1) electrospinning a layer of polymer fibers onto the surface of the conduit and (2) coating the conduit with a cross-linked hyaluronic acid-based hydrogel. Sixteen weeks after implantation, hyaluronic acid-coated conduits had higher axonal density, displayed higher muscle weight, and better electrophysiological signal recovery than uncoated conduits or conduits having an electrospun layer of polymer fibers. This study indicates that braiding is a promising method of fabrication to improve the mechanical properties of peripheral nerve conduits and demonstrates the need to control the porosity of the conduit wall to optimize functional nerve recovery. PMID:26977288

  8. Sciatic nerve regeneration by transplantation of Schwann cells via erythropoietin controlled-releasing polylactic acid/multiwalled carbon nanotubes/gelatin nanofibrils neural guidance conduit.

    PubMed

    Salehi, Majid; Naseri-Nosar, Mahdi; Ebrahimi-Barough, Somayeh; Nourani, Mohammdreza; Khojasteh, Arash; Hamidieh, Amir-Ali; Amani, Amir; Farzamfar, Saeed; Ai, Jafar

    2017-07-04

    The current study aimed to enhance the efficacy of peripheral nerve regeneration using an electrically conductive biodegradable porous neural guidance conduit for transplantation of allogeneic Schwann cells (SCs). The conduit was produced from polylactic acid (PLA), multiwalled carbon nanotubes (MWCNTs), and gelatin nanofibrils (GNFs) coated with the recombinant human erythropoietin-loaded chitosan nanoparticles (rhEpo-CNPs). The PLA/MWCNTs/GNFs/rhEpo-CNPs conduit had the porosity of 85.78 ± 0.70%, the contact angle of 77.65 ± 1.91° and the ultimate tensile strength and compressive modulus of 5.51 ± 0.13 MPa and 2.66 ± 0.34 MPa, respectively. The conduit showed the electrical conductivity of 0.32 S cm(-1) and lost about 11% of its weight after 60 days in normal saline. The produced conduit was able to release the rhEpo for at least 2 weeks and exhibited favorable cytocompatibility towards SCs. For functional analysis, the conduit was seeded with 1.5 × 10(4) SCs and implanted into a 10 mm sciatic nerve defect of Wistar rat. After 14 weeks, the results of sciatic functional index, hot plate latency, compound muscle action potential amplitude, weight-loss percentage of wet gastrocnemius muscle and Histopathological examination using hematoxylin-eosin and Luxol fast blue staining demonstrated that the produced conduit had comparable nerve regeneration to the autograft, as the gold standard to bridge the nerve gaps. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2017. © 2017 Wiley Periodicals, Inc.

  9. Preclinical evaluations of acellular biological conduits for peripheral nerve regeneration

    PubMed Central

    Liao, I-Chien; Wan, Hua; Qi, Shijie; Cui, Cunqi; Patel, Paarun; Sun, Wendell

    2013-01-01

    Various types of natural biological conduits have been investigated as alternatives to the current surgical standard approach for peripheral nerve injuries. Autologous nerve graft, the current gold standard for peripheral nerve damage, is limited by clinical challenges such as donor-site morbidity and limited availability. The purpose of this study was to evaluate the efficacy of using acellular xenographic conduits (nerve, artery, and dermis) for the repair of a 1.2 cm critical size defect of peripheral nerve in a rodent model. Four months post surgery, the animal group receiving acellular artery as a nerve conduit showed excellent physiological outcome in terms of the prevention of muscle atrophy and foot ulcer. Histological assessment of the bridged site revealed excellent axon regeneration, as opposed to the nonrepaired control group or the group receiving dermal conduit. Finally, the study evaluated the potential improvement via the addition of undifferentiated mesenchymal stem cells into the artery conduit during the bridging procedure. The mesenchymal stem cell–dosed artery conduit group resulted in significantly higher concentration of regenerated axons over artery conduit alone, and exhibited accelerated muscle atrophy rescue. Our results demonstrated that xenographic artery conduits promoted excellent axonal regeneration with highly promising clinical relevance. PMID:23532671

  10. Numerical study of groundwater flow cycling controlled by seawater/freshwater interaction in a coastal karst aquifer through conduit network using CFPv2.

    PubMed

    Xu, Zexuan; Hu, Bill X; Davis, Hal; Kish, Stephen

    2015-11-01

    In this study, a groundwater flow cycling in a karst springshed and an interaction between two springs, Spring Creek Springs and Wakulla Springs, through a subground conduit network are numerically simulated using CFPv2, the latest research version of MODFLOW-CFP (Conduit Flow Process). The Spring Creek Springs and Wakulla Springs, located in a marine estuary and 11 miles inland, respectively, are two major groundwater discharge spots in the Woodville Karst Plain (WKP), North Florida, USA. A three-phase conceptual model of groundwater flow cycling between the two springs and surface water recharge from a major surface creek (Lost Creek) was proposed in various rainfall conditions. A high permeable subground karst conduit network connecting the two springs was found by tracer tests and cave diving. Flow rate of discharge, salinity, sea level and tide height at Spring Creek Springs could significantly affect groundwater discharge and water stage at Wakulla Springs simultaneously. Based on the conceptual model, a numerical hybrid discrete-continuum groundwater flow model is developed using CFPv2 and calibrated by field measurements. Non-laminar flows in conduits and flow exchange between conduits and porous medium are implemented in the hybrid coupling numerical model. Time-variable salinity and equivalent freshwater head boundary conditions at the submarine spring as well as changing recharges have significant impacts on seawater/freshwater interaction and springs' discharges. The developed numerical model is used to simulate the dynamic hydrological process and quantitatively represent the three-phase conceptual model from June 2007 to June 2010. Simulated results of two springs' discharges match reasonably well to measurements with correlation coefficients 0.891 and 0.866 at Spring Creeks Springs and Wakulla Springs, respectively. The impacts of sea level rise on regional groundwater flow field and relationship between the inland springs and submarine springs are

  11. Numerical study of groundwater flow cycling controlled by seawater/freshwater interaction in a coastal karst aquifer through conduit network using CFPv2

    NASA Astrophysics Data System (ADS)

    Xu, Zexuan; Hu, Bill X.; Davis, Hal; Kish, Stephen

    2015-11-01

    In this study, a groundwater flow cycling in a karst springshed and an interaction between two springs, Spring Creek Springs and Wakulla Springs, through a subground conduit network are numerically simulated using CFPv2, the latest research version of MODFLOW-CFP (Conduit Flow Process). The Spring Creek Springs and Wakulla Springs, located in a marine estuary and 11 miles inland, respectively, are two major groundwater discharge spots in the Woodville Karst Plain (WKP), North Florida, USA. A three-phase conceptual model of groundwater flow cycling between the two springs and surface water recharge from a major surface creek (Lost Creek) was proposed in various rainfall conditions. A high permeable subground karst conduit network connecting the two springs was found by tracer tests and cave diving. Flow rate of discharge, salinity, sea level and tide height at Spring Creek Springs could significantly affect groundwater discharge and water stage at Wakulla Springs simultaneously. Based on the conceptual model, a numerical hybrid discrete-continuum groundwater flow model is developed using CFPv2 and calibrated by field measurements. Non-laminar flows in conduits and flow exchange between conduits and porous medium are implemented in the hybrid coupling numerical model. Time-variable salinity and equivalent freshwater head boundary conditions at the submarine spring as well as changing recharges have significant impacts on seawater/freshwater interaction and springs' discharges. The developed numerical model is used to simulate the dynamic hydrological process and quantitatively represent the three-phase conceptual model from June 2007 to June 2010. Simulated results of two springs' discharges match reasonably well to measurements with correlation coefficients 0.891 and 0.866 at Spring Creeks Springs and Wakulla Springs, respectively. The impacts of sea level rise on regional groundwater flow field and relationship between the inland springs and submarine springs are

  12. Synergistic effects of micropatterned biodegradable conduits and Schwann cells on sciatic nerve regeneration

    NASA Astrophysics Data System (ADS)

    Rutkowski, Gregory E.; Miller, Cheryl A.; Jeftinija, Srdija; Mallapragada, Surya K.

    2004-09-01

    This paper describes a novel biodegradable conduit that provides a combination of physical, chemical and biological cues at the cellular level to facilitate peripheral nerve regeneration. The conduit consists of a porous poly(D,L-lactic acid) (PDLLA) tubular support structure with a micropatterned inner lumen. Schwann cells were pre-seeded into the lumen to provide additional trophic support. Conduits with micropatterned inner lumens pre-seeded with Schwann cells (MS) were fabricated and compared with three types of conduits used as controls: M (conduits with micropatterned inner lumens without pre-seeded Schwann cells), NS (conduits without micropatterned inner lumens pre-seeded with Schwann cells) and N (conduits without micropatterned inner lumens, without pre-seeded Schwann cells). The conduits were implanted in rats with 1 cm sciatic nerve transections and the regeneration and functional recovery were compared in the four different cases. The number or size of regenerated axons did not vary significantly among the different conduits. The time of recovery, and the sciatic function index, however, were significantly enhanced using the MS conduits, based on qualitative observations as well as quantitative measurements using walking track analysis. This demonstrates that biodegradable micropatterned conduits pre-seeded with Schwann cells that provide a combination of physical, chemical and biological guidance cues for regenerating axons at the cellular level offer a better alternative for repairing sciatic nerve transactions than conventional biodegradable conduits.

  13. Nanofibrous nerve conduit-enhanced peripheral nerve regeneration.

    PubMed

    Jiang, Xu; Mi, Ruifa; Hoke, Ahmet; Chew, Sing Yian

    2014-05-01

    Fibre structures represent a potential class of materials for the formation of synthetic nerve conduits due to their biomimicking architecture. Although the advantages of fibres in enhancing nerve regeneration have been demonstrated, in vivo evaluation of fibre size effect on nerve regeneration remains limited. In this study, we analyzed the effects of fibre diameter of electrospun conduits on peripheral nerve regeneration across a 15-mm critical defect gap in a rat sciatic nerve injury model. By using an electrospinning technique, fibrous conduits comprised of aligned electrospun poly (ε-caprolactone) (PCL) microfibers (981 ± 83 nm, Microfiber) or nanofibers (251 ± 32 nm, Nanofiber) were obtained. At three months post implantation, axons regenerated across the defect gap in all animals that received fibrous conduits. In contrast, complete nerve regeneration was not observed in the control group that received empty, non-porous PCL film conduits (Film). Nanofiber conduits resulted in significantly higher total number of myelinated axons and thicker myelin sheaths compared to Microfiber and Film conduits. Retrograde labeling revealed a significant increase in number of regenerated dorsal root ganglion sensory neurons in the presence of Nanofiber conduits (1.93 ± 0.71 × 10(3) vs. 0.98 ± 0.30 × 10(3) in Microfiber, p < 0.01). In addition, the compound muscle action potential (CMAP) amplitudes were higher and distal motor latency values were lower in the Nanofiber conduit group compared to the Microfiber group. This study demonstrated the impact of fibre size on peripheral nerve regeneration. These results could provide useful insights for future nerve guide designs.

  14. Overcoming challenges integrating patient-generated data into the clinical EHR: lessons from the CONtrolling Disease Using Inexpensive IT--Hypertension in Diabetes (CONDUIT-HID) Project.

    PubMed

    Marquard, Jenna L; Garber, Lawrence; Saver, Barry; Amster, Brian; Kelleher, Michael; Preusse, Peggy

    2013-10-01

    The CONDUIT-HID intervention integrates patients' electronic blood pressure measurements directly into the clinical EHR using Microsoft HealthVault as an intermediary data store. The goal of this paper is to describe generalizable categories of patient and technical challenges encountered in the development and implementation of this inexpensive, commercial off-the-shelf consumer health informatics intervention, examples of challenges within each category, and how the example challenges were resolved prior to conducting an RCT of the intervention. The research team logged all challenges and mediation strategies during the technical development of the intervention, conducted home visits to observe patients using the intervention, and conducted telephone calls with patients to understand challenges they encountered. We then used these data to iteratively refine the intervention. The research team identified a variety of generalizable categories of challenges associated with patients uploading data from their homes, patients uploading data from clinics because they did not have or were not comfortable using home computers, and patients establishing the connection between HealthVault and the clinical EHR. Specific challenges within these categories arose because: (1) the research team had little control over the device and application design, (2) multiple vendors needed to coordinate their actions and design changes, (3) the intervention use cases were not anticipated by the device and application designers, (4) PHI accessed on clinic computers needed to be kept secure, (5) the research team wanted the data in the clinical EHR to be valid and reliable, (6) patients needed the ability to share only the data they wanted, and (7) the development of some EHR functionalities were new to the organization. While these challenges were varied and complex, the research team was able to successfully resolve each one prior to the start of the RCT. By identifying these

  15. Neurotrophin releasing single and multiple lumen nerve conduits.

    PubMed

    Yang, Yang; De Laporte, Laura; Rives, Christopher B; Jang, Jae-Hyung; Lin, Wei-Chun; Shull, Kenneth R; Shea, Lonnie D

    2005-06-02

    Tissue engineering strategies for nerve repair employ polymer conduits termed guidance channels and bridges to promote regeneration for peripheral nerve injury and spinal cord injury, respectively. An approach for fabrication of nerve conduits with single and multiple lumens capable of controlled release of neurotrophic factors was developed. These conduits were fabricated from a mixture of poly(lactide-co-glycolide) (PLG) microspheres and porogen (NaCl) that was loaded into a mold and processed by gas foaming. The porosity and mechanical properties of the constructs were regulated by the ratio of porogen to polymer microsphere. The neurotrophin, nerve growth factor (NGF), was incorporated into the conduit by either mixing the protein with microspheres or encapsulating the protein within microspheres prior to gas foaming. A sustained release was observed for at least 42 days, with the release rate controlled by method of incorporation and polymer molecular weight. Released NGF retained its bioactivity, as demonstrated by its ability to stimulate neurite outgrowth from primary dorsal root ganglion (DRG). In vivo results indicate that conduits retain their original architecture, and allow for cellular infiltration into the channels. Polymer conduits with controllable lumen diameters and protein release may enhance nerve regeneration by guiding and stimulating neurite outgrowth.

  16. Peripheral nerve conduits: technology update

    PubMed Central

    Arslantunali, D; Dursun, T; Yucel, D; Hasirci, N; Hasirci, V

    2014-01-01

    Peripheral nerve injury is a worldwide clinical problem which could lead to loss of neuronal communication along sensory and motor nerves between the central nervous system (CNS) and the peripheral organs and impairs the quality of life of a patient. The primary requirement for the treatment of complete lesions is a tension-free, end-to-end repair. When end-to-end repair is not possible, peripheral nerve grafts or nerve conduits are used. The limited availability of autografts, and drawbacks of the allografts and xenografts like immunological reactions, forced the researchers to investigate and develop alternative approaches, mainly nerve conduits. In this review, recent information on the various types of conduit materials (made of biological and synthetic polymers) and designs (tubular, fibrous, and matrix type) are being presented. PMID:25489251

  17. Conduit properties and karstification in the unconfined Floridan aquifer.

    PubMed

    Screaton, Elizabeth; Martin, Jonathan B; Ginn, Brian; Smith, Lauren

    2004-01-01

    Exchange of water between conduits and matrix is an important control on regional chemical compositions, karstification, and quality of ground water resources in karst aquifers. A sinking stream (Santa Fe River Sink) and its resurgence (River Rise) in the unconfined portion of the Floridan Aquifer provide the opportunity to monitor conduit inflow and outflow. The use of temperature as a tracer allows determination of residence times and velocities through the conduit system. Based on temperature records from two high water events, flow is reasonably represented as pipe flow with a cross-sectional area of 380 m2, although this model may be complicated by losses of water from the conduit system at higher discharge rates. Over the course of the study year, the River Rise discharged a total of 1.9 x 10(7) m3 more water than entered the River Sink, reflecting net contribution of ground water from the matrix into the conduit system. However, as River Sink discharge rates peaked following three rainfall events during the study period, the conduit system lost water, presumably into the matrix. Surface water in high flow events is typically undersaturated with respect to calcite and thus may lead to dissolution, depending on its residence time in the matrix. A calculation of local denudation is larger than other regional estimates, perhaps reflecting return of water to conduits before calcite equilibrium is reached. The exchange of matrix and conduit water is an important variable in karst hydrology that should be considered in management of these water resources.

  18. [The preparation and evaluation of tissue inducible nerve guide conduit].

    PubMed

    Zhao, Hongbin; Liu, Xingyan; Ge, Baofeng; Guo, Chao; Zhen, Ping

    2012-04-01

    The objective of this research was to fabricate a novel tissue inducible nerve guide conduit, and to evaluate its biologic property. The microspheres were prepared with chitosan that encapsulated ligustrazine. The drug release of the chitosan microspheres was detected with application of the controlled release method in vitro. Chitosan microspheres were mixed with collagen to fabricate the tissue inducible nerve conduit, which were crosslinked with 2% genipin for 24h. Mechanical properties of the nerve guide conduit samples, including maximum load and breaking load, were measured using an Instron Series IX Automated Materials Testing System. The flexibility of the nerve guide conduit was determined with the texture evaluation instrument. Different methods, such as scanning electron microscope (SEM), light microscope (LMS) and immunofluorescence were used to analyze the spatial structure of the nerve guide conduit, the distribution of the microspheres, the state of the nerve duct combined with mesenchymal stem cells (MSCs), and the effect of the ligustrazine that released from chitosan microsphere on MSCs differentiation into nerve cells, respectively. The results showed that the chitosan microspheres had better releasing effect. The mechanical properties resultant nerve guide conduit were determined. The maximum load and breaking load of the genipin crosslinked samples were significantly higher than that observed with the non-crosslinkers, increasing to (0.76 +/- 0.15) N and (0.69 +/- 0.17) N from (0.23 +/- 0.09) N and (0.20 +/- 0.12) N for the non-crosslinkers (P < 0.01). The degradation rates of non-crosslinked and crosslinked by genipin were(58.62 +/- 7.59) mg and (9.23 +/- 2.47) mg, respec- tively. This had a statistical significance (P < 0.01). The average linearities in dry and hygrometric state of the nerve guide conduit were (0.597 +/- 0.012) LC and (0.333 +/- 0.015) LC, respectively, which also had statistical significance (P < 0.01). The flexibility in

  19. Further Development, Support and Enhancement of CONDUIT

    NASA Technical Reports Server (NTRS)

    Veronica, Moldoveanu; Levine, William S.

    1999-01-01

    From the first airplanes steered by handles, wheels, and pedals to today's advanced aircraft, there has been a century of revolutionary inventions, all of them contributing to flight quality. The stability and controllability of aircraft as they appear to a pilot are called flying or handling qualities. Many years after the first airplanes flew, flying qualities were identified and ranked from desirable to unsatisfactory. Later on engineers developed design methods to satisfy these practical criteria. CONDUIT, which stands for Control Designer's Unified Interface, is a modern software package that provides a methodology for optimization of flight control systems in order to improve the flying qualities. CONDUIT is dependent on an the optimization engine called CONSOL-OPTCAD (C-O). C-O performs multicriterion parametric optimization. C-O was successfully tested on a variety of control problems. The optimization-based computational system, C-O, requires a particular control system description as a MATLAB file and possesses the ability to modify the vector of design parameters in an attempt to satisfy performance objectives and constraints specified by the designer, in a C-type file. After the first optimization attempts on the UH-60A control system, an early interface system, named GIFCORCODE (Graphical Interface for CONSOL-OPTCAD for Rotorcraft Controller Design) was created.

  20. The influence of nerve conduits diameter in motor nerve recovery after segmental nerve repair.

    PubMed

    Giusti, Guilherme; Shin, Richard H; Lee, Joo-Yup; Mattar, Tiago G; Bishop, Allen T; Shin, Alexander Y

    2014-11-01

    Many conduits have demonstrated potential to substitute nerve autografts; however, the influence of conduit inner diameter (ID) has never been studied as a separate parameter. This experimental study compared motor recovery after segmental nerve repair with two different ID collagen conduits: 1.5 and 2.0 mm. In addition, the conduits were analyzed in vitro to determine the variations of ID before and after hydration. Thirty rats were divided into three groups: 2.0 mm ID, 1.5 mm ID, and a control group autograft. After 12 weeks, the 1.5 mm ID group demonstrated significant increase in force (P < 0.0001) and weight (P < 0.0001) of the tibialis anterior muscle and better histomorphometry results of the peroneal nerve (P < 0.05) compared to 2.0 mm ID group; nevertheless, autograft results outperformed both conduits (P < 0.0001). Conduits ID were somewhat smaller than advertised, measuring 1.59 ± 0.03 mm and 1.25 ± 0.0 mm. Only the larger conduit showed a 6% increase in ID after hydration, changing to 1.69 ± 0.02 mm. Although autografts perform best, an improvement in motor recovery can be achieved with collagen conduits when a better size match conduit is being used. Minimal changes in collagen conduits ID can be expected after implantation.

  1. Gas slug ascent through rheologically stratified conduits

    NASA Astrophysics Data System (ADS)

    Capponi, Antonio; James, Mike R.; Lane, Steve J.

    2016-04-01

    Textural and petrological evidence has indicated the presence of viscous, degassed magma layers at the top of the conduit at Stromboli. This layer acts as a plug through which gas slugs burst and it is thought to have a role in controlling the eruptive dynamics. Here, we present the results of laboratory experiments which detail the range of slug flow configurations that can develop in a rheologically stratified conduit. A gas slug can burst (1) after being fully accommodated within the plug volume, (2) whilst its base is still in the underlying low-viscosity liquid or (3) within a low-viscosity layer dynamically emplaced above the plug during the slug ascent. We illustrate the relevance of the same flow configurations at volcanic-scale through a new experimentally-validated 1D model and 3D computational fluid dynamic simulations. Applied to Stromboli, our results show that gas volume, plug thickness, plug viscosity and conduit radius control the transition between each configuration; in contrast, the configuration distribution seems insensitive to the viscosity of magma beneath the plug, which acts mainly to deliver the slug into the plug. Each identified flow configuration encompasses a variety of processes including dynamic narrowing and widening of the conduit, generation of instabilities along the falling liquid film, transient blockages of the slug path and slug break-up. All these complexities, in turn, lead to variations in the slug overpressure, mirrored by changes in infrasonic signatures which are also associated to different eruptive styles. Acoustic amplitudes are strongly dependent on the flow configuration in which the slugs burst, with both acoustic peak amplitudes and waveform shapes reflecting different burst dynamics. When compared to infrasonic signals from Stromboli, the similarity between real signals and laboratory waveforms suggests that the burst of a slug through a plug may represent a viable first-order mechanism for the generation of

  2. Peripheral facial nerve regeneration using collagen conduit entubulation in a cat model.

    PubMed

    Dresner, Harley S; King, Timothy A; Clark, H Brent; Juhn, Steven K; Levine, Samuel C

    2006-08-01

    Facial nerve (FN) injuries are functionally, psychologically, and financially debilitating. Facial nerve autograft repairs produce significant donor nerve morbidity and functional results that rarely exceed House-Brackmann (HB) grade III over VI. In this study we sought to enhance FN regeneration via collagen conduit entubulation. Five control cats underwent right ("cut-side") FN transection and immediate microsurgical anastomosis repair. Five experimental cats underwent identical repairs plus collagen conduit entubulation of each anastomosis. Postoperative behavioral observations revealed gradual FN functional recovery in all cats, who attained adapted HB grades of II to III over VI after 6 weeks. Electromyographic latencies and amplitudes from the bilateral orbicularis oculi and orbicularis oris muscles indicated restoration of FN continuity in all 10 cats. In comparison with FN repairs without conduits, repairs with conduits significantly enhanced recovery of amplitude in cut-side orbicularis oculi muscles (p = .037) and latency in cut-side orbicularis oris muscles (p = .048). In comparison with intact left ("uncut-side") FN latencies and amplitudes, more statistically significant differences in cut-side FN function were observed in repairs without conduits than in repairs with conduits. Conduits therefore facilitated a more complete return of electrophysiological function. Histologic analyses confirmed FN continuity and revealed more organized FN regenerative architecture in conduit-implanted repairs. The overall results support enhanced FN regeneration with collagen conduit entubulation.

  3. Method and apparatus for inspecting conduits

    DOEpatents

    Spisak, Michael J.; Nance, Roy A.

    1997-01-01

    An apparatus and method for ultrasonic inspection of a conduit are provided. The method involves directing a first ultrasonic pulse at a particular area of the conduit at a first angle, receiving the reflected sound from the first ultrasonic pulse, substantially simultaneously or subsequently in very close time proximity directing a second ultrasonic pulse at said area of the conduit from a substantially different angle than said first angle, receiving the reflected sound from the second ultrasonic pulse, and comparing the received sounds to determine if there is a defect in that area of the conduit. The apparatus of the invention is suitable for carrying out the above-described method. The method and apparatus of the present invention provide the ability to distinguish between sounds reflected by defects in a conduit and sounds reflected by harmless deposits associated with the conduit.

  4. 32. ISOMETRIC VIEW OF PIPING PLAN, SHOWING PATH OF CONDUIT ...

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

    32. ISOMETRIC VIEW OF PIPING PLAN, SHOWING PATH OF CONDUIT FROM CONTROL BUNKER TO SHIELDING TANK. F.C. TORKELSON DRAWING NUMBER 842-ARVFS-701-P-1. INEL INDEX CODE NUMBER: 075 0701 60 851 151977. - Idaho National Engineering Laboratory, Advanced Reentry Vehicle Fusing System, Scoville, Butte County, ID

  5. Nonlinear wavetrains in viscous conduits

    NASA Astrophysics Data System (ADS)

    Maiden, Michelle; Hoefer, Mark

    2016-11-01

    Viscous fluid conduits provide an ideal system for the study of dissipationless, dispersive hydrodynamics. A dense, viscous fluid serves as the background medium through which a lighter, less viscous fluid buoyantly rises. If the interior fluid is continuously injected, a deformable pipe forms. The long wave interfacial dynamics are well-described by a dispersive nonlinear partial differential equation. In this talk, experiments, numerics, and asymptotics of the viscous fluid conduit system will be presented. Structures at multiple length scales are discussed, including solitons, dispersive shock waves, and periodic waves. Modulations of periodic waves will be explored in the weakly nonlinear regime with the Nonlinear Schrödinger (NLS) equation. Modulational instability (stability) is identified for sufficiently short (long) periodic waves due to a change in dispersion curvature. These asymptotic results are confirmed by numerical simulations of perturbed nonlinear periodic wave solutions. Also, numerically observed are envelope bright and dark solitons well approximated by NLS. This work was partially supported by NSF CAREER DMS-1255422 (M.A.H.) and NSF GRFP (M.D.M.).

  6. Understanding Volcanic Conduit Dynamics: from Experimental Fragmentation to Volcanic Eruptions

    NASA Astrophysics Data System (ADS)

    Arciniega-Ceballos, A.; Alatorre-Ibarguengoitia, M. A.; Scheu, B.; Dingwell, D. B.

    2011-12-01

    The investigation of conduit dynamics at high pressure, under controlled laboratory conditions is a powerful tool to understand the physics behind volcanic processes before an eruption. In this work, we analyze the characteristics of the seismic response of an "experimental volcano" focusing on the dynamics of the conduit behavior during the fragmentation process of volcanic rocks. The "experimental volcano" is represented by a shock tube apparatus, which consists of a low-pressure voluminous tank (3 x 0.40 m), for sample recovery; and a high-pressure pipe-like conduit (16.5 x 2,5 cm), which represents the volcanic source mechanism, where rock samples are pressurized and fragmented. These two serial steel pipes are connected and sealed by a set of diaphragms that bear pressures in a range of 4 to 20 MPa. The history of the overall process of an explosion consists of four steps: 1) the slow pressurization of the pipe-like conduit filled with solid pumice and gas, 2) the sudden removal of the diaphragms, 3) the rapid decompression of the system and 4) the ejection of the gas-particle mixture. Each step imprints distinctive features on the microseismic records, reflecting the conduit dynamics during the explosion. In this work we show how features such as waveform characteristics, the three components of the force system acting on the conduit, the independent components of the moment tensor, the volumetric change of the source mechanism, the arrival time of the shock wave and its velocity, are quantified from the experimental microseismic data. Knowing these features, each step of the eruptive process, the conduit conditions and the source mechanism characteristics can be determined. The procedure applied in this experimental approach allows the use of seismic field data to estimate volcanic conduit conditions before an eruption takes place. We state on the hypothesis that the physics behind the pressurization and depressurization process of any conduit is the same

  7. An integrated model of magma chamber, conduit and column for the analysis of sustained explosive eruptions

    NASA Astrophysics Data System (ADS)

    Colucci, S.; de'Michieli Vitturi, M.; Neri, A.; Palladino, D. M.

    2014-10-01

    Explosive volcanic eruptions comprise a complex series of processes involving withdrawal from the magma chamber, magma ascent along the conduit and eruption column dynamics. Numerous studies have modeled the different sub-domains of a volcanic system, but their interplay has seldom been analyzed. To this end, we developed C3 (C-cubed, that stands for Chamber, Conduit and Column), a new integrated model that describes the dynamics of an explosive eruption as a series of steady state regimes and as a function of geometry and initial conditions of the magma reservoir. We used Global Sensitivity Analysis to quantify the role of the relevant model parameters and describe the interplay between the different volcanic sub-domains. In particular, we analyzed the evolution of a sustained explosive eruption in order to identify the conditions for buoyant, super-buoyant and collapsing columns. Input data were based on field reconstructions of Quaternary explosive eruptions in the Vulsini Volcanic District (Roman Province, central Italy). Model results show that: 1) the column regime, although affected by complex interactions among several factors, mostly depends on the conduit radius, the volatile content (i.e. supersaturation concentration at the top of the chamber) and length of the conduit, in decreasing level of importance; 2) the amount of mass erupted is independent of the conduit radius and depends mostly on volatile supersaturation, the radius of the magma chamber, the length of the conduit and the overpressure at the conduit inlet; 3) the mass flow-rate, column height and duration of the eruption are largely controlled by the conduit radius; 4) the flow pressure and density at the conduit exit are mostly controlled by the conduit inlet overpressure at the onset of the eruption, and by the length of the conduit at the end of the eruption; 5) the exit velocity from the conduit is mostly controlled by the volatile content, the length of the conduit and the inlet

  8. Electrical Conduit Distributes Weld Gas Evenly

    NASA Technical Reports Server (NTRS)

    Ambrisco, D. P.

    1983-01-01

    Purge-gas distributor, made from flexible electrical conduit by drilling small holes along its length, provides even gas flow for welding. Flexible conduit adjusts to accomodate almost any shape and is used for gas coverage in other applications that previously needed formed and drilled solid tubing.

  9. Conduit options in coronary artery bypass surgery.

    PubMed

    Canver, C C

    1995-10-01

    The choice of graft conduit is crucial to the success of coronary artery bypass grafting (CABG) because the patency of a coronary conduit is closely associated with an uneventful postoperative course and a better long-term patient survival. The standard conduits used for CABG are the greater saphenous vein (GSV) and the internal thoracic artery (ITA). An excellent substitute conduit for coronary bypass operations that can be taken "off the shelf" is certainly the dream of every practicing cardiac surgeon. However, virtually every synthetic and biologic alternative to arterial conduits or autologous fresh saphenous vein has proved disappointing. Fortunately, patients with absolutely no autologous conduit alternatives are uncommon. Circumstances exist, however, that often necessitate the use of alternative conduits such as young hyperlipemic patients, absent or unsuitable autologous ITAs and GSV as a result of previous myocardial revascularization, peripheral arterial reconstruction, and varicose vein ligation procedures. This review provides an update on the clinical work done with all coronary conduits available for myocardial surgical revascularization.

  10. Device and method for measuring multi-phase fluid flow in a conduit using an elbow flow meter

    DOEpatents

    Ortiz, M.G.; Boucher, T.J.

    1997-06-24

    A system is described for measuring fluid flow in a conduit. The system utilizes pressure transducers disposed generally in line upstream and downstream of the flow of fluid in a bend in the conduit. Data from the pressure transducers is transmitted to a microprocessor or computer. The pressure differential measured by the pressure transducers is then used to calculate the fluid flow rate in the conduit. Control signals may then be generated by the microprocessor or computer to control flow, total fluid dispersed, (in, for example, an irrigation system), area of dispersal or other desired effect based on the fluid flow in the conduit. 2 figs.

  11. Device and method for measuring multi-phase fluid flow in a conduit using an elbow flow meter

    DOEpatents

    Ortiz, Marcos G.; Boucher, Timothy J.

    1997-01-01

    A system for measuring fluid flow in a conduit. The system utilizes pressure transducers disposed generally in line upstream and downstream of the flow of fluid in a bend in the conduit. Data from the pressure transducers is transmitted to a microprocessor or computer. The pressure differential measured by the pressure transducers is then used to calculate the fluid flow rate in the conduit. Control signals may then be generated by the microprocessor or computer to control flow, total fluid dispersed, (in, for example, an irrigation system), area of dispersal or other desired effect based on the fluid flow in the conduit.

  12. A new nerve guide conduit material composed of a biodegradable poly(phosphoester).

    PubMed

    Wang, S; Wan, A C; Xu, X; Gao, S; Mao, H Q; Leong, K W; Yu, H

    2001-05-01

    conduits can be effective aids for nerve regeneration with potential to be further developed into more sophisticated NGCs that have better control of the conduit micro-environment for improved nerve regeneration.

  13. Engineering a multimodal nerve conduit for repair of injured peripheral nerve

    NASA Astrophysics Data System (ADS)

    Quigley, A. F.; Bulluss, K. J.; Kyratzis, I. L. B.; Gilmore, K.; Mysore, T.; Schirmer, K. S. U.; Kennedy, E. L.; O'Shea, M.; Truong, Y. B.; Edwards, S. L.; Peeters, G.; Herwig, P.; Razal, J. M.; Campbell, T. E.; Lowes, K. N.; Higgins, M. J.; Moulton, S. E.; Murphy, M. A.; Cook, M. J.; Clark, G. M.; Wallace, G. G.; Kapsa, R. M. I.

    2013-02-01

    Injury to nerve tissue in the peripheral nervous system (PNS) results in long-term impairment of limb function, dysaesthesia and pain, often with associated psychological effects. Whilst minor injuries can be left to regenerate without intervention and short gaps up to 2 cm can be sutured, larger or more severe injuries commonly require autogenous nerve grafts harvested from elsewhere in the body (usually sensory nerves). Functional recovery is often suboptimal and associated with loss of sensation from the tissue innervated by the harvested nerve. The challenges that persist with nerve repair have resulted in development of nerve guides or conduits from non-neural biological tissues and various polymers to improve the prognosis for the repair of damaged nerves in the PNS. This study describes the design and fabrication of a multimodal controlled pore size nerve regeneration conduit using polylactic acid (PLA) and (PLA):poly(lactic-co-glycolic) acid (PLGA) fibers within a neurotrophin-enriched alginate hydrogel. The nerve repair conduit design consists of two types of PLGA fibers selected specifically for promotion of axonal outgrowth and Schwann cell growth (75:25 for axons; 85:15 for Schwann cells). These aligned fibers are contained within the lumen of a knitted PLA sheath coated with electrospun PLA nanofibers to control pore size. The PLGA guidance fibers within the nerve repair conduit lumen are supported within an alginate hydrogel impregnated with neurotrophic factors (NT-3 or BDNF with LIF, SMDF and MGF-1) to provide neuroprotection, stimulation of axonal growth and Schwann cell migration. The conduit was used to promote repair of transected sciatic nerve in rats over a period of 4 weeks. Over this period, it was observed that over-grooming and self-mutilation (autotomy) of the limb implanted with the conduit was significantly reduced in rats implanted with the full-configuration conduit compared to rats implanted with conduits containing only an alginate

  14. Stochastic simulation of karst conduit networks

    NASA Astrophysics Data System (ADS)

    Pardo-Igúzquiza, Eulogio; Dowd, Peter A.; Xu, Chaoshui; Durán-Valsero, Juan José

    2012-01-01

    Karst aquifers have very high spatial heterogeneity. Essentially, they comprise a system of pipes (i.e., the network of conduits) superimposed on rock porosity and on a network of stratigraphic surfaces and fractures. This heterogeneity strongly influences the hydraulic behavior of the karst and it must be reproduced in any realistic numerical model of the karst system that is used as input to flow and transport modeling. However, the directly observed karst conduits are only a small part of the complete karst conduit system and knowledge of the complete conduit geometry and topology remains spatially limited and uncertain. Thus, there is a special interest in the stochastic simulation of networks of conduits that can be combined with fracture and rock porosity models to provide a realistic numerical model of the karst system. Furthermore, the simulated model may be of interest per se and other uses could be envisaged. The purpose of this paper is to present an efficient method for conditional and non-conditional stochastic simulation of karst conduit networks. The method comprises two stages: generation of conduit geometry and generation of topology. The approach adopted is a combination of a resampling method for generating conduit geometries from templates and a modified diffusion-limited aggregation method for generating the network topology. The authors show that the 3D karst conduit networks generated by the proposed method are statistically similar to observed karst conduit networks or to a hypothesized network model. The statistical similarity is in the sense of reproducing the tortuosity index of conduits, the fractal dimension of the network, the direction rose of directions, the Z-histogram and Ripley's K-function of the bifurcation points (which differs from a random allocation of those bifurcation points). The proposed method (1) is very flexible, (2) incorporates any experimental data (conditioning information) and (3) can easily be modified when

  15. Bubble Rise and Break-Up in Volcanic Conduits

    NASA Astrophysics Data System (ADS)

    Soldati, A.; Cashman, K. V.; Rust, A.; Rosi, M.

    2013-12-01

    The continual passive degassing occurring at open-vent mafic volcanoes is often punctuated by bursts of active degassing. The latter are generally thought to be the result of slug flow: large, conduit-filling bubbles periodically rising up the feeder conduit and bursting at the magma-air interface. Existing models of volcanic degassing systems make the simplifying assumption that the conduit is cylindrical; however, while this may be true at shallow levels, a flaring probably connects it to a dyke-like geometry at depth. The overall goal of this research is to assess the influence of conduit geometry on the speed and stability of bubbles rising in open-vent systems, and ultimately to devise a model to infer conduit shape from emerging bubbles size. In order to do that an analogue experimental approach was used. All of the experiments were two-phase (melt+volatiles); the analogue materials of choice were golden syrup-water mixtures ranging in viscosity from 10-1 to 104 Pa*s and air. Two experimental apparatuses were used: a bi-dimensional and a tri-dimensional one. The bi-dimensional set-up is a cell made of two flat transparent PVC plates (44x23cm) 10mm or 5mm apart (the front one having a hole at the bottom permitting bubble injection) containing a variety of parallelepipeds apt to outline different plumbing system geometries. The tri-dimensional one consists of a cylindrical tube (r=1,5cm; l=7cm) allowing bubble injection through the bottom rubber tap and terminating into a square tank (l=22cm). Results indicate that conduit geometry directly controls the slug rise velocity and the surrounding liquid descending speed, which in turn control the slug stability. Small enough bubbles simply deform as they go through the flaring, while bigger ones split into two daughter bubbles. A regime diagram has been constructed, illustrating the bubble break-up threshold dependence on the flare geometry and initial slug size, the two main controlling factors. The phenomenon of

  16. 47 CFR 32.2441 - Conduit systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... necessary in the construction of conduit plant. (b) The cost of pumping water out of manholes and of cleaning manholes and ducts in connection with construction work and the cost of permits and privileges...

  17. 47 CFR 32.2441 - Conduit systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... necessary in the construction of conduit plant. (b) The cost of pumping water out of manholes and of cleaning manholes and ducts in connection with construction work and the cost of permits and privileges...

  18. 47 CFR 32.2441 - Conduit systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... necessary in the construction of conduit plant. (b) The cost of pumping water out of manholes and of cleaning manholes and ducts in connection with construction work and the cost of permits and privileges...

  19. 47 CFR 32.2441 - Conduit systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... necessary in the construction of conduit plant. (b) The cost of pumping water out of manholes and of cleaning manholes and ducts in connection with construction work and the cost of permits and privileges...

  20. 47 CFR 32.2441 - Conduit systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... necessary in the construction of conduit plant. (b) The cost of pumping water out of manholes and of..., as appropriate. (d) The cost of pipes or other protective covering for underground drop and...

  1. Phase distribution in complex geometry conduits

    SciTech Connect

    Lahey, R.T. Jr.; Lopez de Bertodano, M.; Jones, O.C. Jr.

    1992-12-31

    Some of the most important and challenging problems in two-phase flow today have to do with the understanding and prediction of multidimensional phenomena, in particular, lateral phase distribution in both simple and complex geometry conduits. A prior review paper summarized the state-of-the-art in the understanding of phase distribution phenomena, and the ability to perform mechanistic multidimensional predictions. The purpose of this paper is to update that review, with particular emphasis on complex geometry conduit predictive capabilities.

  2. Pumped Storage and Potential Hydropower from Conduits

    SciTech Connect

    none,

    2015-02-25

    Th is Congressional Report, Pumped Storage Hydropower and Potential Hydropower from Conduits, addresses the technical flexibility that existing pumped storage facilities can provide to support intermittent renewable energy generation. This study considered potential upgrades or retrofit of these facilities, the technical potential of existing and new pumped storage facilities to provide grid reliability benefits, and the range of conduit hydropower opportunities available in the United States.

  3. [The continent colon-conduit stoma].

    PubMed

    Jonas, U; Wetzel, W; Hohenfellner, R

    1978-07-01

    A conduit occlusor is presented consisting of a tube surrounded by foam rubber and covered by a latex membrane, with a polyurethane cap attached to the other end. A valve imbedded in the cap allows voluntary urine drainage. This atraumatic, pneumatic, non-invasive occlusor device was used quite succesfully in 3 volunteers who had had a colon conduit urinary diversion. The device was well-tolerated, leakage was effectively prevented. Further experience, however, will be necessary for final evaluation.

  4. Modeling the closure of volcanic conduits with an application to Mount Vesuvius

    NASA Astrophysics Data System (ADS)

    Quareni, Francesca; Mulargia, Francesco

    1993-03-01

    The eruptive activity of a volcano is controlled by the opening and closure of conduits through which magma ascends to the surface. We develop a model to study the deformation of a cylindrical conduit surrounded by a viscoelastic cylindrical region in an infinite, elastic, homogeneous space. The viscoelastic behavior of the zone around the conduit is due to heat conduction from the hot magma, which raises the temperature beyond the brittle-ductile transition point. The effect of a tectonic regional stress which favors (compressive) or acts against (tensile) conduit closure is taken into account. Conduit closure is found to be ruled essentially by the extension of the viscoelastic region and by the ratio between its rigidity and the rigidity of the surrounding elastic medium, while tectonic stress is much less important. The model is applied to the last eruptive cycle of Mount Vesuvius. We find that an open conduit condition has been possible from 1631 to 1944, while the quiescence from 1944 on implies a closed conduit state.

  5. Collagen nerve conduits promote enhanced axonal regeneration, schwann cell association, and neovascularization compared to silicone conduits.

    PubMed

    Kemp, Stephen W P; Syed, Shahbaz; Walsh, Walsh; Zochodne, Douglas W; Midha, Rajiv

    2009-08-01

    Peripheral nerve regeneration within guidance conduits involves a critical association between regenerating axons, Schwann cells (SCs), and neovascularization. However, it is currently unknown if there is a greater association between these factors in nonpermeable versus semipermeable nerve guide conduits. We therefore examined this collaboration in both silicone- and collagen-based nerve conduits in both 5- and 10-mm-injury gaps in rat sciatic nerves. Results indicate that collagen conduits promoted enhanced axonal and SC regeneration and association when compared to silicone conduits in the shorter 5-mm-gap model. In addition, collagen tubes displayed enhanced neovascularization over silicone conduits, suggesting that these three factors are intimately related in successful peripheral nerve regeneration. At later time points (1- and 2-month analysis) in a 10-mm-gap model, collagen tubes displayed enhanced axonal regeneration, myelination, and vascularization when compared to silicone-based conduits. Results from these studies suggest that regenerating cables within collagen-based conduits are revascularized earlier and more completely, which in turn enhances peripheral nerve regeneration through these nerve guides as compared to silicone conduits.

  6. Bioactive poly(L-lactic acid) conduits seeded with Schwann cells for peripheral nerve regeneration.

    PubMed

    Evans, Gregory R D; Brandt, Keith; Katz, Steven; Chauvin, Priscilla; Otto, Lisa; Bogle, Melissa; Wang, Bao; Meszlenyi, Rudolph K; Lu, Lichun; Mikos, Antonios G; Patrick, Charles W

    2002-02-01

    This study attempted to enhance the efficacy of peripheral nerve regeneration using our previously tested poly(L-lactic acid) (PLLA) conduits by incorporating them with allogeneic Schwann cells (SCs). The SCs were harvested, cultured to obtain confluent monolayers and two concentrations (1 x 10(4) and 1 x 10(6) SC/ml) were combined with a collagen matrix (Vitrogen) and injected into the PLLA conduits. The conduits were then implanted into a 12 mm right sciatic nerve defect in rats. Three control groups were used: isografts, PLLA conduits filled with collagen alone and empty silicone tubes. The sciatic functional index (SFI) was calculated monthly through four months. At the end of second and fourth months, the gastrocnemius muscle was harvested and weighed for comparison and the graft conduit and distal nerve were harvested for histomorphologic analysis. The mean SFI demonstrated no group differences from isograft control. By four months, there was no significant difference in gastrocnemius muscle weight between the experimental groups compared to isograft controls. At four months, the distal nerve demonstrated a statistically lower number of axons mm2 for the high and low SC density groups and collagen control. The nerve fiber density was significantly lower in all of the groups compared to isograft controls by four months. The development of a "bioactive" nerve conduit using tissue engineering to replace autogenous nerve grafts offers a potential approach to improved patient care. Although equivalent nerve regeneration to autografts was not achieved, this study provides promising results for further investigation.

  7. Stability of volcanic conduits: insights from magma ascent modelling and possible consequences on eruptive dynamics

    NASA Astrophysics Data System (ADS)

    Aravena, Alvaro; de'Michieli Vitturi, Mattia; Cioni, Raffaello; Neri, Augusto

    2017-04-01

    Geological evidences of changes in volcanic conduit geometry (i.e. erosive processes) are common in the volcanic record, as revealed by the occurrence of lithic fragments in most pyroclastic deposits. However, the controlling factors of conduit enlargement mechanisms are still partially unclear, as well as the influence of conduit geometry in the eruptive dynamics. Despite physical models have been systematically used for studying volcanic conduits, their mechanical stability has been poorly addressed. In order to study the mechanical stability of volcanic conduits during explosive eruptions, we present a 1D steady-state model which considers the main processes experimented by ascending magmas, such as crystallization, drag forces, fragmentation, outgassing and degassing; and the application of the Mogi-Coulomb collapse criterion, using a set of constitutive equations for studying typical cases of rhyolitic and trachytic explosive volcanism. From our results emerge that conduit stability is mainly controlled by magma rheology and conduit dimensions. Indeed, in order to be stable, feeding conduits of rhyolitic eruptions need larger radii respect to their trachytic counterparts, which is manifested in the higher eruption rates usually observed in rhyolitic explosive eruptions, as confirmed by a small compilation of global data. Additionally, for both magma compositions, we estimated a minimum magma flux for developing stable conduits (˜3ṡ106 kg/s for trachytic magmas and ˜8ṡ107 kg/s for rhyolitic magmas), which is consistent with the unsteady character commonly observed in low-mass flux events (e.g. sub-Plinian eruptions), which would be produced by episodic collapse events of the volcanic conduit, opposite to the mainly stationary high-mass flux events (e.g. Plinian eruptions), characterized by stable conduits. For a given magma composition, a minimum radius for reaching stable conditions can be computed, as a function of inlet overpressure and water content

  8. Elastic chitosan conduits with multiple channels and well defined microstructure.

    PubMed

    Zhu, Jixiang; Xiong, Yi; Zeng, Chenguang; Qiang, Na; Quan, Daping; Wan, Jun

    2012-01-01

    Four kinds of chitosan conduits with longitudinal multi-channels and controlled internal microstructures were prepared using a special mold and a freeze-drying method. One of the conduits was fabricated from a chitosan solution (ab NC), while the other three groups were made from a pre-gelled chitosan solution using genipin as a chemical cross-linker (ab gNC), dibasic sodium phosphate as a physical cross-linker (ab pNC) or a combined ionic and covalent co-cross-linker (ab gpNC), respectively. The porosity of the chitosan conduits ranged from 88 to 90%. The gpNC showed highly interconnected and uniformly distributed pores compared to NC, the gNC and pNC. In contrast, the gNC and gpNC showed about 10% of the volume swelling ratio in 37°C PBS solution, although the gpNC scaffold's water uptake was the highest, at more than 17 times its original mass. Compressive tests showed that gpNC had significant elasticity and maintained its physical integrity even after compressing them down to 20% of their original height. The elastic modulus of gpNC reached 80 kPa, which was more than twice that of the other groups. Adhesion and proliferation of PC12 cells on chitosan gpNC scaffolds showed excellent properties by MTT and SEM observation, which indicated the potential of gpNC scaffolds for nerve tissue engineering applications.

  9. An Approach to Simulation of the Turbulent Multifield/Multiphase Dynamics of Volcanic Conduits and Plumes

    NASA Astrophysics Data System (ADS)

    Ogden, D. E.; Wohletz, K. H.; Glatzmaier, G. A.

    2004-12-01

    The shape and size of volcanic eruption conduits play a large role in determining the character of eruption phenomena. Conduits for explosive eruptions evolve with time during the eruption greatly affecting mass fluxes and the fate of degassed volatile constituents. Previous modeling has focused on compressible fluid dynamics of gas and solid particle mixtures moving within a cylindrical conduit and expanding into the atmosphere. However, it is clear that evolution of the conduit itself is influenced by the erupting mixture and the flow field of the mixture is controlled in part by the conduit. In order to address this important aspect of eruption dynamics, both compressible fluid flow and solid mechanics must be solved simultaneously. Two different three-dimensional state of the art computer codes have been developed at Los Alamos National Laboratories that are capable of simulating these dynamics together, CFDLib and SAGE. CFDLib is a compilation of well-tested computational fluid dynamics approaches suited for a wide range of fluid and solid dynamics, using well-known Marker-And-Cell (MAC) and Implicit Continuous-fluid Eulerian (ICE) techniques. SAGE employs adaptive grid Eulerian techniques to provide local areas of high resolution for dynamics of complex materials. We are benchmarking and validating these codes for geophysical application as a preliminary step toward modeling the three-dimensional dynamics of volcanic conduits.

  10. A model of bubble growth leading to xylem conduit embolism.

    PubMed

    Hölttä, T; Vesala, T; Nikinmaa, E

    2007-11-07

    The dynamics of a gas bubble inside a water conduit after a cavitation event was modeled. A distinction was made between a typical angiosperm conduit with a homogeneous pit membrane and a typical gymnosperm conduit with a torus-margo pit membrane structure. For conduits with torus-margo type pits pit membrane deflection was also modeled and pit aspiration, the displacement of the pit membrane to the low pressure side of the pit chamber, was found to be possible while the emboli was still small. Concurrent with pit aspiration, the high resistance to water flow out of the conduit through the cell walls or aspirated pits will make the embolism process slow. In case of no pit aspiration and always for conduits with homogeneous pit membranes, embolism growth is more rapid but still much slower than bubble growth in bulk water under similar water tension. The time needed for the embolism to fill a whole conduit was found to be dependent on pit and cell wall conductance, conduit radius, xylem water tension, pressure rise in adjacent conduits due to water freed from the embolising conduit, and the rigidity and structure of the pits in the case of margo-torus type pit membrane. The water pressure in the conduit hosting the bubble was found to occur almost immediately after bubble induction inside a conduit, creating a sudden tension release in the conduit, which can be detected by acoustic and ultra-acoustic monitoring of xylem cavitation.

  11. Frictional melting and stick-slip behavior in volcanic conduits

    NASA Astrophysics Data System (ADS)

    Kendrick, Jackie Evan; Lavallee, Yan; Hirose, Takehiro; di Toro, Giulio; Hornby, Adrian Jakob; Hess, Kai-Uwe; Dingwell, Donald Bruce

    2013-04-01

    Dome-building eruptions have catastrophic potential, with dome collapse leading to devastating pyroclastic flows with almost no precursory warning. During dome growth, the driving forces of the buoyant magma may be superseded by controls along conduit margins; where brittle fracture and sliding can lead to formation of lubricating cataclasite and gouge. Under extreme friction, pseudotachylyte may form at the conduit margin. Understanding the conduit margin processes is vital to understanding the continuation of an eruption and we postulate that pseudotachylyte generation could be the underlying cause of stick-slip motion and associated seismic "drumbeats", which are so commonly observed at dome-building volcanoes. This view is supported by field evidence in the form of pseudotachylytes identified in lava dome products at Soufrière Hills (Montserrat) and Mount St. Helens (USA). Both eruptions were characterised by repetitive, periodic seismicity and lava spine extrusion of highly viscous magma. High velocity rotary shear (HVR) experiments demonstrate the propensity for melting of the andesitic and dacitic material (from Soufrière Hills and Mount St. Helens respectively) at upper conduit stress conditions (<10 MPa). Starting from room temperature, frictional melting of the magmas occurs in under 1 s (<< 1 m) at 1.5 m/s (a speed that is achievable during stick-slip motion). At lower velocities melting occurs comparatively later due to dissipation of heat from the slip zone (e.g. 8-15 m at 0.1 m/s). Hence, given the ease with which melting is achieved in volcanic rocks, and considering the high ambient temperatures in volcanic conduits, frictional melting may thus be an inevitable consequence of viscous magma ascent. The shear resistance of the slip zone during the experiment is also monitored. Frictional melting induces a higher resistance to sliding than rock on rock, and viscous processes control the slip zone properties. Variable-rate HVR experiments which mimic

  12. 77 FR 22480 - Conduit Financing Arrangements; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-16

    ... Internal Revenue Service 26 CFR Part 1 RIN 1545-BH77 Conduit Financing Arrangements; Correction AGENCY... correction to final regulations (TD 9562) that were published in the Federal Register on Friday, December 9... arrangement. DATES: This correction is effective on April 16, 2012 and is applicable on December 9, 2011....

  13. 30 CFR 18.39 - Hose conduit.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Hose conduit. 18.39 Section 18.39 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design Requirements...

  14. 30 CFR 18.39 - Hose conduit.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Hose conduit. 18.39 Section 18.39 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design Requirements...

  15. 30 CFR 18.39 - Hose conduit.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Hose conduit. 18.39 Section 18.39 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design...

  16. 30 CFR 18.39 - Hose conduit.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Hose conduit. 18.39 Section 18.39 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design...

  17. 30 CFR 18.39 - Hose conduit.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Hose conduit. 18.39 Section 18.39 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design...

  18. Drill pipes and casings utilizing multi-conduit tubulars

    SciTech Connect

    Curlett, H.B.

    1989-01-24

    A seal adapted for use with a multi-conduit well tubular, or the like, is described which consists of: a plate with fluid passages, each passage corresponding to an opening of a conduit of the multiconduit tubular, and a groove on the plate around each passage; and elastomer means partially embeddable into each groove for sealing each conduit of a tubular to a corresponding conduit of another similar tubular.

  19. A polymer foam conduit seeded with Schwann cells promotes guided peripheral nerve regeneration.

    PubMed

    Hadlock, T; Sundback, C; Hunter, D; Cheney, M; Vacanti, J P

    2000-04-01

    axonal regeneration compared with autografts (n = 6). At 6 weeks, axonal regeneration was observed in the midconduit region of all five channels in each experimental animal. The cross-sectional area comprising axons relative to the open conduit cross sectional area (mean 26.3%, SD 10. 1%) compared favorably with autografts (mean 23.8%, SD 3.6%). Our methodology can be used to create polymer foam conduits containing longitudinally aligned channels, to introduce Schwann cells into them, and to implant them into surgically created neural defects. These conduits provide an environment permissive to axonal regeneration. Furthermore, this polymer foam-processing method and unique channeled architecture allows the introduction of neurotrophic factors into the conduit in a controlled fashion. Deposition of different factors into distinct regions within the conduit may be possible to promote more precisely guided neural regeneration.

  20. Influence of spontaneously occurring bursts of muscle sympathetic nerve activity on conduit artery diameter

    PubMed Central

    Fairfax, Seth T.; Padilla, Jaume; Vianna, Lauro C.; Holwerda, Seth H.; Davis, Michael J.

    2013-01-01

    Large increases in muscle sympathetic nerve activity (MSNA) can decrease the diameter of a conduit artery even in the presence of elevated blood pressure, suggesting that MSNA acts to regulate conduit artery tone. Whether this influence can be extrapolated to spontaneously occurring MSNA bursts has not been examined. Therefore, we tested the hypothesis that MSNA bursts decrease conduit artery diameter on a beat-by-beat basis during rest. Conduit artery responses were assessed in the brachial (BA), common femoral (CFA) and popliteal (PA) arteries to account for regional differences in vascular function. In 20 young men, MSNA, mean arterial pressure (MAP), conduit artery diameter, and shear rate (SR) were continuously measured during 20-min periods of supine rest. Spike-triggered averaging was used to characterize beat-by-beat changes in each variable for 15 cardiac cycles following all MSNA bursts, and a peak response was calculated. Diameter increased to a similar peak among the BA (+0.14 ± 0.02%), CFA (+0.17 ± 0.03%), and PA (+0.18 ± 0.03%) following MSNA bursts (all P < 0.05 vs. control). The diameter rise was positively associated with an increase in MAP in relation to increasing amplitude and consecutive numbers of MSNA bursts (P < 0.05). Such relationships were similar between arteries. SR changes following MSNA bursts were heterogeneous between arteries and did not appear to systematically alter diameter responses. Thus, in contrast to our hypothesis, spontaneously occurring MSNA bursts do not directly influence conduit arteries with local vasoconstriction or changes in shear, but rather induce a systemic pressor response that appears to passively increase conduit artery diameter. PMID:23832696

  1. Acoustic signal propagation characterization of conduit networks

    NASA Astrophysics Data System (ADS)

    Khan, Muhammad Safeer

    Analysis of acoustic signal propagation in conduit networks has been an important area of research in acoustics. One major aspect of analyzing conduit networks as acoustic channels is that a propagating signal suffers frequency dependent attenuation due to thermo-viscous boundary layer effects and the presence of impedance mismatches such as side branches. The signal attenuation due to side branches is strongly influenced by their numbers and dimensions such as diameter and length. Newly developed applications for condition based monitoring of underground conduit networks involve measurement of acoustic signal attenuation through tests in the field. In many cases the exact installation layout of the field measurement location may not be accessible or actual installation may differ from the documented layout. The lack of exact knowledge of numbers and lengths of side branches, therefore, introduces uncertainty in the measurements of attenuation and contributes to the random variable error between measured results and those predicted from theoretical models. There are other random processes in and around conduit networks in the field that also affect the propagation of an acoustic signal. These random processes include but are not limited to the presence of strong temperature and humidity gradients within the conduits, blockages of variable sizes and types, effects of aging such as cracks, bends, sags and holes, ambient noise variations and presence of variable layer of water. It is reasonable to consider that the random processes contributing to the error in the measured attenuation are independent and arbitrarily distributed. The error, contributed by a large number of independent sources of arbitrary probability distributions, is best described by an approximately normal probability distribution in accordance with the central limit theorem. Using an analytical approach to model the attenuating effect of each of the random variable sources can be very complex and

  2. Biodegradable fibrin conduit promotes long-term regeneration after peripheral nerve injury in adult rats.

    PubMed

    Pettersson, Jonas; Kalbermatten, Daniel; McGrath, Aleksandra; Novikova, Liudmila N

    2010-11-01

    Peripheral nerve injuries are often associated with loss of nerve tissue and require autologous nerve grafts to provide a physical substrate for axonal growth. Biosynthetic neural conduits could be an alternative treatment strategy in such injuries. The present study investigates the long-term effects of a tubular fibrin conduit on neuronal regeneration, axonal sprouting and recovery of muscle weight following peripheral nerve injury and repair in adult rats. Sciatic axotomy was performed proximally in the thigh to create a 10-mm gap between the nerve stumps. The injury gap was bridged by using a 14-mm-long fibrin glue conduit, entubulating 2 mm of the nerve stump at each end. A reversed autologous nerve graft was used as a control. The regenerative response from sensory and motor neurones was evaluated following retrograde labelling with Fast Blue fluorescent tracer. In control experiments, at 16 weeks following peripheral nerve grafting, 5184 (±574 standard error of mean (SEM)) sensory dorsal root ganglion neurones and 1001 (±37 SEM) spinal motor neurones regenerated across the distal nerve-graft interface. The fibrin conduit promoted regeneration of 60% of sensory neurones and 52% of motor neurones when compared to the control group. The total number of myelinated axons in the distal nerve stump in the fibrin-conduit group reached 86% of the control and the weight of gastrocnemius and soleus muscles recovered to 82% and 89% of the controls, respectively. The present results suggest that a tubular fibrin conduit can be used to promote neuronal regeneration following peripheral nerve injury. Copyright © 2009 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  3. Residual strains in conduit arteries.

    PubMed

    Rachev, A; Greenwald, S E

    2003-05-01

    Residual strains and stresses are those that exist in a body when all external loads are removed. Residual strains in arteries can be characterized by the opening angle of the sector-like cross-section which arises when an unloaded ring segment is radially cut. A review of experimental methods for measuring residual strains and the main results about the variation of the opening angle with arterial localization, age, smooth muscle activity, mechanical environment and certain vascular pathologies are presented and discussed. It is shown that, in addition to their well-established ability to homogenize the stress field in the arterial wall, residual strains make arteries more compliant and thereby improve their performance as elastic reservoirs and ensure more effective local control of the arterial lumen by smooth muscle cells. Finally, evidence that, in some cases, residual strains remain in arteries even after they have been cut radially is discussed.

  4. Comparison of conduits for leg revascularization.

    PubMed

    Weisel, R D; Johnston, K W; Baird, R J; Drezner, A D; Oates, T K; Lipton, I H

    1981-01-01

    The saphenous vein (SV) remains the conduit of choice for lower limb revascularization. When SV is unavailable, or unsuitable, two alternative conduits have been employed: gluteraldehydestablized human umbilical vein (HUV) and polytetrafluoroethylene (PTFE). In this study of the 218 patients who underwent lower limb revascularization, 3-year patency of 85 SV graft was 75% compared to 34% for the 66 HUV grafts and 33% for the 67 PFTE grafts. Three factors were found to independently influence patency: the indication for surgery, the site of the distal anastomosis, and the angiographic runoff. The SV group had significantly better patency than either HUV or PFTE in each of these subgroups. No consistent difference between HUV and PTFE was found. A risk score was obtained by assigning a value of 1 to 3 for each of the factors influencing patency--indication: 1 = claudication, 2 = rest pain, 3 = ischemic lesions; site: 1 = above knee (AK), 2 = below knee (BK), 3 = tibial; runoff 1 = good (two or three vessels), 2 = fair (one vessel), 3 = poor (no vessel). Patients with the lowest risk scores (3 to 4) had the best 3-year patency: SV, 78%; HUV, 44%; and PTFE, 48%. Patients with the highest risk scores (7 to 9) had the worst 3-year patency: SV, 68%; HUV, 32%; and PTFE, 28%. SVs had better patency under high- and low-risk conditions and remain the conduit of choice for lower limb revascularization. Both HUV and PTFE have equivalent and acceptable patency when SV is unavailable or unstable.

  5. High temperature lined conduits, elbows and tees

    DOEpatents

    De Feo, Angelo; Drewniany, Edward

    1982-01-01

    A high temperature lined conduit comprising, a liner, a flexible insulating refractory blanket around and in contact with the liner, a pipe member around the blanket and spaced therefrom, and castable rigid refractory material between the pipe member and the blanket. Anchors are connected to the inside diameter of the pipe and extend into the castable material. The liner includes male and female slip joint ends for permitting thermal expansion of the liner with respect to the castable material and the pipe member. Elbows and tees of the lined conduit comprise an elbow liner wrapped with insulating refractory blanket material around which is disposed a spaced elbow pipe member with castable refractory material between the blanket material and the elbow pipe member. A reinforcing band is connected to the elbow liner at an intermediate location thereon from which extend a plurality of hollow tubes or pins which extend into the castable material to anchor the lined elbow and permit thermal expansion. A method of fabricating the high temperature lined conduit, elbows and tees is also disclosed which utilizes a polyethylene layer over the refractory blanket after it has been compressed to maintain the refractory blanket in a compressed condition until the castable material is in place. Hot gases are then directed through the interior of the liner for evaporating the polyethylene and setting the castable material which permits the compressed blanket to come into close contact with the castable material.

  6. Assessment of conduit artery vasomotion using photoplethysmography

    NASA Astrophysics Data System (ADS)

    Kanders, Karlis; Grabovskis, Andris; Marcinkevics, Zbignevs; Aivars, Juris Imants

    2013-11-01

    Vasomotion is a spontaneous oscillation of vascular tone. The phenomenon has been observed in small arterioles and capillaries as well as in the large conduit arteries. The layer of smooth muscle cells that surrounds a blood vessel can spontaneously and periodically change its tension and thereby the arterial wall stiffness also changes. As the understanding of the phenomenon is still rather obscure, researchers would benefit from a low-cost and reliable investigation technique such as photoplethysmography (PPG). PPG is an optical blood pulsation measurement technique that can offer substantial information about the arterial stiffness. The aims of this pilot study were to evaluate the usefulness of the PPG technique in the research of vasomotion and to investigate vasomotion in the relatively large conduit arteries. Continuous 15 minute long measurements of posterior tibial artery wall stiffness were taken. Artery diameter, electrocardiogram, blood pressure and respiration were also simultaneously registered. Fast Fourier Transform power spectra were calculated to identify unique stiffness oscillations that did not correspond to fluctuations in the systemic parameters and thus would indicate vasomotion. We concluded that photoplethysmography is a convenient method for the research of the vasomotion in large arteries. Local stiffness parameter b/a is more accurate to use and easier to measure than the pulse wave velocity which describes stiffness of a segment of an artery. Conduit arteries might exhibit a low amplitude high frequency vasomotion ( 9 to 27 cycles per minute). Low frequency vasomotion is problematic to distinguish from the passive oscillations imposed by the arterial pressure.

  7. Inference of the structure of karst conduits using quantitative tracer tests and geological information: example of the Swiss Jura

    NASA Astrophysics Data System (ADS)

    Perrin, Jérôme; Luetscher, Marc

    2008-08-01

    Karst aquifers are known for being particularly heterogeneous with highly transmissive conduits embedded in low permeability volumes of rock matrix. Artificial tracer experiments have been carried out in a complex karst aquifer of the folded Jura Mountains in Switzerland with the aim of deciphering the conduit organisation. It is shown that tracer experiments with multiple injection points under different flow conditions can lead to useful information on the conduits’ structure. This information has been combined with data from structural geology, spring hydrology, and speleological observations. A conceptual model of the conduit network shows that a detailed inference of the conduit organisation can be reached: geology controls conduit location and orientation; spring hydrology, including temporary springs, constrains conduit elevations and relative hydraulic heads in the aquifer subsystems; and tracer tests identify major flow paths and outlets of the system and dilution caused by non-traced tributaries, as well as the presence of secondary flow routes. This understanding of the Aubonne aquifer structure has important implications for the future management of the groundwater resource. Similar approaches coupling geological information, spring hydrology, and multi-tracer tests under various flow conditions may help to characterise the structure of the conduit network in karst aquifers.

  8. DEFORMATION OF SCORIA CONE BY CONDUIT PRESSURIZATION

    SciTech Connect

    E.S. Gaffney; B. Damjanac; D. Krier; G. Valentine

    2005-08-26

    A simplified mechanical model is used to simulate the deformation of a scoria cone due to pressurization of magma in a feeder conduit. The scoria cone is modeled as consisting of a cone of stabilized scoria with an axial region of loose scoria (height h{sub 1}), all overlying a vertically oriented cylindrical conduit intruded into rhyolite tuff country rock. For our analyses, the conduit is filled with basalt magma, usually with the upper length (h{sub 2}) solidified. The style of deformation of the cone depends on both h{sub 1} and h{sub 2}. If magma is prevented from hydrofracturing out of the conduit (as, for example, might be the case if the magma is surrounded by a solidified, but plastically deformable layer acting as a gasket backed up by the brittle country rock) pressures in the magma can build to 10s of MPa. When h{sub 1} is 100 m, not unusual for a small isolated basaltic cinder cone, the magma pressure needed to destabilize the cone when molten magma extends all the way to the original ground surface (h{sub 2} = 0) is only about one-third of the pressure when the upper part of the conduit is solidified (h{sub 2} = 25m). In the former case, almost the entire upper third of the cone is at failure in tension when the configuration becomes unstable. In the latter case, small portions of the surface of the cone are failing in tension when instability occurs, but a large volume in the central core of the cone is failing in shear or compressions. These results may provide insight into the status of volcanic plumbing, either past or present, beneath scoria cones. Field observations at the Lathrop Wells volcano in southern Nevada identify structures at the outer edge just below the crater rim that appear to be inward-dipping listric normal faults. This may indicate that, near the end of its active stage, the cone was close to failing in this fashion. A companion paper suggests that such a failure could have been quite energetic had it occurred.

  9. Small scale high resolution LiDAR measurements of a subglacial conduit

    NASA Astrophysics Data System (ADS)

    Mankoff, K. D.; Gulley, J.

    2012-04-01

    We present direct measurements of surface roughness in a sub-glacial conduit system underneath the Rieperbreen Glacier, Svalbard, Norway. Data was collected with a low-cost (129 USD) Microsoft Kinect video game device used as a LIDAR sensor. Surface roughness is a primary control on water flow in rivers, channels, and cave conduit systems and understanding the effects of surface roughness on water flow has been problematic due to lack of direct measurements of roughness in natural systems. We use the ice scallop dimensions to derive flow velocity and explore implications of the changing roughness parameters as the cave grows and shrinks.

  10. System and method measuring fluid flow in a conduit

    DOEpatents

    Ortiz, M.G.; Kidd, T.G.

    1999-05-18

    A system is described for measuring fluid mass flow in a conduit in which there exists a pressure differential in the fluid between at least two spaced-apart locations in the conduit. The system includes a first pressure transducer disposed in the side of the conduit at a first location for measuring pressure of fluid at that location, a second or more pressure transducers disposed in the side of the conduit at a second location, for making multiple measurements of pressure of fluid in the conduit at that location, and a computer for computing the average pressure of the multiple measurements at the second location and for computing flow rate of fluid in the conduit from the pressure measurement by the first pressure transducer and from the average pressure calculation of the multiple measurements. 3 figs.

  11. System and method measuring fluid flow in a conduit

    DOEpatents

    Ortiz, Marcos German; Kidd, Terrel G.

    1999-01-01

    A system for measuring fluid mass flow in a conduit in which there exists a pressure differential in the fluid between at least two spaced-apart locations in the conduit. The system includes a first pressure transducer disposed in the side of the conduit at a first location for measuring pressure of fluid at that location, a second or more pressure transducers disposed in the side of the conduit at a second location, for making multiple measurements of pressure of fluid in the conduit at that location, and a computer for computing the average pressure of the multiple measurements at the second location and for computing flow rate of fluid in the conduit from the pressure measurement by the first pressure transducer and from the average pressure calculation of the multiple measurements.

  12. Conduits for Coronary Bypass: Vein Grafts

    PubMed Central

    Farkas, Emily A

    2012-01-01

    The saphenous vein has been the principal conduit for coronary bypass grafting from the beginning, circa 1970. This report briefly traces this history and concomitantly presents one surgeons experience and personal views on use of the vein graft. As such it is not exhaustive but meant to be practical with a modest number of references. The focus is that of providing guidance and perspective which may be at variance with that of others and recognizing that there may be many ways to accomplish the task at hand. Hopefully the surgeon in training/early career may find this instructive on the journey to surgical maturity. PMID:23130300

  13. Delayed complication of pelvic lymphocele: Ileal conduit obstruction.

    PubMed

    Bankar, Sanket S; Bakshi, Ganesh K; Prakash, Gagan; Sable, Nilesh P

    2015-01-01

    Radical cystectomy is the standard treatment for muscle invasive bladder cancer. Lymphocele is a common sequalae of pelvic lymphadenectomy. We report an unusual presentation of pelvic lymphocele developing after radical cystectomy reconstructed with an ileal conduit where the patient developed obstruction of the ileal conduit loop due to external pressure of the lymphocele. Catheter drainage of the conduit relieved the symptoms and a computerized tomography scan showed a large lymphocele causing acute angulation and resultant obstruction of the ileal conduit. The patient was treated with percutaneous drainage of the lymphocele and remains symptom-free on follow-up at 1 year.

  14. Delayed complication of pelvic lymphocele: Ileal conduit obstruction

    PubMed Central

    Bankar, Sanket S.; Bakshi, Ganesh K.; Prakash, Gagan; Sable, Nilesh P.

    2015-01-01

    Radical cystectomy is the standard treatment for muscle invasive bladder cancer. Lymphocele is a common sequalae of pelvic lymphadenectomy. We report an unusual presentation of pelvic lymphocele developing after radical cystectomy reconstructed with an ileal conduit where the patient developed obstruction of the ileal conduit loop due to external pressure of the lymphocele. Catheter drainage of the conduit relieved the symptoms and a computerized tomography scan showed a large lymphocele causing acute angulation and resultant obstruction of the ileal conduit. The patient was treated with percutaneous drainage of the lymphocele and remains symptom-free on follow-up at 1 year. PMID:26166973

  15. Transplantation of Autologous Minced Bladder Mucosa for a One-Step Reconstruction of a Tissue Engineered Bladder Conduit

    PubMed Central

    Reinfeldt Engberg, Gisela; Chamorro, Clara Ibel; Nordenskjöld, Agneta

    2013-01-01

    Surgical intervention is sometimes needed to create a conduit from the abdominal wall to the bladder for self-catheterization. We developed a method for tissue engineering a conduit for bladder emptying without in vitro cell culturing as a one-step procedure. In a porcine animal model bladder, wall tissue was excised and the mucosa was minced to small particles. The particles were attached to a tube in a 1 : 3 expansion rate with fibrin glue and transplanted back by attaching the tube to the bladder and through the abdominal wall. Sham served as controls. After 4-5 weeks, conduits were assessed in respect to macroscopic and microscopic appearance in 6 pigs. Two pigs underwent radiology before termination. Gross examination revealed a patent conduit with an opening to the bladder. Histology and immunostaining showed a multilayered transitional uroepithelium in all cases. Up to 89% of the luminal surface area was neoepithelialized but with a loose attachment to the submucosa. No epithelium was found in control animals. CT imaging revealed a patent channel that could be used for filling and emptying the bladder. Animals that experienced surgical complications did not form conduits. Minced autologous bladder mucosa can be transplanted around a tubular mold to create a conduit to the urinary bladder without in vitro culturing. PMID:24288669

  16. Pumice, a window into the volcanic conduit

    NASA Astrophysics Data System (ADS)

    Degruyter, W.; Dufek, J.; Bachmann, O.

    2009-12-01

    To better understand pumice microtextures and stress distribution within the volcanic conduit, a numerical study is performed using passive tracers to map the type and amount of shear in different parts of the conduit. During an explosive eruption pumices are formed by fragmenting the rising magmatic foam (i.e. highly vesicular magma). Provided they are quenched fast enough, pumices reflect the state of the magma just prior to fragmentation and their microtextures carry information on the stresses applied during magma ascent. Numerous deposits contain both tube pumice, with highly elongated vesicles and frothy pumice, with nearly spherical vesicles showing evidence that they were exposed to different stresses during magma ascent (e.g. Kos Plateau Tuff and Campanian Ignimbrite). The main aim of this investigation is to determine the strain histories of magmatic parcels that eventually become pumice We have modified the Multiphase Flow with Interphase Exchanges (MFIX) code to simulate a two-phase (bubbles and magma), two-dimensional, isothermal flow with disequilibrium bubble growth. We include a rheology model depending on water content with outlet expansion into the atmosphere. Furthermore, different fragmentation criteria (i.e. critical gas volume fraction, strain rate and gas overpressure) are examined. Strain histories are investigated by releasing passive tracers within simulated magma rise, which record the pure and simple shear strain rates during ascent. The range of accumulated stresses at fragmentation shown by the passive tracers can then be linked to the range of different microtextures found within pumices.

