WorldWideScience

Sample records for vapor conduit means

  1. Quench detection by fluid dynamic means in cable-in-conduit superconductors

    Science.gov (United States)

    Dresner, L.

    1987-06-01

    The tight confinement of the helium in cable-in-conduit superconductors creates protection problems because of the substantial pressure rise that can occur during a quench. But the same pressure rise offers the useful possibility of a non-electrical means of detecting incipient quenches by monitoring the outflow from the various hydraulic paths of the magnet. If the method is to work, the signal must be large enough to be detected unambiguously at an early enough time, and the signal must not depend too strongly on the length, Joule power density, or rate of growth of the initial normal zone (because these things are not entirely within our control). This paper explores by calculation the degree to which these conditions can be met. The Westinghouse coil for the Large Coil Task (LCT) is used as the basis for illustrative examples.

  2. GOZCARDS Source Data for Water Vapor Monthly Zonal Means on a Geodetic Latitude and Pressure Grid V1.01

    Data.gov (United States)

    National Aeronautics and Space Administration — The GOZCARDS Source Data for Water Vapor Monthly Zonal Averages on a Geodetic Latitude and Pressure Grid product (GozSmlpH2O) contains zonal means and related...

  3. GOZCARDS Merged Data for Water Vapor Monthly Zonal Means on a Geodetic Latitude and Pressure Grid V1.01

    Data.gov (United States)

    National Aeronautics and Space Administration — The GOZCARDS Merged Data for Water Vapor Monthly Zonal Averages on a Geodetic Latitude and Pressure Grid product (GozMmlpH2O) contains zonal means and related...

  4. Measurement of fluid flow by means of pressure differential devices inserted in circular cross-section conduits running full -- Part 4: Venturi tubes

    CERN Document Server

    International Organization for Standardization. Geneva

    2003-01-01

    ISO 5167-4:2003 specifies the geometry and method of use (installation and operating conditions) of Venturi tubes when they are inserted in a conduit running full to determine the flowrate of the fluid flowing in the conduit. ISO 5167-4:2003 also provides background information for calculating the flow-rate and is applicable in conjunction with the requirements given in ISO 5167-1. ISO 5167-4:2003 is applicable only to Venturi tubes in which the flow remains subsonic throughout the measuring section and where the fluid can be considered as single-phase. In addition, each of these devices can only be used within specified limits of pipe size, roughness, diameter ratio and Reynolds number. ISO 5167-4:2003 is not applicable to the measurement of pulsating flow. It does not cover the use of Venturi tubes in pipes sized less than 50 mm or more than 1 200 mm, or for where the pipe Reynolds numbers are below 20 000. ISO 5167-4:2003 deals with the three types of classical Venturi tubes: cast, machined and rough welde...

  5. Method and device for controlling tank vapors on a petroleum storage tank

    International Nuclear Information System (INIS)

    This patent describes a method for controlling tank vapors on a petroleum storage tank of the type having a tank vapor line running to a suction scrubber, the scrubber being connected by a conduit to a reciprocating compressor which, in turn, is connected to a compressed vapor discharge line for passing compressed vapors to a gas sales line. It comprises: operating the reciprocating compressor to draw tank vapor through the suction scrubber and through the reciprocating compressor to discharge vapor through the compressed vapor discharge line; installing pneumatic control means in the tank vapor line for controlling the flow of tank vapors to the suction scrubber; and providing the pneumatic control valve means with pilot means for controlling the operation of the control valve means

  6. Rosseland mean opacities of air and H-chondrite vapor in meteor entry problems

    International Nuclear Information System (INIS)

    The Rosseland mean absorption coefficients are determined for air and the vapor of the H-chondrites for use in calculating the ablation behavior of asteroidal meteoroids. For air, the calculated is made for temperatures between 8000 K and 35,000 K, and for H-chondrites from 3000 K to 20,000 K. Density values of 0.01, 0.1, 1., and 10 kg/m3 are considered. For H-chondrite, O, Si, Mg, Fe, S, O+, Si+, Mg+, S+, O2, SiO, MgO, FeO, and SO are considered as radiators. The latest available data on intensity parameters are used. To ensure accuracy, line profiles are calculated far into the wings. Bound-free absorption by the states of principal quantum numbers equal to or larger than four are accounted for assuming the associated Gaunt factors to be unity. The calculated Rosseland mean absorption coefficient values are substantially larger than the published values, especially at low temperatures. -- Highlights: •Rosseland mean absorption coefficients of air and H-chondrite are given. •Radiation mechanisms previously not considered are accounted for. •Temperature and pressure ranges are those expected in entry flights of meteors. •The calculated coefficient values are larger than the existing values

  7. Transverse colon conduit diversion

    International Nuclear Information System (INIS)

    The versatility and other advantages of the transverse colon conduit for urinary diversion have been described and implemented in 50 patients. Because most patients considered for this procedure will be at high risk because of a history of significant pelvic irradiation, underlying malignancy, poor renal function, fistula, and so forth, the technical details of surgery and patient selection cannot be minimized. The transverse colon segment is indicated for primary supravesical diversion as well as for salvage of problems related to ileal conduits. Adenocarcinoma of the colon is an unlikely long-term complication of this form of diversion because the fecal stream is absent. Now that the transverse colon conduit has been used for more than 10 years, meaningful comparisons with ileal segments should soon be available

  8. Apparatus for sealing the seam between two conduits

    International Nuclear Information System (INIS)

    An apparatus is described for sealing the seam between first and second axially aligned conduits comprising: sealing means disposed at the seam between the first and second conduits; a spacer having means for detachable connecting to the first conduit in such a manner as to apply a generally uniform axial force to the perimeter of the first conduit and a first threaded surface; a second spacer connecting to the second conduit; at least one of the spacer means being rotatably disposed with respect to the connected conduit; and the first threaded surface and a second threaded surface cooperating to relatively axially displace the first conduit and the second conduit by applying the axial forces thereto to compress the sealing means when the first spacer means and the second spacer means are relatively rotated. This patent also describes means for this apparatus to be used in a nuclear reactor pressure vessel in combination with an instrumentation port extending through the pressure vessel and comprising a male flange secured to the pressure vessel, an instrumentation port column extending through the male flange, and generally annular sealing means between the male flange and instrumentation port column which forms a seal therebetween when the port column is axially displaced relative to the male flange

  9. Seal between metal and ceramic conduits

    Science.gov (United States)

    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.

  10. Flexible cryogenic conduit

    International Nuclear Information System (INIS)

    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

  11. Arrangement of heat conduits

    International Nuclear Information System (INIS)

    Two conventional heat conducting systems are combined end to end in opposition, one end of the arrangement being exposed and sensitive to the temperature of one environment or object being monitored, whilst the heat furnished at the other end is intentionally controlled. The condensation sections adjacent to the respective heat conduits combine to form a common condensation area that is in turn coupled to an appropriate thermal dissipator. The temperature of the monitored end and that of the controlled end of the heat conducting arrangement each produce a vaporisation of the working fluid resulting in a flow of the respective vaporised fluids moving in opposite directions and which meet in the end to form an interaction interface in the common condensation area. The position of this interaction interface depends on the steam pressure in the respective heat conduits. These pressures depend in turn on the respective temperatures and thermal powers of the sources at the controlled and monitored ends of the heat conducting arrangement. This arrangement of heat conduits can be employed as a heat valve or heat bridge

  12. Fabrication of lightweight ceramic mirrors by means of a chemical vapor deposition process

    Science.gov (United States)

    Goela, Jitendra S. (Inventor); Taylor, Raymond L. (Inventor)

    1991-01-01

    A process to fabricate lightweigth ceramic mirrors, and in particular, silicon/silicon carbide mirrors, involves three chemical vapor deposition steps: one to produce the mirror faceplate, the second to form the lightweight backstructure which is deposited integral to the faceplate, and the third and final step which results in the deposition of a layer of optical grade material, for example, silicon, onto the front surface of the faceplate. The mirror figure and finish are fabricated into this latter material.

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

    Science.gov (United States)

    Metzger, Richard H. (West Seneca, NY)

    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.

  14. Conduit Coating Abrasion Testing

    Science.gov (United States)

    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.

  15. Conduit coupling assembly

    International Nuclear Information System (INIS)

    A conduit coupling assembly for coupling pipes with an interposed seal has a first part for receiving a pipe and is in splined engagement with a bush fixed to a pipe. A second part having radial fingers so that it can be turned by a manipulator, has a threaded engagement with the first part which is the same hand but different pitch to a threaded engagement between the second part and the bush. Pitches of 8:7 for couplings will give a mechanical advantage of 56:1 thus reducing the force needed to obtain a given axial movement of the bush and thus of the pipe and compression of the seal. (author)

  16. A foil shielded flexible conduit

    International Nuclear Information System (INIS)

    A foil shielded flexible conduit is described that is suitable for withstanding electromagnetic interference and electromagnetic pulses and may be employed in a nuclear reactor environment. Previous attempts to manufacture such conduits have all suffered from an insufficient degree of flexibility to allow suitable installation and have been liable to breakdown in service. (U.K.)

  17. Method and device for separating gaseous or vaporous materials, especially isotopes, by means of separation nozzles

    International Nuclear Information System (INIS)

    A method is provided for separating gaseous or vaporous substances, especially isotopes, with different molecular weights and/or different gas kinetic cross sections, in which the mixture of substances to be separated is passed through separation nozzles. One or more skimmer diaphragms project into the flow path of the substances and are used to separate and remove fractions of different compositions, and several separation systems consisting of nozzles and skimmer diaphragms are arranged in a cascade. The cascade generates partial streams which contain the mixture of substances to be separated. The partial streams can contain an additional gas with each partial stream containing different fractions of additional gas. When the partial streams generated within the cascade contain different fractions of additional gas, the partial streams are jointly fed to one of the separation nozzle systems in such a way as to generate a molar fraction gradient with respect to the additional gas which is opposed in direction to the molar fraction gradient being generated by the separation process within the nozzle. The partial streams can contain different compositions of the mixture of substances to be separated. When the partial streams generated within the cascade contain different compositions of the mixture of substances to be separated, the partial streams are jointly fed to one of the separation nozzle systems in such a way as to generate a molar fraction ratio with respect to the substances to be separated which is identical in direction with the molar fraction gradient being generated by the separation process within the nozzle. 27 claims, 13 figures

  18. 76 FR 76895 - Conduit Financing Arrangements

    Science.gov (United States)

    2011-12-09

    ...C) of the conduit financing regulations to treat an...determining whether a conduit financing arrangement exists. The...foreign law purposes and equity for U.S. purposes) should constitute per se ``financing transactions''...

  19. Limitations of Conduits in Peripheral Nerve Repairs

    OpenAIRE

    Moore, Amy M.; Kasukurthi, Rahul; Magill, Christina K.; Farhadi, H. Francis; Borschel, Gregory H; Mackinnon, Susan E.

    2009-01-01

    Nerve conduits have emerged as alternatives to autologous nerve grafts, but their use in large-diameter nerve deficits remains untested. We report four patients who underwent repair of large-diameter nerves using absorbable nerve conduits and discuss the failed clinical outcomes. The reported cases demonstrate the importance of evaluating the length, diameter, and function of nerves undergoing conduit repair. In large-diameter nerves, the use of conduits should be carefully considered.

  20. Empirical model for mean temperature for Indian zone and estimation of precipitable water vapor from ground based GPS measurements

    Directory of Open Access Journals (Sweden)

    C. Suresh Raju

    2007-10-01

    Full Text Available Estimation of precipitable water (PW in the atmosphere from ground-based Global Positioning System (GPS essentially involves modeling the zenith hydrostatic delay (ZHD in terms of surface Pressure (Ps and subtracting it from the corresponding values of zenith tropospheric delay (ZTD to estimate the zenith wet (non-hydrostatic delay (ZWD. This further involves establishing an appropriate model connecting PW and ZWD, which in its simplest case assumed to be similar to that of ZHD. But when the temperature variations are large, for the accurate estimate of PW the variation of the proportionality constant connecting PW and ZWD is to be accounted. For this a water vapor weighted mean temperature (Tm has been defined by many investigations, which has to be modeled on a regional basis. For estimating PW over the Indian region from GPS data, a region specific model for Tm in terms of surface temperature (Ts is developed using the radiosonde measurements from eight India Meteorological Department (IMD stations spread over the sub-continent within a latitude range of 8.5°–32.6° N. Following a similar procedure Tm-based models are also evolved for each of these stations and the features of these site-specific models are compared with those of the region-specific model. Applicability of the region-specific and site-specific Tm-based models in retrieving PW from GPS data recorded at the IGS sites Bangalore and Hyderabad, is tested by comparing the retrieved values of PW with those estimated from the altitude profile of water vapor measured using radiosonde. The values of ZWD estimated at 00:00 UTC and 12:00 UTC are used to test the validity of the models by estimating the PW using the models and comparing it with those obtained from radiosonde data. The region specific Tm-based model is found to be in par with if not better than a similar site-specific Tm-based model for the near equatorial station, Bangalore. A simple site-specific linear relation without accounting for the temperature effect through Tm is also found to be quite adequate for Bangalore. But for Hyderabad, a station located at slightly higher latitude, the deviation for the linear model is found to be larger than that of the Tm-based model. This indicates that even though a simple linear regression model is quite adequate for the near equatorial stations, where the temperature variations are relatively small, for estimating PW from GPS data at higher latitudes this model is inferior to the Tm-based model.

  1. Urinary conduits in gynecologic oncology

    International Nuclear Information System (INIS)

    Over an 11-year period (1971 to 1981), 212 urinary conduit surgeries were performed by the Department of Gynecology at the University of Texas, M. D. Anderson Hospital and Tumor Institute at Houston. The urinary diversions were performed as part of the pelvic exenteration operation in 154 patients, for radiation injury in 48 patients, and for palliation of disease recurrence in ten patients. Ninety-three percent had prior pelvic radiotherapy. Various segments of the gastrointestinal tract were used, including the ileum (102), sigmoid colon (99), transverse colon (four), jejunum (four), and others (three). Fifty percent of abnormal preoperative intravenous pyelograms reverted to normal after urinary diversion. Revision of the stoma was required in 6%. Other complications included infection (18%), renal loss (17%), and urinary leaks and fistulae (3%). The overall perioperative mortality was 7%, decreasing from 11% in the first five years to 3% during the last six years. Ureteral stents were routinely used. When selecting a segment of bowel for a urinary conduit, both tissue quality and mobility are important. Mortality and morbidity of urinary conduit surgery continues to decrease with experience

  2. Peripheral nerve conduits: technology update

    Directory of Open Access Journals (Sweden)

    Arslantunali D

    2014-12-01

    Full Text Available D Arslantunali,1–3,* T Dursun,1,2,* D Yucel,1,4,5 N Hasirci,1,2,6 V Hasirci,1,2,7 1BIOMATEN, Center of Excellence in Biomaterials and Tissue Engineering, Middle East Technical University (METU, Ankara, Turkey; 2Department of Biotechnology, METU, Ankara, Turkey; 3Department of Bioengineering, Gumushane University, Gumushane, Turkey; 4Faculty of Engineering, Department of Medical Engineering, Acibadem University, Istanbul, Turkey; 5School of Medicine, Department of Histology and Embryology, Acibadem University, Istanbul, Turkey; 6Department of Chemistry, Faculty of Arts and Sciences, METU, Ankara, Turkey; 7Department of Biological Sciences, Faculty of Arts and Sciences, METU, Ankara, Turkey *These authors have contributed equally to this work Abstract: 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. Keywords: peripheral nerve injury, natural biomaterials, synthetic biomaterials

  3. Imparting super hydro/oleophobic properties to cotton fabric by means of molecular and nanoparticles vapor deposition methods

    Energy Technology Data Exchange (ETDEWEB)

    Aminayi, Payam; Abidi, Noureddine, E-mail: n.abidi@ttu.edu

    2013-12-15

    Super hydro/oleophobic cotton fabrics were prepared using nanoparticle vapor deposition and molecular vapor deposition techniques. The surface was roughened by trimethylaluminum/water nanoparticles followed by functionalization with (tridecafluoro-1,1,2,2-tetrahydrooctyl)trichlorosilane. This process imparted unique hydro/oleophobic properties (contact angle >160°). In contrast to wet chemistry processes, the chemicals used and the thickness of the coatings produced by this method could be controlled precisely, which allowed for the minimization of waste generation while preserving the original properties of the fabric. Dynamic contact angles were measured and the fabrics that were coated using this technique showed low-contact-angle hysteresis properties. Scanning electron microscopy and universal attenuated total reflectance Fourier transform infrared spectroscopy confirmed the formation of a nanostructure-roughened surface. Drop dynamics such as the force of droplet movement, work of adhesion, and surface free energy were also calculated.

  4. Meaning

    Science.gov (United States)

    Harteveld, Casper

    The second world to be considered concerns Meaning. In contrast to Reality and Play, this world relates to the people, disciplines, and domains that are focused on creating a certain value. For example, if this value is about providing students knowledge about physics, it involves teachers, the learning sciences, and the domains education and physics. This level goes into the aspects and criteria that designers need to take into account from this perspective. The first aspect seems obvious when we talk of “games with a serious purpose.” They have a purpose and this needs to be elaborated on, for example in terms of what “learning objectives” it attempts to achieve. The subsequent aspect is not about what is being pursued but how. To attain a value, designers have to think about a strategy that they employ. In my case this concerned looking at the learning paradigms that have come into existence in the past century and see what they have to tell us about learning. This way, their principles can be translated into a game environment. This translation involves making the strategy concrete. Or, in other words, operationalizing the plan. This is the third aspect. In this level, I will further specifically explain how I derived requirements from each of the learning paradigms, like reflection and exploration, and how they can possibly be related to games. The fourth and final aspect is the context in which the game is going to be used. It matters who uses the game and when, where, and how the game is going to be used. When designers have looked at these aspects, they have developed a “value proposal” and the worth of it may be judged by criteria, like motivation, relevance, and transfer. But before I get to this, I first go into how we human beings are meaning creators and what role assumptions, knowledge, and ambiguity have in this. I will illustrate this with some silly jokes about doctors and Mickey Mouse, and with an illusion.

  5. 77 FR 22480 - Conduit Financing Arrangements; Correction

    Science.gov (United States)

    2012-04-16

    ..., 2011 (76 FR 76895) providing guidance on conduit financing arrangements. The final regulations apply to... Internal Revenue Service 26 CFR Part 1 RIN 1545-BH77 Conduit Financing Arrangements; Correction AGENCY: Internal Revenue Service (IRS), Treasury. ACTION: Correcting amendment. SUMMARY: This document contains...

  6. 76 FR 76895 - Conduit Financing Arrangements

    Science.gov (United States)

    2011-12-09

    ... Internal Revenue Service 26 CFR Part 1 RIN 1545-BH77 Conduit Financing Arrangements AGENCY: Internal... authority granted by section 7701(l) of the Internal Revenue Code (the conduit financing regulations). See TD 8611 (1995-37 IRB 20; 60 FR 40997). On December 22, 2008, the Treasury Department and the...

  7. Sealing of conduits penetrating fire barriers

    International Nuclear Information System (INIS)

    This paper discusses the results of a research fire test conducted to evaluate the internal sealing requirements for conduits penetrating fire barriers. The project was funded by a group of nuclear utilities in order to develop conduit sealing guidelines based on sound technical information in response to regulatory guidance. A test slab incorporating 101 conduit penetrations was exposed to the ASTM E-119 standard fire exposure for three hours. During the test, no flames propagated through the conduits and no cables were ignited on the unexposed side of the test slab. Guidelines were developed based on the test results which provide recommended sealing practices for conduits of diameters six inches or smaller which penetrate fire barriers. The test report has been submitted to the Nuclear Regulatory Commission (NRC) for review as a proprietary topical report. 4 refs., 3 figs

  8. Preparation of wide range refractive index diamond-like carbon films by means of plasma-enhanced chemical vapor deposition.

    Science.gov (United States)

    Gharibyan, A; Hayrapetyan, D; Panosyan, Zh; Yengibaryan, Ye

    2011-11-01

    Plasma-enhanced chemical vapor deposition technology has been elaborated for obtaining diamond-like carbon (DLC) coatings of a wide range of properties. Alternative and direct bias voltages have been applied on the substrate, and refractive index dependencies upon various deposition technological parameters have been investigated. The frequency of the bias voltage has been varied in the region of 150-450 kHz. The maximum refractive index range that has been achieved is 1.46-3.2. Thin DLC films have been prepared on crystalline silicon substrates. Because of the wide range of physical, optical, and mechanical properties of the obtained films, they can successfully be applied in different fields of nano-optics. PMID:22086050

  9. Numerical and experimental investigation of DNAPL removal mechanisms in a layered porous medium by means of soil vapor extraction

    Science.gov (United States)

    Yoon, Hongkyu; Oostrom, Mart; Wietsma, Thomas W.; Werth, Charles J.; Valocchi, Albert J.

    2009-10-01

    The purpose of this work is to identify the mechanisms that govern the removal of carbon tetrachloride (CT) during soil vapor extraction (SVE) by comparing numerical and analytical model simulations with a detailed data set from a well-defined intermediate-scale flow cell experiment. The flow cell was packed with a fine-grained sand layer embedded in a coarse-grained sand matrix. A total of 499 mL CT was injected at the top of the flow cell and allowed to redistribute in the variably saturated system. A dual-energy gamma radiation system was used to determine the initial NAPL saturation profile in the fine-grained sand layer. Gas concentrations at the outlet of the flow cell and 15 sampling ports inside the flow cell were measured during subsequent CT removal using SVE. Results show that CT mass was removed quickly in coarse-grained sand, followed by a slow removal from the fine-grained sand layer. Consequently, effluent gas concentrations decreased quickly at first, and then started to decrease gradually, resulting in long-term tailing. The long-term tailing was mainly due to diffusion from the fine-grained sand layer to the coarse-grained sand zone. An analytical solution for a one-dimensional advection and a first-order mass transfer model matched the tailing well with two fitting parameters. Given detailed knowledge of the permeability field and initial CT distribution, we were also able to predict the effluent concentration tailing and gas concentration profiles at sampling ports using a numerical simulator assuming equilibrium CT evaporation. The numerical model predictions were accurate within the uncertainty of independently measured or literature derived parameters. This study demonstrates that proper numerical modeling of CT removal through SVE can be achieved using equilibrium evaporation of NAPL if detailed fine-scale knowledge of the CT distribution and physical heterogeneity is incorporated into the model. However, CT removal could also be fit by a first-order mass transfer analytical model, potentially leading to an erroneous conclusion that the long-term tailing in the experiment was kinetically controlled due to rate-limited NAPL evaporation.

  10. Pumped Storage and Potential Hydropower from Conduits

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Control adaptativo para arranque de generadores de vapor mediante redes neuronales dinámicas / STEAM GENERATORS START-UP BY MEANS OF AN ADAPTIVE CONTROL AND DYNAMIC NEURAL NETWORKS

    Scientific Electronic Library Online (English)

    Miguel, Aguirre.

    2009-06-01

    Full Text Available En este documento se describe el modelado y el control adaptativo mediante redes neuronales auto-recurrentes para arranque de un generador de vapor, con el fin de disminuir el tiempo de arranque y minimizar las variaciones y fallas por ajuste manual de las variables involucradas en este proceso. La [...] variable de proceso a controlar para el arranque, es principalmente la temperatura, además se controla el oxigeno para garantizar la máxima eficiencia de la combustión en los quemadores. Ambas se controlan mediante la manipulación de la relación gas natural/aire de combustión. Los datos de entrenamiento son empíricos del proceso y son medidos cada 2 minutos. La simulación del proceso y del controlador se realizó en MATLAB. Las acciones de control resultantes concuerdan con un arranque normal del generador de vapor. Abstract in english In this document it will be explain the modeling and adaptive control by means of auto-recurrent neural networks for steam generators start-up with the purpose of obtain a minimum in the start-up time, the variance and the failures for manual settings of the process variables. The primary start-up p [...] rocess variable to control is the temperature, but in addition will be control the oxygen for guarantee the maximum performance of the burner combustion. Both variables were controlled setting the relation between the natural gas and combustion air. The training data are empiric of the process and it was sampled every 2 minutes. The process and controller simulation was realized in MATLAB. The controller actions obtained in the simulations had concordance with a normal start up of the steam generator.

  12. Variability of permeability with diameter of conduit

    Indian Academy of Sciences (India)

    J A Adegoke; J A Olowofela

    2008-05-01

    An entry length is always observed before laminar flow is achieved in fluid flowing in a conduit. This depends on the Reynolds number of the flow and the degree of smoothness of the conduit. This work examined this region and the point where laminar flow commences in the context of flow through conduit packed with porous material like beads, of known porosity. Using some theoretical assumptions, it is demonstrated that permeability varies from zero at wall-fluid boundary to maximum at mid-stream, creating a permeability profile similar to the velocity profile. An equation was obtained to establish this. We also found that peak values of permeability increase with increasing porosity, and therefore entry length increases with increasing porosity with all other parameters kept constant. A plot of peak permeability versus porosity revealed that they are linearly related.

  13. Prediction of supercooled liquid vapor pressures and n-octanol/air partition coefficients for polybrominated diphenyl ethers by means of molecular descriptors from DFT method

    International Nuclear Information System (INIS)

    The molecular geometries of 209 polybrominated diphenyl ethers (PBDEs) were optimized at the B3LYP/6-31G* level with Gaussian 98 program. The calculated structural parameters were taken as theoretical descriptors to establish two novel QSPR models for predicting supercooled liquid vapor pressures (PL) and octanol/air partition coefficients (KOA) of PBDEs based on the theoretical linear solvation energy relationship (TLSER) model, respectively. The two models achieved in this work both contain three variables: most negative atomic partial charge in molecule (q-), dipole moment of the molecules (?) and mean molecular polarizability (?), of which R2 values are both as high as 0.997, their root-mean-square errors in modeling (RSMEE) are 0.069 and 0.062 respectively. In addition, the F-value of two models are both evidently larger than critical values F0.05 and the variation inflation factors (VIF) of variables herein are all less than 5.0, suggesting obvious statistic significance of the PL and KOA predicting models. The results of Leave-One-Out (LOO) cross-validation for training set and validation with external test set both show that the two models obtained exhibited optimum stability and good predictive power. We suggest that the QSPRs derived here can be used to predict accurately PL and KOA for non-tested PBDE congeners from Mono-BDEs to Hepta-BDEs and from Mono-BDEs to Hexa-BDEs, respectively

  14. MR and CT imaging of pulmonary valved conduits in children and adolescents: normal appearance and complications

    Energy Technology Data Exchange (ETDEWEB)

    Tenisch, Estelle V.; Alamo, Leonor T.; Gudinchet, Francois [Lausanne University Hospital, Department of Medical Imaging, Lausanne (Switzerland); Sekarski, Nicole [Lausanne University Hospital, Department of Pediatrics, Lausanne (Switzerland); Hurni, Michel [Lausanne University Hospital, Department of Cardiovascular Surgery, Lausanne (Switzerland)

    2014-12-15

    The Contegra registered is a conduit made from the bovine jugular vein and then interposed between the right ventricle and the pulmonary artery. It is used for cardiac malformations in the reconstruction of right ventricular outflow tract. To describe both normal and pathological appearances of the Contegra registered in radiological imaging, to describe imaging of complications and to define the role of CT and MRI in postoperative follow-up. Forty-three examinations of 24 patients (17 boys and 7 girls; mean age: 10.8 years old) with Contegra registered conduits were reviewed. Anatomical description and measurements of the conduits were performed. Pathological items examined included stenosis, dilatation, plicature or twist, thrombus or vegetations, calcifications and valvular regurgitation. Findings were correlated to the echographic gradient through the conduit when available. CT and MR work-up showed Contegra registered stenosis (n = 12), dilatation (n = 9) and plicature or twist (n = 7). CT displayed thrombus or vegetations in the Contegra registered in three clinically infected patients. Calcifications of the conduit were present at CT in 12 patients and valvular regurgitation in three patients. The comparison between CT and/or MR results showed a good correlation between the echographic gradient and the presence of stenosis in the Contegra registered. CT and MR bring additional information about permeability and postoperative anatomy especially when echocardiography is inconclusive. Both techniques depict the normal appearance of the conduit, and allow comparison and precise evaluation of changes in the postoperative follow-up. (orig.)

  15. MR and CT imaging of pulmonary valved conduits in children and adolescents: normal appearance and complications

    International Nuclear Information System (INIS)

    The Contegra registered is a conduit made from the bovine jugular vein and then interposed between the right ventricle and the pulmonary artery. It is used for cardiac malformations in the reconstruction of right ventricular outflow tract. To describe both normal and pathological appearances of the Contegra registered in radiological imaging, to describe imaging of complications and to define the role of CT and MRI in postoperative follow-up. Forty-three examinations of 24 patients (17 boys and 7 girls; mean age: 10.8 years old) with Contegra registered conduits were reviewed. Anatomical description and measurements of the conduits were performed. Pathological items examined included stenosis, dilatation, plicature or twist, thrombus or vegetations, calcifications and valvular regurgitation. Findings were correlated to the echographic gradient through the conduit when available. CT and MR work-up showed Contegra registered stenosis (n = 12), dilatation (n = 9) and plicature or twist (n = 7). CT displayed thrombus or vegetations in the Contegra registered in three clinically infected patients. Calcifications of the conduit were present at CT in 12 patients and valvular regurgitation in three patients. The comparison between CT and/or MR results showed a good correlation between the echographic gradient and the presence of stenosis in the Contegra registered. CT and MR bring additional information about permeability and postoperative anatomy especially when echocardiography is inconclusive. Both techniques depict the normal appearance of the conduit, and allow comparison and precise evaluation of changes in the postoperative follow-up. (orig.)

  16. Long-term follow-up of patients with extracardiac valved conduits.

    Directory of Open Access Journals (Sweden)

    Sano,Shunji

    1989-06-01

    Full Text Available Seventeen patients having extracardiac valved conduits placed between the right ventricle and pulmonary artery were followed for 7 to 87 months postoperatively (mean, 42 months, at the Heart Institute, Kenritsu Amagasaki Hospital, Japan. There were no late deaths in the study group. Three conduits have been replaced, all because of conduit stenosis. In two-dimensional echocardiographic examinations, commissural fusion and calcification of the valve were noted in 6 out of 16 xenograft valved conduits. Mechanical valve immobility was found in one patient. Neointimal peel of the dacron graft was noted in 6 out of 17 cases, and marked left ventricular deformity in the short axis view was found in 6. Late cardiac catheterization was done in 6 patients who were suspected of having valve failure and right ventricular hypertension by two-dimensional echocardiography. All 6 of these patients showed a high pressure gradient between the pulmonary artery and right ventricle and also had elevated right ventricular pressure. In conclusion, two-dimensional echocardiography is a simple, non-invasive and very accurate method for detecting conduit stenosis and valve failure. An echocardiographic series should be performed for a long-time postoperatively because obstructions of valved conduits may be progressive, and an operation may be advisable in order to prevent the development of advanced right ventricular hypertrophy and deterioration.

  17. Karst conduit sinuosity as a driver of karst hyporheic exchange

    Science.gov (United States)

    Wilson, J. L.; Henry, K.