  17. Modeling magma flow in volcanic conduit with non-equilibrium crystallization

    NASA Astrophysics Data System (ADS)

    Yulia, Tsvetkova

    2010-05-01

    , and thus viscosity variations across the conduit are large. A more comprehensive model was developed to account for cross-conduit parameter distributions. It shows that velocity profile significantly differ from parabolic especially near the top of the conduit where slip condition s occurs. References 1. A.Barmin, O.Melnik, R.S.J.Sparks, Periodoc behavior in lava dome eruptions, Earth and Planetary Science Letters 199(2002) 173-184 2. P.M.Bruce, H.E.Huppert, Thermal control of basaltic fissure eruptions, 1989, Letters To Nature, VOL 342 3. I.Maeda, Nonlinaer visco-elastic volcanic model and its application to the recent eruption of Mt.Unzen, 2000, Journal of Volcanology and Geothermal Research, 95, 35-47 4. J.A.Whitehead, K.R.Helfrich, Instability of flow with temperature dependent viscosity: a model of magma dynamics, 1991, Journal of Geophysical Research, VOL 96, No B3, pages 4145-4155 5. A.Costa, G.Macedonio, Nonlinear phenomena in fluids with temperature-dependent viscosity: an hysteresis model for magma flow in conduits, 2002, Geophysical Research Letters, VOL 29, No 10, 1402 6. Richard Iverson Dynamics of Seismogenic Volcanic Extrusion Re¬sisted by a Solid Surface Plug, Mount St. Helens, 2004-2005, A Volcano Rekindled: The First Year of Renewed Eruption at Mount St. Helens, 2004-2006. 7. Couch, S., C. L. Harford, R. S. J. Sparks, and M. R. Carroll (2003),Experimental constraints on the conditions of formation of highly calcic plagioclase microlites at the Soufrie`re Hills Volcano, Montserrat, J. Petrol.,44, 1455- 1475.

  18. Modelling shear bands in a volcanic conduit: Implications for over-pressures and extrusion-rates

    NASA Astrophysics Data System (ADS)

    Hale, Alina J.; Mühlhaus, Hans-B.

    2007-11-01

    Shear bands in a volcanic conduit are modelled for crystal-rich magma flow using simplified conditions to capture the fundamental behaviour of a natural system. Our simulations begin with magma crystallinity in equilibrium with an applied pressure field and isothermal conditions. The viscosity of the magma is derived using existing empirical equations and is dependent upon temperature, water content and crystallinity. From these initial conduit conditions we utilize the Finite Element Method, using axi-symmetric coordinates, to simulate shear bands via shear localisation. We use the von Mises visco-plasticity model with constant magma shear strength for a first look into the effects of plasticity. The extent of shear bands in the conduit is explored with a numerical model parameterized with values appropriate for Soufrière Hills Volcano, Montserrat, although the model is generic in nature. Our model simulates shallow (up to approximately 700 m) shear bands that occur within the upper conduit and probably govern the lava extrusion style due to shear boundaries. We also model the change in the over-pressure field within the conduit for flow with and without shear bands. The pressure change can be as large as several MPa at shallow depths in the conduit, which generates a maximum change in the pressure gradient of 10's of kPa/m. The formation of shear bands could therefore provide an alternative or additional mechanism for the inflation/deflation of the volcano flanks as measured by tilt-metres. Shear bands are found to have a significant effect upon the magma ascent rate due to shear-induced flow reducing conduit friction and altering the over-pressure in the upper conduit. Since we do not model frictional controlled slip, only plastic flow, our model calculates the minimum change in extrusion rate due to shear bands. However, extrusion rates can almost double due to the formation of shear bands, which may help suppress volatile loss. Due to the paucity of data and

  19. Polyurethane/Gelatin Nanofibrils Neural Guidance Conduit Containing Platelet-Rich Plasma and Melatonin for Transplantation of Schwann Cells.

    PubMed

    Salehi, Majid; Naseri-Nosar, Mahdi; Ebrahimi-Barough, Somayeh; Nourani, Mohammdreza; Khojasteh, Arash; Farzamfar, Saeed; Mansouri, Korosh; Ai, Jafar

    2017-08-19

    The current study aimed to enhance the efficacy of peripheral nerve regeneration using a biodegradable porous neural guidance conduit as a carrier to transplant allogeneic Schwann cells (SCs). The conduit was prepared from polyurethane (PU) and gelatin nanofibrils (GNFs) using thermally induced phase separation technique and filled with melatonin (MLT) and platelet-rich plasma (PRP). The prepared conduit had the porosity of 87.17 ± 1.89%, the contact angle of 78.17 ± 5.30° and the ultimate tensile strength and Young's modulus of 5.40 ± 0.98 MPa and 3.13 ± 0.65 GPa, respectively. The conduit lost about 14% of its weight after 60 days in distilled water. The produced conduit enhanced the proliferation of SCs demonstrated by a tetrazolium salt-based assay. For functional analysis, the conduit was seeded with 1.50 × 10(4) SCs (PU/GNFs/PRP/MLT/SCs) and implanted into a 10-mm sciatic nerve defect of Wistar rat. Three control groups were used: (1) PU/GNFs/SCs, (2) PU/GNFs/PRP/SCs, and (3) Autograft. The results of sciatic functional index, hot plate latency, compound muscle action potential amplitude and latency, weight-loss percentage of wet gastrocnemius muscle and histopathological examination using hematoxylin-eosin and Luxol fast blue staining, demonstrated that using the PU/GNFs/PRP/MLT conduit to transplant SCs to the sciatic nerve defect resulted in a higher regenerative outcome than the PU/GNFs and PU/GNFs/PRP conduits.

  20. 26 CFR 1.881-3 - Conduit financing arrangements.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 9 2010-04-01 2010-04-01 false Conduit financing arrangements. 1.881-3 Section 1.881-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Foreign Corporations § 1.881-3 Conduit financing arrangements. (a) General rules and definitions—(1) Purpose and scope....

  1. Biopsy of ureteral tumor in patient with ileal conduit.

    PubMed

    Shental, J; Nussinson, E; Schmitz, A; Sudarsky, M

    1985-11-01

    A patient with ileal conduit and recent dilation of the left upper collecting system had flexible fiberoptic endoscopy of the ileal loop. The entire lumen of the intestinal conduit and the ureteroileal anastomosis were visualized. In addition retrograde pyelography and direct vision biopsy of a tumor in the ureter were performed.

  2. Engineering Bi-Layer Nanofibrous Conduits for Peripheral Nerve Regeneration

    PubMed Central

    Zhu, Yiqian; Wang, Aijun; Patel, Shyam; Kurpinski, Kyle; Diao, Edward; Bao, Xuan; Kwong, George; Young, William L.

    2011-01-01

    Trauma injuries often cause peripheral nerve damage and disability. A goal in neural tissue engineering is to develop synthetic nerve conduits for peripheral nerve regeneration having therapeutic efficacy comparable to that of autografts. Nanofibrous conduits with aligned nanofibers have been shown to promote nerve regeneration, but current fabrication methods rely on rolling a fibrous sheet into the shape of a conduit, which results in a graft with inconsistent size and a discontinuous joint or seam. In addition, the long-term effects of nanofibrous nerve conduits, in comparison with autografts, are still unknown. Here we developed a novel one-step electrospinning process and, for the first time, fabricated a seamless bi-layer nanofibrous nerve conduit: the luminal layer having longitudinally aligned nanofibers to promote nerve regeneration, and the outer layer having randomly organized nanofibers for mechanical support. Long-term in vivo studies demonstrated that bi-layer aligned nanofibrous nerve conduits were superior to random nanofibrous conduits and had comparable therapeutic effects to autografts for nerve regeneration. In summary, we showed that the engineered nanostructure had a significant impact on neural tissue regeneration in situ. The results from this study will also lead to the scalable fabrication of engineered nanofibrous nerve conduits with designed nanostructure. This technology platform can be combined with drug delivery and cell therapies for tissue engineering. PMID:21501089

  3. 26 CFR 1.7701(l)-1 - Conduit financing arrangements.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 13 2010-04-01 2010-04-01 false Conduit financing arrangements. 1.7701(l)-1 Section 1.7701(l)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES General Actuarial Valuations § 1.7701(l)-1 Conduit...

  4. 26 CFR 1.881-3 - Conduit financing arrangements.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 9 2014-04-01 2014-04-01 false Conduit financing arrangements. 1.881-3 Section 1.881-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Foreign Corporations § 1.881-3 Conduit financing arrangements. (a) General rules and definitions—(1) Purpose...

  5. 26 CFR 1.881-3 - Conduit financing arrangements.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 9 2013-04-01 2013-04-01 false Conduit financing arrangements. 1.881-3 Section 1.881-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Foreign Corporations § 1.881-3 Conduit financing arrangements. (a) General rules and definitions—(1) Purpose...

  6. 26 CFR 1.881-3 - Conduit financing arrangements.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 9 2012-04-01 2012-04-01 false Conduit financing arrangements. 1.881-3 Section 1.881-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Foreign Corporations § 1.881-3 Conduit financing arrangements. (a) General rules and definitions—(1) Purpose...

  7. Water Flow in Karst Aquifer Considering Dynamically Variable Saturation Conduit

    NASA Astrophysics Data System (ADS)

    Tan, Chaoqun; Hu, Bill X.

    2017-04-01

    The karst system is generally conceptualized as dual-porosity system, which is characterized by low conductivity and high storage continuum matrix and high conductivity and quick flow conduit networks. And so far, a common numerical model for simulating flow in karst aquifer is MODFLOW2005-CFP, which is released by USGS in 2008. However, the steady-state approach for conduit flow in CFP is physically impractical when simulating very dynamic hydraulics with variable saturation conduit. So, we adopt the method proposed by Reimann et al. (2011) to improve current model, in which Saint-Venant equations are used to model the flow in conduit. Considering the actual background that the conduit is very big and varies along flow path and the Dirichlet boundary varies with rainfall in our study area in Southwest China, we further investigate the influence of conduit diameter and outflow boundary on numerical model. And we also analyze the hydraulic process in multi-precipitation events. We find that the numerical model here corresponds well with CFP for saturated conduit, and it could depict the interaction between matrix and conduit during very dynamic hydraulics pretty well compare with CFP.

  8. 18 CFR 358.6 - No conduit rule.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false No conduit rule. 358.6 Section 358.6 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY STANDARDS OF CONDUCT FOR TRANSMISSION PROVIDERS STANDARDS OF CONDUCT § 358.6 No conduit...

  9. 18 CFR 358.6 - No conduit rule.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false No conduit rule. 358.6 Section 358.6 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY STANDARDS OF CONDUCT FOR TRANSMISSION PROVIDERS STANDARDS OF CONDUCT § 358.6 No conduit...

  10. 18 CFR 358.6 - No conduit rule.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false No conduit rule. 358.6 Section 358.6 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY STANDARDS OF CONDUCT FOR TRANSMISSION PROVIDERS STANDARDS OF CONDUCT § 358.6 No conduit...

  11. 18 CFR 358.6 - No conduit rule.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false No conduit rule. 358.6 Section 358.6 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY STANDARDS OF CONDUCT FOR TRANSMISSION PROVIDERS STANDARDS OF CONDUCT § 358.6 No conduit...

  12. 18 CFR 358.6 - No conduit rule.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false No conduit rule. 358.6 Section 358.6 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY STANDARDS OF CONDUCT FOR TRANSMISSION PROVIDERS STANDARDS OF CONDUCT § 358.6 No conduit...

  13. 26 CFR 1.7701(l)-1 - Conduit financing arrangements.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 13 2011-04-01 2011-04-01 false Conduit financing arrangements. 1.7701(l)-1 Section 1.7701(l)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) General Actuarial Valuations § 1.7701(l)-1 Conduit...

  14. 26 CFR 1.7701(l)-1 - Conduit financing arrangements.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 13 2014-04-01 2014-04-01 false Conduit financing arrangements. 1.7701(l)-1 Section 1.7701(l)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) General Actuarial Valuations § 1.7701(l)-1 Conduit...

  15. 26 CFR 1.7701(l)-1 - Conduit financing arrangements.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 13 2012-04-01 2012-04-01 false Conduit financing arrangements. 1.7701(l)-1 Section 1.7701(l)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) General Actuarial Valuations § 1.7701(l)-1 Conduit...

  16. 26 CFR 1.7701(l)-1 - Conduit financing arrangements.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 13 2013-04-01 2013-04-01 false Conduit financing arrangements. 1.7701(l)-1 Section 1.7701(l)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) General Actuarial Valuations § 1.7701(l)-1 Conduit...

  17. Viscous Fluid Conduits as a Prototypical Nonlinear Dispersive Wave Platform

    NASA Astrophysics Data System (ADS)

    Lowman, Nicholas K.

    This thesis is devoted to the comprehensive characterization of slowly modulated, nonlinear waves in dispersive media for physically-relevant systems using a threefold approach: analytical, long-time asymptotics, careful numerical simulations, and quantitative laboratory experiments. In particular, we use this interdisciplinary approach to establish a two-fluid, interfacial fluid flow setting known as viscous fluid conduits as an ideal platform for the experimental study of truly one dimensional, unidirectional solitary waves and dispersively regularized shock waves (DSWs). Starting from the full set of fluid equations for mass and linear momentum conservation, we use a multiple-scales, perturbation approach to derive a scalar, nonlinear, dispersive wave equation for the leading order interfacial dynamics of the system. Using a generalized form of the approximate model equation, we use numerical simulations and an analytical, nonlinear wave averaging technique, Whitham-El modulation theory, to derive the key physical features of interacting large amplitude solitary waves and DSWs. We then present the results of quantitative, experimental investigations into large amplitude solitary wave interactions and DSWs. Overtaking interactions of large amplitude solitary waves are shown to exhibit nearly elastic collisions and universal interaction geometries according to the Lax categories for KdV solitons, and to be in excellent agreement with the dynamics described by the approximate asymptotic model. The dispersive shock wave experiments presented here represent the most extensive comparison to date between theory and data of the key wavetrain parameters predicted by modulation theory. We observe strong agreement. Based on the work in this thesis, viscous fluid conduits provide a well-understood, controlled, table-top environment in which to study universal properties of dispersive hydrodynamics. Motivated by the study of wave propagation in the conduit system, we

  18. How to quantify conduits in wood?

    PubMed Central

    Scholz, Alexander; Klepsch, Matthias; Karimi, Zohreh; Jansen, Steven

    2013-01-01

    Vessels and tracheids represent the most important xylem cells with respect to long distance water transport in plants. Wood anatomical studies frequently provide several quantitative details of these cells, such as vessel diameter, vessel density, vessel element length, and tracheid length, while important information on the three dimensional structure of the hydraulic network is not considered. This paper aims to provide an overview of various techniques, although there is no standard protocol to quantify conduits due to high anatomical variation and a wide range of techniques available. Despite recent progress in image analysis programs and automated methods for measuring cell dimensions, density, and spatial distribution, various characters remain time-consuming and tedious. Quantification of vessels and tracheids is not only important to better understand functional adaptations of tracheary elements to environment parameters, but will also be essential for linking wood anatomy with other fields such as wood development, xylem physiology, palaeobotany, and dendrochronology. PMID:23507674

  19. How to quantify conduits in wood?

    PubMed

    Scholz, Alexander; Klepsch, Matthias; Karimi, Zohreh; Jansen, Steven

    2013-01-01

    Vessels and tracheids represent the most important xylem cells with respect to long distance water transport in plants. Wood anatomical studies frequently provide several quantitative details of these cells, such as vessel diameter, vessel density, vessel element length, and tracheid length, while important information on the three dimensional structure of the hydraulic network is not considered. This paper aims to provide an overview of various techniques, although there is no standard protocol to quantify conduits due to high anatomical variation and a wide range of techniques available. Despite recent progress in image analysis programs and automated methods for measuring cell dimensions, density, and spatial distribution, various characters remain time-consuming and tedious. Quantification of vessels and tracheids is not only important to better understand functional adaptations of tracheary elements to environment parameters, but will also be essential for linking wood anatomy with other fields such as wood development, xylem physiology, palaeobotany, and dendrochronology.

  20. Cardiac compression secondary to a massively dilated substernal colon conduit.

    PubMed

    Khan, Babar A; Ionescu, Ruxandra C; Halal, Ahmed M; Kesler, Kenneth A

    2012-11-01

    With the growing success of surgical repairs of congenital defects previously incompatible with life, it is expected of these patients to live longer and experience the complications of these corrective procedures. Esophageal atresia is a congenital defect that occurs in 1 out of 4000 births and is oftentimes a surgical emergency in which colonic conduits are routinely used for esophageal reconstruction. Colonic conduit redundancy and dilatation are well-recognized late complications of colon conduit surgeries for esophageal reconstructions. We report a rare case of symptomatic cardiac compression secondary to a massively dilated substernal colon conduit occurring 44 years after the initial childhood surgery in 1964 with rapid reversal of hemodynamic compromise after conduit removal. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Alternative Fuels Compatibility with Army Equipment Testing - Aged Niedner Rifts Conduit Testing

    DTIC Science & Technology

    2012-02-01

    ends of the conduit using IPDS couplings to attach them to the conduit end fittings. 2 Setup the plumbing for the pump to pressurize the conduit. 3...Cyclic Testing Procedure Step No. Description 1 End Plugs should be installed on both ends of the conduit using IPDS couplings to attach them to the...testing site. Pressurization Cycles 12 End Plugs should be installed on both ends of the conduit using IPDS couplings to attach them to the conduit

  2. The effect of high outflow permeability in asymmetric poly(dl-lactic acid-co-glycolic acid) conduits for peripheral nerve regeneration.

    PubMed

    Chang, Chen-Jung; Hsu, Shan-Hui

    2006-03-01

    This study attempted to accelerate the peripheral nerve regeneration, using the high outflow rate of asymmetric poly(dl-lactic acid-co-glycolic acid) (PLGA) nerve conduits. Asymmetric PLGA nerve conduits of monomer ratio 85/15 were prepared by immersion-precipitation method to serve as possible materials. In this study, mandrels were immersed into a 20% (wt/wt) of PLGA/1,4-dioxane solution and precipitated in a non-solvent bath followed by freeze-drying. Different concentrations of isopropyl alcohol (95%, 40% and 20%) were used as precipitation baths where non-asymmetric (95%) and asymmetric (40% and 20%) conduits could easily form. The asymmetric nerve conduits that consisted of macrovoids on the outer layer, and interconnected micropores in the inner sublayer, possessed characters of larger outflow rate than inflow rate. The asymmetric conduits were implanted to 10mm right sciatic nerve defects in rats. Autografts, silicone and non-asymmetric PLGA conduits were performed as the control and the contrast groups. Implanted graft specimens of all groups were harvested for histological analysis at 4 and 6 weeks following surgery. The asymmetric PLGA conduits maintained a stable supporting structure and inhibited exogenous cells invasion during entire regeneration process. Asymmetric PLGA conduits were found to have statistically greater number of regenerated axons at the midconduit and distal nerve site of implanted grafts, as compared to the silicone and non-asymmetric groups at 4 and 6 weeks. Of interest was that the results of 4 weeks in asymmetric groups were better than the non-asymmetric groups at 6 weeks in number of axons. According to the results of permeability, the asymmetric structure in the conduit wall seemed to enhance the removal of the blockage of the waste drain from the inner inflamed wound in the early stage, which may have improved the efficacy of the peripheral nerve regeneration. The asymmetric structure could be adequately employed in the

  3. Effects of particles size, componentry and conduit geometry on fragmentation processes.

    NASA Astrophysics Data System (ADS)

    Paredes, J.; Scheu, B.; Montanaro, C.; Arciniega-Ceballos, A.; Dingwell, D. B.; Perugini, D.

    2016-12-01

    The grain size distribution (GSD) is an important tool to characterize a volcanic deposit and to link it to eruptive processes. The GSD of a deposit is a complex product of primary fragmentation converting magma to tephra and secondary processes within the conduit and the subsequent way out of it. Particularly, the continuous interaction between tephra particles, together with the conduit geometry, play a crucial role in the secondary processes which in turn control the GSD of the ejected mixture. Here we present first results of a series of rapid decompression experiments aimed to evaluate the influence of the initial particle size and lithology, together with conduit geometry, on size reduction processes (gas-driven fragmentation, collision, abrasion). Loose material collected from the Pomici Principale eruption (10.3ka) fall deposit (Campi Flegrei) was used for the experiments. A physical separation allowed discriminating two main groups as 1) pumiceous fraction, and 2) lithic fraction, which included both crystal and lithic particles. The sample was slowly pressurized to 10MPa using argon gas and then rapidly decompressed. A transparent autoclave and sample holder were used to optimize the visual observation of particle's acceleration, collision and eventual fragmentation. Finally the ejected fragments were analyzed for their grain size distribution. Our first results suggest that 1) an increasing amount of lithics in the initial particle mixture produced an increased percentage of fines; 2) a significant amount of very fine material (<63μm) is produced independently of the presence of lithics, and 3) a reduction on the conduit diameter (analogous to obstacles within the conduit walls) is likely to further reduce the average diameter and increase the generation of very fine material.

  4. Arterial conduits for hepatic artery revascularisation in adult liver transplantation.

    PubMed

    Muralidharan, Vijayaragavan; Imber, Charles; Leelaudomlipi, Surasak; Gunson, Bridget K; Buckels, John A C; Mirza, Darius F; Mayer, A David; Bramhall, Simon R

    2004-05-01

    Arterial complications after orthotopic liver transplantation (OLT), including hepatic artery thrombosis (HAT), are important causes of early graft failure. The use of an arterial conduit is an accepted alternative to the utilisation of native recipient hepatic artery for specific indications. This study aims to determine the efficacy of arterial conduits and the outcome in OLT. We retrospectively reviewed 1,575 cadaveric adult OLTs and identified those in which an arterial conduit was used for hepatic revascularisation. Data on the primary disease, indication for using arterial conduit, type of vascular graft, operative technique and outcome were obtained. Thirty-six (2.3%) patients underwent OLT in which arterial conduits were used for hepatic artery (HA) revascularisation. Six of these were performed on the primary transplant, while the rest (n=30) were performed in patients undergoing re-transplantation, including six who had developed hepatic artery aneurysms. The incidence of arterial conduits was 0.4% (6/1,426 cases) in all primary OLTs and 20.1% (30/149 cases) in all re-transplants. Twenty-nine procedures utilised iliac artery grafts from the same donor as the liver, six used iliac artery grafts from a different donor, and a single patient underwent a polytetrafluoroethylene (PTFE) graft. Two techniques were used: infra-renal aorto-hepatic artery conduit and interposition between the donor and recipient native HAs, or branches of the HAs. The 30-day mortality rate for operations using an arterial conduit was 30.6%. Three conduits thrombosed at 9, 25 and 155 months, respectively, but one liver graft survived without re-transplantation. The arterial conduits had 1- and 5-year patency rates of 88.5% and 80.8%. The 1- and 5-year patient survival rates were 66.7% and 44%. We can thus conclude that an arterial conduit is a viable alternative option for hepatic revascularisation in both primary and re-transplantation. Despite a lower patency rate than that of

  5. 35. CONDUIT LAYOUT FOR BASCULE General overview with motors, brakes, ...

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

    35. CONDUIT LAYOUT FOR BASCULE General overview with motors, brakes, etc. Courtesy of Norwood Noonan Company, Chicago, 1930. - Congress Street Bascule Bridge, Spanning Fort Point Channel at Congress Street, Boston, Suffolk County, MA

  6. 79. COVERED CONDUIT ACROSS ANTELOPE VALLEY WITH WIND FARM IN ...

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

    79. COVERED CONDUIT ACROSS ANTELOPE VALLEY WITH WIND FARM IN DISTANCE - Los Angeles Aqueduct, From Lee Vining Intake (Mammoth Lakes) to Van Norman Reservoir Complex (San Fernando Valley), Los Angeles, Los Angeles County, CA

  7. 87. AQUEDUCT IN COVERED CONDUIT LOOKING NORTHWEST Los Angeles ...

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

    87. AQUEDUCT IN COVERED CONDUIT LOOKING NORTHWEST - Los Angeles Aqueduct, From Lee Vining Intake (Mammoth Lakes) to Van Norman Reservoir Complex (San Fernando Valley), Los Angeles, Los Angeles County, CA

  8. 98. (Credit BLV) Detail of gravity, flow conduit intake at ...

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

    98. (Credit BLV) Detail of gravity, flow conduit intake at cross Lake dam Cribbing supports extra suction intake installed in 1930. - McNeil Street Pumping Station, McNeil Street & Cross Bayou, Shreveport, Caddo Parish, LA

  9. 2. DETAIL, CONDUITS ALONG BASE OF NORTH FRONT. Looking east. ...

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

    2. DETAIL, CONDUITS ALONG BASE OF NORTH FRONT. Looking east. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-4, Test Area 1-115, northwest end of Saturn Boulevard, Boron, Kern County, CA

  10. 11. INTERIOR DETAIL, BASEMENT, SHOWING CONDUITS LEADING UNDERGROUND TO SWITCHES ...

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

    11. INTERIOR DETAIL, BASEMENT, SHOWING CONDUITS LEADING UNDERGROUND TO SWITCHES AND SIGNALS - Baltimore & Potomac Interlocking Tower, Adjacent to AMTRAK railroad tracks in block bounded by Howard Street, Jones Falls Expressway, Maryland Avenue & Falls Road, Baltimore, Independent City, MD

  11. Superconducting cable-in-conduit low resistance splice

    DOEpatents

    Artman, Thomas A.

    2003-06-24

    A low resistance splice connects two cable-in-conduit superconductors to each other. Dividing collars for arranging sub-cable units from each conduit are provided, along with clamping collars for mating each sub-cable wire assembly to form mated assemblies. The mated assemblies ideally can be accomplished by way of splicing collar. The mated assemblies are cooled by way of a flow of coolant, preferably helium. A method for implementing such a splicing is also described.

  12. Valved Polytetrafluoroethylene Conduits for Right Ventricular Outflow Tract Reconstruction.

    PubMed

    Shinkawa, Takeshi; Tang, Xinyu; Gossett, Jeffrey M; Mustafa, Thikra; Hategekimana, Festus; Watanabe, Fumiya; Miyazaki, Takako; Yamagishi, Masaaki; Imamura, Michiaki

    2015-07-01

    The purposes of this study were to review our early outcomes using valved expanded polytetrafluoroethylene (ePTFE) conduits, with or without bulging sinus structure, for right ventricular outflow tract reconstruction and to examine the mechanical properties of the ePTFE material after bulging sinuses were created. A retrospective review was performed of all patients who received the valved ePTFE conduit between 2008 and 2014 at a single institution. The surface morphologies and the mechanical strengths of the ePTFE conduit with bulging sinuses examined by scanning electron microscopy and unidirectional pull test were compared with those of the original ePTFE material. There were 120 operations with the valved ePTFE conduit (60 with bulging sinuses). The patients median age and weight were 6.9 years and 23.7 kg. The conduits were a median size of 22 mm. At 5 years, freedom from conduit reoperation was 92.7% (95% confidence interval, 82.7% to 97.0%), and freedom from severe conduit insufficiency or more than a 50 mm Hg gradient was 74.8% (95% confidence interval, 60.8% to 84.4%). No significant differences in the surface morphologies were observed by the scanning electron microscopy or in the maximum tolerated loads obtained by the pull test between the original ePTFE material and the ePTFE with bulging sinuses (121 and 122 N in longitudinal direction and 115 and 121 N in circumferential direction; p = 0.88 and p = 0.68). The valved ePTFE conduits demonstrated excellent early clinical outcomes. The mechanical property examinations showed no obvious difference after bulging sinuses were created on the ePTFE material. Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  13. Non-Newtonian flow of bubbly magma in volcanic conduits

    NASA Astrophysics Data System (ADS)

    Colucci, Simone; Papale, Paolo; Montagna, Chiara Paola

    2017-04-01

    The dynamics of magma ascent along volcanic conduits towards the Earth's surface affects eruptive styles and contributes to volcanic hazard. The rheology of ascending magmatic mixtures is known to play a major role on mass flow rate as well as on pressure and exit velocity at the vent, even determining effusive vs explosive eruptive behaviour. In this work we explore the effects of bubble-induced non-Newtonian rheology on the dynamics of magma flow in volcanic conduits. We develop a quasi-2D model of magma ascent that incorporates a rheological constitutive equation describing the strain-dependent effect of gas bubbles on the viscosity of the multiphase magma. Non-Newtonian magma flow is investigated through a parametric study where the viscosity of the melt and the water content are varied over natural ranges. Our results show that non-Newtonian rheology leads to greater exit velocity, mass flow, and density. The pressure distribution along the conduit remains very similar to the Newtonian case, deviating only at the conduit exit. Plug-like velocity profiles develop approaching the conduit exit, when mixture velocity is high, and are favored by smaller liquid viscosity. Since the mass flow rate, the density and the velocity of the mixture exiting from the conduit are fundamental for quantifying and assessing the transport and emplacement dynamics, neglecting the non-Newtonian effect of bubble-bearing magmas may result in misinterpretation of the deposit and, consequently, eruptive behavior.

  14. Non-Newtonian flow of bubbly magma in volcanic conduits

    NASA Astrophysics Data System (ADS)

    Colucci, S.; Papale, P.; Montagna, C. P.

    2017-03-01

    The dynamics of magma ascent along volcanic conduits toward the Earth's surface affects eruptive styles and contributes to volcanic hazard. The rheology of ascending magmatic mixtures is known to play a major role on mass flow rate as well as on pressure and exit velocity at the vent, even determining effusive versus explosive eruptive behavior. In this work we explore the effects of bubble-induced non-Newtonian rheology on the dynamics of magma flow in volcanic conduits. We develop a quasi 2-D model of magma ascent that incorporates a rheological constitutive equation describing the strain-dependent effect of gas bubbles on the viscosity of the multiphase magma. Non-Newtonian magma flow is investigated through a parametric study where the viscosity of the melt and the water content are varied over natural ranges. Our results show that non-Newtonian rheology leads to greater exit velocity, mass flow, and density. The pressure distribution along the conduit remains very similar to the Newtonian case, deviating only at the conduit exit. Plug-like velocity profiles develop approaching the conduit exit, when mixture velocity is high, and are favored by smaller liquid viscosity. Since the mass flow rate, the density and the velocity of the mixture exiting from the conduit are fundamental for quantifying and assessing the transport and emplacement dynamics, neglecting that the non-Newtonian effect of bubble-bearing magmas may result in misinterpretation of the deposit and, consequently, eruptive behavior.

  15. Comminution and frictional melting in volcanic conduits

    NASA Astrophysics Data System (ADS)

    Lavallee, Y.; Mitchell, T. M.; Heap, M. J.; Kendrick, J. E.; kennedy, B.; Ashwell, P. A.; Hirose, T.; Dingwell, D. B.

    2011-12-01

    Shearing and faulting at active volcanoes may differ to tectonic faulting due to their distinct temperature conditions above those of the Earth's geotherm. In particular, the ascent of high-viscosity magma/rocks in upper conduits leads to shear/fault zones, with/without gouge formation and sometimes frictional melting; yet, details of the deformation and fracture mechanisms in these magma/rocks with different crystallinities reveal a different synopsis. For instance, the extrusion of lava domes proceeds endogenously or exogenically - a distinction generally understood as a shift in magma rheology to brittle failure, without consideration of the subsequent slip process. Exogenic growth and formation of a spine follow the dynamic rupture of the lava and the dome carapace, and suffer slip along the fault surface. Here, we present experimental investigations of the ability of volcanic rocks (with different glass/crystal and vesicle ratios) to sustain friction, and in cases melt, using a high-velocity rotary apparatus. During high-velocity rotary shear test, we find that slip of along andesite and basalt rocks generate heat which leads to frictional melting at temperature of ca. 1000 C, conciding to a total slip of 10-40 m (for slip initiating at room temperature). In contrast, slip along dense obsidian rocks or porous rocks cannot sustain slip along a discrete plane. Alternatively, obsidian can be slipped against a crystalline material. The width of the slip zone decreases in the presence of crystals. The findings suggest that the comminution of crystals is a requirement to the development of a localised slip zone. In absence of crystals, obsidian (and crystal-free magma) shatter catastrophically. We discuss the implication of our findings to the cases of tectonic faults, stability of volcanic edifices and evolution of lava dome eruptions.

  16. Temperature limited heater with a conduit substantially electrically isolated from the formation

    SciTech Connect

    Vinegar, Harold J.; Sandberg, Chester Ledlie

    2009-07-14

    A system for heating a hydrocarbon containing formation is described. A conduit may be located in an opening in the formation. The conduit includes ferromagnetic material. An electrical conductor is positioned inside the conduit, and is electrically coupled to the conduit at or near an end portion of the conduit so that the electrical conductor and the conduit are electrically coupled in series. Electrical current flows in the electrical conductor in a substantially opposite direction to electrical current flow in the conduit during application of electrical current to the system. The flow of electrons is substantially confined to the inside of the conduit by the electromagnetic field generated from electrical current flow in the electrical conductor so that the outside surface of the conduit is at or near substantially zero potential at 25.degree. C. The conduit may generate heat and heat the formation during application of electrical current.

  17. Lorentz force effect on mixed convection micropolar flow in a vertical conduit

    NASA Astrophysics Data System (ADS)

    Abdel-wahed, Mohamed S.

    2017-05-01

    The present work provides a simulation of control and filtration process of hydromagnetic blood flow with Hall current under the effect of heat source or sink through a vertical conduit (pipe). This work meets other engineering applications, such as nuclear reactors cooled during emergency shutdown, geophysical transport in electrically conducting and heat exchangers at low velocity conditions. The problem is modeled by a system of partial differential equations taking the effect of viscous dissipation, and these equations are simplified and solved analytically as a series solution using the Differential Transformation Method (DTM). The velocities and temperature profiles of the flow are plotted and discussed. Moreover, the conduit wall shear stress and heat flux are deduced and explained.

  18. Laboratory simulations of tensile fracture development in a volcanic conduit via cyclic magma pressurisation

    NASA Astrophysics Data System (ADS)

    Benson, Philip M.; Heap, Michael J.; Lavallée, Yan; Flaws, Asher; Hess, K.-U.; Selvadurai, A. P. S.; Dingwell, Donald B.; Schillinger, B.

    2012-10-01

    During volcanic unrest, high magma pressure induces cracking and faulting of the country rock, providing conduits for the transport of magma and other fluids. These conduits, known as dykes, are fundamental structures for the transport of magma to the surface in volcanically active regions. The mechanics of dyke propagation is not yet fully understood but is crucial to better model dyke emplacement and eruption in volcanoes. Central to this need is a greater understanding of the mechanical properties of the magma/country rock interaction as a function of known magmatic pressure, temperature and stress. Here, we report data from a series of experiments in which we cyclically compress viscoelastic rhyolitic magma (at 828 °C, 892 °C and 918 °C) inside a cylindrical conduit-like shell of basalt (from Mt. Etna, Italy) until fracture occurs. The compression is performed under strain rates cyclically varying between 5×10-6 and 5×10-5 s-1. The resultant monitored (axial) loading and relaxation illustrates how the presence of a visco-elastic fluid (magma) controls the stress induced at the conduit margin boundary. This is achieved by analysing the viscoelastic relaxation (through time) to calculate an apparent modulus, which is found to decrease with both increasing temperature and time. In the 4 cycles before failure we find that the apparent modulus decreases from 180 to 40 GPa, 80 to 20 GPa and 8 to 1 GPa for imposed stress cycles at 828 °C, 892 °C and 918 °C, respectively. We theoretically estimate a tensile strength at failure of approximately 7-11 MPa, consistent with recent field data and in agreement with a model derived from the sample geometry and basic material parameters. Post-experimental neutron computed tomography and microscopic analyses further reveal the fragmentation of the melt and generation of tuffisite veins inside the conduit due to spontaneous crack nucleation associated with conduit wall fracture. The geometry of the rupture area inside the

  19. A conduit dilation model of methane venting from lake sediments

    USGS Publications Warehouse

    Scandella, B.P.; Varadharajan, C.; Hemond, Harold F.; Ruppel, C.; Juanes, R.

    2011-01-01

    Methane is a potent greenhouse gas, but its effects on Earth's climate remain poorly constrained, in part due to uncertainties in global methane fluxes to the atmosphere. An important source of atmospheric methane is the methane generated in organic-rich sediments underlying surface water bodies, including lakes, wetlands, and the ocean. The fraction of the methane that reaches the atmosphere depends critically on the mode and spatiotemporal characteristics of free-gas venting from the underlying sediments. Here we propose that methane transport in lake sediments is controlled by dynamic conduits, which dilate and release gas as the falling hydrostatic pressure reduces the effective stress below the tensile strength of the sediments. We test our model against a four-month record of hydrostatic load and methane flux in Upper Mystic Lake, Mass., USA, and show that it captures the complex episodicity of methane ebullition. Our quantitative conceptualization opens the door to integrated modeling of methane transport to constrain global methane release from lakes and other shallow-water, organic-rich sediment systems, and to assess its climate feedbacks.

  20. A conduit dilation model of methane venting from lake sediments

    NASA Astrophysics Data System (ADS)

    Scandella, Benjamin P.; Varadharajan, Charuleka; Hemond, Harold F.; Ruppel, Carolyn; Juanes, Ruben

    2011-03-01

    Methane is a potent greenhouse gas, but its effects on Earth's climate remain poorly constrained, in part due to uncertainties in global methane fluxes to the atmosphere. An important source of atmospheric methane is the methane generated in organic-rich sediments underlying surface water bodies, including lakes, wetlands, and the ocean. The fraction of the methane that reaches the atmosphere depends critically on the mode and spatiotemporal characteristics of free-gas venting from the underlying sediments. Here we propose that methane transport in lake sediments is controlled by dynamic conduits, which dilate and release gas as the falling hydrostatic pressure reduces the effective stress below the tensile strength of the sediments. We test our model against a four-month record of hydrostatic load and methane flux in Upper Mystic Lake, Mass., USA, and show that it captures the complex episodicity of methane ebullition. Our quantitative conceptualization opens the door to integrated modeling of methane transport to constrain global methane release from lakes and other shallow-water, organic-rich sediment systems, and to assess its climate feedbacks.

  1. Thermomechanical milling of accessory lithics in volcanic conduits

    NASA Astrophysics Data System (ADS)

    Campbell, Michelle E.; Russell, James K.; Porritt, Lucy A.

    2013-09-01

    Accessory lithic clasts recovered from pyroclastic deposits commonly result from the failure of conduit wall rocks, and represent an underutilized resource for constraining conduit processes during explosive volcanic eruptions. The morphological features of lithic clasts provide distinctive 'textural fingerprints' of processes that have reshaped them during transport in the conduit. Here, we present the first study focused on accessory lithic clast morphology and show how the shapes and surfaces of these accessory pyroclasts can inform on conduit processes. We use two main types of accessory lithic clasts from pyroclastic fallout deposits of the 2360 B.P. subplinian eruption of Mount Meager, British Columbia, as a case study: (i) rough and subangular dacite clasts, and (ii) variably rounded and smoothed monzogranite clasts. The quantitative morphological data collected on these lithics include: mass, volume, density, 2-D image analysis of convexity (C), and 3-D laser scans for sphericity (Ψ) and smoothness (S). Shaping and comminution (i.e. milling) of clasts within the conduit are ascribed to three processes: (1) disruptive fragmentation due to high-energy impacts between clasts or between clasts and conduit walls, (2) ash-blasting of clasts suspended within the volcanic flux, and (3) thermal effects. We use a simplified conduit eruption model to predict ash-blasting velocities and lithic residence times as a function of clast size and source depth, thereby constraining the lithic milling processes. The extent of shape and surface modification (i.e. rounding and honing) is directly proportional to clast residence times within the conduit prior to evacuation. We postulate that the shallow-seated dacite clasts remain subangular and rough due to short (<2 min) residence times, whereas monzogranite clasts are much more rounded and smoothed due to deeper source depths and consequently longer residence times (up to ˜1 h). Larger monzogranite clasts are smoother than

  2. Nanofiber-reinforced biological conduit in cardiac surgery: preliminary report.

    PubMed

    Guhathakurta, Soma; Galla, Satish; Ramesh, Balasundari; Venugopal, Jayarama Reddy; Ramakrishna, Seeram; Cherian, Kotturathu Mammen

    2011-06-01

    Several options are available for right ventricular outflow tract reconstruction, including commercially available bovine jugular vein and cryo-preserved homografts. Homograft non-availability and the problems of commercially available conduits led us to develop indigenously processed bovine jugular vein conduits with competent valves. They were made completely acellular and strengthened by non-conventional cross-linking without disturbing the extracellular matrix, which improved the luminal surface characteristics for hemocompatibility. Biocompatibility in vitro and in vivo, along with thermal stability, matrix stability, and mechanical strength have been evaluated. Sixty-nine patients received these conduits for right ventricular outflow tract reconstruction. Seven conduits dilated and 4 required replacement. To counteract dilatation, biodegradable polymeric nanofibers in various combinations and in isolation (collagen, polycaprolactone, polylactic acid) were characterized and used to reinforce the conduit circumferentially. Physical validation by mechanical testing, scanning electron microscopy, and in-vitro cytotoxicity was conducted. Thermal stability, spectroscopy studies of the polymer, and preclinical studies of the coated bovine jugular vein in animals are in progress. The feasibility studies have been completed, and the final polymer selection depends on evaluation of the functional superiority of the coated bovine jugular vein.

  3. In Vitro Study of Directly Bioprinted Perfusable Vasculature Conduits

    PubMed Central

    Zhang, Yahui; Yu, Yin; Akkouch, Adil; Dababneh, Amer; Dolati, Farzaneh

    2014-01-01

    The ability to create three dimensional (3D) thick tissues is still a major tissue engineering challenge. It requires the development of a suitable vascular supply for an efficient media exchange. An integrated vasculature network is particularly needed when building thick functional tissues and/or organs with high metabolic activities, such as the heart, liver and pancreas. In this work, human umbilical vein smooth muscle cells (HUVSMCs) were encapsulated in sodium alginate and printed in the form of vasculature conduits using a coaxial deposition system. Detailed investigations were performed to understand the dehydration, swelling and degradation characteristics of printed conduits. In addition, because perfusional, permeable and mechanical properties are unique characteristics of natural blood vessels, for printed conduits these properties were also explored in this work. The results show that cells encapsulated in conduits had good proliferation activities and that their viability increased during prolonged in vitro culture. Deposition of smooth muscle matrix and collagen was observed around the peripheral and luminal surface in long-term cultured cellular vascular conduit through histology studies. PMID:25574378

  4. Conductive PPY/PDLLA conduit for peripheral nerve regeneration

    PubMed Central

    Xu, Haixing; Holzwarth, Jeremy M.; Yan, Yuhua; Xu, Peihu; Zheng, Hua; Yin, Yixia; Li, Shipu; Ma, Peter X.

    2013-01-01

    The significant drawbacks and lack of success associated with current methods to treat critically sized nerve defects have led to increased interest in neural tissue engineering. Conducting polymers show great promise due to their electrical properties, and in the case of polypyrrole (PPY), its cell compatibility as well. Thus, the goal of this study is to synthesize a conducting composite nerve conduit with PPY and poly(D, L-lactic acid) (PDLLA), assess its ability to support the differentiation of rat pheochromocytoma 12 (PC12) cells in vitro, and determine its ability to promote nerve regeneration in vivo. Different amounts of PPY (5%, 10%, and 15%) are used to synthesize the conduits resulting in different conductivities (5.65, 10.40, and 15.56 ms/cm, respectively). When PC12 cells are seeded on these conduits and stimulated with 100 mV for 2 h, there is a marked increase in both the percentage of neurite-bearing cells and the median neurite length as the content of PPY increased. More importantly, when the PPY/PDLLA nerve conduit was used to repair a rat sciatic nerve defect it performed similarly to the gold standard autologous graft. These promising results illustrate the potential that this PPY/PDLLA conducting composite conduit has for neural tissue engineering. PMID:24138830

  5. Access to the native atria following conduit total cavopulmonary anastomosis.

    PubMed

    Petersen, Robert L; Danon, Saar; Jureidini, Saadeh

    2017-08-01

    We describe the use of trans-thoracic and trans-conduit puncture to access the atria and perform interventional procedures in patients who have undergone conduit total cavopulmonary anastomosis. Catheter access to the atria following intra or extra-cardiac Fontan is desirable when there is a need for trans-atrial interventions. Between 2009 and 2014, 5 patients ages 7 to 28 years underwent this approach; three trans-thoracic and 2 trans-conduit punctures. Various therapeutic aims were achieved. Included are: placement of pacing wire in the left atrial appendage, access to re-canalized left superior vena cava via the coronary sinus for device occlusion eliminating cyanosis, access with subsequent device closure of a dormant pulmonary valve thought to be the nidus of an embolic event, and access to the atria for ablation of an atrial tachycardia. Entry to the atria was successful in all five patients with either trans-thoracic access or trans-conduit puncture with subsequent intended intervention performed successfully. Trans-conduit puncture and trans-thoracic access may allow therapeutic procedures which mitigate the need for further open heart surgery. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  6. Geodynamic modeling of the capture and release of a plume conduit by a migrating mid-ocean ridge

    NASA Astrophysics Data System (ADS)

    Hall, P. S.

    2011-12-01

    plates over the relatively stationary, long-lived conduits of mantle plumes. However, paleomagnetic data from the Hawaii-Emperor Seamount Chain suggests that the Hawaiian hotspot moved rapidly (~40 mm/yr) between 81 - 47 Ma [Tarduno et al., 2003]. Recently, Tarduno et al. [2009] suggested that this period of rapid motion might be the surface expression of a plume conduit returning to a largely vertical orientation after having been captured and tilted as the result of being "run over" by migrating mid-ocean ridge. I report on a series of analog geodynamic experiments designed to characterize the evolution of a plume conduit as a mid-ocean ridge migrates over. Experiments were conducted in a clear acrylic tank (100 cm x 70 cm x 50 cm) filled with commercial grade high-fructose corn syrup. Plate-driven flow is modeled by dragging two sheets of Mylar film (driven by independent DC motors) in opposite directions over the surface of the fluid. Ridge migration is achieved by moving the point at which the mylar sheets diverge using a separate motor drive. Buoyant plume flow is generated using a small electrical heater placed at the bottom of the tank. Plate velocities and ridge migration rate are controlled and plume temperature monitored using LabView software. Experiments are recorded using digital video which is then analyzed using digital image analysis software to track the position and shape of the plume conduit throughout the course of the experiment. The intersection of the plume conduit with the surface of the fluid is taken as an analog for the locus of hotspot volcanism and tracked as a function of time to obtain a hotspot migration rate. Results show that the plume conduit experiences significant tilting immediately following the passage of the migrating ridge.

  7. Impact of the lithographic discontinuities on the karst conduit development - insights from modelling

    NASA Astrophysics Data System (ADS)

    Petrus, Karine; Szymczak, Piotr

    2016-04-01

    Karst formation is controlled by the processes of the fluid flow and reactant transport coupled to the chemical erosion of the limestone rock [1]. The coupling between these processes can lead to a number of different instabilities, resulting in the formation of dissolutional voids, caverns and conduits. Arguably the simplest systems of this kind are solution pipes, in which gravitationally driven water movement carves vertical conduits in limestone rocks. In the homogeneous rocks these conduits are often cylindrical, with almost a constant diameter along their length. However, in a stratified medium, the morphology of the pipes changes. For example, if a number of less porous layers is introduced in an otherwise homogeneous medium, then the pipes are observed to narrow as they cross the layers and then widen up to form bulbous caverns as they emerge from the layer [1]. In this communication, we investigate these effects more closely, considering different kind of lithographic discontinuities to be present in the system: the layers of increased/decreased porosity and/or permeability as well as the solubility which is different from the rest of the system. Using a Darcy-scale numerical model we analyze the effects these layers have on the shape and growth of solution pipes and compare the results on the piping morphologies observed in nature. Finally we comment on the possible relevance of these results to the cave-formation phenomena and the inception horizon concept [3]. References: 1.Howard A. D., The development of karst features, Bull. Natl. Spel. Soc. 25, 45-65 (1963) 2. Petrus, K. and Szymczak, P., Influence of layering on the formation and growth of solution pipes. Frontiers in Physics (submitted) 3.Filipponi , M., Jeannin, P. and Tacher, L., Evidence of inception horizons in karst conduit networks, Geomorphology, 106, 86-99 (2009)

  8. Differential expression of GAP-43 and neurofilament during peripheral nerve regeneration through bio-artificial conduits.

    PubMed

    Carriel, Víctor; Garzón, Ingrid; Campos, Antonio; Cornelissen, Maria; Alaminos, Miguel

    2017-02-01

    Nerve conduits are promising alternatives for repairing nerve gaps; they provide a close microenvironment that supports nerve regeneration. In this sense, histological analysis of axonal growth is a determinant to achieve successful nerve regeneration. To evaluate this process, the most-used immunohistochemical markers are neurofilament (NF), β-III tubulin and, infrequently, GAP-43. However, GAP-43 expression in long-term nerve regeneration models is still poorly understood. In this study we analysed GAP-43 expression and its correlation with NF and S-100, using three tissue-engineering approaches with different regeneration profiles. A 10 mm gap was created in the sciatic nerve of 12 rats and repaired using collagen conduits or collagen conduits filled with fibrin-agarose hydrogels or with hydrogels containing autologous adipose-derived mesenchymal stem cells (ADMSCs). After 12 weeks the conduits were harvested for histological analysis. Our results confirm the long-term expression of GAP-43 in all groups. The expression of GAP-43 and NF was significantly higher in the group with ADMSCs. Interestingly, GAP-43 was observed in immature, newly formed axons and NF in thicker and mature axons. These proteins were not co-expressed, demonstrating their differential expression in newly formed nerve fascicles. Our descriptive and quantitative histological analysis of GAP-43 and NFL allowed us to determine, with high accuracy, the heterogenic population of axons at different stages of maturation in three tissue-engineering approaches. Finally, to perform a complete assessment of axonal regeneration, the quantitative immunohistochemical evaluation of both GAP-43 and NF could be a useful quality control in tissue engineering. Copyright © 2014 John Wiley & Sons, Ltd.

  9. Aeration efficiency of free-surface conduit flow systems.

    PubMed

    Unsal, M; Baylar, A; Tugal, M; Ozkan, F

    2009-12-14

    Dissolved oxygen is a measure of the quantity of oxygen present in water and is one of the best indicators of the health of a water ecosystem. Dissolved oxygen levels in water can be increased by creating turbulent conditions where fine air bubbles are carried into the bulk of the flow. This is achieved by hydraulic structures. A free-surface conduit is a particular instance of this. In the present work, a series of experiments were conducted to investigate the aeration efficiency of free-surface conduit flow systems. The results indicate that free-surface conduit flow systems are very effective for oxygen transfer. At Froude numbers greater than 15, almost full oxygen transfer up to the saturation value was reached. Moreover, from experimental data, a regression equation was obtained with a very high correlation coefficient, showing the effect of various parameters on the aeration efficiency.

  10. Endoscopic Treatment of Stump Leakage Related to the Ileal Conduit

    PubMed Central

    Odemis, Bulent; Oztas, Erkin; Akpinar, Muhammet Yener; Olcucuoglu, Erkan; Kayacetin, Ertugrul

    2016-01-01

    Abstract Background: Ileal conduit with leakage from either the anastomotic site or the stump is associated with high morbidity and mortality rates. The standard treatment of stump leakage is surgery. Case Presentation: A 60-year-old male patient was admitted to our hospital with complaint of hematuria and bladder carcinoma was diagnosed. After performing radical cystectomy and ileal conduit, he developed fever with abdominal pain within the first week of surgery. Stump leakage was diagnosed by endoscopic examination performed through a gastroscope. After two over-the-scope clips (OTSCs) were applied to the stump, vinyl mesh was inserted into the space between the OTSCs. Later, cyanoacrylat and lipiodol were repelled on the OTSCs and vinyl mesh. Subsequently, stump leakage was resolved. Conclusion: This is the first case of stump leakage related to ileal conduit that has been treated endoscopically, according to the current literature. PMID:27579432

  11. Linking Volcano Infrasound Observations to Conduit Processes for Vulcanian Eruptions

    NASA Astrophysics Data System (ADS)

    Watson, L. M.; Dunham, E. M.; Almquist, M.; Mattsson, K.; Ampong, K.

    2016-12-01

    Volcano infrasound observations have been used to infer a range of eruption parameters, such as volume flux and exit velocity, with the majority of work focused on subaerial processes. Here, we propose using infrasound observations to investigate the subsurface processes of the volcanic system. We develop a one-dimensional model of the volcanic system, coupling an unsteady conduit model to a description of a volcanic jet with sound waves generated by the expansion of the jet. The conduit model describes isothermal two-phase flow with no relative motion between the phases. We are currently working on including crystals and adding conservation of energy to the governing equations. The model captures the descent of the fragmentation front into the conduit and approaches a steady state solution with choked flow at the vent. The descending fragmentation front influences the time history of mass discharge from the vent, which is linked to the infrasound signal through the volcanic jet model. The jet model is coupled to the conduit by conservation of mass, momentum, and energy. We compare simulation results for a range of models of the volcanic jet, ranging in complexity from assuming conservation of volume, as has been done in some previous infrasound studies, to solving the Euler equations for the surrounding compressible atmosphere and accounting for entrainment. Our model is designed for short-lived, impulsive Vulcanian eruptions, such as those seen at Sakurajima Volcano, with activity triggered by a sudden drop in pressure at the top of the conduit. The intention is to compare the simulated signals to observations and to devise an inverse procedure to enable inversion for conduit properties.

  12. Past, Present, and Future of Nerve Conduits in the Treatment of Peripheral Nerve Injury

    PubMed Central

    Muheremu, Aikeremujiang

    2015-01-01

    With significant advances in the research and application of nerve conduits, they have been used to repair peripheral nerve injury for several decades. Nerve conduits range from biological tubes to synthetic tubes, and from nondegradable tubes to biodegradable tubes. Researchers have explored hollow tubes, tubes filled with scaffolds containing neurotrophic factors, and those seeded with Schwann cells or stem cells. The therapeutic effect of nerve conduits is improving with increasing choice of conduit material, new construction of conduits, and the inclusion of neurotrophic factors and support cells in the conduits. Improvements in functional outcomes are expected when these are optimized for use in clinical practice. PMID:26491662

  13. Assessing the importance of conduit geometry and physical parameters in karst systems using the storm water management model (SWMM)

    NASA Astrophysics Data System (ADS)

    Peterson, Eric W.; Wicks, Carol M.

    2006-09-01

    SummaryQuestions about the importance of conduit geometry and about the values of hydraulic parameters in controlling ground-water flow and solute transport through karstic aquifers have remained largely speculative. One goal of this project was to assess the role that the conduit geometry and the hydraulic parameters have on controlling transport dynamics within karstic aquifers. The storm water management model (SWMM) was applied to the Devil's Icebox-Connor's Cave System in central Missouri, USA. Simulations with incremental changes to conduit geometry or hydraulic parameters were performed with the output compared to a calibrated baseline model. Ten percent changes in the length or width of a conduit produced statistically significant different fluid flow responses. The model exhibited minimal sensitivity to slope and infiltration rates; however, slight changes in Manning's roughness coefficient can highly alter the simulated output. Traditionally, the difference in flow dynamics between karstified aquifers and porous media aquifers has led to the idea that modeling of karst aquifers is more difficult and less precise than modeling of porous media aquifers. When evaluated against models for porous media aquifers, SWMM produced results that were as accurate (10% error compared to basecase). In addition, SWMM has the advantage of providing data about local flow. While SWMM may be an appropriate modeling technique for some karstic aquifers, SWMM should not be viewed as a universal solution to modeling karst systems.

  14. Ash Production in Eruptive Flows: Comminution in Conduits and Pyroclastic Flows

    NASA Astrophysics Data System (ADS)

    Dufek, J.; Manga, M.; Patel, A.

    2009-05-01

    Processes occurring at the grain scale, termed microphysical processes, can exert strong control of explosive eruption dynamics. In this talk we illustrate the importance of particle-particle interaction on the mass and momentum balance of eruptive flows. In particular we examine the break-up and transport of clasts during particle-particle interactions for two high-energy flow environments: pyroclastic and conduit flows. Abrasion and comminution of pumice clasts during the propagation of pyroclastic flows and post-fragmentation conduit flow have long been recognized as a potential source for the enhanced production of volcanic ash, however its relative importance has eluded quantification. The amount of fine-material produced in-situ can potentially affect runout distance, deposit sorting, the volume of ash introduced in the upper atmosphere, and internal pore pressure in pyroclastic flows. We conduct a series of laboratory experiments on the collisional production of ash that may occur during different regimes of pyroclastic flow transport and conduit flow. Using these laboratory experiments we develop a subgrid model for ash production that can be included in analytical and multiphase numerical procedures to estimate the total volume of ash produced during transport. We find that for most pyroclastic flow conditions, 10-20% of the initially 1 cm clasts comminutes into ash with the percentage increasing as a function of initial flow energy. Most of the ash is produced in the high-energy regions near the flow inlet, although flow acceleration on steep slopes can produce ash far from the vent. On level terrain, collisionally and frictionally produced ash generates gravity currents that detach from the main flow. Ash produced at the frictional base of the flow and in the collisional upper regions of the flow can be redistributed through the entirety of the flow, although frictionally produced ash accumulates preferentially near its source in the bed load. Flows that

  15. 24. Lake Hodges Flume conduit enlargement. April 1930. Courtesy of ...

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

    24. Lake Hodges Flume conduit enlargement. April 1930. Courtesy of the Mandeville Department of Special Collections, Central Library, University of California, San Diego. - Lake Hodges Flume, Along San Dieguito River between Lake Hodges & San Dieguito Reservoir, Rancho Santa Fe, San Diego County, CA

  16. Evaluation of the MODFLOW-2005 Conduit Flow Process.

    PubMed

    Hill, Melissa E; Stewart, Mark T; Martin, Angel

    2010-01-01

    The recent development of the Conduit Flow Process (CFP) by the U.S. Geological Survey (USGS) provides hydrogeologic modelers with a new tool that incorporates the non-Darcian, multiporosity components of flow characteristic of karst aquifers. CFP introduces new parameters extending beyond those of traditional Darcian groundwater flow codes. We characterize a karst aquifer to collect data useful for evaluating this new tool at a test site in west-central Florida, where the spatial distribution and cross-sectional area of the conduit network are available. Specifically, we characterize: (1) the potential for Darcian/non-Darcian flow using estimates of specific discharge vs. observed hydraulic gradients, and (2) the temporal variation for the direction and magnitude of fluid exchange between the matrix and conduit network during extreme hydrologic events. We evaluate the performance of CFP Mode 1 using a site-scale dual-porosity model and compare its performance with a comparable laminar equivalent continuum model (ECM) using MODFLOW-2005. Based on our preliminary analyses, hydraulic conductivity coupled with conduit wall conductance improved the match between observed and simulated discharges by 12% to 40% over turbulent flow alone (less than 1%).

  17. Structure of a bacterial cell surface decaheme electron conduit

    USDA-ARS?s Scientific Manuscript database

    Some bacterial species are able to utilize extracellular mineral forms of iron and manganese as respiratory electron acceptors. In Shewanella oneidensis this involves decaheme cytochromes that are located on the bacterial cell surface at the termini of trans-outer-membrane electron transfer conduits...

  18. Robotic implantation of biodegradable regenerative urinary conduit: experimental study.

    PubMed

    de Castro Abreu, Andre Luis; Azhar, Raed A; Berger, Andre K; Chopra, Sameer; Marien, Arnaud; Santomauro, Michael; Satkunasivam, Raj; Sun, Yi; Aron, Monish; Ukimura, Osamu; Desai, Mihir M; Gill, Inderbir S

    2015-01-01

    To determine the feasibility and develop a robotic technique for intracorporeal implantation of a biodegradable tubular scaffold seeded with adipose-sourced smooth muscle cells (Neo-Urinary-Conduit) that, when implanted as a conduit for urinary diversion, facilitates regeneration of native-like neourinary tissue. Robotic NUC implantation was performed in two fresh male cadavers. The greater omentum was widely detached from the greater curvature of the stomach, in preparation for final wrapping of the conduit. Bilateral ureters were mobilized for implantation. The NUC, with two precreated ureteral openings, was inserted into the abdomen. Bilateral, stented uretero-NUC anastomoses were created. The NUC was circumferentially wrapped with the predissected omentum, exteriorized through the abdominal wall, and maturated. Both procedures were successfully completed intracorporeally. Operative time for NUC implantation was 90 and 100 minutes, respectively. Examination of gross anatomy showed no injury to other organs. There was no omental kinking, rotation, eversion, or stripping from the NUC. Bilateral stents were confirmed to be in situ with the proximal coil in the kidney. Uretero-NUC anastomoses and omentum were tension free. The entire NUC, including its distal edge and posterior aspect, was circumferentially wrapped 360 degrees. We demonstrated the feasibility and developed a robotic technique for intracorporeal implantation of a biodegradable regenerative urinary conduit. This study serves as the foundation for the robotic surgical technique before the clinical application.

  19. Growth of normal zones in cable-in-conduit superconductors

    SciTech Connect

    Dresner, L.

    1983-01-01

    A picture is proposed in which the growth of normal zones in cable-in-conduit superconductors is caused by the expansion of hot helium along the length of the conductor. Quantitative results suitable for experimental testing have been obtained by dimensional and similarity arguments. The results indicate non-uniform propagation at velocities of tens of meters per second.

  20. Intraoperative in situ radial artery conduit flow assessment.

    PubMed

    Canver, Charles C; Yousafzai, Sajjad M

    2008-01-01

    A technique is described for simple flow assessment of the in situ radial artery conduit during coronary bypass via a small incision. This technique allows morphologic and physiologic direct intraoperative assessment of radial artery quality and expands the use of radial artery during coronary artery surgery.

  1. 21. COMPLETION OF INTAKE CONDUITS REVISED, PIPE SECTIONS AND PLANS, ...

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

    21. COMPLETION OF INTAKE CONDUITS REVISED, PIPE SECTIONS AND PLANS, SHEET 117 OF 117, 1922. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  2. 14. PROJECT PLAN, INTAKE PIER, RAW WATER CONDUITS, PUMPING STATION ...

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

    14. PROJECT PLAN, INTAKE PIER, RAW WATER CONDUITS, PUMPING STATION FORCE MAINS, TREATED WATER PIPELINES, AND FILTRATION PLANT, SHEET 1 OF 117, 1920. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  3. The sensitivity of conduit flow models to basic input parameters: there is no need for magma trolls!

    NASA Astrophysics Data System (ADS)

    Thomas, M. E.; Neuberg, J. W.

    2012-04-01

    Many conduit flow models now exist and some of these models are becoming extremely complicated, conducted in three dimensions and incorporating the physics of compressible three phase fluids (magmas), intricate conduit geometries and fragmentation processes, to name but a few examples. These highly specialised models are being used to explain observations of the natural system, and there is a danger that possible explanations may be getting needlessly complex. It is coherent, for instance, to propose the involvement of sub-surface dwelling magma trolls as an explanation for the change in a volcanoes eruptive style, but assuming the simplest explanation would prevent such additions, unless they were absolutely necessary. While the understanding of individual, often small scale conduit processes is increasing rapidly, is this level of detail necessary? How sensitive are these models to small changes in the most basic of governing parameters? Can these changes be used to explain observed behaviour? Here we will examine the sensitivity of conduit flow models to changes in the melt viscosity, one of the fundamental inputs to any such model. However, even addressing this elementary issue is not straight forward. There are several viscosity models in existence, how do they differ? Can models that use different viscosity models be realistically compared? Each of these viscosity models is also heavily dependent on the magma composition and/or temperature, and how well are these variables constrained? Magma temperatures and water contents are often assumed as "ball-park" figures, and are very rarely exactly known for the periods of observation the models are attempting to explain, yet they exhibit a strong controlling factor on the melt viscosity. The role of both these variables will be discussed. For example, using one of the available viscosity models a 20 K decrease in temperature of the melt results in a greater than 100% increase in the melt viscosity. With changes of

  4. FATIGUE PROPERTIES OF MODIFIED 316LN STAINLESS STEEL AT 4 K FOR HIGH FIELD CABLE-IN-CONDUIT APPLICATIONS

    SciTech Connect

    Toplosky, V. J.; Walsh, R. P.; Han, K.

    2010-04-08

    Cable-In-Conduit-Conductor (CICC) alloys, exposed to Nb{sub 3}Sn reaction heat-treatments, such as modified 316LN require a design specific database. A lack of fatigue life data (S-n curves) that could be applied in the design of the ITER CS and the NHMFL Series Connected Hybrid magnets is the impetus for the research presented here. The modified 316LN is distinguished by a lower carbon content and higher nitrogen content when compared to conventional 316LN. Because the interstitial alloying elements affect the mechanical properties significantly, it is necessary to characterize this alloy in a systematic way. In conjunction, to ensure magnet reliability and performance, several criteria and expectations must be met, including: high fatigue life at the operating stresses, optimal stress management at cryogenic temperatures and thin walled conduit to reduce coil mass. Tension-tension load control axial fatigue tests have good applicability to CICC solenoid magnet design, thus a series of 4 K strength versus fatigue life curves have been generated. In-situ samples of 316LN base metal, seam welded, butt welded and seam plus butt welded are removed directly from the conduit in order to address base and weld material fatigue life variability. The more than 30 fatigue tests show good grouping on the fatigue life curve and allow discretionary 4 K fatigue life predictions for conduit made with modified 316LN.

  5. Draining mafic magma from conduits during Strombolian eruption

    NASA Astrophysics Data System (ADS)

    Wadsworth, F. B.; Kennedy, B.; Branney, M. J.; Vasseur, J.; von Aulock, F. W.; Lavallée, Y.; Kueppers, U.

    2014-12-01

    During and following eruption, mafic magmas can readily drain downward in conduits, dykes and lakes producing complex and coincident up-flow and down-flow textures. This process can occur at the top of the plumbing system if the magma outgases as slugs or through porous foam, causing the uppermost magma surface to descend and the magma to densify. In this scenario the draining volume is limited by the gas volume outgassed. Additionally, magma can undergo wholesale backflow when the pressure at the base of the conduit or feeder dyke exceeds the driving pressure in the chamber beneath. This second scenario will continue until pressure equilibrium is established. These two scenarios may occur coincidently as local draining of uppermost conduit magma by outgassing can lead to wholesale backflow because the densification of magma is an effective way to modify the vertical pressure profile in a conduit. In the rare case where conduits are preserved in cross section, the textural record of draining is often complex and great care should be taken in interpreting bimodal kinematic trends in detail. Lateral cooling into country rock leads to lateral profiles of physical and flow properties and, ultimately, outgassing potential, and exploration of such profiles elucidates the complexity involved. We present evidence from Red Crater volcano, New Zealand, and La Palma, Canary Islands, where we show that at least one draining phase followed initial ascent and eruption. We provide a rheological model approach to understand gravitational draining velocities and therefore, the timescales of up- and down-flow cycles predicted. These timescales can be compared with observed geophysical signals at monitored mafic volcanoes worldwide. Finally, we discuss the implications of shallow magma draining for edifice stability, eruption longevity and magma-groundwater interaction.

  6. Sleep and quality of life in people with ileal conduit.

    PubMed

    Cavdar, Ikbal; Temiz, Zeynep; Ozbas, Ayfer; Can, Gulbeyaz; Tarhan, Fatih; Findik, Ummu Yildiz; Kutlu, Fatma Yasemin; Akyuz, Nuray

    2016-12-01

    The aim of this study was to determine the sleep quality and the association between sleep quality and quality of life in people with ileal conduit. A descriptive and cross-sectional design was adopted. The study sample comprised 111 people with ileal conduit operated on in urology clinics in a state hospital between January 2011 and May 2014. Six months after the operation, they were called by telephone to participate in the study. Data for the study were collected using a questionnaire form, the Pittsburgh Sleep Quality Index (PSQI) and the Stoma Quality of Life Scale (SQLS). The mean ± SD total PSQI score of the people with ileal conduit was 10.20 ± 2.95, mean total score of SQLS was 43.63 ± 7.21, mean Work/Social Function domain score was 37.27 ± 5.80 and mean Stoma Function domain score was 50.0 ± 12.56. The total sleep quality had a low degree of negative correlation with total SQLS score, a medium degree of negative correlation with Work/Social Function (r = -0.327, p < .001) and no correlation with Stoma Function (r = -0.096, p > .001). People using a night drainage system had higher sleep quality. This study determined that quality of life and sleep deteriorate in people with ileal conduit. The quality of life decreases when the sleep quality is poor, and decreased quality of life affects quality of sleep in people with ileal conduit.

  7. Spectral Analysis of Surface Waves to Detect Buried Concrete Conduits

    NASA Astrophysics Data System (ADS)

    Hajiani, P.; Anderson, N.; Rogers, J. D.; Elkrry, A.

    2016-12-01

    The detection of underground cavities is of significant concern to geotechnical engineers working in karst terrain. In spite of the marked progress in nondestructive geophysical methods for detecting shallow underground voids, no unique methodology has emerged that can be applied globally. Various studies have been performed on the use of Rayleigh waves to detect shallow tunnels. In this study, we examined the potential of both Rayleigh and Love waves for detecting subsurface voids. Vertical geophones with Eigen-frequencies of 4.5 Hz, 14 Hz, and 100 Hz were utilized to evaluate Rayleigh waves to resolve near-surface tunnels. Seismic surveys were carried out using horizontal 14 Hz geophones to verify the feasibility of using Love waves to detect shallow tunnels. Two buried conduits of known size and embedment were chosen for the study. One conduit serves as a spillway outfall for an embankment dam, and the other as a low flow outlet for aa flood retention basin. Attenuation analyses of surface waves were performed on all of the data sets to identify locations of the buried concrete conduits. In order to minimize the far-field effects, such as body-wave domination, or low signal-to-noise ratio, it was suggested that we try muting the direct waves, refraction, reflection, air wave, and ambient noise. An amplification of energy on, or in front of the near boundary of the conduits was thereby observed. The muting process greatly reduced the number of false positives. The results of this study not only confirmed previous work, but also displayed the ability of Love waves in detecting the shallow subsurface tunnels or conduits.

  8. Combined physical and chemical nonequilibrium transport model for solution conduits.

    PubMed

    Field, Malcolm S; Leij, Feike J

    2014-02-01

    Solute transport in karst aquifers is primarily constrained to relatively complex and inaccessible solution conduits where transport is often rapid, turbulent, and at times constrictive. Breakthrough curves generated from tracer tests in solution conduits are typically positively-skewed with long tails evident. Physical nonequilibrium models to fit breakthrough curves for tracer tests in solution conduits are now routinely employed. Chemical nonequilibrium processes are likely important interactions, however. In addition to partitioning between different flow domains, there may also be equilibrium and nonequilibrium partitioning between the aqueous and solid phases. A combined physical and chemical nonequilibrium (PCNE) model was developed for an instantaneous release similar to that developed by Leij and Bradford (2009) for a pulse release. The PCNE model allows for partitioning open space in solution conduits into mobile and immobile flow regions with first-order mass transfer between the two regions to represent physical nonequilibrium in the conduit. Partitioning between the aqueous and solid phases proceeds either as an equilibrium process or as a first-order process and represents chemical nonequilibrium for both the mobile and immobile regions. Application of the model to three example breakthrough curves demonstrates the applicability of the combined physical and chemical nonequilibrium model to tracer tests conducted in karst aquifers, with exceptionally good model fits to the data. The three models, each from a different state in the United States, exhibit very different velocities, dispersions, and other transport properties with most of the transport occurring via the fraction of mobile water. Fitting the model suggests the potentially important interaction of physical and chemical nonequilibrium processes.

  9. Rationale, study design and sample characteristics of a randomized controlled trial of directly administered antiretroviral therapy for HIV-infected prisoners transitioning to the community - a potential conduit to improved HIV treatment outcomes.

    PubMed

    Saber-Tehrani, Ali Shabahang; Springer, Sandra A; Qiu, Jingjun; Herme, Maua; Wickersham, Jeffrey; Altice, Frederick L

    2012-03-01

    HIV-infected prisoners experience poor HIV treatment outcomes post-release. Directly administered antiretroviral therapy (DAART) is a CDC-designated, evidence-based adherence intervention for drug users, yet untested among released prisoners. Sentenced HIV-infected prisoners on antiretroviral therapy (ART) and returning to New Haven or Hartford, Connecticut were recruited and randomized 2:1 to a prospective controlled trial (RCT) of 6 months of DAART versus self-administered therapy (SAT); all subjects received case management services. Subjects meeting DSM-IV criteria for opioid dependence were offered immediate medication-assisted treatment. Trained outreach workers provided DAART once-daily, seven days per week, including behavioral skills training during the last intervention month. Both study groups were assessed for 6 months after the intervention period. Assessments occurred within 90 days pre-release (baseline), day of release, and then monthly for 12 months. Viral load (VL) and CD4 testing was conducted baseline and quarterly; genotypic resistance testing was conducted at baseline, 6 and 12 months. The primary outcome was pre-defined as viral suppression (VL<400 copies/mL) at 6 months. Between 2004 and 2009, 279 participants were screened, of which 202 met eligibility criteria and 154 were ultimately enrolled in the study; 103 subjects were randomized to DAART and 51 to SAT. Subjects were mostly male (81.2%), people of color (87.0%), had an alcohol use disorder (39.7%), had underlying depression (54.2%), were virally suppressed (78.8%) and had a mean CD4=390.7 cells/mL. Outcomes from this RCT will contribute greatly to HIV treatment outcomes after release from prison, a period associated with adverse HIV and other medical consequences. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. Hemiresective reconstruction of a redundant ileal conduit with severe bilateral ileal conduit-ureteral re fl ux.

    PubMed

    Fujimura, Tetsuya; Minowada, Shigeru; Kishi, Hiroichi; Hamasaki, Kimihisa; Saito, Kiyoshi; Kitamura, Tadaichi

    2005-10-01

    A 58-year-old man was referred to our hospital with high fever and anuria. Since undergoing a total pelvic exenteration due to bladder-invasive sigmoid colon cancer, urinary tract infections had frequently occurred. We treated with the construction of a bilateral percutaneous nephrostomy (PCN), and chemotherapy. Although we replaced the PCN with a single J ureteral catheter after an improvement of infection, urinary infection recurred because of an obstruction of the catheter. Urological examinations showed that an ileal conduit-ureteral reflux caused by kinking of the ileal loop was the reason why frequent pyelonephritis occurred. We decided to resect the proximal segment to improve conduit-ureteral reflux for the resistant pyelonephritis. After the surgery, the excretory urogram showed improvement and the urinary retention at the ileal conduit disappeared. Three years after the operation, renal function has been stable without episodes of pyelonephritis. Here we report a case of open repair surgery of an ileal conduit in a patient with severe urinary infection.

  11. Results and analysis of the hot-spot temperature experiment for a cable-in-conduit conductor with thick conduit

    NASA Astrophysics Data System (ADS)

    Sedlak, Kamil; Bruzzone, Pierluigi

    2015-12-01

    In the design of future DEMO fusion reactor a long time constant (∼23 s) is required for an emergency current dump in the toroidal field (TF) coils, e.g. in case of a quench detection. This requirement is driven mainly by imposing a limit on forces on mechanical structures, namely on the vacuum vessel. As a consequence, the superconducting cable-in-conduit conductors (CICC) of the TF coil have to withstand heat dissipation lasting tens of seconds at the section where the quench started. During that time, the heat will be partially absorbed by the (massive) steel conduit and electrical insulation, thus reducing the hot-spot temperature estimated strictly from the enthalpy of the strand bundle. A dedicated experiment has been set up at CRPP to investigate the radial heat propagation and the hot-spot temperature in a CICC with a 10 mm thick steel conduit and a 2 mm thick glass epoxy outer electrical insulation. The medium size, ∅ = 18 mm, NbTi CICC was powered by the operating current of up to 10 kA. The temperature profile was monitored by 10 temperature sensors. The current dump conditions, namely the decay time constant and the quench detection delay, were varied. The experimental results show that the thick conduit significantly contributes to the overall enthalpy balance, and consequently reduces the amount of copper required for the quench protection in superconducting cables for fusion reactors.

  12. 30 CFR 75.700 - Grounding metallic sheaths, armors, and conduits enclosing power conductors.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... conduits enclosing power conductors. 75.700 Section 75.700 Mineral Resources MINE SAFETY AND HEALTH... Grounding § 75.700 Grounding metallic sheaths, armors, and conduits enclosing power conductors. All metallic sheaths, armors, and conduits enclosing power conductors shall be electrically continuous throughout...

  13. Cryovolcanic Conduit Evolution and Eruption on Icy Satellites

    NASA Astrophysics Data System (ADS)

    Mitchell, K. L.

    2014-12-01

    In silicate volcanism, such as on Earth or Io, eruptions typically result from fracture formation caused by interaction of tectonic stresses with inflating, pressurized magma sources, leading to transport of melt through an evolving conduit. On icy satellites the paradigm may be similar, resulting from some combination of tidal stresses and expansion of freezing water within, or near the base of, an ice shell. Such a fracture will result in eruption if mass continuity can be established, with buoyancy aided by exsolution and expansion of dissolved volatiles. After onset, conduit shape evolves due to: (1) shear-stresses or frictional erosional; (2) wallrock "bursting" due to massive wall stresses; (3) wall melting or condensation of particles due to heat transfer; or (4) changes in applied stresses. Preliminary thermodynamic and fluid mechanical analysis suggests some initial cooling during ascent resulting from exsolution and expansion of volatiles, thermally buffered by freezing, Conduit contraction may occur, and so evolution towards a deep, gas-filled plume chamber is difficult to accommodate without evoking a co-incidental process. Conduit flaring occurs near the surface where velocities are greatest, enhancing erosion. Here, viscous dissipative heating exceeds adiabatic cooling, and so some boiling (a few wt%) may occur. In contrast with silicate volcanism, decompression to below the triple point will occur within conduit, vent or jet, resulting in rapid freezing and boiling of the remaining water at a 6.8:1 ratio. Subsequent isentropic or adiabatic expansion within erupting jets may result in a few percent net of condensation or sublimation. These effects combined lead to ~4:1-7:1 solid:vapor ratios in the jet for most eruption conditions. These figures are consistent with the ~6:1 inferred in Enceladus' jets, supporting the hypothesis that the Enceladus plume draws from a subsurface body of liquids through a conduit. Similar results are anticipated if

  14. Single-friction-surface triboelectric generator with human body conduit

    SciTech Connect

    Meng, Bo; Cheng, Xiaoliang; Zhang, Xiaosheng; Han, Mengdi; Liu, Wen; Zhang, Haixia

    2014-03-10

    We present a transparent single-friction-surface triboelectric generator (STEG) employing human body as the conduit, making the applications of STEG in portable electronics much more practical and leading to a significant output improvement. The STEG with micro-patterned polydimethylsiloxane surface achieved an output voltage of over 200 V with a current density of 4.7 μA/cm{sup 2}. With human body conduit, the output current increased by 39% and the amount of charge that transferred increased by 34% compared to the results with grounded electrode. A larger increment of 210% and 81% was obtained in the case of STEG with a large-size flat polyethylene terephthalate surface.

  15. Impulsive Wave Propagation within Magmatic Conduits with Axial Symmetry

    NASA Astrophysics Data System (ADS)

    De Negri Leiva, R. S.; Arciniega-Ceballos, A.; Scheu, B.; Dingwell, D. B.; Sanchez-Sesma, F. J.

    2013-12-01

    We implemented Trefftz's method to simulate wave propagation in a fluid-solid system aimed to represent a magmatic conduit. Assuming axial symmetry, a set of multipoles is used to build a complete system of wave functions for both the solid and the fluid. These functions are solutions of the elastodynamic equations that govern the motions in the fluid and the solid, respectively. The conduit can be closed or open and the exterior elastic domain may be unlimited or with an exterior boundary. In order to find the functions coefficients, boundary conditions (null shear and continuity of pressures and normal velocities) are satisfied in the least squares sense. The impulsive nature of the source is considered using Fourier analysis. Despite the simplicity of the formulation our results display a rich variety of behaviors. In fact, for a uniform infinite cylinder we reproduced the analytical solution. Moreover, this approach allows establishing some important effects of conduit geometry, including changes of sections. Lateral effects and bump resonances are well resolved. We compared our numerical calculations with results obtained from experimental simulations of volcanic explosions in which rapid depressurization induces fragmentation of volcanic rocks. These experiments are performed within a shock-tube apparatus at room temperature and various pressures using Argon (Ar) gas, particles and pumice samples of different porosities, from Popocatepetl volcano. The mechanical system is well characterized and the dynamics of the explosive process is monitored with high precision piezoelectric sensors located at the pipe surface. The combination of analytical and experimental approaches is very useful to understand the seismic wave field of volcanic conduit dynamics.

  16. Parastomal hernias after radical cystectomy and ileal conduit diversion

    PubMed Central

    Donahue, Timothy F.

    2016-01-01

    Parastomal hernia, defined as an "incisional hernia related to an abdominal wall stoma", is a frequent complication after conduit urinary diversion that can negatively impact quality of life and present a clinically significant problem for many patients. Parastomal hernia (PH) rates may be as high as 65% and while many patients are asymptomatic, in some series up to 30% of patients require surgical intervention due to pain, leakage, ostomy appliance problems, urinary obstruction, and rarely bowel obstruction or strangulation. Local tissue repair, stoma relocation, and mesh repairs have been performed to correct PH, however, long-term results have been disappointing with recurrence rates of 30%–76% reported after these techniques. Due to high recurrence rates and the potential morbidity of PH repair, efforts have been made to prevent PH development at the time of the initial surgery. Randomized trials of circumstomal prophylactic mesh placement at the time of colostomy and ileostomy stoma formation have shown significant reductions in PH rates with acceptably low complication profiles. We have placed prophylactic mesh at the time of ileal conduit creation in patients at high risk for PH development and found it to be safe and effective in reducing the PH rates over the short-term. In this review, we describe the clinical and radiographic definitions of PH, the clinical impact and risk factors associated with its development, and the use of prophylactic mesh placement for patients undergoing ileal conduit urinary diversion with the intent of reducing PH rates. PMID:27437533

  17. Tracking dynamics of magma migration in open-conduit systems

    NASA Astrophysics Data System (ADS)

    Valade, Sébastien; Lacanna, Giorgio; Coppola, Diego; Laiolo, Marco; Pistolesi, Marco; Donne, Dario Delle; Genco, Riccardo; Marchetti, Emanuele; Ulivieri, Giacomo; Allocca, Carmine; Cigolini, Corrado; Nishimura, Takeshi; Poggi, Pasquale; Ripepe, Maurizio

    2016-11-01

    Open-conduit volcanic systems are typically characterized by unsealed volcanic conduits feeding permanent or quasi-permanent volcanic activity. This persistent activity limits our ability to read changes in the monitored parameters, making the assessment of possible eruptive crises more difficult. We show how an integrated approach to monitoring can solve this problem, opening a new way to data interpretation. The increasing rate of explosive transients, tremor amplitude, thermal emissions of ejected tephra, and rise of the very-long-period (VLP) seismic source towards the surface are interpreted as indicating an upward migration of the magma column in response to an increased magma input rate. During the 2014 flank eruption of Stromboli, this magma input preceded the effusive eruption by several months. When the new lateral effusive vent opened on the Sciara del Fuoco slope, the effusion was accompanied by a large ground deflation, a deepening of the VLP seismic source, and the cessation of summit explosive activity. Such observations suggest the drainage of a superficial magma reservoir confined between the crater terrace and the effusive vent. We show how this model successfully reproduces the measured rate of effusion, the observed rate of ground deflation, and the deepening of the VLP seismic source. This study also demonstrates the ability of the geophysical network to detect superficial magma recharge within an open-conduit system and to track magma drainage during the effusive crisis, with a great impact on hazard assessment.

  18. Collagen Type I Conduits for the Regeneration of Nerve Defects

    PubMed Central

    Klein, Silvan; Vykoukal, Jody; Felthaus, Oliver; Dienstknecht, Thomas; Prantl, Lukas

    2016-01-01

    To date, reliable data to support the general use of biodegradable materials for bridging nerve defects are still scarce. We present the outcome of nerve regeneration following type I collagen conduit nerve repair in patients with large-diameter nerve gaps. Ten patients underwent nerve repair using a type I collagen nerve conduit. Patients were re-examined at a minimal follow-up of 14.0 months and a mean follow-up of 19.9 months. Regeneration of nerve tissue within the conduits was assessed by nerve conduction velocity (NCV), a static two-point discrimination (S2PD) test, and as disability of arm shoulder and hand (DASH) outcome measure scoring. Quality of life measures including patients’ perceived satisfaction and residual pain were evaluated using a visual analog scale (VAS). No implant-related complications were observed. Seven out of 10 patients reported being free of pain, and the mean VAS was 1.1. The mean DASH score was 17.0. The S2PD was below 6 mm in 40%, between 6 and 10 mm in another 40% and above 10 mm in 20% of the patients. Eight out of 10 patients were satisfied with the procedure and would undergo surgery again. Early treatment correlated with lower DASH score levels. The use of type I collagen in large-diameter gaps in young patients and early treatment presented superior functional outcomes. PMID:28773346

  19. Peripheral nerve regeneration with conduits: use of vein tubes

    PubMed Central

    Sabongi, Rodrigo Guerra; Fernandes, Marcela; dos Santos, João Baptista Gomes

    2015-01-01

    Treatment of peripheral nerve injuries remains a challenge to modern medicine due to the complexity of the neurobiological nerve regenerating process. There is a greater challenge when the transected nerve ends are not amenable to primary end-to-end tensionless neurorraphy. When facing a segmental nerve defect, great effort has been made to develop an alternative to the autologous nerve graft in order to circumvent morbidity at donor site, such as neuroma formation, scarring and permanent loss of function. Tubolization techniques have been developed to bridge nerve gaps and have been extensively studied in numerous experimental and clinical trials. The use of a conduit intends to act as a vehicle for moderation and modulation of the cellular and molecular ambience for nerve regeneration. Among several conduits, vein tubes were validated for clinical application with improving outcomes over the years. This article aims to address the investigation and treatment of segmental nerve injury and draw the current panorama on the use of vein tubes as an autogenous nerve conduit. PMID:26170802

  20. Methods of measuring pumpage through closed-conduit irrigation systems

    USGS Publications Warehouse

    Kjelstrom, L.C.

    1991-01-01

    Methods of measuring volumes of water withdrawn from the Snake River and its tributaries and pumped through closed-conduit irrigation systems were needed for equitable management of and resolution of conflicts over water use. On the basis of evaluations and field tests by researchers from the University of Idaho, Water Resources Research Institute, Moscow, Idaho, an impeller meter was selected to monitor pumpage through closed-conduit systems. In 1988, impeller meters were installed at 20 pumping stations along the Snake River between the Upper Salmon Falls and C.J. Strike Dams. Impeller-derived pumpage data were adjusted if they differed substantially from ultrasonic flow-meter- or current-meter-derived values. Comparisons of pumpage data obtained by ultrasonic flow-meter and current-meter measurements indicated that the ultrasonic flow meter was a reliable means to check operation of impeller meters. The equipment generally performed satisfactorily, and reliable pumpage data could be obtained using impeller meters in closed-conduit irrigation systems. Many pumping stations that divert water from the Snake River for irrigation remain unmeasured; however, regression analyses indicate that total pumpage can be reasonably estimated on the basis of electrical power consumption data, an approximation of total head at a pumping station, and a derived coefficient.

  1. The past, present, and future viscous heat dissipation available for Greenland subglacial conduit formation

    NASA Astrophysics Data System (ADS)

    Mankoff, Kenneth D.; Tulaczyk, Slawek M.

    2017-01-01

    Basal hydrology of the Greenland Ice Sheet (GIS) influences its dynamics and mass balance through basal lubrication and ice-bed decoupling or efficient water removal and ice-bed coupling. Variations in subglacial water pressure through the seasonal evolution of the subglacial hydrological system help control ice velocity. Near the ice sheet margin, large basal conduits are melted by the viscous heat dissipation (VHD) from surface runoff routed to the bed. These conduits may lead to efficient drainage systems that lower subglacial water pressure, increase basal effective stress, and reduce ice velocity. In this study we quantify the energy available for VHD historically at present and under future climate scenarios. At present, 345 km3 of annual runoff delivers 66 GW to the base of the ice sheet per year. These values are already ˜ 50 % more than the historical 1960-1999 value of 46 GW. By 2100 under IPCC AR5 RCP8.5 (RCP4.5) scenarios, 1278 (524) km3 of runoff may deliver 310 (110) GW to the ice sheet base. Hence, the ice sheet may experience a 5-to-7-fold increase in VHD in the near future which will enhance opening of subglacial conduits near the margin and will warm basal ice in the interior. The other significant basal heat source is geothermal heat flux (GHF), which has an estimated value of 36 GW within the present-day VHD area. With increasing surface meltwater penetration to the bed the basal heat budget in the active basal hydrology zone of the GIS will be increasingly dominated by VHD and relatively less sensitive to GHF, which may result in spatial changes in the ice flow field and in its seasonal variability.

  2. Investigating degassing dynamics into the shallow conduit through decompression experiments

    NASA Astrophysics Data System (ADS)

    Spina, Laura; Scheu, Bettina; Cimarelli, Corrado; Dingwell, Donald

    2014-05-01

    The history of bubbles' growth and interaction, as well as their spatial distribution in the shallow conduit, is deeply interconnected with the style of the eruptions. According to the fundamental role played by volatiles in the eruptive process, more effort is required in determining how the key factors of volcanic systems (i.e., magma properties, decompression rate) influence the dynamics of degassing. Therefore, our aim is to provide, through the analysis of decompression experiments on analogue materials, insights on such relations. We performed several decompression experiments with a shock-tube apparatus, and using silicon oil as laboratory-analogue for the magmatic melt. The sample was placed in a transparent autoclave, saturated with Argon for an established amount of time under a fixed pressure (up to a maximum of 10 MPa). Successively it was decompressed to atmospheric conditions, by releasing gas through a control valve. The dynamics of gas exsolution processes were recorded by using pressure sensors and a high speed camera. A range of viscosity values (1, 10, 100, 1000 Pa s) was investigated, for the same decompression path. Furthermore, some experiments were carried out with the addition of glass beads, as analogue to crystals, to the pure liquid. The height of the expanding column was monitored, in conjunction with images recorded during the experiments, and the growth rate of bubbles was measured at different times and depth. Finally, bubble size distribution has been evaluated at various stages for some experiments, in order to achieve a spatial map of the ongoing degassing phenomena. Results allowed us to define different regimes occurring during the decompression, whose features and characteristics are strongly affected by fluid viscosity. Indeed, several degassing phases were observed, from bubbly fluid to the eventual buildup of a more or less "foamy" phase, which ultimately experiences periodical oscillations around an average equilibrium level

  3. Association of pulmonary conduit type and size with durability in infants and young children.

    PubMed

    Poynter, Jeffrey A; Eghtesady, Pirooz; McCrindle, Brian W; Walters, Henry L; Kirshbom, Paul M; Blackstone, Eugene H; Husain, S Adil; Overman, David M; Austin, Erle H; Karamlou, Tara; Lodge, Andrew J; St Louis, James D; Gruber, Peter J; Ziemer, Gerhard; Davies, Ryan R; Jacobs, Jeffrey P; Brown, John W; Williams, William G; Tchervenkov, Christo I; Jacobs, Marshall L; Caldarone, Christopher A

    2013-11-01

    Treatment of congenital heart disease may include placement of a right ventricle to pulmonary artery conduit that requires future surgical replacement. We sought to identify surgeon-modifiable factors associated with durability (defined as freedom from surgical replacement or explantation) of the initial conduit in children less than 2 years of age at initial insertion. Since 2002, 429 infants were discharged from 24 Congenital Heart Surgeons' Society member institutions after initial conduit insertion. Parametric hazard analysis identified factors associated with conduit durability while adjusting for patient characteristics, the institution where the conduit was inserted, and time-dependent interval procedures performed after conduit insertion but before replacement/explantation. In all, 138 conduit replacements (32%) and 3 explantations (1%) were performed. Conduit durability at a median follow-up of 6.0 years (range, 0.1 to 11.7) was 63%. After adjusting for interval procedures and institution, placement of a conduit with smaller z-score was associated with earlier replacement/explantation (p = 0.002). Moreover, conduit durability was substantially reduced with aortic allografts (p = 0.002) and pulmonary allografts (p = 0.03) compared with bovine jugular venous valved conduits (JVVC). The JVVC were 12 mm to 22 mm in diameter at insertion (compared with 6 mm to 20 mm for allografts); therefore, a parametric propensity-adjusted analysis of patients with aortic or pulmonary allografts versus JVVC with diameter of 12 mm or greater was performed, which verified the superior durability of JVVC. Pulmonary conduit type and z-score are associated with late conduit durability independent of the effects of institution and subsequent interval procedures. Surgeons can improve long-term conduit durability by judiciously oversizing, and by selecting a JVVC. Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  4. Long-term outcomes following Medtronic Open Pivot valved conduit.

    PubMed

    Naidoo, Rishendran; Pearse, Bronwyn; Tesar, Peter J; Yap, Su-Ann; Barnett, Adrian G; Fayers, Trevor

    2014-01-01

    Aortic root replacement is a complex procedure, though subsequent modifications of the original Bentall procedure have made surgery more reproducible. The study aim was to examine the outcomes of a modified Bentall procedure, using the Medtronic Open PivotTM valved conduit. Whilst short-term data on the conduit and long-term data on the valve itself are available, little is known of the long-term results with the valved conduit. Patients undergoing aortic root replacement between February 1999 and February 2010, using the Medtronic Open Pivot valved conduit were identified from the prospectively collected Cardiothoracic Register at The Prince Charles Hospital, Brisbane, Australia. All patients were followed up echocardiographically and clinically. The primary end-point was death, and a Cox proportional model was used to identify factors associated.with survival. Secondary end-points were valve-related morbidity (as defined by STS guidelines) and postoperative morbidity. Predictors of morbidity were identified using logistic regression. A total of 246 patients (mean age 50 years) was included in the study. The overall mortality was 12%, with actuarial 10-year survival 79% and a 10-year estimate of valve-related death of 0.04 (95% CI: 0.004, 0.07). Preoperative myocardial infarction (p = 0.004, HR 4.74), urgency of operation (p = 0.038, HR 2.8) and 10% incremental decreases in ejection fraction (p = 0.046, HR 0.69) were predictive of mortality. Survival was also affected by the valve gradients, with a unit increase in peak gradient reducing mortality (p = 0.021, HR 0.93). Valve-related morbidity occurred in 11 patients. Urgent surgery (p <0.001, OR 4.12), aortic dissection (p = 0.015, OR 3.35), calcific aortic stenosis (p = 0.016, OR 2.35) and Marfan syndrome (p 0.009, OR 3.75) were predictive of postoperative morbidity. The reoperation rate was 1.2%. The Medtronic Open Pivot valved conduit is a safe and durable option for aortic root replacement, and is associated

  5. From fractures to conduits: perspectives from three-dimensional simulations

    NASA Astrophysics Data System (ADS)

    Ladd, T.; Starchenko, V.; Marra, C.

    2016-12-01

    Fractures take up only about 1% of the subsurface pore space, but they frequently make the most important contribution to groundwater transport. The increase in permeability due to dissolution of the fracture surfaces gives rise to a number of questions that are important for waste storage systems, sequestration, oil and gas recovery, and dam stability. In numerical simulations, fractures are usually represented by an aperture field, with the three-dimensional equations for flow and transport replaced by averages over the local aperture. We have examined the validity of this approximation by comparing results from aperture-averaged models with results from three-dimensional simulations where the motion of the dissolving surfaces is explicitly accounted for. We find that an aperture-averaged model does not correctly describe flow in the tube-like conduits that develop as the fracture dissolves, nor does it correctly capture the mass transfer from bulk solution to the dissolving surfaces. We have used three-dimensional simulations, with a mesh that conforms to the evolving fracture surfaces, to investigate dissolution beyond the point where reactant first reaches the outlet. We have found that elliptical conduits evolve very early in the dissolution, even prior to breakthrough. They can be nucleated from local enhancements of aperture, from spatially random aperture distributions, or even from variations in the central plane of an otherwise smooth fracture. The shape of the conduit depends on flow rate: at small flow rates they are circular, but expand horizontally into elliptical shapes as the flow rate increases. We have found significant differences between fractures dissolving under constant flow rate (typical of laboratory experiments) and fractures dissolving under a constant pressure drop, possibly coupled with a flow rate limit (more typical of field conditions). Conduits form over a much wider range of flow rates when driven by a pressure difference than

  6. Effects of magma and conduit conditions on transitions between effusive and explosive activity: a numerical modeling approach

    NASA Astrophysics Data System (ADS)

    Carr, B. B.; De'Michieli Vitturi, M.; Clarke, A. B.; Voight, B.

    2013-12-01

    Transitions between effusive and explosive eruptions, common at silicic volcanoes, can occur between distinct eruptive episodes or can occur as changes between effusive and explosive phases within a single episode. The precise causes of these transitions are difficult to determine due to the multitude of mechanisms and variables that can influence fragmentation thresholds. Numerical modeling of magma ascent within a volcanic conduit allows the influence of key variables to be extensively tested. We study the effect of different variables on the mass eruption rate at the vent using a conservative, 1-D, two-phase, steady-state model that allows for lateral gas loss at shallow depths. Several fragmentation criteria are also tested. We are able to generate a number of regime diagrams for a variety of magma and conduit conditions that constrain transitions from effusive to explosive episodes. We show that a transition to explosive activity can occur without changes in the bulk chemistry, crystal volume fraction, or gas mass fraction of the magma. Eruptive style can be controlled by the pressure gradient within the conduit caused by either overpressure in the chamber or varying lava dome size at the vent. Specific results are sensitive to both magma temperature and conduit geometry. It is important that these variables are well constrained when applying this model to different volcanic systems. We apply our model to the recent activity at Merapi Volcano in Indonesia. We constrain model input and output parameters using current petrologic, seismic, and geodetic studies of the Merapi system, and vary critical parameters over reasonable ranges as documented in the literature. Our model is able to reproduce eruption rates observed during both the 2006 effusive and 2010 explosive/effusive eruptions. Our modeling suggests that a combination of chamber overpressure, increased volatile content, and decreased crystal content due to the voluminous injection of new magma into the

  7. Fistula formation between the external iliac artery and ileal conduit following a radical cystoprostatectomy: a rare complication with prewarning signs of haemorrhage

    PubMed Central

    Sukha, Anisha; Smyth, Niamh

    2015-01-01

    A 76-year-old man was admitted with bleeding per-urostomy following a collapse at home. Three weeks prior to the admission, he had undergone a radical cystoprostatectomy and formation of ileal-conduit for an extensive bladder carcinoma. A CT angiogram revealed a possible small source of bleeding within the ileal-conduit itself, which settled with conservative management. However, prior to discharge he developed profuse fresh bleeding from the urostomy, which could not be controlled. The patient underwent an emergency endoscopy of the conduit and laparotomy, which revealed a fistula between the right external iliac artery and the proximal end of the ileal-conduit. The right iliac artery was ligated and an emergency left-to-right femoral-femoral crossover bypass was performed. The right ureter was stented and rediverted through the ileal-conduit and the left ureter was stented at a later date. He unfortunately had a stormy postoperative recovery with further episodes of per-urostomy bleeding and no identified source. PMID:25819824

  8. A Review of Bioactive Release from Nerve Conduits as a Neurotherapeutic Strategy for Neuronal Growth in Peripheral Nerve Injury

    PubMed Central

    Choonara, Yahya E.; Bijukumar, Divya; du Toit, Lisa C.

    2014-01-01

    Peripheral nerve regeneration strategies employ the use of polymeric engineered nerve conduits encompassed with components of a delivery system. This allows for the controlled and sustained release of neurotrophic growth factors for the enhancement of the innate regenerative capacity of the injured nerves. This review article focuses on the delivery of neurotrophic factors (NTFs) and the importance of the parameters that control release kinetics in the delivery of optimal quantities of NTFs for improved therapeutic effect and prevention of dose dumping. Studies utilizing various controlled-release strategies, in attempt to obtain ideal release kinetics, have been reviewed in this paper. Release strategies discussed include affinity-based models, crosslinking techniques, and layer-by-layer technologies. Currently available synthetic hollow nerve conduits, an alternative to the nerve autografts, have proven to be successful in the bridging and regeneration of primarily the short transected nerve gaps in several patient cases. However, current research emphasizes on the development of more advanced nerve conduits able to simulate the effectiveness of the autograft which includes, in particular, the ability to deliver growth factors. PMID:25143934

  9. Construction of nerve guide conduits from cellulose/soy protein composite membranes combined with Schwann cells and pyrroloquinoline quinone for the repair of peripheral nerve defect

    SciTech Connect

    Luo, Lihua; Gan, Li; Liu, Yongming; Tian, Weiqun; Tong, Zan; Wang, Xiong; Huselstein, Celine; Chen, Yun

    2015-02-20

    Regeneration and functional reconstruction of peripheral nerve defects remained a significant clinical challenge. Nerve guide conduits, with seed cells or neurotrophic factors (NTFs), had been widely used to improve the repair and regeneration of injured peripheral nerve. Pyrroloquinoline quinone (PQQ) was an antioxidant that can stimulate nerve growth factors (NGFs) synthesis and accelerate the Schwann cells (SCs) proliferation and growth. In present study, three kinds of nerve guide conduits were constructed: one from cellulose/SPI hollow tube (CSC), another from CSC combined with SCs (CSSC), and the third one from CSSC combined with PQQ (CSSPC), respectively. And then they were applied to bridge and repair the sciatic nerve defect in rats, using autograft as control. Effects of different nerve guide conduits on the nerve regeneration were comparatively evaluated by general analysis, sciatic function index (SFI) and histological analysis (HE and TEM). Newly-formed regenerative nerve fibers were observed and running through the transparent nerve guide conduits 12 weeks after surgery. SFI results indicated that the reconstruction of motor function in CSSPC group was better than that in CSSC and CSC groups. HE images from the cross-sections and longitudinal-sections of the harvested regenerative nerve indicated that regenerative nerve fibers had been formed and accompanied with new blood vessels and matrix materials in the conduits. TEM images also showed that lots of fresh myelinated and non-myelinated nerve fibers had been formed. Parts of vacuolar, swollen and abnormal axons occurred in CSC and CSSC groups, while the vacuolization and swell of axons was the least serious in CSSPC group. These results indicated that CSSPC group had the most ability to repair and reconstruct the nerve structure and functions due to the comprehensive contributions from hollow CSC tube, SCs and PQQ. As a result, the CSSPC may have the potential for the applications as nerve guide

  10. Effect of an Epineurial-Like Biohybrid Nerve Conduit on Nerve Regeneration.

    PubMed

    Hsieh, Shu-Chih; Chang, Chen-Jung; Cheng, Wen-Tung; Tseng, Ting-Chen; Hsu, Shan-hui

    2016-01-01

    A novel approach of making a biomimetic nerve conduit was established by seeding adipose-derived adult stem cells (ADSCs) on the external wall of porous poly(d,l-lactic acid) (PLA) nerve conduits. The PLA conduits were fabricated using gas foaming salt and solvent-nonsolvent phase conversion. We examined the effect of two different porous structures (GS and GL) on ADSC growth and proliferation. The GS conduits had better structural stability, permeability, and porosity, as well as better cell viability at 4, 7, and 10 days. The epineurial-like tissue was grown from ADSC-seeded conduits cultured for 7 days in vitro and then implanted into 10-mm rat sciatic nerve defects for evaluation. The regeneration capacity and functional recovery were evaluated by histological staining, electrophysiology, walking track, and functional gait analysis after 6 weeks of implantation. Experimental data indicated that the autograft and ADSC-seeded GS conduits had better functional recovery than the blank conduits and ADSC-seeded GL conduits. The area of regenerated nerve and number of myelinated axons quantified based on the histology also indicated that the autograft and AGS groups performed better than the other two groups. We suggested that ADSCs may interact with endogenous Schwann cells and release neurotrophic factors to promote peripheral nerve regeneration. The design of the conduit may be critical for producing a biohybrid nerve conduit and to provide an epineurial-like support.

  11. In vitro biocompatibility testing of some synthetic polymers used for the achievement of nervous conduits

    PubMed Central

    Florescu, IP; Coroiu, V; Oancea, A; Lungu, M

    2011-01-01

    Biocompatible synthetic polymers are largely used in the bio–medical domain, tissue engineering and in controlled release of medicines. Polymers can be used in the achievement of cardiac and vascular devices, mammary implants, eye lenses, surgical threads, nervous conduits, adhesives, blood substitutes, etc. Our study was axed on the development of cytotoxicity tests for 3 synthetic polymers, namely polyvinyl alcohol, polyethylene glycol and polyvinyl chloride. These tests targeted to determine the viability and morphology of cells (fibroblasts) that were in indirect contact with the studied polymers. Cell viability achieved for all the studied synthetic polymers allowed their frame in biocompatible material category. Cell morphology did not significantly change, thus accomplishing a new biocompatibility criterion. The degree of biocompatibility of the studied polymers varied. Polyvinyl alcohol presented the highest grade of biocompatibility and polyvinyl chloride placed itself at the lowest limit of biocompatibility. The results achieved allowed the selection of those polymers that (by enhancing their degrees of biocompatibility due to the association with various biopolymers) will be used in the development of new biocompatible materials, useful in nervous conduits manufacture. PMID:22567047

  12. In vitro biocompatibility testing of some synthetic polymers used for the achievement of nervous conduits.

    PubMed

    Mihai, R; Florescu, I P; Coroiu, V; Oancea, A; Lungu, M

    2011-08-15

    Biocompatible synthetic polymers are largely used in the bio-medical domain, tissue engineering and in controlled release of medicines. Polymers can be used in the achievement of cardiac and vascular devices, mammary implants, eye lenses, surgical threads, nervous conduits, adhesives, blood substitutes, etc. Our study was axed on the development of cytotoxicity tests for 3 synthetic polymers, namely polyvinyl alcohol, polyethylene glycol and polyvinyl chloride. These tests targeted to determine the viability and morphology of cells (fibroblasts) that were in indirect contact with the studied polymers. Cell viability achieved for all the studied synthetic polymers allowed their frame in biocompatible material category. Cell morphology did not significantly change, thus accomplishing a new biocompatibility criterion. The degree of biocompatibility of the studied polymers varied. Polyvinyl alcohol presented the highest grade of biocompatibility and polyvinyl chloride placed itself at the lowest limit of biocompatibility. The results achieved allowed the selection of those polymers that (by enhancing their degrees of biocompatibility due to the association with various biopolymers) will be used in the development of new biocompatible materials, useful in nervous conduits manufacture.

  13. Repairing nerve gaps by vein conduits filled with lipoaspirate-derived entire adipose tissue hinders nerve regeneration.

    PubMed

    Papalia, Igor; Raimondo, Stefania; Ronchi, Giulia; Magaudda, Ludovico; Giacobini-Robecchi, Maria G; Geuna, Stefano

    2013-05-01

    In spite of great recent advancements, the definition of the optimal strategy for bridging a nerve defect, especially across long gaps, still remains an open issue since the amount of autologous nerve graft material is limited while the outcome after alternative tubulization techniques is often unsatisfactory. The aim of this study was to investigate a new tubulization technique based on the employment of vein conduits filled with whole subcutaneous adipose tissue obtained by lipoaspiration. In adult rats, a 1cm-long defect of the left median nerve was repaired by adipose tissue-vein-combined conduits and compared with fresh skeletal muscle tissue-vein-combined conduits and autologous nerve grafts made by the excised nerve segment rotated by 180°. Throughout the postoperative period, functional recovery was assessed using the grasping test. Regenerated nerve samples were withdrawn at postoperative month-6 and processed for light and electron microscopy and stereology of regenerated nerve fibers. Results showed that functional recovery was significantly slower in the adipose tissue-enriched group in comparison to both control groups. Light and electron microscopy showed that a large amount of adipose tissue was still present inside the vein conduits at postoperative month-6. Stereology showed that all quantitative morphological predictors analyzed performed significantly worse in the adipose tissue-enriched group in comparison to the two control groups. On the basis of this experimental study in the rat, the use of whole adipose tissue for tissue engineering of peripheral nerves should be discouraged. Pre-treatment of adipose tissue aimed at isolating stromal vascular fraction and/or adipose derived stem/precursor cells should be considered a fundamental requisite for nerve repair. Copyright © 2012 Elsevier GmbH. All rights reserved.

  14. Conduit speed limit promotes formation of explosive `super slugs'

    NASA Astrophysics Data System (ADS)

    Llewellin, E. W.; Burton, M. R.; Mader, H. M.; Polacci, M.

    2014-12-01

    Strombolian activity - characterized by discrete, impulsive explosions - is common at basaltic volcanoes. The explosions are caused by the arrival, at the volcanic vent, of over-pressured `slugs' of magmatic gas, which have ascended the volcanic conduit. We present data from large-scale analogue experiments which reveal a previously-undescribed process which promotes the formation of large, highly over-pressured `super slugs'. We propose that these large slugs may drive the most violent Strombolian eruptions. Experiments were performed at the Large Analogue Volcano Apparatus at Durham University, UK, which comprises a 13m tall, 24cm diameter transparent conduit, surmounting a reservoir of analogue magma held at constant pressure. We simulate a vesiculation event deep in the sub-volcanic plumbing system by fluxing gas into the reservoir. Magma analogues with a range of viscosities are used, giving slug Reynolds numbers in the range 16 to 140,000. At moderate-to-high Reynolds number, we find that the gas rapidly self-organizes to form a conduit-filling lead slug; this slug ascends the column slowly, at a velocity limited by the flux of the falling film of liquid around it. Trailing bubbles, which ascend through the wake of the lead slug, rise much more rapidly. As they catch and coalesce with the lead slug, it grows and becomes increasingly over-pressured. This mechanism causes large slugs to form rapidly and we propose that it underpins the formation of the very large slugs that are responsible for the most explosive strombolian eruptions.

  15. Imaging of platelets in right-sided extracardiac conduits in humans

    SciTech Connect

    Agarwal, K.C.; Wahner, H.W.; Dewanjee, M.K.; Fuster, V.; Puga, F.J.; Danielson, G.K.; Chesebro, J.H.; Feldt, R.H.

    1982-04-01

    As a connection between the systemic venous ventricle and the pulmonary artery, valved Dacron extracardiac conduits have remarkably influenced the surgical approach to many complex congenital heart defects. Obstruction of the conduit, however, can reduce the long-term effectiveness of this corrective procedure. In addition to stenosis of the porcine valve, formation of thick fibrous neointima plays a major role in the pathogenesis of conduit obstruction. The purpose of this study was to determine whether platelet deposition could be demonstrated in these conduits by external imaging with In-111-labeled autologous platelets. After injection of labeled platelets either immediately after operation or on the fifth to eighth post-operative day, imaging was performed by standard procedures. Eight of nine patients had platelet accumulation in the conduit, and treatment with aspirin and dipyridamole caused no recognizable change in platelet deposition. This study demonstrates the feasibility of imaging platelet deposition in Dacron conduits and shows that the pattern of deposition varies with time.

  16. Imaging of platelets in right-sided extracardiac conduits in humans

    SciTech Connect

    Agarwal, K.C.; Wahner, H.W.; Dewanjee, M.K.; Fuster, V.; Puga, F.J.; Danielson, G.K.; Chesebro, J.H.; Feldt, R.H.

    1982-04-01

    As a connection between the systemic venous ventricle and the pulmonary artery, valved Dacron extracardiac conduits have remarkably influenced the surgical approach to many complex congenital heart defects. Obstruction of the conduit, however, can reduce the long-term effectiveness of this corrective procedure. In addition to stenosis of the porcine valve, formation of thick fibrous neointima plays a major role in the pathogenesis of conduit obstruction. The purpose of this study was to determine whether platelet deposition could be demonstrated in these conduits by external imaging with /sup 111/In-labeled autologous platelets. After injection of labeled platelets either immediately after operation or on the fifth to eighth postoperative day, imaging was performed by standard procedures. Eight of nine patients had platelet accumulation in the conduit, and treatment with aspirin and dipyridamole caused no recognizable change in platelet deposition. This study demonstrates the feasibility of imaging platelet deposition in Dacron conduits and shows that the pattern of deposition varies with time.

  17. Device and method for measuring fluid flow in a conduit having a gradual bend

    DOEpatents

    Ortiz, Marcos German; Boucher, Timothy J

    1998-01-01

    A system for measuring fluid flow in a conduit having a gradual bend or arc, and a straight section. The system includes pressure transducers, one or more disposed in the conduit on the outside of the arc, and one disposed in the conduit in a straight section thereof. The pressure transducers measure the pressure of fluid in the conduit at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the conduit. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the conduit elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow.

  18. Migrating quake swarm may indicate magma conduit clog

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2014-03-01

    On 13 January 2006, Augustine Volcano, a towering volcano offshore from the Alaska Peninsula, erupted explosively. In the days leading up to the eruption, a series of explosions and earthquake swarms had warned of the impending activity. On 12 January, 36 hours before the first magmatic explosions, a swarm of 54 earthquakes was detected across the 13-station seismic network on Augustine Island. Analyzing the seismic waves produced by the earthquakes, Buurman and West found that the earthquakes were being triggered from point sources within the magma conduit itself.

  19. Sciatic nerve repair by reinforced nerve conduits made of gelatin-tricalcium phosphate composites.

    PubMed

    Yang, Yi-Chin; Shen, Chiung-Chyi; Cheng, Hsu-Chen; Liu, Bai-Shuan

    2011-02-01

    This study proposes a biodegradable GGT composite nerve guide conduit containing genipin-cross-linked gelatin and tricalcium phosphate (TCP) ceramic particles in peripheral nerve regeneration. The proposed genipin-cross-linked gelatin annexed with TCP ceramic particles (GGT) conduit was dark bluish and round with a rough and compact surface. Water uptake and swelling tests indicated that the hydrated GGT conduit exhibited increased stability with not collapsing or stenosis. The GGT conduit had higher mechanical properties than the genipin-cross-linked gelatin without TCP ceramic particles (GG) conduit and served as a better nerve guide conduit. Cytotoxicity tests revealed that the GGT conduit was not toxic and that it promoted the viability and growth of neural stem cells. The experiments in this study confirmed the effectiveness of the GGT conduit as a guidance channel for repairing a 10-mm gap in rat sciatic nerve. Walking track analysis showed a significantly higher sciatic function index score and better toe spreading development in the GGT group than in the silicone group 8 weeks after implantation. Gross examination revealed that the diameter of the intratubular newly formed nerve fibers in GGT conduits exceeded those in silicone tubes after the implantation period. Histological observations revealed that the morphology and distribution patterns of nerve fibers in the GGT conduits at 8 weeks after implantation were similar to those of normal nerves. The quantitative results indicated the superiority of the conduits over the silicone tubes. Motor functional and histomorphometric assessments demonstrate that the proposed GGT conduit is a suitable candidate for peripheral nerve repair. 2010 Wiley Periodicals, Inc.

  20. APICAL LEFT VENTRICULAR-ABDOMINAL AORTIC COMPOSITE CONDUITS FOR LEFT VENTRICULAR OUTFLOW OBSTRUCTIONS

    PubMed Central

    Cooley, Denton A.; Norman, John C.

    1978-01-01

    Certain problems related to the left ventricular outflow tract are not amenable to conventional surgical methods, but may be solved with the creation of a double outlet left ventricle by using a composite rigid pyrolite left ventricular apex outlet prosthesis and a fabric valve-containing conduit. Low porosity woven Dacron tube grafts are used for the conduit. Twenty-three patients who have undergone apico-aortic bypass with this conduit are reported here, with gratifying results in eighteen. PMID:15216062

  1. Treatment of right ventricle to pulmonary artery conduit stenosis in infants with hypoplastic left heart syndrome.

    PubMed

    Münsterer, Andrea; Kasnar-Samprec, Jelena; Hörer, Jürgen; Cleuziou, Julie; Eicken, Andreas; Malcic, Ivan; Lange, Rüdiger; Schreiber, Christian

    2013-09-01

    To determine the incidence of right ventricle-to-pulmonary artery (RV-PA) conduit stenosis after the Norwood I operation in patients with hypoplastic left heart syndrome (HLHS), and to determine whether the treatment strategy of RV-PA conduit stenosis has an influence on interstage and overall survival. Ninety-six patients had a Norwood operation with RV-PA conduit between 2002 and 2011. Details of reoperations/interventions due to conduit obstruction prior to bidirectional superior cavopulmonary anastomosis (BSCPA) were collected. Overall pre-BSCPA mortality was 17%, early mortality after Norwood, 6%. Early angiography was performed in 34 patients due to desaturation at a median of 8 days after the Norwood operation. Fifteen patients (16%) were diagnosed with RV-PA conduit stenosis that required treatment. The location of the conduit stenosis was significantly different in the patients with non-ringed (proximal) and the patients with ring-enforced conduit (distal), P = 0.004. In 6 patients, a surgical revision of the conduit was performed; 3 of them died prior to BSCPA. Another 6 patients had a stent implantation and 3 were treated with balloon dilatation followed by a BSCPA in the subsequent 2 weeks. All patients who were treated interventionally for RV-PA conduit obstruction had a successful BSCPA. Patients who received a surgical RV-PA conduit revision had a significantly higher interstage (P = 0.044) and overall mortality (P = 0.011) than those who received a stent or balloon dilatation of the stenosis followed by an early BSCPA. RV-PA conduit obstruction after Norwood I procedure in patients with HLHS can be safely and effectively treated by stent implantation, balloon dilatation and early BSCPA. Surgical revision of the RV-PA conduit can be reserved for patients in whom an interventional approach fails, and an early BSCPA is not an option.

  2. Enhancing Peripheral Nerve Regeneration with a Novel Drug Delivering Nerve Conduit

    DTIC Science & Technology

    2014-10-01

    Products 21 7. Participants & Other Collaborating Organizations 22 8. Special Reporting Requirements 23 9. Appendices 24 3... Corning Inc) were also added to the nerve conduit. Figure 2 illustrates the nerve conduit in which the drug (NGF) stored in the orifice between...7525 DLG 7E, Evonik). The PLGA was dissolved in acetone and ethanol and conduits were then formed and emulsified in water. 15µm diffusion holes

  3. Voltage-gated pinning in a magnetic domain-wall conduit

    NASA Astrophysics Data System (ADS)

    Franken, J. H.; Yin, Y.; Schellekens, A. J.; van den Brink, A.; Swagten, H. J. M.; Koopmans, B.

    2013-09-01

    In spintronic devices relying on magnetic domain-wall (DW) motion, robust control over the DW position is required. We use electric-field control of perpendicular magnetic anisotropy to create a voltage-gated pinning site in a microstructured Pt/Co/AlOx DW conduit. A DW pins at the edge of a gate electrode, and the strength of pinning can be tuned linearly and reversibly with an efficiency of 0.22(1) mT/V. This result is supported by a micromagnetic model, taking full account of the anisotropy step at the gate edge, which is directly caused by a change in the electron density due to the choice of material.

  4. Fabrication and evaluation of a biodegradable proanthocyanidin-crosslinked gelatin conduit in peripheral nerve repair.

    PubMed

    Liu, Bai-Shuan

    2008-12-15

    This study proposed a novel and biodegradable nerve guide conduit in its applicability to peripheral nerve regeneration. A naturally occurring proanthocyanidin (PA) was selected as a cross-linking reagent in preparing the PA-crosslinked gelatin (PCG) conduit. Experimental results indicate that 5 wt % of PA was optimal in the complete cross-linking reaction in the PCG conduit. The PCG conduit was brownish and round with a rough outer surface whereas its inner lumen was smooth. The cross-linked networks of the PCG conduit resisted enzymatic hydrolysis under in vitro degradation studies. PA and gelatin were released from the soaked PCG conduit. During the release phase, the concentrations of PA, gelatin, and PCG-soaking solutions were not only nontoxic but also promoted the viability and growth of Schwann cells. The PCG conduit more effectively supported cell attachment and growth. The effectiveness of the PCG conduit as a guidance channel was studied when it was used to repair a 10 mm gap in the rat sciatic nerve. Throughout the 8-week experimental period, the peak amplitude and area under the muscle action potential curve both increased with the recovery period. Histological observations revealed that various regenerated nerve fibers crossed through and beyond the gap region. These results suggest that the PCG conduit can be a candidate for peripheral nerve repair. 2008 Wiley Periodicals, Inc.

  5. Environmental tracers as indicators of karst conduits in groundwater in South Dakota, USA

    USGS Publications Warehouse

    Long, A.J.; Sawyer, J.F.; Putnam, L.D.

    2008-01-01

    Environmental tracers sampled from the carbonate Madison aquifer on the eastern flank of the Black Hills, South Dakota, USA indicated the approximate locations of four major karst conduits. Contamination issues are a major concern because these conduits are characterized by direct connections to sinking streams, high groundwater velocities, and proximity to public water supplies. Objectives of the study were to estimate approximate conduit locations and assess possible anthropogenic influences associated with conduits. Anomalies of young groundwater based on chlorofluorocarbons (CFCs), tritium, and electrical conductivity (EC) indicated fast moving, focused flow and thus the likely presence of conduits. ??18O was useful for determining sources of recharge for each conduit, and nitrate was a useful tracer for assessing flow paths for anthropogenic influences. Two of the four conduits terminate at or near a large spring complex. CFC apparent ages ranged from 15 years near conduits to >50 years in other areas. Nitrate-N concentrations >0.4 mg/L in groundwater were associated with each of the four conduits compared with concentrations ranging from <0.1 to 0.4 mg/L in other areas. These higher nitrate-N concentrations probably do not result from sinking streams but rather from other areas of infiltration. ?? Springer-Verlag 2007.

  6. 3D-engineering of Cellularized Conduits for Peripheral Nerve Regeneration

    NASA Astrophysics Data System (ADS)

    Hu, Yu; Wu, Yao; Gou, Zhiyuan; Tao, Jie; Zhang, Jiumeng; Liu, Qianqi; Kang, Tianyi; Jiang, Shu; Huang, Siqing; He, Jiankang; Chen, Shaochen; Du, Yanan; Gou, Maling

    2016-08-01

    Tissue engineered conduits have great promise for bridging peripheral nerve defects by providing physical guiding and biological cues. A flexible method for integrating support cells into a conduit with desired architectures is wanted. Here, a 3D-printing technology is adopted to prepare a bio-conduit with designer structures for peripheral nerve regeneration. This bio-conduit is consisted of a cryopolymerized gelatin methacryloyl (cryoGelMA) gel cellularized with adipose-derived stem cells (ASCs). By modeling using 3D-printed “lock and key” moulds, the cryoGelMA gel is structured into conduits with different geometries, such as the designed multichannel or bifurcating and the personalized structures. The cryoGelMA conduit is degradable and could be completely degraded in 2-4 months in vivo. The cryoGelMA scaffold supports the attachment, proliferation and survival of the seeded ASCs, and up-regulates the expression of their neurotrophic factors mRNA in vitro. After implanted in a rat model, the bio-conduit is capable of supporting the re-innervation across a 10 mm sciatic nerve gap, with results close to that of the autografts in terms of functional and histological assessments. The study describes an indirect 3D-printing technology for fabricating cellularized designer conduits for peripheral nerve regeneration, and could lead to the development of future nerve bio-conduits for clinical use.

  7. A silk sericin/silicone nerve guidance conduit promotes regeneration of a transected sciatic nerve.

    PubMed

    Xie, Hongjian; Yang, Wen; Chen, Jianghai; Zhang, Jinxiang; Lu, Xiaochen; Zhao, Xiaobo; Huang, Kun; Li, Huili; Chang, Panpan; Wang, Zheng; Wang, Lin

    2015-10-28

    Peripheral nerve gap defects lead to significant loss of sensory or motor function. Tissue engineering has become an important alternative to nerve repair. Sericin, a major component of silk, is a natural protein whose value in tissue engineering has just begun to be explored. Here, the first time use of sericin in vivo is reported as a long-term implant for peripheral nerve regeneration. A sericin nerve guidance conduit is designed and fabricated. This conduit is highly porous with mechanical strength matching peripheral nerve tissue. It supports Schwann cell proliferation and is capable of up-regulating the transcription of glial cell derived neurotrophic factor and nerve growth factor in Schwann cells. The sericin conduit wrapped with a silicone conduit (sericin/silicone double conduits) is used for bridging repair of a 5 mm gap in a rat sciatic nerve transection model. The sericin/silicone double conduits achieve functional recovery comparable to that of autologous nerve grafting as evidenced by drastically improved nerve function and morphology. Importantly, this improvement is mainly attributed to the sericin conduit as the silicone conduit alone only produces marginal functional recovery. This sericin/silicone-double-conduit strategy offers an efficient and valuable alternative to autologous nerve grafting for repairing damaged peripheral nerve.

  8. 3D-engineering of Cellularized Conduits for Peripheral Nerve Regeneration

    PubMed Central

    Hu, Yu; Wu, Yao; Gou, Zhiyuan; Tao, Jie; Zhang, Jiumeng; Liu, Qianqi; Kang, Tianyi; Jiang, Shu; Huang, Siqing; He, Jiankang; Chen, Shaochen; Du, Yanan; Gou, Maling

    2016-01-01

    Tissue engineered conduits have great promise for bridging peripheral nerve defects by providing physical guiding and biological cues. A flexible method for integrating support cells into a conduit with desired architectures is wanted. Here, a 3D-printing technology is adopted to prepare a bio-conduit with designer structures for peripheral nerve regeneration. This bio-conduit is consisted of a cryopolymerized gelatin methacryloyl (cryoGelMA) gel cellularized with adipose-derived stem cells (ASCs). By modeling using 3D-printed “lock and key” moulds, the cryoGelMA gel is structured into conduits with different geometries, such as the designed multichannel or bifurcating and the personalized structures. The cryoGelMA conduit is degradable and could be completely degraded in 2-4 months in vivo. The cryoGelMA scaffold supports the attachment, proliferation and survival of the seeded ASCs, and up-regulates the expression of their neurotrophic factors mRNA in vitro. After implanted in a rat model, the bio-conduit is capable of supporting the re-innervation across a 10 mm sciatic nerve gap, with results close to that of the autografts in terms of functional and histological assessments. The study describes an indirect 3D-printing technology for fabricating cellularized designer conduits for peripheral nerve regeneration, and could lead to the development of future nerve bio-conduits for clinical use. PMID:27572698

  9. Evaluation of Gastric Conduit Perfusion During Esophagectomy with Indocyanine Green Fluorescence Imaging.

    PubMed

    Schlottmann, Francisco; Patti, Marco G

    2017-08-17

    Anastomotic leakage is a determining factor of morbidity and mortality after an esophagectomy. An adequate blood supply of the gastric conduit is vital to prevent this complication. We aimed to determine the feasibility and usefulness of indocyanine green (ICG) fluorescence imaging to evaluate the gastric conduit perfusion during an esophagectomy. Patients with distal esophageal cancer or esophagogastric junction cancer scheduled for esophagectomy were enrolled in this study. After pulling up the gastric conduit into the chest and before performing the anastomosis, 5 mg of ICG was injected as a bolus. Visual assessment of the blood supply of the gastric conduit was compared with the ICG fluorescence imaging pattern of perfusion. Five patients were included in this study. Hybrid Ivor-Lewis esophagectomy (laparoscopic abdomen and right thoracotomy) was performed in all cases. In all patients, visual assessment of the perfusion of the stomach determined that the conduit was well perfused. In two patients (40%), ICG fluorescence showed an inadequate blood supply of the conduit's tip. Resection of the devitalized portion of the conduit was performed in these two patients. No anastomotic leaks were recorded, and all patients had an uneventful postoperative course. Visual assessment of the gastric conduit may underestimate perfusion and inadequate blood supply. ICG fluorescence imaging is a promising tool to determine the gastric conduit perfusion during an esophagectomy. Prospective studies with larger series are warranted to confirm the usefulness of ICG fluorescence imaging during an esophagectomy.

  10. Construction of nerve guide conduits from cellulose/soy protein composite membranes combined with Schwann cells and pyrroloquinoline quinone for the repair of peripheral nerve defect.

    PubMed

    Luo, Lihua; Gan, Li; Liu, Yongming; Tian, Weiqun; Tong, Zan; Wang, Xiong; Huselstein, Celine; Chen, Yun

    2015-02-20

    Regeneration and functional reconstruction of peripheral nerve defects remained a significant clinical challenge. Nerve guide conduits, with seed cells or neurotrophic factors (NTFs), had been widely used to improve the repair and regeneration of injured peripheral nerve. Pyrroloquinoline quinone (PQQ) was an antioxidant that can stimulate nerve growth factors (NGFs) synthesis and accelerate the Schwann cells (SCs) proliferation and growth. In present study, three kinds of nerve guide conduits were constructed: one from cellulose/SPI hollow tube (CSC), another from CSC combined with SCs (CSSC), and the third one from CSSC combined with PQQ (CSSPC), respectively. And then they were applied to bridge and repair the sciatic nerve defect in rats, using autograft as control. Effects of different nerve guide conduits on the nerve regeneration were comparatively evaluated by general analysis, sciatic function index (SFI) and histological analysis (HE and TEM). Newly-formed regenerative nerve fibers were observed and running through the transparent nerve guide conduits 12 weeks after surgery. SFI results indicated that the reconstruction of motor function in CSSPC group was better than that in CSSC and CSC groups. HE images from the cross-sections and longitudinal-sections of the harvested regenerative nerve indicated that regenerative nerve fibers had been formed and accompanied with new blood vessels and matrix materials in the conduits. TEM images also showed that lots of fresh myelinated and non-myelinated nerve fibers had been formed. Parts of vacuolar, swollen and abnormal axons occurred in CSC and CSSC groups, while the vacuolization and swell of axons was the least serious in CSSPC group. These results indicated that CSSPC group had the most ability to repair and reconstruct the nerve structure and functions due to the comprehensive contributions from hollow CSC tube, SCs and PQQ. As a result, the CSSPC may have the potential for the applications as nerve guide

  11. Aspirin changes the secretion rate and amino acid composition of human small intestinal mucin in subjects with ileal conduits.

    PubMed

    Roberton, A M; Rabel, B; Stubbs, L; Tasman-Jones, C; Lee, S P

    1996-10-01

    The effect of aspirin on the rate of secretion and amino acid composition of human ileal mucin was studied, using subjects with ileal conduits as a model system in which mucin secreted from the ileal conduit tissue is flushed out in the urine and can be measured and analysed. Aspirin (600 mg per day, administered orally) increased the daily mucin output by 37-104% in subjects by days 3 or 4, but thereafter the mucin output declined to below the baseline level by day 10. Mucin samples, purified from the ileal conduit urine during the control period and during aspirin administration, were compared. There were no discernible changes in the degree of polymerisation or the density, but during aspirin administration the amino acid composition was significantly changed, and in particular threonine and proline were enriched. One possible explanation, consistent with the compositional analyses, is that the N- and C-terminal regions of the mucin subunits have been cleaved off and lost during aspirin administration. The observed changes in mucin secretion may have implications for the mechanism of the toxic effects of aspirin on the small intestine by altering the barrier properties of the mucus layer.

  12. Development of a new lacrimal drainage conduit using POSS nanocomposite.

    PubMed

    Chaloupka, Karla; Motwani, Meghna; Seifalian, Alexander Marcus

    2011-01-01

    Lacrimal surgery in cases of severely obstructed or missing canalicular ducts is highly challenging. In these cases, the placement of a bypass tube is currently the only option to restore the drainage of tears into the nose and reduce the symptomatic watery eye. Different approaches to achieve functional drainage have been tried using blood vessels or artificial implants. The implantation of the rigid Lester Jones tube is, since its introduction in the late 1960s, the gold standard. The functional success is satisfactory. However, complication rates are high and remain, even with many modifications of the original design, a major problem. These complications include mainly the displacement and blockage of the tube, requiring regular checkups, as well as irritation of the surrounding tissue including the nose and the eye. The objective of this study was to develop a new lacrimal duct conduit (LDC) to restore structural and functional integrity of the lacrimal drainage system. The conduit is constructed with a novel polymer, polyhedral oligomeric silsesquioxane-poly(carbonate-urea)urethane (POSS-PCU), that offers biocompatibility. We exploit nanotopography to evade the problems associated with current applications. A number of extrusion techniques were investigated for this purpose: ultrasonic atomization spraying, electrohydrodynamic atomization spraying/spinning, extrusion-coagulation, and high-pressure coagulation by autoclave and casting. Finally, the coagulation and cast technique were selected to construct an LDC superior to its predecessors, and its advantages highlighted.

  13. Exploring Ultimate Water Capillary Evaporation in Nanoscale Conduits.

    PubMed

    Li, Yinxiao; Alibakhshi, Mohammad Amin; Zhao, Yihong; Duan, Chuanhua

    2017-08-09

    Capillary evaporation in nanoscale conduits is an efficient heat/mass transfer strategy that has been widely utilized by both nature and mankind. Despite its broad impact, the ultimate transport limits of capillary evaporation in nanoscale conduits, governed by the evaporation/condensation kinetics at the liquid-vapor interface, have remained poorly understood. Here we report experimental study of the kinetic limits of water capillary evaporation in two dimensional nanochannels using a novel hybrid channel design. Our results show that the kinetic-limited evaporation fluxes break down the limits predicated by the classical Hertz-Knudsen equation by an order of magnitude, reaching values up to 37.5 mm/s with corresponding heat fluxes up to 8500 W/cm(2). The measured evaporation flux increases with decreasing channel height and relative humidity but decreases as the channel temperature decreases. Our findings have implications for further understanding evaporation at the nanoscale and developing capillary evaporation-based technologies for both energy- and bio-related applications.

  14. Acoustic resonance in the combustion conduits of a steam locomotive

    SciTech Connect

    Ziada, S.; Oengoeren, A.; Vogel, H.H.

    1996-12-01

    The sound emission of a modern, oil fired steam rack locomotive increased sharply when the locomotive speed exceeded the design value of 12 km/hr. The results of pressure and noise measurements, together with an acoustical model of the combustion conduits indicated that the acoustic resonance modes of the combustion conduits are excited by the pressure pulsations generated by the exhaust from the steam cylinders at multiples of the piston frequency. Additionally, when the acoustic resonance is initiated, the resulting pulsations trigger the flame instability of the oil burners which, in turn, enhances the resonance. By means of the acoustical model, a Helmholtz resonator has been designed and optimized to reduce the acoustic response such that it does not excite the flame instability. A second set of measurements, after installing the resonator, has shown a reduction in the noise level by an amount exceeding 21 dBA. The paper focuses upon the identification of the excitation source and the implementation of the countermeasure which are of interest to other applications involving combustion oscillations.

  15. Bio-Valsalva prosthesis: 'new' conduit for 'old' patients.

    PubMed

    Di Bartolomeo, Roberto; Botta, Luca; Leone, Alessandro; Pilato, Emanuele; Martin-Suarez, Sofia; Bacchini, Massimo; Pacini, Davide

    2008-12-01

    A new bio-prosthetic valved conduit (Bio-Valsalva) has recently been introduced into surgical practice in order to offer a valid option for elderly patients undergoing composite aortic root replacement. The conduit is made up of a stentless porcine valve (elan valve) pre-sewn inside a triple layer Valsalva prosthesis and it is entirely preserved in a glutaraldehyde solution. In our Department, 21 patients (16 males, mean age 67.8+/-5.5 years) underwent aortic root replacement using the Bio-Valsalva prosthesis. Composite root replacement was extended to the hemiarch in three cases while a complete arch replacement was performed in two patients. Type A aortic dissection was present in two cases while a bicuspid aortic valve was detected in eight patients. In-hospital mortality was 4.7% (1 patient). Re-thoracotomy for bleeding was performed in one case. The median in-hospital stay was 12 days. The median follow-up was six months and is 100% complete. There were no re-operations or structural deterioration during this early phase of observation. The Bio-Valsalva graft, readily available in different sizes, demonstrates ease of implantability and shows good haemostatic characteristics. More patients and a longer follow-up are necessary to confirm the advantages of this graft.

  16. Conduit for high temperature transfer of molten semiconductor crystalline material

    NASA Technical Reports Server (NTRS)

    Fiegl, George (Inventor); Torbet, Walter (Inventor)

    1983-01-01

    A conduit for high temperature transfer of molten semiconductor crystalline material consists of a composite structure incorporating a quartz transfer tube as the innermost member, with an outer thermally insulating layer designed to serve the dual purposes of minimizing heat losses from the quartz tube and maintaining mechanical strength and rigidity of the conduit at the elevated temperatures encountered. The composite structure ensures that the molten semiconductor material only comes in contact with a material (quartz) with which it is compatible, while the outer layer structure reinforces the quartz tube, which becomes somewhat soft at molten semiconductor temperatures. To further aid in preventing cooling of the molten semiconductor, a distributed, electric resistance heater is in contact with the surface of the quartz tube over most of its length. The quartz tube has short end portions which extend through the surface of the semiconductor melt and which are lef bare of the thermal insulation. The heater is designed to provide an increased heat input per unit area in the region adjacent these end portions.

  17. Documentation of a Conduit Flow Process (CFP) for MODFLOW-2005

    USGS Publications Warehouse

    Shoemaker, W. Barclay; Kuniansky, Eve L.; Birk, Steffen; Bauer, Sebastian; Swain, Eric D.

    2007-01-01

    This report documents the Conduit Flow Process (CFP) for the modular finite-difference ground-water flow model, MODFLOW-2005. The CFP has the ability to simulate turbulent ground-water flow conditions by: (1) coupling the traditional ground-water flow equation with formulations for a discrete network of cylindrical pipes (Mode 1), (2) inserting a high-conductivity flow layer that can switch between laminar and turbulent flow (Mode 2), or (3) simultaneously coupling a discrete pipe network while inserting a high-conductivity flow layer that can switch between laminar and turbulent flow (Mode 3). Conduit flow pipes (Mode 1) may represent dissolution or biological burrowing features in carbonate aquifers, voids in fractured rock, and (or) lava tubes in basaltic aquifers and can be fully or partially saturated under laminar or turbulent flow conditions. Preferential flow layers (Mode 2) may represent: (1) a porous media where turbulent flow is suspected to occur under the observed hydraulic gradients; (2) a single secondary porosity subsurface feature, such as a well-defined laterally extensive underground cave; or (3) a horizontal preferential flow layer consisting of many interconnected voids. In this second case, the input data are effective parameters, such as a very high hydraulic conductivity, representing multiple features. Data preparation is more complex for CFP Mode 1 (CFPM1) than for CFP Mode 2 (CFPM2). Specifically for CFPM1, conduit pipe locations, lengths, diameters, tortuosity, internal roughness, critical Reynolds numbers (NRe), and exchange conductances are required. CFPM1, however, solves the pipe network equations in a matrix that is independent of the porous media equation matrix, which may mitigate numerical instability associated with solution of dual flow components within the same matrix. CFPM2 requires less hydraulic information and knowledge about the specific location and hydraulic properties of conduits, and turbulent flow is approximated by

  18. Frictional melting dynamics in the upper conduit: A chemical answer to a complex physical question

    NASA Astrophysics Data System (ADS)

    Henton De Angelis, S.; Lavallee, Y.; Kendrick, J. E.; Hornby, A.; von Aulock, F. W.; Clesham, S.; Hirose, T.; Perugini, D.

    2013-12-01

    During volcanic eruptions the generation of frictional heat along the walls of the shallow conduit leads to melting of the rocks along the slip interface. Frictional melting has previously been described as a process out of thermodynamic equilibrium, but upon slip and mingling of the melt batches, homogeneity can be achieved, and may have an h important rheological control on the dynamics of slip. To test melt homogenization in the frictional melt zones of volcanic conduits we performed constant-rate slip experiments under controlled stress conditions using a high-velocity rotary shear apparatus. Volcanic dome samples from three different volcanoes (Volcán De Colima, Soufrière Hills Volcano and Santiaguito Volcano) were investigated. Each sample was subjected to a stress of 1 MPa and slip rate of 1 m/s. For each sample set 5 experiments were conducted: 1) experiment stopped at the onset of melting; 2) experiment stopped on the formation of a full melt layer; 3) experiment stopped after 5m of slip at steady state conditions; 4) experiment stopped after 10m of slip at steady state conditions; 5) experiment stopped after 15m of slip at steady state conditions. We analyzed the resulting proto-melt zones using micron sized X-ray spectroscopy in the high-brightness synchrotron beamline I18 (at Diamond Light Source UK). Particular focus was given to the concentration variance analysis of Rare Earth Elements as their mobilities can be used to precisely quantify the degree and timescale of homogenisation involved during frictional melting. This study refines our understanding of the chemical process of melting and mixing which carry important consequences for the rheological control on the physical dynamics of slip.

  19. Conduit dynamics in transitional rhyolitic activity recorded by tuffisite vein textures from the 2008-2009 Chaitén eruption

    NASA Astrophysics Data System (ADS)

    Saubin, Elodie; Tuffen, Hugh; Gurioli, Lucia; Owen, Jacqueline; Castro, Jonathan; Berlo, Kim; McGowan, Ellen; Schipper, C.; Wehbe, Katia

    2016-05-01

    The mechanisms of hazardous silicic eruptions are controlled by complex, poorly-understood conduit processes. Observations of recent Chilean rhyolite eruptions have revealed the importance of hybrid activity, involving simultaneous explosive and effusive emissions from a common vent. Such behaviour hinges upon the ability of gas to decouple from magma in the shallow conduit. Tuffisite veins are increasingly suspected to be a key facilitator of outgassing, as they repeatedly provide a transient permeable escape route for volcanic gases. Intersection of foam domains by tuffisite veins appears critical to efficient outgassing. However, knowledge is currently lacking into textural heterogeneities within shallow conduits, their relationship with tuffisite vein propagation, and the implications for fragmentation and degassing processes. Similarly, the magmatic vesiculation response to upper conduit pressure perturbations, such as those related to the slip of dense magma plugs, remains largely undefined. Here we provide a detailed characterization of an exceptionally large tuffisite vein within a rhyolitic obsidian bomb ejected during transitional explosive-effusive activity at Chaitén, Chile in May 2008. Vein textures and chemistry provide a time-integrated record of the invasion of a dense upper conduit plug by deeper fragmented magma. Quantitative textural analysis reveals diverse vesiculation histories of various juvenile clast types. Using vesicle size distributions, bubble number densities, zones of diffusive water depletion, and glass H2O concentrations, we propose a multi-step degassing/fragmentation history, spanning deep degassing to explosive bomb ejection. Rapid decompression events of ~3-4 MPa are associated with fragmentation of foam and dense magma at ~200-350 metres depth in the conduit, permitting vertical gas and pyroclast mobility over hundreds of metres. Permeable pathway occlusion in the dense conduit plug by pyroclast accumulation and sintering

  20. Manufacture of porous biodegradable polymer conduits by an extrusion process for guided tissue regeneration

    NASA Technical Reports Server (NTRS)

    Widmer, M. S.; Gupta, P. K.; Lu, L.; Meszlenyi, R. K.; Evans, G. R.; Brandt, K.; Savel, T.; Gurlek, A.; Patrick, C. W. Jr; Mikos, A. G.; hide

    1998-01-01

    We have fabricated porous, biodegradable tubular conduits for guided tissue regeneration using a combined solvent casting and extrusion technique. The biodegradable polymers used in this study were poly(DL-lactic-co-glycolic acid) (PLGA) and poly(L-lactic acid) (PLLA). A polymer/salt composite was first prepared by a solvent casting process. After drying, the composite was extruded to form a tubular construct. The salt particles in the construct were then leached out leaving a conduit with an open-pore structure. PLGA was studied as a model polymer to analyze the effects of salt weight fraction, salt particle size, and processing temperature on porosity and pore size of the extruded conduits. The porosity and pore size were found to increase with increasing salt weight fraction. Increasing the salt particle size increased the pore diameter but did not affect the porosity. High extrusion temperatures decreased the pore diameter without altering the porosity. Greater decrease in molecular weight was observed for conduits manufactured at higher temperatures. The mechanical properties of both PLGA and PLLA conduits were tested after degradation in vitro for up to 8 weeks. The modulus and failure strength of PLLA conduits were approximately 10 times higher than those of PLGA conduits. Failure strain was similar for both conduits. After degradation for 8 weeks, the molecular weights of the PLGA and PLLA conduits decreased to 38% and 43% of the initial values, respectively. However, both conduits maintained their shape and did not collapse. The PLGA also remained amorphous throughout the time course, while the crystallinity of PLLA increased from 5.2% to 11.5%. The potential of seeding the conduits with cells for transplantation or with biodegradable polymer microparticles for drug delivery was also tested with dyed microspheres. These porous tubular structures hold great promise for the regeneration of tissues which require tubular scaffolds such as peripheral nerve

  1. Manufacture of porous biodegradable polymer conduits by an extrusion process for guided tissue regeneration.

    PubMed

    Widmer, M S; Gupta, P K; Lu, L; Meszlenyi, R K; Evans, G R; Brandt, K; Savel, T; Gurlek, A; Patrick, C W; Mikos, A G

    1998-11-01

    We have fabricated porous, biodegradable tubular conduits for guided tissue regeneration using a combined solvent casting and extrusion technique. The biodegradable polymers used in this study were poly(DL-lactic-co-glycolic acid) (PLGA) and poly(L-lactic acid) (PLLA). A polymer/salt composite was first prepared by a solvent casting process. After drying, the composite was extruded to form a tubular construct. The salt particles in the construct were then leached out leaving a conduit with an open-pore structure. PLGA was studied as a model polymer to analyze the effects of salt weight fraction, salt particle size, and processing temperature on porosity and pore size of the extruded conduits. The porosity and pore size were found to increase with increasing salt weight fraction. Increasing the salt particle size increased the pore diameter but did not affect the porosity. High extrusion temperatures decreased the pore diameter without altering the porosity. Greater decrease in molecular weight was observed for conduits manufactured at higher temperatures. The mechanical properties of both PLGA and PLLA conduits were tested after degradation in vitro for up to 8 weeks. The modulus and failure strength of PLLA conduits were approximately 10 times higher than those of PLGA conduits. Failure strain was similar for both conduits. After degradation for 8 weeks, the molecular weights of the PLGA and PLLA conduits decreased to 38% and 43% of the initial values, respectively. However, both conduits maintained their shape and did not collapse. The PLGA also remained amorphous throughout the time course, while the crystallinity of PLLA increased from 5.2% to 11.5%. The potential of seeding the conduits with cells for transplantation or with biodegradable polymer microparticles for drug delivery was also tested with dyed microspheres. These porous tubular structures hold great promise for the regeneration of tissues which require tubular scaffolds such as peripheral nerve

  2. Linear permeability evolution of expanding conduits due to feedback between flow and fast phase change

    NASA Astrophysics Data System (ADS)