    2013-12-01

    It has recently been suggested by the authors that water from a flowing phreatic karst conduit can enter the surrounding permeable matrix, in an analogy to hyporheic exchange for streams. Within the matrix two consequences of this exchange are processing of conduit water chemistry and speleogenesis. Small-scale exchange to and from the conduit is promoted by hydraulic head variations created by the conduit wall topology, but there is also a larger scale exchange created by conduit sinuosity and axial conduit head gradients. Considering several types of sinuosity, we use mathematical modeling of conduit flow to drive 3D matrix flow and exchange, examining the patterns, rates, and residence times of exchange and the resulting implications for water chemistry and additional speleogenesis. Presenting results in terms of dimensionless numbers allows us to address karst conduits at different stages of development, and to assess the importance of sinuosity driven exchange in terms of diver-observable features in the larger conduits.

  18. A case report of complication liked jejunal conduit syndrome induced by reconstruction of ileal conduit

    International Nuclear Information System (INIS)

    The patient was a 77-year-old man who underwent radical cystectomy and ileal conduit urinary diversion due to bladder cancer in 1989. A stenosis of the right uretero-ileal anastomosis occurred in 1992, and of the left uretero-ileal anastomosis in 1999. These were treated with indwelling of a ureteral stent and percutaneous nephrostomy, respectively. He was admitted to our hospital for progressive renal dysfunction due to frequent pyelonephritis. We performed a reconstruction of the ileal conduit urinary diversion and after the removal of the bilateral ureteral stent he complained of nausea and general malaise. The laboratory data showed hyponatremia, hyperkalemia and azotemia, which were diagnosed as complication liked jejunal conduit syndrome. He was treated with hydration and salt supplementation. With regard to this case, we considered that a long ileal conduit close to the jejunum and renal dysfunction caused the complication liked jejunal conduit syndrome. Careful observation and follow-up laboratory examination should be performed if the patient has renal dysfunction and a long conduit near the jejunum is used for the ileal conduit. (author)

  19. Norwood-sano operation using a stentless pulmonary valved conduit.

    Science.gov (United States)

    Ginestar, Andrés Castelló; Martinez, F Serrano; Argudo, J A Montero; Calvar, J M Caffarena

    2011-01-01

    The Sano modification of Norwood's operation has the potential to generate an excess volume load on the single right ventricle as a consequence of diastolic reversal of flow through the conduit. This article describes the use of a new, small, biological conduit with a porcine valve inside. This new conduit has been used in modified Norwood procedures. It is interposed between the right ventricle and the confluence of the pulmonary arteries. The use of a valved conduit should prevent the retrograde diastolic blood flow observed with use of nonvalved conduits and may improve postoperative hemodynamics. The use of a new stentless valved conduit in 3 recent Norwood procedures is reported herein. PMID:23804945

  20. MRI of the heart following implantation of a left ventricular apico-aortic conduit

    International Nuclear Information System (INIS)

    Purpose: To investigate the potential of ECG-triggered MRI for the evaluation of postoperative anatomy and function of the heart and conduit following implantation of a left-ventricular apico-aortic conduit. Materials and Methods: 5 patients (2 female, 3 male, mean age 72.5 years) were examined using a 1.5 Tesla whole-body MRI (Gyroscan Intera, Philips Medical Systems, Best, The Netherlands) following apico-aortic conduit surgery due to severe aortic valve stenosis. The reason for performing conduit implantation instead of aortic valve replacement was the risk of injuring a bypass graft from prior coronary artery bypass surgery. Cine steady-state-free-precession (SSFP) sequences were used to assess ventricular function, navigator-gated 3D-SSFP and breath-hold, time-resolved contrast-enhanced MR angiography was used to display the postoperative anatomy, and 2D-gradient echo sequences with an inversion pulse to suppress the signal of the healthy myocardium were used to evaluate potential myocardial scarring. Flow sensitive gradient echo sequences were performed to determine the blood flow in the conduit. Results: In all patients the apico-aortic conduit proved to be open with a maximum flow velocity of 126 (+ 43) cm/s. The postoperative anatomy was able to be evaluated in all patients and perioperative myocardial infarction was able to be ruled out. The mean ejection fraction of the left ventricle was 44.2 + 6.2 % with a mean volume of 80 + 20.6 ml per heart beat. (orig.)

  1. Biochemical engineering nerve conduits using peptide amphiphiles.

    OpenAIRE

    A Tan; Rajadas, J.; Seifalian, A M

    2012-01-01

    Peripheral nerve injury is a debilitating condition. The gold standard for treatment is surgery, requiring an autologous nerve graft. Grafts are harvested from another part of the body (a secondary site) to treat the affected primary area. However, autologous nerve graft harvesting is not without risks, with associated problems including injury to the secondary site. Research into biomaterials has engendered the use of bioartificial nerve conduits as an alternative to autologous nerve grafts....

  2. Thermal damping and retardation in karst conduits

    Directory of Open Access Journals (Sweden)

    A. J. Luhmann

    2014-08-01

    Full Text Available Water temperature is a non-conservative tracer in the environment. Variations in recharge temperature are damped and retarded as water moves through an aquifer due to heat exchange between water and rock. However, within karst aquifers, seasonal and short-term fluctuations in recharge temperature are often transmitted over long distances before they are fully damped. Using analytical solutions and numerical simulations, we develop relationships that describe the effect of flow path properties, flow-through time, recharge characteristics, and water and rock physical properties on the damping and retardation of thermal peaks/troughs in karst conduits. Using these relationships, one can estimate the thermal retardation and damping that would occur under given conditions with a given conduit geometry. Ultimately, these relationships can be used with thermal damping and retardation field data to estimate parameters such as conduit diameter. We also examine sets of numerical experiments where we relax some of the assumptions used to develop these relationships, testing the effects of variable diameter, variable velocity, open channels, and recharge shape on thermal damping and retardation to provide some constraints on uncertainty. Finally, we discuss a tracer experiment that provides field confirmation of our relationships. High temporal resolution water temperature data are required to obtain sufficient constraints on the magnitude and timing of thermal peaks and troughs in order to take full advantage of water temperature as a tracer.

  3. Two-dimensional simulations of magma ascent in volcanic conduits

    Science.gov (United States)

    Ramos, J. I.

    1999-04-01

    A two-dimensional model for magma ascent in volcanic conduits is presented. The model accounts for the magma rheology, heat flux to the surrounding country rock, planar and axisymmetric geometries, and flow in the mushy region by means of a continuum mixture formulation that does not require keeping track of the liquid-solid interfaces. Numerical experiments for Newtonian and visco-plastic Bingham rheologies of magmas are presented as functions of the volumetric flow rate at the dyke's entrance and wall heat fluxes for both round conduits and fissures. It is shown that, depending on the magma rheology, dyke geometry, volumetric flow rate and wall heat flux, the magma may solidify along the original dyke's walls, thus reducing the available cross-sectional area to the flow, or the original dyke's walls may melt. It is also shown that the dyke's wall temperature may first increase and then decrease, and that the axial velocity profile exhibits a parabolic shape in the core region and a plug zone near the dyke's walls for Bingham rheologies. Copyright

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

    Energy Technology Data Exchange (ETDEWEB)

    Ziada, S.; Oengoeren, A. [Sulzer Innotec Limited, Winterthur (Switzerland); Vogel, H.H. [Swiss Locomotive and Machine Works, Winterthur (Switzerland)

    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.

  5. Liquid-Vapor Argon Isotope Fractionation from the Triple Point to the Critical Point : Mean Laplacian of the Intermolecular Potential in Liquid Argon

    DEFF Research Database (Denmark)

    Phillips, J. T.; LinderstrØm-Lang, C. U.

    1972-01-01

    The statistical thermodynamic treatment of the equilibrium between a nonideal liquid mixture of isotopes and a vapor phase is extended to include isotope effects on the equation of state of the gas. The result is particularly simple when the isotopic partition functions in a given phase are compared at the same molar volume. The isotope fractionation factor ? for 36Ar?40Ar between liquid and vapor has been measured from the triple point to the critical temperature. The results are compared with previous vapor pressure data, which cover the range 84–102°K. Although the agreement is within twice the statistical scatter of the present data, the present results for the ln? are systematically 5% lower than calculations from vapor pressure data. It is shown that T2 ln? is a linear function of (?c??g), the density difference between the liquid and vapor, in the range 84–120°K. The fractionation factor approaches zero at the critical temperature with a nonclassical critical index equal to 0.42±0.02.??2Uc?/?c in liquid argon is derived from the experimental fractionation data and calculations of ??2Ug?/?g for a number of potential functions for gaseous argon.

  6. Evolution of Hydraulic Roughness During Early Stages of Conduit Growth: Effects on Conduit Enlargement Rates

    Science.gov (United States)

    Gulley, J. D.; Spellman, P.; Covington, M. D.; Martin, J. B.; Benn, D.; Catania, G. A.

    2012-12-01

    Hydraulic roughness exerts an important but poorly constrained control on the hydraulic capacity and enlargement rates of subglacial conduits. In an ideal, inviscid fluid, energy and mass are conserved along a flow line and the sum of the velocity, pressure and elevation heads equals the potential energy of the system, as described by the Bernoulli Equation. In real fluid flows, however, some of this energy is dissipated as heat due to friction and turbulence, resulting in a total head that is lower than predicted by the Bernoulli Equation. This departure from ideal is termed head loss, which is accounted for in simple hydrological models, such as the Manning or Darcy Weisbach equations, through the use of a roughness coefficient (n -s m1/3) or a friction factor (f - dimensionless), respectively. Both f and n relate hydraulic roughness to a relative roughness, or the ratio of the height that projections extend from the floor or wall of a conduit to the conduit hydraulic diameter. Such relationships, however, are empirically derived and only valid for relative roughness values that are 5% likely occur in subglacial conduits, particularly during early stages of conduit enlargement, which may limit ability to use relative roughness to calculate values of n or f. Understanding changes in roughness in the early stages of conduit enlargement is crucial for accurate modeling of glacier hydrological systems because nearly all glacier hydrological models rely on a hydraulic roughness parameterization to drive conduit melting. To address this knowledge gap, we calculated hydraulic roughness values from dye traces conducted at Rieperbreen, in Svalbard, Norway. Because conduit area and hydraulic gradients were constrained by direct mapping, and average flow velocities were obtained from dye traces, we were able to calculate f and n for each trace. Values of f and n declined from 75.01 and 0.68 s m1/3, respectively, to 0.97 and 0.04 s m1/3 over the melt season. Values of f and n calculated from dye tracing data exceeded values of f and n calculated solely from direct measurements of relative roughness by several orders of magnitude. Despite these discrepancies, values of f and n that were calculated from dye tracing data were highly correlated to measured relative roughness values using a power law, suggesting that new relationships may be developed for glacier hydrological systems. When we paramaterized a simple conduit enlargement model using our newly-discovered relationship between f, n and relative roughness, we found that the timescale required for conduits to grow from 0.5 m in diameter to a diameter where relative roughness was <5% was 4-9 times longer than enlargement times obtained using roughness parameterization schemes commonly used in glacier hydrological models.

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

    Science.gov (United States)

    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

  8. The effect of Ti conduit on the critical current in (Nb,Ti)3Sn cable-in-conduit conductors

    International Nuclear Information System (INIS)

    The effect of titanium conduit on the critical current in (Nb,Ti)3Sn cable-in-conduit conductors was investigated to obtain a high performance conductor which would be applied to large superconducting magnets such as those for fusion machines. Titanium has equivalent thermal contraction coefficient to that of (Nb,Ti)3Sn filaments, and it is expected by using titanium as the conduit to suppress degradation of critical current due to excess thermal prestrain on (Nb,Ti)3Sn filaments. Some titanium conduit sample conductors were made, and thier critical current performance were measured together with some stainless steel (SUS316) and copper-nickel alloy (Cu-10Ni) conduit conductors. The experimental results indicated that the titanium conduit conductors had no critical current degradation due to thermal strain, whereas the stainless steel and copper-nickel alloy conduit conductors showed remarkable degradation on thier critical current performance and greater degradation was observed with smaller void conductor. In conclusion, titanium is verified to be excellent conduit material for (Nb,Ti)3Sn cable-in-conduit conductors. (author)

  9. Spotlight on CERN : Le code de conduite

    CERN Multimedia

    CERN Video Productions

    2010-01-01

    Cette année 2010, le démarrage du LHC a été le témoignage de la réussite de la collaboration scientifique au CERN, rapprochant les personnes, hommes et femmes, tous ensemble pour la plus grande des réalisations. Cette collaboration nécessite une ouverture sur la diversité basée sur des valeurs solides. Pour s’assurer que l'Organisation continue sur la voie du succès, un consensus a été atteint sur des valeurs caractérisant le CERN et celles-ci ont été regroupées dans un Code de conduite, décrivant la norme de base du comportement que nous pouvons tous espérer de nous-mêmes et de nos collègues sur notre lieu de travail. Entrevues avec Rolf Heuer, Directeur Général du CERN, Anne-Sylvie Catherin, Chef du Département des Ressources Humaines, et Vincent Vuillemin, Ombuds au CERN.

  10. Stability of quasi-steady flow in an englacial conduit

    Science.gov (United States)

    Szilder, Krzysztof; Lozowski, Edward P.

    1997-10-01

    The stability of water flow in an englacial conduit is examined with particular reference to catastrophic outbursts of water. Quasi-steady flow of water in a conduit is considered, the conduit being simultaneously enlarged by frictional heating and compressed by plastic deformation in response to the pressure difference across the tunnel wall. The conduit is fed by an ice-dammed reservoir. With the aid of simplifying assumptions, we have devised a mathematical model consisting of two time-dependent, non-linear, dimensionless ordinary differential equations, which describe the time evolution of the conduit cross-section and the water depth in the reservoir. The conditions leading to different types of time-dependent flow behaviour are examined. Regions of the parameter space where the water flow is stable and unstable have been identified. In the unstable regime, the process of emptying the reservoir has either an oscillatory or an exponential character. In the stable regime, the system's return to equilibrium, following a perturbation, also exhibits an oscillatory or exponential character. Examples of this time-dependent behaviour are presented. The model has also been used to study the influence of the glacier, conduit and reservoir geometries on the system's stability. The results show that an increase in the horizontal area of the water reservoir or an increase in the slope of the conduit enhance the likelihood of a sudden outburst. However, an increase in the glacier thickness or the conduit length stabilizes the equilibria.

  11. 26 CFR 1.7701(l)-1 - Conduit financing arrangements.

    Science.gov (United States)

    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...