    Wang, Lichun; Cardenas, M. Bayani

    2017-05-01

    Conduits are ubiquitous and critical pathways for many fluids relevant for geophysical processes such as magma, water, and gases. Predicting flow through conduits is challenging when the conduit geometry coevolves with the flow. We theoretically show that the permeability (k) of a conduit whose walls are eroding due to fast phase change increases linearly with time because of a self-reinforcing mechanism. This simple result is surprising given complex feedbacks between flow, transport, and phase change. The theory is congruent with previous experimental observations of fracture dissolution in calcite. Supporting computational fracture dissolution experiments showed that k only slightly increases until the dissolution front reaches the narrowest conduit constriction, after which the linear evolution of k manifests. The theory holds across multiple scales and a broad range of Peclet and Damkohler numbers and thus advances the prediction of dynamic mass fluxes through expanding conduits in various geologic and environmental settings.Plain Language SummaryGeological <span class="hlt">conduits</span> are ubiquitous present in the subsurface. In many situations, these <span class="hlt">conduits</span> may enlarge through time due to erosion of its walls by dissolution and melting. This leads to strongly coupled flow and reactive transport processes where the flow dictates the wall's erosion and vice versa. As the <span class="hlt">conduit</span> expands, so does its permeability and thus flow. Thus, predicting fluid flow and relevant transport processes through expanding <span class="hlt">conduits</span> is challenging. In this study, we presented a theory for the linear time dependence of permeability for expanding <span class="hlt">conduits</span>. The theory is congruent with previous observations from fracture dissolution in calcite. An additional series of our own computational experiments also aligns with the theory. The theory will be of interest to geoscientists and engineers in many fields such as hydrology, glaciology, and petroleum</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994E%26PSL.121..137M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994E%26PSL.121..137M"><span>Erosion processes in volcanic <span class="hlt">conduits</span> and application to the AD 79 eruption of Vesuvius</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Macedonio, Giovanni; Dobran, Flavio; Neri, Augusto</p> <p>1994-01-01</p> <p>The flow of gas, magma and pyroclasts through a volcanic <span class="hlt">conduit</span> produces erosion of the <span class="hlt">conduit</span> wall. Erosion may be produced by the impact of pyroclasts on the <span class="hlt">conduit</span> wall, fluid shear stress at the wall, <span class="hlt">conduit</span> wall collapse, and volcanic tremor. Using a two-phase flow non-equilibrium model of magma ascent along the volcanic <span class="hlt">conduits</span> demonstrated that the erosion due to the impact of particles on the wall can occur only above the magma fragmentation level of the <span class="hlt">conduit</span> where the particles or pyroclasts remove the wall material by an abrasion process. This abrasion process was found to be the largest near the <span class="hlt">conduit</span> exit where the gas-magma velocities are the largest. The erosion due to the fluid shear stress at the wall can be produced along the entire length of a <span class="hlt">conduit</span>, depending on the wall roughness and yield strength of wall rocks. This shear stress is the largest near the magma fragmentation level where the gas-magma viscosity and velocity gradients are very large. The collapse of <span class="hlt">conduit</span> wall due to the difference between the gas-magma and lithostatic pressures can occur below and above the magma fragmentation level, causing the production of lithics directly when the wall collapses inward, and indirectly when the wall collapses outward. The effectiveness of different erosion mechanisms was tested with the magma characteristics, <span class="hlt">conduit</span> geometry, and wall rock properties pertaining to the AD 79 eruption of Vesuvius. It was found that during the white and gray magma plinian eruption phases the lithics should have come from the deep as well as from the shallow regions of the <span class="hlt">conduit</span>. The conclusions from erosion modeling are also consistent with the limited field data whereby the gray magma phase deposits are associated with larger lithic content and larger proportion of deep limestone fragments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Litho.272..261R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Litho.272..261R"><span>Silicic magma differentiation in ascent <span class="hlt">conduits</span>. Experimental constraints</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rodríguez, Carmen; Castro, Antonio</p> <p>2017-02-01</p> <p>Crystallization of water-bearing silicic magmas in a dynamic thermal boundary layer is reproduced experimentally by using the intrinsic thermal gradient of piston-cylinder assemblies. The standard AGV2 andesite under water-undersaturated conditions is set to crystallize in a dynamic thermal gradient of about 35 °C/mm in 10 mm length capsules. In the hotter area of the capsule, the temperature is initially set at 1200 °C and decreases by programmed cooling at two distinct rates of 0.6 and 9.6 °C/h. Experiments are conducted in horizontally arranged assemblies in a piston cylinder apparatus to avoid any effect of gravity settling and compaction of crystals in long duration runs. The results are conclusive about the effect of water-rich fluids that are expelled out the crystal-rich zone (mush), where water saturation is reached by second boiling in the interstitial liquid. Expelled fluids migrate to the magma ahead of the solidification front contributing to a progressive enrichment in the fluxed components SiO2, K2O and H2O. The composition of water-rich fluids is modelled by mass balance using the chemical composition of glasses (quenched melt). The results are the basis for a model of granite magma differentiation in thermally-zoned <span class="hlt">conduits</span> with application of in-situ crystallization equations. The intriguing textural and compositional features of the typical autoliths, accompanying granodiorite-tonalite batholiths, can be explained following the results of this study, by critical phenomena leading to splitting of an initially homogeneous magma into two magma systems with sharp boundaries. Magma splitting in thermal boundary layers, formed at the margins of ascent <span class="hlt">conduits</span>, may operate for several km distances during magma transport from deep sources at the lower crust or upper mantle. Accordingly, <span class="hlt">conduits</span> may work as chromatographic columns contributing to increase the silica content of ascending magmas and, at the same time, leave behind residual mushes that</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhDT.......127A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhDT.......127A"><span>Characterization of molecule and particle transport through nanoscale <span class="hlt">conduits</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alibakhshi, Mohammad Amin</p> <p></p> <p>Nanofluidic devices have been of great interest due to their applications in variety of fields, including energy conversion and storage, water desalination, biological and chemical separations, and lab-on-a-chip devices. Although these applications cross the boundaries of many different disciplines, they all share the demand for understanding transport in nanoscale <span class="hlt">conduits</span>. In this thesis, different elusive aspects of molecule and particle transport through nanofluidic <span class="hlt">conduits</span> are investigated, including liquid and ion transport in nanochannels, diffusion- and reaction-governed enzyme transport in nanofluidic channels, and finally translocation of nanobeads through nanopores. Liquid or solvent transport through nanoconfinements is an essential yet barely characterized component of any nanofluidic systems. In the first chapter, water transport through single hydrophilic nanochannels with heights down to 7 nm is experimentally investigated using a new measurement technique. This technique has been developed based on the capillary flow and a novel hybrid nanochannel design and is capable of characterizing flow in both single nanoconduits as well as nanoporous media. The presence of a 0.7 nm thick hydration layer on hydrophilic surfaces and its effect on increasing the hydraulic resistance of the nanochannels is verified. Next, ion transport in a new class of nanofluidic rectifiers is theoretically and experimentally investigated. These so called nanofluidic diodes are nanochannels with asymmetric geometries which preferentially allow ion transport in one direction. A nondimensional number as a function of electrolyte concentration, nanochannel dimensions, and surface charge is derived that summarizes the rectification behavior of this system. In the fourth chapter, diffusion- and reaction-governed enzyme transport in nanofluidic channels is studied and the theoretical background necessary for understanding enzymatic activity in nanofluidic channels is presented. A</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12794092','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12794092"><span>Exercise training improves <span class="hlt">conduit</span> vessel function in patients with coronary artery disease.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Walsh, Jennifer H; Bilsborough, William; Maiorana, Andrew; Best, Matthew; O'Driscoll, Gerard J; Taylor, Roger R; Green, Daniel J</p> <p>2003-07-01</p> <p>It is well established that endothelial dysfunction is present in coronary artery disease (CAD), although few studies have determined the effect of training on peripheral <span class="hlt">conduit</span> vessel function in patients with CAD. A randomized, crossover design determined the effect of 8 wk of predominantly lower limb, combined aerobic and resistance training, in 10 patients with treated CAD. Endothelium-dependent dilation of the brachial artery was determined, by using high-resolution vascular ultrasonography, from flow-mediated vasodilation (FMD) after ischemia. Endothelium-independent vasodilation was measured after administration of glyceryl trinitrate (GTN). Baseline function was compared with that of 10 <span class="hlt">control</span> subjects. Compared with matched healthy <span class="hlt">control</span> subjects, FMD and GTN responses were significantly impaired in the untrained CAD patients [3.0 +/- 0.8 (SE) vs. 5.8 +/- 0.8% and 14.5 +/- 1.9 vs. 20.4 +/- 1.5%, respectively; both P < 0.05]. Training significantly improved FMD in the CAD patients (from 3.0 +/- 0.8 to 5.7 +/- 1.1%; P < 0.05) but not responsiveness to GTN (14.5 +/- 1.9 vs. 12.1 +/- 1.4%; P = not significant). Exercise training improves endothelium-dependent <span class="hlt">conduit</span> vessel dilation in subjects with CAD, and the effect, evident in the brachial artery, appears to be generalized rather than limited to vessels of exercising muscle beds. These results provide evidence for the benefit of exercise training, as an adjunct to routine therapy, in patients with a history of CAD.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26026910','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26026910"><span>In vivo studies of silk based gold nano-composite <span class="hlt">conduits</span> for functional peripheral nerve regeneration.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Das, Suradip; Sharma, Manav; Saharia, Dhiren; Sarma, Kushal Konwar; Sarma, Monalisa Goswami; Borthakur, Bibhuti Bhusan; Bora, Utpal</p> <p>2015-09-01</p> <p>We report a novel silk-gold nanocomposite based nerve <span class="hlt">conduit</span> successfully tested in a neurotmesis grade sciatic nerve injury model in rats over a period of eighteen months. The <span class="hlt">conduit</span> was fabricated by adsorbing gold nanoparticles onto silk fibres and transforming them into a nanocomposite sheet by electrospinning which is finally given a tubular structure by rolling on a stainless steel mandrel of chosen diameter. The <span class="hlt">conduits</span> were found to promote adhesion and proliferation of Schwann cells in vitro and did not elicit any toxic or immunogenic responses in vivo. We also report for the first time, the monitoring of muscular regeneration post nerve <span class="hlt">conduit</span> implantation by recording motor unit potentials (MUPs) through needle electromyogram. Pre-seeding the <span class="hlt">conduits</span> with Schwann cells enhanced myelination of the regenerated tissue. Histo-morphometric and electrophysiological studies proved that the nanocomposite based <span class="hlt">conduits</span> pre-seeded with Schwann cells performed best in terms of structural and functional regeneration of severed sciatic nerves. The near normal values of nerve conduction velocity (50 m/sec), compound muscle action potential (29.7 mV) and motor unit potential (133 μV) exhibited by the animals implanted with Schwann cell loaded nerve <span class="hlt">conduits</span> in the present study are superior to those observed in previous reports with synthetic materials as well as collagen based nerve <span class="hlt">conduits</span>. Animals in this group were also able to perform complex locomotory activities like stretching and jumping with excellent sciatic function index (SFI) and led a normal life.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.3558W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.3558W"><span>Sedimentary roles on hyporheic exchange in karst <span class="hlt">conduits</span> at low Reynolds numbers by laboratory experiments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Yuexia; Hunkeler, Daniel</p> <p>2017-04-01</p> <p>The relative roles of the sediment grain size/permeability, <span class="hlt">conduit</span> flow rate and <span class="hlt">conduit</span> geometry/angle on the hyporheic exchange between a karst <span class="hlt">conduit</span> and its underlying sediments under low Reynolds numbers (Re) were investigated by means of laboratory experiments and numerical simulations. Two laboratory analogues consisting of siphon structured glass tubes (with bend angles of 15° and 45°) were used for the experimental studies. Tracer experiments were performed in each analogue with sediments of variable grain size (0.45 mm, 0.4-0.7 mm, 1 mm) to characterize the transport properties of contaminants originating from the sediments. Numerical simulations were used to probe the exchange flow patterns and exchange flux magnitudes between the <span class="hlt">conduit</span> and sediment. Tracer experiments demonstrated a zone of forward flow and a zone of reverse flow in the sediments that were independent of grain size, which were reproduced well by numerical simulations. The exchange flux ranged from 0.02 % for fine grains to 2 % for coarse grains under the experimental flow conditions. A linear relationship between the exchange flux and the <span class="hlt">conduit</span> Re value, which was independent of the <span class="hlt">conduit</span> geometry and sediment grain size, was established with numerical simulations. This study demonstrated that sediment grain size/permeability has no influence on the exchange flow patterns. However, relative to the <span class="hlt">conduit</span> flow rate and <span class="hlt">conduit</span> geometry/angle, sediment permeability has a much stronger influence on the exchange rate of hyporheic flow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017HydJ...25..787W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017HydJ...25..787W"><span>Sedimentary roles on hyporheic exchange in karst <span class="hlt">conduits</span> at low Reynolds numbers by laboratory experiments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Yuexia; Hunkeler, Daniel</p> <p>2017-05-01</p> <p>The relative roles of the sediment grain size/permeability, <span class="hlt">conduit</span> flow rate and <span class="hlt">conduit</span> geometry/angle on the hyporheic exchange between a karst <span class="hlt">conduit</span> and its underlying sediments under low Reynolds numbers (Re) were investigated by means of laboratory experiments and numerical simulations. Two laboratory analogues consisting of siphon structured glass tubes (with bend angles of 15 and 45°) were used for the experimental studies. Tracer experiments were performed in each analogue with sediments of variable grain size (0.45 mm, 0.4-0.7 mm, 1 mm) to characterize the transport properties of contaminants originating from the sediments. Numerical simulations were used to probe the exchange flow patterns and exchange flux magnitudes between the <span class="hlt">conduit</span> and sediment. Tracer experiments demonstrated a zone of forward flow and a zone of reverse flow in the sediments that were independent of grain size, which were reproduced well by numerical simulations. The exchange flux ranged from 0.02% for fine grains to 2% for coarse grains under the experimental flow conditions. A linear relationship between the exchange flux and the <span class="hlt">conduit</span> Re value, which was independent of the <span class="hlt">conduit</span> geometry and sediment grain size, was established with numerical simulations. This study demonstrated that sediment grain size/permeability has no influence on the exchange flow patterns; however, relative to the <span class="hlt">conduit</span> flow rate and <span class="hlt">conduit</span> geometry/angle, sediment permeability has a much stronger influence on the exchange rate of hyporheic flow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2013-11-19/pdf/2013-27608.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2013-11-19/pdf/2013-27608.pdf"><span>78 FR 69403 - South Tahoe Public Utility District; Notice of Preliminary Determination of a Qualifying <span class="hlt">Conduit</span>...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2013-11-19</p> <p>... a Qualifying <span class="hlt">Conduit</span> Hydropower Facility and Soliciting Comments and Motions To Intervene On... qualifying <span class="hlt">conduit</span> hydropower facility, pursuant to section 30 of the Federal Power Act, as amended by section 4 of the Hydropower Regulatory Efficiency Act of 2013 (HREA). The CHYDRO Project would be...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2013-11-21/pdf/2013-27958.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2013-11-21/pdf/2013-27958.pdf"><span>78 FR 69847 - North Side Canal Company; Notice of Preliminary Determination of a Qualifying <span class="hlt">Conduit</span> Hydropower...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2013-11-21</p> <p>... Qualifying <span class="hlt">Conduit</span> Hydropower Facility and Soliciting Comments and Motions To Intervene On November 5, 2013, North Side Canal Company, filed a notice of intent to construct a qualifying <span class="hlt">conduit</span> hydropower facility, pursuant to section 30 of the Federal Power Act, as amended by section 4 of the Hydropower...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2013-10-09/pdf/2013-24407.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2013-10-09/pdf/2013-24407.pdf"><span>78 FR 61987 - Corbett Water District; Notice of Preliminary Determination of a Qualifying <span class="hlt">Conduit</span> Hydropower...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2013-10-09</p> <p>... <span class="hlt">Conduit</span> Hydropower Facility and Soliciting Comments and Motions To Intervene On September 23, 2013, Corbett Water District filed a notice of intent to construct a qualifying <span class="hlt">conduit</span> hydropower facility, pursuant to section 30 of the Federal Power Act, as amended by section 4 of the Hydropower...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2013-10-09/pdf/2013-24408.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2013-10-09/pdf/2013-24408.pdf"><span>78 FR 61985 - City of Astoria, Oregon; Notice of Preliminary Determination of a Qualifying <span class="hlt">Conduit</span> Hydropower...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2013-10-09</p> <p>... <span class="hlt">Conduit</span> Hydropower Facility and Soliciting Comments and Motions To Intervene On September 24, 2013, City of Astoria, Oregon (Astoria) filed a notice of intent to construct a qualifying <span class="hlt">conduit</span> hydropower facility, pursuant to section 30 of the Federal Power Act, as amended by section 4 of the...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2013-10-09/pdf/2013-24409.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2013-10-09/pdf/2013-24409.pdf"><span>78 FR 61986 - City of Santa Barbara, California; Notice of Preliminary Determination of a Qualifying <span class="hlt">Conduit</span>...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2013-10-09</p> <p>... Qualifying <span class="hlt">Conduit</span> Hydropower Facility and Soliciting Comments and Motions To Intervene On September 24, 2013... hydropower facility, pursuant to section 30 of the Federal Power Act, as amended by section 4 of the Hydropower Regulatory Efficiency Act of 2013 (HREA). The Gibraltar <span class="hlt">Conduit</span> Hydroelectric Project would...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017HydJ..tmp...12W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017HydJ..tmp...12W"><span>Sedimentary roles on hyporheic exchange in karst <span class="hlt">conduits</span> at low Reynolds numbers by laboratory experiments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Yuexia; Hunkeler, Daniel</p> <p>2017-01-01</p> <p>The relative roles of the sediment grain size/permeability, <span class="hlt">conduit</span> flow rate and <span class="hlt">conduit</span> geometry/angle on the hyporheic exchange between a karst <span class="hlt">conduit</span> and its underlying sediments under low Reynolds numbers (Re) were investigated by means of laboratory experiments and numerical simulations. Two laboratory analogues consisting of siphon structured glass tubes (with bend angles of 15 and 45°) were used for the experimental studies. Tracer experiments were performed in each analogue with sediments of variable grain size (0.45 mm, 0.4-0.7 mm, 1 mm) to characterize the transport properties of contaminants originating from the sediments. Numerical simulations were used to probe the exchange flow patterns and exchange flux magnitudes between the <span class="hlt">conduit</span> and sediment. Tracer experiments demonstrated a zone of forward flow and a zone of reverse flow in the sediments that were independent of grain size, which were reproduced well by numerical simulations. The exchange flux ranged from 0.02% for fine grains to 2% for coarse grains under the experimental flow conditions. A linear relationship between the exchange flux and the <span class="hlt">conduit</span> Re value, which was independent of the <span class="hlt">conduit</span> geometry and sediment grain size, was established with numerical simulations. This study demonstrated that sediment grain size/permeability has no influence on the exchange flow patterns; however, relative to the <span class="hlt">conduit</span> flow rate and <span class="hlt">conduit</span> geometry/angle, sediment permeability has a much stronger influence on the exchange rate of hyporheic flow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title30-vol1/pdf/CFR-2014-title30-vol1-sec75-700.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title30-vol1/pdf/CFR-2014-title30-vol1-sec75-700.pdf"><span>30 CFR 75.700 - Grounding metallic sheaths, armors, and <span class="hlt">conduits</span> enclosing power conductors.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Grounding metallic sheaths, armors, and... Grounding § 75.700 Grounding metallic sheaths, armors, and <span class="hlt">conduits</span> enclosing power conductors. All metallic sheaths, armors, and <span class="hlt">conduits</span> enclosing power conductors shall be electrically continuous throughout and...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title30-vol1/pdf/CFR-2011-title30-vol1-sec77-700.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title30-vol1/pdf/CFR-2011-title30-vol1-sec77-700.pdf"><span>30 CFR 77.700 - Grounding metallic sheaths, armors, and <span class="hlt">conduits</span> enclosing power conductors.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Grounding metallic sheaths, armors, and... AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Grounding § 77.700 Grounding metallic sheaths, armors, and <span class="hlt">conduits</span> enclosing power conductors. Metallic sheaths, armors, and <span class="hlt">conduits</span> enclosing power...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title30-vol1/pdf/CFR-2014-title30-vol1-sec77-700.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title30-vol1/pdf/CFR-2014-title30-vol1-sec77-700.pdf"><span>30 CFR 77.700 - Grounding metallic sheaths, armors, and <span class="hlt">conduits</span> enclosing power conductors.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Grounding metallic sheaths, armors, and... AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Grounding § 77.700 Grounding metallic sheaths, armors, and <span class="hlt">conduits</span> enclosing power conductors. Metallic sheaths, armors, and <span class="hlt">conduits</span> enclosing power...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title30-vol1/pdf/CFR-2011-title30-vol1-sec75-700.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title30-vol1/pdf/CFR-2011-title30-vol1-sec75-700.pdf"><span>30 CFR 75.700 - Grounding metallic sheaths, armors, and <span class="hlt">conduits</span> enclosing power conductors.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Grounding metallic sheaths, armors, and... Grounding § 75.700 Grounding metallic sheaths, armors, and <span class="hlt">conduits</span> enclosing power conductors. All metallic sheaths, armors, and <span class="hlt">conduits</span> enclosing power conductors shall be electrically continuous throughout and...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title30-vol1/pdf/CFR-2012-title30-vol1-sec75-700.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title30-vol1/pdf/CFR-2012-title30-vol1-sec75-700.pdf"><span>30 CFR 75.700 - Grounding metallic sheaths, armors, and <span class="hlt">conduits</span> enclosing power conductors.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Grounding metallic sheaths, armors, and... Grounding § 75.700 Grounding metallic sheaths, armors, and <span class="hlt">conduits</span> enclosing power conductors. All metallic sheaths, armors, and <span class="hlt">conduits</span> enclosing power conductors shall be electrically continuous throughout and...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title30-vol1/pdf/CFR-2012-title30-vol1-sec77-700.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title30-vol1/pdf/CFR-2012-title30-vol1-sec77-700.pdf"><span>30 CFR 77.700 - Grounding metallic sheaths, armors, and <span class="hlt">conduits</span> enclosing power conductors.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Grounding metallic sheaths, armors, and... AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Grounding § 77.700 Grounding metallic sheaths, armors, and <span class="hlt">conduits</span> enclosing power conductors. Metallic sheaths, armors, and <span class="hlt">conduits</span> enclosing power...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title30-vol1/pdf/CFR-2013-title30-vol1-sec75-700.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title30-vol1/pdf/CFR-2013-title30-vol1-sec75-700.pdf"><span>30 CFR 75.700 - Grounding metallic sheaths, armors, and <span class="hlt">conduits</span> enclosing power conductors.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Grounding metallic sheaths, armors, and... Grounding § 75.700 Grounding metallic sheaths, armors, and <span class="hlt">conduits</span> enclosing power conductors. All metallic sheaths, armors, and <span class="hlt">conduits</span> enclosing power conductors shall be electrically continuous throughout and...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title30-vol1/pdf/CFR-2013-title30-vol1-sec77-700.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title30-vol1/pdf/CFR-2013-title30-vol1-sec77-700.pdf"><span>30 CFR 77.700 - Grounding metallic sheaths, armors, and <span class="hlt">conduits</span> enclosing power conductors.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Grounding metallic sheaths, armors, and... AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Grounding § 77.700 Grounding metallic sheaths, armors, and <span class="hlt">conduits</span> enclosing power conductors. Metallic sheaths, armors, and <span class="hlt">conduits</span> enclosing power...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70035820','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70035820"><span>A one-dimensional heat-transport model for <span class="hlt">conduit</span> flow in karst aquifers</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Long, A.J.; Gilcrease, P.C.</p> <p>2009-01-01</p> <p>A one-dimensional heat-transport model for <span class="hlt">conduit</span> flow in karst aquifers is presented as an alternative to two or three-dimensional distributed-parameter models, which are data intensive and require knowledge of <span class="hlt">conduit</span> locations. This model can be applied for cases where water temperature in a well or spring receives all or part of its water from a phreatic <span class="hlt">conduit</span>. Heat transport in the <span class="hlt">conduit</span> is simulated by using a physically-based heat-transport equation that accounts for inflow of diffuse flow from smaller openings and fissures in the surrounding aquifer during periods of low recharge. Additional diffuse flow that is within the zone of influence of the well or spring but has not interacted with the <span class="hlt">conduit</span> is accounted for with a binary mixing equation to proportion these different water sources. The estimation of this proportion through inverse modeling is useful for the assessment of contaminant vulnerability and well-head or spring protection. The model was applied to 7 months of continuous temperature data for a sinking stream that recharges a <span class="hlt">conduit</span> and a pumped well open to the Madison aquifer in western South Dakota. The simulated <span class="hlt">conduit</span>-flow fraction to the well ranged from 2% to 31% of total flow, and simulated <span class="hlt">conduit</span> velocity ranged from 44 to 353 m/d.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/287630','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/287630"><span>Optimization and stability of a cable-in-<span class="hlt">conduit</span> superconductor</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Schauer, F.</p> <p>1996-07-01</p> <p>The optimization process for strand number and diameter, cable void fraction, and Cu/NbTi-ratio of the cable-in-<span class="hlt">conduit</span> conductor for the superconducting magnet system of the planned stellarator fusion experiment Wendelstein 7-X is presented. Main optimization criteria are stability and cable cooling requirements, taking into account transient disturbances and losses. A simple stability criterion regarding transient disturbances is used which is derived from cable compression experiments. The resulting data for the 16 kA, 6 T cable are: cable and strand diameter {approx}11.5 mm and {approx}0.57 mm, respectively, strand number {approx}250, void {approx}36%, and Cu/sc-ratio {approx}2.7.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GeoRL..41.8037S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GeoRL..41.8037S"><span>Hot upwelling <span class="hlt">conduit</span> beneath the Atlas Mountains, Morocco</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sun, Daoyuan; Miller, Meghan S.; Holt, Adam F.; Becker, Thorsten W.</p> <p>2014-11-01</p> <p>The Atlas Mountains of Morocco display high topography, no deep crustal root, and regions of localized Cenozoic alkaline volcanism. Previous seismic imaging and geophysical studies have implied a hot mantle upwelling as the source of the volcanism and high elevation. However, the existence, shape, and physical properties of an associated mantle anomaly are debated. Here we use seismic waveform analysis from a broadband deployment and geodynamic modeling to define the physical properties and morphology of the anomaly. The imaged low-velocity structure extends to ~200 km beneath the Atlas and appears ~350 K hotter than the ambient mantle with possible partial melting. It includes a lateral <span class="hlt">conduit</span>, which suggests that the Quaternary volcanism arises from the upper mantle. Moreover, the shape and temperature of the imaged anomaly indicate that the unusually high topography of the Atlas Mountains is due to active mantle support.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/15014560','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/15014560"><span>Effect of the <span class="hlt">conduit</span> material on CICC performance under high cycling loads</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Martovetsky, N N; Bruzzone, P; Stepanov, B; Wesche, R; Gung, C; Minervini, J V; Takayasu, M; Goodrich, L F; Ekin, J W; Nijhuis, A</p> <p>2004-09-01</p> <p>Recent ITER Model Coils and CRPP tests on Nb3Sn Cable in <span class="hlt">Conduit</span> Conductors (CICC) showed a significant and unexpected increase in the broadness of the transition to the normal state, resulting in degradation of superconducting properties. To investigate these phenomena two CICC samples were built with identical 144 strand cables but different <span class="hlt">conduit</span> materials. One sample had titanium <span class="hlt">conduit</span> with low coefficient of thermal expansion (CTE), the other had stainless steel <span class="hlt">conduit</span>. The purpose of this experiment was to study changes in strand properties in the cable (n-value, I{sub c}, T{sub cs}), the effect of cycling and high electromagnetic load and the effect of the <span class="hlt">conduit</span> on the CICC performance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1816639S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1816639S"><span>Distributed measurement of flow rate in <span class="hlt">conduits</span> using heated fiber optic distributed temperature sensing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sánchez, Raúl; Zubelzu, Sergio; Rodríguez-Sinobas, Leonor; Juana, Luis</p> <p>2016-04-01</p> <p>In some cases flow varies along <span class="hlt">conduits</span>, such as in irrigated land drainage pipes and channels, irrigation laterals and others. Detailed knowledge of flow rate along the <span class="hlt">conduit</span> makes possible analytical evaluation of water distribution and collection systems performance. Flow rate can change continuously in some systems, like in drainage pipes and channels, or abruptly, like in <span class="hlt">conduits</span> bifurcations or emitter insertions. A heat pulse along the <span class="hlt">conduit</span> makes possible to get flow rate from continuity and heat balance equations. Due to the great value of specific heat of water, temperature changes along <span class="hlt">conduit</span> are smaller than the noise that involves the measurement process. This work presents a methodology that, dealing with the noise of distributed temperature measurements, leads to flow rate determination along pressurized pipes or open channel flows.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998Cryo...38...33R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998Cryo...38...33R"><span>Large-scale tests of insulated <span class="hlt">conduit</span> for the ITER CS coil</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reed, R. P.; Walsh, R. P.; Schutz, J. B.</p> <p></p> <p>Compression-fatigue tests at 77 K were conducted on test modules of insulated Incoloy 908 <span class="hlt">conduit</span>. To replicate the operating conditions for the ITER central solenoid (CS) full-scale coil, fatigue loads up to 3.6 MN were applied for 10 5 cycles; no mechanical breakdowns occurred. The <span class="hlt">conduits</span> were insulated with a preimpregnated resin system, a tetraglycidyl diaminodiphenyl methane (TGDM) epoxy cured with DDS aromatic amine. The <span class="hlt">conduits</span> were joined by vacuum-pressure impregnation with a diglycidyl ether of bisphenol-F epoxy/anhydride-cured resin system. In the 4×4 stacked-<span class="hlt">conduit</span> test modules, the layer insulation (a high-pressure laminate of TGDM epoxy cured with DDS aromatic amine) was inserted. Periodically during the tests, breakdown voltage was measured across the <span class="hlt">conduits</span> of both turn and layer insulation; throughout the test, breakdown voltages were at least 46 kV. The addition of a barrier increased structural and electrical reliability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28761992','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28761992"><span>Novel technique for airless connection of artificial heart to vascular <span class="hlt">conduits</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Karimov, Jamshid H; Gao, Shengqiang; Dessoffy, Raymond; Sunagawa, Gengo; Sinkewich, Martin; Grady, Patrick; Sale, Shiva; Moazami, Nader; Fukamachi, Kiyotaka</p> <p>2017-07-31</p> <p>Successful implantation of a total artificial heart relies on multiple standardized procedures, primarily the resection of the native heart, and exacting preparation of the atrial and vascular <span class="hlt">conduits</span> for pump implant and activation. Achieving secure pump connections to inflow/outflow <span class="hlt">conduits</span> is critical to a successful outcome. During the connection process, however, air may be introduced into the circulation, traveling to the brain and multiple organs. Such air emboli block blood flow to these areas and are detrimental to long-term survival. A correctly managed pump-to-<span class="hlt">conduit</span> connection prevents air from collecting in the pump and <span class="hlt">conduits</span>. To further optimize pump-connection techniques, we have developed a novel connecting sleeve that enables airless connection of the Cleveland Clinic continuous-flow total artificial heart (CFTAH) to the <span class="hlt">conduits</span>. In this brief report, we describe the connecting sleeve design and our initial results from two acute in vivo implantations using a scaled-down version of the CFTAH.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JNEng..11d6024H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JNEng..11d6024H"><span>Peripheral nerve reconstruction with epsilon-caprolactone <span class="hlt">conduits</span> seeded with vasoactive intestinal peptide gene-transfected mesenchymal stem cells in a rat model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hernández-Cortés, P.; Toledo-Romero, M. A.; Delgado, M.; Sánchez-González, C. E.; Martin, F.; Galindo-Moreno, P.; O'Valle, F.</p> <p>2014-08-01</p> <p>Objective. Attempts have been made to improve nerve <span class="hlt">conduits</span> in peripheral nerve reconstruction. We investigated the potential therapeutic effect of a vasoactive intestinal peptide (VIP), a neuropeptide with neuroprotective, trophic and developmental regulatory actions, in peripheral nerve regeneration in a severe model of nerve injury that was repaired with nerve <span class="hlt">conduits</span>. Approach. The sciatic nerve of each male Wistar rat was transected unilaterally at 10 mm and then repaired with Dl-lactic-ɛ-caprolactone <span class="hlt">conduits</span>. The rats were treated locally with saline, with the VIP, with adipose-derived mesenchymal stem cells (ASCs) or with ASCs that were transduced with the VIP-expressing lentivirus. The rats with the transected nerve, with no repairs, were used as untreated <span class="hlt">controls</span>. At 12 weeks post-surgery, we assessed their limb function by measuring the ankle stance angle and the percentage of their muscle mass reduction, and we evaluated the histopathology, immunohistochemistry and morphometry of the myelinated fibers. Main results. The rats that received a single injection of VIP-expressing ASCs showed a significant functional recovery in the ankle stance angle (p = 0.049) and a higher number of myelinated fibers in the middle and distal segments of the operated nerve versus the other groups (p = 0.046). Significance. These results suggest that utilization of a cellular substrate, plus a VIP source, is a promising method for enhancing nerve regeneration using Dl-lactic-ɛ-caprolactone <span class="hlt">conduits</span> and that this method represents a potential useful clinical approach to repairing peripheral nerve damage.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70136548','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70136548"><span>Dynamics within geyser <span class="hlt">conduits</span>, and sensitivity to environmental perturbations: insights from a periodic geyser in the El Tatio Geyser Field, Atacama Desert, Chile</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Munoz-Saez, Carolina; Manga, Michael; Hurwitz, Shaul; Rudolph, Maxwell L.; Namiki, Atsuko; Wang, Chi-Yuen</p> <p>2015-01-01</p> <p>Despite more than 200 years of scientific study, the internal dynamics of geyser systems remain poorly characterized. As a consequence, there remain fundamental questions about what processes initiate and terminate eruptions, and where eruptions begin. Over a one-week period in October 2012, we collected down-hole measurements of pressure and temperature in the <span class="hlt">conduit</span> of an exceptionally regular geyser (132 s/cycle) located in the Chilean desert. We identified four stages in the geyser cycle: (1) recharge of water into the <span class="hlt">conduit</span> after an eruption, driven by the pressure difference between water in the <span class="hlt">conduit</span> and in a deeper reservoir; (2) a pre-eruptive stage that follows the recharge and is dominated by addition of steam from below; (3) the eruption, which occurs by rapid boiling of a large mass of water at the top of the water column, and decompression that propagates boiling conditions downward; (4) a relaxation stage during which pressure and temperature decrease until conditions preceding the recharge stage are restored. Eruptions are triggered by the episodic addition of steam coming from depth, suggesting that the dynamics of the eruptions are dominated by geometrical and thermodynamic complexities in the <span class="hlt">conduit</span> and reservoir. Further evidence favoring the dominance of internal processes in <span class="hlt">controlling</span> periodicity is also provided by the absence of responses of the geyser to environmental perturbations (air pressure, temperature and probably also Earth tides).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA.....9504M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA.....9504M"><span>Laboratory experiments on <span class="hlt">conduit</span> kinetics of 2001 and 2002 Mount Etna eruptions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mincione, V.; Trigila, R.</p> <p>2003-04-01</p> <p>During the 2001and 2002 Mt. Etna eruptions lavas and ashes with peculiar mineralogical and textural characters, i.e. low porfiricity index, scarcity of plagioclase phenocrysts, appearance of amphibole among mineral phases, have been erupted. Moreover, the eruptions of these peculiar products took place with an anomalously high explovity index for Etna volcano. In order to constrain <span class="hlt">conduit</span> parameters responsible for these volcanological features, two sets of experiments have been run, using a rapid quenching TZM externally heated pressure vessel. One set of experiments was performed at eruptive temperature and constant pressure (T = 950°-1050°; P = 200 MPa) to investigate the rock paragenesis, the order of crystallization and the amount of dissolved gases pertinent to magmatic chamber conditions. The experiments were run at <span class="hlt">controlled</span> NNO oxygen fugacity and samples were satured initially with water or oxalic acid diidrated. Samples were collected from different vents and showed different porfiricity and paragenesis. All the samples run at such conditions show the same crystalline assemblage: plagioclase, diopsidic clinopyroxene, olivine, titanomagnetite and amphibole. These results may indicate that the differences in the porfiricity and paragenesis observed in natural products are not related to a different source of the magmatic masses but simply to a different kinetics of the magma ascent. Therefore, the second set of experiments was performed on purpose at the same temperatures and different decompression rate (from 200MPa to 20MPa in 1 hour, 12 hour and 24h), in order to investigate the role of ascent velocity in the volcanic <span class="hlt">conduit</span>. The samples were decompressed acting manually on the TZM purge valve, connected on purpose with a fluximeter. Preliminary results show a straight influence of decompression kinetics on some features of the experimental products, as the porfiric index, the occurence of amphibole among mineral species and the amount of gases</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.V21C2006P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.V21C2006P"><span>Open system degassing, bubble rise and flow dynamics within volcanic <span class="hlt">conduits</span>- an experimental approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pioli, L.; Azzopardi, B. J.; Bonadonna, C.; Marchetti, E.; Ripepe, M.</p> <p>2009-12-01</p> <p>Open <span class="hlt">conduit</span> basaltic volcanoes are characterized by frequent eruptions, usually consisting in mild Strombolian and Hawaiian explosions, alternating years to months of quiescence periods, with degassing activity from the central <span class="hlt">conduit</span>. Recent improvements of thermal, video, radar and acoustic monitoring techniques have provided new powerful tools for the study of degassing processes and made available geophysical and geochemical datasets for many central volcanoes, such as Stromboli, Etna (Italy), Kilauea (Hawaii), Villarrica (Chile). These studies revealed that degassing is an unsteady, often pulsatory process, characterized by fluctuations in both intensity and composition of the emitted gases. Unambiguous interpretation of monitoring data of surface activity in terms of <span class="hlt">conduit</span> dynamics and flow processes is, however, not possible, due to partial knowledge of the physical processes <span class="hlt">controlling</span> the dynamics of two-phase flows in magmas. We performed a series of experiments to gain further insights on the dynamics of the gas-bubble rise in magmas within a cylindrical <span class="hlt">conduit</span>, their ability to segregate and coalesce and the effect of these processes on the degassing dynamics. The experiments consisted in generating fluxes at variable intensities of air through stagnant water or glucose syrup in a bubble column apparatus 6.5 m high and with a diameter of 24 cm diameter. Glucose syrup and water are Newtonian liquids with viscosity ranging from 2.4 to 204.0 Pa*s and from 1.7 to 0.2 10 -3 Pa*s respectively, depending on temperature. Air was inserted at the base of the column through a variable number (1 to 25) of 5mm-diameter nozzles reaching surficial gas velocities of up to 0.5 m/s. The activity of the bubble column was monitored through temperature, pressure, void fraction and acoustic measurements and filmed by a high-speed camera with maximum resolution of 800x600 pixels. Pressure fluctuations, vesicularity and acoustic signal were then analyzed and correlated</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4145904','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4145904"><span>Poly(lactic-co-glycolic acid) <span class="hlt">conduit</span> for repair of injured sciatic nerve: A mechanical analysis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yu, Tao; Zhao, Changfu; Li, Peng; Liu, Guangyao; Luo, Min</p> <p>2013-01-01</p> <p>Tensile stress and tensile strain directly affect the quality of nerve regeneration after bridging nerve defects by poly(lactic-co-glycolic acid) <span class="hlt">conduit</span> transplantation and autogenous nerve grafting for sciatic nerve injury. This study collected the sciatic nerve from the gluteus maximus muscle from fresh human cadaver, and established 10-mm-long sciatic nerve injury models by removing the ischium, following which poly(lactic-co-glycolic acid) <span class="hlt">conduits</span> or autogenous nerve grafts were transplanted. Scanning electron microscopy revealed that the axon and myelin sheath were torn, and the vessels of basilar membrane were obstructed in the poly(lactic-co-glycolic acid) <span class="hlt">conduit</span>-repaired sciatic nerve following tensile testing. There were no significant differences in tensile tests with autogenous nerve graft-repaired sciatic nerve. Following poly(lactic-co-glycolic acid) <span class="hlt">conduit</span> transplantation for sciatic nerve repair, tensile test results suggest that maximum tensile load, maximum stress, elastic limit load and elastic limit stress increased compared with autogenous nerve grafts, but elastic limit strain and maximum strain decreased. Moreover, the tendencies of stress-strain curves of sciatic nerves were similar after transplantation of poly(lactic-co-glycolic acid) <span class="hlt">conduits</span> or autogenous nerve grafts. Results showed that after transplantation in vitro for sciatic nerve injury, poly(lactic-co-glycolic acid) <span class="hlt">conduits</span> exhibited good intensity, elasticity and plasticity, indicating that poly(lactic-co-glycolic acid) <span class="hlt">conduits</span> are suitable for sciatic nerve injury repair. PMID:25206505</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25206505','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25206505"><span>Poly(lactic-co-glycolic acid) <span class="hlt">conduit</span> for repair of injured sciatic nerve: A mechanical analysis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yu, Tao; Zhao, Changfu; Li, Peng; Liu, Guangyao; Luo, Min</p> <p>2013-07-25</p> <p>Tensile stress and tensile strain directly affect the quality of nerve regeneration after bridging nerve defects by poly(lactic-co-glycolic acid) <span class="hlt">conduit</span> transplantation and autogenous nerve grafting for sciatic nerve injury. This study collected the sciatic nerve from the gluteus maximus muscle from fresh human cadaver, and established 10-mm-long sciatic nerve injury models by removing the ischium, following which poly(lactic-co-glycolic acid) <span class="hlt">conduits</span> or autogenous nerve grafts were transplanted. Scanning electron microscopy revealed that the axon and myelin sheath were torn, and the vessels of basilar membrane were obstructed in the poly(lactic-co-glycolic acid) <span class="hlt">conduit</span>-repaired sciatic nerve following tensile testing. There were no significant differences in tensile tests with autogenous nerve graft-repaired sciatic nerve. Following poly(lactic-co-glycolic acid) <span class="hlt">conduit</span> transplantation for sciatic nerve repair, tensile test results suggest that maximum tensile load, maximum stress, elastic limit load and elastic limit stress increased compared with autogenous nerve grafts, but elastic limit strain and maximum strain decreased. Moreover, the tendencies of stress-strain curves of sciatic nerves were similar after transplantation of poly(lactic-co-glycolic acid) <span class="hlt">conduits</span> or autogenous nerve grafts. Results showed that after transplantation in vitro for sciatic nerve injury, poly(lactic-co-glycolic acid) <span class="hlt">conduits</span> exhibited good intensity, elasticity and plasticity, indicating that poly(lactic-co-glycolic acid) <span class="hlt">conduits</span> are suitable for sciatic nerve injury repair.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4774210','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4774210"><span>A novel bioactive nerve <span class="hlt">conduit</span> for the repair of peripheral nerve injury</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Li, Bin-bin; Yin, Yi-xia; Yan, Qiong-jiao; Wang, Xin-yu; Li, Shi-pu</p> <p>2016-01-01</p> <p>The use of a nerve <span class="hlt">conduit</span> provides an opportunity to regulate cytokines, growth factors and neurotrophins in peripheral nerve regeneration and avoid autograft defects. We constructed a poly-D-L-lactide (PDLLA)-based nerve <span class="hlt">conduit</span> that was modified using poly{(lactic acid)-co-[(glycolic acid)-alt-(L-lysine)]} and β-tricalcium phosphate. The effectiveness of this bioactive PDLLA-based nerve <span class="hlt">conduit</span> was compared to that of PDLLA-only <span class="hlt">conduit</span> in the nerve regeneration following a 10-mm sciatic nerve injury in rats. We observed the nerve morphology in the early period of regeneration, 35 days post injury, using hematoxylin-eosin and methylene blue staining. Compared with the PDLLA <span class="hlt">conduit</span>, the nerve fibers in the PDLLA-based bioactive nerve <span class="hlt">conduit</span> were thicker and more regular in size. Muscle fibers in the soleus muscle had greater diameters in the PDLLA bioactive group than in the PDLLA only group. The PDLLA-based bioactive nerve <span class="hlt">conduit</span> is a promising strategy for repair after sciatic nerve injury. PMID:26981105</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.V31A3069Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.V31A3069Y"><span>Hydrothermal Alteration of the Mt Unzen <span class="hlt">Conduit</span> (Shimabara/Japan)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yilmaz, T. I.; Mayer, K.; Hess, K. U.; Janots, E.; Gilg, H. A.; Dingwell, D. B.</p> <p>2016-12-01</p> <p>Investigations were carried out on hydrothermally altered coherent dacitic dykes samples from (USDP-4) drill core at Mt Unzen stratovolcano (Shimabara/Japan). XRF, XRD, EMPA, and C-O-isotope analysis led to insights concerning chemistry, mineralogy, and intensity of alteration as well as the origin of carbonate-precipitating fluids. Additionally a textural characterization of the occurring replacement features in the magma <span class="hlt">conduit</span> zone was performed. The occurrence of the main secondary phases such as chlorite, pyrite, carbonates, and R1 (Reichweite parameter) illite-smectite indicate a weak to moderate propylitic to phyllic hydrothermal alteration. The dacitic samples of the dykes show different hydrothermal alteration features: (i) carbonate pseudomorphs after hornblende as well as core and zonal textures due to replacement of plagioclase by R1 illite-smectite, (ii) colloform banded fracture fillings and fillings in dissolution vugs, and (iii) chlorite and R1 illite-smectite in the groundmass. Carbonates in fractures comprise iron-rich dolomite solid solutions ("ankerite") and calcite. Isotopic values of d13Cvpdb = -4.59 ± 0.6‰ and d18Ovpdb = -21.73 ± 0.5‰ indicate a hydrothermal-magmatic origin for the carbonate formation. The chlorite-carbonate-pyrite index (CCPI) and the Ishikawa alteration index (AI), applied to the investigated samples show significant differences (CCPI=52.7-57.8; AI=36.1-40.6) indicating their different degree of alteration. According to Nakada et al., 2005, the C13 to C16 dykes represent the feeder dyke from the latest eruption (1991-1995) whereas C8 represents an earlier dyke feeder dyke from an older eruption. Weakest <span class="hlt">conduit</span> alteration, which was obtained in samples C16-1-5 and C13-2-5, correlates with the alteration degree of the pristine dome rocks. Highest CCPI value was determined for sample C14-1-5 and the highest AI value was determined for sample C15-2-6. The degrees of alteration do not indicate highest alteration of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23090775','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23090775"><span>Impaired role of epoxyeicosatrienoic acids in the regulation of basal <span class="hlt">conduit</span> artery diameter during essential hypertension.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bellien, Jeremy; Remy-Jouet, Isabelle; Iacob, Michele; Blot, Etienne; Mercier, Alain; Lucas, Daniele; Dreano, Yvonne; Gutierrez, Laurence; Donnadieu, Nathalie; Thuillez, Christian; Joannides, Robinson</p> <p>2012-12-01</p> <p>In young healthy subjects, epoxyeicosatrienoic acids synthesized by endothelial cytochrome P450 epoxygenases maintain basal <span class="hlt">conduit</span> artery diameter during altered NO availability. Whether this compensatory mechanism is effective during essential hypertension is unknown. Radial artery diameter, blood flow, and mean wall shear stress were determined in 14 nontreated essential hypertensive patients and 14 normotensive <span class="hlt">control</span> subjects during 8 minutes of brachial infusion for inhibitors of cytochrome P450 epoxygenases (fluconazole, 0.4 µmol/min) and NO synthase (N(G)-monomethyl-L-arginine, 8 µmol/min) alone and in combination. In <span class="hlt">controls</span>, the radial artery diameter was reduced by fluconazole (-0.034 ± 0.012 mm) and N(G)-monomethyl-L-arginine (-0.037 ± 0.010 mm) and to a larger extent by their combination (-0.137 ± 0.011 mm), demonstrating a synergic effect. In contrast, the radial diameter in hypertensive patients was not affected by fluconazole (0.010 ± 0.014 mm) but was reduced by N(G)-monomethyl-L-arginine (-0.091 ± 0.008 mm) to a larger extent than in <span class="hlt">controls</span>. In parallel, N(G)-monomethyl-L-arginine decreased local plasma nitrite to a lesser extent in hypertensive patients (-14 ± 5 nmol/L) than in <span class="hlt">controls</span> (-50 ± 10 nmol/L). Moreover, the addition of fluconazole to N(G)-monomethyl-L-arginine did not further decrease radial diameter in patients (-0.086 ± 0.011 mm). Accordingly, fluconazole significantly decreased local epoxyeicosatrienoic acid plasma level in <span class="hlt">controls</span> (-2.0 ± 0.6 ng/mL) but not in patients (-0.9 ± 0.4 ng/mL). Inhibitors effects on blood flow and endothelium-independent dilatation to sodium nitroprusside were similar between groups. These results show that, in contrast to normotensive subjects, epoxyeicosatrienoic acids did not contribute to the regulation of basal <span class="hlt">conduit</span> artery diameter and did not compensate for altered NO availability to maintain this diameter in essential hypertensive patients.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4151583','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4151583"><span>Forgotten DJ Stent with a Large Calculus at Its Distal End in an Ileal <span class="hlt">Conduit</span> Diversion</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Puri, Anurag; Priyadarshi, Vinod; Raizada, Nivedita; Pal, Dilip Kumar</p> <p>2014-01-01</p> <p>Calculus formation in an ileal <span class="hlt">conduit</span> following cystectomy is a known complication. Encrustation and formation of calculus may also occur over a DJ stent retained for a long period; but this is never reported in patients with <span class="hlt">conduit</span> diversion because of close surveillance of these patients. Here we report first case of a large calculus encrusted over a forgotten DJ stent within an ileal <span class="hlt">conduit</span> in a man who had undergone urinary diversion following radical cystectomy for carcinoma urinary bladder 8 years earlier. PMID:25215257</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22508165','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22508165"><span><span class="hlt">Conduit</span> diameter and wall remodeling in elite athletes and spinal cord injury.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rowley, Nicola Jayne; Dawson, Ellen Adele; Hopman, Maria T E; George, Keith P; Whyte, Greg P; Thijssen, Dick H J; Green, Daniel John</p> <p>2012-05-01</p> <p>This study aimed to investigate localized and systemic effects of chronic exercise and inactivity on <span class="hlt">conduit</span> artery remodeling in humans. We recruited elite athletes engaged in predominantly lower limb (LL runners/cyclists, n = 10) or upper limb (UL canoe paddlers, n = 12) exercise and matched able-bodied, recreationally active, <span class="hlt">controls</span> (C, n = 16). We also studied wheelchair <span class="hlt">controls</span> (spinal cord injury, n = 9) and athletes (spinal cord injury, n = 1; spina bifida, n = 4). Carotid, brachial, and superficial femoral (SF) artery diameter and wall thickness were assessed using high-resolution ultrasound. Brachial diameters were significantly larger in UL and wheelchair users (athletes and <span class="hlt">controls</span>) compared with C (both P < 0.05). SF artery diameter in wheelchair <span class="hlt">controls</span> was significantly smaller compared with the other groups, with LL athletes having significantly greater lumen diameter than <span class="hlt">controls</span> (both P < 0.05). In all arteries, a lower wall thickness was found in able-bodied athletes compared with C, including wheelchair athletes compared with wheelchair <span class="hlt">controls</span> (P < 0.001). In the SF artery, wall-to-lumen-ratio was significantly lower in able-bodied athletes and higher in wheelchair <span class="hlt">controls</span> compared with able-bodied <span class="hlt">controls</span> (P < 0.001). In the brachial and carotid arteries, able-bodied and wheelchair athletes demonstrated lower wall-to-lumen-ratio than less active wheelchair <span class="hlt">controls</span> and able-bodied <span class="hlt">controls</span> (P < 0.001). These findings suggest that remodeling of the arterial wall occurs systemically in response to exercise training and is unrelated to exercise type in humans. Conversely, localized effects are evident with respect to the effect of exercise on arterial diameter. These findings have implications for our understanding of the effects of exercise on arterial structure and function in humans.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10879532','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10879532"><span>Mapping the Hawaiian plume <span class="hlt">conduit</span> with converted seismic waves</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li; Kind; Priestley; Sobolev; Tilmann; Yuan; Weber</p> <p>2000-06-22</p> <p>The volcanic edifice of the Hawaiian islands and seamounts, as well as the surrounding area of shallow sea floor known as the Hawaiian swell, are believed to result from the passage of the oceanic lithosphere over a mantle hotspot. Although geochemical and gravity observations indicate the existence of a mantle thermal plume beneath Hawaii, no direct seismic evidence for such a plume in the upper mantle has yet been found. Here we present an analysis of compressional-to-shear (P-to-S) converted seismic phases, recorded on seismograph stations on the Hawaiian islands, that indicate a zone of very low shear-wave velocity (< 4 km s(-1)) starting at 130-140 km depth beneath the central part of the island of Hawaii and extending deeper into the upper mantle. We also find that the upper-mantle transition zone (410-660 km depth) appears to be thinned by up to 40-50 km to the south-southwest of the island of Hawaii. We interpret these observations as localized effects of the Hawaiian plume <span class="hlt">conduit</span> in the asthenosphere and mantle transition zone with excess temperature of approximately 300 degrees C. Large variations in the transition-zone thickness suggest a lower-mantle origin of the Hawaiian plume similar to the Iceland plume, but our results indicate a 100 degrees C higher temperature for the Hawaiian plume.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1016439','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1016439"><span>Structure of a Bacterial Cell Surface Decaheme Electron <span class="hlt">Conduit</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Clarke, Thomas A.; Edwards, Marcus; Gates, Andrew J.; Hall, Andrea; White, Gaye; Bradley, Justin; Reardon, Catherine L.; Shi, Liang; Beliaev, Alex S.; Marshall, Matthew J.; Wang, Zheming; Watmough, Nicholas; Fredrickson, Jim K.; Zachara, John M.; Butt, Julea N.; Richardson, David J.</p> <p>2011-05-23</p> <p>Some bacterial species are able to utilize extracellular mineral forms of iron and manganese as respiratory electron acceptors. In Shewanella oneidensis this involves deca-heme cytochromes that are located on the bacterial cell surface at the termini of trans-outermembrane (OM) electron transfer <span class="hlt">conduits</span>. The cell surface cytochromes can potentially play multiple roles in mediating electron transfer directly to insoluble electron sinks, catalyzing electron exchange with flavin electron shuttles or participating in extracellular inter-cytochrome electron exchange along ‘nanowire’ appendages. We present a 3.2 Å crystal structure of one of these deca-heme cytochromes, MtrF, that allows the spatial organization of the ten hemes to be visualized for the first time. The hemes are organized across four domains in a unique crossed conformation, in which a staggered 65 Å octa-heme chain transects the length of the protein and is bisected by a planar 45 Å tetra-heme chain that connects two extended Greek key split β-barrel domains. The structure provides molecular insight into how reduction of insoluble substrate (e.g. minerals), soluble substrates (e.g. flavins) and cytochrome redox partners might be possible in tandem at different termini of a trifurcated electron transport chain on the cell surface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3111324','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3111324"><span>Structure of a bacterial cell surface decaheme electron <span class="hlt">conduit</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Clarke, Thomas A.; Edwards, Marcus J.; Gates, Andrew J.; Hall, Andrea; White, Gaye F.; Bradley, Justin; Reardon, Catherine L.; Shi, Liang; Beliaev, Alexander S.; Marshall, Matthew J.; Wang, Zheming; Watmough, Nicholas J.; Fredrickson, James K.; Zachara, John M.; Butt, Julea N.; Richardson, David J.</p> <p>2011-01-01</p> <p>Some bacterial species are able to utilize extracellular mineral forms of iron and manganese as respiratory electron acceptors. In Shewanella oneidensis this involves decaheme cytochromes that are located on the bacterial cell surface at the termini of trans-outer-membrane electron transfer <span class="hlt">conduits</span>. The cell surface cytochromes can potentially play multiple roles in mediating electron transfer directly to insoluble electron sinks, catalyzing electron exchange with flavin electron shuttles or participating in extracellular intercytochrome electron exchange along “nanowire” appendages. We present a 3.2-Å crystal structure of one of these decaheme cytochromes, MtrF, that allows the spatial organization of the 10 hemes to be visualized for the first time. The hemes are organized across four domains in a unique crossed conformation, in which a staggered 65-Å octaheme chain transects the length of the protein and is bisected by a planar 45-Å tetraheme chain that connects two extended Greek key split β-barrel domains. The structure provides molecular insight into how reduction of insoluble substrate (e.g., minerals), soluble substrates (e.g., flavins), and cytochrome redox partners might be possible in tandem at different termini of a trifurcated electron transport chain on the cell surface. PMID:21606337</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2984186','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2984186"><span>Engineering of a synthetic electron <span class="hlt">conduit</span> in living cells</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jensen, Heather M.; Albers, Aaron E.; Malley, Konstantin R.; Londer, Yuri Y.; Cohen, Bruce E.; Helms, Brett A.; Weigele, Peter; Groves, Jay T.; Ajo-Franklin, Caroline M.</p> <p>2010-01-01</p> <p>Engineering efficient, directional electronic communication between living and nonliving systems has the potential to combine the unique characteristics of both materials for advanced biotechnological applications. However, the cell membrane is designed by nature to be an insulator, restricting the flow of charged species; therefore, introducing a biocompatible pathway for transferring electrons across the membrane without disrupting the cell is a significant challenge. Here we describe a genetic strategy to move intracellular electrons to an inorganic extracellular acceptor along a molecularly defined route. To do so, we reconstitute a portion of the extracellular electron transfer chain of Shewanella oneidensis MR-1 into the model microbe Escherichia coli. This engineered E. coli can reduce metal ions and solid metal oxides ∼8× and ∼4× faster than its parental strain. We also find that metal oxide reduction is more efficient when the extracellular electron acceptor has nanoscale dimensions. This work demonstrates that a genetic cassette can create a <span class="hlt">conduit</span> for electronic communication from living cells to inorganic materials, and it highlights the importance of matching the size scale of the protein donors to inorganic acceptors. PMID:20956333</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21606337','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21606337"><span>Structure of a bacterial cell surface decaheme electron <span class="hlt">conduit</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Clarke, Thomas A; Edwards, Marcus J; Gates, Andrew J; Hall, Andrea; White, Gaye F; Bradley, Justin; Reardon, Catherine L; Shi, Liang; Beliaev, Alexander S; Marshall, Matthew J; Wang, Zheming; Watmough, Nicholas J; Fredrickson, James K; Zachara, John M; Butt, Julea N; Richardson, David J</p> <p>2011-06-07</p> <p>Some bacterial species are able to utilize extracellular mineral forms of iron and manganese as respiratory electron acceptors. In Shewanella oneidensis this involves decaheme cytochromes that are located on the bacterial cell surface at the termini of trans-outer-membrane electron transfer <span class="hlt">conduits</span>. The cell surface cytochromes can potentially play multiple roles in mediating electron transfer directly to insoluble electron sinks, catalyzing electron exchange with flavin electron shuttles or participating in extracellular intercytochrome electron exchange along "nanowire" appendages. We present a 3.2-Å crystal structure of one of these decaheme cytochromes, MtrF, that allows the spatial organization of the 10 hemes to be visualized for the first time. The hemes are organized across four domains in a unique crossed conformation, in which a staggered 65-Å octaheme chain transects the length of the protein and is bisected by a planar 45-Å tetraheme chain that connects two extended Greek key split β-barrel domains. The structure provides molecular insight into how reduction of insoluble substrate (e.g., minerals), soluble substrates (e.g., flavins), and cytochrome redox partners might be possible in tandem at different termini of a trifurcated electron transport chain on the cell surface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010LaPhL...7..246B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010LaPhL...7..246B"><span>In vivo visualization of microneedle <span class="hlt">conduits</span> in human skin using laser scanning microscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bal, S.; Kruithof, A. C.; Liebl, H.; Tomerius, M.; Bouwstra, J.; Lademann, J.; Meinke, M.</p> <p>2010-03-01</p> <p>Solid microneedles enhance the penetration of drugs into the viable skin but little is known about the geometry of the <span class="hlt">conduits</span> in vivo. Therefore, laser scanning microscopy was used to visualize the <span class="hlt">conduits</span> of a microneedle system with needles at a length of 300 μm in 6 healthy subjects over a period of time. The model drug, a fluorescent dye was applied before and after piercing. Laser scanning microscopy was evaluated as being an excellent method to monitor the geometry and closure of the <span class="hlt">conduits</span> over time. The used microneedle system was evaluated as suitable to enhance the transport of model drugs into the viable epidermis without bleeding and a short closure time of the <span class="hlt">conduits</span> at the skin surface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4281169','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4281169"><span>Effect of Multiwall Carbon Nanotube Reinforcement on Coaxially Extruded Cellular Vascular <span class="hlt">Conduits</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhang, Yahui; Yu, Yin; Dolati, Farzaneh; Ozbolat, Ibrahim T</p> <p>2014-01-01</p> <p>Due to its abundant source, good biocompatibility, low price and mild crosslinking process, alginate is an ideal selection for tissue engineering applications. In this work, alginate vascular <span class="hlt">conduits</span> were fabricated through a coaxial extrusion-based system. However, due to the inherent weak mechanical properties of alginate, the vascular <span class="hlt">conduits</span> are not capable of biomimicking natural vascular system. In this paper, multiwall carbon nanotubes (MWCNT) were used to reinforce vascular <span class="hlt">conduits</span>. Mechanical, dehydration, swelling and degradation tests were performed to understand influences of MWCNT reinforcement. The unique mechanical properties together with perfusion and diffusional capability are two important factors to mimic the nature. Thus, perfusion experiments were also conducted to explore the MWCNT reinforcement effect. In addition, cell viability and tissue histology were conducted to evaluate the biological performance of <span class="hlt">conduits</span> both in short and long term for MWCNT reinforcement. PMID:24863208</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/416678','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/416678"><span>Development of bending characteristics for the TPX TF magnet coil cable-in-<span class="hlt">conduit</span> conductor</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Grut, K.E.; Holbrook, R.L.; Hook, E.; Antaya, T.A.</p> <p>1996-12-31</p> <p>The conductor for the toroidal field (TF) magnet coils for the Tokamak Physics experiment (TPX) is an assembly of stranded Nb{sub 3}Sn superconductor sheathed by an Incoloy 908 <span class="hlt">conduit</span>. The coil shape, when coupled with stiffness of the cable-in-<span class="hlt">conduit</span> conductor (CICC) is such that conventional magnet winding techniques cannot be utilized. Therefore a bending and forming method will be employed in the TF coils. The cable will be reacted after bending because the reaction process hardens the <span class="hlt">conduit</span> and also lowers the strain the cable can withstand without performance degradation. The Incoloy 908 <span class="hlt">conduit</span> also work hardens quickly, necessitating the production of the required coil shape in one step without correction. This paper discusses the limiting processes for forming the TPX TF magnet geometry, the methods utilized in establishing the CICC bending characteristics and the methods employed to account for material springback so that a coil can be manufactured accurately and efficiently.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AdWR...90...99B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AdWR...90...99B"><span>Can one identify karst <span class="hlt">conduit</span> networks geometry and properties from hydraulic and tracer test data?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Borghi, Andrea; Renard, Philippe; Cornaton, Fabien</p> <p>2016-04-01</p> <p>Karst aquifers are characterized by extreme heterogeneity due to the presence of karst <span class="hlt">conduits</span> embedded in a fractured matrix having a much lower hydraulic conductivity. The resulting contrast in the physical properties of the system implies that the system reacts very rapidly to some changes in the boundary conditions and that numerical models are extremely sensitive to small modifications in properties or positions of the <span class="hlt">conduits</span>. Furthermore, one major issue in all those models is that the location and size of the <span class="hlt">conduits</span> is generally unknown. For all those reasons, estimating karst network geometry and their properties by solving an inverse problem is a particularly difficult problem. In this paper, two numerical experiments are described. In the first one, 18,000 flow and transport simulations have been computed and used in a systematic manner to assess statistically if one can retrieve the parameters of a model (geometry and radius of the <span class="hlt">conduits</span>, hydraulic conductivity of the <span class="hlt">conduits</span>) from head and tracer data. When two tracer test data sets are available, the solution of the inverse problems indicate with high certainty that there are indeed two <span class="hlt">conduits</span> and not more. The radius of the <span class="hlt">conduits</span> are usually well identified but not the properties of the matrix. If more <span class="hlt">conduits</span> are present in the system, but only two tracer test data sets are available, the inverse problem is still able to identify the true solution as the most probable but it also indicates that the data are insufficient to conclude with high certainty. In the second experiment, a more complex model (including non linear flow equations in <span class="hlt">conduits</span>) is considered. In this example, gradient-based optimization techniques are proved to be efficient for estimating the radius of the <span class="hlt">conduits</span> and the hydraulic conductivity of the matrix in a promising and efficient manner. These results suggest that, despite the numerical difficulties, inverse methods should be used to constrain numerical</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70036473','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70036473"><span>Effects of dynamically variable saturation and matrix-<span class="hlt">conduit</span> coupling of flow in karst aquifers</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Reimann, T.; Geyer, T.; Shoemaker, W.B.; Liedl, R.; Sauter, M.</p> <p>2011-01-01</p> <p>Well-developed karst aquifers consist of highly conductive <span class="hlt">conduits</span> and a relatively low permeability fractured and/or porous rock matrix and therefore behave as a dual-hydraulic system. Groundwater flow within highly permeable strata is rapid and transient and depends on local flow conditions, i.e., pressurized or nonpressurized flow. The characterization of karst aquifers is a necessary and challenging task because information about hydraulic and spatial <span class="hlt">conduit</span> properties is poorly defined or unknown. To investigate karst aquifers, hydraulic stresses such as large recharge events can be simulated with hybrid (coupled discrete continuum) models. Since existing hybrid models are simplifications of the system dynamics, a new karst model (ModBraC) is presented that accounts for unsteady and nonuniform discrete flow in variably saturated <span class="hlt">conduits</span> employing the Saint-Venant equations. Model performance tests indicate that ModBraC is able to simulate (1) unsteady and nonuniform flow in variably filled <span class="hlt">conduits</span>, (2) draining and refilling of <span class="hlt">conduits</span> with stable transition between free-surface and pressurized flow and correct storage representation, (3) water exchange between matrix and variably filled <span class="hlt">conduits</span>, and (4) discharge routing through branched and intermeshed <span class="hlt">conduit</span> networks. Subsequently, ModBraC is applied to an idealized catchment to investigate the significance of free-surface flow representation. A parameter study is conducted with two different initial conditions: (1) pressurized flow and (2) free-surface flow. If free-surface flow prevails, the systems is characterized by (1) a time lag for signal transmission, (2) a typical spring discharge pattern representing the transition from pressurized to free-surface flow, and (3) a reduced <span class="hlt">conduit</span>-matrix interaction during free-surface flow. Copyright 2011 by the American Geophysical Union.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.5637A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.5637A"><span>Numerical Calculation of LP Seismic Signals Modeling the Fluid-Rock Interaction in Simulated Volcanic <span class="hlt">Conduits</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arciniega-Ceballos, Alejandra; Corona-Romero, Pedro; Sanchez-Sesma, Francisco</p> <p>2010-05-01</p> <p>We present an investigation of the fluid-solid dynamic interaction of a fluid-driven cylindrical <span class="hlt">conduit</span> embedded within an infinite, homogeneous elastic space with physical properties similar to those encountered in volcanic environments. In our model, a pressure transient is applied at the bottom of the <span class="hlt">conduit</span>, which perturbs the steady flow of incompressible viscous fluid, driven by a pressure gradient. The model includes radial variation of a cylindrical fluid-filled <span class="hlt">conduit</span> driven by changes in the flow velocity of a Newtonian fluid and a pressure gradient. Both fluid and solid are dynamically coupled by the continuity of radial velocities and shear and radial stresses at the <span class="hlt">conduit</span> wall. The <span class="hlt">conduit</span> dynamics are governed by three ordinary non-linear differential equations of second order, which are solved numerically by applying a fifth-order Runge-Kutta scheme. Our model allows for any number of pipe segments of different sizes coupled in series, thus representing an extended source region, which closely mimics the geometry of realistic volcanic <span class="hlt">conduits</span>. Various examples of fluid-filled pipe-systems, starting from the simplest penny-shape geometries up to <span class="hlt">conduits</span> of hundreds of meters in length, are presented. The values assumed for the fluid density and viscosity are in the mean range of basaltic and andesitic composition. Far-field velocity synthetics radiated by the motion of the <span class="hlt">conduit</span> and fluid flows ascending to the surface display characteristic waveforms and frequency contents that closely resemble those of long-period (LP) signals observed at active volcanoes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28556988','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28556988"><span>Laparoscopic ischemic conditioning of the stomach increases neovascularization of the gastric <span class="hlt">conduit</span> in patients undergoing esophagectomy for cancer.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pham, Thai H; Melton, Shelby D; McLaren, Patrick J; Mokdad, Ali A; Huerta, Sergio; Wang, David H; Perry, Kyle A; Hardaker, Hope L; Dolan, James P</p> <p>2017-09-01</p> <p>Gastric ischemic preconditioning has been proposed to improve blood flow and reduce the incidence of anastomotic complications following esophagectomy with gastric pull-up. This study aimed to evaluate the effect of prolonged ischemic preconditioning on the degree of neovascularization in the distal gastric <span class="hlt">conduit</span> at the time of esophagectomy. A retrospective review of a prospectively maintained database identified 30 patients who underwent esophagectomy. The patients were divided into three groups: <span class="hlt">control</span> (no preconditioning, n = 9), partial (short gastric vessel ligation only, n = 8), and complete ischemic preconditioning (left and short gastric vessel ligation, n = 13). Microvessel counts were assessed, using immunohistologic analysis to determine the degree of neovascularization at the distal gastric margin. The groups did not differ in age, gender, BMI, pathologic stage, or cancer subtype. Ischemic preconditioning durations were 163 ± 156 days for partial ischemic preconditioning, compared to 95 ± 50 days for complete ischemic preconditioning (P = 0.2). Immunohistologic analysis demonstrated an increase in microvessel counts of 29% following partial ischemic preconditioning (P = 0.3) and 67% after complete ischemic preconditioning (P < 0.0001), compared to <span class="hlt">controls</span>. Our study indicates that prolonged ischemic preconditioning is safe and does not interfere with subsequent esophagectomy. Complete ischemic preconditioning increased neovascularization in the distal gastric <span class="hlt">conduit</span>. © 2017 Wiley Periodicals, Inc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26071111','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26071111"><span>A nerve guidance <span class="hlt">conduit</span> with topographical and biochemical cues: potential application using human neural stem cells.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jenkins, Phillip M; Laughter, Melissa R; Lee, David J; Lee, Young M; Freed, Curt R; Park, Daewon</p> <p>2015-12-01</p> <p>Despite major advances in the pathophysiological understanding of peripheral nerve damage, the treatment of nerve injuries still remains an unmet medical need. Nerve guidance <span class="hlt">conduits</span> present a promising treatment option by providing a growth-permissive environment that 1) promotes neuronal cell survival and axon growth and 2) directs axonal extension. To this end, we designed an electrospun nerve guidance <span class="hlt">conduit</span> using a blend of polyurea and poly-caprolactone with both biochemical and topographical cues. Biochemical cues were integrated into the <span class="hlt">conduit</span> by functionalizing the polyurea with RGD to improve cell attachment. Topographical cues that resemble natural nerve tissue were incorporated by introducing intraluminal microchannels aligned with nanofibers. We determined that electrospinning the polymer solution across a two electrode system with dissolvable sucrose fibers produced a polymer <span class="hlt">conduit</span> with the appropriate biomimetic properties. Human neural stem cells were cultured on the <span class="hlt">conduit</span> to evaluate its ability to promote neuronal growth and axonal extension. The nerve guidance <span class="hlt">conduit</span> was shown to enhance cell survival, migration, and guide neurite extension.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014Nanot..25n5101D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014Nanot..25n5101D"><span>In vitro evaluation of carbon-nanotube-reinforced bioprintable vascular <span class="hlt">conduits</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dolati, Farzaneh; Yu, Yin; Zhang, Yahui; De Jesus, Aribet M.; Sander, Edward A.; Ozbolat, Ibrahim T.</p> <p>2014-04-01</p> <p>Vascularization of thick engineered tissue and organ constructs like the heart, liver, pancreas or kidney remains a major challenge in tissue engineering. Vascularization is needed to supply oxygen and nutrients and remove waste in living tissues and organs through a network that should possess high perfusion ability and significant mechanical strength and elasticity. In this paper, we introduce a fabrication process to print vascular <span class="hlt">conduits</span> directly, where <span class="hlt">conduits</span> were reinforced with carbon nanotubes (CNTs) to enhance their mechanical properties and bioprintability. In vitro evaluation of printed <span class="hlt">conduits</span> encapsulated in human coronary artery smooth muscle cells was performed to characterize the effects of CNT reinforcement on the mechanical, perfusion and biological performance of the <span class="hlt">conduits</span>. Perfusion and permeability, cell viability, extracellular matrix formation and tissue histology were assessed and discussed, and it was concluded that CNT-reinforced vascular <span class="hlt">conduits</span> provided a foundation for mechanically appealing constructs where CNTs could be replaced with natural protein nanofibers for further integration of these <span class="hlt">conduits</span> in large-scale tissue fabrication.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24098649','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24098649"><span>A biosynthetic nerve guide <span class="hlt">conduit</span> based on silk/SWNT/fibronectin nanocomposite for peripheral nerve regeneration.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mottaghitalab, Fatemeh; Farokhi, Mehdi; Zaminy, Arash; Kokabi, Mehrdad; Soleimani, Masoud; Mirahmadi, Fereshteh; Shokrgozar, Mohammad Ali; Sadeghizadeh, Majid</p> <p>2013-01-01</p> <p>As a contribution to the functionality of nerve guide <span class="hlt">conduits</span> (NGCs) in nerve tissue engineering, here we report a <span class="hlt">conduit</span> processing technique through introduction and evaluation of topographical, physical and chemical cues. Porous structure of NGCs based on freeze-dried silk/single walled carbon nanotubes (SF/SWNTs) has shown a uniform chemical and physical structure with suitable electrical conductivity. Moreover, fibronectin (FN) containing nanofibers within the structure of SF/SWNT <span class="hlt">conduits</span> produced through electrospinning process have shown aligned fashion with appropriate porosity and diameter. Moreover, fibronectin remained its bioactivity and influenced the adhesion and growth of U373 cell lines. The <span class="hlt">conduits</span> were then implanted to 10 mm left sciatic nerve defects in rats. The histological assessment has shown that nerve regeneration has taken places in proximal region of implanted nerve after 5 weeks following surgery. Furthermore, nerve conduction velocities (NCV) and more myelinated axons were observed in SF/SWNT and SF/SWNT/FN groups after 5 weeks post implantation, indicating a functional recovery for the injured nerves. With immunohistochemistry, the higher S-100 expression of Schwann cells in SF/SWNT/FN <span class="hlt">conduits</span> in comparison to other groups was confirmed. In conclusion, an oriented <span class="hlt">conduit</span> of biocompatible SF/SWNT/FN has been fabricated with acceptable structure that is particularly applicable in nerve grafts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013HydJ...21.1555S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013HydJ...21.1555S"><span>Comparison of a karst groundwater model with and without discrete <span class="hlt">conduit</span> flow</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saller, Stephen P.; Ronayne, Michael J.; Long, Andrew J.</p> <p>2013-11-01</p> <p>Karst aquifers exhibit a dual flow system characterized by interacting <span class="hlt">conduit</span> and matrix domains. This study evaluated the coupled continuum pipe-flow framework for modeling karst groundwater flow in the Madison aquifer of western South Dakota (USA). Coupled <span class="hlt">conduit</span> and matrix flow was simulated within a regional finite-difference model over a 10-year transient period. An existing equivalent porous medium (EPM) model was modified to include major <span class="hlt">conduit</span> networks whose locations were constrained by dye-tracing data and environmental tracer analysis. Model calibration data included measured hydraulic heads at observation wells and estimates of discharge at four karst springs. Relative to the EPM model, the match to observation well hydraulic heads was substantially improved with the addition of <span class="hlt">conduits</span>. The inclusion of <span class="hlt">conduit</span> flow allowed for a simpler hydraulic conductivity distribution in the matrix continuum. Two of the high-conductivity zones in the EPM model, which were required to indirectly simulate the effects of <span class="hlt">conduits</span>, were eliminated from the new model. This work demonstrates the utility of the coupled continuum pipe-flow method and illustrates how karst aquifer model parameterization is dependent on the physical processes that are simulated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70048516','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70048516"><span>Comparison of a karst groundwater model with and without discrete <span class="hlt">conduit</span> flow</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Saller, Stephen P.; Ronayne, Michael J.; Long, Andrew J.</p> <p>2013-01-01</p> <p>Karst aquifers exhibit a dual flow system characterized by interacting <span class="hlt">conduit</span> and matrix domains. This study evaluated the coupled continuum pipe-flow framework for modeling karst groundwater flow in the Madison aquifer of western South Dakota (USA). Coupled <span class="hlt">conduit</span> and matrix flow was simulated within a regional finite-difference model over a 10-year transient period. An existing equivalent porous medium (EPM) model was modified to include major <span class="hlt">conduit</span> networks whose locations were constrained by dye-tracing data and environmental tracer analysis. Model calibration data included measured hydraulic heads at observation wells and estimates of discharge at four karst springs. Relative to the EPM model, the match to observation well hydraulic heads was substantially improved with the addition of <span class="hlt">conduits</span>. The inclusion of <span class="hlt">conduit</span> flow allowed for a simpler hydraulic conductivity distribution in the matrix continuum. Two of the high-conductivity zones in the EPM model, which were required to indirectly simulate the effects of <span class="hlt">conduits</span>, were eliminated from the new model. This work demonstrates the utility of the coupled continuum pipe-flow method and illustrates how karst aquifer model parameterization is dependent on the physical processes that are simulated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3787046','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3787046"><span>A Biosynthetic Nerve Guide <span class="hlt">Conduit</span> Based on Silk/SWNT/Fibronectin Nanocomposite for Peripheral Nerve Regeneration</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mottaghitalab, Fatemeh; Farokhi, Mehdi; Zaminy, Arash; Kokabi, Mehrdad; Soleimani, Masoud; Mirahmadi, Fereshteh</p> <p>2013-01-01</p> <p>As a contribution to the functionality of nerve guide <span class="hlt">conduits</span> (NGCs) in nerve tissue engineering, here we report a <span class="hlt">conduit</span> processing technique through introduction and evaluation of topographical, physical and chemical cues. Porous structure of NGCs based on freeze-dried silk/single walled carbon nanotubes (SF/SWNTs) has shown a uniform chemical and physical structure with suitable electrical conductivity. Moreover, fibronectin (FN) containing nanofibers within the structure of SF/SWNT <span class="hlt">conduits</span> produced through electrospinning process have shown aligned fashion with appropriate porosity and diameter. Moreover, fibronectin remained its bioactivity and influenced the adhesion and growth of U373 cell lines. The <span class="hlt">conduits</span> were then implanted to 10 mm left sciatic nerve defects in rats. The histological assessment has shown that nerve regeneration has taken places in proximal region of implanted nerve after 5 weeks following surgery. Furthermore, nerve conduction velocities (NCV) and more myelinated axons were observed in SF/SWNT and SF/SWNT/FN groups after 5 weeks post implantation, indicating a functional recovery for the injured nerves. With immunohistochemistry, the higher S-100 expression of Schwann cells in SF/SWNT/FN <span class="hlt">conduits</span> in comparison to other groups was confirmed. In conclusion, an oriented <span class="hlt">conduit</span> of biocompatible SF/SWNT/FN has been fabricated with acceptable structure that is particularly applicable in nerve grafts. PMID:24098649</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4281171','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4281171"><span>In Vitro Evaluation of Carbon-Nanotube-Reinforced Bioprintable Vascular <span class="hlt">Conduits</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Dolati, Farzaneh; Yu, Yin; Zhang, Yahui; De Jesus, Aribet M; Sander, Edward A.; Ozbolat, Ibrahim T.</p> <p>2014-01-01</p> <p>Vascularization of thick engineered tissue and organ constructs like the heart, liver, pancreas or kidney remains a major challenge in tissue engineering. Vascularization is needed to supply oxygen and nutrients and remove waste in living tissues and organs through a network that should possess high perfusion ability and significant mechanical strength and elasticity. In this paper, we introduce a fabrication process to print vascular <span class="hlt">conduits</span> directly, where <span class="hlt">conduits</span> were reinforced with carbon-nanotubes (CNTs) to enhance their mechanical properties and bioprintability. In vitro evaluation of printed <span class="hlt">conduits</span> encapsulated in human coronary artery smooth muscle cells (HCASMCs) was performed to characterize the effects of CNT reinforcement on the mechanical, perfusion and biological performance of the <span class="hlt">conduits</span>. Perfusion and permeability, cell viability, extracellular matrix formation and tissue histology were assessed and discussed, and it was concluded that CNT-reinforced vascular <span class="hlt">conduits</span> provided a foundation for mechanically appealing constructs where CNTs could be replaced with natural protein nanofibers for further integration of these <span class="hlt">conduits</span> in large-scale tissue fabrication. PMID:24632802</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NRL....10..264J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NRL....10..264J"><span>A nerve guidance <span class="hlt">conduit</span> with topographical and biochemical cues: potential application using human neural stem cells</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jenkins, Phillip M.; Laughter, Melissa R.; Lee, David J.; Lee, Young M.; Freed, Curt R.; Park, Daewon</p> <p>2015-06-01</p> <p>Despite major advances in the pathophysiological understanding of peripheral nerve damage, the treatment of nerve injuries still remains an unmet medical need. Nerve guidance <span class="hlt">conduits</span> present a promising treatment option by providing a growth-permissive environment that 1) promotes neuronal cell survival and axon growth and 2) directs axonal extension. To this end, we designed an electrospun nerve guidance <span class="hlt">conduit</span> using a blend of polyurea and poly-caprolactone with both biochemical and topographical cues. Biochemical cues were integrated into the <span class="hlt">conduit</span> by functionalizing the polyurea with RGD to improve cell attachment. Topographical cues that resemble natural nerve tissue were incorporated by introducing intraluminal microchannels aligned with nanofibers. We determined that electrospinning the polymer solution across a two electrode system with dissolvable sucrose fibers produced a polymer <span class="hlt">conduit</span> with the appropriate biomimetic properties. Human neural stem cells were cultured on the <span class="hlt">conduit</span> to evaluate its ability to promote neuronal growth and axonal extension. The nerve guidance <span class="hlt">conduit</span> was shown to enhance cell survival, migration, and guide neurite extension.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26369636','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26369636"><span>Assessment of Hemodynamic Conditions in the Aorta Following Root Replacement with Composite Valve-<span class="hlt">Conduit</span> Graft.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cheng, Zhuo; Kidher, Emaddin; Jarral, Omar A; O'Regan, Declan P; Wood, Nigel B; Athanasiou, Thanos; Xu, Xiao Yun</p> <p>2016-05-01</p> <p>This paper presents the analysis of detailed hemodynamics in the aortas of four patients following replacement with a composite bio-prosthetic valve-<span class="hlt">conduit</span>. Magnetic resonance image-based computational models were set up for each patient with boundary conditions comprising subject-specific three-dimensional inflow velocity profiles at the aortic root and central pressure waveform at the model outlet. Two normal subjects were also included for comparison. The purpose of the study was to investigate the effects of the valve-<span class="hlt">conduit</span> on flow in the proximal and distal aorta. The results suggested that following the composite valve-<span class="hlt">conduit</span> implantation, the vortical flow structure and hemodynamic parameters in the aorta were altered, with slightly reduced helical flow index, elevated wall shear stress and higher non-uniformity in wall shear compared to normal aortas. Inter-individual analysis revealed different hemodynamic conditions among the patients depending on the <span class="hlt">conduit</span> configuration in the ascending aorta, which is a key factor in determining post-operative aortic flow. Introducing a natural curvature in the <span class="hlt">conduit</span> to create a smooth transition between the <span class="hlt">conduit</span> and native aorta may help prevent the occurrence of retrograde and recirculating flow in the aortic arch, which is particularly important when a large portion or the entire ascending aorta needs to be replaced.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.V21B2724O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.V21B2724O"><span><span class="hlt">Conduit</span> Magma Storage during the 800 BP Quilotoa Eruption, Ecuador</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ort, M. H.; Cashman, K. V.; Di Muro, A.; Best, J. A.; Rosi, M.; Mothes, P. A.; Bustillos, J.</p> <p>2013-12-01</p> <p>The 800 BP eruption of Quilotoa produced two large ignimbrites, U1 (~5.8 km3 DRE) and U3 (~1.8 km3 DRE). These eruptions were separated by a series of much smaller eruptions over one to several weeks, as inferred from 1) the intercalation of secondary pyroclastic and debris flow deposits between U1 and U3, 2) deposits from phreatic explosions from the U1 ignimbrite surface, 3) oxidation of the upper 2 m of U1, and 4) a lack of erosion of the U1 surface. Why did the main phase of the eruption (U1) stall when eruptable magma was available? How did explosive activity stop and restart? We address these questions by examining deposits (U2) emplaced during the 'hiatus' that provide information on the conditions in the <span class="hlt">conduit</span> and vent area between explosive episodes. The lowest sub-unit, U2a, forms a series of pumiceous surge deposits found only within 5 km of the crater rim. U2b is a vitric-poor, crystal- and lithic-rich fall deposit distributed to about 15 km from the crater. U2c is a thin gray fine ash containing 2-5-mm-diameter rhyolite lapilli that is present within 6 km of the vent. Similar lapilli also occur in the lowermost few centimeters of U3 and appear to be from a dome that exploded as the new magma arrived at the surface; their presence as small ballistic fragments ties U2c to lowermost U3 in time. U2a appears to have been emplaced by episodic surges and weak fallout plumes, whereas U2b and U2c were deposited from a series of sustained eruption columns. Moreover, the lack of U2b grain-size variation with distance suggests that the grain size was determined at the vent, not by transport. FTIR analysis of CO2 and H2O in melt inclusions (MIs) indicates that a deep magma chamber (>400 MPa; ~12 km) fed U1. U2a and U2b MIs plot along vapor isopleths, suggesting equilibration at pressures to about 300 MPa as CO2 outgassed. U2b MIs have lower CO2 than U2a, perhaps indicating continued degassing during the 'hiatus'. MIs from the lower few centimeters of U3 lie along</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005BVol...67..370T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005BVol...67..370T"><span>Fault textures in volcanic <span class="hlt">conduits</span>: evidence for seismic trigger mechanisms during silicic eruptions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tuffen, Hugh; Dingwell, Don</p> <p>2005-04-01</p> <p>It is proposed that fault textures in two dissected rhyolitic <span class="hlt">conduits</span> in Iceland preserve evidence for shallow seismogenic faulting within rising magma during the emplacement of highly viscous lava flows. Detailed field and petrographic analysis of such textures may shed light on the origin of long-period and hybrid volcanic earthquakes at active volcanoes. There is evidence at each <span class="hlt">conduit</span> investigated for multiple seismogenic cycles, each of which involved four distinct evolutionary phases. In phase 1, shear fracture of unrelaxed magma was triggered by shear stress accumulation during viscous flow, forming the angular fracture networks that initiated faulting cycles. Transient pressure gradients were generated as the fractures opened, which led to fluidisation and clastic deposition of fine-grained particles that were derived from the fracture walls by abrasion. Fracture networks then progressively coalesced and rotated during subsequent slip (phase 2), developing into cataclasite zones with evidence for multiple localised slip events, fluidisation and grain size reduction. Phase 2 textures closely resemble those formed on seismogenic tectonic faults characterised by friction-<span class="hlt">controlled</span> stick-slip behaviour. Increasing cohesion of cataclasites then led to aseismic, distributed ductile deformation (phase 3) and generated deformed cataclasite zones, which are enriched in metallic oxide microlites and resemble glassy pseudotachylite. Continued annealing and deformation eventually erased all structures in the cataclasite and formed microlite-rich flow bands in obsidian (phase 4). Overall, the mixed brittle-ductile textures formed in the magma appear similar to those formed in lower crustal rocks close to the brittle-ductile transition, with the rheological response mediated by strain-rate variations and frictional heating. Fault processes in highly viscous magma are compared with those elsewhere in the crust, and this comparison is used to appraise existing models</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15565867','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15565867"><span>Photofabricated gelatin-based nerve <span class="hlt">conduits</span>: nerve tissue regeneration potentials.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gámez, Eduardo; Goto, Yoshinobu; Nagata, Kengo; Iwaki, Toru; Sasaki, Tomio; Matsuda, Takehisa</p> <p>2004-01-01</p> <p>There is a strong demand for development of nerve guide <span class="hlt">conduit</span> with prompt nerve regeneration potential for injury-induced nerve defect. Prior to study on nerve tissue engineering using Schwann cells or nerve stem cells, the effectiveness of photofabricated scaffolds based on photocurable gelatin was examined. This study describes the evaluation of in vivo nerve tissue regeneration potentials of three custom-designed and -fabricated prostheses (inner diameter, 1.2 mm; outer diameter, 2.4 mm; wall thickness, 0.60 mm; and length, 15 mm) made of photocured gelatin: a plain photocured gelatin tube (model I), a photocured gelatin tube packed with bioactive substances (laminin, fibronectin, and nerve growth factor) coimmobilized in a photocured gelatin rod (model II), and a photocured gelatin tube packed with bioactive substances coimmobilized in multifilament fibers (model III). These prostheses were implanted between the proximal and distal stumps 10 mm of the dissected right sciatic nerve of 70 adult male Lewis rats for up to 1 year. The highest regenerative potentials were found using the model III prosthesis, followed by the model II prosthesis. Markedly retarded neural regeneration was observed using the model I prosthesis. These were evaluated from the viewpoints of functional recovery, electrophysiological responses, and tissue morphological regeneration. The significance of the synergistic cooperative functions of multifilaments, which serve as a platform that provides contact guidance to direct longitudinal cell movement and tissue ingrowth and as a cell adhesive matrix with high surface area, and immobilized bioactive substances, which enhance nerve regeneration via biological stimulation, is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMDI34A..03F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMDI34A..03F"><span>Fluid dynamics of active heterogeneities in a mantle plume <span class="hlt">conduit</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Farnetani, C. G.; Limare, A.; Hofmann, A. W.</p> <p>2015-12-01</p> <p>Laboratory experiments and numerical simulations indicate that the flow of a purely thermal plume preserves the azimuthal zonation of the source region, thus providing a framework to attribute a deep origin to the isotopic zonation of Hawaiian lavas. However, previous studies were limited to passive heterogeneities not affecting the flow. We go beyond this simplification by considering active heterogeneities which are compositionally denser, or more viscous, and we address the following questions: (1) How do active heterogeneities modify the axially symmetric velocity field of the plume <span class="hlt">conduit</span>? (2) Under which conditions is the azimuthal zonation of the source region no longer preserved in the plume stem? (3) How do active heterogeneities deform during upwelling and what is their shape once at sublithospheric depths? We conducted both laboratory experiments, using a Particle Image Velocimetry (PIV) to calculate the velocity field, and high resolution three-dimensional simulations where millions of tracers keep track of the heterogeneous fluid. For compositionally denser heterogeneities we cover a range of buoyancy ratios 0<B<2, where B=Δρchemical/Δρthermal and ρ is density; for more viscous heterogeneities, the range of viscosity ratios is 0<λ<20, where λ=ηheterogeneity/ηfluid and η is viscosity. The initial heterogeneity has the arbitrary shape of a sphere and we vary its volume and its distance from the plume axis. We find that by increasing λ, the shape of the heterogeneity changes from filament-like to blob-like characterized by internal rotation and little stretching. By increasing B the heterogeneity tends to spread at the base of the plume stem and to rise as a tendril close to the axis, so that the initial zonation may be poorly preserved. We also find that the plume velocity field can be profoundly modified by active heterogeneities, and we explore the relation between strain rates and the evolving shape of the upwelling heterogeneity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11091239','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11091239"><span>Compliance properties of <span class="hlt">conduits</span> used in vascular reconstruction.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tai, N R; Salacinski, H J; Edwards, A; Hamilton, G; Seifalian, A M</p> <p>2000-11-01</p> <p>Compliance mismatch between native artery and prosthetic graft used for infrainguinal bypass is implicated in the aetiology of graft failure. The aim was to quantify the elastic properties of a new compliant poly(carbonate)polyurethane (CPU) vascular graft, and to compare the compliance properties of grafts made from CPU, expanded polytetrafluoroethylene (ePTFE), Dacron and human saphenous vein with that of human muscular artery. A pulsatile flow phantom was used to perfuse vessel and prosthetic graft segments at physiological pulse pressure and flow. Intraluminal pressure was measured using a Millar Mikro-tip catheter transducer and vessel wall motion was determined with duplex ultrasonography using an echo-locked wall-tracking system. Diametrical compliance and a stiffness index were then calculated for each type of <span class="hlt">conduit</span> over mean pressures ranging from 30 to 100 mmHg by 10-mmHg increments. The compliance values of CPU and artery (mean over the pressure range) were similar (mean(s.d.) 8.1(0.4) and 8.0(5.9) per cent per mmHg x 10(-2) respectively), although the elastic behaviour of artery was anisotropic unlike CPU, which was isotropic. Dacron and ePTFE grafts had lower compliance values (1.8(1.2) and 1.2(0.3)per cent per mmHg x 10(-2) respectively, averaged over the pressure range). In both these cases, compliance and stiffness differed significantly from that of artery over a mean pressure range of 30-90 mmHg. Human saphenous vein exhibited anisotropic behaviour and, although compliant at low pressure (30 mmHg), was markedly incompliant at higher pressures. Compliant polyurethane grafts offer a greater degree of compliance match than either ePTFE or Dacron.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10190603','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10190603"><span>Current distribution in Cable-In-<span class="hlt">Conduit</span> Conductors</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ferri, M.A.</p> <p>1994-05-01</p> <p>A numerical study of the current distribution in Cable-In-<span class="hlt">Conduit</span> Conductors (CICC`s) experiencing linearly ramping transport currents and transverse magnetic fields was conducted for both infinitely long, periodic cables and finite length cables terminated in low resistance joints. The goal of the study was to gain insight into the phenomenon known as Ramp Rate Limitation, an as yet unexplained correspondence between maximum attainable current and the ramp time taken to reach that current in CICC superconducting magnets. A discrete geometric model of a 27 strand multiply twisted CICC was developed to effectively represent the flux linkages, mutual inductances, and resistive contact points between the strands of an experimentally tested cable. The results of the numerical study showed that for fully periodic cables, the current imbalances due to ramping magnetic fields and ramping transport currents are negligible in the range of experimentally explored operating conditions. For finite length, joint terminated cables, however, significant imbalances can exist. Unfortunately, quantitative results are limited by a lack of knowledge of the transverse resistance between strands in the joints. Nonetheless, general results are presented showing the dependency of the imbalance on cable length, ramp time, and joint resistance for both ramping transverse magnet fields and ramping transport currents. At the conclusion of the study, it is suggested that calculated current imbalances in a finite length cable could cause certain strands to prematurely ``quench`` -- become non-superconducting --thus leading to an instability for the entire cable. This numerically predicted ``current imbalance instability`` is compared to the experimentally observed Ramp Rate Limitation for the 27 strand CICC sample.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25647385','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25647385"><span>Polytetrafluoroethylene pulmonary valve <span class="hlt">conduit</span> implantation for chronic pulmonary insufficiency.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Quintessenza, James A</p> <p>2014-12-01</p> <p>Pulmonary valve replacement in patients with congenital cardiac disease is now being performed with more liberal indications in light of the data that chronic pulmonary insufficiency is not a benign lesion. The beneficial effects of valve replacement with low operative mortality and morbidity support this approach. Many options exist for a pulmonary valve prosthesis, which underscores the fact that there is no ideal valve available. Our efforts are focussed around a synthetic valve that avoids the bio-degeneration of a bio-prosthesis and avoids the need for life-long coumadin. We developed a bicuspid (bileaflet) polytetrafluoroethylene valve design, which has now gone through three major revisions in >200 patients over 14 years. We began the experience utilising a polytetrafluoroethylene hand-sewn bicuspid valve in the right ventricular outflow tract, initially using 0.6 mm and more recently 0.1 mm polytetrafluoroethylene. The 0.1 mm thickness material functions well as a leaflet, maintaining a relatively thin and flexible nature. It does not calcify or initiate thromboses at least for the first several years. We identified issues with dehiscence of the leaflet from the right ventricular outflow tract muscle, especially in the larger, potentially expansive right ventricular outflow tracts, and this prompted our latest design change to place the valve within a polytetrafluoroethylene tube. This current version of the polytetrafluoroethylene valve <span class="hlt">conduit</span> has excellent short-to-intermediate-term function. Further follow-up is necessary to determine late durability and life-long valve-related procedural risk for our patients.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17290376','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17290376"><span>Diverse types of epineural <span class="hlt">conduits</span> for bridging short nerve defects. An experimental study in the rabbit.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ignatiadis, Ioannis A; Yiannakopoulos, Christos K; Barbitsioti, Antonia D; Avram, Adrian M; Patralexis, Haralambos G; Tsolakis, Charilaos K; Papalois, Apostolos E; Xenakis, Theodoros H; Beris, Alexandros E; Soucacos, Panayiotis N</p> <p>2007-01-01</p> <p>In this study the process of peripheral nerve regeneration through an epineural flap <span class="hlt">conduit</span> was examined using four groups of 126 New Zealand rabbits. There were three study groups (A, B, and C) and 1 <span class="hlt">control</span> group (D). A 10-mm long sciatic nerve defect was bridged either with 3 variations of an epineural flap (Groups A, B, and C) or with a nerve autograft (Group D). Animals from all groups were examined 21, 42, and 91 days postoperatively to evaluate nerve regeneration employing light microscopy and immunocytochemistry. Nerve regeneration was studied in transverse sections at 3, 6, and 9 mm from the proximal stump. The gastrocnemius muscle contractility was also examined prior to euthanasia at 91 days postsurgery in all groups using electromyography. Immunohistochemical, histochemical and functional evaluation showed the presence of nerve regeneration resembling the <span class="hlt">control</span> group D, especially in group A, where an advancement epineural flap was used. In this experimental model an epineural flap can be used to bridge a nerve defect successfully.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1817736H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1817736H"><span><span class="hlt">Conduit</span> evolution during the Avellinio Plinian eruption (Vesuvius): insights from fieldwork, lithic grain size distributions and modelling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hanson, Jonathan; Rust, Alison; Phillips, Jeremy; Sulpizio, Roberto; Engwell, Samantha; Costa, Antonio</p> <p>2016-04-01</p> <p>Large-scale explosive eruptions are modulated by a combination of magmatic and <span class="hlt">conduit</span> processes, including changes in the geometry of the <span class="hlt">conduit</span> as host rocks are eroded from the <span class="hlt">conduit</span> walls and vent region. This study of deposits 1-45 km from source of the main, quasi-steady Plinian phases of the 3949 ± 10 yBP Avellino eruption of Vesuvius (EU2 and EU3) demonstrates the potential for measurements of lithics and xenoliths to constrain subsurface eruption processes. The lithics comprise volcanic rocks derived from the upper ˜2700 m of the <span class="hlt">conduit</span>, carbonates from the lower <span class="hlt">conduit</span> and magma reservoir wall rocks. The lithics (free clasts) are thought to be incorporated into the erupting mixture by <span class="hlt">conduit</span> wall implosion around and above the fragmentation depth as well as shallow vent spalling, whilst xenoliths are interpreted to result from viscous shear stresses applied to the <span class="hlt">conduit</span> walls pre-fragmentation. The lithology of xenoliths indicates that they are sourced from relatively deep in the <span class="hlt">conduit</span>, and their scarcity indicates that there is only minor <span class="hlt">conduit</span> erosion below magma fragmentation during the Plinian eruptions. In contrast total lithic volumes calculated for EU2 and EU3 are 0.002 and 0.02 km3, respectively, which corresponds to 8 % and 18 % of the total erupted volume. Lava lithics dominate, making up 69 and 74 % of the total lithic volume for EU2 and EU3, respectively. The majority of <span class="hlt">conduit</span> erosion occurred above the fragmentation depth, in the upper few kilometers of the <span class="hlt">conduit</span>, and scales approximately with the increase in mass discharge rate between the two phases. Individual component (total lithic, carbonate, lava) Lithic Total Grain Size Distributions (L-TGSDs) provide insights into rock failure mechanisms. The fractal dimensions of the majority of the L-TGSDs are approximately 2 (grain size in φ against log2 no. of grains), inferred to be the result of <span class="hlt">conduit</span> implosion modified by initial rock characteristics. The lava lithics from</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20737555','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20737555"><span>Characteristics and biocompatibility of a biodegradable genipin-cross-linked gelatin/β-tricalcium phosphate reinforced nerve guide <span class="hlt">conduit</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yang, Yi-Chin; Shen, Chiung-Chyi; Huang, Tsung-Bin; Chang, Shun-Hsung; Cheng, Hsu-Chen; Liu, Bai-Shuan</p> <p>2010-10-01</p> <p>To modulate the mechanical properties of nerve guide <span class="hlt">conduit</span> for surgical manipulation, this study develops a biodegradable composite containing genipin cross-linked gelatin annexed with β-tricalcium phosphate ceramic particles as a nerve guide material. The <span class="hlt">conduit</span> was dark bluish and round with a rough and compact outer surface compared to the genipin cross-linked gelatin <span class="hlt">conduit</span> (without β-tricalcium phosphate). Water uptake and swelling tests indicate that the <span class="hlt">conduit</span> noticeably increases the stability in water, and the hydrated <span class="hlt">conduit</span> does not collapse and stenose. The <span class="hlt">conduit</span> has a sufficiently high level of mechanical properties to serve as a nerve guide. After subcutaneous implantation on the dorsal side of a rat, the degraded <span class="hlt">conduit</span> only evokes a mild tissue response, and the formation of a very thin fibrous capsule surrounds the <span class="hlt">conduit</span>. This paper assesses the effectiveness of the <span class="hlt">conduit</span> as a guidance channel when we use it to repair a 10 mm gap in the rat's sciatic nerve. The experimental results show no gross inflammatory reactions of the peripheral nerve tissues at the implantation site in either group. In overall gross examination, the diameter of the intratubular and newly formed nerve fibers in the <span class="hlt">conduits</span> exceeds that of the silicone tubes during the implantation period. The quantitative results indicate the superiority of the <span class="hlt">conduits</span> over the silicone tubes. This study microscopically observes the nerve regeneration in the tissue section at the middle region of all implanted <span class="hlt">conduits</span>. Therefore, the histomorphometric assessment demonstrates that the <span class="hlt">conduit</span> could be a candidate for peripheral nerve repair.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.H43C1048Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.H43C1048Z"><span>Geophysical Methods for Locating Karst <span class="hlt">Conduits</span> in Cane Run Watershed, Central Kentucky</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhu, J.; Paylor, R.; Currens, J. C.; Dinger, J. S.</p> <p>2009-12-01</p> <p>Cane Run watershed in central Kentucky was listed by the Kentucky Division of Water as one of four focus watersheds for clean-up under the State’s nonpoint-source pollution program. This watershed is degraded by pathogens, nutrients, siltation, and organic enrichment. The sources of pollution include both municipal point sources and nonpoint agricultural and nonagricultural sources. The relative contribution of different parts of the watershed to the contamination is not well understood, however. The geology of Cane Run watershed consists of Ordovician thin-bedded limestone with sparse interbeds of shale. The landscape is dominated by karst features such as sinkholes and springs. Cane Run only flows during times of significant rainfall, usually in the spring of the year. The remainder of the year, most water is recharged to a karst <span class="hlt">conduit</span> system that leads from Lexington, Ky to Royal Spring, as demonstrated by groundwater tracing. Royal Spring is the major water supply for Georgetown in Scott County, Ky. We attempted to locate the karst <span class="hlt">conduit</span> so that groundwater flowing through the <span class="hlt">conduit</span> could be monitored. These monitoring data are essential for assessing the effectiveness of remediation plans. In 2008, based on geology, karst features, and hydrogeology, an initial round of electrical-resistivity and spontaneous-potential geophysical surveys were conducted to help pinpoint the location of the <span class="hlt">conduit</span> at three sites. Fifteen exploratory boreholes were drilled on the basis of the geophysical results. The boreholes confirmed the geophysical surveys had located minor mud-filled <span class="hlt">conduits</span> that were interpreted as tributaries to the main <span class="hlt">conduit</span>. Another round of 2D and 3D electrical resistivity surveys were conducted in 2009 to search for the main <span class="hlt">conduit</span>. The analysis of this round of surveys resulted in one promising site that is suspected to be in close proximity to the <span class="hlt">conduit</span>. A time-lapse 2D electrical resistivity survey in conjunction with calcium chlorite</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21976180','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21976180"><span>Nerve growth factor combined with an epineural <span class="hlt">conduit</span> for bridging a short nerve gap (10 mm). A study in rabbits.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Barmpitsioti, Antonia; Konofaos, Petros; Ignatiadis, Ioannis; Papalois, Apostolos; Zoubos, Aristides B; Soucacos, Panagiotis N</p> <p>2011-10-01</p> <p>The purpose of this study was to evaluate the effect of direct administration of nerve growth factor (NGF) into an epineural <span class="hlt">conduit</span> across a short nerve gap (10 mm) in a rabbit sciatic nerve model. The animals were divided into two groups. In group 1, n = 6, a 10-mm defect was created in the sciatic nerve and bridged with an epineural flap. A dose of 1 μg of NGF was locally administered daily for the first 21 days. NGF administration was made inside the epineural flap using a silicone reservoir connected to a silicone tube. In group 2, n = 6, the 10-mm defect was bridged with a nerve graft. This group did not receive any further treatment. At 13 weeks, all animals, before euthanasia, underwent electromyography (EMG) studies and then specimen sent for histology morphometric analysis. NGF administration ensured a significantly increased average number of myelinated axons per μm(2) (P = 0.028) and promoted fiber maturation (P = 0.031) and better EMG results (P = 0.046 for latency P = 0.048 for amplitude), compared with the <span class="hlt">control</span> group. Although nerve grafts remain the gold standard for peripheral nerve repair, NGF-treated epineural <span class="hlt">conduits</span> represent a good alternative, particularly when an unfavorable environment for nerve grafts is present.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002PlST....4.1163C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002PlST....4.1163C"><span>A 600-m Jacketing Line of Cable-in-<span class="hlt">conduit</span> Conductor (CICC) and the First 600-m Dummy Cable</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Si-yue; Wu, Jie-feng; Chen, Xing-qian; Zhang, Pin; He, Wei; Wang, Hai-jing; Xu, Xue-fu; Yi, Zian; Gao, Da-ming</p> <p>2002-02-01</p> <p>A cable-in-<span class="hlt">conduit</span> conductor (CICC) production line was designed and constructed in Institute of Plasma Physics of Chinese Academy of Sciences (IPPCAS) by the end of 2000. It can produce a length of 600 meters and three kinds of sections of 20.8±0.1 × 20.8±0.1, 20.4±0.1 × 20.4±0.1 and 18.6 ± 0.1 × 18.6 ± 0.1 mm2. If the rollers of the shaping machine are changed, it can also produce other sizes of CICCs. So-called inserting-cable technology is adopted in this production line, where the procedures consist of tube pre-treatment (cleaning, pressure and leakage testing, end cutting), <span class="hlt">conduits</span> butt-welding, six kinds of quality checking (endoscopy, dye penetration, pressure <span class="hlt">control</span>, leakage testing, ultrasonic inspection and x-ray testing), cable inserting, shaping (compacting & squaring), pre-bending & winding and final checking. Now all the instruments and facilities required for these technologies have been installed and got ready. Some key technologies have been explored and good results obtained. Some short samples were produced and a 600 meters long sample was made out in August, 2001.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27087603','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27087603"><span>The Effects of Losartan in Preserving the Structural Integrity of Decellularized Small Diameter Vascular Allograft <span class="hlt">Conduit</span> Implants In Vivo.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lee, Seung Hyun; Lee, Byoung Wook; Kim, Seong Who; Choo, Suk Jung</p> <p>2017-01-01</p> <p>Decellularization is a proposed method of preparing nonautologous biological arterial vascular scaffolding; however, the fate of the supporting medial elastic fiber, which is important in preserving the vascular structural integrity, is uncertain. The influence of losartan on preserving the medial elastic fiber integrity in decellularized small diameter vascular <span class="hlt">conduits</span> (SDVC) was investigated. Decellularized infrarenal abdominal aortic allografts were implanted in Sprague-Dawley rats treated either with (study rats, n = 6) or without oral losartan (<span class="hlt">control</span> rats, n = 6) and graded 8 weeks later according to a remodeling scoring system (1-mild, 2-moderate, 3-severe) which we devised based on the intimal hyperplasia degree, morphologic changes, and elastic fiber fragmentation of the <span class="hlt">conduits</span>. DAPI immunohistochemistry analysis was performed in 47 (25 decellularization only and 22 losartan treatment) cross-sectional slide specimens. The losartan versus decellularization only SDVC showed a significantly lower medial elastic fragmentation score (1.32 vs. 2.24, P < 0.001), superior medial layer preservation, and relatively more normal appearing intimal cellular morphology. The results suggested rats receiving decellularized SDVCs treated with losartan may yield superior medial layer elastic fiber preservation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19663865','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19663865"><span>Highly permeable genipin-cross-linked gelatin <span class="hlt">conduits</span> enhance peripheral nerve regeneration.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chang, Ju-Ying; Ho, Tin-Yun; Lee, Han-Chung; Lai, Yen-Liang; Lu, Ming-Chin; Yao, Chun-Hsu; Chen, Yueh-Sheng</p> <p>2009-12-01</p> <p>Here we have evaluated peripheral nerve regeneration with a porous biodegradable nerve <span class="hlt">conduit</span> (PGGC), which was made from genipin-cross-linked gelatin. To examine the effect of pores, nonporous genipin-cross-linked gelatin <span class="hlt">conduit</span> (GGC) was considered as the <span class="hlt">control</span>. Both the PGGC and the GGC were dark blue in appearance with a concentric and round lumina. The PGGC featured an outer surface with pores of variable size homogeneously traversing, and a partially fenestrated inner surface connected by an open trabecular meshwork. The GGC had a rough outer surface whereas its inner lumen was smooth. Both PGGCs and GGCs had similar hydrophilicity on condition of the same material and cross-linking degree. The porosity of PGGCs and GGCs was 90.8 +/- 0.9% and 24.3 +/- 2.9%, respectively. The maximum tensile force of the GGCs (0.12 +/- 0.06 kN) exceeded that of the PGGCs (0.03 +/- 0.01 kN), but the PGGCs had a higher swelling ratio than GGCs at 0.5, 1, 3, 6, 12, 24, 48, 60, 72, and 84 h after soaking in deionized water. Cytotoxic testing revealed the soaking solutions of both of the tube composites would not produce cytotoxicity to cocultured Schwann cells. After subcutaneous implantation on the dorsal side of the rat, the PGGC was degraded completely after 12 weeks of implantation whereas a thin tissue capsule was formed encapsulating the partially degraded GGC. Biodegradability of both of the tube groups and their effectiveness as a guidance channel were examined as they were used to repair a 10 mm gap in the rat sciatic nerve. As a result, fragmentation of the GGC was still seen after 12 weeks of implantation, yet the PGGC had been completely degraded. Histological observation showed that numerous myelinated axons had crossed over the gap region in the PGGCs after 8 weeks of implantation despite only few myelinated axons and unmyelinated axons mostly surrounded by Schwann cells seen in the GGCs. In addition, the regenerated nerves in the PGGCs presented a significantly</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFM.V24B..03S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFM.V24B..03S"><span>Unzen Scientific Drilling Project: Challenging drilling operation into the magmatic <span class="hlt">conduit</span> shortly after eruption</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sakuma, S.; Nakada, S.; Uto, K.</p> <p>2004-12-01</p> <p>Drilling operation was aimed at penetration into the core of the volcano 8 years after eruption of Unzen, including directional drilling in high temperature and with high inclination. The project started with fixing drilling site. Scientists and drilling engineers agreed to settle it at the northern slope of Mt. Unzen at 840 m asl, and the drilling target was set at sea level. Drilling operation was started in Feb. 2003. In the shallow section, frequent lost circulation and accidental side-track occurred due to the unconsolidated zone, and caused_@many troubles. Although the drilling was delayed, we succeeded in drilling down to 396m with the inclination of 25 degree in 17-1/2 inch hole and 13-3/8 inch casing section. 12-1/4 inch hole was drilled using TDS, EM-MWD, and DHM. When the inclination was built up to 75 degree at 795 m, we changed the drilling mode of trajectory <span class="hlt">control</span> to keep the angle. A large fracture of total loss was encountered at 807m, and serious cuttings bed occurred. The latter made the drilling impossible to continue. Then, we inserted 9-5/8 inch casing down to 796 m. Trajectory correction runs was completed in 8-5/8 inch hole, and 7 inch casing was set down to 1550m. In 6-1/4 inch hole, though EM-MWD and DHM were not used, drilling inclination and azimuth were stable. Spot coring was started at 1582 m, the levels of spot coring depth were chosen based on the data of temperature measurement and cuttings observation. Though the drilling exceeded 1800m, the original target depth, drilling was continued, because we could not encounter the high temperature <span class="hlt">conduit</span> at that time. Finally, the well reached the 1995 m, and succeeded in taking cores highly probable of magmatic <span class="hlt">conduit</span> in July 2004. We could carry out geophysical logging mostly throughout the whole sections. Spot coring were done at 16 times; its total length was 75m. Although the highest measured temperature was 155 deg. C, the formation temperature may reach at least 200 deg. C. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18..815A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18..815A"><span>The effect of shear on permeability in a volcanic <span class="hlt">conduit</span>: a case study at Unzen volcano, Japan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ashworth, James; Lavallée, Yan; Wallace, Paul; Lamur, Anthony; Kendrick, Jackie; Miwa, Takahiro</p> <p>2016-04-01</p> <p>The efficiency of outgassing at volcanoes is a function of permeability, and exerts a major influence on the type of eruptive behaviour exhibited. Understanding how shear affects the permeability profile across volcanic <span class="hlt">conduits</span> is therefore a key part of understanding volcanic processes and the associated hazards. During the final months of the 1990-1995 eruption of Unzen volcano in southern Japan, extrusion of a dacite spine followed a period of endogenous dome growth. Many of the resulting formations are relatively accessible, allowing for the study of a variety of associated deformation phenomena. One of these formations, a ~6 m wide block, is a section of the extruded spine, that forms the basis for this study on shallow <span class="hlt">conduit</span> processes. It displays a textural gradation from highly sheared rock to rock with negligible deformation, and is bounded at the high shear end by an agglutinated block of gouge that is thought to represent the <span class="hlt">conduit</span> margin. A multi-faceted approach was taken to investigate the variation of permeability across the spine and its implications for processes occurring within the <span class="hlt">conduit</span>. The permeability was measured at several points along the exposed surface of the spine transect using a field permeameter. Sample blocks from four of these locations were collected and tested in the lab using a hydrostatic pressure vessel water-flow permeameter and categorized as: gouge; highest shear; moderate shear; negligible shear. Each block was tested in three orthogonal axes: one perpendicular to observed shear; and two in the plane of shear. For each of these rocks, permeability and porosity measurements were made at a wide range of effective pressures (5 to 100 MPa), using a <span class="hlt">controlled</span> upstream/downstream pore pressure gradient of 0.5 MPa (at an average pore pressure of 1.25 MPa). Thin sections of each sample were also taken prepared and analysed to describe the primary microstructures <span class="hlt">controlling</span> the permeability of the rock. Textural analysis</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26583672','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26583672"><span>Gut Hormone Suppression Increases Food Intake After Esophagectomy With Gastric <span class="hlt">Conduit</span> Reconstruction.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Elliott, Jessie A; Jackson, Sabrina; King, Sinead; McHugh, Ruth; Docherty, Neil G; Reynolds, John V; le Roux, Carel W</p> <p>2015-11-01</p> <p>To characterize the gut hormone profile and determine the effect of satiety gut hormone blockade on food intake in disease-free postesophagectomy patients. Improved oncologic outcomes for esophageal cancer have resulted in increased survivorship and a focus on health-related quality of life. Anorexia and early satiety are common, but putative causative factors, in particular the gut-brain hormonal axis, have not been systematically studied. In a double-blind, placebo-<span class="hlt">controlled</span>, randomized crossover study, disease-free patients at least 1 year postresection and gastric <span class="hlt">conduit</span> reconstruction received either 1 mL 0.9% saline or 1 mL (100 μg) octreotide acetate subcutaneously followed by a standardized ad libitum meal on each of two assessments. Fasting and postprandial plasma glucagon-like peptide 1 (GLP-1), peptide YY (PYY), and ghrelin immunoreactivity were measured. Gut hormone responses and calorie intake postsaline versus octreotide were compared between experimental and <span class="hlt">control</span> groups. Eighteen subjects [esophagectomy (ES), n = 10, 2.4 ± 0.75 years postresection; and unoperated <span class="hlt">control</span> subjects, n = 8] were studied. ES demonstrated significant weight loss at 3, 6, 12, and 24 months postoperatively (all P < 0.05). Ghrelin levels were similar (P = 0.58) for both groups, but postprandial GLP-1 and PYY responses were significantly (P < 0.001) greater among ES as compared with <span class="hlt">controls</span>. After octreotide, ad libitum calorie intake increased among ES (1.5 ± 0.2 fold-change, P = 0.02) but not <span class="hlt">controls</span> (1.1 ± 0.1 fold-change, P = 0.30). ES demonstrated an exaggerated postprandial satiety gut hormone response that was attenuated by octreotide, thus identifying a potential therapeutic target to modulate in the ES patient with early satiety.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22054813','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22054813"><span>[Large diameter nerve <span class="hlt">conduits</span> use in the upper limb: report of four cases and literature review].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jardin, E; Huard, S; Chastel, R; Uhring, J; Obert, L</p> <p>2011-12-01</p> <p>Defects of the median, ulnar or radial nerves in the forearm, can be treated by conventional nerve grafts, or by interposing a synthetic guide such as nerve <span class="hlt">conduits</span>. Wounds without nerve loss treated with simple suture may be supplemented by sleeving to prevent the nerve irritation symptoms using a nerve <span class="hlt">conduit</span> or a vein sleeve. We studied the results of nerve <span class="hlt">conduits</span> in both cases in a single-center retrospective study. Four patients underwent surgery with placement of a nerve <span class="hlt">conduit</span> in the forearm, between May 2007 and January 2011. All patients were reviewed by the same examiner. Pain, tenderness, motor (Medical Research Council classification, MRC), time to return to work and self-evaluation by the patient were measured. The averages of these data were calculated and compared with results of other studies in the literature, the nerve grafts for defects and the Socket joints for venous ulcers. The decrease is on average 30 months (2 years). The defect never exceeds 40mm and is 22mm on average. According to the classification MRC, sensitivity found after inserting nerve <span class="hlt">conduits</span> in the forearm after a defect is excellent (S4) for two of three patients and good (S3) for the third. Motor results were very good (M4 and M3 for one patient) andM2 for the other. As for the insertion of a nerve <span class="hlt">conduit</span> as a sleeve, the result is good in terms of sensitivity (S3) and excellent in terms of motor (M5) for our case in the study. For our small group of patients with neuroma we obtained, results similar to those published in the literature with conventional techniques. The nerve <span class="hlt">conduits</span> seem to give results similar to conventional techniques, in situations of defects or neuromasin the forearm, with a diameter greater than 2mm, but defects of less than 30mm. Copyright © 2011 Elsevier Masson SAS. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014HESSD..11.6519P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014HESSD..11.6519P"><span>Evolution of karst <span class="hlt">conduit</span> networks in transition from pressurised flow to free surface flow</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Perne, M.; Covington, M. D.; Gabrovšek, F.</p> <p>2014-06-01</p> <p>We present a novel modelling approach to study the evolution of <span class="hlt">conduit</span> networks in soluble rocks. Unlike the models presented so far, the model allows a transition from pressurised (pipe) flow to a free surface (open channel) flow in evolving discrete <span class="hlt">conduit</span> networks. It calculates flow, solute transport and dissolutional enlargement within each time step and steps through time until a stable flow pattern establishes. The flow in each time step is calculated by calling the EPA Storm Water Management Model (EPA SWMM), which efficiently solves the 1-D Saint Venant equations in a network of <span class="hlt">conduits</span>. We present several cases with low dip and sub-vertical networks to demonstrate mechanisms of flow pathway selection. In low dip models the inputs were randomly distributed to several junctions. The evolution of pathways progresses upstream: initially pathways linking outlets to the closest inputs evolve fastest because the gradient along these pathways is largest. When a pathway efficiently drains the available recharge, the head drop along the pathway attracts flow from the neighbouring upstream junctions and new connecting pathways evolve. The mechanism progresses from the output boundary inwards until all inputs are connected to the stable flow system. In the pressurised phase, each junction is drained by at least one <span class="hlt">conduit</span>, but only one <span class="hlt">conduit</span> remains active in the vadose phase. The selection depends on the initial geometry of a junction, initial distribution of diameters, the evolution in a pressurised regime, and on the dip of the <span class="hlt">conduits</span>, which plays an important role in vadose entrenchment. In high dip networks, the vadose zone propagates downwards and inwards from the rim of the massif. When a network with randomly distributed initial diameters is supplied with concentrated recharge from the adjacent area, the sink point regresses up upstream along junctions connected to the prominent pathways. Large conductive structures provide deep penetration of high</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002GGG.....3.1037M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002GGG.....3.1037M"><span>Insights into volcanic <span class="hlt">conduit</span> flow from an open-source numerical model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mastin, Larry G.</p> <p>2002-07-01</p> <p>Numerical models that calculate the fluid dynamics of explosive volcanic eruptions have been used with increasing frequency to understand volcanic processes and evaluate volcanic hazards. Yet those who develop such models rarely make them publicly available so that they can be verified, used, and possibly improved by other scientists. In this paper I present a visual, interactive, open-source numerical model that calculates steady state flow of magma and gas in vertical eruptive <span class="hlt">conduits</span> and contains user-friendly utilities for quickly determining physical, thermodynamic, and transport properties of silicate melts, H2O gases, and melt-gas-crystal mixtures. The model represents an advance over previously published <span class="hlt">conduit</span> models by incorporating a non-Arrhenian viscosity relation for hydrous silicate melts, a relation between viscosity and volume fraction of gas that depends on Capillary number, and adiabatic temperature changes in the mixture using established thermodynamic relations for melts and H2O gas, respectively. Volcanologists who have not had access to <span class="hlt">conduit</span> models have frequently approximated <span class="hlt">conduit</span> flow using an analytical equation for incompressible, laminar, Newtonian pipe flow, which predicts that the mass flux is proportional to the fourth power of <span class="hlt">conduit</span> radius and inversely proportional to mixture viscosity. The model presented here, which is not much more difficult to use than a back-of-the-envelope calculation, shows that the pipe-flow approximation significantly overestimates the sensitivity of mass flux to both <span class="hlt">conduit</span> radius and mixture viscosity. Results from the model also show that viscous heating in the lower <span class="hlt">conduit</span>, which is not considered in most other models, may increase the mass flux of large silicic eruptions by several percent and decrease the viscosity of the mixture at the fragmentation depth by a few tens of percent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23806037','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23806037"><span>Diminished contractile responses of isolated <span class="hlt">conduit</span> arteries in two rat models of hypertension.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zemancíková, Anna; Török, Jozef</p> <p>2013-08-31</p> <p>Hypertension is accompanied by thickening of arteries, resulting in marked changes in their passive and active mechanical properties. The aim of this study was to demonstrate that the large <span class="hlt">conduit</span> arteries from hypertensive individuals may not exhibit enhanced contractions in vitro, as is often claimed. Mechanical responses to vasoconstrictor stimuli were measured under isometric conditions using ring arterial segments isolated from spontaneously hypertensive rats, N(omega)-nitro-L-arginine methyl ester (L-NAME)-treated Wistar rats, and untreated Wistar rats serving as normotensive <span class="hlt">control</span>. We found that thoracic aortas from both types of hypertensive rats had a greater sensitivity but diminished maximal developed tension in response to noradrenaline, when compared with that from normotensive rats. In superior mesenteric arteries, the sensitivity to noradrenaline was similar in all examined rat groups but in L-NAME-treated rats, these arteries exhibited decreased active force when stimulated with high noradrenaline concentrations, or with 100 mM KCl. These results indicate that hypertension leads to specific biomechanical alterations in diverse arterial types which are reflected in different modifications in their contractile properties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18155135','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18155135"><span>Peripheral nerve regeneration within an asymmetrically porous PLGA/Pluronic F127 nerve guide <span class="hlt">conduit</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Oh, Se Heang; Kim, Jun Ho; Song, Kyu Sang; Jeon, Byeong Hwa; Yoon, Jin Hwan; Seo, Tae Beom; Namgung, Uk; Lee, Il Woo; Lee, Jin Ho</p> <p>2008-04-01</p> <p>Asymmetrically porous tubes with selective permeability and hydrophilicity as nerve guide <span class="hlt">conduits</span> (NGCs) were fabricated using poly(lactic-co-glycolic acid) (PLGA) and Pluronic F127 by a modified immersion precipitation method. The inner surface of the tube had nano-size pores ( approximately 50nm) which can effectively prevent from fibrous tissue infiltration but permeate nutrients and retain neurotrophic factors, while the outer surface had micro-size pores ( approximately 50microm) which can allow vascular ingrowth for effective supply of nutrients into the tube. From the animal study using a rat model, the hydrophilized PLGA/F127 (3wt%) tube showed better nerve regeneration behavior than the <span class="hlt">control</span> silicone or hydrophobic PLGA tubes, as investigated by immunohistochemical observation (by fluorescent microscopy with anti-neurofilament staining), histological observations (by light microscopy with toluidine blue staining and transmission electron microscopy), and electrophysiological evaluation (by compound muscle action potential measurement). This is probably owing to the effective permeation of nutrients and prevention of fibrous scar tissue invasion as well as the good mechanical strength of the tube to maintain a stable support structure for the nerve regeneration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26680310','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26680310"><span>The Society of Thoracic Surgeons Clinical Practice Guidelines on Arterial <span class="hlt">Conduits</span> for Coronary Artery Bypass Grafting.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Aldea, Gabriel S; Bakaeen, Faisal G; Pal, Jay; Fremes, Stephen; Head, Stuart J; Sabik, Joseph; Rosengart, Todd; Kappetein, A Pieter; Thourani, Vinod H; Firestone, Scott; Mitchell, John D</p> <p>2016-02-01</p> <p>Internal thoracic arteries (ITAs) should be used to bypass the left anterior descending (LAD) artery when bypass of the LAD is indicated (class of recommendation [COR] I, level of evidence [LOE] B). As an adjunct to left internal thoracic artery (LITA), a second arterial graft (right ITA or radial artery [RA]) should be considered in appropriate patients (COR IIa, LOE B). Use of bilateral ITAs (BITAs) should be considered in patients who do not have an excessive risk of sternal complications (COR IIa, LOE B). To reduce the risk of sternal infection with BITA, skeletonized grafts should be considered (COR IIa, LOE B), smoking cessation is recommended (COR I, LOE C), glycemic <span class="hlt">control</span> should be considered (COR IIa, LOE B), and enhanced sternal stabilization may be considered (COR IIb, LOE C). As an adjunct to LITA to LAD (or in patients with inadequate LITA grafts), use of a RA graft is reasonable when grafting coronary targets with severe stenoses (COR IIa, LOE: B). When RA grafts are used, it is reasonable to use pharmacologic agents to reduce acute intraoperative and perioperative spasm (COR IIa, LOE C). The right gastroepiploic artery may be considered in patients with poor <span class="hlt">conduit</span> options or as an adjunct to more complete arterial revascularization (COR IIb, LOE B). Use of arterial grafts (specific targets, number, and type) should be a part of the discussion of the heart team in determining the optimal approach for each patient (COR I, LOE C).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1513283G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1513283G"><span>Trees are important <span class="hlt">conduits</span> for emission of methane from temperate and tropical wetlands</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gauci, Vincent; Pangala, Sunitha; Gowing, David; Hornibrook, Edward</p> <p>2013-04-01</p> <p>Methane produced in wetland soil generally is thought to be emitted to the atmosphere primarily via diffusion through pore water, release of gas bubbles (i.e., ebullition), and gas phase diffusion through the aerenchyma of herbaceous plants. The role of trees as a <span class="hlt">conduit</span> for methane export from soil to the atmosphere has received limited attention despite evidence from mesocosm experiments showing that seedlings and saplings of wetland trees have a significant capacity to transport soil-produced gases. Notably ~60% of global wetlands are forested. We present in situ measurements of methane flux from a temperate carr (swamp) composed of alder (Alnus glutinosa) and birch (Betula pubescens) situated in the United Kingdom and a tropical forested peat swamp located in Borneo. The in situ data are complemented by a mesocosm experiment in which methane emissions were measured from alder saplings subjected to two water-regime treatments. In both the in situ and mesocosm studies, emissions from trees are compared to methane flux from the ground surface, the latter occurring via pore water diffusion, ebullition or the aerenchyma of herbaceous plants. We show that tree stem emissions are <span class="hlt">controlled</span> by a number of factors including tree species, soil pore-water concentration and stem lenticel density. Our results demonstrate that the omission of tree-mediated methane fluxes from measurement campaigns conducted in forested wetland can significantly underestimate total ecosystem flux of methane.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/871364','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/871364"><span>Device and method for measuring multi-phase fluid flow in a <span class="hlt">conduit</span> having an abrupt gradual bend</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Ortiz, Marcos German</p> <p>1998-01-01</p> <p>A system for measuring fluid flow in a <span class="hlt">conduit</span> having an abrupt bend. The system includes pressure transducers, one disposed in the <span class="hlt">conduit</span> at the inside of the bend and one or more disposed in the <span class="hlt">conduit</span> at the outside of the bend but spaced a distance therefrom. The pressure transducers measure the pressure of fluid in the <span class="hlt">conduit</span> at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the <span class="hlt">conduit</span>. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the <span class="hlt">conduit</span> elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/570469','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/570469"><span>Device and method for measuring multi-phase fluid flow in a <span class="hlt">conduit</span> having an abrupt gradual bend</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Ortiz, M.G.</p> <p>1998-02-10</p> <p>A system is described for measuring fluid flow in a <span class="hlt">conduit</span> having an abrupt bend. The system includes pressure transducers, one disposed in the <span class="hlt">conduit</span> at the inside of the bend and one or more disposed in the <span class="hlt">conduit</span> at the outside of the bend but spaced a distance therefrom. The pressure transducers measure the pressure of fluid in the <span class="hlt">conduit</span> at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the <span class="hlt">conduit</span>. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the <span class="hlt">conduit</span> elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow. 1 fig.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23229291','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23229291"><span>Percutaneous balloon dilation of Carpentier-Edwards porcine-valved right ventricle-to-pulmonary artery <span class="hlt">conduits</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hall, Amanda C; Miga, Daniel E; Leonard, Glenn T; Wang, Hongyue; Kavey, Rae-Ellen; Alfieris, George M</p> <p>2013-04-01</p> <p>Right ventricular outflow tract (RVOT) <span class="hlt">conduit</span> stenosis remains a significant problem for patients with right ventricle-to-pulmonary artery (RV-to-PA) <span class="hlt">conduits</span> placed as palliation for congenital heart disease. Previous reports on balloon dilation of RVOT <span class="hlt">conduits</span> all describe small series with varying levels of success during limited follow-up evaluation. This study reviewed all patients with RV-to-PA <span class="hlt">conduits</span> who underwent percutaneous balloon dilation for <span class="hlt">conduit</span> stenosis at the authors' institution from 2000 to 2011. Patients with Carpentier-Edwards (CE) model 4300 porcine-valved <span class="hlt">conduits</span> (Edwards Lifesciences Corp., Irvine, CA) (n = 19) were compared with patients who had all other types of <span class="hlt">conduits</span> (n = 19). Successful balloon angioplasty was defined as a 20 % decrease in the RV-to-PA gradient, a 20 % decrease in the ratio of the RV systolic-to-aortic systolic pressure, or both. Balloon dilation was successful for 57.9 % of the patients with CE <span class="hlt">conduits</span> and for 31.6 % of patients with other types of <span class="hlt">conduits</span> (p = 0.10, Chi square test). Logistic regression analysis showed that balloon dilation was significantly more likely to be successful with CE valves than with other types (odds ratio [OR], 6.59; 95 % confidence interval [CI], 1.22-35.49). In a continuous series of patients with stenotic RV-to-PA <span class="hlt">conduits</span>, the CE porcine-valved <span class="hlt">conduit</span> was more amenable to percutaneous balloon dilation than other types of RV-to-PA <span class="hlt">conduits</span> at the midterm follow-up evaluation. This has important ramifications in terms of valve selection for patients with congenital heart disease who will require surgical reintervention for RVOT stenosis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28443569','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28443569"><span>Can a Small Intestine Segment Be an Alternative Biological <span class="hlt">Conduit</span> for Peripheral Nerve Regeneration?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Arda, Mehmet S; Koçman, Emre A; Özkara, Emre; Söztutar, Erdem; Özatik, Orhan; Köse, Aydan; Çetin, Cengiz</p> <p>2017-05-05</p> <p>Autologous nerve grafts are used to bridge peripheral nerve defects. Limited sources and donor site morbidity are the major problems with peripheral nerve grafts. Although various types of autologous grafts such as arteries, veins and muscles have been recommended, an ideal <span class="hlt">conduit</span> has not yet been described. To investigate the effectiveness of a small intestinal <span class="hlt">conduit</span> for peripheral nerve defects. Animal experimentation. Twenty-one rats were divided into three groups (n=7). Following anaesthesia, sciatic nerve exploration was performed in the Sham group. The 10 mm nerve gap was bridged with a 15 mm ileal segment in the small intestinal <span class="hlt">conduit</span> group and the defect was replaced with orthotopic nerve in autologous nerve graft group. The functional recovery was tested monthly by walking-track analysis and the sciatic functional index. Histological evaluation was performed on the 12th week. Sciatic functional index tests are better in autologous nerve graft group (-55.09±6.35); however, during follow-up, progress in sciatic functional index was demonstrated, along with axonal regeneration and innervation of target muscles in the small intestinal <span class="hlt">conduit</span> group (-76.36±12.08) (p<0.05). In histologic sections, distinctive sciatic nerve regeneration was examined in the small intestinal <span class="hlt">conduit</span> group. The expression of S-100 and neurofilament was observed in small intestinal <span class="hlt">conduit</span> group but was less organised than in the autologous nerve graft group. Although the counted number (7459.79±1833.50 vs. 4226.51±1063.06 mm2), measured diameter [2.19 (2.15-2.88) vs. 1.74 (1.50-2.09) µm] and myelin sheath thickness [1.18 (1.09-1.44) vs. 0.66 (0.40-1.07) µm] of axons is significantly high in the middle sections of autologous nerve graft compared to the small intestinal <span class="hlt">conduit</span> group, respectively (p<0.05), the peripheral nerve regeneration was also observed in the small intestinal <span class="hlt">conduit</span> group. Small intestinal <span class="hlt">conduit</span> should not be considered as an alternative to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27345506','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27345506"><span>Alternative <span class="hlt">conduit</span> for infrageniculate bypass in patients with critical limb ischemia.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Moreira, Carla C; Leung, Alexander D; Farber, Alik; Rybin, Denis; Doros, Gheorghe; Siracuse, Jeffrey J; Kalish, Jeffrey; Eslami, Mohammad H</p> <p>2016-07-01</p> <p>Autologous great saphenous vein (GSV) has always been considered the gold standard <span class="hlt">conduit</span> for infrainguinal revascularization. When GSV is inadequate or unavailable, alternative <span class="hlt">conduits</span> have been used. In this study, we compared modern outcomes of different <span class="hlt">conduit</span> types used in lower extremity bypass (LEB) for patients with critical limb ischemia (CLI). The Vascular Study Group of New England database (2003-2014) was queried for patients who underwent infrageniculate bypass originating from the femoral arteries. <span class="hlt">Conduit</span> types were categorized as single-segment GSV, alternative autologous <span class="hlt">conduit</span> (AAC), and nonautologous <span class="hlt">conduit</span> (NAC). Primary outcomes were 1-year freedom from major adverse limb event (MALE), MALE-free survival, and primary graft patency. Multivariable Cox regression was used to adjust for demographics and comorbidities. LEB was performed in 2148 patients, of which 1125 were to below-knee popliteal (BK-Pop) and 1023 to infrapopliteal artery (IPA) targets. The baseline characteristics differed among the <span class="hlt">conduit</span> groups: Patients in the GSV group were younger and had fewer comorbidities than in the AAC groups. Patients undergoing BK-Pop bypass with NAC had higher rates of postoperative myocardial infarction (7.1%) and postoperative (5.8%) and 1-year death (40.8%) than in those with GSV (3.1%, 2%, and 31.7%, respectively) and AAC (0%, 0%, and 25%, respectively). In multivariable analysis, <span class="hlt">conduit</span> type did not make a difference in 1-year MALE, MALE-free survival, or primary graft patency for BK-Pop bypasses. For IPA bypasses, NAC use was associated with higher rates of postoperative (6.4%) and in-hospital death (4.5%) compared with GSV (2.5% and 1.4%, respectively) and AAC (2.9% and 1.9%, respectively). In adjusted analysis, NAC was associated with higher risk of MALE (hazard ratio [HR], 1.50; 95% confidence interval [CI], 1.03-2.20; P = .036) and primary patency loss (HR, 1.3; 95% CI, 0.91-1.89), and lower MALE-free survival (HR, 1.47; 95% CI, 1</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014Nanot..25p5102Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014Nanot..25p5102Y"><span>A novel electrospun nerve <span class="hlt">conduit</span> enhanced by carbon nanotubes for peripheral nerve regeneration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, Wenwen; Jiang, Xinquan; Cai, Ming; Zhao, Wen; Ye, Dongxia; Zhou, Yong; Zhu, Chao; Zhang, Xiuli; Lu, Xiaofeng; Zhang, Zhiyuan</p> <p>2014-04-01</p> <p>For artificial nerve <span class="hlt">conduits</span>, great improvements have been achieved in mimicking the structures and components of autologous nerves. However, there are still some problems in <span class="hlt">conduit</span> construction, especially in terms of mechanical properties, biomimetic surface tomography, electrical conductivity and sustained release of neurotrophic factors or cells. In this study, we designed and fabricated a novel electrospun nerve <span class="hlt">conduit</span> enhanced by multi-walled carbon nanotubes (MWNTs) on the basis of a collagen/poly(ɛ-caprolactone) (collagen/PCL) fibrous scaffold. Our aim was to provide further knowledge about the mechanical effects and efficacy of MWNTs on nerve <span class="hlt">conduits</span> as well as the biocompatibility and toxicology of MWNTs when applied in vivo. The results showed that as one component, carboxyl MWNTs could greatly alter the composite scaffold’s hydrophilicity, mechanical properties and degradability. The electrospun fibers enhanced by MWNTs could support Schwann cell adhesion and elongation as a substrate in vitro. In vivo animal studies demonstrated that the MWNT-enhanced collagen/PCL <span class="hlt">conduit</span> could effectively promote nerve regeneration of sciatic nerve defect in rats and prevent muscle atrophy without invoking body rejection or serious chronic inflammation. All of these results showed that this MWNT-enhanced scaffold possesses good biocompatibility and MWNTs might be excellent candidates as engineered nanocarriers for further neurotrophic factor delivery research.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23376237','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23376237"><span>New nerve regeneration strategy combining laminin-coated chitosan <span class="hlt">conduits</span> and stem cell therapy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hsu, Sung-Hao; Kuo, Wen-Chun; Chen, Yu-Tzu; Yen, Chen-Tung; Chen, Ying-Fang; Chen, Ko-Shao; Huang, Wen-Cheng; Cheng, Henrich</p> <p>2013-05-01</p> <p>Nerve regeneration remains a difficult challenge due to the lack of safe and efficient matrix support. We designed a laminin (LN)-modified chitosan multi-walled nerve <span class="hlt">conduit</span> combined with bone marrow stem cell (BMSC) grating to bridge a 10 mm long gap in the sciatic nerve of Sprague-Dawley rats. The repair outcome was monitored during 16 weeks after surgery. Successful grafting of LN onto the chitosan film, confirmed by immunolocalization, significantly improved cell adhesion. In vivo study showed that newly formed nerve cells covered the interior of the <span class="hlt">conduit</span> to connect the nerve gap successfully in all groups. The rats implanted with the <span class="hlt">conduit</span> combined with BMSCs showed the best results, in terms of nerve regrowth, muscle mass of gastrocnemius, function recovery and tract tracing. Neuroanatomical horseradish peroxidase tracer analysis of motor neurons in the lumbar spinal cord indicated that the amount and signal intensity were significantly improved. Furthermore, BMSCs suppressed neuronal cell death and promoted regeneration by suppressing the inflammatory and fibrotic response induced by chitosan after long-term implantation. In summary, this study suggests that LN-modified chitosan multi-walled nerve <span class="hlt">conduit</span> combined with BMSCs is an efficient and safe <span class="hlt">conduit</span> matrix for nerve regeneration. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28740120','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28740120"><span>Uncovering Offshore Financial Centers: <span class="hlt">Conduits</span> and Sinks in the Global Corporate Ownership Network.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Garcia-Bernardo, Javier; Fichtner, Jan; Takes, Frank W; Heemskerk, Eelke M</p> <p>2017-07-24</p> <p>Multinational corporations use highly complex structures of parents and subsidiaries to organize their operations and ownership. Offshore Financial Centers (OFCs) facilitate these structures through low taxation and lenient regulation, but are increasingly under scrutiny, for instance for enabling tax avoidance. Therefore, the identification of OFC jurisdictions has become a politicized and contested issue. We introduce a novel data-driven approach for identifying OFCs based on the global corporate ownership network, in which over 98 million firms (nodes) are connected through 71 million ownership relations. This granular firm-level network data uniquely allows identifying both sink-OFCs and <span class="hlt">conduit</span>-OFCs. Sink-OFCs attract and retain foreign capital while <span class="hlt">conduit</span>-OFCs are attractive intermediate destinations in the routing of international investments and enable the transfer of capital without taxation. We identify 24 sink-OFCs. In addition, a small set of five countries - the Netherlands, the United Kingdom, Ireland, Singapore and Switzerland - canalize the majority of corporate offshore investment as <span class="hlt">conduit</span>-OFCs. Each <span class="hlt">conduit</span> jurisdiction is specialized in a geographical area and there is significant specialization based on industrial sectors. Against the idea of OFCs as exotic small islands that cannot be regulated, we show that many sink and <span class="hlt">conduit</span>-OFCs are highly developed countries.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19115095','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19115095"><span>Evaluation of a multi-layer microbraided polylactic acid fiber-reinforced <span class="hlt">conduit</span> for peripheral nerve regeneration.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lu, Ming-Chin; Huang, Yen-Ting; Lin, Jia-Horng; Yao, Chun-Hsu; Lou, Ching-Wen; Tsai, Chin-Chuan; Chen, Yueh-Sheng</p> <p>2009-05-01</p> <p>We evaluated peripheral nerve regeneration using a biodegradable multi-layer microbraided polylactic acid (PLA) fiber-reinforced <span class="hlt">conduit</span>. Biodegradability of the PLA <span class="hlt">conduit</span> and its effectiveness as a guidance channel were examined as it was used to repair a 10 mm gap in the rat sciatic nerve. As a result, tube fragmentation was not obvious and successful regeneration through the gap occurred in all the <span class="hlt">conduits</span> at 8 weeks after operation. These results indicate the superiority of the PLA materials and suggest that the multi-layer microbraided PLA fiber-reinforced <span class="hlt">conduits</span> provide a promising tool for neuro-regeneration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70048750','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70048750"><span>Hawaiian fissure fountains: Quantifying vent and shallow <span class="hlt">conduit</span> geometry, episode 1 of the 1969-1974 Mauna Ulu eruption: Chapter 17</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Parcheta, Carolyn; Fagents, Sarah; Swanson, Donald A.; Houghton, Bruce; Ericksen, Todd; Carey, Rebecca; Cayol, Valérie; Poland, Michael P.; Weis, Dominique</p> <p>2015-01-01</p> <p>Geometries of shallow magmatic pathways feeding volcanic eruptions are poorly constrained, yet many key interpretations about eruption dynamics depend on knowledge of these geometries. Direct quantification is difficult because vents typically become blocked with lava at the end of eruptions. Indirect geophysical techniques have shed light on some volcanic <span class="hlt">conduit</span> geometries, but the scales are too coarse to resolve narrow fissures (widths typically 1 m). Kīlauea's Mauna Ulu eruption, which started with <50 m high Hawaiian fountains along a 4.5 km fissure on 24 May 1969, provides a unique opportunity to measure the detailed geometry of a shallow magmatic pathway, as the western vents remain unobstructed to depths >30 m. Direct measurements at the ground surface were augmented by tripod-mounted lidar measurements to quantify the shallow <span class="hlt">conduit</span> geometry for three vents at a resolution <4 cm. We define the form of the fissure in terms of aspect ratio, flaring ratio, irregularity, sinuosity, and segmentation and discuss the factors influencing these parameters. In the past, simplified first-order fissure geometries have been used in computational modeling. Our data can provide more accurate <span class="hlt">conduit</span> shapes for better understanding of shallow fissure fluid dynamics and how it <span class="hlt">controls</span> eruptive behavior, especially if incorporated into computer models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4591245','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4591245"><span>A Modular, Plasmin-Sensitive, Clickable Poly(ethylene glycol)-Heparin-Laminin Microsphere System for Establishing Growth Factor Gradients in Nerve Guidance <span class="hlt">Conduits</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Roam, Jacob L.; Yan, Ying; Nguyen, Peter K.; Kinstlinger, Ian S.; Leuchter, Michael K; Hunter, Daniel A.; Wood, Matthew D.; Elbert, Donald L.</p> <p>2015-01-01</p> <p>Peripheral nerve regeneration is a complex problem that, despite many advancements and innovations, still has sub-optimal outcomes. Compared to biologically derived acelluar nerve grafts and autografts, completely synthetic nerve guidance <span class="hlt">conduits</span> (NGC), which allow for precise engineering of their properties, are promising but still far from optimal. We have developed an almost entirely synthetic NGC that allows <span class="hlt">control</span> of soluble growth factor delivery kinetics, cell-initiated degradability and cell attachment. We have focused on the spatial patterning of glial-cell derived human neurotrophic factor (GDNF), which promotes motor axon extension. The base scaffolds consisted of heparin-containing poly(ethylene glycol) (PEG) microspheres. The modular microsphere format greatly simplifies the formation of concentration gradients of reversibly bound GDNF. To facilitate axon extension, we engineered the microspheres with tunable plasmin degradability. ‘Click’ cross-linking chemistries were also added to allow scaffold formation without risk of covalently coupling the growth factor to the scaffold. Cell adhesion was promoted by covalently bound laminin. GDNF that was released from these microspheres was confirmed to retain its activity. Graded scaffolds were formed inside silicone <span class="hlt">conduits</span> using 3D-printed holders. The fully formed NGC’s contained plasmin-degradable PEG/heparin scaffolds that developed linear gradients in reversibly bound GDNF. The NGC’s were implanted into rats with severed sciatic nerves to confirm in vivo degradability and lack of a major foreign body response. The NGC’s also promoted robust axonal regeneration into the <span class="hlt">conduit</span>. PMID:26352518</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/227035','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/227035"><span>Extension of in-situ stress test analysis to rapid hole evacuation at Yucca Mountain due to a network of open <span class="hlt">conduits</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Davies, J.B.</p> <p>1994-01-01</p> <p>Yucca Mountain is underlain by tuffaceous rocks that are highly fractured and jointed. During drilling of bore-holes at Yucca Mountain there were numerous occurrences of lost circulation when whole mud was taken by the formation. This evidence suggests that parts of Yucca Mountain are <span class="hlt">controlled</span> hydrologicaly by a network of open <span class="hlt">conduits</span> along the existing joints and fractures. Also at Yucca Mountain, stress tests have been performed in-situ by charging a small section along the boreholes with an excess pressure head of water. For many of these tests, the initial drop in water head was so rapid that within seconds up to hundreds of meters of fall had occurred. The opening of fractures as the excess head increases has previously been proposed as an important factor in explaining the shape of the stress test curves at lower pressures. We propose that such induced hydraulic fractures, under increasing water heads, can grow to a length sufficient to intersect the existing network of open joints and fractures. We extend our previous model to incorporate flow out along these open <span class="hlt">conduits</span> and examine the initial rapid drop in terms of these extended models. We show that this rapid evacuation model fits the observed data from many slug tests in wells in the vicinity of Yucca Mountain. This result is confirmation of the drilling evidence that a network of open <span class="hlt">conduits</span> exists at various depths below the water table and over a large geographic region around Yucca Mountain.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1611950S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1611950S"><span>The interior of a volcanic summit: TerraSAR-X interferometry reveals complex <span class="hlt">conduit</span> system at Volcán de Colima, Mexico</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Salzer, Jacqueline T.; Nikkhoo, Mehdi; Walter, Thomas R.; Reyes-Dávila, Gabriel; Bretón, Mauricio; Arambula-Mendoza, Raul</p> <p>2014-05-01</p> <p>The dimensions and shape of the volcanic <span class="hlt">conduit</span> is one of the main parameters <span class="hlt">controlling</span> the dynamics and style volcanic eruptions and their precursors, but also one of the main unknowns. Different types of pre-eruptive signals originate from this region, such as changes in the gas composition, earthquakes, tremors and long periodic seismicity, as well as deformation on different scales, all of which strictly depend on the source geometry. However, vulnerability of near-summit stations during explosive eruptions leads to a sparse spatial resolution and hence poor a knowledge of the shallow source process and its parameters. Such incomplete observations also increase the difficulty of identifying episodes of unrest that will lead to eruption. At Volcán de Colima, Mexico, the plumbing of the shallow <span class="hlt">conduit</span> system caused detectable and characteristic volcano deformation during the days prior to the renewal of the volcanic activity in 2013, which was initiated by an explosion. Here we present a model of the shallow <span class="hlt">conduit</span> system at Colima, based on pre-explosive summit deformation detected in high resolution satellite radar and camera observations. The radar data are interferometrically processed to provide displacement maps up to 7 hours before the explosion, and are synthetically well reproduced using a boundary element method. This allows constraining a complex, possibly curved ascent path, with at least two hydraulically connected pressurized regions at shallow levels beneath the dome. The locations of the sources coincide with the later path of magma ascent. Our results highlight the geometrical complexity of the shallow <span class="hlt">conduit</span> system at Colima, which can condionally become detectable when being plumbed prior to explosive eruptions. The small temporal and spatial extent of the deformation signal may explain why many volcano eruptions occur without precursory deformation activity.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMGP13C..07F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMGP13C..07F"><span>Inverse Dipolar Magnetic Anomaly Over the Volcanic Cone Linked to Reverse Polarity Magnetizations in Lavas and Tuffs - Implications for the <span class="hlt">Conduit</span> System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fucugauchi, J. U.; Perez-Cruz, L. L.; Trigo-Huesca, A.</p> <p>2012-12-01</p> <p>A combined magnetics and paleomagnetic study of Toluquilla monogenetic volcano and associated lavas and tuffs from Valsequillo basin in Central Mexico provides evidence on a magnetic link between lavas, ash tuffs and the underground volcanic <span class="hlt">conduit</span> system. Paleomagnetic analyses show that lavas and ash tuffs carry reverse polarity magnetizations, which correlate with the inversely polarized dipolar magnetic anomaly over the volcano. The magnetizations in the lava and tuff show similar southward declinations and upward inclinations, supporting petrological inferences that the tuff was emplaced while still hot and indicating a temporal correlation for lava and tuff emplacement. <span class="hlt">Conduit</span> geometry is one of the important <span class="hlt">controlling</span> factors in eruptive dynamics of basaltic volcanoes. However volcanic <span class="hlt">conduits</span> are often not, or only partly, exposed. Modeling of the dipolar anomaly gives a reverse polarity source magnetization associated with a vertical prismatic body with southward declination and upward inclination, which correlates with the reverse polarity magnetizations in the lava and tuff. The study documents a direct correlation of the paleomagnetic records with the underground magmatic <span class="hlt">conduit</span> system of the monogenetic volcano. Time scale for cooling of the volcanic plumbing system involves a longer period than the one for the tuff and lava, suggesting that magnetization for the source of dipolar anomaly may represent a long time average as compared to the spot readings in the lava and tuff. The reverse polarity magnetizations in lava and tuff and in the underground source body for the magnetic anomaly are interpreted in terms of eruptive activity of Toluquilla volcano at about 1.3 Ma during the Matuyama reverse polarity C1r.2r chron.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.V21B2722G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.V21B2722G"><span>Shallow <span class="hlt">conduit</span> processes of the 1991 Hekla eruption, Iceland</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gudnason, J.; Thordarson, T.; Houghton, B. F.</p> <p>2013-12-01</p> <p>On January 17, 1991 at 17:00 hrs, the 17th eruption of Hekla since 1104AD began. Lasting for almost two months, it produced 0.02 km3 of icelandite tephra and ~0.15km3 of icelandite lava. This eruption was the third of four eruptions since 1980 with a recurrence period of approximately 10 years, as opposed to a recurrence interval of c. 55 years for the eruptions in the period 1104AD to 1947AD. [1] The last four Hekla eruptions are typified by a 0.5-2 hour-long initial phase of subplinian intensity and discharge ranging from 2900-6700 m3/s [2]. In all 4 events the inital phase was followed by a sustained and relatively low-discharge(<20 m3/s) effusive phase, which in the case of Hekla 1991 lasted until the 11th March 1991 [1]. The initial phase of the 1991 event lasted for ~50 minutes and sustained an eruption plume that rose to 11.5 km in about 10 minutes [1]. The plume was dispersed to the NNE at velocities of 60-70 km/hr producing a well-sorted tephra fall covering >20,000 km2. Here we examine the first phase of the Hekla 1991 eruption with focus on vesiculation and fragmentation processes in the shallow <span class="hlt">conduit</span> and ash production. Samples of the tephra fall were collected on snow immediately after the initial phase at multiple sites providing a representative spatial coverage within the 0.1mm isopach [3]. This set was augmented by samples collected in 2012 to provide tighter coverage of near vent region. Grain size of all samples has been measured down to 1 micron. Density measurements have been conducted on 4 near-vent pumice samples (100 clasts each) and the pumice vesicle size distribution has been determined in a selected subset of clasts. The reconstructed whole deposit grain size distribution exhibits a unimodal, log-normal distribution peaking at -3 phi, typical of dry, magmatic fragmentation. Pumice densities range from 520-880 kg/m3 and exhibit a tight unimodal and log-normal distribution indicating a mean vesicularity of 77% to 79% for the magma</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19916548','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19916548"><span>Impact of <span class="hlt">conduit</span> geometry on the performance of typical particulate microchip packings.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jung, Stephanie; Höltzel, Alexandra; Ehlert, Steffen; Mora, Jose-Angel; Kraiczek, Karsten; Dittmann, Monika; Rozing, Gerard P; Tallarek, Ulrich</p> <p>2009-12-15</p> <p>This work investigates the impact of <span class="hlt">conduit</span> geometry on the chromatographic performance of typical particulate microchip packings. For this purpose, high-performance liquid chromatography (HPLC)/UV-microchips with separation channels of quadratic, trapezoidal, or Gaussian cross section were fabricated by direct laser ablation and lamination of multiple polyimide layers and then slurry-packed with either 3 or 5 microm spherical porous C8-silica particles under optimized packing conditions. Experimentally determined plate height curves for the empty microchannels are compared with dispersion coefficients from theoretical calculations. Packing densities and plate height curves for the various microchip packings are presented and conclusively explained. The 3 microm packings display a high packing density irrespective of their <span class="hlt">conduit</span> geometries, and their performance reflects the dispersion behavior of the empty channels. Dispersion in 5 microm packings correlates with the achieved packing densities, which are limited by the number and accessibility of corners in a given <span class="hlt">conduit</span> shape.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013GeoRL..40.6038B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013GeoRL..40.6038B"><span>Magma fracture and hybrid earthquakes in the <span class="hlt">conduit</span> of Augustine Volcano</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Buurman, Helena; West, Michael E.</p> <p>2013-12-01</p> <p>exploit subtle but systematic shifts in seismic waveforms to examine a 2 h cluster of repeating hybrid volcanic earthquakes preceding the first magmatic explosions at Augustine Volcano in January 2006. We extract differential P wave traveltimes of <0.01 s to determine that the source locations migrated downward by approximately 35 m. Waveform characteristics, GPS observations, and visual reports of lava effusion at the summit suggest that the earthquakes were sourced by fracturing magma in the upper <span class="hlt">conduit</span>. As the lava cooled and degassed at the surface, the conditions in the upper <span class="hlt">conduit</span> changed causing the zone in which magma fracture could occur to move downward through the magma column. These changes may also have been the first indicators that the <span class="hlt">conduit</span> was becoming choked, causing a buildup in pressure that resulted in the large magmatic explosions that followed 36 h later.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19076529','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19076529"><span>Capacitive effect of cavitation in xylem <span class="hlt">conduits</span>: results from a dynamic model.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hölttä, Teemu; Cochard, Herve; Nikinmaa, Eero; Mencuccini, Maurizio</p> <p>2009-01-01</p> <p>Embolisms decrease plant hydraulic conductance and therefore reduce the ability of the xylem to transport water to leaves provided that embolized <span class="hlt">conduits</span> are not refilled. However, as a xylem <span class="hlt">conduit</span> is filled with gas during cavitation, water is freed to the transpiration stream and this transiently increases xylem water potential. This capacitive effect of embolism formation on plant function has not been explicitly quantified in the past. A dynamic model is presented that models xylem water potential, xylem sap flow and cavitation, taking into account both the decreasing hydraulic conductance and the water release effect of xylem embolism. The significance of the capacitive effect increases in relation to the decreasing hydraulic conductance effect when transpiration rate is low in relation to the total amount of water in xylem <span class="hlt">conduits</span>. This ratio is typically large in large trees and during drought.