  12. Investigation of SH and CS radicals formation dynamics inside the hot filament chemical vapor deposition environment by means of cavity ringdown spectroscopy

    Science.gov (United States)

    Buzaianu, Madalina Dora

    2008-10-01

    The addition of traces amounts of sulfur containing gasses, such as H 2S, during the hot filament chemical vapor deposition of diamond thin films involving methane and hydrogen as a carrier gas, proved to enhance the formation of the nano-structured diamond and cause significant changes in the film growth behavior. The sulfur-incorporated nanocrystalline diamond, showing interesting electronic and tribological properties, raised scientific inquires about the fundamental mechanisms occurring inside the HFCVD reactor during the diamond growth. A better insight into the gas-phase and heterogeneous underlying processes can generate new ides for the customizing and optimization of the diamond synthesis in the view of new prospects of valuable technological applications. The SH and CS radicals, thought to be among the important precursors in the gas-phase and heterogeneous chemistry, were studied by means of Cavity Ringdown Spectroscopy (CRDS), a powerful non-intrusive, self-calibrating spectroscopic diagnostic tool, employed to detect the A(0) ? X(0) transition near 323 and 259 nm for SH and CS, respectively, and the A(0) ? X(1) transition near 352 nm for the SH radical. CRDS is particularly suitable to detect SH and CS radicals due to its high sensitivity, discrimination and spatial resolution, as well as the ability to provide absolute values of species concentrations. The fitting of the measured CRD decay traces of the SH and CS radicals provided the corresponding ringdown times. The substantial changes in the ringdown times observed when the filament temperature was raised to 2700 +/- 50 K (from 4.04 +/- 0.04 to 0.260 +/- 0.003 mus for SH and from 4.12 +/- 0.05 to 3.04 +/- 0.03 mus for CS, respectively) are compatible with the presence of SH and CS radicals. A simulation of the rotationally resolved SH and CS spectra near UV, based on the analysis of the radicals' Doppler line width, led to an estimate of their effective rotational temperature. The values obtained are ˜ 1750 +/- 250 K and 1800 +/- 250 K for SH and CS, respectively, which are lower than the measured filament temperature (i.e. 2700 +/- 50 K) by 1000 K at 2 mm from the filament. The radicals' rotational temperatures were studied as a function of filament distance and found to linearly decrease as the distance from the filament increases, such that a drop of approximately 1200 K is observed between 2 mm and 10 mm distance from the filament. The estimated rotational, translational and vibrational (A(0) ? X(1) of the SH radical) temperatures were found in good agreement for both radicals. A convolution procedure of the SH S R1 (10.5) line and CS R(15) - R(22) line cluster, involving an analysis of the Doppler and Lorentzian broadening widths provided the absolute numerical value of the species concentration. The concentration of the SH radical (2.2 x 1012 cm-3 ) was found to be about two orders of magnitude below that of the initial H2S (2.8 x 1014 cm-3), but about two orders of magnitude higher than that of the CS radical (2.7 x 1010 cm-3), at 2 mm below the filament. The SH and CS radical concentration profiles in the HFCVD system were measured in the presence and absence of a substrate as a function of distance from the filament to the laser probing area. The SH concentration profile was found to decrease by two orders of magnitude as the distance from the filament to the laser probing area increases, while the CS concentration remains approximately constant. The radical concentration profiles were measured in the presence and absence of a substrate as a function and CH4 and H2S input gas concentration. The concentration of SH and CS radicals in the presence of substrate was found to increase linearly with the H2S concentration, decreasing as the CH4 concentration increases. In the absence of substrate, the concentration of the radicals was found to be higher for higher values of the H2S concentration and increase as the CH4 concentration increased. These finding suggest that the heterogeneous processes introduced by the presence of the substrate are

  13. Corrosion detection and monitoring in steam generators by means of ultrasound; Deteccion y monitoreo de corrosion por medio de ultrasonido en generadores de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Chacon Nava, Jose G.; Calva, Mauricio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico); Fuentes Samaniego, Raul [Universidad Autonoma de Nuevo Leon (Mexico); Peraza Garcia, Alejandro [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1987-12-31

    The tube and component failures in steam generators due to corrosion cause huge economical losses. In this article the internal corrosion processes (hydrogen attack) and high temperature corrosion are described, as well as the ultrasound techniques used for its detection. The importance of obtaining corrosion rates, which are fundamental parameters for the detection of the tube`s residual life. The purpose is to prevent possible failures that would diminish the power plant availability. [Espanol] Las fallas de tuberia en componentes de generadores de vapor debidas a corrosion ocasionan considerables perdidas economicas. En este articulo se describen los procesos de corrosion interna (ataque por hidrogeno) y corrosion en alta temperatura, asi como tecnicas de ultrasonido empleadas para su deteccion. Se destaca la importancia de obtener valores de velocidad de corrosion, que es un parametro fundamental para la determinacion de la vida residual de tuberias. El proposito es poder prevenir posibles fallas que disminuyan la disponibilidad de centrales termoelectricas.

  14. Biological conduit small gap sleeve bridging method for peripheral nerve injury: regeneration law of nerve fibers in the conduit

    Directory of Open Access Journals (Sweden)

    Pei-xun Zhang

    2015-01-01

    Full Text Available The clinical effects of 2-mm small gap sleeve bridging of the biological conduit to repair peripheral nerve injury are better than in the traditional epineurium suture, so it is possible to replace the epineurium suture in the treatment of peripheral nerve injury. This study sought to identify the regeneration law of nerve fibers in the biological conduit. A nerve regeneration chamber was constructed in models of sciatic nerve injury using 2-mm small gap sleeve bridging of a biodegradable biological conduit. The results showed that the biological conduit had good histocompatibility. Tissue and cell apoptosis in the conduit apparently lessened, and regenerating nerve fibers were common. The degeneration regeneration law of Schwann cells and axons in the conduit was quite different from that in traditional epineurium suture. During the prime period for nerve fiber regeneration (2-8 weeks, the number of Schwann cells and nerve fibers was higher in both proximal and distal ends, and the effects of the small gap sleeve bridging method were better than those of the traditional epineurium suture. The above results provide an objective and reliable theoretical basis for the clinical application of the biological conduit small gap sleeve bridging method to repair peripheral nerve injury.

  15. TiN film deposition on stainless steel by means of nitrogen ion beam and ionized Ti vapor and evaluation of its properties

    International Nuclear Information System (INIS)

    430-type stainless steel plates were coated with TiN films by four methods, ion beam assisted deposition (IBAD), ionization deposition (ID), ion beam assisted ionization deposition (IBAID) and ion plating (IP), and their color coordinates, microhardness, adhesion and deposition layer structure were compared. In IBAD, golden-colored TiN film was obtained at the substrate temperature higher than 700degC, at the nitrogen ion beam energy of about 200 eV and at the deposition rate lower than 0.19 nm/sec, while it was obtained at 400degC and at high deposition rate in ID, IBAID and IP. The TiN films deposited by the above mentioned four methods had almost the same microhardness (about 2250 kgf/mm2) and void-free dense structure. The adhesion of the TiN film deposited by IBAD was higher than those by the other three methods. This was considered to be due to the high mixing effect on the interface which was arose both from the high substrate temperature and from the high current density of nitrogen ion beam compared to the amount of Ti vapor flux. (author)

  16. Articulated device for guiding a band of conduits

    International Nuclear Information System (INIS)

    The device consists of a support comprising at least two articulated arms to form of a pair of compasses; when the compasses are closed, all the conduits have the same internal radius of curvature. Each arm comprises two bars connected by a holding structure between which the conduits are disposed. A bar of one arm is connected to a bar of the other arm by an articulated joint so that the two joints between the bars are on either side of the band of conduits during actuation of the arms. The device is useful for guiding electrical cables, fluid supply tubes, etc, in the core cover of a liquid metal cooled, fast neutron nuclear reactor. The device can maintain a large number of conduits without risk of tangling or rupture when the arms are closed

  17. Conduit Magma Storage during the 800 BP Quilotoa Eruption, Ecuador

    Science.gov (United States)

    Ort, M. H.; Cashman, K. V.; Di Muro, A.; Best, J. A.; Rosi, M.; Mothes, P. A.; Bustillos, J.

    2013-12-01

    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 conduit 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 a ~130 MPa isobar, suggesting shallow magma storage during the hiatus. Using these data, we hypothesize that the eruption of U1 ended when conduit constriction above 4 km choked the ascent of magma. Continued open-system degassing of the magma column produced the U2 MI compositions and led to milling and acid etching of the crystal-rich material, eliminating much of the glass. Periodic explosions during dome formation produced U2a. Continued magma ascent caused increased gas emissions that ejected U2b as a continuous column. As the U3 magma reached the surface, it blew out the dome prior to eruption of new deeper magma. The high pressures in MIs in plagioclase crystals in U1 and lack of any evidence for mafic magma supply imply the shallow dacitic system is fed by evolved magmas that differentiated at high pressure.

  18. Ileal-conduit following cystectomy, single-institution revision of indications and outcome

    International Nuclear Information System (INIS)

    Objective was to revise indications, case fatality ratio, and postoperative early and late complications of ileal conduit as a method of urinary diversion. This is a retrospective study in which 200 patients underwent an ileal conduit from August 1994 to December 2000 in Mansoura Urology and Nephrology Center, Mansoura, Egypt. Preoperative criteria of patient selection, preoperative findings and postoperative follow-up data were reviewed. In 200 patients aged 29-75 years, with a mean age of 55.84-/+ 8.91 years, the ileal conduit was chosen as a method of urinary diversion, due to one of the following patient or surgical factors; 50 (25%) cardiopulmonary co-morbidities, 27(13.5%) liver cirrhosis, 20 (10%) impaired renal function, 18 (9%) poorly controlled diabetes mellitus and 3 (1.5%) morbid obesity. Frozen section pathological examination showed carcinoma invasion of the urethra in 26 (13%) and prostate stroma in 16 (8%) male patients. Severe adhesions and difficulty cystectomy were encountered in 25 (12.5%) patients. Tumor was found at or close to the bladder neck in 13 (6.5%) female patients and 2 (1%) patients were found to have short mesentery. The mean follow up period was 90.02 -/+ 22.63 months. Fatality rate was 2%. Twenty-three (11.5%) patients had early complications, while 36 (23.7%) patients had late complications. Ileal conduit is still the best urinary diversion method in many patients who have bladder cancer with associated chronic medical disease or certain surgical factors that render other urinary diversion methods more difficult carry more postoperative morbidity and mortality or both. (author)

  19. Evaluation of the Melody transcatheter pulmonary valve and Ensemble delivery system for the treatment of dysfunctional right ventricle to pulmonary artery conduits.

    Science.gov (United States)

    Asnes, Jeremy; Hellenbrand, William E

    2015-11-01

    Synthetic conduits and bioprosthetic valves are used in the treatment of patients with congenital heart disease involving the right ventricular outflow tract and pulmonary valve. In-situ time-dependent degradation uniformly results in conduit and valve dysfunction. The abnormal hemodynamics imposed by valve and conduit dysfunction have been linked to exercise intolerance, arrhythmia, right heart failure, and sudden death. Starting in childhood, affected patients are subjected to repeated open-heart surgeries to restore valve function and potentially reduce morbidity and mortality. Percutaneous transcatheter pulmonary valve replacement with the Melody(®) Transcatheter Pulmonary Valve (Medtronic, Inc., Minneapolis, MN) has been performed in ?8000 patients worldwide. The valve and implant procedure provide a far less invasive means of restoring valve and conduit function and allow patients to forego multiple operations. Recent clinical trials have shown excellent and durable results in terms of valve function, relief of obstruction, and improvement in functional class up to 7 years from implant. PMID:26513599

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

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J. (Bellaire, TX); Sandberg, Chester Ledlie (Palo Alto, CA)

    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.

  1. Solution conduits as indicators of late Quaternary sea level position

    Science.gov (United States)

    Mylroie, John E.; Carew, James J.

    Solution conduits or caves can provide a measure of glacio-eustatic sea level position for the Quaternary. In high latitudes, cave deposits contain artifacts, fossils and sediments that reflect surface conditions with respect to climate. Secondary calcite deposits, most notably stalagmites, record growth episodes during ice minima and non-growth during ice maxima. They provide an indirect estimate of areal ice cover at high latitudes, and are an indirect measure of sea level. In low latitudes, stable carbonate platforms contain caves that provide a direct measure of past sea level position. Solution conduits developing in a fresh water lens will record the position of the lens and therefore sea level. As sea level fluctuates, fresh water lens horizons and conduit development horizons will shift, preserving a record of past sea level position. Cave wall rock and cave deposits can produce a chronology for given conduit positions. Secondary calcite deposits, notably stalagmites, record growth periods during sea level low stands (or ice maxima) and record growth hiatuses during flooding by sea level high stands (or ice minima); the inverse of high latitude stalagmites. Lighthouse Cave, San Salvador Island, Bahamas, records a sea level high stand at +1 to +6 m for some time period between 85,000 and 70,000 years ago, based on position and timing of conduit development; and records sea level at present elevation for some time period between 49,000 and 37,000 years ago, based on a stalagmite with a marine overgrowth.

  2. Development of conduits for the ITER central solenoid conductor

    International Nuclear Information System (INIS)

    The Japan Atomic Energy Agency has developed a JK2LB conduit for the Nb3Sn conductor of the ITER central solenoid (CS). Mechanical requirements for the CS conductor conduit are a 0.2% yield strength of more than 900 MPa and a fracture toughness KIC (J) of more than 130 MPa ?m after a compaction and aging heat treatment (650degC, 240 hours). In a previous work, it was shown that an aged JK2LB conduit has high strength and sufficient fracture toughness enough to satisfy the requirements. As the next step, work was performed to determine the specifications of the JK2LB conduit taking into account of cold work, including compaction and winding, and to simplify its fabrication process. To simulate the cold work effect with cold work of 10% and aging, mechanical tests were performed at 4.2 K on laboratory-scale (20-30 kg) ingot samples at 4.2 K. It was found that the sum of carbon and nitrogen content should be in the range from 0.11% to 0.18% to achieve the ITER mechanical requirements. To obtain a grain-sized of conduit as well as that of a small ingot sample, the appropriate solution heat-treatment temperature and holding time were studied. In order to simplify the billet production process, we confirmed the internal metallurgical qualities of a JK2LB-cast ingot. Since significant segregation was not observed, it was possible to exclude the electroslag remelting process. Based on the above achievements, full-size JK2LB conduits that satisfy the ITER mechanical requirements were fabricated. (author)

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

    Science.gov (United States)

    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... tax liability under any substantive provisions of the Internal Revenue Code. Thus, for example,...

  4. Morphometric analysis of three-dimensional networks of karst conduits

    Science.gov (United States)

    Pardo-Iguzquiza, Eulogio; Durán-Valsero, Juan J.; Rodríguez-Galiano, Victor

    2011-09-01

    The main idiosyncrasy of a typical karst system is the presence of a three-dimensional network of conduits behaving as drains in the system and being responsible of both the quick response of karst springs to rainfall events and the complex distribution of solutes in the system. A morphometric analysis of the three-dimensional geometry of conduits provides quantitative measures that can be used in a range of applications. These morphometric parameters can be used as descriptors of the underground geomorphology, they provide information on speleogenesis processes, they can be correlated with karst denudation ratios, they can be used to control the simulation of realistic stochastic karst networks of conduits, and they can be correlated with hydrogeologic behaviour of the karst system. The main purpose of this paper is to define, describe and illustrate a range of morphometric indexes and morphometric functions that can be calculated nowadays because the availability of three-dimensional topographies provided by speleological work and the availability of the computational and graphical power provided by modern computers. Some of the morphometric parameters describe the existence of preferential directions of karstification, others describe the kartification along the vertical and the possible presence of inception horizons. Other indexes describe the shape complexity of the karstic network, whilst other indexes describe spatial variability of the conduit geometry, and other parameters give account of the connectivity of the three-dimensional network. The morphometric analysis is illustrated with a three-dimensional karstic network in Southern France.

  5. Method and means for disposal of radioactive waste

    International Nuclear Information System (INIS)

    An apparatus is provided for preparing dry particulate waste material for storage within a container, comprising a source of waste, a conduit to receive the waste from the source and deliver it to a container through a detachable connection, and pressure control means to maintain the pressure in the conduit and container lower than the pressure surrounding the detachable connection. A fluid-tight vessel may surround the container and connection which is maintained at a pressure higher than that in the container and conduit. Means are provided to solidify the waste in the container

  6. Development of a scattering probability method for accurate vapor fraction measurements by neutron radiography

    CERN Document Server

    Joo, H

    1999-01-01

    Recent test results indicated drawbacks associated with the simple exponential attenuation method (SEAM) as currently applied to neutron radiography measurements to determine vapor fractions in a hydrogenous two-phase flow in a metallic conduit. The scattering component of the neutron beam intensity exiting the flow system is not adequately accounted for by SEAM, and this leads to inaccurate results. To properly account for the scattering effect, a neutron scattering probability method (SPM) is developed. The method applies a neutron-hydrogen scattering kernel to scattered thermal neutrons that leave the incident beam in narrow conduits but eventually show up elsewhere in the measurements. The SPM has been tested with known vapor (void) distributions within an acrylic disk and a water/vapor channel. The vapor (void) fractions deduced by SPM are in good agreement with the known exact values. Details of the scattering correction method and the test results are discussed.