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4697439','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4697439"><span>Physical nanoscale <span class="hlt">conduit</span>-mediated communication between tumour cells and the endothelium modulates endothelial phenotype</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Connor, Yamicia; Tekleab, Sarah; Nandakumar, Shyama; Walls, Cherelle; Tekleab, Yonatan; Husain, Amjad; Gadish, Or; Sabbisetti, Venkata; Kaushik, Shelly; Sehrawat, Seema; Kulkarni, Ashish; Dvorak, Harold; Zetter, Bruce; R. Edelman, Elazer; Sengupta, Shiladitya</p> <p>2015-01-01</p> <p>Metastasis is a major cause of mortality and remains a hurdle in the search for a cure for cancer. Not much is known about metastatic cancer cells and endothelial cross-talk, which occurs at multiple stages during metastasis. Here we report a dynamic regulation of the endothelium by cancer cells through the formation of nanoscale intercellular membrane bridges, which act as physical <span class="hlt">conduits</span> for transfer of microRNAs. The communication between the tumour cell and the endothelium upregulates markers associated with pathological endothelium, which is reversed by pharmacological inhibition of these nanoscale <span class="hlt">conduits</span>. These results lead us to define the notion of ‘metastatic hijack': cancer cell-induced transformation of healthy endothelium into pathological endothelium via horizontal communication through the nanoscale <span class="hlt">conduits</span>. Pharmacological perturbation of these nanoscale membrane bridges decreases metastatic foci in vivo. Targeting these nanoscale membrane bridges may potentially emerge as a new therapeutic opportunity in the management of metastatic cancer. PMID:26669454</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19291791','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19291791"><span>Processed allografts and type I collagen <span class="hlt">conduits</span> for repair of peripheral nerve gaps.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Whitlock, Elizabeth L; Tuffaha, Sami H; Luciano, Janina P; Yan, Ying; Hunter, Daniel A; Magill, Christina K; Moore, Amy M; Tong, Alice Y; Mackinnon, Susan E; Borschel, Gregory H</p> <p>2009-06-01</p> <p>Autografting is the gold standard in the repair of peripheral nerve injuries that are not amenable to end-to-end coaptation. However, because autografts result in donor-site defects and are a limited resource, an effective substitute would be valuable. In a rat model, we compared isografts with Integra NeuraGen (NG) nerve guides, which are a commercially available type I collagen <span class="hlt">conduit</span>, with processed rat allografts comparable to AxoGen's Avance human decellularized allograft product. In a 14-mm sciatic nerve gap model, isograft was superior to processed allograft, which was in turn superior to NG <span class="hlt">conduit</span> at 6 weeks postoperatively (P < 0.05 for number of myelinated fibers both at midgraft and distal to the graft). At 12 weeks, these differences were no longer apparent. In a 28-mm graft model, isografts again performed better than processed allografts at both 6 and 22 weeks; regeneration through the NG <span class="hlt">conduit</span> was often insufficient for analysis in this long graft model. Functional tests confirmed the superiority of isografts, although processed allografts permitted successful reinnervation of distal targets not seen in the NG <span class="hlt">conduit</span> groups. Processed allografts were inherently non-immunogenic and maintained some internal laminin structure. We conclude that, particularly in a long gap model, nerve graft alternatives fail to confer the regenerative advantages of an isograft. However, AxoGen processed allografts are superior to a currently available <span class="hlt">conduit</span>-style nerve guide, the Integra NeuraGen. They provide an alternative for reconstruction of short nerve gaps where a <span class="hlt">conduit</span> might otherwise be used.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5023924','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5023924"><span>Comparison of postoperative acute kidney injury between ileal <span class="hlt">conduit</span> and neobladder urinary diversions after radical cystectomy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Joung, Kyoung-Woon; Kong, Yu-Gyeong; Yoon, Syn-Hae; Kim, Yeon Ju; Hwang, Jai-Hyun; Hong, Bumsik; Kim, Young-Kug</p> <p>2016-01-01</p> <p>Abstract Ileal <span class="hlt">conduit</span> and neobladder urinary diversions are frequently performed after radical cystectomy. However, complications after radical cystectomy may be different according to the type of urinary diversion. Acute kidney injury (AKI) is a common complication after surgery and increases costs, morbidity, and mortality of hospitalized patients. This study was performed to compare the incidence of postoperative AKI between ileal <span class="hlt">conduit</span> and neobladder urinary diversions after radical cystectomy. All consecutive patients who underwent radical cystectomy in 2004 to 2014 in a single tertiary care center were identified. The patients were divided into the ileal <span class="hlt">conduit</span> and ileal neobladder groups. Preoperative variables, including demographics, cancer-related data and laboratory values, as well as intraoperative data and postoperative outcomes, including AKI, intensive care unit admission rate, and the duration of hospital stay, were evaluated between the groups. Postoperative AKI was defined according to the Kidney Disease: Improving Global Outcome criteria. Propensity score matching analysis was performed to reduce the influence of possible confounding variables and adjust for intergroup differences. After performing 1:1 propensity score matching, the ileal <span class="hlt">conduit</span> and ileal neobladder groups each included 101 patients. The overall incidence of AKI after radical cystectomy was 30.7% (62 out of 202) and the incidences did not significantly differ between the groups (27 [26.7%], ileal <span class="hlt">conduit</span> group vs 35 [34.7%], ileal neobladder group, P = 0.268). Intraoperative data, intensive care unit admission rate, and the duration of hospital stay were not significantly different between the groups. Postoperative AKI did not significantly differ between ileal <span class="hlt">conduit</span> and neobladder urinary diversions after radical cystectomy. This finding provides additional information useful for appropriate selection of the urinary diversion type in conjunction with radical cystectomy</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.V53A3063L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.V53A3063L"><span>VLP seismicity from resonant modes of acoustic-gravity waves in a <span class="hlt">conduit</span>-crack system filled with multiphase magma</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liang, C.; Prochnow, B. N.; OReilly, O. J.; Dunham, E. M.; Karlstrom, L.</p> <p>2016-12-01</p> <p>Oscillation of magma in volcanic <span class="hlt">conduits</span> connected to cracks (dikes and sills) has been suggested as an explanation for very long period (VLP) seismic signals recorded at active basaltic volcanoes such as. Kilauea, Hawaii, and Erebus, Antarctica. We investigate the VLP seismicity using a linearized model for waves in and associated eigenmodes of a coupled <span class="hlt">conduit</span>-crack system filled with multiphase magma, an extension of the Karlstrom and Dunham (2016) model for acoustic-gravity waves in volcanic <span class="hlt">conduits</span>. We find that the long period surface displacement (as recorded on broadband seismometers) is dominated by opening/closing of the crack rather than the deformation of the <span class="hlt">conduit</span> <span class="hlt">conduit</span> walls. While the fundamental eigenmode is sensitive to the fluid properties and the geometry of the magma plumbing system, a closer scrutiny of various resonant modes reveals that the surface displacement is often more sensitive to higher modes. Here we present a systematic analysis of various long period acoustic-gravity wave resonant modes of a coupled <span class="hlt">conduit</span>-crack system that the surface displacement is most sensitive to. We extend our previous work on a quasi-one-dimensional <span class="hlt">conduit</span> model with inviscid magma to a more general axisymmetric <span class="hlt">conduit</span> model that properly accounts for viscous boundary layers near the <span class="hlt">conduit</span> walls, based on the numerical method developed by Prochnow et al. (submitted to Computers and Fluids, 2016). The surface displacement is dominated by either the fundamental or higher eigenmodes, depending on magma properties and the geometry of <span class="hlt">conduit</span> and crack. An examination of the energetics of these modes reveals the complex interplay of different restoring forces (magma compressibility in the <span class="hlt">conduit</span>, gravity, and elasticity of the crack) driving the VLP oscillations. Both nonequilibrium bubble growth and resorption and viscosity contribute to the damping of VLP signals. Our models thus provide a means to infer properties of open-vent basaltic volcanoes</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26199615','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26199615"><span>Biological <span class="hlt">conduits</span> combining bone marrow mesenchymal stem cells and extracellular matrix to treat long-segment sciatic nerve defects.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Yang; Li, Zheng-Wei; Luo, Min; Li, Ya-Jun; Zhang, Ke-Qiang</p> <p>2015-06-01</p> <p>The transplantation of polylactic glycolic acid <span class="hlt">conduits</span> combining bone marrow mesenchymal stem cells and extracellular matrix gel for the repair of sciatic nerve injury is effective in some respects, but few data comparing the biomechanical factors related to the sciatic nerve are available. In the present study, rabbit models of 10-mm sciatic nerve defects were prepared. The rabbit models were repaired with autologous nerve, a polylactic glycolic acid <span class="hlt">conduit</span> + bone marrow mesenchymal stem cells, or a polylactic glycolic acid <span class="hlt">conduit</span> + bone marrow mesenchymal stem cells + extracellular matrix gel. After 24 weeks, mechanical testing was performed to determine the stress relaxation and creep parameters. Following sciatic nerve injury, the magnitudes of the stress decrease and strain increase at 7,200 seconds were largest in the polylactic glycolic acid <span class="hlt">conduit</span> + bone marrow mesenchymal stem cells + extracellular matrix gel group, followed by the polylactic glycolic acid <span class="hlt">conduit</span> + bone marrow mesenchymal stem cells group, and then the autologous nerve group. Hematoxylin-eosin staining demonstrated that compared with the polylactic glycolic acid <span class="hlt">conduit</span> + bone marrow mesenchymal stem cells group and the autologous nerve group, a more complete sciatic nerve regeneration was found, including good myelination, regularly arranged nerve fibers, and a completely degraded and resorbed <span class="hlt">conduit</span>, in the polylactic glycolic acid <span class="hlt">conduit</span> + bone marrow mesenchymal stem cells + extracellular matrix gel group. These results indicate that bridging 10-mm sciatic nerve defects with a polylactic glycolic acid <span class="hlt">conduit</span> + bone marrow mesenchymal stem cells + extracellular matrix gel construct increases the stress relaxation under a constant strain, reducing anastomotic tension. Large elongations under a constant physiological load can limit the anastomotic opening and shift, which is beneficial for the regeneration and functional reconstruction of sciatic nerve. Better regeneration was</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1228844','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1228844"><span>Pressure distribution along the AGS vacuum chambers with new types of pump out <span class="hlt">conduits</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nayak, S.; Mapes, M.; Smart, L.; Weiss, D.</p> <p>2015-10-28</p> <p>The AGS HEBT and ring vacuum system is monitored by the discharge current of the magnet ion pumps, which is proportional to the pressure at the inlet port of these ion pumps. The discharge current is measured and suitably calibrated to indicate the ion pump pressure. In order to calculate the vacuum chamber pressure from the ion pump pressure, a detailed analysis is essential to compute their difference in different scenarios. Such analysis has been carried out numerically in the past for the system with the older type of pump out <span class="hlt">conduits</span>, and similar analysis using FEM in ANSYS is presented in this paper with the newer type of pump out <span class="hlt">conduit</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1184132','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1184132"><span>Havery Mudd 2014-2015 Computer Science <span class="hlt">Conduit</span> Clinic Final Report</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Aspesi, G; Bai, J; Deese, R; Shin, L</p> <p>2015-05-12</p> <p><span class="hlt">Conduit</span>, a new open-source library developed at Lawrence Livermore National Laboratories, provides a C++ application programming interface (API) to describe and access scientific data. Conduit’s primary use is for inmemory data exchange in high performance computing (HPC) applications. Our team tested and improved <span class="hlt">Conduit</span> to make it more appealing to potential adopters in the HPC community. We extended Conduit’s capabilities by prototyping four libraries: one for parallel communication using MPI, one for I/O functionality, one for aggregating performance data, and one for data visualization.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3918631','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3918631"><span>A rare case of prosthetic endocarditis and dehiscence in a mechanical valved <span class="hlt">conduit</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kannan, Arun; Smith, Cristy; Subramanian, Sreekumar; Janardhanan, Rajesh</p> <p>2014-01-01</p> <p>A middle-aged adult patient with a history of aortic root replacement with a mechanical valved <span class="hlt">conduit</span> and remote chest trauma was referred to our institution with prosthetic endocarditis. Transoesophageal echocardiogram at our institution confirmed a near-complete dehiscence of the prosthetic aortic valve from the <span class="hlt">conduit</span>, with significant perivalvular flow forming a pseudoaneurysm. The patient underwent a high-risk re-operation, involving redo aortic root replacement with a homograft after extensive debridement of the infected tissue. The patient was discharged to an outside facility after an uncomplicated hospital course, and remains stable. PMID:24510692</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24510692','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24510692"><span>A rare case of prosthetic endocarditis and dehiscence in a mechanical valved <span class="hlt">conduit</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kannan, Arun; Smith, Cristy; Subramanian, Sreekumar; Janardhanan, Rajesh</p> <p>2014-02-07</p> <p>A middle-aged adult patient with a history of aortic root replacement with a mechanical valved <span class="hlt">conduit</span> and remote chest trauma was referred to our institution with prosthetic endocarditis. Transoesophageal echocardiogram at our institution confirmed a near-complete dehiscence of the prosthetic aortic valve from the <span class="hlt">conduit</span>, with significant perivalvular flow forming a pseudoaneurysm. The patient underwent a high-risk re-operation, involving redo aortic root replacement with a homograft after extensive debridement of the infected tissue. The patient was discharged to an outside facility after an uncomplicated hospital course, and remains stable.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6484649','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6484649"><span>Transient heat transfer from a cable in <span class="hlt">conduit</span> configuration in subcooled he I and he II</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chen, Z.; Van Sciver, S.W.</p> <p>1985-03-01</p> <p>Experimental investigations of liquid helium heat transfer from a model of a cable in <span class="hlt">conduit</span> conductor are reported. The model consists of a 19 element stainless steel tubing bundle contained within a rectangular cross section <span class="hlt">conduit</span>. The experiment involves resistively heating the bundle with a constant amplitude heat pulse, while recording the time variation of the temperature within the conductors and helium. Three test sections were studied each having a different spacing between the elements, delta. Results reported here are for bath temperatures 4.2, 2.5 and 1.8 K with applied pressure p = 100 kPa (1 atm).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.V23D4823D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.V23D4823D"><span>Wave Propagation in Axi-Symmetrical Magmatic <span class="hlt">Conduits</span> Due to an Internal Source</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>De Negri, R. S.; Sanchez-Sesma, F. J.; Arciniega-Ceballos, A.</p> <p>2014-12-01</p> <p>The classical Trefftz's method is implemented to simulate wave propagation in and around axi-symmetrical magmatic <span class="hlt">conduits</span>. In this fluid-solid system the fluid (magma) is confined by an elastic unbounded medium that represents the surrounding rock. Our aim is to associate wave behavior with mechanical and geometrical <span class="hlt">conduit</span> characteristics. The source is assumed to be at a point along the <span class="hlt">conduit</span> centered axis medium are constructed in both cases as linear combinations of particular solutions.Within the fluid such solutions are spherical standing waves that are smooth at the origins. In the elastic solid region the field is constructed with monopoles and dipoles for the P waves and spheroidal dipoles for SV waves. The particular solutions satisfy the elastodynamic equations that govern the wave motion at those media and are associated to origins (selected points) distributed along the <span class="hlt">conduit</span> axis. For the surrounding rock the solutions are sources that satisfy Sommerfeld's radiation condition. These sets of solutions are assumed to be complete. This conjecture is exact in 2D acoustic problems. The <span class="hlt">conduit</span> can be closed or open at the ends and the surrounding elastic domain is unbounded. In order to find the coefficients of Trefftz's wave expansions, boundary conditions at the fluid-solid interface (null shear and continuity of pressures and normal velocities) are satisfied in the least squares sense. The solution is obtained in the frequency domain and the source time function can be introduced using Fourier analysis.Regardless the low order of the formulation our results display a rich variety of behaviors. For a uniform infinite cylinder we reproduced the exact analytical solution. In addition, this approach allows identifying some important effects of the <span class="hlt">conduit</span> geometry, including changes of sections. Lateral and longitudinal resonances of irregular axi-symmetric <span class="hlt">conduits</span> are well resolved. The stiffness of the solid domain with respect to the fluid</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010CPL...498..307N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010CPL...498..307N"><span>Direct electron-transfer <span class="hlt">conduits</span> constructed at the interface between multicopper oxidase and nanocrystalline semiconductive Fe oxides</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nakamura, Ryuhei; Kamiya, Kazuhide; Hashimoto, Kazuhito</p> <p>2010-10-01</p> <p>Herein, the electron-transfer reactions occurring at the interface between bilirubin oxidase (BOD) and nanocrystalline hematite (α-Fe 2O 3) were characterized. Cyclic voltammograms indicated that BOD has an affinity for hematite surfaces and establishes a direct electron-transfer (DET) <span class="hlt">conduit</span> between the primary electron acceptor T1 site and the conduction band of α-Fe 2O 3. DET was also confirmed photo-electrochemically, as cathodic photocurrents were generated when a nanocomposite of BOD and α-Fe 2O 3 was illuminated under oxygenated conditions. A proline residue displayed a high-binding affinity for hematite surfaces and is therefore likely part of an orientation-<span class="hlt">controlled</span> motif which serves to locate BOD at the T1 site at a suitable distance for DET to α-Fe 2O 3.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title26-vol13/pdf/CFR-2010-title26-vol13-sec1-6081-7.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title26-vol13/pdf/CFR-2010-title26-vol13-sec1-6081-7.pdf"><span>26 CFR 1.6081-7 - Automatic extension of time to file Real Estate Mortgage Investment <span class="hlt">Conduit</span> (REMIC) income tax...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-04-01</p> <p>... 26 Internal Revenue 13 2010-04-01 2010-04-01 false Automatic extension of time to file Real Estate... Time for Filing Returns § 1.6081-7 Automatic extension of time to file Real Estate Mortgage Investment <span class="hlt">Conduit</span> (REMIC) income tax return. (a) In general. A Real Estate Mortgage Investment <span class="hlt">Conduit</span>...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1814738B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1814738B"><span>The evolution of periodic seismicity, waveform similarity, and <span class="hlt">conduit</span> processes during unrest episodes at Tungurahua volcano, Ecuador, in 2015</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bell, Andrew; Hernandez, Stephen; Gaunt, Elizabeth; Mothes, Patricia; Hidalgo, Silvana; Ruiz, Mario</p> <p>2016-04-01</p> <p> November with juvenile magma was quickly followed by a resumption of periodic low-frequency seismicity. The changes in the seismicity of Tungurahua in 2015 suggest a significant change in the magma-<span class="hlt">conduit</span> system. Elevated periodicity may indicate the presence of a slowly upward moving plug at a depth of 1-2km below the summit crater, likely associated with the unusually long repose period since the last major vulcanian episode in October 2014. Evolution in the periodicity and type of seismic signals within and between unrest episodes will be <span class="hlt">controlled</span> by a combination of the gas flux and permeability, and a balance between thermo-mechanical plug degradation and time-dependent healing processes. These factors are also likely to determine the nature of future eruptive activity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GGG....17.4179S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GGG....17.4179S"><span>Time scales of foam stability in shallow <span class="hlt">conduits</span>: Insights from analogue experiments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Spina, L.; Scheu, B.; Cimarelli, C.; Arciniega-Ceballos, A.; Dingwell, D. B.</p> <p>2016-10-01</p> <p>Volcanic systems can exhibit periodical trends in degassing activity, characterized by a wide range of time scales. Understanding the dynamics that <span class="hlt">control</span> such periodic behavior can provide a picture of the processes occurring in the feeding system. Toward this end, we analyzed the periodicity of outgassing in a series of decompression experiments performed on analogue material (argon-saturated silicone oil plus glass beads/fibers) scaled to serve as models of basaltic magma. To define the effects of liquid viscosity and crystal content on the time scale of outgassing, we investigated both: (1) pure liquid systems, at differing viscosities (100 and 1000 Pa s), and (2) particle-bearing suspensions (diluted and semidiluted). The results indicate that under dynamic conditions (e.g., decompressive bubble growth and fluid ascent within the <span class="hlt">conduit</span>), the periodicity of foam disruption may be up to several orders of magnitude less than estimates based on the analysis of static conditions. This difference in foam disruption time scale is inferred to result from the contribution of bubble shear and bubble growth to inter-bubble film thinning. The presence of particles in the semidiluted regime is further linked to shorter bubble bursting times, likely resulting from contributions of the presence of a solid network and coalescence processes to the relative increase in bubble breakup rates. Finally, it is argued that these experiments represent a good analogue of gas-piston activity (i.e., the periodical rise-and-fall of a basaltic lava lake surface), implying a dominant role for shallow foam accumulation as a source process for these phenomena.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/4054939','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/4054939"><span>Hydraulic balancing of a <span class="hlt">control</span> component within a nuclear reactor</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Marinos, D.; Ripfel, H.C.F.</p> <p>1975-10-14</p> <p>A reactor <span class="hlt">control</span> component includes an inner <span class="hlt">conduit</span>, for instance containing neutron absorber elements, adapted for longitudinal movement within an outer guide duct. A transverse partition partially encloses one end of the <span class="hlt">conduit</span> and meets a transverse wall within the guide duct when the <span class="hlt">conduit</span> is fully inserted into the reactor core. A tube piece extends from the transverse partition and is coaxially aligned to be received within a tubular receptacle which extends from the transverse wall. The tube piece and receptacle cooperate in engagement to restrict the flow and pressure of coolant beneath the transverse partition and thereby minimize upward forces tending to expel the inner <span class="hlt">conduit</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2013-10-16/pdf/2013-24464.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2013-10-16/pdf/2013-24464.pdf"><span>78 FR 62324 - Village of Oak Lawn, Illinois; Notice of Preliminary Determination of a Qualifying <span class="hlt">Conduit</span>...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2013-10-16</p> <p>... Energy Regulatory Commission Village of Oak Lawn, Illinois; Notice of Preliminary Determination of a..., Village of Oak Lawn, Illinois (Oak Lawn) filed a notice of intent to construct a qualifying <span class="hlt">conduit</span>... Hydroelectric Turbine Installation Project would utilize Oak Lawn's water distribution system, and it would be...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2013-11-13/pdf/2013-27043.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2013-11-13/pdf/2013-27043.pdf"><span>78 FR 68052 - Town of Telluride, Colorado; Notice of Preliminary Determination of a Qualifying <span class="hlt">Conduit</span>...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2013-11-13</p> <p>.../ Statutory provision Description N) FPA 30(a)(3)(A), as amended by The <span class="hlt">conduit</span> the Y HREA. facility uses is a... the generation of electricity. FPA 30(a)(3)(C)(i), as amended The facility is Y by HREA. constructed, operated, or maintained for the generation of electric power and uses for such generation only the...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2013-10-18/pdf/2013-24483.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2013-10-18/pdf/2013-24483.pdf"><span>78 FR 62351 - North Side Canal Company; Notice of Preliminary Determination of a Qualifying <span class="hlt">Conduit</span> Hydropower...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2013-10-18</p> <p>... (Y/N) FPA 30(a)(3)(A), as amended by The <span class="hlt">conduit</span> the facility Y HREA. uses is a tunnel, canal... of electricity. FPA 30(a)(3)(C)(i), as amended by The facility is Y HREA. constructed, operated, or maintained for the generation of electric power and uses for such generation only the hydroelectric potential...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2013-09-16/pdf/2013-22434.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2013-09-16/pdf/2013-22434.pdf"><span>78 FR 56872 - City of Barre, Vermont; Notice of Preliminary Determination of a Qualifying <span class="hlt">Conduit</span> Hydropower...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2013-09-16</p> <p>... Efficiency Act of 2013 (HREA). The Nelson Street 17 kW In-<span class="hlt">Conduit</span> Hydroelectric Net-Metered Project would be... system at http://www.ferc.gov/docs-filing/efiling.asp . Commenters can submit brief comments up to 6,000....asp . You must include your name and contact information at the end of your comments. For assistance...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21525148','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21525148"><span>Novel use of biodegradable casein <span class="hlt">conduits</span> for guided peripheral nerve regeneration.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hsiang, Shih-Wei; Tsai, Chin-Chuan; Tsai, Fuu-Jen; Ho, Tin-Yun; Yao, Chun-Hsu; Chen, Yueh-Sheng</p> <p>2011-11-07</p> <p>Recent advances in nerve repair technology have focused on finding more biocompatible, non-toxic materials to imitate natural peripheral nerve components. In this study, casein protein cross-linked with naturally occurring genipin (genipin-cross-linked casein (GCC)) was used for the first time to make a biodegradable <span class="hlt">conduit</span> for peripheral nerve repair. The GCC <span class="hlt">conduit</span> was dark blue in appearance with a concentric and round lumen. Water uptake, contact angle and mechanical tests indicated that the <span class="hlt">conduit</span> had a high stability in water and did not collapse and cramped with a sufficiently high level of mechanical properties. Cytotoxic testing and terminal deoxynucleotidyl transferase dUTP nick-end labelling assay showed that the GCC was non-toxic and non-apoptotic, which could maintain the survival and outgrowth of Schwann cells. Non-invasive real-time nuclear factor-κB bioluminescence imaging accompanied by histochemical assessment showed that the GCC was highly biocompatible after subcutaneous implantation in transgenic mice. Effectiveness of the GCC <span class="hlt">conduit</span> as a guidance channel was examined as it was used to repair a 10 mm gap in the rat sciatic nerve. Electrophysiology, labelling of calcitonin gene-related peptide in the lumbar spinal cord, and histology analysis all showed a rapid morphological and functional recovery for the disrupted nerves. Therefore, we conclude that the GCC can offer great nerve regeneration characteristics and can be a promising material for the successful repair of peripheral nerve defects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2013-10-23/pdf/2013-24739.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2013-10-23/pdf/2013-24739.pdf"><span>78 FR 63176 - Notice of Preliminary Determination of a Qualifying <span class="hlt">Conduit</span> Hydropower Facility and Soliciting...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2013-10-23</p> <p>... Facility and Soliciting Comments and Motions To Intervene; Orchard City, Colorado On October 7, 2013, Orchard City, Colorado (Orchard City) filed a notice of intent to construct a qualifying <span class="hlt">conduit</span>... Hydropower Regulatory Efficiency Act of 2013 (HREA). The 22 kW Orchard City Water Treatment Plant...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2010-12-10/pdf/2010-31039.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2010-12-10/pdf/2010-31039.pdf"><span>75 FR 77000 - South Coast <span class="hlt">Conduit</span>/Upper Reach Reliability Project, Santa Barbara County, CA</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2010-12-10</p> <p>... Bureau of Reclamation South Coast <span class="hlt">Conduit</span>/Upper Reach Reliability Project, Santa Barbara County, CA... reliability to Cachuma Project (CP) and State Water Project (SWP) customers on the South Coast of Santa....gov , or from Ms. Kate Rees, Cachuma Operation and Maintenance Board, 3301 Laurel Canyon Road,...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3694360','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3694360"><span>3D Bioprinting of Heterogeneous Aortic Valve <span class="hlt">Conduits</span> with Alginate/Gelatin Hydrogels</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Duan, Bin; Hockaday, Laura A.; Kang, Kevin H.; Butcher, Jonathan T.</p> <p>2013-01-01</p> <p>Heart valve disease is a serious and growing public health problem for which prosthetic replacement is most commonly indicated. Current prosthetic devices are inadequate for younger adults and growing children. Tissue engineered living aortic valve <span class="hlt">conduits</span> have potential for remodeling, regeneration, and growth, but fabricating natural anatomical complexity with cellular heterogeneity remain challenging. In the current study, we implement 3D bioprinting to fabricate living alginate/gelatin hydrogel valve <span class="hlt">conduits</span> with anatomical architecture and direct incorporation of dual cell types in a regionally constrained manner. Encapsulated aortic root sinus smooth muscle cells (SMC) and aortic valve leaflet interstitial cells (VIC) were viable within alginate/gelatin hydrogel discs over 7 days in culture. Acellular 3D printed hydrogels exhibited reduced modulus, ultimate strength, and peak strain reducing slightly over 7-day culture, while the tensile biomechanics of cell-laden hydrogels were maintained. Aortic valve <span class="hlt">conduits</span> were successfully bioprinted with direct encapsulation of SMC in the valve root and VIC in the leaflets. Both cell types were viable (81.4±3.4% for SMC and 83.2±4.0% for VIC) within 3D printed tissues. Encapsulated SMC expressed elevated alpha-smooth muscle actin when printed in stiff matrix, while VIC expressed elevated vimentin in soft matrix. These results demonstrate that anatomically complex, heterogeneously encapsulated aortic valve hydrogel <span class="hlt">conduits</span> can be fabricated with 3D bioprinting. PMID:23015540</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21371024','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21371024"><span>Modifications to the <span class="hlt">Conduit</span> Flow Process Mode 2 for MODFLOW-2005.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Reimann, Thomas; Birk, Steffen; Rehrl, Christoph; Shoemaker, W Barclay</p> <p>2012-01-01</p> <p>As a result of rock dissolution processes, karst aquifers exhibit highly conductive features such as caves and <span class="hlt">conduits</span>. Within these structures, groundwater flow can become turbulent and therefore be described by nonlinear gradient functions. Some numerical groundwater flow models explicitly account for pipe hydraulics by coupling the continuum model with a pipe network that represents the <span class="hlt">conduit</span> system. In contrast, the <span class="hlt">Conduit</span> Flow Process Mode 2 (CFPM2) for MODFLOW-2005 approximates turbulent flow by reducing the hydraulic conductivity within the existing linear head gradient of the MODFLOW continuum model. This approach reduces the practical as well as numerical efforts for simulating turbulence. The original formulation was for large pore aquifers where the onset of turbulence is at low Reynolds numbers (1 to 100) and not for <span class="hlt">conduits</span> or pipes. In addition, the existing code requires multiple time steps for convergence due to iterative adjustment of the hydraulic conductivity. Modifications to the existing CFPM2 were made by implementing a generalized power function with a user-defined exponent. This allows for matching turbulence in porous media or pipes and eliminates the time steps required for iterative adjustment of hydraulic conductivity. The modified CFPM2 successfully replicated simple benchmark test problems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26821785','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26821785"><span>A New Equation Solver for Modeling Turbulent Flow in Coupled Matrix-<span class="hlt">Conduit</span> Flow Models.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hubinger, Bernhard; Birk, Steffen; Hergarten, Stefan</p> <p>2016-07-01</p> <p>Karst aquifers represent dual flow systems consisting of a highly conductive <span class="hlt">conduit</span> system embedded in a less permeable rock matrix. Hybrid models iteratively coupling both flow systems generally consume much time, especially because of the nonlinearity of turbulent <span class="hlt">conduit</span> flow. To reduce calculation times compared to those of existing approaches, a new iterative equation solver for the <span class="hlt">conduit</span> system is developed based on an approximated Newton-Raphson expression and a Gauß-Seidel or successive over-relaxation scheme with a single iteration step at the innermost level. It is implemented and tested in the research code CAVE but should be easily adaptable to similar models such as the <span class="hlt">Conduit</span> Flow Process for MODFLOW-2005. It substantially reduces the computational effort as demonstrated by steady-state benchmark scenarios as well as by transient karst genesis simulations. Water balance errors are found to be acceptable in most of the test cases. However, the performance and accuracy may deteriorate under unfavorable conditions such as sudden, strong changes of the flow field at some stages of the karst genesis simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title26-vol2/pdf/CFR-2010-title26-vol2-sec1-67-3.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title26-vol2/pdf/CFR-2010-title26-vol2-sec1-67-3.pdf"><span>26 CFR 1.67-3 - Allocation of expenses by real estate mortgage investment <span class="hlt">conduits</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-04-01</p> <p>... 26 Internal Revenue 2 2010-04-01 2010-04-01 false Allocation of expenses by real estate mortgage investment <span class="hlt">conduits</span>. 1.67-3 Section 1.67-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE... Gross Income, and Taxable Income § 1.67-3 Allocation of expenses by real estate mortgage...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2013-11-20/pdf/2013-27746.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2013-11-20/pdf/2013-27746.pdf"><span>78 FR 69662 - Browns Valley Irrigation District; Notice of Preliminary Determination of a Qualifying <span class="hlt">Conduit</span>...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2013-11-20</p> <p>... Energy Regulatory Commission Browns Valley Irrigation District; Notice of Preliminary Determination of a..., Browns Valley Irrigation District (BVID) filed a notice of intent to construct a qualifying <span class="hlt">conduit</span>..., California. Applicant Contact: Walter Cotter, Browns Valley Irrigation District, 9370 Browns Valley School...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2011-08-29/pdf/2011-21983.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2011-08-29/pdf/2011-21983.pdf"><span>76 FR 53678 - Calleguas Municipal Water District Notice of Surrender of Exemption (<span class="hlt">Conduit</span>)</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2011-08-29</p> <p>... Federal Energy Regulatory Commission Calleguas Municipal Water District Notice of Surrender of Exemption (<span class="hlt">Conduit</span>) Pursuant to section 4.95(a) of the Commission's regulations,\\1\\ Calleguas Municipal Water... exemption for Project No. 11651 on June 7, 1999. Calleguas Municipal Water District, 87 FERC ] 62,256...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JMiMi..26d5016L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JMiMi..26d5016L"><span>Nerve growth factor released from a novel PLGA nerve <span class="hlt">conduit</span> can improve axon growth</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lin, Keng-Min; Shea, Jill; Gale, Bruce K.; Sant, Himanshu; Larrabee, Patti; Agarwal, Jay</p> <p>2016-04-01</p> <p>Nerve injury can occur due to penetrating wounds, compression, traumatic stretch, and cold exposure. Despite prompt repair, outcomes are dismal. In an attempt to help resolve this challenge, in this work, a poly-lactic-co-glycolic acid (PLGA) nerve <span class="hlt">conduit</span> with associated biodegradable drug reservoir was designed, fabricated, and tested. Unlike current nerve <span class="hlt">conduits</span>, this device is capable of fitting various clinical scenarios by delivering different drugs without reengineering the whole system. To demonstrate the potential of this device for nerve repair, a series of experiments were performed using nerve growth factor (NGF). First, an NGF dosage curve was developed to determine the minimum NGF concentration for optimal axonal outgrowth on chick dorsal root ganglia (DRG) cells. Next, PLGA devices loaded with NGF were evaluated for sustained drug release and axon growth enhancement with the released drug. A 20 d in vitro release test was conducted and the nerve <span class="hlt">conduit</span> showed the ability to meet and maintain the minimum NGF requirement determined previously. Bioactivity assays of the released NGF showed that drug released from the device between the 15th and 20th day could still promote axon growth (76.6-95.7 μm) in chick DRG cells, which is in the range of maximum growth. These novel drug delivery <span class="hlt">conduits</span> show the ability to deliver NGF at a dosage that efficiently promotes ex vivo axon growth and have the potential for in vivo application to help bridge peripheral nerve gaps.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21608736','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21608736"><span>Percutaneous Transthoracic Computed Tomography-Guided AICD Insertion in a Patient with Extracardiac Fontan <span class="hlt">Conduit</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Murphy, Darra T. Moynagh, Michael R.; Walsh, Kevin P.; Noelke, Lars; Murray, John G.</p> <p>2011-02-15</p> <p>Percutaneous pulmonary venous atrial puncture was performed under computed tomography guidance to successfully place an automated implantable cardiac defibrillator into a 26-year-old patient with extracardiac Fontan <span class="hlt">conduit</span> who had presented with two out-of-hospital cardiac arrests. The procedure avoided the need for lead placement at thoracotomy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.H23F1342H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.H23F1342H"><span>Analogue modelisation of flow through a double porosity media with discrete <span class="hlt">conduits</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hakoun, V.; Pistre, S.; Karst; heterogeneous media-Hydrogeology, hydraulics; transfers</p> <p>2011-12-01</p> <p>In this study we describe a three dimensional meter scale experimental system used to investigate flow through a double porosity media that includes discrete flow <span class="hlt">conduits</span>. This hybrid discrete-continuum approach is used to simulate water flow in karstic carbonate aquifers. A rectangular tank is filled with stacked ceramic foam blocks laterally separated with a constant aperture. The tank outlet is connected to a drilled <span class="hlt">conduit</span> network that follows the overlying aperture scheme at the lower base of the system. Above the system, an artificial rain is set with a sprinkler. Working with an analogue model seems interesting as materials, initial and boundary conditions are fully known. Ceramic foam provides a uniform matrix material allowing different porosities and hydraulic conductivities. The modulability of the aperture pattern and size let different experiment setting possibilities. A variation in the drilled number of holes in the <span class="hlt">conduit</span> network will change its draining capacity. And, finally the artificial rain rate and location are well characterized. The system is adequately instrumented in order to 1) observe hydraulic head distributions in both matrix and fracture medium and 2) record spring flow fluctuations. Moreover, any experience is very reproducible. This analogue modeling approach allows an observation of both fracture and matrix flow contribution to a spring with a drained double porosity media with discrete <span class="hlt">conduits</span>. Comparison of in situ measured data with a finite element numerical model and an analytical solution are shown.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2013-10-08/pdf/2013-24394.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2013-10-08/pdf/2013-24394.pdf"><span>78 FR 61958 - San Juan County Historical Society; Notice of Preliminary Determination of A Qualifying <span class="hlt">Conduit</span>...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2013-10-08</p> <p>... Energy Regulatory Commission San Juan County Historical Society; Notice of Preliminary Determination of A..., San Juan County Historical Society filed a notice of intent to construct a qualifying <span class="hlt">conduit</span>... Historical Society, P.O. Box 154, Silverton, CO 81433, Phone No. (970) 387-5488. FERC Contact: Robert...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28975768','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28975768"><span>A Physicochemically Optimized and Neuroconductive Biphasic Nerve Guidance <span class="hlt">Conduit</span> for Peripheral Nerve Repair.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ryan, Alan J; Lackington, William A; Hibbitts, Alan J; Matheson, Austyn; Alekseeva, Tijna; Stejskalova, Anna; Roche, Phoebe; O'Brien, Fergal J</p> <p>2017-10-04</p> <p>Clinically available hollow nerve guidance <span class="hlt">conduits</span> (NGCs) have had limited success in treating large peripheral nerve injuries. This study aims to develop a biphasic NGC combining a physicochemically optimized collagen outer <span class="hlt">conduit</span> to bridge the transected nerve, and a neuroconductive hyaluronic acid-based luminal filler to support regeneration. The outer <span class="hlt">conduit</span> is mechanically optimized by manipulating crosslinking and collagen density, allowing the engineering of a high wall permeability to mitigate the risk of neuroma formation, while also maintaining physiologically relevant stiffness and enzymatic degradation tuned to coincide with regeneration rates. Freeze-drying is used to seamlessly integrate the luminal filler into the <span class="hlt">conduit</span>, creating a longitudinally aligned pore microarchitecture. The luminal stiffness is modulated to support Schwann cells, with laminin incorporation further enhancing bioactivity by improving cell attachment and metabolic activity. Additionally, this biphasic NGC is shown to support neurogenesis and gliogenesis of neural progenitor cells and axonal outgrowth from dorsal root ganglia. These findings highlight the paradigm that a successful NGC requires the concerted optimization of both a mechanical support phase capable of bridging a nerve defect and a neuroconductive phase with an architecture capable of supporting both Schwann cells and neurons in order to achieve functional regenerative outcome. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=film&pg=2&id=EJ1034467','ERIC'); return false;" href="http://eric.ed.gov/?q=film&pg=2&id=EJ1034467"><span>Jean Vigo's "Zéro De <span class="hlt">Conduite</span>" and the Spaces of Revolt</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Vanobbergen, Bruno; Grosvenor, Ian; Simon, Frank</p> <p>2014-01-01</p> <p>In this article we will contribute to the contemporary theoretical debate about film by considering, from a history-of-education perspective, the film "Zéro de <span class="hlt">conduite</span>" by Jean Vigo (1905--1934). This film is classified under the umbrella of "poetic realism": a product of "cinéma de gauche" and an avant-gardist,…</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=dynamic+AND+websites&pg=5&id=ED524952','ERIC'); return false;" href="http://eric.ed.gov/?q=dynamic+AND+websites&pg=5&id=ED524952"><span>The <span class="hlt">Conduit</span> and Whirlpooling: A New Theory of Knowledge Constitution and Dispersion</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Nzegwu, Azuka</p> <p>2010-01-01</p> <p>There is a new epistemological approach for exploring knowledge constitution and dispersal in a dynamic Web ecosystem. The approach has three pivots. The first presents virtual whirlpools as knowledge systems. The second introduces the creator of the system as the <span class="hlt">Conduit</span>. The third formulates a theory of knowledge that involves the collective…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23890811','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23890811"><span>Bronchovascular reconstruction with a bovine pericardial <span class="hlt">conduit</span> and surgical reintervention due to thrombosis with revascularisation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Peña, Emilio; Blanco, Montserrat; Otero, Teresa</p> <p>2014-01-01</p> <p>We present the case of a 57-year-old male with left hilar squamous cell carcinoma infiltrating the pulmonary artery and in whom a sleeve bronchoplasty and angioplasty were performed using a bovine pericardial <span class="hlt">conduit</span>. Three days post-operatively, graft thrombosis was detected; thrombectomy and graft reconstruction were performed with revascularisation of the graft.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4146035','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4146035"><span>Nanofibrous nerve <span class="hlt">conduits</span> for repair of 30-mm-long sciatic nerve defects</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Biazar, Esmaeil; Keshel, Saeed Heidari; Pouya, Majid; Rad, Hadi; Nava, Melody Omrani; Azarbakhsh, Mohammad; Hooshmand, Shirin</p> <p>2013-01-01</p> <p>It has been confirmed that nanofibrous poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nerve <span class="hlt">conduit</span> can promote peripheral nerve regeneration in rats. However, its efficiency in repair of over 30-mm-long sciatic nerve defects needs to be assessed. In this study, we used a nanofibrous poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nerve <span class="hlt">conduit</span> to bridge a 30-mm-long gap in the rat sciatic nerve. At 4 months after nerve <span class="hlt">conduit</span> implantation, regenerated nerves were cally observed and histologically assessed. In the nanofibrous graft, the rat sciatic nerve trunk had been reconstructed by restoration of nerve continuity and formation of myelinated nerve fiber. There were Schwann cells and glial cells in the regenerated nerves. Masson's trichrome staining showed that there were no pathological changes in the size and structure of gastrocnemius muscle cells on the operated side of rats. These findings suggest that nanofibrous poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nerve <span class="hlt">conduit</span> is suitable for repair of long-segment sciatic nerve defects. PMID:25206536</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70035490','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70035490"><span>Modifications to the <span class="hlt">Conduit</span> Flow Process Mode 2 for MODFLOW-2005</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Reimann, T.; Birk, S.; Rehrl, C.; Shoemaker, W.B.</p> <p>2012-01-01</p> <p>As a result of rock dissolution processes, karst aquifers exhibit highly conductive features such as caves and <span class="hlt">conduits</span>. Within these structures, groundwater flow can become turbulent and therefore be described by nonlinear gradient functions. Some numerical groundwater flow models explicitly account for pipe hydraulics by coupling the continuum model with a pipe network that represents the <span class="hlt">conduit</span> system. In contrast, the <span class="hlt">Conduit</span> Flow Process Mode 2 (CFPM2) for MODFLOW-2005 approximates turbulent flow by reducing the hydraulic conductivity within the existing linear head gradient of the MODFLOW continuum model. This approach reduces the practical as well as numerical efforts for simulating turbulence. The original formulation was for large pore aquifers where the onset of turbulence is at low Reynolds numbers (1 to 100) and not for <span class="hlt">conduits</span> or pipes. In addition, the existing code requires multiple time steps for convergence due to iterative adjustment of the hydraulic conductivity. Modifications to the existing CFPM2 were made by implementing a generalized power function with a user-defined exponent. This allows for matching turbulence in porous media or pipes and eliminates the time steps required for iterative adjustment of hydraulic conductivity. The modified CFPM2 successfully replicated simple benchmark test problems. ?? 2011 The Author(s). Ground Water ?? 2011, National Ground Water Association.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/8102650','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/8102650"><span>Ileal <span class="hlt">conduit</span> for reconstruction of the duodenum following right hemicolectomy and pancreaticoduodenectomy for malignant duodenocolic fistula.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ohri, A K; Ohri, S K</p> <p>1993-06-01</p> <p>We describe a case of malignant duodenocolic fistula in which after a radical resection of right hemicolectomy and pancreaticoduodenectomy, the duodenal defect was reconstructed using a <span class="hlt">conduit</span> of transposed ileum. This technique, not previously described, offers an alternative to 'duodenal patching', which allows only limited duodenal resection, or gastroenterostomy with its attendant side-effects such as dumping syndrome.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/id0443.photos.220095p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/id0443.photos.220095p/"><span>ETR, TRA642. BEFORE BASEMENT FLOOR IS PLACED, WORKERS LAY <span class="hlt">CONDUIT</span> ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>ETR, TRA-642. BEFORE BASEMENT FLOOR IS PLACED, WORKERS LAY <span class="hlt">CONDUIT</span> RUNS THAT WILL LIE BELOW IT. INL NEGATIVE NO. 56-541. Jack L. Anderson, Photographer, 2/15/1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=static+AND+web&pg=3&id=ED524952','ERIC'); return false;" href="https://eric.ed.gov/?q=static+AND+web&pg=3&id=ED524952"><span>The <span class="hlt">Conduit</span> and Whirlpooling: A New Theory of Knowledge Constitution and Dispersion</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Nzegwu, Azuka</p> <p>2010-01-01</p> <p>There is a new epistemological approach for exploring knowledge constitution and dispersal in a dynamic Web ecosystem. The approach has three pivots. The first presents virtual whirlpools as knowledge systems. The second introduces the creator of the system as the <span class="hlt">Conduit</span>. The third formulates a theory of knowledge that involves the collective…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JVGR..302....1K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JVGR..302....1K"><span>Numerical investigation of temporal changes in volcanic deformation caused by a gas slug ascent in the <span class="hlt">conduit</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kawaguchi, Ryohei; Nishimura, Takeshi</p> <p>2015-09-01</p> <p>Strombolian type eruptions are considered to be generated by a sudden release of a large gas slug that migrates upward in the <span class="hlt">conduit</span> filled with a low viscous basaltic magma. We examine volcano deformations caused by such a gas slug to understand the Strombolian eruption mechanism from geodetic observation data. We model spatio-temporal pressure changes in the <span class="hlt">conduit</span> by using a gas slug ascent model presented by James et al. (2008). As a gas slug ascends in the <span class="hlt">conduit</span>, its volume expands because of depressurization. Hence, the magma head lifts up in the <span class="hlt">conduit</span> and the upper part of the <span class="hlt">conduit</span> wall is stressed. In the <span class="hlt">conduit</span>, magma pressure increases with depth according to the bulk density of magma: the gas slug part with a low density is characterized by a small pressure gradient, while the other parts, consisting of melt, are characterized by a large pressure gradient. We numerically calculate volcano deformations caused by the spatio-temporal changes of magma pressure predicted from the basic equations representing gas slug locations in the <span class="hlt">conduit</span>. Simulation results show that the radial and vertical displacements and tilt changes indicate volcano deformations that represent the inflation originating from the stress increase at the upper part of <span class="hlt">conduit</span>. As the gas slug reaches the shallow part of <span class="hlt">conduit</span>, the rate of inflation observed in the radial displacement decreases, the vertical displacement starts to move downward, and the tilt turns to show down toward the crater. These deflation signals are caused by a moving deflation source in the <span class="hlt">conduit</span> that is formed beneath the gas slug. Since these predicted features are not observed in the tilt records associated with explosions at Stromboli volcano (Genco and Ripepe, 2010), it is necessary to modify the gas slug ascent model or to introduce other mechanisms to better understand the magma dynamics of Strombolian eruption.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.C41D0692C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.C41D0692C"><span>Surface Features Parameterization and Equivalent Roughness Height Estimation of a Real Subglacial <span class="hlt">Conduit</span> in the Arctic</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Y.; Liu, X.; Manko ff, K. D.; Gulley, J. D.</p> <p>2016-12-01</p> <p>The surfaces of subglacial <span class="hlt">conduits</span> are very complex, coupling multi-scale roughness, large sinuosity, and cross-sectional variations together. Those features significantly affect the friction law and drainage efficiency inside the <span class="hlt">conduit</span> by altering velocity and pressure distributions, thus posing considerable influences on the dynamic development of the <span class="hlt">conduit</span>. Parameterizing the above surface features is a first step towards understanding their hydraulic influences. A Matlab package is developed to extract the roughness field, the <span class="hlt">conduit</span> centerline, and associated area and curvature data from the <span class="hlt">conduit</span> surface, acquired from 3D scanning. By using those data, the characteristic vertical and horizontal roughness scales are then estimated based on the structure functions. The centerline sinuosities, defined through three concepts, i.e., the traditional definition of a fluvial river, entropy-based sinuosity, and curvature-based sinuosity, are also calculated and compared. The cross-sectional area and equivalent circular diameter along the centerline are also calculated. Among those features, the roughness is especially important due to its pivotal role in determining the wall friction, and thus an estimation of the equivalent roughness height is of great importance. To achieve such a goal, the original <span class="hlt">conduit</span> is firstly simplified into a straight smooth pipe with the same volume and centerline length, and the roughness field obtained above is then reconstructed into the simplified pipe. An OpenFOAM-based Large-eddy-simulation (LES) is then performed based on the reconstructed pipe. Considering that the Reynolds number is of the order 106, and the relative roughness is larger than 5% for 60% of the <span class="hlt">conduit</span>, we test the validity of the resistance law for completely rough pipe. The friction factor is calculated based on the pressure drop and mean velocity in the simulation. Working together, the equivalent roughness height can be calculated. However, whether the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.V21B2716C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.V21B2716C"><span>The role of shear heating in obsidian formation within volcanic <span class="hlt">conduits</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Curry, A. C.</p> <p>2013-12-01</p> <p>While most volcanic rocks contain a significant amount of crystals (15-35 vol%), obsidian is unusual because it contains < 2 vol% phenocrysts. The few phenocrysts in obsidian are evidence for some crystallization, but the relative paucity reflects conditions in which crystallization is inhibited. The causes of these conditions in obsidian magmas are poorly understood. One way to inhibit crystallization and resorb crystals is to increase temperature. Shear heating is a potentially important source of heat in high-silica rhyolites due to their high viscosity, yet it is seldom accounted for in the thermal budgets of ascending magmas. This study combines mineralogical analysis of obsidian with numerical models of ascending, high-silica magma in order to examine an alternate hypothesis for obsidian formation in which shear heating inhibits crystallization and resorbs crystals. Using the finite-element solver COMSOL Multiphysics, this study models a planar dike 5 m wide and 1 km long. Temperatures increase up to 300 K above initial magma temperatures at <span class="hlt">conduit</span> edges, which enable velocities and fluxes above Poiseuille solutions. These temperature increases are 150-200 K higher than those found by existing numerical models that account for shear heating in volcanic <span class="hlt">conduits</span>. Based on velocities in the outer edge of the <span class="hlt">conduit</span>, residence times of crystals in hotter magma range from 6 minutes to 58 days in a 1 km <span class="hlt">conduit</span>; longer <span class="hlt">conduits</span> increase residence time. Furthermore, complex <span class="hlt">conduit</span> geometry can cause separation of laminar flow lines which would distribute hotter magma to other parts of the <span class="hlt">conduit</span>. Longer residence times and higher temperatures favor crystal resorption. Modal analyses of obsidian in this study reflect a regional lack of quartz and sanidine phenocrysts in eastern California obsidian. This regional lack is unpredicted by the dominant hypotheses of obsidian formation and unexpected based on the mineralogy of other high-silica rhyolites. Phenocryst</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title26-vol9/pdf/CFR-2011-title26-vol9-sec1-881-3.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title26-vol9/pdf/CFR-2011-title26-vol9-sec1-881-3.pdf"><span>26 CFR 1.881-3 - <span class="hlt">Conduit</span> financing arrangements.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-04-01</p> <p>... solely from ownership of a <span class="hlt">controlling</span> interest in the issuer in cases where the <span class="hlt">control</span> does not arise... capital by entering into transactions with unrelated persons. (3) Special rule for trade receivables and... intermediate entity nets intercompany trade payables and receivables arising from transactions among the other...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRB..119.5305K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRB..119.5305K"><span>Welding of pyroclastic <span class="hlt">conduit</span> infill: A mechanism for cyclical explosive eruptions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kolzenburg, S.; Russell, J. K.</p> <p>2014-07-01</p> <p>Vulcanian-style eruptions are small- to moderate-sized, singular to cyclical events commonly having volcanic explosivity indices of 1-3. They produce pyroclastic flows, disperse tephra over considerable areas, and can occur as precursors to larger (e.g., Plinian) eruptions. The fallout deposits of the 2360 B.P. eruption of Mount Meager, BC, Canada, contain bread-crusted blocks of welded breccia as accessory lithics. They display a range of compaction/welding intensity and provide a remarkable opportunity to constrain the nature and timescales of mechanical processes operating within explosive volcanic <span class="hlt">conduits</span> during repose periods between eruptive cycles. We address the deformation and porosity/permeability reduction within natural pyroclastic deposits infilling volcanic <span class="hlt">conduits</span>. We measure the porosity, permeability, and ultrasonic wave velocities for a suite of samples and quantify the strain recorded by pumice clasts. We explore the correlations between the physical properties and deformation fabric. Based on these correlations, we reconstruct the deformation history within the <span class="hlt">conduit</span>, model the permeability reduction timescales, and outline the implications for the repressurization of the volcanic <span class="hlt">conduit</span>. Our results highlight a profound directionality in the measured physical properties of these samples related to the deformation-induced fabric. Gas permeability varies drastically with increasing strain and decreasing porosity along the compaction direction of the fabric but varies little along the elongation direction of the fabric. The deformation fabric records a combination of compaction within the <span class="hlt">conduit</span> and postcompaction stretching associated with subsequent eruption. Model timescales of these processes are in good agreement with repose periods of cyclic vulcanian eruptions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5034629','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/5034629"><span>Flowmeter for determining average rate of flow of liquid in a <span class="hlt">conduit</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Kennerly, J.M.; Lindner, G.M.; Rowe, J.C.</p> <p>1981-04-30</p> <p>This invention is a compact, precise, and relatively simple device for use in determining the average rate of flow of a liquid through a <span class="hlt">conduit</span>. The liquid may be turbulent and contain bubbles of gas. In a preferred embodiment, the flowmeter includes an electrical circuit and a flow vessel which is connected as a segment of the <span class="hlt">conduit</span> conveying the liquid. The vessel is provided with a valved outlet and is partitioned by a vertical baffle into coaxial chambers whose upper regions are vented to permit the escape of gas. The inner chamber receives turbulent downflowing liquid from the <span class="hlt">conduit</span> and is sized to operate at a lower pressure than the <span class="hlt">conduit</span>, thus promoting evolution of gas from the liquid. Lower zones of the two chambers are interconnected so that the downflowing liquid establishes liquid levels in both chambers. The liquid level in the outer chamber is comparatively calm, being to a large extent isolated from the turbulence in the inner chamber once the liquid in the outer chamber has risen above the liquid-introduction zone for that chamber. Lower and upper probes are provided in the outer chamber for sensing the liquid level therein at points above its liquid-introduction zone. An electrical circuit is connected to the probes to display the time required for the liquid level in the outer chamber to successively contact the lower and upper probes. The average rate of flow through the <span class="hlt">conduit</span> can be determined from the above-mentioned time and the vessel volume filled by the liquid during that time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/864439','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/864439"><span>Flowmeter for determining average rate of flow of liquid in a <span class="hlt">conduit</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Kennerly, John M.; Lindner, Gordon M.; Rowe, John C.</p> <p>1982-01-01</p> <p>This invention is a compact, precise, and relatively simple device for use in determining the average rate of flow of a liquid through a <span class="hlt">conduit</span>. The liquid may be turbulent and contain bubbles of gas. In a preferred embodiment, the flowmeter includes an electrical circuit and a flow vessel which is connected as a segment of the <span class="hlt">conduit</span> conveying the liquid. The vessel is provided with a valved outlet and is partitioned by a vertical baffle into coaxial chambers whose upper regions are vented to permit the escape of gas. The inner chamber receives turbulent downflowing liquid from the <span class="hlt">conduit</span> and is sized to operate at a lower pressure than the <span class="hlt">conduit</span>, thus promoting evolution of gas from the liquid. Lower zones of the two chambers are interconnected so that the downflowing liquid establishes liquid levels in both chambers. The liquid level in the outer chamber is comparatively calm, being to a large extent isolated from the turbulence in the inner chamber once the liquid in the outer chamber has risen above the liquid-introduction zone for that chamber. Lower and upper probes are provided in the outer chamber for sensing the liquid level therein at points above its liquid-introduction zone. An electrical circuit is connected to the probes to display the time required for the liquid level in the outer chamber to successively contact the lower and upper probes. The average rate of flow through the <span class="hlt">conduit</span> can be determined from the above-mentioned time and the vessel volume filled by the liquid during that time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70033651','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70033651"><span>Tile drainage as karst: <span class="hlt">Conduit</span> flow and diffuse flow in a tile-drained watershed</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Schilling, K.E.; Helmers, M.</p> <p>2008-01-01</p> <p>The similarity of tiled-drained watersheds to karst drainage basins can be used to improve understanding of watershed-scale nutrient losses from subsurface tile drainage networks. In this study, short-term variations in discharge and chemistry were examined from a tile outlet collecting subsurface tile flow from a 963 ha agricultural watershed. Study objectives were to apply analytical techniques from karst springs to tile discharge to evaluate water sources and estimate the loads of agricultural pollutants discharged from the tile with <span class="hlt">conduit</span>, intermediate and diffuse flow regimes. A two-member mixing model using nitrate, chloride and specific conductance was used to distinguish rainwater versus groundwater inputs. Results indicated that groundwater comprised 75% of the discharge for a three-day storm period and rainwater was primarily concentrated during the hydrograph peak. A contrasting pattern of solute concentrations and export loads was observed in tile flow. During base flow periods, tile flow consisted of diffuse flow from groundwater sources and contained elevated levels of nitrate, chloride and specific conductance. During storm events, suspended solids and pollutants adhered to soil surfaces (phosphorus, ammonium and organic nitrogen) were concentrated and discharged during the rapid, <span class="hlt">conduit</span> flow portion of the hydrograph. During a three-day period, <span class="hlt">conduit</span> flow occurred for 5.6% of the time but accounted for 16.5% of the total flow. Nitrate and chloride were delivered primarily with diffuse flow (more than 70%), whereas 80-94% of total suspended sediment, phosphorus and ammonium were exported with <span class="hlt">conduit</span> and intermediate flow regimes. Understanding the water sources contributing to tile drainage and the manner by which pollutant discharge occurs from these systems (<span class="hlt">conduit</span>, intermediate or diffuse flow) may be useful for designing, implementing and evaluating non-point source reduction strategies in tile-drained landscapes. ?? 2007 Elsevier B.V. All</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28718327','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28718327"><span>Fibrin Glue Increases the Tensile Strength of <span class="hlt">Conduit</span>-Assisted Primary Digital Nerve Repair.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Childe, Jessica R; Regal, Steven; Schimoler, Patrick; Kharlamov, Alexander; Miller, Mark C; Tang, Peter</p> <p>2017-02-01</p> <p>An ideal peripheral nerve repair construct does not currently exist. Our primary goal was to determine whether fibrin glue adds to the tensile strength of <span class="hlt">conduit</span>-assisted primary digital nerve repairs. Our secondary goal was to evaluate the impact of varying suture number and location on the tensile strength. Ninety cadaveric digital nerves were harvested and divided equally into the following repair groups: A (4/4), B (2/2), C (0/2), D (0/1), and E (0/0) with the first number referring to the number of sutures at the coaptation and the second number referring to the number of sutures at each proximal and distal end of the nerve-<span class="hlt">conduit</span> junction. When fibrin glue was added, the group was labeled prime. The nerve specimens were transected and then repaired with 8-0 nylon suture and <span class="hlt">conduit</span>. The tensile strength of the repairs was tested, and maximum failure load was determined. The results were analyzed with a 2-way analysis of variance. The Tukey post hoc test compared repair groups if the 2-way analysis of variance showed significance. Both suture group and glue presence significantly affected the maximum failure load. Increasing the number of sutures increased the maximum failure load, and the presence of fibrin glue also increased the failure load. Fibrin glue was found to increase the strength of <span class="hlt">conduit</span>-assisted primary digital nerve repairs. Furthermore, the number of sutures correlated to the strength of the repair. Fibrin glue may be added to a <span class="hlt">conduit</span>-assisted primary digital nerve repair to maintain strength and allow fewer sutures at the primary coaptation site.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003JVGR..120..141N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003JVGR..120..141N"><span>Coupled <span class="hlt">conduit</span> and atmospheric dispersal dynamics of the AD 79 Plinian eruption of Vesuvius</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neri, Augusto; Papale, Paolo; Del Seppia, Dario; Santacroce, Roberto</p> <p>2003-01-01</p> <p>The AD 79 eruption of Vesuvius is certainly one of the most investigated explosive eruptions in the world. This makes it particularly suitable for the application of numerical models since we can be quite confident about input data, and the model predictions can be compared with field-based reconstruction of the eruption dynamics. Magma ascent along the volcanic <span class="hlt">conduit</span> and the dispersal of pyroclasts in the atmosphere were simulated. The <span class="hlt">conduit</span> and atmospheric domain were coupled through the flow conditions computed at the <span class="hlt">conduit</span> exit. We simulated two different peak phases of the eruption which correspond to the emplacement of the white and gray magma types that produced Plinian fallout deposits with interlayered pyroclastic flow units during the gray phase. The input data, independently constrained and representative of each of the two eruptive phases, consist of liquid magma composition, crystal and water content, mass flow rate, and pressure-temperature-depth of the magma at the <span class="hlt">conduit</span> entrance. A parametric study was performed on the less constrained variables such as microlite content of magma, pressure at the <span class="hlt">conduit</span> entrance, and particle size representative of the eruptive mixture. Numerical results are substantially consistent with the reconstructed eruptive dynamics. In particular, the white eruption phase is found to lead to a fully buoyant eruption plume in all cases investigated, whereas the gray phase shows a more transitional character, i.e. the simultaneous production of a buoyant convective plume and pyroclastic surges, with a significant influence of the microlite content of magma in determining the partition of pyroclast mass between convective plumes and pyroclastic flows.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22887896','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22887896"><span>Effects of large-area irradiated laser phototherapy on peripheral nerve regeneration across a large gap in a biomaterial <span class="hlt">conduit</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shen, Chiung-Chyi; Yang, Yi-Chin; Liu, Bai-Shuan</p> <p>2013-01-01</p> <p>This paper proposes a novel biodegradable nerve <span class="hlt">conduit</span> comprising 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) cross-linked gelatin, annexed with β-tricalcium phosphate (TCP) ceramic particles (EDC-Gelatin-TCP, EGT). In this study, the EGT-implant site in rats was irradiated using a large-area 660 nm AlGaInP diode laser (50 mW) to investigate the feasibility of laser stimulation in the regeneration of a 15-mm transected sciatic nerve. The animals were divided into three groups: a sham-irradiated group (EGT/sham); an experimental group undergoing low-level laser (LLL) therapy (EGT/laser); a <span class="hlt">control</span> group undergoing autologous nerve grafts (autografts). Twelve weeks after implantation, walking track analysis showed a significantly higher sciatic functional index (p < 0.05) and improved toe spreading development in the EGT/laser and autograft groups than in the EGT/sham group. In electrophysiological measurement, both the mean peak amplitude and the area under the compound muscle action potential curves in the EGT/laser and autograft groups showed significantly improved functional recovery than the EGT/sham group (p < 0.05). Compared with the EGT/sham group, the EGT/laser and autograft groups displayed a reduction in muscular atrophy. Histomorphometric assessments revealed that the EGT/laser group had undergone more rapid nerve regeneration than the EGT/sham group. The laser-treated group also presented greater neural tissue area as well as larger axon diameter and thicker myelin sheath than the tube group without the laser treatment, indicating improved nerve regeneration. Thus, these assessments demonstrate that LLL therapy can accelerate the repair of a transected peripheral nerve in rats after being bridged with EGT <span class="hlt">conduit</span>. Copyright © 2012 Wiley Periodicals, Inc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70027071','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70027071"><span>Gas evolution in eruptive <span class="hlt">conduits</span>: Combining insights from high temperature and pressure decompression experiments with steady-state flow modeling</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Mangan, M.; Mastin, L.; Sisson, T.</p> <p>2004-01-01</p> <p>In this paper we examine the consequences of bubble nucleation mechanism on eruptive degassing of rhyolite magma. We use the results of published high temperature and pressure decompression experiments as input to a modified version of CONFLOW, the numerical model of Mastin and Ghiorso [(2000) U.S.G.S. Open-File Rep. 00-209, 53 pp.] and Mastin [(2002) Geochem. Geophys. Geosyst. 3, 10.1029/2001GC000192] for steady, two-phase flow in vertical <span class="hlt">conduits</span>. Synthesis of the available experimental data shows that heterogeneous nucleation is triggered at ??P 120-150 MPa, and leads to disequilibrium degassing at extreme H2O supersaturation. In this latter case, nucleation is an ongoing process <span class="hlt">controlled</span> by changing supersaturation conditions. Exponential bubble size distributions are often produced with number densities of 106-109 bubbles/cm3. Our numerical analysis adopts an end-member approach that specifically compares equilibrium degassing with delayed, disequilibrium degassing characteristic of homogeneously-nucleating systems. The disequilibrium simulations show that delaying nucleation until ??P =150 MPa restricts degassing to within ???1500 m of the surface. Fragmentation occurs at similar porosity in both the disequilibrium and equilibrium modes (???80 vol%), but at the distinct depths of ???500 m and ???2300 m, respectively. The vesiculation delay leads to higher pressures at equivalent depths in the <span class="hlt">conduit</span>, and the mass flux and exit pressure are each higher by a factor of ???2.0. Residual water contents in the melt reaching the vent are between 0.5 and 1.0 wt%, roughly twice that of the equilibrium model. ?? 2003 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFM.V21C0624T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFM.V21C0624T"><span>Continuous Gas Monitoring at the Unzen-<span class="hlt">Conduit</span>-Drilling USDP-4</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tretner, A.; Zimmer, M.; Erzinger, J.; Saito, M.; Nakada, S.</p> <p>2005-12-01</p> <p>Unzen Volcano, located in the Shimabara Peninsula, Kyushu, southwest Japan, was selected as one of the Decade Volcanoes of the United Nation's Decade of Natural Disaster Reduction, since it represents an important type of dangerous volcano. The last eruption (1990-95) was monitored and investigated in detail, yielding several models on the eruption mechanism and magmatic processes. The focus of USDP4 - drilling was to further clarify the regional crustal structure and magma evolution processes that <span class="hlt">control</span> the manner of growth and failure of the volcano. In addition, processes of <span class="hlt">conduit</span> formation, magma degassing, and magma's interaction with groundwater was investigated. Petrological investigations show, that Unzen magma in the <span class="hlt">conduit</span> contained 4-5 wt.% water, whereas water content of the lava at the surface is very small. It was modelled that the water was released at less that 1-2 km depth. In view of these constraints different physico-chemical models show a strong increase in magma viscosity and a pressure drop directly below the growing dome. The gas phase dissolved in the drill mud was analyzed continuously with an online gas monitoring system. The aim was to receive a gas profile along the whole borehole length in order to gain information on the volcano fluid circulation system, to detect possible pathways for gases produced during magma degassing, and to determine hydrothermal and/or volcanic fluid inflow horizons. N2, O2, CO2, CH4, H2S, H2, He and Ar analyses were achieved with a quadrupol mass spectrometer; 222Rn was measured with a Lucas cell alpha detecotor. This data and subsequent isotopic studies contribute in particular to the discussed models about the eruptive behavior of Mt. Unzen. However, limitations were given due to the extremely difficult drilling conditions. The highly fractured rock formation led to loss of drill mud circulation mainly in the shallow parts. First results show that significant fluid inflow horizons didn't occur above</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.3390C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.3390C"><span>Rheology contrast in the shallow <span class="hlt">conduit</span> and eruption dynamics at Stromboli: insights from analogue experiments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Capponi, Antonio; Lane, Stephen J.; James, Mike R.</p> <p>2014-05-01</p> <p>Strombolian eruptions result from the bursting of large individual gas pockets (slugs) in a low-viscosity magma. Scaled experimental investigations of the processes involved have generally been carried out in single Newtonian liquids, and have explored the dynamics of slug expansion, burst and their <span class="hlt">control</span> on the generation of geophysical signals. Such studies provide a thorough first order investigation of the mechanisms involved, but little attention has been given so far to the processes of slug expansion and burst in more complex fluids. Observations at Stromboli show that obstructions in the <span class="hlt">conduit</span> (due to, e.g., partial wall collapse or fall back in the vent of ejecta) can generate a viscous impedance within the upper portion of magma, leading to more violent eruptions. Petrological and textural data also suggest the presence of different magma rheologies due to degassing driven crystallisation. Here we use laboratory experiments to investigate the role of a vertical contrast in magma rheology on the dynamics of slug expansion and burst, and the resulting geophysical signals. The analogue materials used are silicon oil (μ = 0.1 Pa*s) capped with castor oil (μ = 1 Pa*s) to give a viscosity contrast of 10. Vertical pressure gradient is scaled by reducing the pressure at the top of the experimental apparatus with a vacuum pump. Pressure variations are measured at the top and bottom of the apparatus and correlated with high-speed imagery of the experiments and the results compared with <span class="hlt">control</span> experiments using single liquid. The thickness of the viscous plug was varied along with the gas volumes and the gas pressure at the liquid surface (1 kPa, 3 kPa and 300 Pa). Our results show that the thickness of the viscous plug strongly <span class="hlt">controls</span> slug expansion and systematically changes the magnitude of the associated pressure transients, favouring a more impulsive and energetic pressure release compared with the <span class="hlt">control</span> experiments. The intrusion of slugs in the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27173066','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27173066"><span>Smaller-Sized Expanded Polytetrafluoroethylene <span class="hlt">Conduits</span> With a Fan-Shaped Valve and Bulging Sinuses for Right Ventricular Outflow Tract Reconstruction.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yamashita, Eijiro; Yamagishi, Masaaki; Miyazaki, Takako; Maeda, Yoshinobu; Yamamoto, Yusuke; Kato, Nobuyasu; Asada, Satoshi; Hongu, Hisayuki; Yaku, Hitoshi</p> <p>2016-10-01</p> <p>One of the critical factors limiting <span class="hlt">conduit</span> longevity in right ventricular outflow tract (RVOT) reconstruction with homografts and xenografts is the small size of the <span class="hlt">conduit</span>. The aim of our study was to assess the outcome of using smaller-sized expanded polytetrafluoroethylene (ePTFE) <span class="hlt">conduits</span> with a fan-shaped valve and bulging sinuses for RVOT reconstruction. This retrospective review examined 303 patients who underwent RVOT reconstruction with ePTFE <span class="hlt">conduits</span> at 63 Japanese hospitals between 2003 and 2014. Inclusion criteria were a <span class="hlt">conduit</span> size less than or equal to 16 mm and the use of operative treatment as the primary correction for underlying heart disease. Patients undergoing palliative procedures were excluded. Median follow-up was 1.7 years. Freedom from <span class="hlt">conduit</span> replacement and freedom from <span class="hlt">conduit</span> reintervention were 90.1% ± 4.8% and 77.2% ± 5.6%, respectively. The most common indication for <span class="hlt">conduit</span> reintervention was pulmonary artery (PA) bifurcation stenosis (82%). Modeling z-scores as a dichotomous variable revealed that freedom from <span class="hlt">conduit</span> reintervention for PA bifurcation stenosis was significantly decreased for <span class="hlt">conduits</span> with a z-score greater than or equal to 1.4 compared with z-scores less than 1.4 (p = 0.036). There were 30 patients (9.9%) who experienced at least moderate <span class="hlt">conduit</span> stenosis and 21 patients (6.9%) with at least moderate <span class="hlt">conduit</span> insufficiency. Univariate Cox regression analysis showed that <span class="hlt">conduit</span> size was a significant factor for <span class="hlt">conduit</span> stenosis (p = 0.006). Excellent midterm outcomes were achieved with ePTFE valved <span class="hlt">conduits</span>, even when using smaller sizes. <span class="hlt">Conduit</span> z-scores around 1.4 were optimal for RVOT reconstruction in younger patients. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17429831','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17429831"><span>In vivo evaluation of a biodegradable EDC/NHS-cross-linked gelatin peripheral nerve guide <span class="hlt">conduit</span> material.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chang, Ju-Ying; Lin, Jia-Horng; Yao, Chun-Hsu; Chen, Jiunn-Horng; Lai, Tung-Yuan; Chen, Yueh-Sheng</p> <p>2007-04-10</p> <p>Peripheral nerve regeneration has been evaluated using a biodegradable nerve <span class="hlt">conduit</span>, which is made of a 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC)/N-hydroxysuccinimide (NHS) cross-linked gelatin. The EDC/NHS crosslinked gelatin (ENG) <span class="hlt">conduit</span> is brownish in appearance, and is concentric and round with a smooth outer surface and inner lumen. After subcutaneous implantation on the dorsal side of a rat, the degraded ENG <span class="hlt">conduit</span> only evoked a mild tissue response, with the formation of a thin tissue capsule surrounding the <span class="hlt">conduit</span>. Biodegradability of the ENG <span class="hlt">conduit</span> and its effectiveness as a guidance channel has been examined by its use to repair a 10 mm gap in the rat sciatic nerve. As a result, the tubes degraded throughout the implantation period, but still remained circular with a thin round lumen until they were completely integrated with the enclosed nerves. Successful regeneration through the gap occurred in all the <span class="hlt">conduits</span> over the three experimental periods of 4, 8, and 12 weeks. Histological observation showed that numerous myelinated axons had crossed through the gap region even at the shortest implantation period of 4 weeks. Peak amplitude, area under the muscle action potential curve, and nerve conductive velocity all showed an increase as a function of the recovery period, which indicates that the nerve had undergone adequate regeneration. These results indicate the superiority of the ENG materials and suggest that the novel ENG <span class="hlt">conduits</span> provide a promising tool for neuro-regeneration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26736254','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26736254"><span>Effect of valsalva in the pulmonary prosthetic <span class="hlt">conduit</span> valve on hemodynamic function in a mock circulatory system.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tsuboko, Yusuke; Shiraishi, Yasuyuki; Yamada, Akihiro; Yambe, Tomoyuki; Matsuo, Satoshi; Saiki, Yoshikatsu; Yamagishi, Masaaki</p> <p>2015-01-01</p> <p>Pulmonary <span class="hlt">conduit</span> valves are used as one of the surgical treatment methods of congenital heart diseases. We have been designing a sophisticated pulmonary <span class="hlt">conduit</span> valve for the right ventricular outflow tract reconstruction in pediatric patients. In this study, two types of polyester grafts with or without bulging structures for the <span class="hlt">conduit</span> valves were used and evaluated from the hemodynamic point of view focusing on the application of these <span class="hlt">conduit</span> valves in the grown-up congenital heart failure patients. We examined valvular function in the originally developed pulmonary mock circulatory system, which consisted of a pneumatic driven right ventricular model, a pulmonary valve chamber, and an elastic pulmonary compliance model with peripheral vascular resistance units. Prior to the measurement, a bileaflet valve was sutured in each <span class="hlt">conduit</span>. Each <span class="hlt">conduit</span> valve was installed in the mock right ventricular outflow portion, and its leaflet motion was obtained by using a high-speed camera synchronously with pressure and flow waveforms. As a result, we could obtain hemodynamic changes in two different types of <span class="hlt">conduits</span> for pulmonary valves, and it was indicated that the presence of the Valsalva shape might be effective for promoting valvular response in the low cardiac output condition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70034268','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70034268"><span>Challenges of using electrical resistivity method to locate karst <span class="hlt">conduits</span>-A field case in the Inner Bluegrass Region, Kentucky</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Zhu, J.; Currens, J.C.; Dinger, J.S.</p> <p>2011-01-01</p> <p><span class="hlt">Conduits</span> serve as major pathways for groundwater flow in karst aquifers. Locating them from the surface, however, is one of the most challenging tasks in karst research. Geophysical methods are often deployed to help locate voids by mapping variations of physical properties of the subsurface. <span class="hlt">Conduits</span> can cause significant contrasts of some physical properties that can be detected; other subsurface features such as water-bearing fractures often yield similar contrasts, which are difficult to distinguish from the effects of the <span class="hlt">conduits</span>. This study used electrical resistivity method to search for an unmapped karst <span class="hlt">conduit</span> that recharges Royal Spring in the Inner Bluegrass karst region, Kentucky, USA. Three types of resistivity techniques (surface 2D survey, quasi-3D survey, and time-lapse survey) were used to map and characterize resistivity anomalies. Some of the major anomalies were selected as drilling targets to verify the existence of the <span class="hlt">conduits</span>. Drilling near an anomaly identified by an electrical resistivity profile resulted in successful penetration of a major water-filled <span class="hlt">conduit</span>. The drilling results also suggest that, in this study area, low resistivity anomalies in general are associated with water-bearing features. However, differences in the anomaly signals between the water-filled <span class="hlt">conduit</span> and other water-bearing features such as water-filled fracture zones were undistinguishable. The electrical resistivity method is useful in <span class="hlt">conduit</span> detection by providing potential drilling targets. Knowledge of geology and hydrogeology about the site and professional judgment also played important roles in locating the major <span class="hlt">conduit</span>. ?? 2011 Elsevier B.V.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21397226','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21397226"><span>Large-area irradiated low-level laser effect in a biodegradable nerve guide <span class="hlt">conduit</span> on neural regeneration of peripheral nerve injury in rats.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shen, Chiung-Chyi; Yang, Yi-Chin; Liu, Bai-Shuan</p> <p>2011-08-01</p> <p>This study used a biodegradable composite containing genipin-cross-linked gelatin annexed with β-tricalcium phosphate ceramic particles (genipin-gelatin-tricalcium phosphate, GGT), developed in a previous study, as a nerve guide <span class="hlt">conduit</span>. The aim of this study was to analyse the influence of a large-area irradiated aluminium-gallium-indium phosphide (AlGaInP) diode laser (660 nm) on the neural regeneration of the transected sciatic nerve after bridging the GGT nerve guide <span class="hlt">conduit</span> in rats. The animals were divided into two groups: group 1 comprised sham-irradiated <span class="hlt">controls</span> and group 2 rats underwent low-level laser (LLL) therapy. A compact multi-cluster laser system with 20 AlGaInP laser diodes (output power, 50mW) was applied transcutaneously to the injured peripheral nerve immediately after closing the wound, which was repeated daily for 5 min for 21 consecutive days. Eight weeks after implantation, walking track analysis showed a significantly higher sciatic function index (SFI) score (P<0.05) and better toe spreading development in the laser-treated group than in the sham-irradiated <span class="hlt">control</span> group. For electrophysiological measurement, both the mean peak amplitude and nerve conduction velocity of compound muscle action potentials (CMAPs) were higher in the laser-treated group than in the sham-irradiated group. The two groups were found to be significantly different during the experimental period (P<0.005). Histomorphometric assessments revealed that the qualitative observation and quantitative analysis of the regenerated nerve tissue in the laser-treated group were superior to those of the sham-irradiated group. Thus, the motor functional, electrophysiologic and histomorphometric assessments demonstrate that LLL therapy can accelerate neural repair of the corresponding transected peripheral nerve after bridging the GGT nerve guide <span class="hlt">conduit</span> in rats.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.4287J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.4287J"><span>Shallow <span class="hlt">conduit</span> processes during the 1158 AD explosive eruption of Hekla volcano, Iceland</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Janebo, Maria; Houghton, Bruce; Thordarson, Thor; Larsen, Gudrun</p> <p>2015-04-01</p> <p>Hekla is one of the most frequently active silicic volcanic systems in the world, with multiple pre-historic large Plinian eruptions and 18 historical subplinian-Plinian eruptions. The common view is that the Plinian phases of the largest Hekla eruptions are all relatively homogeneous in style. Of the historical eruptions, only two were silicic: a Plinian eruption in 1104 and a smaller, less well characterized, eruption in 1158. We examine the dynamics of the 1158 eruption in detail with focus on the modulating role of shallow <span class="hlt">conduit</span> processes. Grain size analysis, componentry, and density were used to characterize gradual and abrupt changes during the course of the eruption and quantitative vesicularity analysis was used to constrain the influence of bubble nucleation and coalescence. The 1158 eruption was a relatively steady, dry eruption with a more powerful opening phase followed by a lower intensity, waning phase accompanied by destabilization and collapse of the <span class="hlt">conduit</span> walls. The juvenile pyroclasts are comprised of three types of microvesicular ragged pumice: white, grey, and banded. The abundance of grey pumice decreases as the eruption reaches maximum intensity, and then increases again during the waning phase of the eruption. The white pumices are more vesicular than the grey pumice, and the banded pumices have vesicularities that span predictably the range of the two end-members. The macroscopic differences between the white and grey pumice are accompanied by differences on a microscopic scale, most notably in a decrease in vesicle number density (VND) and a broadening of the vesicle size distribution, as well as increased crystal content. VND values of 0.5 to 1 E+6 mm-3 are similar to those recorded for the more powerful and sustained Plinian phases of the Novarupta 1912 and Taupo 181 eruptions in our laboratory. The 1158 pumice clasts display complex textures with adjacent domains of contrasting texture, alluding to complex nucleation, growth and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23636519','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23636519"><span>Total laparoscopic esophageal bypass using a colonic <span class="hlt">conduit</span> for corrosive-induced esophageal stricture.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Javed, Amit; Agarwal, Anil K</p> <p>2013-10-01</p> <p>The colon and the stomach are the most commonly used <span class="hlt">conduits</span> for esophageal replacement in patients with esophageal strictures resulting from corrosive ingestion. The replacement surgeries have traditionally been performed by an open approach. While laparoscopic replacement surgery using a stomach <span class="hlt">conduit</span> has been previously reported, a total laparoscopic bypass using a colonic <span class="hlt">conduit</span> has not been previously described. We herein describe the surgical technique and results of laparoscopic esophageal bypass using a colonic <span class="hlt">conduit</span>. Patients with corrosive stricture involving the esophagus with the proximal level at the hypopharynx, or those with concomitant gastric scarring, were selected. The surgery was performed with the patient in a supine position using five abdominal ports and a hockey stick/transverse skin crease neck incision. The main steps include colonic mobilization and assessment of the adequacy of the marginal vascular arcade, creation of a retrosternal tunnel, preparation of the colonic <span class="hlt">conduit</span>, neck dissection, delivery of the colonic <span class="hlt">conduit</span> into the neck and cervical pharyngo/esophagocolic anastomosis, and intra-abdominal cologastric and ileocolic anastomosis. During the study period, 39 patients with corrosive stricture of the esophagus were managed surgically at our center with either gastric or colonic bypass. Of these, 22 patients underwent an open procedure (12 retrosternal colonic bypasses and 10 retrosternal gastric bypasses) and 17 patients underwent a laparoscopic procedure (13 retrosternal gastric bypasses and 4 retrosternal colonic bypasses). Patients with stricture at the hypopharynx (n = 2) or those in whom the stomach was contracted (n = 2) were considered for a laparoscopic esophagocoloplasty. The average duration of surgery of these latter four patients was 370 (380, 320, 360, and 420) min and the mean estimated blood loss was 100 mL. All patients could be ambulated on the first postoperative day and were allowed oral liquids</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24529058','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24529058"><span>Retrograde exchange of heavily encrusted ureteric stents via the ileal <span class="hlt">conduit</span>: a technical report.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tapping, Charles Ross; Boardman, Phil</p> <p>2014-02-01</p> <p>We describe two cases of retrograde ureteric stent exchange of heavily encrusted ureteric stents (JJ) via tortuous ileal <span class="hlt">conduits</span>. The blocked ureteric stents were snared from inside the <span class="hlt">conduit</span> so they could be accessed and a wire inserted. The lumens of the stents were unblocked with a wire but the stents could not be withdrawn due to heavy encrustation of the ureteric stent in the renal pelvis. A stiff wire was inserted to provide support and a 9 French peel away sheath was used to remove the encrustations allowing the stents to be withdrawn and exchanged. This is a safe and successful technique allowing ureteric stents to be removed when heavily encrusted. © 2013 The Royal Australian and New Zealand College of Radiologists.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28485400','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28485400"><span>Actively evolving subglacial <span class="hlt">conduits</span> and eskers initiate ice shelf channels at an Antarctic grounding line.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Drews, R; Pattyn, F; Hewitt, I J; Ng, F S L; Berger, S; Matsuoka, K; Helm, V; Bergeot, N; Favier, L; Neckel, N</p> <p>2017-05-09</p> <p>Ice-shelf channels are long curvilinear tracts of thin ice found on Antarctic ice shelves. Many of them originate near the grounding line, but their formation mechanisms remain poorly understood. Here we use ice-penetrating radar data from Roi Baudouin Ice Shelf, East Antarctica, to infer that the morphology of several ice-shelf channels is seeded upstream of the grounding line by large basal obstacles indenting the ice from below. We interpret each obstacle as an esker ridge formed from sediments deposited by subglacial water <span class="hlt">conduits</span>, and calculate that the eskers' size grows towards the grounding line where deposition rates are maximum. Relict features on the shelf indicate that these linked systems of subglacial <span class="hlt">conduits</span> and ice-shelf channels have been changing over the past few centuries. Because ice-shelf channels are loci where intense melting occurs to thin an ice shelf, these findings expose a novel link between subglacial drainage, sedimentation and ice-shelf stability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/135133','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/135133"><span>TPX superconducting cable-in-<span class="hlt">conduit</span> 1995 design and development progress</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zbasnik, J.P.; Martovetsky, N.N.; Hibbs, S.M.</p> <p>1995-09-29</p> <p>A unique feature of the magnet system for the Tokamak Physics Experiment (TPX) is that all the magnets are superconducting. With the exception of the outer poloidal coils, the magnet system uses Nb{sub 3}Sn cable-in-<span class="hlt">conduit</span> conductor; the outer poloidal coils use Nb-Ti cable-in-<span class="hlt">conduit</span> conductor. We describe the current TPX conductor design and present a progress report on the conductor development. Our strand development contracts have resulted in demonstrating that at least two vendors can produce Nb{sub 3}Sn strand which meets the TPX specification. Subcable testing gives confidence that the TPX conductor will satisfy the magnet operational requirements. Fabrication of full-size conductors is underway and tests on these will give verification that the TPX conductor meets the operational requirements. Our industrial cabling and sheathing contract to produce demonstration conductor using copper strands is exploring a production technique that differs from the conventional tube mill approach.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997Cryo...37..431V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997Cryo...37..431V"><span>Measurements of current distribution in a 12-strand Nb 3Sn cable-in-<span class="hlt">conduit</span> conductor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vysotsky, Vitaly S.; Takayasu, Makoto; Jeong, Sangkwon; Michael, Philip C.; Schultz, Joel H.; Minervini, Joseph V.</p> <p></p> <p>Experiments were performed to measure directly the current in each strand of a 12-strand Nb 3Sn cable-in-<span class="hlt">conduit</span> superconductor during current and/or external magnetic field ramps. The goal of the experiment was to get straightforward evidence of current maldistribution in a cable-in-<span class="hlt">conduit</span> conductor (CICC). A heavily instrumented sample coil from Nb 3Sn TPX-TF strands was specially prepared. Severe non-uniformity of the strand currents were found during field ramp. Immediately before a quench the individual strand currents within a triplet differed by as much as an order of magnitude. During field ramps with constant transport current, the currents in some strands were observed to drop rapidly and then recover. The data show that quench development in the CICC is a complicated phenomenon involving dynamic redistribution of current among the strands. Non-uniformity of current along the strands during quench was also observed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70029951','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70029951"><span>Three-dimensional structure of fluid <span class="hlt">conduits</span> sustaining an active deep marine cold seep</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hornbach, M.J.; Ruppel, C.; Van Dover, C.L.</p> <p>2007-01-01</p> <p>Cold seeps in deep marine settings emit fluids to the overlying ocean and are often associated with such seafloor flux indicators as chemosynthetic biota, pockmarks, and authigenic carbonate rocks. Despite evidence for spatiotemporal variability in the rate, locus, and composition of cold seep fluid emissions, the shallow subseafloor plumbing systems have never been clearly imaged in three dimensions. Using a novel, high-resolution approach, we produce the first three-dimensional image of possible fluid <span class="hlt">conduits</span> beneath a cold seep at a study site within the Blake Ridge gas hydrate province. Complex, dendritic features diverge upward toward the seafloor from feeder <span class="hlt">conduits</span> at depth and could potentially draw flow laterally by up to 103 m from the known seafloor seep, a pattern similar to that suggested for some hydrothermal vents. The biodiversity, community structure, and succession dynamics of chemosynthetic communities at cold seeps may largely reflect these complexities of subseafloor fluid flow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NatCo...815228D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NatCo...815228D"><span>Actively evolving subglacial <span class="hlt">conduits</span> and eskers initiate ice shelf channels at an Antarctic grounding line</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Drews, R.; Pattyn, F.; Hewitt, I. J.; Ng, F. S. L.; Berger, S.; Matsuoka, K.; Helm, V.; Bergeot, N.; Favier, L.; Neckel, N.</p> <p>2017-05-01</p> <p>Ice-shelf channels are long curvilinear tracts of thin ice found on Antarctic ice shelves. Many of them originate near the grounding line, but their formation mechanisms remain poorly understood. Here we use ice-penetrating radar data from Roi Baudouin Ice Shelf, East Antarctica, to infer that the morphology of several ice-shelf channels is seeded upstream of the grounding line by large basal obstacles indenting the ice from below. We interpret each obstacle as an esker ridge formed from sediments deposited by subglacial water <span class="hlt">conduits</span>, and calculate that the eskers' size grows towards the grounding line where deposition rates are maximum. Relict features on the shelf indicate that these linked systems of subglacial <span class="hlt">conduits</span> and ice-shelf channels have been changing over the past few centuries. Because ice-shelf channels are loci where intense melting occurs to thin an ice shelf, these findings expose a novel link between subglacial drainage, sedimentation and ice-shelf stability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17803551','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17803551"><span>Computed tomography arteriography to assess greater saphenous vein as a <span class="hlt">conduit</span> for peripheral bypass.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kang, Alan; Buckenham, Timothy; Roake, Justin; Lewis, David</p> <p>2007-10-01</p> <p>To determine whether computed tomography arteriography of the lower extremities (64-slice volume computed tomography (CT)), used in delineating the arterial tree in peripheral vascular disease, is useful in assessing suitability of greater saphenous vein as a vascular <span class="hlt">conduit</span> for peripheral bypass grafting for limb-threatening lower limb ischaemia. A search of published works in August 2005 showed no similar study has been published. A prospective study of nine consecutive patients who had undergone lower limb CT arteriography and long saphenous vein colour duplex ultrasound (U/S) were studied. Good concordance between colour duplex U/S and CT arteriography was obtained. Computed tomography images of the long saphenous vein as a part of arterial lower limb CT arteriography correlate well with preoperative <span class="hlt">conduit</span> assessment colour duplex U/S findings of the long saphenous vein.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GeoRL..41.8342S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GeoRL..41.8342S"><span>Crab burrows as <span class="hlt">conduits</span> for groundwater-surface water exchange in Bangladesh</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stahl, Mason O.; Tarek, M. H.; Yeo, Darren C. J.; Badruzzaman, A. B. M.; Harvey, Charles F.</p> <p>2014-12-01</p> <p>Groundwater recharge affects water budgets and groundwater quality on the deltas and floodplains of South and Southeast Asia. Rain and flooding rivers recharge groundwater during the monsoon; irrigated rice fields and surface water bodies recharge aquifers during the dry season. Groundwater throughout the region is severely contaminated by arsenic, and recent research suggests that quantifying and characterizing recharge is important to understand whether recharge flushes or mobilizes arsenic from aquifers. At a field site in Bangladesh, we found that burrows of terrestrial crabs short-circuit low-permeability surface sediments, providing the primary <span class="hlt">conduit</span> for recharge. We combine field observations along with a model that couples isotope and water balances to quantify the effect of crab burrows on aquifer recharge. Given the wide distribution of burrowing crabs and the surficial geology, we suggest that crab burrows provide widespread <span class="hlt">conduits</span> for groundwater recharge.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/7182522','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/7182522"><span>Fluid dynamics of supercritical hellium within cable-in-<span class="hlt">conduit</span> conductors</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Van Sciver, S.W.</p> <p>1992-07-01</p> <p>The enclosed report summarizes work carried out under DOE/MFE Support, during the past four years. Emphasis is placed on progress within the last year. Results of experiments on pressure drop and heat transfer within several Cable-in-<span class="hlt">Conduit</span> Conductors are described. These results are compared to models for flow in similar geometrics. The work provides a basis for design of magnets using the CIC Conductor Concept.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10169848','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10169848"><span>Fluid dynamics of supercritical hellium within cable-in-<span class="hlt">conduit</span> conductors. Progress report</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Van Sciver, S.W.</p> <p>1992-07-01</p> <p>The enclosed report summarizes work carried out under DOE/MFE Support, during the past four years. Emphasis is placed on progress within the last year. Results of experiments on pressure drop and heat transfer within several Cable-in-<span class="hlt">Conduit</span> Conductors are described. These results are compared to models for flow in similar geometrics. The work provides a basis for design of magnets using the CIC Conductor Concept.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70035290','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70035290"><span>CO2 outgassing in a combined fracture and <span class="hlt">conduit</span> karst aquifer near lititz spring, Pennsylvania</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Toran, L.; Roman, E.</p> <p>2006-01-01</p> <p>Lititz Spring in southeastern Pennsylvania and a nearby domestic well were sampled for 9 months. Although both locations are connected to <span class="hlt">conduits</span> (as evidenced by a tracer test), most of the year they were saturated with respect to calcite, which is more typical of matrix flow. Geochemical modeling (PHREEQC) was used to explain this apparent paradox and to infer changes in matrix and <span class="hlt">conduit</span> contribution to flow. The saturation index varied from 0.5 to 0 most of the year, with a few samples in springtime dropping below saturation. The log PCO2 value varied from -2.5 to -1.7. Lower log PCO2 values (closer to the atmospheric value of -3.5) were observed when the solutions were at or above saturation with respect to calcite. In contrast, samples collected in the springtime had high PCO2, low saturation indices, and high water levels. Geochemical modeling showed that when outgassing occurs from a water with initially high PCO2, the saturation index of calcite increases. In the Lititz Spring area, the recharge water travels through the soil zone, where it picks up CO2 from soil gas, and excess CO 2 subsequently is outgassed when this recharge water reaches the <span class="hlt">conduit</span>. At times of high water level (pipe full), recharge with excess CO 2 enters the system but the outgassing does not occur. Instead the recharge causes dilution, reducing the calcite saturation index. Understanding the temporal and spatial variation in matrix and <span class="hlt">conduit</span> flow in karst aquifers benefited here by geochemical modeling and calculation of PCO2 values. ?? 2006 Geological Society of America.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16211569','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16211569"><span>An in vivo study of tricalcium phosphate and glutaraldehyde crosslinking gelatin <span class="hlt">conduits</span> in peripheral nerve repair.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Ming-Hong; Chen, Pei-Ru; Chen, Mei-Hsiu; Hsieh, Sung-Tsang; Huang, Jing-Shan; Lin, Feng-Huei</p> <p>2006-04-01</p> <p>In order to modulate the mechanical properties of gelatin, we previously developed a biodegradable composite composed by tricalcium phosphate and glutaraldehyde crosslinking gelatin (GTG) feasible for surgical manipulation. In this study, we evaluated the in vivo applications of GTG <span class="hlt">conduit</span> for peripheral nerve repair. The effect of sciatic nerve reconstruction was compared between resorbable permeable GTG <span class="hlt">conduits</span> and durable impermeable silicone tubes. Traditional methods of assessing nerve recovery following peripheral nerve repair including histomorphometric and electrophysiologic features were conducted in our study. In addition, autotomy score and sciatic function index (SFI) in walking tract analysis were used as additional parameters for assessing the return of nerve function. Twenty-four weeks after sciatic nerve repair, the GTG <span class="hlt">conduits</span> were harvested. Microscopically, regeneration of nerves was observed in the cross-section at the mid portion of all implanted GTG <span class="hlt">conduits</span>. The cross-sectional area of regenerated nerve of the GTG group was significant larger than that of the silicone group. In the compound muscle action potentials (CMAP), the mean recovery index of CMAP amplitude was 0.24 +/- 0.02 for the silicone group, 0.41 +/- 0.07 for the GTG group. The mean SFI increased with time in the GTG group during the evaluation period until 24 weeks. Walking tract analysis showed a higher SFI score in the GTG group at both 12 and 24 weeks. The difference reached a significant level at 24 weeks. Thus, the histomorphometric, electrophysiologic, and functional assessments demonstrate that GTG can be a candidate for peripheral nerve repair.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.9631C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.9631C"><span>Physical mechanisms that lead to large-scale gas accumulation in a volcanic <span class="hlt">conduit</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Collombet, Marielle; Burgisser, Alain</p> <p>2016-04-01</p> <p>The eruption of viscous magma at the Earth's surface often gives rise to abrupt regime changes. The transition from the gentle effusion of a lava dome to brief but powerful explosions is a common regime change. This transition is often preceded by the sealing of the shallow part of the volcanic <span class="hlt">conduit</span> and the accumulation of volatile-rich magma underneath, a situation that collects the energy to be brutally released during the subsequent explosion. While <span class="hlt">conduit</span> sealing is well-documented, volatile accumulation has proven harder to characterize. We use a 2D <span class="hlt">conduit</span> flow model including gas loss within the magma and into the wallrock to find steady-state magma flow configurations in the effusive regime. Model outputs yield a strongly heterogeneous distribution of the gas volume fraction underneath a dense, impermeable magma cap. Gas accumulates in inclined structures hundredths of meters long and several meters thick. These structures probably constitute the gas pockets that accumulate explosive energy and that were intuited by previous studies. We tested the numerical robustness of our results by simulating the fragmented state of the magma contained within the pockets, by testing various fragmentation criteria, and by varying computational gird size. These gas pockets are robust features that occur regardless of wallrock permeability (from very permeable at 10-12 m2 to quasi impermeable at 10-16 m2) but that are sensitive to the volume to surface ratio of the volcanic <span class="hlt">conduit</span>. One implication is that the formation of these large degassing structures probably plays an essential role in the triggering of violent explosions. Such large scale outgassing feature may also bring a partial answer to the long standing issue of the observed gas transfer across entire magmatic systems despite high magma viscosity and no obvious physical mechanism of transfer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1910595M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1910595M"><span>Experimental and numerical analysis of fluid flow in pipe - like <span class="hlt">conduits</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mendo-Pérez, Gerardo M.; Arciniega-Ceballos, Alejandra; Guzmán-Vázquez, José E.; Sánchez-Sesma, Francisco J.</p> <p>2017-04-01</p> <p>Volcanic activity is complex and it is a good example of multiscale phenomenon due to the sundry processes that occur at different scales while fluids ascend from the magmatic reservoirs to volcanic vents. Several processes occur at their own time scale and within a wide range of strengths. Each process contributes with its particular elastic response to the overall stress-strain field of the <span class="hlt">conduit</span> dynamics. In this work, we present experimental and numerical analysis of fluid flowing through pipe-like <span class="hlt">conduits</span> in order to understand the dynamic of the volcanic eruptions and its effects on the seismic signals. We focused on the elastic response of cylindrical <span class="hlt">conduits</span> due to the flow of viscous Newtonian fluids (0.001 and 1 Pa s) passing through them. We compared signals obtained experimentally with those calculated by numerical modeling. The experimental signals are recorded with high dynamic range piezoelectric sensors located along the <span class="hlt">conduit</span> where the fluid flows due to a sudden pressure drop. The numerical counterparts are calculated through a scheme that involves the continuity and motion equations for fluids, where the fluid couples with the surrounding solid; the excitation function simulates a pressure drop, in the range of the experimental values. In both, the excitation is considered an instantaneous pressure drop from maximum 3 bar to ambient pressure. The analysis of these observations included video recording of the process with a high speed camera. The dynamic behavior of experimental and numerical simulations present high similarity with field volcanic signals associated with pressurization processes. Our studies contributes to the understanding volcanic phenomenon and its effects on field base seismograms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016BVol...78...74J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016BVol...78...74J"><span>Shallow <span class="hlt">conduit</span> processes during the ad 1158 explosive eruption of Hekla volcano, Iceland</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Janebo, Maria H.; Houghton, Bruce F.; Thordarson, Thorvaldur; Larsen, Gudrun</p> <p>2016-10-01</p> <p>Hekla is one of the most frequently active felsic volcanic systems in the world, with several known pre-historic large Plinian eruptions and 18 historical subplinian to small Plinian eruptions. A common view is that Plinian eruptions of Hekla are relatively short lived and purely explosive events. In detail, these events exhibit subtle differences in terms of deposit characteristics, reflecting significant differences in eruption behaviour. Of the 18 historical eruptions, two had bulk magma compositions with >66 wt% SiO2: a Plinian eruption in ad 1104 and a smaller, less well characterised, but atypical subplinian eruption in ad 1158. The ad 1158 eruption was a relatively sustained, dry (magmatic) eruption with a more powerful opening phase followed by a lower intensity, waning phase accompanied by minor destabilisation and collapse of the <span class="hlt">conduit</span> walls. We examine here the dynamics of the ad 1158 eruption, focussing on the role of shallow <span class="hlt">conduit</span> processes in modulating eruption dynamics. Vesicularity data constrain the relative influence of bubble nucleation, growth, and coalescence. The juvenile pyroclasts are composed of two types of microvesicular pumice (white and grey) with contrasting vesicle number density, vesicle-size distribution, and phenocryst and microlite contents. Textural analysis shows that these pumices reflect heterogeneity developed pre- to syn-eruptively in the <span class="hlt">conduit</span> and that entrainment of longer resident magma by faster ascending magma permitted magma of contrasting maturity to be fragmented simultaneously. In this regard, the mixed melt of the ad 1158 eruption contrasts with the compositionally homogeneous melt phase of the more powerful ad 1104 Plinian event, which was typified by more uniform <span class="hlt">conduit</span> and eruption dynamics accompanying higher average ascent rates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25394224','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25394224"><span>Possible <span class="hlt">conduit</span>-matrix water exchange signatures outlined at a karst spring.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mitrofan, Horia; Marin, Constantin; Povară, Ioan</p> <p>2015-04-01</p> <p>During a significant flood event, reversible water exchanges may occur between a karst <span class="hlt">conduit</span> and its adjacent porous rock (frequently designated as "matrix"): while the flood pulse rises, some <span class="hlt">conduit</span>-derived water is forced into the matrix; then, as the flood recedes, the same water flows back into the stream passage. The present note addresses such a karst setting in the Carpathian Mountains (Romania), where in addition, a usually stable flux of chloride originating in a natural saline inflow, was being mixed with a variable flow of karst freshwater. For that particular case, with the above-mentioned process of matrix storage/release from storage assumedly taking place downstream of the mixing site, two distinct chemical signatures could be noticed during a flood event: an initial depletion in the spring flow chloride flux, subsequently followed by a comparable chloride flux enrichment (the depletion and the enrichment being outlined with respect to the essentially stable chloride flux value that had been noticed to persist at the spring over a long period of flow rate recession). Concomitantly with such flood-induced fluctuations in the spring chloride flux, the spring discharge displayed, for long periods, abnormally slow variations: the latter likely indicated that the spring supply rate actual oscillations were buffered by the reversible water exchanges which took place between the karst <span class="hlt">conduit</span> and its adjacent matrix. On the whole, these results show that <span class="hlt">conduit</span>-matrix water exchanges could be interpreted by simple mass balance calculations that involved fluxes of a conservative tracer (the chloride ion in that particular case). © 2014, National Ground Water Association.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/78708','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/78708"><span>Final report on fluid dynamics of supercritical helium within cable-in-<span class="hlt">conduit</span> conductors</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Van Sciver, S.W.</p> <p>1992-07-01</p> <p>The enclosed report summarizes work carried out under DOE/MFE support during the past four years. Emphasis is placed on progress during the last year. Results of experiments on pressure drop and heat transfer within several Cable-in-<span class="hlt">Conduit</span> conductors are described. These results are compared to models developed for flow in similar geometries. The work provides a basis for design of magnets using CIC conductors in fusion magnetic systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6090117','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6090117"><span>Pressure drop measurements on cable-in-<span class="hlt">conduit</span> conductors of various geometries</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Daugherty, M.A.; Van Sciver, S.W. . Applied Superconductivity Center)</p> <p>1991-03-01</p> <p>This paper measures the pressure drop on various cable-in-<span class="hlt">conduit</span> conductors with different void fractions, number of strands and flow areas. To carry out these measurements, supercritical helium is circulated through a loop containing several conductor sections instrumented with cold pressure transducers. A cold centrifugal pump is used to force the helium through the loop at flow rates of up to several grams per second. The modular design of the flow loop allows for relatively easy insertion of different test sections.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5177999','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5177999"><span>Surgical Clips Migration up to Renal Collecting System from Ileal <span class="hlt">Conduit</span> Postcystectomy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Albadawi, Hani; Sener, Tarik Emre</p> <p>2016-01-01</p> <p>Abstract This is a 49-year-old female known to have had cystectomy and ileal <span class="hlt">conduit</span> 4 years ago presented to our hospital complaining of left flank pain with recurrent urinary tract infection. Radiologic investigations showed left lower pole renal stone. She underwent left laser flexible ureterorenoscopy. Renal collection system was fully explored that showed stone occupying the lower calix, laser disintegration of the stone revealed what we assumed are surgical clips. PMID:28078327</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17560237','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17560237"><span>Use of autogenous saphenous vein as a <span class="hlt">conduit</span> for mesenterico-left portal vein bypass.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Query, Julie A; Sandler, Anthony D; Sharp, William J</p> <p>2007-06-01</p> <p>The authors describe a case of extrahepatic portal vein (EHPV) thrombosis and portal hypertension treated with a variant of mesenterico-left portal vein bypass (MLPVB) or Rex shunt. In this case, a segment of autogenous greater saphenous vein was used to bridge the distance between the left gastric vein inflow and the left portal vein. Use of such nontraditional <span class="hlt">conduit</span> in similar circumstances may expand the application of portal revascularization/decompression procedures in treating these patients.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18440619','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18440619"><span>Sciatic nerve repair by microgrooved nerve <span class="hlt">conduits</span> made of chitosan-gold nanocomposites.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lin, Yi-Lo; Jen, Jui-Chi; Hsu, Shan-hui; Chiu, Ing-Ming</p> <p>2008-12-01</p> <p>To better direct the repair of peripheral nerve after injury, an implant consisting of a multicomponent micropatterned <span class="hlt">conduit</span> seeded with NSC was designed. The mechanical properties of the chi-Au nanocomposites were tested. In vitro, the effect of chi-Au on cell behavior (NSC and glial cell line C6) and the influence of micropattern on cell alignment were evaluated. In vivo, the micropatterned <span class="hlt">conduits</span> with/without the preseeded NSC were implanted to bridge a 10-mm-long defect of the sciatic nerve in 9 male Sprague-Dawley rats. The repair outcome was investigated 6 weeks after the surgery. Based on the dynamic modulus, chitosan with 50 ppm or more gold was a stronger material than others. In vitro, gold at 25 or 50 ppm led to better cell performance for NSC; and gold at 50 ppm gave better cell performance for C6. On the microgrooved substrate, the NSC had elongated processes oriented parallel to the grooves, whereas the NSC on the nonpatterned surfaces did not exhibit a particular bias in alignment. In vivo, the number of regenerated axons, the regenerated area, and the number of blood vessels were significantly higher in the NSC-preseeded <span class="hlt">conduit</span>. Modification of the chitosan matrix by gold nanoparticles not only provides the mechanical strength but also affects the cellular response. The preliminary in vivo data demonstrated that the biodegradable micropatterned <span class="hlt">conduits</span> preseeded with NSC provided a combination of physical and biological guidance cues for regenerating axons at the cellular level and offered a better alternative for repairing sciatic nerve transactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21779553','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21779553"><span>Magnetic domain wall <span class="hlt">conduits</span> for single cell applications.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Donolato, M; Torti, A; Kostesha, N; Deryabina, M; Sogne, E; Vavassori, P; Hansen, M F; Bertacco, R</p> <p>2011-09-07</p> <p>The ability to trap, manipulate and release single cells on a surface is important both for fundamental studies of cellular processes and for the development of novel lab-on-chip miniaturized tools for biological and medical applications. In this paper we demonstrate how magnetic domain walls generated in micro- and nano-structures fabricated on a chip surface can be used to handle single yeast cells labeled with magnetic beads. In detail, first we show that the proposed approach maintains the microorganism viable, as proven by monitoring the division of labeled yeast cells trapped by domain walls over 16 hours. Moreover, we demonstrate the <span class="hlt">controlled</span> transport and release of individual yeast cells via displacement and annihilation of individual domain walls in micro- and nano-sized magnetic structures. These results pave the way to the implementation of magnetic devices based on domain walls technology in lab-on-chip systems devoted to accurate individual cell trapping and manipulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27775616','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27775616"><span>Natural Occurring Silks and Their Analogues as Materials for Nerve <span class="hlt">Conduits</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Radtke, Christine</p> <p>2016-10-20</p> <p>Spider silk and its synthetic derivatives have a light weight in combination with good strength and elasticity. Their high cytocompatibility and low immunogenicity make them well suited for biomaterial products such as nerve <span class="hlt">conduits</span>. Silk proteins slowly degrade enzymatically in vivo, thus allowing for an initial therapeutic effect such as in nerve scaffolding to facilitate endogenous repair processes, and then are removed. Silks are biopolymers naturally produced by many species of arthropods including spiders, caterpillars and mites. The silk fibers are secreted by the labial gland of the larvae of some orders of Holometabola (insects with pupa) or the spinnerets of spiders. The majority of studies using silks for biomedical applications use materials from silkworms or spiders, mostly of the genus Nephila clavipes. Silk is one of the most promising biomaterials with effects not only in nerve regeneration, but in a number of regenerative applications. The development of silks for human biomedical applications is of high scientific and clinical interest. Biomaterials in use for biomedical applications have to meet a number of requirements such as biocompatibility and elicitation of no more than a minor inflammatory response, biodegradability in a reasonable time and specific structural properties. Here we present the current status in the field of silk-based <span class="hlt">conduit</span> development for nerve repair and discuss current advances with regard to potential clinical transfer of an implantable nerve <span class="hlt">conduit</span> for enhancement of nerve regeneration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4997342','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4997342"><span>Long distance seawater intrusion through a karst <span class="hlt">conduit</span> network in the Woodville Karst Plain, Florida</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Xu, Zexuan; Bassett, Seth Willis; Hu, Bill; Dyer, Scott Barrett</p> <p>2016-01-01</p> <p>Five periods of increased electrical conductivity have been found in the karst <span class="hlt">conduits</span> supplying one of the largest first magnitude springs in Florida with water. Numerous well-developed <span class="hlt">conduit</span> networks are distributed in the Woodville Karst Plain (WKP), Florida and connected to the Gulf of Mexico. A composite analysis of precipitation and electrical conductivity data provides strong evidence that the increases in conductivity are directly tied to seawater intrusion moving inland and traveling 11 miles against the prevailing regional hydraulic gradient from from Spring Creek Spring Complex (SCSC), a group of submarine springs at the Gulf Coast. A geochemical analysis of samples from the spring vent rules out anthropogenic contamination and upwelling regional recharge from the deep aquifer as sources of the rising conductivity. The interpretation is supported by the conceptual model established by prior researchers working to characterize the study area. This paper documents the first and longest case of seawater intrusion in the WKP, and also indicates significant possibility of seawater contamination through subsurface <span class="hlt">conduit</span> networks in a coastal karst aquifer. PMID:27557803</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27865067','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27865067"><span>Laminin-modified and aligned PHBV/PEO nanofibrous nerve <span class="hlt">conduits</span> promote peripheral nerve regeneration.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Xiao-Feng; Liu, Hai-Xia; Ortiz, Lazarus Santiago; Xiao, Zhong-Dang; Huang, Ning-Ping</p> <p>2016-11-12</p> <p>Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) has received much attention for its biodegradability and biocompatibility, characteristics which are required in tissue engineering. In this study, polyethylene oxide (PEO)-incorporated PHBV nanofibers with random or aligned orientation were obtained by electrospinning. For further use in vivo, the nanofiber films were made into nerve <span class="hlt">conduits</span> after treated with NH3 plasma, which could improve the hydrophilicity of inner surfaces of nerve <span class="hlt">conduits</span> and then facilitate laminin adsorption via electrostatic interaction for promoting cell adhesion and proliferation. Morphology of the surfaces of modified PHBV/PEO nanofibrous scaffolds were examined by scanning electron microscopy. Schwann cell viability assay was conducted and the results confirmed that the functionalized nanofibers were favorable for cell growth. Morphology of Schwann cells cultured on scaffolds showed that aligned nanofibrous scaffolds provided topographical guidance for cell orientation and elongation. Furthermore, 3D PHBV/PEO nerve <span class="hlt">conduits</span> made from aligned and random-oriented nanofibers were implanted into 12-mm transected sciatic nerve rat model and subsequent analysis were conducted at 1 and 2 months post-surgery. The above functionalized PHBV/PEO scaffolds provide a novel and promising platform for peripheral nerve regeneration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5266796','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5266796"><span>Peripheral Nerve Regeneration Strategies: Electrically Stimulating Polymer Based Nerve Growth <span class="hlt">Conduits</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Anderson, Matthew; Shelke, Namdev B.; Manoukian, Ohan S.; Yu, Xiaojun; McCullough, Louise D.; Kumbar, Sangamesh G.</p> <p>2017-01-01</p> <p>Treatment of large peripheral nerve damages ranges from the use of an autologous nerve graft to a synthetic nerve growth <span class="hlt">conduit</span>. Biological grafts, in spite of many merits, show several limitations in terms of availability and donor site morbidity, and outcomes are suboptimal due to fascicle mismatch, scarring, and fibrosis. Tissue engineered nerve graft substitutes utilize polymeric <span class="hlt">conduits</span> in conjunction with cues both chemical and physical, cells alone and or in combination. The chemical and physical cues delivered through polymeric <span class="hlt">conduits</span> play an important role and drive tissue regeneration. Electrical stimulation (ES) has been applied toward the repair and regeneration of various tissues such as muscle, tendon, nerve, and articular tissue both in laboratory and clinical settings. The underlying mechanisms that regulate cellular activities such as cell adhesion, proliferation, cell migration, protein production, and tissue regeneration following ES is not fully understood. Polymeric constructs that can carry the electrical stimulation along the length of the scaffold have been developed and characterized for possible nerve regeneration applications. We discuss the use of electrically conductive polymers and associated cell interaction, biocompatibility, tissue regeneration, and recent basic research for nerve regeneration. In conclusion, a multifunctional combinatorial device comprised of biomaterial, structural, functional, cellular, and molecular aspects may be the best way forward for effective peripheral nerve regeneration. PMID:27278739</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25934451','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25934451"><span>PRGD/PDLLA <span class="hlt">conduit</span> potentiates rat sciatic nerve regeneration and the underlying molecular mechanism.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Binbin; Qiu, Tong; Iyer, K Swaminathan; Yan, Qiongjiao; Yin, Yixia; Xie, Lijuan; Wang, Xinyu; Li, Shipu</p> <p>2015-07-01</p> <p>Peripheral nerve injury requires optimal conditions in both macro-environment and micro-environment for reestablishment. Though various strategies have been carried out to improve the macro-environment, the underlying molecular mechanism of axon regeneration in the micro-environment provided by nerve <span class="hlt">conduit</span> remains unclear. In this study, the rat sciatic nerve of 10 mm defect was made and bridged by PRGD/PDLLA nerve <span class="hlt">conduit</span>. We investigated the process of nerve regeneration using histological, functional and real time PCR analyses after implantation from 7 to 35 days. Our data demonstrated that the ciliary neurotrophic factor highly expressed and up-regulated the downstream signaling pathways, in the case of activated signals, the expressions of axon sprout relative proteins, such as tubulin and growth-associated protein-43, were strongly augmented. Taken together, these data suggest a possible mechanism of axon regeneration promoted by PRGD/PDLLA <span class="hlt">conduit</span>, which created a micro-environment for enhancement of diffusion of neurotrophic factors secreted by the injured nerve stumps, and activation of molecular signal transduction involved in growth cone, to potentiate the nerve recovery.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016BVol...78...63G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016BVol...78...63G"><span><span class="hlt">Conduit</span> enlargement during the precursory Plinian eruption of Aira Caldera, Japan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Geshi, Nobuo; Miyabuchi, Yasuo</p> <p>2016-09-01</p> <p>Increase in magma flux as the result of <span class="hlt">conduit</span> enlargement is one of the key processes that triggered caldera collapse and eruption of the Ito ignimbrite from Aira Caldera at ~29 ka. We examine the total volume of the pumice fall deposit, vertical variations in grain size of pumice, and the lithic content in the Osumi pumice deposit to investigate the trigger for caldera collapse. Wider distribution of the later-stage unit and the upward coarsening of grain size throughout the Osumi pumice fall deposit indicate an increase in magma discharge toward the onset of collapse. The total volume of lithic fragments in the Osumi pumice fall deposit is estimated as ~1.6 km3, based on the lithic content in several representative outcrops and the total volume of the Osumi pumice fall deposit. The lithic fragments in the Osumi pumice fall deposit indicate intense mechanical erosion of the <span class="hlt">conduit</span> during the Plinian eruption prior to caldera collapse. Caldera collapse requires decompression of the magma chamber by withdrawal of magma; effective enlargement of the <span class="hlt">conduit</span> diameter during precursory eruptive phases is one of the important processes that subsequently allow the rapid discharge of a large volume of magma, which in turn facilitates decompression of the reservoir and induces caldera collapse.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27557803','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27557803"><span>Long distance seawater intrusion through a karst <span class="hlt">conduit</span> network in the Woodville Karst Plain, Florida.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xu, Zexuan; Bassett, Seth Willis; Hu, Bill; Dyer, Scott Barrett</p> <p>2016-08-25</p> <p>Five periods of increased electrical conductivity have been found in the karst <span class="hlt">conduits</span> supplying one of the largest first magnitude springs in Florida with water. Numerous well-developed <span class="hlt">conduit</span> networks are distributed in the Woodville Karst Plain (WKP), Florida and connected to the Gulf of Mexico. A composite analysis of precipitation and electrical conductivity data provides strong evidence that the increases in conductivity are directly tied to seawater intrusion moving inland and traveling 11 miles against the prevailing regional hydraulic gradient from from Spring Creek Spring Complex (SCSC), a group of submarine springs at the Gulf Coast. A geochemical analysis of samples from the spring vent rules out anthropogenic contamination and upwelling regional recharge from the deep aquifer as sources of the rising conductivity. The interpretation is supported by the conceptual model established by prior researchers working to characterize the study area. This paper documents the first and longest case of seawater intrusion in the WKP, and also indicates significant possibility of seawater contamination through subsurface <span class="hlt">conduit</span> networks in a coastal karst aquifer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27427674','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27427674"><span>Thermo-Hydraulic Characteristics of Anatase Titania Nanofluids Flowing Through a Circular <span class="hlt">Conduit</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kristiawan, Budi; Kamal, Samsul; Yanuar</p> <p>2016-06-01</p> <p>The thermo-hydraulic characteristics of anatase titanium dioxide dispersed into distilled water with particle concentration of 0.1, 0.3, and 0.5 vol.% were investigated experimentally in this work. The influence of rheological behavior on hydrodynamic and convective heat transfer characteristics was evaluated under both laminar and turbulent flow conditions in a plain <span class="hlt">conduit</span> and with twisted tape insert for twist ratio of 7. The nanofluids exhibited a strong shear-thinning behavior at low shear rate particularly higher particle concentration. The non-Newtonian titania nanofluids have also demonstrated a drag reduction phenomena in turbulent flow. At equal Reynolds number, the values of performance evaluation criterion in a <span class="hlt">conduit</span> inserted a twisted tape were lower than those of in a plain <span class="hlt">conduit</span>. It implies the unfavourable energy budget for twisted tape insert. The convective heat transfer coefficient does not gradually enhance with an increase of particle concentration. The flow features due mainly to the rheology of colloidal dispersions might be a reason for this phenomenon.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2920132','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2920132"><span>The Dynamic Regulation of Microcirculatory <span class="hlt">Conduit</span> Function: Features Relevant to Transfusion Medicine</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Steiner, Marie E; Hebbel, Robert P.</p> <p>2010-01-01</p> <p>The microcirculation is not merely a passive <span class="hlt">conduit</span> for red cell transport, nutrient and gas exchange, but is instead a dynamic participant contributing to the multiple processes involved in the maintenance of metabolic homeostasis and optimal end-organ function. The microcirculation’s angioarchitechture and surface properties influence <span class="hlt">conduit</span> function and flow dynamics over a wide spectrum of conditions, accommodating many different mechanical, pathological or organ-specific responses. The endothelium itself plays a critical role as the interface between tissues and blood components, participating in the regulation of coagulation, inflammation, vascular tone, and permeability. The complex nitric oxide pathways affect vasomotor tone and influence vascular <span class="hlt">conduit</span> caliber and distribution density, alter thrombotic propensity, and modify adhesion molecule expression. Nitric oxide pathways also interact with red blood cells and free hemoglobin moieties in normal and pathological conditions. Red blood cells themselves may affect flow dynamics. Altered rheology and compromised NO bioavailability from medical storage or disease states impede microcirculatory flow and adversely modulate vasodilation. The integration of the microcirculation as a system with respect to flow modulation is delicately balanced, and can be readily disrupted in disease states such as sepsis. This review will provide a comprehensive description of these varied and intricate functions of the microvasculature. PMID:20580315</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5085779','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5085779"><span>Natural Occurring Silks and Their Analogues as Materials for Nerve <span class="hlt">Conduits</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Radtke, Christine</p> <p>2016-01-01</p> <p>Spider silk and its synthetic derivatives have a light weight in combination with good strength and elasticity. Their high cytocompatibility and low immunogenicity make them well suited for biomaterial products such as nerve <span class="hlt">conduits</span>. Silk proteins slowly degrade enzymatically in vivo, thus allowing for an initial therapeutic effect such as in nerve scaffolding to facilitate endogenous repair processes, and then are removed. Silks are biopolymers naturally produced by many species of arthropods including spiders, caterpillars and mites. The silk fibers are secreted by the labial gland of the larvae of some orders of Holometabola (insects with pupa) or the spinnerets of spiders. The majority of studies using silks for biomedical applications use materials from silkworms or spiders, mostly of the genus Nephila clavipes. Silk is one of the most promising biomaterials with effects not only in nerve regeneration, but in a number of regenerative applications. The development of silks for human biomedical applications is of high scientific and clinical interest. Biomaterials in use for biomedical applications have to meet a number of requirements such as biocompatibility and elicitation of no more than a minor inflammatory response, biodegradability in a reasonable time and specific structural properties. Here we present the current status in the field of silk-based <span class="hlt">conduit</span> development for nerve repair and discuss current advances with regard to potential clinical transfer of an implantable nerve <span class="hlt">conduit</span> for enhancement of nerve regeneration. PMID:27775616</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatSR...632235X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatSR...632235X"><span>Long distance seawater intrusion through a karst <span class="hlt">conduit</span> network in the Woodville Karst Plain, Florida</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Zexuan; Bassett, Seth Willis; Hu, Bill; Dyer, Scott Barrett</p> <p>2016-08-01</p> <p>Five periods of increased electrical conductivity have been found in the karst <span class="hlt">conduits</span> supplying one of the largest first magnitude springs in Florida with water. Numerous well-developed <span class="hlt">conduit</span> networks are distributed in the Woodville Karst Plain (WKP), Florida and connected to the Gulf of Mexico. A composite analysis of precipitation and electrical conductivity data provides strong evidence that the increases in conductivity are directly tied to seawater intrusion moving inland and traveling 11 miles against the prevailing regional hydraulic gradient from from Spring Creek Spring Complex (SCSC), a group of submarine springs at the Gulf Coast. A geochemical analysis of samples from the spring vent rules out anthropogenic contamination and upwelling regional recharge from the deep aquifer as sources of the rising conductivity. The interpretation is supported by the conceptual model established by prior researchers working to characterize the study area. This paper documents the first and longest case of seawater intrusion in the WKP, and also indicates significant possibility of seawater contamination through subsurface <span class="hlt">conduit</span> networks in a coastal karst aquifer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1714591C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1714591C"><span>Non-Newtonian rheology of bubble-bearing magmas: effects on <span class="hlt">conduit</span> dynamics.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Colucci, Simone; Papale, Paolo; Montagna, Chiara</p> <p>2015-04-01</p> <p>Non-Newtonian rheology typically arises in magmas from the presence of a dispersed phase. In particular bubbles can reduce or increase the relative viscosity, depending on size and strain regime (i.e., capillary number), for example large bubbles, as well as low strain, reduce the apparent viscosity. In a Non-Newtonian regime it is not possible to define a strain-rate-independent viscosity and the velocity profile is complex. In this work we extended the 1D, steady, isothermal, multiphase non-homogeneous magma ascent model of Papale (2001) to 1.5D to include the Non-Newtonian effect of a bubble-bearing magma. The model has been tested with a basaltic test case. In this way we were able to calculate depth-dependent Non-newtonian velocity profiles across the <span class="hlt">conduit</span> radius along with shear strain-rate and viscosity distributions. Moreover, the model could quantify the effects of the Non-Newtonian rheology on <span class="hlt">conduit</span> flow dynamics, in terms of flow variables (e.g. velocity, pressure). P. Papale (2001). Dynamics of magma flow in volcanic <span class="hlt">conduits</span> with variable fragmentation efficiency and nonequilibrium pumice degassing. JGR, 106, 11043-11065.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4074712','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4074712"><span>Laparoscopic radical cystectomy: neobladder or ileal <span class="hlt">conduit</span>, debate still goes on</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Drewa, Tomasz; Olejniczak, Pawel; Chlosta, Piotr L.</p> <p>2014-01-01</p> <p>Objective To compare the pre, intra, and post–operative data between ileal <span class="hlt">conduit</span> and neobladder urinary diversions during laparoscopic radical cystectomy(LRC). Material and methods Between 2006 and 2011, 63 patients who underwent LRC and urinary diversion had their data input prospectively into a database and said data used for the analysis. The outcome comparators were the patient demographics, operative time, conversion rate, blood loss, transfusion rate, morphine analgesic requirement, length of hospital stay, complication rates, follow up, and quality of life assessments. A Mantel–Haenszel test was used for dichotomous data and an inverse variance method was used for continuous data. P values less than 0.5 were considered significant Results Thirty–nine patients (60 ±7.11 years) had ileal <span class="hlt">conduits</span> and 24 patients (57 ±8.68 years) had neobladder urinary diversion. No difference was found (P >0.05) regarding age, BMI, smoking history, TURBT pathology result, blood loss, blood transfusion requirement, conversion rates, length of hospital stay, morphine requirement, complications, or follow–up and quality of life. The neobladder groups did have more previous abdominal operations and had significantly longer operative time. Conclusions We found no difference between either types of diversion in all comparative aspects except that the neobladder had longer operative times. This is the first comparative study between ileal <span class="hlt">conduit</span> and neobladder urinary diversion after laparoscopic radical cystectomy and can pose as a bench mark for future comparisons. PMID:24982773</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5022204','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5022204"><span><span class="hlt">Conduit</span> and diffuse type groundwater flow regimes in young volcanic terrain</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hicks, B.G. )</p> <p>1993-04-01</p> <p>The Big Butte Springs Watershed Geohydrologic Study (Medford Water Commission and Rogue River National Forest, Medford, OR, 1990) compares the movement of the groundwater supplying these major domestic springs to karstic terrain groundwater flow regimes. The similarity of groundwater velocities and the characteristics of responses to precipitation events in young volcanic groundwater systems warrants the use of <span class="hlt">conduit</span>-like (and diffuse-like) for volcanic terrain to clearly differentiate from the karstic hydrogeologic terms turbulent solution <span class="hlt">conduit</span> flow and diffuse darcian flow''. The <span class="hlt">conduit</span>-like systems in young volcanic terrain includes both the clinkery, rubbly interflow zones and the high hydraulic conductivity (K) basal zones. The basal zones are interpreted to originate as follows: (1) thin lava flows onto rivers/streams yielding through-going continuous groundwater passages by steam explosion and thermal shock, and (2) lava flows cover high K river gravel sequences. The (volcanic) diffuse component originates from fracture systems, minor interflow zones or from streams which were tributary to the pre-lava flow main river system. The presentation will highlight comparisons of data from karstic and volcanic terrain and include descriptions of several world-wide high velocity and high K volcanic groundwater systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4955497','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4955497"><span>Continent catheterizable <span class="hlt">conduit</span> for urinary diversion in children: Applicability and acceptability</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Solanki, Shailesh; Babu, Muniamjanappa Narendra; Jadhav, Vinay; Shankar, Gowri; Ramesh, Santhanakrishnan</p> <p>2015-01-01</p> <p>Background: Continent catheterizable <span class="hlt">conduit</span> (CCC) has made clean intermittent catheterization (CIC) painless and easy. It is applicable in diverse clinical conditions. Nonetheless, convincing the parents for the need of <span class="hlt">conduit</span> procedure is still difficult. Materials and Methods: A prospective study, included children who underwent CCC procedure from March 2008 to February 2013. The data were assessed for; diagnosis, type of <span class="hlt">conduit</span>, number of preoperative counselling sessions before acceptance, role of “self-help group” in decision making, parental concern and satisfaction for the procedure. Results: Twenty-nine patients (males; 24, females; 5) underwent CCC procedure for various clinical conditions. The multiple preoperative counselling sessions and creation of “self-help groups” were helped them for decision making. The main concerns among parents were: (1) Impact of procedure on future fertility and sexual life. (2) Patency of native urethral channel. (3) Permanent urinary stoma over the abdomen. Conclusion: CCC procedures are applicable to a wide array of clinical situations with a good outcome. The acceptability of the CCC procedure improves with preoperative counselling of parent/child, initiation of preoperative per urethral CIC and creation of self-help groups. PMID:25659547</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/7105563','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/7105563"><span>Imaging analysis of platelet deposition on the extracardiac valved <span class="hlt">conduit</span> in humans</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kawata, H.; Matsuda, H.; Isaka, Y.; Kaneko, M.; Matsuwaka, R.; Kobayashi, J.; Matsuki, O.; Nakano, S.; Kimura, K.; Kawashima, Y. )</p> <p>1989-07-01</p> <p>In 14 patients (aged 2-29 yr) with Hancock (n = 11) or Carpentier-Edwards extracardiac valved <span class="hlt">conduits</span> (n = 3), platelet deposition (PD) was investigated using indium 111 ({sup 111}In) platelet imaging. Repeated studies were performed in five patients. By visual analysis, 71% (5/7) of the imagings (7 images/5 patients) showed PD at early study 1-3 months after surgery, 9% (1/11) at intermediate study at 6-46 months (mean 21 mon) (11 images/10 patients) and 0% at late study at 81-132 months (3 images/3 patients). Quantitative analysis was made using relative ratio of radioactivity at the graft area to the area of the brachiocephalic artery (platelet accumulation index or PAI). The PAI was 1.85 {plus minus} 0.47 (mean {plus minus} SD) at early study, 1.51 {plus minus} 0.23 at intermediate, and 1.36 {plus minus} 0.37 at late study (NS). There was no significant difference in the late pressure gradients across the <span class="hlt">conduit</span> (16-68 mon postoperatively) between the two groups with (n = 3) and without (n = 5) PD at the early stage (1-18 mon postoperatively, n = 8). The result may indicate that PD to the valved <span class="hlt">conduit</span> in the right ventricular (RV) outflow tract occurs early postoperatively (mostly within 3 mon). The relationship of the PD detected by this method to late obstruction was not clarified in this study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70030316','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70030316"><span>Gas slug ascent through changes in <span class="hlt">conduit</span> diameter: Laboratory insights into a volcano-seismic source process in low-viscosity magmas</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>James, M.R.; Lane, S.J.; Chouet, B.A.</p> <p>2006-01-01</p> <p>Seismic signals generated during the flow and degassing of low-viscosity magmas include long-period (LP) and very-long-period (VLP) events, whose sources are often attributed to dynamic fluid processes within the <span class="hlt">conduit</span>. We present the results of laboratory experiments designed to investigate whether the passage of a gas slug through regions of changing <span class="hlt">conduit</span> diameter could act as a suitable source mechanism. A vertical, liquid-filled glass tube featuring a concentric diameter change was used to provide canonical insights into potentially deep or shallow seismic sources. As gas slugs ascend the tube, we observe systematic pressure changes varying with slug size, liquid depth, tube diameter, and liquid viscosity. Gas slugs undergoing an abrupt flow pattern change upon entering a section of significantly increased tube diameter induce a transient pressure decrease in and above the flare and an associated pressure increase below it, which stimulates acoustic and inertial resonant oscillations. When the liquid flow is not dominantly <span class="hlt">controlled</span> by viscosity, net vertical forces on the apparatus are also detected. The net force is a function of the magnitude of the pressure transients generated and the tube geometry, which dictates where, and hence when, the traveling pressure pulses can couple into the tube. In contrast to interpretations of related volcano-seismic data, where a single downward force is assumed to result from an upward acceleration of the center of mass in the <span class="hlt">conduit</span>, our experiments suggest that significant downward forces can result from the rapid deceleration of relatively small volumes of downward-moving liquid. Copyright 2006 by the American Geophysical Union.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17125466','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17125466"><span>AT1 receptor blockade prevents the decrease in <span class="hlt">conduit</span> artery flow-mediated dilatation during NOS inhibition in humans.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bellien, Jeremy; Iacob, Michele; Eltchaninoff, Helene; Bourkaib, Ryad; Thuillez, Christian; Joannides, Robinson</p> <p>2007-06-01</p> <p>Whether AT(1) (angiotenin II type 1) receptor blockade can prevent the decrease in <span class="hlt">conduit</span> artery FMD (flow-mediated dilatation) during NOS (nitric oxide synthase) inhibition by alternative endothelial pathways has not been explored previously in humans. In 12 healthy subjects, we measured radial artery diameter (echotracking) and flow (Doppler) during FMD induced by sustained reactive hyperaemia during a <span class="hlt">control</span> period and following NOS inhibition [1.5 mg.min(-1).l(-1) L-NMMA (N(G)-monomethyl-L-arginine)], after a single oral administration of telmisartan (80 mg) or placebo, using a randomized double-blind cross-over design. In six volunteers, we also assessed the roles of prostacyclin and EDHF (endothelium-derived hyperpolarizing factor) during radial FMD after AT(1) receptor blockade by oral administration of aspirin (500 mg) alone, aspirin+L-NMMA or aspirin+L-NMMA+fluconazole (a cytochrome epoxygenases inhibitor; 0.37 mg.min(-1).l(-1)). Telmisartan did not affect radial artery FMD in the <span class="hlt">control</span> period (10.9+/-0.6% with placebo compared with 9.9+/-0.7% with telmisartan), but prevented its decrease after L-NMMA (9.3+/-0.8% with placebo compared with 12.6+/-1.2% with telmisartan; P<0.05) with no modification in baseline parameters, hyperaemia and radial artery endothelium-independent dilatation to sodium nitroprusside. Moreover, in telmisartan-treated subjects, radial artery FMD, compared with <span class="hlt">control</span> (9.0+/-1.0%), was not modified by aspirin alone (9.4+/-0.7%) or associated with L-NMMA (9.5+/-0.5%), but was reduced by the combination of aspirin, L-NMMA and fluconazole (7.5+/-0.6%; P<0.05). These results demonstrate that AT(1) receptor blockade prevents the decrease in <span class="hlt">conduit</span> artery FMD during NOS inhibition in humans, suggesting the development of a compensatory endothelial mechanism. This mechanism appears to be independent of prostacyclin and could possibly be related to an EDHF release.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.V12A..08K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.V12A..08K"><span>Time, temperature and water pressure dependent reheating of volcanic plugs, <span class="hlt">conduits</span> and domes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kennedy, B. M.; Jellinek, M.; Russell, K.</p> <p>2009-12-01</p> <p>Active lava domes show periodic magma supply and are frequently re-intruded and reheated. We propose that the timescale, temperature, and water pressure of reheating <span class="hlt">control</span> whether crack and bubble networks open or close, and whether or not gas can escape. Interpretations of historic eruptions indicate open, permeable magmatic systems favour degassing and non-explosive eruptions, whereas, closed impermeable systems favour pressure build up and explosive eruptions. Despite the observations and interpretations mentioned above, the evolution of open and closed systems during reheating remains poorly understood. We reheated rhyolite dome and pumice samples under open (atmospheric pressure and dry) and closed (pressurized and wet) conditions. Open and closed porosity was measured before and after experiments by helium pycnometry, textures were examined with the Scanning Electron Microscope (SEM), and bulk water contents were measured by infrared spectroscopy during loss on ignition. Open (atmospheric pressure, 200-1100°C) experiments show that (1) short timescales and low temperatures allow degassing without deformation, (2) intermediate timescales and temperatures favour bubble and crack growth, and (3) longer timescales and higher temperatures produce bubble collapse and crack healing. Closed experiments at (450C-750°C and 2-10 MPa) show that, (1) low temperatures and high pressures promote rehydration (regassing) without deformation, and (2) high temperatures at all pressures allow degassing with bubble collapse. Our results indicate that during reheating of an open silicic volcanic plug residual water will degas with little deformation, unless mafic magma temperatures and longer timescales occur. Bubble collapse in remelted enclaves of rhyolite supports that the explosivity of the 1886 basaltic eruption of Mt. Tarawera, New Zealand, may have been enhanced by extreme reheating and sealing of the rhyolite plug by reheating from hot basaltic magma. In contrast, our</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.V51D3060L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.V51D3060L"><span>A Rare Window Into Magmatic <span class="hlt">Conduit</span> Processes: Time Series Observations From Active Lava Lakes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lev, E.; Ruprecht, P.; Patrick, M.; Oppenheimer, C.; Peters, N.; Spampinato, L.; Hernandez Perez, P. A.; Unglert, K.; Barreyre, T.</p> <p>2015-12-01</p> <p>Time-lapse thermal images of the lake surface are used to investigate the circulation and cooling patterns of three lava lakes: Kilauea's Halema'uma'u crater, Mount Erebus, and Nyiragongo. We report results for the time-dependent, two-dimensional velocity and temperature fields of the lake surface. These data sets constrain the locations of flow divergence (upwelling) and convergence (downwelling), the distribution of distinct "plates" and "rifts", the dominant time scales for changes in flow pattern at each lake, and the physical properties of the magma. Upwelling and downwelling locations are strikingly different between the three lakes. Upwelling at Nyiragongo and Erebus occurs dominantly in the interior of the lake, where it is occasionally interrupted by catastrophic downwellings. At Halema'uma'u upwelling and downwelling occur consistently along the perimeter. It remains to be seen whether these differences are dictated merely by the system's geometry or are indicative of intrinsic factors such as melt viscosity, temperature and volatile and crystal content, or of <span class="hlt">conduit</span> processes such as gas pistoning or slug flow. The availability of high resolution data at Halema'uma'u allows as us to document the evolution of crustal plates and rifts and to investigate the physical properties of the lava and the crust. The physical properties of the lake's surface <span class="hlt">control</span> lake cooling rates, and thus need to be included in lake circulation and thermal evolution models. We produce time-temperature cooling curves from surface temperature profiles normal to surface rifts and by tracking the cooling of intra-plate bubble bursts. By comparing observations to analytical cooling models, we estimate a porosity of > 80% during the high stand of the lake, slightly higher than estimates of 70% for the upper 120 meters based on gravity data, and close to the porosity of clasts ejected from the lake during recent minor explosions. Furthermore,we find that the number of surface plates</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25786058','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25786058"><span>Nerve guidance <span class="hlt">conduits</span> from aligned nanofibers: improvement of nerve regeneration through longitudinal nanogrooves on a fiber surface.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Huang, Chen; Ouyang, Yuanming; Niu, Haitao; He, Nanfei; Ke, Qinfei; Jin, Xiangyu; Li, Dawei; Fang, Jun; Liu, Wanjun; Fan, Cunyi; Lin, Tong</p> <p>2015-04-08</p> <p>A novel fibrous <span class="hlt">conduit</span> consisting of well-aligned nanofibers with longitudinal nanogrooves on the fiber surface was prepared by electrospinning and was subjected to an in vivo nerve regeneration study on rats using a sciatic nerve injury model. For comparison, a fibrous <span class="hlt">conduit</span> having a similar fiber alignment structure without surface groove and an autograft were also conducted in the same test. The electrophysiological, walking track, gastrocnemius muscle, triple-immunofluorescence, and immunohistological analyses indicated that grooved fibers effectively improved sciatic nerve regeneration. This is mainly attributed to the highly ordered secondary structure formed by surface grooves and an increase in the specific surface area. Fibrous <span class="hlt">conduits</span> made of longitudinally aligned nanofibers with longitudinal nanogrooves on the fiber surface may offer a new nerve guidance <span class="hlt">conduit</span> for peripheral nerve repair and regeneration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70026436','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70026436"><span>Application of near real-time radial semblance to locate the shallow magmatic <span class="hlt">conduit</span> at Kilauea Volcano, Hawaii</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Dawson, P.; Whilldin, D.; Chouet, B.</p> <p>2004-01-01</p> <p>Radial Semblance is applied to broadband seismic network data to provide source locations of Very-Long-Period (VLP) seismic energy in near real time. With an efficient algorithm and adequate network coverage, accurate source locations of VLP energy are derived to quickly locate the shallow magmatic <span class="hlt">conduit</span> system at Kilauea Volcano, Hawaii. During a restart in magma flow following a brief pause in the current eruption, the shallow magmatic <span class="hlt">conduit</span> is pressurized, resulting in elastic radiation from various parts of the <span class="hlt">conduit</span> system. A steeply dipping distribution of VLP hypocenters outlines a region extending from sea level to about 550 m elevation below and just east of the Halemaumau Pit Crater. The distinct hypocenters suggest the shallow plumbing system beneath Halemaumau consists of a complex plexus of sills and dikes. An unconstrained location for a section of the <span class="hlt">conduit</span> is also observed beneath the region between Kilauea Caldera and Kilauea Iki Crater.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.H13H..06D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.H13H..06D"><span>Fractures as Advective <span class="hlt">Conduits</span> at the Earth Atmosphere Interface</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dragila, M. I.; Weisbrod, N.; Nachshon, U.; Kamai, T.</p> <p>2012-12-01</p> <p>Understanding gas exchange between the Earth's upper crust and the atmosphere is vital and necessary because this phenomenon <span class="hlt">controls</span> to a large extent many important processes including, the water cycle, agricultural activities, greenhouse gas emissions and more. From a hydrological aspect, water vapor transport is an extremely important process related to Earth-atmosphere gas exchange because it affects above ground water vapor concentration, soil water content and soil salinity. Traditionally, diffusion was considered the main mechanism of gas exchange between the atmosphere and vadose zone, driven by gas concentration gradients. While this assumption may be correct for many porous media, our laboratory and field-scale studies have shown that advective gas transport mechanisms are governing these fluxes in fractured rocks and cracked soils. Convection driven by thermal gradients (free convection) and wind induced (forced convection) were explored and both were found to play a major role in Earth-atmosphere gas exchange. Long-term laboratory experiments using fracture simulators in a customized climate <span class="hlt">controlled</span> laboratory have shown that thermal convection occurs when nighttime thermal conditions prevail. This convective venting significantly enhances evaporation and subsequently salt precipitation on the fracture walls. Experiment results were used to develop an empirical relationship between temperature gradients, fracture aperture and convective gas flux through the fracture. Theoretical calculations show that thermal convection is indeed likely to play a major role in evaporation from fractures and can explain enhanced salt accumulation observed in surface-exposed fractures. Long-term field measurements, carried out continuously for 5+ years in a single fracture in the Israeli Negev Desert, verified the development of air convection cycles of 10-18 hours duration on a daily basis, with a peak in both convective flux and duration during the winter. During</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28213098','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28213098"><span>Gelatin-based 3D <span class="hlt">conduits</span> for transdifferentiation of mesenchymal stem cells into Schwann cell-like phenotypes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Uz, Metin; Büyüköz, Melda; Sharma, Anup D; Sakaguchi, Donald S; Altinkaya, Sacide Alsoy; Mallapragada, Surya K</p> <p>2017-02-16</p> <p>In this study, gelatin-based 3D <span class="hlt">conduits</span> with three different microstructures (nanofibrous, macroporous and ladder-like) were fabricated for the first time via combined molding and thermally induced phase separation (TIPS) technique for peripheral nerve regeneration. The effects of <span class="hlt">conduit</span> microstructure and mechanical properties on the transdifferentiation of bone marrow-derived mesenchymal stem cells (MSCs) into Schwann cell (SC) like phenotypes were examined to help facilitate neuroregeneration and understand material-cell interfaces. Results indicated that 3D macroporous and ladder-like structures enhanced MSC attachment, proliferation and spreading, creating interconnected cellular networks with large numbers of viable cells compared to nanofibrous and 2D-tissue culture plate counterparts. 3D-ladder-like <span class="hlt">conduit</span> structure with complex modulus of ∼0.4×10(6)Pa and pore size of ∼150μm provided the most favorable microenvironment for MSC transdifferentiation leading to ∼85% immunolabeling of all SC markers. On the other hand, the macroporous <span class="hlt">conduits</span> with complex modulus of ∼4×10(6)Pa and pore size of ∼100μm showed slightly lower (∼65% for p75, ∼75% for S100 and ∼85% for S100β markers) immunolabeling. Transdifferentiated MSCs within 3D-ladder-like <span class="hlt">conduits</span> secreted significant amounts (∼2.5pg/mL NGF and ∼0.7pg/mL GDNF per cell) of neurotrophic factors, while MSCs in macroporous <span class="hlt">conduits</span> released slightly lower (∼1.5pg/mL NGF and 0.7pg/mL GDNF per cell) levels. PC12 cells displayed enhanced neurite outgrowth in media conditioned by <span class="hlt">conduits</span> with transdifferentiated MSCs. Overall, <span class="hlt">conduits</span> with macroporous and ladder-like 3D structures are promising platforms in transdifferentiation of MSCs for neuroregeneration and should be further tested in vivo.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27570167','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27570167"><span>Enhanced noradrenergic axon regeneration into schwann cell-filled PVDF-TrFE <span class="hlt">conduits</span> after complete spinal cord transection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lee, Yee-Shuan; Wu, Siliang; Arinzeh, Treena Livingston; Bunge, Mary Bartlett</p> <p>2017-02-01</p> <p>Schwann cell (SC) transplantation has been utilized for spinal cord repair and demonstrated to be a promising therapeutic strategy. In this study, we investigated the feasibility of combining SC transplantation with novel <span class="hlt">conduits</span> to bridge the completely transected adult rat spinal cord. This is the first and initial study to evaluate the potential of using a fibrous piezoelectric polyvinylidene fluoride trifluoroethylene (PVDF-TrFE) <span class="hlt">conduit</span> with SCs for spinal cord repair. PVDF-TrFE has been shown to enhance neurite growth in vitro and peripheral nerve repair in vivo. In this study, SCs adhered and proliferated when seeded onto PVDF-TrFE scaffolds in vitro. SCs and PVDF-TrFE <span class="hlt">conduits</span>, consisting of random or aligned fibrous inner walls, were transplanted into transected rat spinal cords for 3 weeks to examine early repair. Glial fibrillary acidic protein (GFAP)(+) astrocyte processes and GFP (green fluorescent protein)-SCs were interdigitated at both rostral and caudal spinal cord/SC transplant interfaces in both types of <span class="hlt">conduits</span>, indicative of permissivity to axon growth. More noradrenergic/DβH(+) (dopamine-beta-hydroxylase) brainstem axons regenerated across the transplant when greater numbers of GFAP(+) astrocyte processes were present. Aligned <span class="hlt">conduits</span> promoted extension of DβH(+) axons and GFAP(+) processes farther into the transplant than random <span class="hlt">conduits</span>. Sensory CGRP(+) (calcitonin gene-related peptide) axons were present at the caudal interface. Blood vessels formed throughout the transplant in both <span class="hlt">conduits</span>. This study demonstrates that PVDF-TrFE <span class="hlt">conduits</span> harboring SCs are promising for spinal cord repair and deserve further investigation. Biotechnol. Bioeng. 2017;114: 444-456. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27397950','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27397950"><span><span class="hlt">Conduit</span> margin heating and deformation during the AD 1886 basaltic Plinian eruption at Tarawera volcano, New Zealand.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schauroth, Jenny; Wadsworth, Fabian B; Kennedy, Ben; von Aulock, Felix W; Lavallée, Yan; Damby, David E; Vasseur, Jérémie; Scheu, Bettina; Dingwell, Donald B</p> <p></p> <p>During explosive eruptions, a suspension of gas and pyroclasts rises rapidly within a <span class="hlt">conduit</span>. Here, we have analysed textures preserved in the walls of a pyroclastic feeder dyke of the AD 1886 Tarawera basaltic Plinian fissure eruption. The samples examined consist of basaltic ash and scoria plastered onto a <span class="hlt">conduit</span> wall of a coherent rhyolite dome and a welded rhyolitic dome breccia. We examine the textural evidence for the response of the wall material, built of ∼75 vol.% glass and ∼25 vol.% crystals (pore-free equivalent), to mass movement in the adjacent <span class="hlt">conduit</span>. In the rhyolitic wall material, we quantify the orientation and aspect ratio of biotite crystals as strain markers of simple shear deformation, and interpret juxtaposed regions of vesiculation and vesicle collapse as evidence of <span class="hlt">conduit</span> wall heating. Systematic changes occur close to the margin: (1) porosity is highly variable, with areas locally vesiculated or densified, (2) biotite crystals are oriented with their long axis parallel to the margin, (3) the biotites have greater aspect ratios close to the margin and (4) the biotite crystals are fractured. We interpret the biotite phenocryst deformation to result from crystal fracture, rotation and cleavage-parallel bookcase translation. These textural observations are inferred to indicate mechanical coupling between the hot gas-ash jet and the <span class="hlt">conduit</span> wall and reheating of wall rock rhyolite. We couple these observations with a simple 1D conductive heating model to show what minimum temperature the <span class="hlt">conduit</span> wall needs to reach in order to achieve a temperature above the glass transition throughout the texturally-defined deformed zone. We propose that <span class="hlt">conduit</span> wall heating and resulting deformation influences <span class="hlt">conduit</span> margin outgassing and may enhance the intensity of such large basaltic eruptions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011GeoRL..3817310C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011GeoRL..3817310C"><span>X-ray computed-tomography imaging of gas migration in water-saturated sediments: From capillary invasion to <span class="hlt">conduit</span> opening</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Choi, Jeong-Hoon; Seol, Yongkoo; Boswell, Ray; Juanes, Ruben</p> <p>2011-09-01</p> <p>The strong coupling between multiphase flow and sediment mechanics determines the spatial distribution and migration dynamics of gas percolating through liquid-filled soft granular media. Here, we investigate, by means of <span class="hlt">controlled</span> experiments and computed tomography (CT) imaging, the preferential mode of gas migration in three-dimensional samples of water-saturated silica-sand and silica-silt sediments. Our experimental system allowed us to independently <span class="hlt">control</span> radial and axial confining stresses and pore pressure while performing continuous x-ray CT scanning. The CT image analysis of the three-dimensional gas migration provides the first experimental confirmation that capillary invasion preferentially occurs in coarse-grained sediments whereas grain displacement and <span class="hlt">conduit</span> openings are dominant in fine-grained sediments. Our findings allow us to rationalize prior field observations and pore-scale modeling results, and provide critical experimental evidence to explain the means by which <span class="hlt">conduits</span> for the transit of methane gas may be established through the gas hydrate stability zone in oceanic sediments, and cause large episodic releases of carbon into the deep ocean.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA.....7294W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA.....7294W"><span>Using ballistic bombs at Pichincha volcano, Ecuador as a proxy for <span class="hlt">conduit</span> dynamics in Vulcanian eruptions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wright, H.; Rosi, M.; Cioni, R.; Cashman, K.</p> <p>2003-04-01</p> <p>Vulcanian eruptions are perhaps the most common style of eruptive activity at intermediate composition volcanoes, as they often precede and/or follow much larger Plinian events. Vulcanian eruptions occur in energetic, short-duration pulses and eject relatively small amounts of material. However, although each pulse has been inferred to represent the ejection of a shallow <span class="hlt">conduit</span> plug, the dynamics and mechanics of vulcanian eruptions are not well understood; the character of the material that is ejected, the amount of erupted material, the pressurization conditions preceding eruption, and the maximum depth that these eruptions tap are unresolved questions. To address conditions leading to Vulcanian eruptions, we are studying ballistic bombs ejected from the 1999-2000 vulcanian eruptions at Guagua Pichincha volcano, Ecuador. Bomb types range from dense to highly vesicular, with many exhibiting the breadcrusting that is ubiquitous in Vulcanian deposits. Clast morphology varies with clast density, with slightly vesicular bombs having thick, glassy crusts with widely spaced cracks, while more vesicular bombs have thinner crusts and more closely spaced crack patterns. We suggest that the wide range of clast types may represent the stratigraphy of the uppermost <span class="hlt">conduit</span> prior to each eruptive event, with denser blocks representing more degassed magma from near the top of the pre-eruptive <span class="hlt">conduit</span> plug and more vesicular blocks representing deeper, less degassed levels in the <span class="hlt">conduit</span>. Quantification of both the breadcrust crack structures (e.g. crack orientation, density of the rind, and crack spacing) and the interior porosity and permeability of each bomb type allows us to examine the thermal, vesiculation and expansion history of the erupted material. Different breadcrust types experienced variable degrees of expansion. For example, the volume expansion of the most vesicular clast is ~6% based on the relationship between crack volume and total bomb volume, whereas the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3875632','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3875632"><span>Blood Pressure Regulation VIII: Resistance Vessel Tone and Implications for a Pro-Atherogenic <span class="hlt">Conduit</span> Artery Endothelial Cell Phenotype</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Padilla, Jaume; Jenkins, Nathan T.; Laughlin, M. Harold; Fadel, Paul J.