  7. Development of a scattering probability method for accurate vapor fraction measurements by neutron radiography. Revision 1

    International Nuclear Information System (INIS)

    Recent test results indicated drawbacks associated with the simple exponential attenuation method (SEAM) as currently applied to neutron radiography measurements to determine vapor fractions in a hydrogenous two-phase flow in a metallic conduit. The scattering component of the neutron beam intensity exiting the flow system is not adequately accounted for by SEAM, and this leads to inaccurate results. To properly account for the scattering effect, a neutron scattering probability method (SPM) is developed. The method applies a neutron-hydrogen scattering kernel to scattered thermal neutrons that leave the incident beam in narrow conduits but eventually show up elsewhere in the measurements. The SPM has been tested with known vapor (void) distributions within an acrylic disk and a water/vapor channel. The vapor (void) fractions deduced by SPM are in good agreement with the known exact values. Details of the scattering correction method and the test results are discussed

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

    Science.gov (United States)

    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 (pressures from ascending magma below eventually overcome resistance to produce a rapid slip event (the "slip") along the melt-bearing slip zone, which is temporarily lubricated due to velocity-weakening. New magma below experiences the same slip event more slowly (as the magma decompresses) to produce a viscous brake and the process is repeated. This allows a fixed spatial locus that explains the repetitive drumbeat seismicity and the occurrence of "families" of similar seismic events. We conclude that stick-slip motion in volcanic conduits is a self-driving, frictional-melt-regulated force common to many dome building volcanoes.

  9. AC loss characteristics of simulated CIC-type conductors having plastic conduit

    International Nuclear Information System (INIS)

    When alternating current superconducting coils having cable-in-conduit conductors are fabricated, non-metallic conduit materials are necessary to avoid eddy current losses in the conduits. Using two kinds of non-metallic tapes made of glass fiber reinforced plastics (GFRPs) and Dyneema fiber reinforced plastics (DFRPs), we made the conductors with the GFRP conduits and DFRP conduits, and experimentally studied the total losses of the conductors. The measured results showed that the total loss of the conductor with the GFRP conduit was smaller than that with the DFRP conduit at the same value of the void ratio, the transport current, the external magnetic field, and so on. When the void ratios become high, the superconducting bundle cable can easily move in the conduit. Hence the measured total losses increased with the void ratios of the conductors

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

    Science.gov (United States)

    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.

  11. Development of the Approach by States method and thermodynamical study of a 1300 MWe PWR type reactor following a complete water loss of vapor generator alimentation with the Cathare 2 code; Developpement de la conduite APE et etude thermohydraulique d'un REP 1300 MWe suite a un accident de perte totale d'eau alimentaire des generateurs de vapeur avec le code Cathare 2

    Energy Technology Data Exchange (ETDEWEB)

    Girardin, F

    1998-06-30

    The objective of this report is to study the thermohydraulic behavior of a 1300 MWe PWR type reactor for a complete loss accident in water supplying of vapor generators. The Cathare computer code has been used in this aim. (N.C.)

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

    Science.gov (United States)

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

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Bo; Cheng, Xiaoliang; Zhang, Xiaosheng; Han, Mengdi; Liu, Wen; Zhang, Haixia, E-mail: zhang-alice@pku.edu.cn [National Key Lab of Nano/Micro Fabrication Technology, Peking University, Beijing 100871 (China)

    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 ?A/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.

  14. Injunctions against mere conduit of information protected by copyright

    DEFF Research Database (Denmark)

    Sandfeld Jakobsen, Søren; Petersen, Clement Salung

    2011-01-01

    This paper includes an in-depth analysis of EU law and Scandinavian law on injunctions against internet access providers (IAPs) performing as mere conduit of information protected by copyright. In recent Scandinavian case law, courts have granted preliminary injunctions which have caused IAPs to either shut down specific internet connections allegedly used to infringe copyright or to block access to internet content, which allegedly infringed applicable copyright rules. This paper considers some...

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

    Directory of Open Access Journals (Sweden)

    Rodrigo Guerra Sabongi

    2015-01-01

    Full Text Available 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.

  16. Free-boundary models of a meltwater conduit

    KAUST Repository

    Dallaston, Michael C.

    2014-08-01

    © 2014 AIP Publishing LLC. We analyse the cross-sectional evolution of an englacial meltwater conduit that contracts due to inward creep of the surrounding ice and expands due to melting. Making use of theoretical methods from free-boundary problems in Stokes flow and Hele-Shaw squeeze flow we construct an exact solution to the coupled problem of external viscous creep and internal heating, in which we adopt a Newtonian approximation for ice flow and an idealized uniform heat source in the conduit. This problem provides an interesting variant on standard free-boundary problems, coupling different internal and external problems through the kinematic condition at the interface. The boundary in the exact solution takes the form of an ellipse that may contract or expand (depending on the magnitudes of effective pressure and heating rate) around fixed focal points. Linear stability analysis reveals that without the melting this solution is unstable to perturbations in the shape. Melting can stabilize the interface unless the aspect ratio is too small; in that case, instabilities grow largest at the thin ends of the ellipse. The predictions are corroborated with numerical solutions using boundary integral techniques. Finally, a number of extensions to the idealized model are considered, showing that a contracting circular conduit is unstable to all modes of perturbation if melting occurs at a uniform rate around the boundary, or if the ice is modelled as a shear-thinning fluid.

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

    Science.gov (United States)

    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. PMID:22561741

  18. ESTUDIO DE LAS CONDICIONES DE EXTRACCIÓN POR ARRASTRE CON VAPOR DEL ACEITE ESENCIAL DE LAUREL DE CERA (Morella pubescens) / STUDY OF EXTRACTION CONDITIONS OF "LAUREL DE CERA" (Morella pubescens) ESSENTIAL OIL BY MEANS OF STEAM DISTILLATION

    Scientific Electronic Library Online (English)

    OSCAR, ARANGO; ANDRÉS, HURTADO; PATRICIA, CASTILLO; MÓNICA, SANTACRUZ.

    2009-12-01

    Full Text Available El laurel de cera (Morella pubescens) es un árbol que por sus características resulta muy apropiado para el control de la erosión, y cuyos frutos son utilizados por comunidades campesinas del sur de Colombia para la obtención de una cera que se emplea en el proceso de elaboración de la panela. En es [...] ta investigación se estudió el proceso de extracción del aceite esencial de las hojas del laurel de cera mediante la técnica de arrastre con vapor, y su efecto sobre la composición de los metabolitos secundarios volátiles presentes en dicho aceite. Los factores estudiados en el proceso de extracción fueron el tamaño de partícula y el tiempo de extracción, y las variables de respuesta consideradas fueron el área total del cromatograma (cuentas) como parámetro indicador de la concentración del aceite y el porcentaje relativo del componente mayoritario. Se determinó que tanto el tiempo como la interacción tiempo - tamaño de partícula tienen efectos significativos (valor de P Abstract in english Because of its characteristics, the "Laurel de Cera" tree (Morella pubescens) proves to be very appropriate for the erosion control. Its fruits are employed as a means to obtain wax that is used in the process of making Panela by rural communities settled in the southern region of Colombia. The extr [...] action process of essential oil from "Laurel de Cera" tree leaves through steam distillation and its effects over the composition of volatile secondary metabolites present were considered for the research. Particle size and extraction time were the studied factors. The chromatogram total area (counts) taken as the oil concentration indicator parameter and the relative percentage were the considered response variables. According to the previous information, it was possible to determine that the time as well as the interaction time - particle size have significant effects (P-value

  19. Simulation of particle motion in a closed conduit validated against experimental data

    Directory of Open Access Journals (Sweden)

    Dolanský Jind?ich

    2015-01-01

    Full Text Available Motion of a number of spherical particles in a closed conduit is examined by means of both simulation and experiment. The bed of the conduit is covered by stationary spherical particles of the size of the moving particles. The flow is driven by experimentally measured velocity profiles which are inputs of the simulation. Altering input velocity profiles generates various trajectory patterns. The lattice Boltzmann method (LBM based simulation is developed to study mutual interactions of the flow and the particles. The simulation enables to model both the particle motion and the fluid flow. The entropic LBM is employed to deal with the flow characterized by the high Reynolds number. The entropic modification of the LBM along with the enhanced refinement of the lattice grid yield an increase in demands on computational resources. Due to the inherently parallel nature of the LBM it can be handled by employing the Parallel Computing Toolbox (MATLAB and other transformations enabling usage of the CUDA GPU computing technology. The trajectories of the particles determined within the LBM simulation are validated against data gained from the experiments. The compatibility of the simulation results with the outputs of experimental measurements is evaluated. The accuracy of the applied approach is assessed and stability and efficiency of the simulation is also considered.

  20. Simulation of particle motion in a closed conduit validated against experimental data

    Science.gov (United States)

    Dolanský, Jind?ich

    2015-05-01

    Motion of a number of spherical particles in a closed conduit is examined by means of both simulation and experiment. The bed of the conduit is covered by stationary spherical particles of the size of the moving particles. The flow is driven by experimentally measured velocity profiles which are inputs of the simulation. Altering input velocity profiles generates various trajectory patterns. The lattice Boltzmann method (LBM) based simulation is developed to study mutual interactions of the flow and the particles. The simulation enables to model both the particle motion and the fluid flow. The entropic LBM is employed to deal with the flow characterized by the high Reynolds number. The entropic modification of the LBM along with the enhanced refinement of the lattice grid yield an increase in demands on computational resources. Due to the inherently parallel nature of the LBM it can be handled by employing the Parallel Computing Toolbox (MATLAB) and other transformations enabling usage of the CUDA GPU computing technology. The trajectories of the particles determined within the LBM simulation are validated against data gained from the experiments. The compatibility of the simulation results with the outputs of experimental measurements is evaluated. The accuracy of the applied approach is assessed and stability and efficiency of the simulation is also considered.

  1. System for continuous real time air monitoring by means of gamma spectrometry with germanium dosimeter

    International Nuclear Information System (INIS)

    Design of automatic system for real time air monitoring of radioactive particulates are relate. Recommendations are made for design and operation of sampling conduits to minimize losses. By means of experimental equipment loss of particles in long sampling conduits, minimum detectable activity and efficiency of gamma radiation detectable are evaluated. (author)

  2. ESTUDIO DE LAS CONDICIONES DE EXTRACCIÓN POR ARRASTRE CON VAPOR DEL ACEITE ESENCIAL DE LAUREL DE CERA (Morella pubescens STUDY OF EXTRACTION CONDITIONS OF "LAUREL DE CERA" (Morella pubescens ESSENTIAL OIL BY MEANS OF STEAM DISTILLATION

    Directory of Open Access Journals (Sweden)

    OSCAR ARANGO

    2009-12-01

    Full Text Available El laurel de cera (Morella pubescens es un árbol que por sus características resulta muy apropiado para el control de la erosión, y cuyos frutos son utilizados por comunidades campesinas del sur de Colombia para la obtención de una cera que se emplea en el proceso de elaboración de la panela. En esta investigación se estudió el proceso de extracción del aceite esencial de las hojas del laurel de cera mediante la técnica de arrastre con vapor, y su efecto sobre la composición de los metabolitos secundarios volátiles presentes en dicho aceite. Los factores estudiados en el proceso de extracción fueron el tamaño de partícula y el tiempo de extracción, y las variables de respuesta consideradas fueron el área total del cromatograma (cuentas como parámetro indicador de la concentración del aceite y el porcentaje relativo del componente mayoritario. Se determinó que tanto el tiempo como la interacción tiempo - tamaño de partícula tienen efectos significativos (valor de PBecause of its characteristics, the "Laurel de Cera" tree (Morella pubescens proves to be very appropriate for the erosion control. Its fruits are employed as a means to obtain wax that is used in the process of making Panela by rural communities settled in the southern region of Colombia. The extraction process of essential oil from "Laurel de Cera" tree leaves through steam distillation and its effects over the composition of volatile secondary metabolites present were considered for the research. Particle size and extraction time were the studied factors. The chromatogram total area (counts taken as the oil concentration indicator parameter and the relative percentage were the considered response variables. According to the previous information, it was possible to determine that the time as well as the interaction time - particle size have significant effects (P-value <0,05 over the essential oil's concentration. It was also possible to observe a meaningful increment in the chromatogram's area for the majority component when the extraction time was increased. The identification of the volatile secondary metabolites present in the essential oil was carried out through a gas chromatography/mass spectrometry (GC-MS. Such procedure gave as results trans caryophyllene (23,3%, ?-selinene (10,7%, ?-selinene (10,0% caryophyllene oxide (4,8%, seline-3,7(11-diene (3,3% and ?-elemene (2,6% as majority components. These compounds' biological activities allow thinking that the essential oil from the "Laurel de Cera" tree leaves could be of great interest for the pharmabusiness and the cosmetic industries.

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

    Science.gov (United States)

    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.

  4. Hydraulic and geological factors influencing conduit flow depth

    OpenAIRE

    Worthington, S.R.H.

    2005-01-01

    There has much been speculation as to whether cave formation should occur at, above, or below the water table, but a satisfactory explanation has been lacking until recently. The last 50 years has seen extensive mapping of caves both above and, more recently, below the water table. It is now becoming apparent that there are systematic differences in depth of flow between different areas and that conduit flow to depths >100m below the water table is not uncommon. Such deep flow is facilitated ...

  5. Detection of intra-atrial conduit leakage by transesophageal echocardiography.

    Science.gov (United States)

    Wang, T L; Lai, L P; Kuan, P

    1993-09-01

    A 19-year-old male patient who had undergone total cavo-pulmonary connection for complex congenital cyanotic heart disease with partial anomalous pulmonary venous return, was found to have persistent postoperative cyanosis. Transesophageal echocardiography disclosed leakage of the intra-atrial Gortex conduit with a right-to-left shunt. Prompt re-do operation confirmed the site of the leakage which was successfully repaired. Intraoperative transesophageal echocardiography may be indicated so as to avoid a secondary open-chest procedure for this complication. PMID:8282444

  6. Heating-induced flows in cable-in-conduit conductors

    International Nuclear Information System (INIS)

    Hoenig et al and Miller et al have both reported high stability margins for cable-in-conduit conductors cooled by stationary supercritical helium. Miller et al proposed that strong flows induced in the helium in the early stages of recovery enhanced heat transfer and greatly increased the stability margin over what had been expected for stationary helium. In this memorandum, the flow and pressure transients induced in initially stationary helium by energy transfers typical of those associated with conductor recovery (50 to 200 mJ cm-3 in 10 to 20 msec) are calculated

  7. The Malone Antegrade Continence Enema (MACE principle in children: is it important if the conduit is implanted in the left or the right colon?

    Directory of Open Access Journals (Sweden)

    Karine F. Meyer

    2008-03-01

    Full Text Available OBJECTIVE: The aim of the study was to determine which was the optimal side for the conduit to be placed (right or left colon for antegrade continence enema implantation. MATERIALS AND METHODS: Between July 1999 and March 2006, 31 patients underwent the construction of a catheterizable conduit using the Malone principle (MACE In 22 cases the conduit was re-implanted in the right colon and in 9 cases in the left colon. There were 20 male patients and 11 female patients, with a mean age of 10.23 years. The follow-up period varied from 3 from 83 months (average 25 months. Right and left implantation of the conduit in the colon were compared with regards to the presence of complications, volume of the solution utilized, frequency of colonic lavage, time needed for performing the enema, and degree of satisfaction. RESULTS: One patient with the conduit in the right colon, using the appendix, lost the mechanism after two month follow-up. Thirty patients remain clean and are all capable of performing self-catheterization. No statistically significant differences were found between the groups regarding the variables studied: complications (p = 1.000, solution volume (p = 0.996, time required (p = 0.790 and patient's rating (p = 0.670. The lavage frequency required for patients with the conduit in the right colon may be lower. CONCLUSION: The MACE principle was considered effective for treating fecal retention and leaks, independent of the implantation site. The success of this surgery appears to be directly related to the patient's motivation and not to the technique utilized.