</p> <p>2013-01-01</p> <p>Dysfunction of the endothelium is proposed as the primary initiator of atherosclerotic peripheral artery disease, which occurs mainly in medium to large-sized <span class="hlt">conduit</span> arteries of the lower extremities (e.g., iliac, femoral, popliteal arteries). In this review article, we propose the novel concept that <span class="hlt">conduit</span> artery endothelial cell phenotype is determined, in part, by microvascular tone in skeletal muscle resistance arteries through both changes in arterial blood pressure as well as upstream <span class="hlt">conduit</span> artery shear stress patterns. First, we summarize the literature supporting the involvement of sympathetic nerve activity (SNA) and nitric oxide (NO) in the modulation of microvascular tone and arterial blood pressure. We then focus on the role of elevated blood pressure and shear stress profiles in modulating <span class="hlt">conduit</span> artery endothelial cell phenotype. Last, we discuss findings from classic and emerging studies indicating that increased vascular resistance, as it occurs in the context of increased SNA and/or reduced NO bioavailability, is associated with greater oscillatory shear stress (e.g., increased retrograde shear) in upstream <span class="hlt">conduit</span> arteries. The ideas put forth in this review set the stage for a new paradigm concerning the mechanistic link between increased microvascular tone and development of <span class="hlt">conduit</span> artery endothelial dysfunction and thus increased risk for peripheral artery disease. Indeed, a vast amount of evidence supports the notion that excessive blood pressure and oscillatory shear stress are potent pro-atherogenic signals to the endothelium. PMID:23860841</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22949528','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22949528"><span>α-adrenergic vasoconstriction contributes to the age-related increase in <span class="hlt">conduit</span> artery retrograde and oscillatory shear.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Casey, Darren P; Padilla, Jaume; Joyner, Michael J</p> <p>2012-10-01</p> <p>Aging is associated with increased retrograde and oscillatory shear in peripheral <span class="hlt">conduit</span> arteries of humans. Although the mechanisms responsible for these age-related changes are not completely understood, augmented downstream α-adrenergic tone likely plays a significant role in this phenomenon. Therefore, in protocol 1, brachial artery diameter and blood velocity were measured via Doppler ultrasound during (1) rest (<span class="hlt">control</span>), (2) endogenous norepinephrine release via intra-arterial infusions of tyramine, and (3) α-adrenergic blockade via infusions of phentolamine in young healthy humans (n=12). Tyramine increased brachial artery retrograde (-4.0±1.4 to -9.5±1.4 s(-1)) and oscillatory shear (0.05±0.02 to 0.18±0.05 arbitrary units), whereas phentolamine abolished retrograde and oscillatory shear (P<0.05). Additionally, in protocol 2, we examined brachial artery shear patterns in young (n=12; 29±2 years) and older (n=13; 69±2 years) healthy adults during (1) rest (<span class="hlt">control</span>), (2) sympathetic activation via lower body negative pressure, and (3) infusion of phentolamine. At rest, older adults exhibited greater brachial artery retrograde and oscillatory shear (-9.9±2.7 s(-1) and 0.11±0.03 arbitrary units, respectively) compared with younger adults (-3.1±1.0 s(-1) and 0.05±0.02 arbitrary units, respectively; P<0.05 for both). Lower body negative pressure increased retrograde and oscillatory shear in young (P<0.05), but not older adults (P=0.85-0.97), such that differences between young and older were eliminated (P>0.05). During infusion of phentolamine, retrograde and oscillatory shear were abolished in young adults (P<0.05) and markedly reduced, yet still persistent, in older adults (P<0.01). Our data indicate that α-adrenergic vasoconstriction is a major contributor to age-related discrepancies in <span class="hlt">conduit</span> artery shear-rate patterns at rest.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.V21B2709S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.V21B2709S"><span><span class="hlt">Conduit</span> Processes Driving Pre-explosive Harmonic Tremor in the 2009 Redoubt Volcano Eruption</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Summers, P.; Dunham, E. M.</p> <p>2013-12-01</p> <p>During the 2009 eruption of Redoubt Volcano, Alaska, gliding harmonic tremor was observed before many vulcanian explosions. Though harmonic tremor is relatively common at volcanoes, the high fundamental frequency of these tremors (up to 30 Hz) is unique and of particular interest. Hotovec et al. (JVGR, 2013) linked this tremor to rapidly repeating magnitude ~1 earthquakes located a few kilometers beneath the vent. These events might be occurring as brittle failure of the magma or as slip along the margins of an obstruction within the <span class="hlt">conduit</span>. Using a frictional faulting model, Dmitrieva et al. (Nature Geoscience, 2013) converted the seismicity and tremor signals into an estimate of the history of shear stresses acting on the fault surface and causing slip. Stressing rates increased, in a nonlinear manner, from less than 1 MPa/s to about 20 MPa/s over the final ten minutes before the explosions. Here we investigate what <span class="hlt">conduit</span> processes could plausibly be responsible for such high stressing rates. One possibility is that a blockage develops in the <span class="hlt">conduit</span> prior to each explosion, perhaps from a crystal-rich magma plug or collapse of the <span class="hlt">conduit</span> walls. This obstacle temporarily prevents upward flow of magma, while deeper influx from below thus compresses and pressurizes magma in the <span class="hlt">conduit</span> beneath the blockage. This compression largely occurs between the base of the obstruction and the H2O exsolution depth, which petrologic estimates of volatile content and standard solubility laws suggest is nominally located about a kilometer or two deeper than the blockage. We solve the unsteady <span class="hlt">conduit</span> flow equations (mass and momentum balance for a compressible, viscous mixture of gas and liquid). Gas exsolution is treated with Henry's law, and in our present models exsolution begins abruptly below a critical pressure. No flow is permitted past the blockage and the system is driven by steady influx at depth. We find that as magma accumulates within the <span class="hlt">conduit</span> beneath the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1211147T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1211147T"><span>Linking observations at active volcanoes to physical processes through <span class="hlt">conduit</span> flow modelling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thomas, Mark; Neuberg, Jurgen</p> <p>2010-05-01</p> <p>Low frequency seismic events observed on volcanoes such as Soufriere hills, Montserrat may offer key indications about the state of a volcanic system. To obtain a better understanding of the source of these events and of the physical processes that take place within a volcano it is necessary to understand the conditions of magma a depth. This can be achieved through <span class="hlt">conduit</span> flow modelling (Collier & Neuberg, 2006). 2-D compressible Navier-Stokes equations are solved through a Finite Element approach, for differing initial water and crystal contents, magma temperatures, chamber overpressures and geometric shapes of <span class="hlt">conduit</span>. In the fully interdependent modelled system each of these variables has an effect on the magma density, viscosity, gas content, and also the pressure within the flow. These variables in turn affect the magma ascent velocity and the overall eruption dynamics of an active system. Of particular interest are the changes engendered in the flow by relativity small variations in the <span class="hlt">conduit</span> geometry. These changes can have a profound local effect of the ascent velocity of the magma. By restricting the width of 15m wide, 5000m long vertical <span class="hlt">conduit</span> over a 100m distance a significant acceleration of the magma is seen in this area. This has implications for the generation of Low-Frequency (LF) events at volcanic systems. The strain-induced fracture of viscoelastic magma or brittle failure of melt has been previously discussed as a possible source of LF events by several authors (e.g. Tuffen et al., 2003; Neuberg et al., 2006). The location of such brittle failure however has been seen to occur at relativity shallow depths (<1000m), which does not agree with the location of recorded LF events. By varying the geometry of the <span class="hlt">conduit</span> and causing accelerations in the magma flow, localised increases in the shear strain rate of up to 30% are observed. This provides a mechanism of increasing the depth over witch brittle failure of melt may occur. A key observable</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/id0444.photos.223917p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/id0444.photos.223917p/"><span>IET <span class="hlt">control</span> building (TAN620). <span class="hlt">control</span> room. facing north. <span class="hlt">control</span> consoles ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>IET <span class="hlt">control</span> building (TAN-620). <span class="hlt">control</span> room. facing north. <span class="hlt">control</span> consoles have been removed. Openings in floor were communication and <span class="hlt">control</span> <span class="hlt">conduits</span>. Periscope <span class="hlt">controls</span> at center left (see also HAER No. ID-33-E-20). INEEL negative no. HD-21-3-1 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1610493L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1610493L"><span>Application of a new multiphase multicomponent volcanic <span class="hlt">conduit</span> model with magma degassing and crystallization to Stromboli volcano.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>La Spina, Giuseppe; Burton, Mike; de'Michieli Vitturi, Mattia</p> <p>2014-05-01</p> <p> reproduce both effusive and explosive eruptive activities at Stromboli volcano. Three different crystal components (olivine, pyroxene and feldspar) and two different gas species (water and carbon dioxide) are taken into account. The equilibrium profiles of crystallization as function of pressure, temperature and water content are modeled using the numerical codes AlphaMELTS and DAKOTA. The equilibrium of dissolved gas content, instead, is obtained using a non-linear fitting of data computed using VolatileCALC. With these data, we simulate numerically the lava effusion that occurred at Stromboli between 27 February and 2 April 2007, and find good agreement with the observed data (vesicularity, exsolved gas composition, crystal content and mass flow rate) at the vent. We find that the model is highly sensitive to input magma temperature, going from effusive to explosive eruption with temperature changes by just 20 °C. We thoroughly investigated through a sensitivity analysis the <span class="hlt">control</span> of the temperature of magma chamber and of the radius of the <span class="hlt">conduit</span> on the mass flow rate, obtaining also a set of admissible temperatures and <span class="hlt">conduit</span> radii that produce results in agreement with the real observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25085857','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25085857"><span>A comparison of the performance of mono- and bi-component electrospun <span class="hlt">conduits</span> in a rat sciatic model.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cirillo, Valentina; Clements, Basak A; Guarino, Vincenzo; Bushman, Jared; Kohn, Joachim; Ambrosio, Luigi</p> <p>2014-10-01</p> <p>Synthetic nerve <span class="hlt">conduits</span> represent a promising strategy to enhance functional recovery in peripheral nerve injury repair. However, the efficiency of synthetic nerve <span class="hlt">conduits</span> is often compromised by the lack of molecular factors to create an enriched microenvironment for nerve regeneration. Here, we investigate the in vivo response of mono (MC) and bi-component (BC) fibrous <span class="hlt">conduits</span> obtained by processing via electrospinning poly(ε-caprolactone) (PCL) and gelatin solutions. In vitro studies demonstrate that the inclusion of gelatin leads to uniform electrospun fiber size and positively influences the response of Dorsal Root Ganglia (DRGs) neurons as confirmed by the preferential extensions of neurites from DRG bodies. This behavior can be attributed to gelatin as a bioactive cue for the cultured DRG and to the reduced fibers size. However, in vivo studies in rat sciatic nerve defect model show an opposite response: MC <span class="hlt">conduits</span> stimulate superior nerve regeneration than gelatin containing PCL <span class="hlt">conduits</span> as confirmed by electrophysiology, muscle weight and histology. The G-ratio, 0.71 ± 0.07 for MC and 0.66 ± 0.05 for autograft, is close to 0.6, the value measured in healthy nerves. In contrast, BC implants elicited a strong host response and infiltrating tissue occluded the <span class="hlt">conduits</span> preventing the formation of myelinated axons. Therefore, although gelatin promotes in vitro nerve regeneration, we conclude that bi-component electrospun <span class="hlt">conduits</span> are not satisfactory in vivo due to intrinsic limits to their mechanical performance and degradation kinetics, which are essential to peripheral nerve regeneration in vivo. Copyright © 2014 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28138239','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28138239"><span>Nerve guidance <span class="hlt">conduit</span> with a hybrid structure of a PLGA microfibrous bundle wrapped in a micro/nanostructured membrane.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Peng, Shih-Wen; Li, Ching-Wen; Chiu, Ing-Ming; Wang, Gou-Jen</p> <p>2017-01-01</p> <p>Nerve repair in tissue engineering involves the precise construction of a scaffold to guide nerve cell regeneration in the desired direction. However, improvements are needed to facilitate the cell migration/growth rate of nerves in the center of a nerve <span class="hlt">conduit</span>. In this paper, we propose a nerve guidance <span class="hlt">conduit</span> with a hybrid structure comprising a microfibrous poly(lactic-co-glycolic acid) (PLGA) bundle wrapped in a micro/nanostructured PLGA membrane. We applied sequential fabrication processes, including photolithography, nano-electroforming, and polydimethylsiloxane casting to manufacture master molds for the repeated production of the PLGA subelements. After demolding it from the master molds, we rolled the microfibrous membrane into a bundle and then wrapped it in the micro/nanostructured membrane to form a nerve-guiding <span class="hlt">conduit</span>. We used KT98/F1B-GFP cells to estimate the migration rate and guidance ability of the fabricated nerve <span class="hlt">conduit</span> and found that both elements increased the migration rate 1.6-fold compared with a flat PLGA membrane. We also found that 90% of the cells in the hybrid nano/microstructured membrane grew in the direction of the designed patterns. After 3 days of culturing, the interior of the nerve <span class="hlt">conduit</span> was filled with cells, and the microfiber bundle was also surrounded by cells. Our <span class="hlt">conduit</span> cell culture results also demonstrate that the proposed micro/nanohybrid and microfibrous structures can retain their shapes. The proposed hybrid-structured <span class="hlt">conduit</span> demonstrates a high capability for guiding nerve cells and promoting cell migration, and, as such, is feasible for use in clinical applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.S51D2728L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.S51D2728L"><span>A Linearized Model for Wave Propagation through Coupled Volcanic <span class="hlt">Conduit</span>-crack Systems Filled with Multiphase Magma</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liang, C.; Dunham, E. M.; OReilly, O. J.; Karlstrom, L.</p> <p>2015-12-01</p> <p>Both the oscillation of magma in volcanic <span class="hlt">conduits</span> and resonance of fluid-filled cracks (dikes and sills) are appealing explanations for very long period signals recorded at many active volcanoes. While these processes have been studied in isolation, real volcanic systems involve interconnected networks of <span class="hlt">conduits</span> and cracks. The overall objective of our work is to develop a model of wave propagation and ultimately eruptive fluid dynamics through this coupled system. Here, we present a linearized model for wave propagation through a <span class="hlt">conduit</span> with multiple cracks branching off of it. The fluid is compressible and viscous, and is comprised of a mixture of liquid melt and gas bubbles. Nonequilibrium bubble growth and resorption (BGR) is quantified by introducing a time scale for mass exchange between phases, following the treatment in Karlstrom and Dunham (2015). We start by deriving the dispersion relation for crack waves travelling along the multiphase-magma-filled crack embedded in an elastic solid. Dissipation arises from magma viscosity, nonequilibrium BGR, and radiation of seismic waves into the solid. We next introduce coupling conditions between the <span class="hlt">conduit</span> and crack, expressing conservation of mass and the balance of forces across the junction. Waves in the <span class="hlt">conduit</span>, like those in the crack, are influenced by nonequilibrium BGR, but the deformability of the surrounding solid is far less important than for cracks. Solution of the coupled system of equations provides the evolution of pressure and fluid velocity within the <span class="hlt">conduit</span>-crack system. The system has various resonant modes that are sensitive to fluid properties and to the geometry of the <span class="hlt">conduit</span> and cracks. Numerical modeling of seismic waves in the solid allows us to generate synthetic seismograms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JCHyd.110...34F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JCHyd.110...34F"><span>Laboratory analog and numerical study of groundwater flow and solute transport in a karst aquifer with <span class="hlt">conduit</span> and matrix domains</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Faulkner, Jonathan; Hu, Bill X.; Kish, Stephen; Hua, Fei</p> <p>2009-11-01</p> <p>New mathematical and laboratory methods have been developed for simulating groundwater flow and solute transport in karst aquifers having <span class="hlt">conduits</span> imbedded in a porous medium, such as limestone. The Stokes equations are used to model the flow in the <span class="hlt">conduits</span> and the Darcy equation is used for the flow in the matrix. The Beavers-Joseph interface boundary conditions are adopted to describe the flow exchange at the interface boundary between the two domains. A laboratory analog is used to simulate the <span class="hlt">conduit</span> and matrix domains of a karst aquifer. The <span class="hlt">conduit</span> domain is located at the bottom of the transparent plexiglas laboratory analog and glass beads occupy the remaining space to represent the matrix domain. Water flows into and out of the two domains separately and each has its own supply and outflow reservoirs. Water and solute are exchanged through an interface between the two domains. Pressure transducers located within the matrix and <span class="hlt">conduit</span> domains of the analog provide data that is processed and stored in digital format. Dye tracing experiments are recorded using time-lapse imaging. The data and images produced are analyzed by a spatial analysis program. The experiments provide not only hydraulic head distribution but also capture solute front images and mass exchange measurements between the <span class="hlt">conduit</span> and matrix domains. In the experiment, we measure and record pressures, and quantify flow rates and solute transport. The results present a plausible argument that laboratory analogs can characterize groundwater water flow, solute transport, and mass exchange between the <span class="hlt">conduit</span> and matrix domains in a karst aquifer. The analog validates the predictions of a numerical model and demonstrates the need of laboratory analogs to provide verification of proposed theories and the calibration of mathematical models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5238773','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5238773"><span>Nerve guidance <span class="hlt">conduit</span> with a hybrid structure of a PLGA microfibrous bundle wrapped in a micro/nanostructured membrane</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Peng, Shih-Wen; Li, Ching-Wen; Chiu, Ing-Ming; Wang, Gou-Jen</p> <p>2017-01-01</p> <p>Nerve repair in tissue engineering involves the precise construction of a scaffold to guide nerve cell regeneration in the desired direction. However, improvements are needed to facilitate the cell migration/growth rate of nerves in the center of a nerve <span class="hlt">conduit</span>. In this paper, we propose a nerve guidance <span class="hlt">conduit</span> with a hybrid structure comprising a microfibrous poly(lactic-co-glycolic acid) (PLGA) bundle wrapped in a micro/nanostructured PLGA membrane. We applied sequential fabrication processes, including photolithography, nano-electroforming, and polydimethylsiloxane casting to manufacture master molds for the repeated production of the PLGA subelements. After demolding it from the master molds, we rolled the microfibrous membrane into a bundle and then wrapped it in the micro/nanostructured membrane to form a nerve-guiding <span class="hlt">conduit</span>. We used KT98/F1B-GFP cells to estimate the migration rate and guidance ability of the fabricated nerve <span class="hlt">conduit</span> and found that both elements increased the migration rate 1.6-fold compared with a flat PLGA membrane. We also found that 90% of the cells in the hybrid nano/microstructured membrane grew in the direction of the designed patterns. After 3 days of culturing, the interior of the nerve <span class="hlt">conduit</span> was filled with cells, and the microfiber bundle was also surrounded by cells. Our <span class="hlt">conduit</span> cell culture results also demonstrate that the proposed micro/nanohybrid and microfibrous structures can retain their shapes. The proposed hybrid-structured <span class="hlt">conduit</span> demonstrates a high capability for guiding nerve cells and promoting cell migration, and, as such, is feasible for use in clinical applications. PMID:28138239</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016CoMP..171...60C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016CoMP..171...60C"><span>Confort 15 model of <span class="hlt">conduit</span> dynamics: applications to Pantelleria Green Tuff and Etna 122 BC eruptions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Campagnola, S.; Romano, C.; Mastin, L. G.; Vona, A.</p> <p>2016-06-01</p> <p>Numerical simulations are useful tools to illustrate how flow parameters and physical processes may affect eruption dynamics of volcanoes. In this paper, we present an updated version of the Conflow model, an open-source numerical model for flow in eruptive <span class="hlt">conduits</span> during steady-state pyroclastic eruptions (Mastin and Ghiorso in A numerical program for steady-state flow of magma-gas mixtures through vertical eruptive <span class="hlt">conduits</span>. U.S. Geological Survey Open File Report 00-209, 2000). In the modified version, called Confort 15, the rheological constraints are improved, incorporating the most recent constitutive equations of both the liquid viscosity and crystal-bearing rheology. This allows all natural magma compositions, including the peralkaline melts excluded in the original version, to be investigated. The crystal-bearing rheology is improved by computing the effect of strain rate and crystal shape on the rheology of natural magmatic suspensions and expanding the crystal content range in which rheology can be modeled compared to the original version ( Conflow is applicable to magmatic mixtures with up to 30 vol% crystal content). Moreover, volcanological studies of the juvenile products (crystal and vesicle size distribution) of the investigated eruption are directly incorporated into the modeling procedure. Vesicle number densities derived from textural analyses are used to calculate, through Toramaru equations, maximum decompression rates experienced during ascent. Finally, both degassing under equilibrium and disequilibrium conditions are considered. This allows considerations on the effect of different fragmentation criteria on the <span class="hlt">conduit</span> flow analyses, the maximum volume fraction criterion ("porosity criterion"), the brittle fragmentation criterion and the overpressure fragmentation criterion. Simulations of the pantelleritic and trachytic phases of the Green Tuff (Pantelleria) and of the Plinian Etna 122 BC eruptions are performed to test the upgrades in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DFDH36004N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DFDH36004N"><span>Nano bubble migration in a tapered <span class="hlt">conduit</span> in the asymptotic limits of zero capillary and Bond Numbers - Theory and Experiments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Norton, Michael; Ross, Frances; Bau, Haim</p> <p>2015-11-01</p> <p>Using a hermetically sealed liquid cell, we observed the growth and migration of bubbles (tens to hundreds of nanometers in diameter) in a tapered <span class="hlt">conduit</span> and supersaturated solution with a transmission electron microscope. To better understand bubble shape and migration dynamics, we developed simple 2D and 3D models valid in the limit of zero capillary and Bond numbers. The 3D model is restricted to small taper slope, weakly non-circular contact line geometries and large bubble aspect ratio (high confinement), and was solved using a pseudo-spectral decomposition. Both models utilize the Blake-Haynes mechanism to relate dynamic contact angle to local contact line velocity The influence of pinning of a portion of the contact line on bubble geometry is also considered. Contact line dissipation <span class="hlt">controls</span> curvature and regulates growth rate. Our 2D and 3D models predict growth rates in agreement with experimental observations, but several orders of magnitude lower than predicted by the classical Epstein - Plesset theory. The work was supported, in part, by NSF CBET grant 1066573.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19617641','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19617641"><span>Hypotrophic effect of long-term neuronal NO-synthase inhibition on heart and <span class="hlt">conduit</span> arteries of the Wistar rats.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kristek, F; Cacanyiova, S; Gerova, M</p> <p>2009-06-01</p> <p>We demonstrate the effect of long-term nNOS inhibition with 7-nitroindazole (7NI) on the heart and <span class="hlt">conduit</span> arteries. Ten weeks old Wistar rats were used: two groups of <span class="hlt">controls</span> and rats receiving 7-NI (10 mg/kg b.w./day) for 6 weeks in drinking water. Blood pressure (BP) was measured by the plethysmographic method. In first group mesenteric, carotid and coronary arteries were excised after perfusion fixation (120 mmHg) for morphological study, in second group mesenteric artery was taken for functional investigation. 7NI did not affect BP, heart/body weight was decreased. In all arteries inner diameter (ID) did not changed, wall thickness (WT) (intima+media), cross sectional area (CSA) (intima+media), and WT/ID decreased. In carotid artery volume density (VD) (percentual proportion) of intima and media did not change; VD and CSAs of endothelial and smooth muscle cells decreased, CSAs of extracellular matrix in intima and media did not change. No difference was found in relaxation of mesenteric artery to acetylcholine (10(-9)-10(-5) mol/L). Contraction induced by transmural nerve stimulation (8 Hz) augmented and contraction to exogennous noradrenaline (10(-9)-10(-5) mol/L) attenuated. Long-term 7NI administration evoked pressure independent cardiac hypotrophy and due to decrease of endothelial and smooth muscle cell mass arterial wall hypotrophy associated with decreased contractile efficiency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5011611','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5011611"><span>The use of electrical resistivity techniques to detect an underground <span class="hlt">conduit</span> in the karst regions of the Inner Bluegrass</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bonita, J.; Sendlein, L.V.A. . Dept. of Geological Sciences)</p> <p>1993-03-01</p> <p>Electrical resistivity studies conducted within the Inner Bluegrass Karst Region have been employed to map the presence of a fracture <span class="hlt">controlled</span> solution that drains the royal Spring Basin. Exist theories by authors such as Thrailkill (1982) suggest that the Inner Bluegrass Karst Region is divided into basin and interbasin areas, with the zone of active meteoric water circulation at deep depths below the surface in basin areas and flow within a few meters of the surface in interbasin areas. Initial resistivity soundings were performed along various traverses to access information on the underlying lexington Limestone. Sounding curves calculated form the modeling program RESIX indicate that low resistivity zones occur at two distinctly different depth intervals, denoting the boundary between the basin and interbasin areas. Information from electric resistivity profiles within this now defined basin area indicate resistivity anomalies trending in linear segments of N45W and N40E. Fracture and joint orientation measurements at roadcuts and on topographic maps and air photographs also indicate a preferential orientation parallel to the orientation of the linear segments of the <span class="hlt">conduit</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4660758','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4660758"><span>Electrospun and woven silk fibroin/poly(lactic-co-glycolic acid) nerve guidance <span class="hlt">conduits</span> for repairing peripheral nerve injury</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wang, Ya-ling; Gu, Xiao-mei; Kong, Yan; Feng, Qi-lin; Yang, Yu-min</p> <p>2015-01-01</p> <p>We have designed a novel nerve guidance <span class="hlt">conduit</span> (NGC) made from silk fibroin and poly(lactic-co-glycolic acid) through electrospinning and weaving (ESP-NGCs). Several physical and biological properties of the ESP-NGCs were assessed in order to evaluate their biocompatibility. The physical properties, including thickness, tensile stiffness, infrared spectroscopy, porosity, and water absorption were determined in vitro. To assess the biological properties, Schwann cells were cultured in ESP-NGC extracts and were assessed by morphological observation, the MTT assay, and immunohistochemistry. In addition, ESP-NGCs were subcutaneously implanted in the backs of rabbits to evaluate their biocompatibility in vivo. The results showed that ESP-NGCs have high porosity, strong hydrophilicity, and strong tensile stiffness. Schwann cells cultured in the ESP-NGC extract fluids showed no significant differences compared to <span class="hlt">control</span> cells in their morphology or viability. Histological evaluation of the ESP-NGCs implanted in vivo indicated a mild inflammatory reaction and high biocompatibility. Together, these data suggest that these novel ESP-NGCs are biocompatible, and may thus provide a reliable scaffold for peripheral nerve repair in clinical application. PMID:26692862</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25448645','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25448645"><span>Pulsed electromagnetic fields accelerate functional recovery of transected sciatic nerve bridged by chitosan <span class="hlt">conduit</span>: an animal model study.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mohammadi, Rahim; Faraji, Darab; Alemi, Hanieh; Mokarizadeh, Aram</p> <p>2014-12-01</p> <p>Effect of whole body exposure to pulsed electromagnetic fields (PEMF) on nerve regeneration in a rat sciatic nerve transection model was assessed. Sixty male white Wistar rats were divided into four experimental groups (n = 15), randomly: In transected group (TC) left sciatic nerve was transected and stumps were fixed in adjacent muscle. In chitosan group (CHIT) the defect was bridged using a chitosan <span class="hlt">conduit</span> filled with phosphate-buffered saline. In treatment group (CHIT/PEMF) the whole body was exposed to PEMF (0.3 mT, 2 Hz) for 4 h/day within 1-5 days. In normal <span class="hlt">control</span> group (NC) sciatic nerve was only dissected and manipulated. Each group was subdivided into three subgroups of five animals each and nerve fibers were studied 4, 8 and 12 weeks after surgery. Behavioral, functional, electrophysiological, biomechanical, gastrocnemius muscle mass findings and morphometric indices confirmed faster recovery of regenerated axons in CHIT/PEMF than in CHIT group (p < 0.05). Immunohistochemical reactions to S-100 in CHIT/PEMF were more positive than that in CHIT group. Whole body exposure to PEMF improved functional recovery and morphometric indices of sciatic nerve. Detailed mechanism of neuroprotective action remains to be investigated. PEMF combine with chitosan grafting could be considered as an effective, safe and tolerable treatment for peripheral nerve repair in clinical practice. Copyright © 2014 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JHyd..440...26F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JHyd..440...26F"><span>Solute transport in solution <span class="hlt">conduits</span> exhibiting multi-peaked breakthrough curves</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Field, Malcolm S.; Leij, Feike J.</p> <p>2012-05-01</p> <p>SummarySolute transport in karst aquifers is primarily constrained to solution <span class="hlt">conduits</span> where transport is rapid, turbulent, and relatively unrestrictive. Breakthrough curves generated from tracer tests are typically positively-skewed and may exhibit multiple peaks. In order to understand the circumstances under which multi-peaked positively skewed breakthrough curves occur, physical experiments utilizing single- and multiple-flow channels were conducted. Experiments also included waterfalls, short-term solute detention in pools, and flow obstructions. Results demonstrated that breakthrough curve skewness nearly always occurs to some degree but is magnified as immobile-flow regions are encountered. Multi-peaked breakthrough curves occurred when flow in the main channel became partially occluded from blockage in the main channel that forced divergence of solute into auxiliary channels and when waterfalls and detention in pools occurred. Currently, multi-peaked breakthrough curves are fitted by a multi-dispersion model in which a series of curves generated by the advection-dispersion equation are fitted to each measured peak by superimposing the measured breakthrough curve to obtain a combined model fit with a consequent set of estimated velocities and dispersions. In this paper, a dual-advection dispersion equation with first-order mass transfer between <span class="hlt">conduits</span> was derived. The dual-advection dispersion equation was then applied to the multi-peaked breakthrough curves obtained from the physical experiments in order to obtain some insight into the operative solute-transport processes through the acquisition of a consequent set of velocities, dispersions, and related parameters. Successful application of the dual-advection, dispersion equation to a tracer test that exhibited dual peaks for a karst aquifer known to consist of two connected but mostly separate <span class="hlt">conduits</span> confirmed the appropriateness of using a multi-dispersion type model when conditions warrant.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25853547','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25853547"><span>Orientated Guidance of Peripheral Nerve Regeneration Using <span class="hlt">Conduits</span> with a Microtube Array Sheet (MTAS).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Yueming; Wang, Wenjin; Wo, Yan; Gui, Ting; Zhu, Hao; Mo, Xiumei; Chen, Chien-Chung; Li, Qingfeng; Ding, Wenlong</p> <p>2015-04-29</p> <p>Material surface topography has been shown to affect the biological behavior of cells in vitro; however, the in vivo effect on peripheral nerve regeneration has not been explored. Here, we studied the potential of a microtube array sheet (MTAS) with a unique longitudinal surface topography to promote peripheral nerve regeneration efficiency, both in vivo and in vitro. Schwann cells, spinal cord motor neurons, and dorsal root ganglion neurons were seeded on the MTAS to study the effect of the construct on the biological properties and behaviors of neural cells. The MTAS guided the oriented migration of Schwann cells without affecting other critical biological properties, such as proliferation and neurotrophin expression. In addition, the MTAS guided the directed extension of neurites from both types of neurons. Next, we tested the capability of the MTAS to facilitate peripheral nerve regeneration by bridging a 10 mm sciatic nerve defect in rats with a nerve <span class="hlt">conduit</span> equipped with an MTAS lining. The MTAS significantly promoted peripheral nerve regeneration, as suggested by the greater fiber caliber in the midconduit and the greater abundance of fibers in nerve segment distal to the <span class="hlt">conduit</span>. Moreover, scanning electron microscopy (SEM) analysis suggested the orientated guidance of nerve regeneration by the MTAS, as indicated by the smaller eccentricity of the nerve fibers and the concordant arrangement of the collagen fiber in both the fibers and the matrix in the MTAS group. Our results collectively suggest that the <span class="hlt">conduits</span> with the MTAS developed in this study have significant potential for facilitating peripheral nerve regeneration by modifying critical biological behaviors and guiding orientated nerve growth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JVGR..320...19P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JVGR..320...19P"><span>A robotic approach to mapping post-eruptive volcanic fissure <span class="hlt">conduits</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Parcheta, Carolyn E.; Pavlov, Catherine A.; Wiltsie, Nicholas; Carpenter, Kalind C.; Nash, Jeremy; Parness, Aaron; Mitchell, Karl L.</p> <p>2016-06-01</p> <p>VolcanoBot was developed to map volcanic vents and their underlying <span class="hlt">conduit</span> systems, which are rarely preserved and generally inaccessible to human exploration. It uses a PrimeSense Carmine 1.09 sensor for mapping and carries an IR temperature sensor, analog distance sensor, and an inertial measurement unit (IMU) inside a protective shell. The first field test succeeded in collecting valuable scientific data but revealed several needed improvements, including more rugged cable connections and mechanical couplers, increased ground clearance, and higher-torque motors for uphill mobility. The second field test significantly improved on all of these aspects but it traded electrical ruggedness for reduced data collection speed. Data collected by the VolcanoBots, while intermittent, yield the first insights into the cm-scale geometry of volcanic fissures at depths of up to 25 m. VolcanoBot was deployed at the 1969 Mauna Ulu fissure system on Kīlauea volcano in Hawai'i. It collected first-of-its-kind data from inside the fissure system. We hypothesized that 1) fissure sinuosity should decrease with depth, 2) irregularity should be persistent with depth, 3) any blockages in the <span class="hlt">conduit</span> should occur at the narrowest points, and 4) the fissure should narrow with depth until it is too narrow for VolcanoBot to pass or is plugged with solidified lava. Our field campaigns did not span enough lateral or vertical area to test sinuosity. The preliminary data indicate that 1) there were many irregularities along fissures at depth, 2) blockages occurred, but not at obviously narrow locations, and 3) the <span class="hlt">conduit</span> width remained a consistent 0.4-0.5 m for most of the upper 10 m that we analyzed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23707012','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23707012"><span>Type I collagen nerve <span class="hlt">conduits</span> for median nerve repairs in the forearm.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dienstknecht, Thomas; Klein, Silvan; Vykoukal, Jody; Gehmert, Sebastian; Koller, Michael; Gosau, Martin; Prantl, Lukas</p> <p>2013-06-01</p> <p>To evaluate patients with median nerve damage in the distal forearm treated with type 1 collagen nerve <span class="hlt">conduits</span>. Nine patients with damage to the median nerve in the distal forearm underwent treatment with a type 1 collagen nerve <span class="hlt">conduit</span>. The nerve gaps ranged between 1 and 2 cm. An independent observer reexamined patients after treatment at a minimal follow-up of 14 months and a mean follow-up of 21 months. Residual pain was evaluated using a visual analog scale. Functional outcome was quantified by assessing static 2-point discrimination, nerve conduction velocity relative to the uninjured limb, and Disabilities of the Arm, Shoulder, and Hand outcome measure scoring. We also recorded quality of life measures including patients' perceived satisfaction with the results and return to work latency. We observed no implant-related complications. Of 9 patients, 7 were free of pain, and the mean visual analog scale was 0.6. The mean Disabilities of the Arm, Shoulder, and Hand score was 6. The static 2-point discrimination was less than 6 mm in 3 patients, between 6 and 10 mm in 4 patients, and over 10 mm in 2 patients. Six patients reached a status of M4 or higher. Eight patients were satisfied with the procedure and would undergo surgery again. This study indicates that purified type 1 bovine collagen <span class="hlt">conduits</span> are a practical and efficacious method for the repair of median nerves in the distal forearm. Therapeutic IV. Copyright © 2013 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24186149','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24186149"><span>Preparation and evaluation of novel nano-bioglass/gelatin <span class="hlt">conduit</span> for peripheral nerve regeneration.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Koudehi, Masoumeh Foroutan; Fooladi, Abbas Ali Imani; Mansoori, Kourosh; Jamalpoor, Zahra; Amiri, Afsaneh; Nourani, Mohammad Reza</p> <p>2014-02-01</p> <p>Peripheral nerves are exposed to physical injuries usually caused by trauma that may lead to a significant loss of sensory or motor functions and is considered as a serious health problem for societies today. This study was designed to develop a novel nano bioglass/gelatin <span class="hlt">conduit</span> (BGGC) for the peripheral nerve regeneration. The bioglass nanoparticles were prepared by sol-gel technique and characterized using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction analysis. The interfacial bonding interaction between the nano-bioglass and gelatin in the developed <span class="hlt">conduits</span> was assessed by FTIR. The surface morphology and pore size of the nanocomposite were investigated through scanning electron microscopy with the pore size of the <span class="hlt">conduits</span> being 10-40 μm. Biocompatibility was assessed by MTT assay which indicated the BGGC to have good cytocompatibility. The guidance channel was examined and used to regenerate a 10 mm gap in the right sciatic nerve of a male Wistar rat. Twenty rats were randomly divided into two experimental groups, one with the BGGC and the other being normal rats. The gastrocnemius muscle contractility was also examined at one, two and three months post-surgery in all groups using electromyography (EMAP). Histological and functional evaluation and the results obtained from electromyography indicated that at three months, nerve regeneration of the BGGC group was statistically equivalent to the normal group (p > 0.05). Our result suggests that the BGGC can be a suitable candidate for peripheral nerve repair.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5198762','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5198762"><span>Lower Extremity Arterial Bypass with Arm Vein <span class="hlt">Conduits</span> and Literature Review</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Park, Dae-Joon; Park, Yang-Jin; Yoon, Kyoung Won; Heo, Seon-Hee; Kim, Dong-Ik; Kim, Young-Wook</p> <p>2016-01-01</p> <p>Purpose: The superiority of autogenous vein <span class="hlt">conduits</span> is well known in lower extremity arterial bypass (LEAB). Among various alternative <span class="hlt">conduits</span> for LEAB, long-term results of arm vein grafts were investigated in this study. Materials and Methods: We retrospectively reviewed clinical characteristics of 28 patients who underwent infrainguinal LEAB with autogenous arm vein grafts at a single institute between January 2003 and December 2015. All procedures were performed in the absence of adequate saphenous veins. Graft patency was determined by periodic examinations with duplex ultrasonography. Results: Autologous arm vein grafts were implanted for 28 patients (mean age, 60.4±16.8 years; range, 20–82 years; male, 92.9%; atherosclerosis, 19 [67.9%]; and non-atherosclerotic disease 9 [32.1%] including 5 patients with Buerger’s disease). Source of arm vein were basilic 13 (46.4%), cephalic 4 (14.3%) and composition graft with other veins in 11 (39.3%) cases. The level of distal anastomosis was distributed as popliteal in 5 (17.9%), tibio-peroneal in 21 (75.0%) and inframalleolar artery in 2 (7.1%) cases. Mean duration of follow-up was 41.5±46.9 months (range, 1–138 months). Cumulative primary patency rates at 1, 3, and 5 years were 66.5%, 60.9% and 60.9%, respectively. Assisted-primary patency rates at 1, 3 and 5 years were 66.5%, 66.5% and 66.5%, respectively. Secondary patency rates at 1, 3 and 5 years were 70.8%, 70.8% and 70.8%, respectively. There was one limb amputation during the follow-up period. Conclusion: Arm veins are a useful alternative <span class="hlt">conduit</span> when great saphenous veins are not available during LEAB. PMID:28042555</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28042555','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28042555"><span>Lower Extremity Arterial Bypass with Arm Vein <span class="hlt">Conduits</span> and Literature Review.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Park, Dae-Joon; Park, Yang-Jin; Yoon, Kyoung Won; Heo, Seon-Hee; Kim, Dong-Ik; Kim, Young-Wook</p> <p>2016-12-01</p> <p>The superiority of autogenous vein <span class="hlt">conduits</span> is well known in lower extremity arterial bypass (LEAB). Among various alternative <span class="hlt">conduits</span> for LEAB, long-term results of arm vein grafts were investigated in this study. We retrospectively reviewed clinical characteristics of 28 patients who underwent infrainguinal LEAB with autogenous arm vein grafts at a single institute between January 2003 and December 2015. All procedures were performed in the absence of adequate saphenous veins. Graft patency was determined by periodic examinations with duplex ultrasonography. Autologous arm vein grafts were implanted for 28 patients (mean age, 60.4±16.8 years; range, 20-82 years; male, 92.9%; atherosclerosis, 19 [67.9%]; and non-atherosclerotic disease 9 [32.1%] including 5 patients with Buerger's disease). Source of arm vein were basilic 13 (46.4%), cephalic 4 (14.3%) and composition graft with other veins in 11 (39.3%) cases. The level of distal anastomosis was distributed as popliteal in 5 (17.9%), tibio-peroneal in 21 (75.0%) and inframalleolar artery in 2 (7.1%) cases. Mean duration of follow-up was 41.5±46.9 months (range, 1-138 months). Cumulative primary patency rates at 1, 3, and 5 years were 66.5%, 60.9% and 60.9%, respectively. Assisted-primary patency rates at 1, 3 and 5 years were 66.5%, 66.5% and 66.5%, respectively. Secondary patency rates at 1, 3 and 5 years were 70.8%, 70.8% and 70.8%, respectively. There was one limb amputation during the follow-up period. Arm veins are a useful alternative <span class="hlt">conduit</span> when great saphenous veins are not available during LEAB.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMDI31A4256K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMDI31A4256K"><span><span class="hlt">Conduit</span> entrainment surrounding sinking metal-silicate plumes during core formation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Klein, S. M.; Brand, D.; Weeraratne, D. S.</p> <p>2014-12-01</p> <p>Although the Earth today is segregated into two distinct compositional regions of a silicate mantle and metallic core, the process of differentiation from their original chondritic form is not clear. Continuous meteorite bombardment melted impactors and target bodies causing dissociation of metal from silicates which may have formed magma reservoirs or oceans. The heavy liquid metal phase will sink quickly through a silicate magma ocean and settle at the base as a metal pond. A high density metal pond will be unstable and is expected to sink as a Rayleigh-Taylor instability descending as liquid metal plumes to the core. Previous experiments have shown that lighter silicate material from the magma ocean becomes entrained as a <span class="hlt">conduit</span> that trails behind sinking metal diapirs. These silicates are then transported to the base of the mantle with implications for mantle and core composition. We perform laboratory fluid experiments which model this process of entrainment and differentiation using glass and gallium spheres in high viscosity liquid sucrose solutions. We use high speed photography and dye to visualize and measure <span class="hlt">conduit</span> formation and entrainment surrounding a descending sphere. Preliminary experiments indicate that the volume of material that surrounds a sphere is highest at the top of the box when the sphere begins its descent. As the sphere sinks, the entrainment of dyed fluid around the sphere decreases exponentially with falling distance. We suggest this is the result of drag forces acting on walls of the <span class="hlt">conduit</span>. The volume of entrained material reduces by 80% in the upper 1/3 of the drop trajectory. As much as 8-10% of the original fluid volume is carried to the base of the box and will segregate from the sphere or diffuse after it settles. Higher viscosity fluids are observed to entrain more material on average compared to lower viscosity fluids. These results have important implications for delivery of silicate materials to the base of the mantle</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/871940','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/871940"><span>Device and method for measuring multi-phase fluid flow and density of fluid in a <span class="hlt">conduit</span> having a gradual bend</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Ortiz, Marcos German; Boucher, Timothy J.</p> <p>1998-01-01</p> <p>A system for measuring fluid flow in a <span class="hlt">conduit</span> having a gradual bend or arc, and a straight section. The system includes pressure transducers, one or more disposed in the <span class="hlt">conduit</span> on the outside of the arc, and one disposed in the <span class="hlt">conduit</span> in a straight section thereof. The pressure transducers measure the pressure of fluid in the <span class="hlt">conduit</span> at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the <span class="hlt">conduit</span>. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the <span class="hlt">conduit</span> elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/675796','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/675796"><span>Device and method for measuring multi-phase fluid flow and density of fluid in a <span class="hlt">conduit</span> having a gradual bend</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Ortiz, M.G.; Boucher, T.J.</p> <p>1998-10-27</p> <p>A system is described for measuring fluid flow in a <span class="hlt">conduit</span> having a gradual bend or arc, and a straight section. The system includes pressure transducers, one or more disposed in the <span class="hlt">conduit</span> on the outside of the arc, and one disposed in the <span class="hlt">conduit</span> in a straight section thereof. The pressure transducers measure the pressure of fluid in the <span class="hlt">conduit</span> at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the <span class="hlt">conduit</span>. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the <span class="hlt">conduit</span> elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow. 1 fig.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1175419','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1175419"><span>Systems and methods for coating <span class="hlt">conduit</span> interior surfaces utilizing a thermal spray gun with extension arm</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Moore, Karen A.; Zatorski, Raymond A.</p> <p>2005-07-12</p> <p>Systems and methods for applying a coating to an interior surface of a <span class="hlt">conduit</span>. In one embodiment, a spray gun configured to apply a coating is attached to an extension arm which may be inserted into the bore of a pipe. The spray gun may be a thermal spray gun adapted to apply a powder coating. An evacuation system may be used to provide a volume area of reduced air pressure for drawing overspray out of the pipe interior during coating. The extension arm as well as the spray gun may be cooled to maintain a consistent temperature in the system, allowing for more consistent coating.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/917199','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/917199"><span>Methods for coating <span class="hlt">conduit</span> interior surfaces utilizing a thermal spray gun with extension arm</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Moore, Karen A.; Zatorski, Raymond A.</p> <p>2007-10-02</p> <p>Systems and methods for applying a coating to an interior surface of a <span class="hlt">conduit</span>. In one embodiment, a spray gun configured to apply a coating is attached to an extension arm which may be inserted into the bore of a pipe. The spray gun may be a thermal spray gun adapted to apply a powder coating. An evacuation system may be used to provide a volume area of reduced air pressure for drawing overspray out of the pipe interior during coating. The extension arm as well as the spray gun may be cooled to maintain a consistent temperature in the system, allowing for more consistent coating.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12405605','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12405605"><span>A dual-pressure boundary condition for use in simulations of bifurcating <span class="hlt">conduits</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gin, Ron; Straatman, Anthony G; Steinman, David A</p> <p>2002-10-01</p> <p>A dual-pressure boundary condition has been developed for computational modelling of bifurcating <span class="hlt">conduits</span>. The condition involves the imposition of a constant pressure on one branch while adjusting iteratively the pressure on the other branch until the desired flow division is obtained. The dual-pressure condition eliminates the need for specifying fully-developed flow conditions, which thereby enables significant reduction of the outlet branch lengths. The dual-pressure condition is suitable for both steady and time-periodic simulations of laminar or turbulent flows.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/15003852','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/15003852"><span>ITER Model Coil Tests Overview: Nb3Sn Strand Properties in Cable-in-<span class="hlt">Conduit</span>-Conductors</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Martovetsky, N N</p> <p>2003-04-14</p> <p>During the ITER Model Coil Program two large coils and three Insert coils were built and tested. The test campaigns provided very valuable data on the Conductor in <span class="hlt">Conduit</span> Cable (CICC) properties. The tests showed that the Nb3Sn strands in CICC behave differently than so-called witness strands, which underwent the same heat treatment. The paper describes Volt-temperature characteristics (VTC) and Volt-Ampere characteristics (VAC) measured in the tests, presents comparisons with the witness strands, and interprets the test results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/426003','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/426003"><span>Pressure drop measurements of prototype NET and CEA cable-in-<span class="hlt">conduit</span> conductors (CICCs)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Maekawa, R.; Smith, M.R.; Van Sciver, S.W.</p> <p>1996-12-31</p> <p>The pressure drop of two prototype cable-in-<span class="hlt">conduit</span> conductors (CICCs) were measured. The NET conductor is a conventional type CICC, while the CEA conductor has a central flow channel to reduce hydraulic impedance. The pressure drop measurements were conducted with helium at temperatures ranging from 2K to 4.7K, and pressure from the saturated vapor pressure to in excess of 3 bar. Computer image analysis was used to estimate the flow cross sectional area and wetted perimeter of the conductors. The data are expressed in terms of a classical friction factor, and compared with precious experimental results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.V21B4747M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.V21B4747M"><span>Oxidation of shallow <span class="hlt">conduit</span> magma: Insight from μ-XANES analysis on volcanic ash particle</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miwa, T.; Ishibashi, H.; Iguchi, M.</p> <p>2014-12-01</p> <p>Redox state of magma is important to understand dynamics of volcanic eruptions because magma properties such as composition of degassed volatiles, stability field of minerals, and rheology of magma depend on redox state. To evaluate redox state of magma, Fe3+/ΣFe ratio [= Fe3+/( Fe3++ Fe2+)] of volcanic glass has been measured non-destructively by Fe-K edge μ-XANES (micro X-ray Absorption Near Edge Structure) spectroscopy (e.g., Cottrell and Kelly, 2011). We performed textural, compositional, and Fe-K edge μ-XANES analyses on volcanic ash to infer oxidation process of magma at shallow <span class="hlt">conduit</span> during eruption at Bromo Volcano, Indonesia. The volcanic ash particles were collected in 24th March 2011 by real-time sampling from ongoing activity. The activity was characterized by strombolian eruption showing magma head ascended to near the ground surface. The ash sample contains two type of volcanic glasses named as Brown and Black glasses (BrG and BlG), based on their color. Textual analysis shows microlite crystallinities are same in the two type of glasses, ranging from 0 to 3 vol.%. EPMA analyses show that all of the glasses have almost identical andesitic composition with SiO2 = 60 wt.%. In contrast, Fe-K edge μ-XANES spectra with the analytical method by Ishibashi et al. (in prep) demonstrate that BrG (Fe3+/ΣFe = 0.20-0.26) is more oxidized than BlG (Fe3+/ΣFe = 0.32-0.60). From combination of the glass composition, the measured Fe3+/ΣFe ratio and 1060 degree C of temperature (Kress and Carmichael, 1991), the oxygen fugacities are estimated to be NNO and NNO+4 for BrG and BlG, respectively. The volcanic glasses preserve syn-eruptive physicochemical conditions by rapid quenching due to their small size ranging from 125 to 250 μm. Our results demonstrate that BrG and BlG magmas are textually and chemically identical but their redox conditions are different at the eruption. The oxidation of magma can be caused by following two processes; 1) diffusive transport</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007GeoJI.171.1406H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007GeoJI.171.1406H"><span>The influence of viscous and latent heating on crystal-rich magma flow in a <span class="hlt">conduit</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hale, Alina J.; Wadge, Geoff; Mühlhaus, Hans B.</p> <p>2007-12-01</p> <p>The flow dynamics of crystal-rich high-viscosity magma is likely to be strongly influenced by viscous and latent heat release. Viscous heating is observed to play an important role in the dynamics of fluids with temperature-dependent viscosities. The growth of microlite crystals and the accompanying release of latent heat should play a similar role in raising fluid temperatures. Earlier models of viscous heating in magmas have shown the potential for unstable (thermal runaway) flow as described by a Gruntfest number, using an Arrhenius temperature dependence for the viscosity, but have not considered crystal growth or latent heating. We present a theoretical model for magma flow in an axisymmetric <span class="hlt">conduit</span> and consider both heating effects using Finite Element Method techniques. We consider a constant mass flux in a 1-D infinitesimal <span class="hlt">conduit</span> segment with isothermal and adiabatic boundary conditions and Newtonian and non-Newtonian magma flow properties. We find that the growth of crystals acts to stabilize the flow field and make the magma less likely to experience a thermal runaway. The additional heating influences crystal growth and can counteract supercooling from degassing-induced crystallization and drive the residual melt composition back towards the liquidus temperature. We illustrate the models with results generated using parameters appropriate for the andesite lava dome-forming eruption at Soufrière Hills Volcano, Montserrat. These results emphasize the radial variability of the magma. Both viscous and latent heating effects are shown to be capable of playing a significant role in the eruption dynamics of Soufrière Hills Volcano. Latent heating is a factor in the top two kilometres of the <span class="hlt">conduit</span> and may be responsible for relatively short-term (days) transients. Viscous heating is less restricted spatially, but because thermal runaway requires periods of hundreds of days to be achieved, the process is likely to be interrupted. Our models show that</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28764245','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28764245"><span>Bilateral Staghorn Calculus with Forgotten Double J Stent in Ileal <span class="hlt">Conduit</span> Patient - A Rare Urological Challenge.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gupta, Rupesh; Dey, Ranjan Kumar; Sharma, Rakesh; Gupta, Sweta</p> <p>2017-06-01</p> <p>Forgotten DJ stent associated stone formation is not an uncommon entity. Here we are reporting the uncommon case of bilateral staghorn calculus due to forgotten DJ stent who had undergone radical cystectomy with ileal <span class="hlt">conduit</span> diversion six years back. Management of these cases is a challenging urological situation due to inaccessible ureteric orifices. Patient was successfully treated with minimally invasive therapy in the form of combined bilateral PCNL (Percutaneous Nephrolithotomy) and ESWL (Extracorporeal Shock Wave Lithotripsy) therapy. The purpose of reporting this case is to highlight the grave consequences of a forgotten DJ stent and to discuss the difficulties encountered during the surgical steps of stone removal.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=287818','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=287818"><span>POST-TRAUMATIC APICAL LEFT VENTRICULAR ANEURYSM IN A PATIENT WITH LEFT VENTRICULAR APICAL-ABDOMINAL AORTIC <span class="hlt">CONDUIT</span>: CASE PRESENTATION</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ugorji, Clement C.; Cooley, Denton A.; Norman, John C.</p> <p>1979-01-01</p> <p>A patient with a small aortic annulus had an apico-aortic <span class="hlt">conduit</span> implanted for aortic stenosis approximately three years before being admitted to our institution. Four months after sustaining a steering wheel injury to the chest, he developed chest pain and palpitations. X-ray films and left ventriculograms revealed a large apical aneurysm of unknown duration. At surgery, it was noted that the proximal portion of the <span class="hlt">conduit</span> had been sewn directly to the myocardium without the use of a rigid or soft apical outlet prosthesis incorporating a sewing ring. The aneurysm was resected along with a small proximal segment of the <span class="hlt">conduit</span> graft. A polished Pyrolite® rigid inlet tube with a sewing ring and graft extension was inserted into the residual left ventricular apex, and continuity was reestablished with the abdominal segment of the <span class="hlt">conduit</span>. It is postulated that the aneurysm was caused by either the direct anastomosis of the fabric graft to the apical myocardium at the original operation (with subsequent disruption and aneurysm formation prior to the steering wheel injury), or was the result of fixation of the heart at the diaphragm by the <span class="hlt">conduit</span>, with increased vulnerability to deceleration injury at the direct left ventricular apex myocardium-fabric graft site. Images PMID:15216296</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70000346','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70000346"><span>Physical rock properties in and around a <span class="hlt">conduit</span> zone by well-logging in the Unzen Scientific Drilling Project, Japan</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Ikeda, R.; Kajiwara, T.; Omura, K.; Hickman, S.</p> <p>2008-01-01</p> <p>The objective of the Unzen Scientific Drilling Project (USDP) is not only to reveal the structure and eruption history of the Unzen volcano but also to clarify the ascent and degassing mechanisms of the magma <span class="hlt">conduit</span>. <span class="hlt">Conduit</span> drilling (USDP-4) was conducted in 2004, which targeted the magma <span class="hlt">conduit</span> for the 1990-95 eruption. The total drilled length of USDP-4 was 1995.75??m. Geophysical well logging, including resistivity, gamma-ray, spontaneous potential, sonic-wave velocity, density, neutron porosity, and Fullbore Formation MicroImager (FMI), was conducted at each drilling stage. Variations in the physical properties of the rocks were revealed by the well-log data, which correlated with not only large-scale formation boundaries but also small-scale changes in lithology. Such variations were evident in the lava dike, pyroclastic rocks, and breccias over depth intervals ranging from 1 to 40??m. These data support previous models for structure of the lava <span class="hlt">conduit</span>, in that they indicate the existence of alternating layers of high-resistivity and high P-wave velocity rocks corresponding to the lava dikes, in proximity to narrower zones exhibiting high porosity, low resistivity, and low P-wave velocity. These narrow, low-porosity zones are presumably higher in permeability than the adjacent rocks and may form preferential <span class="hlt">conduits</span> for degassing during magma ascent. ?? 2008 Elsevier B.V.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4237645','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4237645"><span>Brilliant Blue FCF as an Alternative Dye for Saphenous Vein Graft Marking Effect on <span class="hlt">Conduit</span> Function</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Voskresensky, Igor V.; Wise, Eric S.; Hocking, Kyle M.; Li, Fan Dong; Osgood, Michael J.; Komalavilas, Padmini; Brophy, Colleen; Cheung-Flynn, Joyce</p> <p>2014-01-01</p> <p> −27.9% [3.7%] for HSVs after manipulation; P < .001). In rat inferior venae cavae, FCF inhibited the contraction induced by the P2X7 receptor agonist 2′(3′)-O-(4-benzoyl)benzoyl-adenosine-5′-triphosphate (mean [SEM], 14.8% [2.2%] vs 6.5% [1.8%]; P = .02) to an extent similar to the P2X7 receptor antagonist oxidized adenosine triphosphate (mean [SEM], 5.0% [0.9%]; P < .02 vs <span class="hlt">control</span>) or the pannexin hemichannel inhibitor probenecid (mean [SEM], 7.3% [1.6%] and 4.7% [0.9%] for 0.5mM and 2mM, respectively; P < .05). CONCLUSIONS AND RELEVANCE Treatment with FCF did not impair endothelial or smooth muscle function in HSVs. Brilliant blue FCF enhanced endothelial-dependent relaxation, restored smooth muscle function, and prevented intimal hyperplasia in HSVs in organ culture. These pharmacological properties of FCF may be due to P2X7 receptor or pannexin channel inhibition. Brilliant blue FCF is an alternative, nontoxic marking dye that may improve HSV <span class="hlt">conduit</span> function and decrease intimal hyperplasia. PMID:25251505</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT........89H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT........89H"><span>Computational modeling of lava domes using particle dynamics to investigate the effect of <span class="hlt">conduit</span> flow mechanics on flow patterns</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Husain, Taha Murtuza</p> <p></p> <p>Large (1--4 x 106 m3) to major (> 4 x 106 m3) dome collapses for andesitic lava domes such as Soufriere Hills Volcano, Montserrat are observed for elevated magma discharge rates (6--13 m3/s). The gas rich magma pulses lead to pressure build up in the lava dome that result in structural failure of the over steepened canyon-like walls which may lead to rockfall or pyroclastic flow. This indicates that dome collapse intimately related to magma extrusion rate. Variation in magma extrusion rate for open-system magma chambers is observed to follow alternating periods of high and low activity. Periodic behavior of magma exhibits a rich diversity in the nature of its eruptive history due to variation in magma chamber size, total crystal content, linear crystal growth rate and magma replenishment rate. Distinguished patterns of growth were observed at different magma flow rates ranging from endogenous to exogenous dome growth for magma with varying strengths. Determining the key parameters that <span class="hlt">control</span> the transition in flow pattern of the magma during its lava dome building eruption is the main focus. This dissertation examines the mechanical effects on the morphology of the evolving lava dome on the extrusion of magma from a central vent using a 2D particle dynamics model. The particle dynamics model is coupled with a <span class="hlt">conduit</span> flow model that incorporates the kinetics of crystallization and rheological stiffening to investigate important mechanisms during lava dome building eruptions. Chapter I of this dissertation explores lava dome growth and failure mechanics using a two-dimensional particle-dynamics model. The model follows the evolution of fractured lava, with solidification driven by degassing induced crystallization of magma. The particle-dynamics model emulates the natural development of dome growth and rearrangement of the lava dome which is difficult in mesh-based analyses due to mesh entanglement effects. The deformable talus evolves naturally as a frictional</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24334142','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24334142"><span>Three-dimensional printed trileaflet valve <span class="hlt">conduits</span> using biological hydrogels and human valve interstitial cells.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Duan, B; Kapetanovic, E; Hockaday, L A; Butcher, J T</p> <p>2014-05-01</p> <p>Tissue engineering has great potential to provide a functional de novo living valve replacement, capable of integration with host tissue and growth. Among various valve <span class="hlt">conduit</span> fabrication techniques, three-dimensional (3-D) bioprinting enables deposition of cells and hydrogels into 3-D constructs with anatomical geometry and heterogeneous mechanical properties. Successful translation of this approach, however, is constrained by the dearth of printable and biocompatible hydrogel materials. Furthermore, it is not known how human valve cells respond to these printed environments. In this study, 3-D printable formulations of hybrid hydrogels are developed, based on methacrylated hyaluronic acid (Me-HA) and methacrylated gelatin (Me-Gel), and used to bioprint heart valve <span class="hlt">conduits</span> containing encapsulated human aortic valvular interstitial cells (HAVIC). Increasing Me-Gel concentration resulted in lower stiffness and higher viscosity, facilitated cell spreading, and better maintained HAVIC fibroblastic phenotype. Bioprinting accuracy was dependent upon the relative concentrations of Me-Gel and Me-HA, but when optimized enabled the fabrication of a trileaflet valve shape accurate to the original design. HAVIC encapsulated within bioprinted heart valves maintained high viability, and remodeled the initial matrix by depositing collagen and glyosaminoglycans. These findings represent the first rational design of bioprinted trileaflet valve hydrogels that regulate encapsulated human VIC behavior. The use of anatomically accurate living valve scaffolds through bioprinting may accelerate understanding of physiological valve cell interactions and progress towards de novo living valve replacements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/837117','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/837117"><span>Low-quality habitat corridors as movement <span class="hlt">conduits</span> for two butterfly species.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Haddad, Nick, M.; Tewksbury, Joshua, J.</p> <p>2005-01-01</p> <p>Haddad, Nick, M, and Joshua J. Tewksbury. Low-quality habitat corridors as movement <span class="hlt">conduits</span> for two butterfly species. Ecol. Apps. 15(1):250-257. Abstract. Corridors are a primary conservation tool to increase connectivity, promote individual movement, and increase gene flow among populations in fragmented landscapes. The establishment of effective conservation corridors will depend on constructing or pre-serving connecting habitat that attracts dispersing individuals. Yet, it remains unclear whether corridors must necessarily be composed of high-quality habitat to be effective and promote dispersal and gene flow. We address this issue with two mobile, open-habitat butterfly species, Junonia coenia HuÈbner and Euptoieta claudia Cramer. Using experimental landscapes created explicitly to examine the effects of corridors on dispersal rates, we show that open-habitat corridors can serve as dispersal <span class="hlt">conduits</span> even when corridors do not support resident butterfly populations. Both butterfly species were rare near forest edges and equally rare in narrow corridors, yet both species dispersed more often between patches connected by these corridors than between isolated patches. At least for species that can traverse corridors within a generation, corridor habitat may be lower in quality than larger patches and still increase dispersal and gene flow. For these species, abundance surveys may not accurately represent the conservation value of corridors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1361612-cold-work-study-modified-alloy-iter-tf-coil-conduit','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1361612-cold-work-study-modified-alloy-iter-tf-coil-conduit"><span>Cold work study on a 316LN modified alloy for the ITER TF coil <span class="hlt">conduit</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Walsh, Robert; Toplosky, V. J.; McRae, D. M.; ...</p> <p>2012-06-01</p> <p>The primary structural component of the cable-in-<span class="hlt">conduit</span> conductor (CICC) magnets, such as the ITER TF coils is the <span class="hlt">conduit</span>. This function creates requirements for 4 K strength, toughness, fatigue crack resistance, and ductility after exposure to the superconductor's reaction heat treatment. The tensile ductility of a steel is a quality factor related to fatigue and fracture resistance that can be evaluated more economically with tensile tests rather than fatigue and fracture tests. We subject 316LN modified base metal and welds to a range of cold work from 0% to 20% and a subsequent Nb3Sn reaction heat treatment to evaluate themore » effects on the tensile properties. With the addition of cold work, the 4 K yield strength increases while tensile elongation decreases in both the base metal and weld. Our results are compared to previously published data on the same alloy to evaluate the use of tensile ductility parameters as a materials qualification specification in magnet design.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5482720','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5482720"><span>Actively evolving subglacial <span class="hlt">conduits</span> and eskers initiate ice shelf channels at an Antarctic grounding line</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Drews, R.; Pattyn, F.; Hewitt, I. J.; Ng, F. S. L.; Berger, S.; Matsuoka, K.; Helm, V.; Bergeot, N.; Favier, L.; Neckel, N.</p> <p>2017-01-01</p> <p>Ice-shelf channels are long curvilinear tracts of thin ice found on Antarctic ice shelves. Many of them originate near the grounding line, but their formation mechanisms remain poorly understood. Here we use ice-penetrating radar data from Roi Baudouin Ice Shelf, East Antarctica, to infer that the morphology of several ice-shelf channels is seeded upstream of the grounding line by large basal obstacles indenting the ice from below. We interpret each obstacle as an esker ridge formed from sediments deposited by subglacial water <span class="hlt">conduits</span>, and calculate that the eskers' size grows towards the grounding line where deposition rates are maximum. Relict features on the shelf indicate that these linked systems of subglacial <span class="hlt">conduits</span> and ice-shelf channels have been changing over the past few centuries. Because ice-shelf channels are loci where intense melting occurs to thin an ice shelf, these findings expose a novel link between subglacial drainage, sedimentation and ice-shelf stability. PMID:28485400</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3773896','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3773896"><span>Robotic Intracorporeal Ileal <span class="hlt">Conduit</span> Formation: Initial Experience from a Single UK Centre</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bishop, Conrad V.; Adshead, James M.</p> <p>2013-01-01</p> <p>Objectives. To describe our technique of robotic intracorporeal ileal <span class="hlt">conduit</span> formation (RICIC) during robotic-assisted radical cystectomy (RARC). To report our initial results of this new procedure. Patients and Methods. Seven male and one female patients underwent RARC with RICIC over a six-month period. Demographic, operative, and outcome data was collected prospectively. Median patient age was 75 years (range 62–78 years). Median followup was 9 months (range 7–14 months). Results. RARC with RICIC was performed successfully in all eight patients. The median total operating time was 360 minutes (range 310–440 minutes) with a median blood loss of 225 mL (range 50–1000 mL). The median length of stay was nine days (range 6–34 days). Four patients (50%) were discharged within seven days. Four patients (50%) experienced one or more complications. This included two Clavien I complications, two Clavien II complications, and two Clavien III complications. Two patients (25%) required transfusion of two units each. To date, there have been no complications associated with the ileal <span class="hlt">conduit</span>. Conclusion. Whilst being technically challenging, this procedure is safe, feasible, and reproducible. Patients who avoid complication show potential for rapid recovery and early discharge. PMID:24072995</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3976766','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3976766"><span>3D Printed Trileaflet Valve <span class="hlt">Conduits</span> Using Biological Hydrogels and Human Valve Interstitial Cells</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Duan, Bin; Kapetanovic, Edi; Hockaday, Laura A.; Butcher, Jonathan T.</p> <p>2014-01-01</p> <p>Tissue engineering has great potential to provide a functional de novo living valve replacement capable of integration with host tissue and growth. Among various valve <span class="hlt">conduit</span> fabrication techniques, 3D bioprinting enables deposition of cells and hydrogels into 3D constructs with anatomical geometry and heterogeneous mechanical properties. Successful translation of this approach is however constrained by the dearth of printable and biocompatible hydrogel materials. Furthermore, it is not known how human valve cells respond to these printed environments. In this study, we develop 3D printable formulations of hybrid hydrogels based on methacrylated hyaluronic acid (Me-HA) and methacrylated gelatin (Me-Gel), and utilize them to bioprint heart valve <span class="hlt">conduits</span> containing encapsulated human aortic valvular interstitial cells (HAVIC). Increasing Me-Gel concentration resulted in lower stiffness and higher viscosity, facilitated cell spreading, and better maintained HAVIC fibroblastic phenotype. Bioprinting accuracy was dependent upon the relative concentrations of Me-Gel and Me-HA, but when optimized enabled the fabrication of a trileaflet valve shape accurate to the original design. HAVIC encapsulated within bioprinted heart valves maintained high viability, and remodeled the initial matrix by depositing collagen and glyosaminoglycans. These findings represent the first rational design of bioprinted trileaflet valve hydrogels that regulate encapsulated human VIC behavior. The use of anatomically accurate living valve scaffolds through bioprinting may accelerate our understanding of physiological valve cell interactions and our progress towards de novo living valve replacements. PMID:24334142</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1361612','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1361612"><span>Cold work study on a 316LN modified alloy for the ITER TF coil <span class="hlt">conduit</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Walsh, Robert; Toplosky, V. J.; McRae, D. M.; Han, K.; Martovetsky, N. N.</p> <p>2012-06-01</p> <p>The primary structural component of the cable-in-<span class="hlt">conduit</span> conductor (CICC) magnets, such as the ITER TF coils is the <span class="hlt">conduit</span>. This function creates requirements for 4 K strength, toughness, fatigue crack resistance, and ductility after exposure to the superconductor's reaction heat treatment. The tensile ductility of a steel is a quality factor related to fatigue and fracture resistance that can be evaluated more economically with tensile tests rather than fatigue and fracture tests. We subject 316LN modified base metal and welds to a range of cold work from 0% to 20% and a subsequent Nb<sub>3</sub>Sn reaction heat treatment to evaluate the effects on the tensile properties. With the addition of cold work, the 4 K yield strength increases while tensile elongation decreases in both the base metal and weld. Our results are compared to previously published data on the same alloy to evaluate the use of tensile ductility parameters as a materials qualification specification in magnet design.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=324610','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=324610"><span>Preliminary Experience with GORE-TEX® Grafting for Right Ventricle-Pulmonary Artery <span class="hlt">Conduits</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Molina, J. Ernesto</p> <p>1986-01-01</p> <p>A consecutive series of 12 patients between the ages of 6½ and 37 years underwent implantation of venous ventricle-pulmonary artery <span class="hlt">conduits</span>. GORE-TEX material without prosthetic valves was used. Four patients had L-transposition of the great vessels with ventricular septal defect (VSD) and pulmonary stenosis; four had tetralogy of Fallot with pulmonary atresia; and one had double outlet right ventricle, pulmonary stenosis, and a complete form of A-V canal. Two patients had D-transposition of the great arteries, VSD, and pulmonary stenosis; and one patient had L-transposition of the great arteries and isolated pulmonary stenosis. All patients had low pulmonary resistance and pressures. The technique for implanting this noncrimped type of prosthesis is described in detail. Follow-up ranged from 2 months to 5½ years. GORE-TEX offers a good choice of material for the construction of this type of <span class="hlt">conduit</span> to prevent pseudointima formation and obstruction, which is often observed in woven Dacron grafts. PMID:15226844</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21421408','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21421408"><span>Refilling embolized xylem <span class="hlt">conduits</span>: is it a matter of phloem unloading?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nardini, Andrea; Lo Gullo, Maria A; Salleo, Sebastiano</p> <p>2011-04-01</p> <p>Long-distance water transport in plants relies on negative pressures established in continuous water columns in xylem <span class="hlt">conduits</span>. Water under tension is in a metastable state and is prone to cavitation and embolism, which leads to loss of hydraulic conductance, reduced productivity and eventually plant death. Experimental evidence suggests that plants can repair embolized xylem by pushing water from living vessel-associated cells into the gas-filled <span class="hlt">conduit</span> lumina. Most surprisingly, embolism refilling is known to occur even when the bulk of still functioning xylem is under tension, a finding that is in seemingly contradiction to basic principles of thermodynamics. This review summarizes our current understanding of xylem refilling processes and speculates that embolism repair under tension can be envisioned as a particular case of phloem unloading, as suggested by several events and components of embolism repair, typically involved in phloem unloading mechanisms. Far from being a challenge to irreversible thermodynamics, embolism refilling is emerging as a finely regulated vital process essential for plant functioning under different environmental stresses. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1341685-mouthpart-conduit-sizes-fluid-feeding-insects-determine-ability-feed-from-pores','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1341685-mouthpart-conduit-sizes-fluid-feeding-insects-determine-ability-feed-from-pores"><span>Mouthpart <span class="hlt">conduit</span> sizes of fluid-feeding insects determine the ability to feed from pores</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Lehnert, Matthew S.; Bennett, Andrew; Reiter, Kristen E.; ...</p> <p>2017-01-04</p> <p>Fluid-feeding insects, such as butterflies, moths, and flies (20% of all animal species), are faced with the common selection pressure of having to remove and feed on trace amounts of fluids from porous surfaces. Insects able to acquire fluids that are confined to pores during drought conditions would have an adaptive advantage and increased fitness over other individuals. Here we performed feeding trials using solutions with magnetic nanoparticles to show that butterflies and flies have mouthparts adapted to pull liquids from porous surfaces using capillary action as the governing principle. In addition, the ability to feed on the liquids collectedmore » from pores depends on a relationship between the diameter of the mouthpart <span class="hlt">conduits</span> and substrate pore size diameter; insects with mouthpart <span class="hlt">conduit</span> diameters larger than the pores cannot successfully feed, thus there is a limiting substrate pore size from which each species can acquire liquids for fluid uptake. In conclusion, given that natural selection independently favored mouthpart architectures that support these methods of fluid uptake (Diptera and Lepidoptera share a common ancestor 280 mya that had chewing mouthparts), we suggest that the convergence of this mechanism advocates this as an optimal strategy for pulling trace amounts of fluids from porous surfaces.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1816389F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1816389F"><span>A tool for computing time-dependent permeability reduction of fractured volcanic <span class="hlt">conduit</span> margins.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Farquharson, Jamie; Wadsworth, Fabian; Heap, Michael; Baud, Patrick</p> <p>2016-04-01</p> <p>Laterally-oriented fractures within volcanic <span class="hlt">conduit</span> margins are thought to play an important role in tempering eruption explosivity by allowing magmatic volatiles to outgas. The permeability of a fractured <span class="hlt">conduit</span> margin - the equivalent permeability - can be modelled as the sum of permeability contributions of the edifice host rock and the fracture(s) within it. We present here a flexible MATLAB® tool which computes the time-dependent equivalent permeability of a volcanic <span class="hlt">conduit</span> margin containing ash-filled fractures. The tool is designed so that the end-user can define a wide range of input parameters to yield equivalent permeability estimates for their application. The time-dependence of the equivalent permeability is incorporated by considering permeability decrease as a function of porosity loss in the ash-filled fractures due to viscous sintering (after Russell and Quane, 2005), which is in turn dependent on the depth and temperature of each fracture and the crystal-content of the magma (all user-defined variables). The initial viscosity of the granular material filling the fracture is dependent on the water content (Hess and Dingwell, 1996), which is computed assuming equilibrium depth-dependent water content (Liu et al., 2005). Crystallinity is subsequently accounted for by employing the particle-suspension rheological model of Mueller et al. (2010). The user then defines the number of fractures, their widths, and their depths, and the lengthscale of interest (e.g. the length of the <span class="hlt">conduit</span>). Using these data, the combined influence of transient fractures on the equivalent permeability of the <span class="hlt">conduit</span> margin is then calculated by adapting a parallel-plate flow model (developed by Baud et al., 2012 for porous sandstones), for host rock permeabilities from 10-11 to 10-22 m2. The calculated values of porosity and equivalent permeability with time for each host rock permeability is then output in text and worksheet file formats. We introduce two dimensionless</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24041294','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24041294"><span>Behavioral evaluation of regenerated rat sciatic nerve by a nanofibrous PHBV <span class="hlt">conduit</span> filled with Schwann cells as artificial nerve graft.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Biazar, Esmaeil; Heidari Keshel, Saeed; Pouya, Majid</p> <p>2013-10-01</p> <p>The aim of this study is to develop a nanofibrous polymeric nerve <span class="hlt">conduit</span> with Schwann cells (SCs) and to evaluate its efficiency on the promotion of functional and locomotive activities in rats. The <span class="hlt">conduits</span> were implanted into a 30-mm gap in the sciatic nerves of the rats. Four months after surgery, the rats were monitored and evaluated by behavioral analyses such as toe out angle, toe spreading analysis, walking track analysis, extensor postural thrust, open-field analysis, swimming test and nociceptive function, four months post surgery. Four months post-operatively, the results from behavioral analyses demonstrated that in the grafted groups especially in the grafted group with SCs, the rat sciatic nerve trunk had been reconstructed with functional recovery such as walking, swimming and recovery of nociceptive function. This study proves the feasibility of artificial <span class="hlt">conduit</span> with SCs for nerve regeneration by bridging a longer defect in the rat model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016BVol...78...50N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016BVol...78...50N"><span>The earliest open <span class="hlt">conduit</span> eruptive center of the Etnean region: evidence from aeromagnetic, geophysical, and geological data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nicolosi, Iacopo; D'Ajello Caracciolo, Francesca; Branca, Stefano; Ferlito, Carmelo; Chiappini, Massimo</p> <p>2016-07-01</p> <p>At Mount Etna, the present-day active volcano is an open <span class="hlt">conduit</span> structure characterized by continuous eruptive activity. Such conditions have been thought unique in the evolution of the Etnean volcano as well as in the Mediterranean region. However, a review study of available geophysical data and models, combined with geological records, petrographic and geochemical considerations, has led us to consider that a large area of about 28 km2 located in Val Calanna, on the eastern side of Valle del Bove, can be interpreted as the site of an old open <span class="hlt">conduit</span> volcano. A dyke swarm outcrops in the area, whose deep alteration and fumarolization can be attributed to the sustained passage of volcanic gases over long periods. Radiometric dating yields an age of about 129 ka. This finding sheds new light on the evolution of Mount Etna volcano, indicating that the tectonic conditions leading to an open <span class="hlt">conduit</span> volcano must also have been active in the past.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27657936','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27657936"><span>A Nerve <span class="hlt">Conduit</span> Containing a Vascular Bundle and Implanted With Bone Marrow Stromal Cells and Decellularized Allogenic Nerve Matrix.</span></a></p> <p><a target="_bla