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

    International Nuclear Information System (INIS)

    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 111In-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

  9. Tensile and fatigue qualification testing of ITER-CS conduit alloy JK2LB

    Science.gov (United States)

    Walsh, R. P.; McRae, D. M.; Han, K.; Martovetsky, N. N.

    2015-12-01

    The ITER Central Solenoid (CS) coils utilize cable-in-conduit conductor (CICC) and the conduit alloy is JK2LB. The production grade conduit alloy (and it's welds) must meet strict requirements for strength, toughness, fatigue crack resistance, and fabricability. The conduit alloy must retain good mechanical properties after additional fabrication steps such as welding, coil winding strain and exposure to the Nb3Sn superconductor's reaction heat treatment. Here we present data from cryogenic tensile, fracture toughness, fatigue crack growth rate, and axial fatigue tests of JK2LB alloy and conduit butt welds, before and after the exposure to the reaction heat treatment. The tests of specimens removed directly from the conduit provide confirmation of the materials properties and the effect of the cold work and aging. The 4 K fatigue performance is extremely important to the reliability of the CS and is covered both by axial cyclic fatigue tests and the fatigue crack growth rate measurements.

  10. Ground water flux distribution between matrix, fractures, and conduits: constraints on modeling

    OpenAIRE

    White, W. B.; White, E.L.

    2005-01-01

    Calculations are presented to show the relative contribution of the matrix, fracture, and conduit permeability to the overall flow of ground water through a karst aquifer. The conceptual model is a cross-section spanning the full width and thickness of the aquifer. A constant, but adjustable head is assumed. The rock matrix is characterized by an adjustable hydraulic conductivity. Varying proportions of fractures and conduits of adjustable fracture apertures and conduit diameters were the...

  11. Nanofibrous nerve conduits for repair of 30-mm-long sciatic nerve defects

    OpenAIRE

    Biazar, Esmaeil; Keshel, Saeed Heidari; Pouya, Majid; Rad, Hadi; Nava, Melody Omrani; Azarbakhsh, Mohammad; Hooshmand, Shirin

    2013-01-01

    It has been confirmed that nanofibrous poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nerve conduit 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 conduit to bridge a 30-mm-long gap in the rat sciatic nerve. At 4 months after nerve conduit implantation, regenerated nerves were cally observed and histologicall...

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

    Science.gov (United States)

    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.

  13. Causes and consequences of conduit wall permeability changes during explosive eruptions

    Science.gov (United States)

    Rust, Alison; Hanson, Jonathan

    2015-04-01

    Magmatic volatiles, and in some cases external water, drive explosive volcanic eruptions and so the permeability of magma and conduit wall rocks can modulate the style and intensity of eruptions. Both modelling of eruption dynamics and field studies of lithic clasts indicate that fragmentation levels during explosive silicic eruptions commonly reach depths of kilometres. An important consequence is that substantial deviations from lithostatic pressure are sustained in the conduit during eruption, which, according to finite element modelling, are sufficient to damage a substantial volume of rock around the conduit. Underpressured regions will be susceptible to conduit erosion, widening the conduit; field data provide constraints on erosion rates and erosion depths where subsurface stratigraphy is known. Damage to wall rocks will also increase the rock permeability adjacent to the conduit, which could significantly affect magmatic degassing during and between eruptions. The degree to which external water can interact with magma in the conduit will also depend on wall rock permeability and spatial and temporal variations in pressure. When a major magmatic eruption ceases, deep magma is likely to ascend to fill the lower conduit, and the upper conduit may partially collapse forming vertically extensive breccia. Subvolcanic rocks exposed by exploration and mining of porphyry copper deposits (PCDs) and associated alteration and breccias may provide further field constraints on these models. Although syn- and post-mineralization explosive eruptions likely ruin potential PCDs, earlier eruptions might make space for vertical shallow intrusions and help establish permeable regions conducive to focussing of magmatic fluids required for PCD generation.

  14. Uranium AVLIS vaporizer development

    International Nuclear Information System (INIS)

    A uranium vaporization system has been developed to efficiently produce the large quantities of atomic uranium vapor that are required for an economic Atomic Vapor Laser Isotope Separation (AVLIS) process. The vapor produced is well collimated and electronically cold. Vapor is produced by high energy electrons which are magnetically steered to the melt surface. Contouring of magnetic fields helps to optimally format the primary electrons and to contain backscattered electrons. A highly compact electron beam system has been developed to facilitate modular packaging of vaporizer components. Electron beam system power will be provided by high power switching power supplies. These power supplies, which are nearing completion at LLNL, have high electrical efficiency and offer excellent protection against high voltage arcdowns. Vapor density, composition, and quality are monitored by laser absorption spectroscopy. All laser and optical components are mounted outside the process chamber. The monitoring system is nonintrusive and is designed to survive long duration operation at high vaporization rates. Computer processing of laser data permits real time monitoring of vaporizer performance. Vapor density and composition are input to an internal model based controller which regulates feed rate and power to maintain desired process conditions. All vaporizer system components are in the final stages of development. Vaporization rate and vapor quality requirements have been met. Current efforts are directed toward reliability improvement and cost reduction. Computer controlled, high vaporization rate operation of the integrated vaporizer system has been demonstrated during uranium enrichment runs in excess of 100 hours duration

  15. Raman water vapor lidar calibration

    Science.gov (United States)

    Landulfo, E.; Da Costa, R. F.; Torres, A. S.; Lopes, F. J. S.; Whiteman, D. N.; Venable, D. D.

    2009-09-01

    We show here new results of a Raman LIDAR calibration methodology effort putting emphasis in the assessment of the cross-section ratio between water vapor and nitrogen by the use of a calibrated NIST traceable tungsten lamp. Therein we give a step by step procedure of how to employ such equipment by means of a mapping/scanning procedure over the receiving optics of a water vapor Raman LIDAR. This methodology has been independently used at Howard University Raman LIDAR and at IPEN Raman LIDAR what strongly supports its reproducibility and points towards an independently calibration methodology to be carried on within an experiment routine.

  16. Arctic Water Vapor Characteristics from Rawinsondes

    Data.gov (United States)

    National Aeronautics and Space Administration — A gridded climatological monthly-mean data base of Arctic water vapor characteristics has been assembled by combining fixed station data with data from soundings...

  17. 33 CFR 157.132 - Cargo tanks: Hydrocarbon vapor emissions.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Cargo tanks: Hydrocarbon vapor... § 157.132 Cargo tanks: Hydrocarbon vapor emissions. Each tank vessel having a COW system under § 157.10a... must have— (a) A means to discharge hydrocarbon vapors from each cargo tank that is ballasted to...

  18. Palliative urinary conduit diversion in cases of intolerable urinary discomfort

    Energy Technology Data Exchange (ETDEWEB)

    Lyndrup, J.; Sorensen, B.L.

    1983-12-01

    Fifteen patients with incurable gynecological cancers, all primary radiation treated and all having severe urinary discomfort due to urinary tract injuries were retrospectively examined after urinary conduit diversion. All have been followed-up until termination or until all survivors had lived for 6 months after the operation. Twelve of the 15 were discharged from the hospital, 10 of whom survived the first 6 months. Of those discharged 82% of the cumulated sum of postoperative observations days was spent out of the hospital. At the end of the observation period nine patients had been supplied with a colostomy as well, thus having double stomas. All six patients still alive declared in retrospect that given the choice again, they would still be willing to undergo the operation.

  19. Palliative urinary conduit diversion in cases of intolerable urinary discomfort

    International Nuclear Information System (INIS)

    Fifteen patients with incurable gynecological cancers, all primary radiation treated and all having severe urinary discomfort due to urinary tract injuries were retrospectively examined after urinary conduit diversion. All have been followed-up until termination or until all survivors had lived for 6 months after the operation. Twelve of the 15 were discharged from the hospital, 10 of whom survived the first 6 months. Of those discharged 82% of the cumulated sum of postoperative observations days was spent out of the hospital. At the end of the observation period nine patients had been supplied with a colostomy as well, thus having double stomas. All six patients still alive declared in retrospect that given the choice again, they would still be willing to undergo the operation

  20. Nerve conduit using fascia-wrapped fibrocollagenous tube.

    Science.gov (United States)

    Watanabe, K; Tsukagoshi, T; Kuroda, M; Hosaka, Y

    2001-07-01

    The purpose of this study was to evaluate the application of autogenous fascia as a framework of a fibrocollagen tube for a nerve conduit in Japanese white rabbits. The fascia was wrapped with a double layer around a silicone rod 3.0 mm in diameter. After the implantation of the fascia-wrapped silicone rod into a subcutaneous pocket for 2 weeks, a 3.0 x 30-mm fascia-wrapped fibrocollagen (FFC) tube was prepared. With microvascular techniques, the tube was interposed into a right sciatic nerve gap which was 25 mm long. The results of nerve regeneration in the FFC tube group, in particular, the formation of epineurium, were able to stand comparison with the results of a control group under both histologic and electron micrographic examination. PMID:11499471

  1. 78 FR 61985 - City of Astoria, Oregon; Notice of Preliminary Determination of a Qualifying Conduit Hydropower...

    Science.gov (United States)

    2013-10-09

    ... Conduit 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 conduit hydropower facility, pursuant to section 30 of the Federal Power Act, as amended by section 4 of the...

  2. 78 FR 69847 - North Side Canal Company; Notice of Preliminary Determination of a Qualifying Conduit Hydropower...

    Science.gov (United States)

    2013-11-21

    ... Qualifying Conduit 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 conduit hydropower facility, pursuant to section 30 of the Federal Power Act, as amended by section 4 of the Hydropower...

  3. 78 FR 56872 - City of Barre, Vermont; Notice of Preliminary Determination of a Qualifying Conduit Hydropower...

    Science.gov (United States)

    2013-09-16

    ... Conduit Hydropower Facility and Soliciting Comments and Motions To Intervene On August 29, 2013, City of Barre, Vermont filed a notice of intent to construct a qualifying conduit hydropower facility, pursuant to section 30 of the Federal Power Act, as amended by section 4 of the Hydropower...

  4. 78 FR 62351 - North Side Canal Company; Notice of Preliminary Determination of a Qualifying Conduit Hydropower...

    Science.gov (United States)

    2013-10-18

    ... Qualifying Conduit Hydropower Facility and Soliciting Comments and Motions To Intervene On October 3, 2013, North Side Canal Company, filed a notice of intent to construct a qualifying conduit hydropower facility, pursuant to section 30 of the Federal Power Act, as amended by section 4 of the Hydropower...

  5. 78 FR 66355 - Pleasant Grove City, UT; Notice of Preliminary Determination of a Qualifying Conduit Hydropower...

    Science.gov (United States)

    2013-11-05

    ... Conduit Hydropower Facility and Soliciting Comments and Motions To Intervene On October 22, 2013, as... a qualifying conduit 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 120 kW Battle...

  6. 78 FR 53752 - City of Sandpoint, Idaho; Notice of Preliminary Determination of a Qualifying Conduit Hydropower...

    Science.gov (United States)

    2013-08-30

    ... Qualifying Conduit Hydropower Facility and Soliciting Comments and Motions To Intervene On August 15, 2013, City of Sandpoint, Idaho filed a notice of intent to construct a qualifying conduit hydropower facility, pursuant to section 30 of the Federal Power Act, as amended by section 4 of the Hydropower...

  7. 78 FR 61987 - Corbett Water District; Notice of Preliminary Determination of a Qualifying Conduit Hydropower...

    Science.gov (United States)

    2013-10-09

    ... Conduit 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 conduit hydropower facility, pursuant to section 30 of the Federal Power Act, as amended by section 4 of the Hydropower...

  8. A one-dimensional heat-transport model for conduit flow in karst aquifers

    Science.gov (United States)

    Long, A.J.; Gilcrease, P.C.

    2009-01-01

    A one-dimensional heat-transport model for conduit 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 conduit 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 conduit. Heat transport in the conduit 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 conduit 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 conduit and a pumped well open to the Madison aquifer in western South Dakota. The simulated conduit-flow fraction to the well ranged from 2% to 31% of total flow, and simulated conduit velocity ranged from 44 to 353 m/d.

  9. Hydraulic transients in pumping station-main conduit - Cooling tower systems

    International Nuclear Information System (INIS)

    The paper presented a method of starting up a pump with a partially filled main conduit allows to avoided filling the conduit with a low head and draining the pipeline followed by rotation of the pump in the opposite direction. This provides reduction of dynamic loads on the system elements and increases the reliability and time of the work

  10. In vivo studies of silk based gold nano-composite conduits for functional peripheral nerve regeneration.

    Science.gov (United States)

    Das, Suradip; Sharma, Manav; Saharia, Dhiren; Sarma, Kushal Konwar; Sarma, Monalisa Goswami; Borthakur, Bibhuti Bhusan; Bora, Utpal

    2015-09-01

    We report a novel silk-gold nanocomposite based nerve conduit successfully tested in a neurotmesis grade sciatic nerve injury model in rats over a period of eighteen months. The conduit 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 conduits 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 conduit implantation by recording motor unit potentials (MUPs) through needle electromyogram. Pre-seeding the conduits with Schwann cells enhanced myelination of the regenerated tissue. Histo-morphometric and electrophysiological studies proved that the nanocomposite based conduits 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 ?V) exhibited by the animals implanted with Schwann cell loaded nerve conduits in the present study are superior to those observed in previous reports with synthetic materials as well as collagen based nerve conduits. 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. PMID:26026910

  11. 26 CFR 1.881-4 - Recordkeeping requirements concerning conduit financing arrangements.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 9 2010-04-01 2010-04-01 false Recordkeeping requirements concerning conduit financing arrangements. 1.881-4 Section 1.881-4 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE... requirements concerning conduit financing arrangements. (a) Scope. This section provides rules for...

  12. MR jet velocity mapping for assessment of conduit and valve stenosis and aortic coarctation

    International Nuclear Information System (INIS)

    This paper assesses short echo time MR jet velocity mapping as a means of measuring poststenotic jet velocities in vitro and in patients. MR jet velocity mapping was performed with a Picker 0.5-T machine and the field even-echo rephasing sequence with a 3.6-msec echo time, in stenotic flow phantoms and in 49 patients (mean age, 31 years; range, 12-72 years) with stenoses of valved conduits (n = 22), native heart valves (n = 123), and aortic coarctation (n = 15). Where possible, results were compared with those available from Doppler US and catheter studies. MR velocity maps clearly demonstrated the shape and location of jets, and velocity measurements correlated well with Doppler measurements up to 6 m/sec in vitro (r = .996). In patients, jet velocities up to 5.5 m/sec were mapped, and for 21 cases in which comparison was possible, agreement with Doppler was good (means of peak velocity measurements, 2.7 m/sec; standard deviation of differences, 0.2 m/sec). Unclear velocity maps were attributed to slight misplacement of the image plane in seven cases

  13. Temperature control of a steam generator by means of an hybrid system PID-RLC; Control de las temperaturas de un generador de vapor mediante un sistema hibrido PID-RLC

    Energy Technology Data Exchange (ETDEWEB)

    Palomares Gonzalez, Daniel; Garcia Mendoza, Raul [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1990-12-31

    A description is made of the design and evaluation of an hybrid control system, formed by a quadratic gaussian linear regulator (QLR) and proportional integral derivative (PID) type regulators. This scheme is used to control the reheater and secondary superheater steam temperatures of a steam generator model with a maximum capacity of 2,150,000 pounds per hour. Once applied to the model of a 300 MW steam power plant, this system showed better results than the traditional schemes and inclusively better than some modern control schemes. This fact characterizes it as a high potential system to be applied to steam power plants. [Espanol] Se describe el diseno y la evaluacion de un sistema de control hibrido, formado por un regulador lineal cuadratico gaussiano (RLC) y reguladores tipo proporcional integral derivativo (PID). Este esquema se utiliza para controlar las temperaturas de vapor del recalentador y sobrecalentador secundario del modelo de un generador de vapor con capacidad maxima de 2,150,000 libras por hora. Una vez aplicado al modelo de una unidad termoelectrica de 300 MW, este sistema produjo mejores resultados que los esquemas tradicionales e incluso mejores que algunos esquemas de control moderno. Esto lo caracteriza como un sistema con un alto potencial para aplicarse a unidades termoelectricas.

  14. Magnetic losses and reactance change by the use of metallic conduit in electrical installations; Perdidas magneticas y cambio de reactancia por la tuberia metalica en instalaciones electricas

    Energy Technology Data Exchange (ETDEWEB)

    Campero Littlewood, Eduardo; Castaneda D, Miguel; Castulo A, Roberto; Bratu Serban, Neagu [Universidad Autonoma Metropolitana-Azcapotzalco, Mexico, D. F. (Mexico)

    1996-12-31

    In this paper are presented the results obtained in the measurement of magnetic losses in metallic conduits in electric installations. The losses for parasitic currents and by hysteresis were obtained in different conditions of magnetic density, caused by the net current resulting from the sum of all the currents of all the conductors that travel along the conduit. These currents are named differential currents, and the conditions in which they appear in the electric installations are described. The magnetic induction phenomenon that occurs in metallic conduit is briefly described and the basic concepts that describe it. A theoretical-experimental methodology is offered to quantify the energy losses by parasitic currents and by the metal magnetization in these metallic conduits. At the same time, the impact of these differential currents impact in the reactance of the electric installation is quantified. The obtained results for twelve conduits of different diameters and different wall thickness are shown. A comparison analysis is made with the reported results in a previous article, where the losses were estimated by means of the temperature rise measurement of the metallic wall. [Espanol] En este articulo se presentan los resultados obtenidos en la medicion de perdidas magneticas en tuberias conduit (metalicas) en instalaciones electricas. Las perdidas por corrientes parasitas y por histeresis se obtuvieron para diferentes condiciones de densidad magnetica, provocada por la corriente neta resultante de la suma de las corrientes de todos los conductores que viajan por la tuberia. A estas corrientes se les designa corrientes diferenciales y se describen las condiciones en las que estas aparecen en las instalaciones electricas. Se explica brevemente el fenomeno de induccion magnetica que se presenta en las tuberias metalicas y los conceptos basicos que la describen. Se plantea una metodologia teorico-experiemental para cuantificar las perdidas de energia, por corrientes parasitas y por la magnetizacion del metal en estas tuberias conduit. Al mismo tiempo se cuantifica el impacto de estas corrientes diferenciales en la reactancia de la instalacion electrica. Se muestran los resultados obtenidos para doce tubos de diferente diametro y espesor de pared. Se hace un analisis comparativo con los resultados reportados en un articulo anterior, donde las perdidas se estimaron mediante la medicion del incremento de temperatura de la pared metalica.

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

    Science.gov (United States)

    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 hydrogel. This indicates return of some feeling to the limb via the fully-configured conduit. Immunohistochemical analysis of the implanted conduits removed from the rats after the four-week implantation period confirmed the presence of myelinated axons within the conduit and distal to the site of implantation, further supporting that the conduit promoted nerve repair over this period of time. This study describes the design considerations and fabrication of a novel multicomponent, multimodal bio-engineered synthetic conduit for peripheral nerve repair.

  16. A novel bioactive nerve conduit for the repair of peripheral nerve injury

    Science.gov (United States)

    Li, Bin-bin; Yin, Yi-xia; Yan, Qiong-jiao; Wang, Xin-yu; Li, Shi-pu

    2016-01-01

    The use of a nerve conduit 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 conduit 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 conduit was compared to that of PDLLA-only conduit 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 conduit, the nerve fibers in the PDLLA-based bioactive nerve conduit 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 conduit is a promising strategy for repair after sciatic nerve injury.

  17. Relative Importance of Karst-Conduit Hyporheic Zones Co-occuring at Different Spatial Scales

    Science.gov (United States)

    Henry, K.; Wilson, J. L.

    2014-12-01

    Hyporheic zones at the margin of karst conduits occur at different spatial scales, from those associated with the smallest scales (cm) of conduit-wall topography (e.g., scallops) to large-scale (100 m) conduit sinuosity, and to even larger conduit network patterns. Hyporheic flows are believed to influence the processing of nutrients and dissolved organic carbon from the conduit flow, the evolution of karst-water chemistry, the reaction and sequestration of contaminants, and speleogenesis. Multiple spatial scales of hyporheic interaction lead to a wide distribution of hyporheic flow path lengths, residence times, and opportunities for both abiotic and microbially-mediated reactions of various kinetics. Using mathematical modeling we examine hyporheic flows for a single karst conduit with two different scales of flow disturbance: wall topography at the sub-meter scale and sinuosity at the scale of 10's of meters. By varying the amplitude of each disturbance we examine changes in hyporheic flow magnitude, paths, residence times, and other metrics. We test the hypothesis that while sinuosity-driven hyporheic flow occupies the greatest volume of karst matrix rock, with the longest residence times, the much smaller volume of topographically-driven hyporheic flow is more important because it turns over far more conduit flow and does so with much shorter and possibly more important residence times.

  18. Fluid-Rock Dynamic Interaction in Magmatic Conduits: Modelling Transients Using an Analytical Solution

    Science.gov (United States)

    Arciniega-Ceballos, Alejandra; Scheu, Bettina; Sanchez-Sesma, Francisco; Dingwell, Donald

    2014-05-01

    We compute transients fluid-rock dynamic interaction in a fluid driven axisymmetric conduit embedded in an infinite, homogeneous elastic space. Both fluid and solid are dynamically coupled fulfilling continuity of velocities and radial stresses at the conduit's wall. The calculation model considers the viscosity as a key parameter leading to non-linear scheme. A pressure transient at a point of the conduit, that perturbs a steady flow of incompressible viscous fluid, produces the interaction between the fluid and motion at the conduit's walls. The fluid motion induces the elastic response of the conduit forcing it to oscillate radially. The fluid-filled conduit dynamics is governed by three second-order, ordinary non-linear differential equations, which are solved numerically by applying a fifth-order Runge-Kutta scheme. Boundary conditions satisfy the Bernoulli's principle allowing coupling several pipe segments which may present smooth variation in fluid properties. The nature of the source involves different pressure excitations functions including those measuring during simulations of gas burst and fragmentation of volcanic rocks under controlled laboratory conditions. Far-field velocity synthetics radiated by motion of the conduit's walls and fluid flows ascending to the surface, display characteristic waveforms and frequency content that are similar to those of long-period signals and tremor observed at active volcanoes. Results suggest that transient fluid flow induced oscillations may explain long-period and tremor signals. Advantages and limitations of this approach are discussed.

  19. The Role of Oxygen Partial Pressure in Controlling the Phase Composition of La1-x Sr x Co y Fe1-y O3-δ Oxygen Transport Membranes Manufactured by Means of Plasma Spray-Physical Vapor Deposition

    Science.gov (United States)

    Marcano, D.; Mauer, G.; Sohn, Y. J.; Vaßen, R.; Garcia-Fayos, J.; Serra, J. M.

    2016-02-01

    La0.58Sr0.4Co0.2Fe0.8O3- δ (LSCF) deposited on a metallic porous support by plasma spray-physical vapor deposition is a promising candidate for oxygen-permeation membranes. Ionic transport properties are regarded to depend on the fraction of perovskite phase present in the membrane. However, during processing, the LSCF powder decomposes into perovskite and secondary phases. In order to improve the ionic transport properties of the membranes, spraying was carried out at different oxygen partial pressures p(O2). It was found that coatings deposited at lower and higher oxygen partial pressures consist of 70% cubic/26% rhombohedral and 61% cubic/35% rhombohedral perovskite phases, respectively. During annealing, the formation of non-perovskite phases is driven by oxygen non-stoichiometry. The amount of oxygen added during spraying can be used to increase the perovskite phase fraction and suppress the formation of non-perovskite phases.

  20. Obstruction of an ileal urinary conduit in an incarcerated right inguinal hernia.

    Science.gov (United States)

    Young, M J; Weston, P M T

    2015-04-01

    We present the case of a 72-year-old man with a history of anuria from his ileal conduit 15 months following its formation. That conduit had become incarcerated in a right-sided ingunial hernia. The patient presented with anuria and an acute kidney injury. A clincal diagnosis of an incarcerated hernia was made, and he was taken to theatre for reduction and repair of the hernia. On removal of the conduit from the hernial sac, it began to drain immediately. He made a full recovery, with normalisation of his renal function. PMID:26491738

  1. Totally biological composite aortic stentless valved conduit for aortic root replacement: 10-year experience

    OpenAIRE

    Meduoye Ayo; Ferreira Ignacio; Galiñanes Manuel; Sosnowski Andrzej

    2011-01-01

    Abstract Objectives To retrospectively analyze the clinical outcome of a totally biological composite stentless aortic valved conduit (No-React® BioConduit) implanted using the Bentall procedure over ten years in a single centre. Methods Between 27/10/99 and 19/01/08, the No-React® BioConduit composite graft was implanted in 67 patients. Data on these patients were collected from the in-hospital database, from patient notes and from questionnaires. A cohort of patients had 2D-echocardiogram w...

  2. A nonlinear analysis methodology for the one hole malleable iron conduit clamp

    International Nuclear Information System (INIS)

    A generalized nonlinear finite element methodology for determining the load-deflection behavior of a malleable iron one hole conduit clamp is developed. This clamp is used to support electrical-conduit in industry and nuclear power plants. Two different types of one hole malleable iron conduit clamps are analyzed using two dimensional plane stress finite element models. The analysis used the following nonlinear options: large displacement option, interface option, plasticity option, and bilinear material stress-strain capabilities. The analytical methodology gives similar results to those measured in actual clamp tests

  3. Transcatheter Pulmonary Valve Replacement for Right Ventricular Outflow Tract Conduit Dysfunction After the Ross Procedure

    DEFF Research Database (Denmark)

    Gillespie, Matthew J; McElhinney, Doff B; Kreutzer, Jacqueline; Hellenbrand, William E; El-Said, Howaida; Ewert, Peter; Rhodes, John F; Søndergaard, Lars; Jones, Thomas K

    2015-01-01

    BACKGROUND: Right ventricular outflow tract (RVOT) conduit dysfunction is a limitation of the Ross procedure. Transcatheter pulmonary valve replacement (TPVR) could alter the impact of conduit dysfunction and the risk-benefit balance for the Ross procedure. METHODS: Retrospective review of...... databases from 3 prospective Melody TPV (Medtronic Inc, Minneapolis, MN) trials. RESULTS: Among 358 patients who were catheterized with the intent to implant a Melody TPV for RVOT conduit stenosis or regurgitation (PR) as part of 3 prospective multicenter studies, 67 (19%) had a prior Ross procedure. Of...

  4. Flambage vertical des conduites en souillées Vertical Buckling of Buried Pipes

    OpenAIRE

    Bournazel C.

    2006-01-01

    Si l'apparition d'un flambage vertical des conduites rigides enfouies dans une tranchée est un phénomène assez rare, il peut ne pas en être de même pour des conduites flexibles dont les propriétés mécaniques sont de nature différente. Une étude théorique et expérimentale, ayant pour but de proposer une méthode analytique de calcul de l'apparition du flambage et de son évolution sous l'effet de la pression interne, a été réalisée. II apparaît que les conduites flexibles actuelles sont très sen...

  5. Data Transfer via Alternative Conduits: Using Fluid Networks

    Directory of Open Access Journals (Sweden)

    Charles Willow

    2012-11-01

    Full Text Available Digital convergence has reshaped a gamut of industry demographics in the 21C, comprised of cloud computing, healthcare, pharmaceutical, consumer supplies, government, defense, manufacturing, entertainment, and even on-line education, among many others.   At the center of the web-convergence lies the problem of network bandwidth limitation.  Traditionally, research has focused on two major resolution strategies in parallel:  data compression to minimize the network traffic (i.e. algorithmic; software and alternative conduit for data transfer such as wireless (i.e. infrastructural; hardware.Building a network infrastructure is extremely costly.   In addition, maintenance and upgrade costs may be prohibitive, given the U.S. consumer demographics.   To this end, the emphasis is placed on seeking existing infrastructure which connects business and residential entities.The objective of this research, therefore, is to seek the possibility and feasibility of (digital data transfers via the extensive water and/or sewer network(s, while minimizing structural modifications to the existing infrastructure.   To date, sonar has been proven to be effective.   If successful, the value of this intellectual property may be immeasurable.

  6. A Cable-in-Conduit Superconductor for Pulsed Accelerator Magnets

    CERN Document Server

    Bottura, L; Fischer, E; Kauschke, M; Moritz, G; Vysotsky, V S; Sytnikov, V E; Wilson, M

    2005-01-01

    Superconducting magnets for future accelerators such as the SIS-100 ring of the International Accelerator Facility at GSI-Darmstadt, or a superconducting injector at the LHC, require that the magnetic field is pulsed with high repetition rate and high reliability over periods of several years. As an example the SIS-100 at the IAF is planned to be operated up to 2 T at 4 T/s for more than 100 millions cycles. Achieving these objectives requires that the superconductor has an excellent mechanical stability as well as a sufficient energy margin to tolerate foreseen and unforeseen energy inputs. In addition the cryogenic loss must be controlled at low levels, while the field errors due to coupling currents must be compatible with the beam dynamics requirements. In this paper we describe a cable-in-conduit design that is suitable for the challenging operating conditions described above, we give the expected performances and report on the on-going manufacturing demonstration and planned supporting tests.

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

    Science.gov (United States)

    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.

  8. Injunctions against mere conduit of information protected by copyright

    DEFF Research Database (Denmark)

    Sandfeld Jakobsen, SØren; Petersen, Clement Salung

    2011-01-01

    This paper includes an in-depth analysis of EU law and Scandinavian law on injunctions against internet access providers (IAPs) performing as mere conduit of information protected by copyright. In recent Scandinavian case law, courts have granted preliminary injunctions which have caused IAPs to either shut down specific internet connections allegedly used to infringe copyright or to block access to internet content, which allegedly infringed applicable copyright rules. This paper considers some significant legal challenges, which are emerging in the wake of this case law, and which should attract attention in all European member states. Firstly, it is shown that rules on preliminary injunctions are generally unable to safeguard the significant legitimate interests of third parties, which may be harmed by such relief, and that a proper implementation of Art. 8(3) of the Infosoc Directive requires rules, which take into due consideration the special aspects related to enforcement of copyright on the internet through IAPs. Secondly, it is shown that the termination of internet connections and the blocking of access to internet content may not support the public policies behind copyright law and also may restrict the freedom of expression under European human rights law. The analysis is based on a brief account for the relevant EU Directives, the implementation of these Directives in the Scandinavian countries and the Scandinavian case law regarding use of injunctions against IAPs to enforce copyright on the internet.

  9. CFD modeling of ITER cable-in-conduit superconductors

    International Nuclear Information System (INIS)

    In the first paper of this series, we proposed a novel approach to help understand some of the complex processes occurring in dual-channel cable-in-conduit conductors (CICC) as used in the superconducting coils of the international thermonuclear experimental reactor (ITER): the constitutive relations including transport coefficients needed in input by standard global 1D tools for the analysis of thermal-hydraulic transients in ITER coils, e.g., the Mithrandir/M and M code, are derived from local 3D analysis. A first validation of the model was performed showing very good agreement with available experimental data from different applications. The same advanced computational fluid dynamics (CFD) tool, the FLUENT code, including sophisticated turbulence models, is used here to compute the pressure drop corresponding to an imposed mass flow rate in several geometries relevant for the central channel of the ITER CICC. The validation is extended to include more ITER-relevant conditions showing good accuracy with error bars on the friction factor ∼±15%. We then apply the validated model to the study of the expected dependencies of the pressure drop in the central channel of an ITER CICC on the size of the gap and on the diameter of the delimiting spiral

  10. Effect of Multiwall Carbon Nanotube Reinforcement on Coaxially Extruded Cellular Vascular Conduits

    Science.gov (United States)

    Zhang, Yahui; Yu, Yin; Dolati, Farzaneh; Ozbolat, Ibrahim T

    2014-01-01

    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 conduits were fabricated through a coaxial extrusion-based system. However, due to the inherent weak mechanical properties of alginate, the vascular conduits are not capable of biomimicking natural vascular system. In this paper, multiwall carbon nanotubes (MWCNT) were used to reinforce vascular conduits. 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 conduits both in short and long term for MWCNT reinforcement. PMID:24863208

  11. In vivo visualization of microneedle conduits in human skin using laser scanning microscopy

    International Nuclear Information System (INIS)

    Solid microneedles enhance the penetration of drugs into the viable skin but little is known about the geometry of the conduits in vivo. Therefore, laser scanning microscopy was used to visualize the conduits of a microneedle system with needles at a length of 300 ?m 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 conduits 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 conduits at the skin surface

  12. Numerical simulation of explosive volcanic eruptions from the conduit flow to global atmospheric scales

    OpenAIRE

    Textor, C.; Laboratoire des Sciences du Climat et de l' Environnement, CEA-CNRS, Gif-sur-Yvette, France; Graf, H.; Max-Planck-Institut für Meteorologie, Hamburg, Germany; Longo, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Neri, A.; Istituto Nazionale di Geofisica e Vulcanologia, Centro per la Modellistica Fisica e Pericolosita` dei Processi Vulcanici; Ongaro, T. E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Papale, P; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Timmreck, C.; Max-Planck-Institut für Meteorologie, Hamburg, Germany; Ernst, G. G. J.; Centre for Environmental and Geophysical Flows, Department of Earth Sciences, University of Bristol, U.K.

    2005-01-01

    Volcanic eruptions are unsteady multiphase phenomena, which encompass many inter-related processes across the whole range of scales from molecular and microscopic to macroscopic, synoptic and global. We provide an overview of recent advances in numerical modelling of volcanic effects, from conduit and eruption column processes to those on the Earth s climate. Conduit flow models examine ascent dynamics and multiphase processes like fragmentation, chemical reactions and mass transf...

  13. Effects of dynamically variable saturation and matrix-conduit coupling of flow in karst aquifers

    Science.gov (United States)

    Reimann, T.; Geyer, T.; Shoemaker, W.B.; Liedl, R.; Sauter, M.

    2011-01-01

    Well-developed karst aquifers consist of highly conductive conduits 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 conduit 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 conduits employing the Saint-Venant equations. Model performance tests indicate that ModBraC is able to simulate (1) unsteady and nonuniform flow in variably filled conduits, (2) draining and refilling of conduits with stable transition between free-surface and pressurized flow and correct storage representation, (3) water exchange between matrix and variably filled conduits, and (4) discharge routing through branched and intermeshed conduit 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 conduit-matrix interaction during free-surface flow. Copyright 2011 by the American Geophysical Union.

  14. Evolution of karst conduit networks in transition from pressurized flow to free-surface flow

    Science.gov (United States)

    Perne, M.; Covington, M.; Gabrovšek, F.

    2014-11-01

    Most of the existing models of speleogenesis are limited to situations where flow in all conduits is pressurized. The feedback between the distribution of hydraulic head and growth of new solution conduits determines the geometry of the resulting conduit network. We present a novel modeling approach that allows a transition from pressurized (pipe) flow to a free-surface (open-channel) flow in evolving discrete conduit networks. It calculates flow, solute transport and dissolution enlargement within each time step and steps through time until a stable flow pattern is established. The flow in each time step is calculated by calling the US Environmental Protection Agency Storm Water Management Model (US Environmental Protection Agency, 2014), which efficiently solves the 1-D Saint-Venant equations in a network of conduits. Two basic scenarios are modeled, a low-dip scenario and a high-dip scenario. In the low-dip scenario a slightly inclined plane is populated with a rectangular grid of solution conduits. The recharge is distributed to randomly selected junctions. The results for the pressurized flow regime resemble those of the existing models. When the network becomes vadose, a stable flow pathway develops along a system of conduits that occupy the lowest positions at their inlet junctions. This depends on the initial diameter and inlet position of a conduit, its total incision in a pressurized regime and its alignment relative to the dip of the plane, which plays important role during the vadose entrenchment. In the high-dip scenario a sub-vertical network with recharge on the top and outflow on the side is modeled. It is used to demonstrate the vertical development of karst due to drawdown of the water table, development of invasion vadose caves during vadose flow diversion and to demonstrate the potential importance of deeply penetrating conductive structures.

  15. Study on the air flow field of the drawing conduit in the spunbonding process

    Directory of Open Access Journals (Sweden)

    Wu Li-Li

    2015-01-01

    Full Text Available The air flow field of the drawing conduit in the spunbonding process has a great effect on the polymer drawing, the filament diameter and orientation. A numerical simulation of the process is carried out, and the results are compared with the experimental data, showing good accuracy of the numerical prediction. This research lays an important foundation for the optimal design of the drawing conduit in the spunbonding process.

  16. Poly(lactic-co-glycolic acid) conduit for repair of injured sciatic nerve: A mechanical analysis

    OpenAIRE

    Tao YU; ZHAO, CHANGFU; Li, Peng; Liu, Guangyao; Luo, Min

    2013-01-01

    Tensile stress and tensile strain directly affect the quality of nerve regeneration after bridging nerve defects by poly(lactic-co-glycolic acid) conduit 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) conduits or autogenous nerve grafts were transpl...

  17. The Himalayas: barrier and conduit for gene flow.

    Science.gov (United States)

    Gayden, Tenzin; Perez, Annabel; Persad, Patrice J; Bukhari, Areej; Chennakrishnaiah, Shilpa; Simms, Tanya; Maloney, Trisha; Rodriguez, Kristina; Herrera, Rene J

    2013-06-01

    The Himalayan mountain range is strategically located at the crossroads of the major cultural centers in Asia, the Middle East and Europe. Although previous Y-chromosome studies indicate that the Himalayas served as a natural barrier for gene flow from the south to the Tibetan plateau, this region is believed to have played an important role as a corridor for human migrations between East and West Eurasia along the ancient Silk Road. To evaluate the effects of the Himalayan mountain range in shaping the maternal lineages of populations residing on either side of the cordillera, we analyzed mitochondrial DNA variation in 344 samples from three Nepalese collections (Newar, Kathmandu and Tamang) and a general population of Tibet. Our results revealed a predominantly East Asian-specific component in Tibet and Tamang, whereas Newar and Kathmandu are both characterized by a combination of East and South Central Asian lineages. Interestingly, Newar and Kathmandu harbor several deep-rooted Indian lineages, including M2, R5, and U2, whose coalescent times from this study (U2, >40 kya) and previous reports (M2 and R5, >50 kya) suggest that Nepal was inhabited during the initial peopling of South Central Asia. Comparisons with our previous Y-chromosome data indicate sex-biased migrations in Tamang and a founder effect and/or genetic drift in Tamang and Newar. Altogether, our results confirm that while the Himalayas acted as a geographic barrier for human movement from the Indian subcontinent to the Tibetan highland, it also served as a conduit for gene flow between Central and East Asia. PMID:23580401

  18. Pressure drop characteristic in a cable-in-conduit conductor

    International Nuclear Information System (INIS)

    A cable-in-conduit conductor (CICC) is the best candidate to satisfy requirement for a superconducting magnet to be employed in a fusion machine, such as a large operating current, high magnetic field, high breakdown voltage and so on. The present drop of the conductor is a key factor in design of a cryogenic pump to be used in a magnet system in the fusion machine. Also, pressure rise at a coil quench depends on the pressure drop characteristic of the conductor. Several workers investigated the pressure drop characteristic of CICCs. Katheder attempted to derive general correlation of the pressure drop characteristic basis on the correlation used for pebble beds. He compared his correlation with the measurements for the eight different CICCs. However, there is a large error of 75% in the maximum. It seems general formula of the pressure drop characteristic of CICC has not been provided. The authors investigate the pressure drop characteristic of 30 kA, 80 m cooling path length CICCs, whose dimension is almost same as the conductor to be employed in the fusion machine. The result indicates correlation between the Reynolds number and the friction factor of CICCs obeys the conventional formula for a smooth tube, Hagen-Poesuilli formula, in laminar flow region but does not agree with the conventional formula for a smooth tube, Blasius formula, in turbulent flow region. The experimental result is compared with Katheder's correlation. Katheder's correlation does not show good agreement with the experimental result in the turbulent flow region. The correlation that the friction factor is inversely proportional to 0.157 power of the Reynolds number and the proportional constant is 0.257 coincides better with the experimental result in this region. (author)

  19. Current distribution in Cable-In-Conduit Conductors

    Energy Technology Data Exchange (ETDEWEB)

    Ferri, M.A.

    1994-05-01

    A numerical study of the current distribution in Cable-In-Conduit 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.

  20. Current distribution in Cable-In-Conduit Conductors

    International Nuclear Information System (INIS)

    A numerical study of the current distribution in Cable-In-Conduit 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

  1. Reusing the patent internal mammary artery as a conduit in redo coronary artery bypass surgery.

    Science.gov (United States)

    Nwaejike, Nnamdi; Tennyson, Charlene; Mosca, Roberto; Venkateswaran, Rajamiyer

    2016-03-01

    A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was, in patients with previous internal mammary artery/internal thoracic artery (ITA) grafts, can the internal mammary artery/ITA be reused/recycled in redo coronary artery bypass surgery? Fourteen papers were found using the reported search of which 10 represented the best evidence to answer the clinical question. There was variation in patient selection, the number of patients reported, outcome measures recorded, and methods and duration of follow-up. The results were mostly in favour of using a recycled ITA when it could be safely harvested. Most studies were retrospective. One large series of 60 patients who underwent redo coronary artery bypass grafting (CABG) using previously implanted ITAs had a mean time to reoperation of 117 ± 68 months. They reported no operative deaths; no patients required further or subsequent target vessel revascularization; 30-day mortality was 8.3% and myocardial infarction rate was 3%. Another two series of 16 and 12 patients underwent recycling of arterial grafts during coronary artery revascularization with no perioperative deaths in either. Postoperative angiography was performed in 10 patients in one of these studies, which showed excellent flow in all redone left internal thoracic artery (LITA) grafts. One study reported results from a prospective cohort of 9 patients who underwent redo coronary artery bypass grafting. Interval between operations was between 1 and 132 months. There was no perioperative mortality, but 1 patient required reintervention (to an interposition vein graft). A further study of 4 patients who underwent redo CABG using ITAs that were patent but with severe stenosis at the distal anastomosis had no mortality. Postoperative angiography showed patency of all grafts. There have also been 4 case reports on reusing the ITA/ITA in redo CABG with no damage to the reused LITA, no perioperative mortality and satisfactory follow-up at up to 29 months. Evidently, the recycled ITA can be used in redo coronary artery bypass grafting. Papers found were retrospective series or case reports. As such, there is no direct comparison in outcomes between the recycled ITA and first-time ITA harvest or any other conduit for CABG. In conclusion, we find that when it is possible to harvest a previously used ITA, studies have shown it to be a safe and viable conduit in redo CABG with good long-term outcomes. PMID:26669852

  2. Right Brachial to Atrial Xenograft Conduit for Hemodialysis Access: A Case Report.

    Science.gov (United States)

    Lu, Tony; Anaya-Ayala, Javier E; Reardon, Michael J; Peden, Eric K; Davies, Mark G

    2015-11-01

    Biologic grafts may be a viable alternative to their prosthetic counterparts in the patients who have exhausted conventional access alternatives given their superior patency rates and possible resilience to infection. This is a case report of a 66-year-old woman with end-stage renal disease and human immunodeficiency virus who has had multiple failed peripheral arteriovenous (AV) fistulas and grafts as well as inferior vena caval obstruction necessitating a transhepatic catheter for hemodialysis (HD). Given the patient's comorbidities and history, a right brachial artery-to-atrial conduit was created for long-term access. Biologic bovine carotid artery was used given its decreased susceptibility to infection and favorable patency rates. The AV access continues to function at 3.5-year follow-up and remains her primary means of HD. We present this novel use of a biologic graft as an option in patients with central venous obstruction and high risk of infection requiring exotic dialysis access. PMID:26315798

  3. A new intelligent ultrasonic flowmeter for closed conduits and open channels

    Energy Technology Data Exchange (ETDEWEB)

    Vaterlaus, H.P. [Rittmeyer Ltd., Zug (Switzerland)

    1995-12-31

    The paper describes a new intelligent ultrasonic transit time flowmeter together with typical applications in the hydro and hydropower industry. Special consideration is given to the transit time technique with intelligent signal detection allowing a resolution of flow velocity in the order of 0.8 mm/s (0.003 ft/s) with a dynamics of 4 measurements per second. Attention has been paid to safety and reliability in harsh environmental conditions and to immunity against electromagnetic disturbances. In closed conduits the sensors are designed to cover the ranges from 150 mm up to 8000 mm in pipe diameter. In open channels ranges up to 15 m in channel width can be reached. Particular emphasis is paid to velocity profile effects and straight run requirements in single or multipath performance. Due to the application of microcomputer controlled electronics, the flow rate Q is at any time corrected for the influence of parameters like Reynolds number and water temperature. The processing unit allows on site application-specific configuration. By means of front keys all system parameters can be interactively entered, modified and displayed. The unit also allows transmission of data like flow velocity, flow rate and integrated flow via a seriel interface. Hence, an uninterrupted, digital data transmission is ensured from the lowest to the highest process-control level.

  4. Solid-cryogen-stabilized, cable-in-conduit (CIC) superconducting cables

    Science.gov (United States)

    Voccio, J. P.; Michael, P. C.; Bromberg, L.; Hahn, S.

    2015-12-01

    This paper considers the use of a solid cryogen as a means to stabilize, both mechanically and thermally, magnesium diboride (MgB2) superconducting strands within a dual-channel cable-in-conduit (CIC) cable for use in AC applications, such as a generator stator winding. The cable consists of two separate channels; the outer channel contains the superconducting strands and is filled with a fluid (liquid or gas) that becomes solid at the device operating temperature. Several options for fluid will be presented, such as liquid nitrogen, hydrocarbons and other chlorofluorocarbons (CFCs) that have a range of melting temperatures and volumetric expansions (from solid at operating temperature to fixed volume at room temperature). Implications for quench protection and conductor stability, enhanced through direct contact with the solid cryogen, which has high heat capacity and thermal conductivity (compared with helium gas), will be presented. Depending on the cryogen, the conductor will be filled initially either with liquid at atmospheric conditions or a gas at high pressure (?100 atm). After cooldown, the cryogen in the stranded-channel will be solid, essentially locking the strands in place, preventing strand motion and degradation due to mechanical deformation while providing enhanced thermal capacity for stability and protection. The effect of cryogen porosity is also considered. The relatively high heat capacity of solid cryogens at these lower temperatures (compared to gaseous helium) enhances the thermal stability of the winding. During operation, coolant flow through the open inner channel will minimize pressure drop.

  5. A nerve guidance conduit with topographical and biochemical cues: potential application using human neural stem cells.

    Science.gov (United States)

    Jenkins, Phillip M; Laughter, Melissa R; Lee, David J; Lee, Young M; Freed, Curt R; Park, Daewon

    2015-12-01

    Despite major advances in the pathophysiological understanding of peripheral nerve damage, the treatment of nerve injuries still remains an unmet medical need. Nerve guidance conduits 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 conduit using a blend of polyurea and poly-caprolactone with both biochemical and topographical cues. Biochemical cues were integrated into the conduit 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 conduit with the appropriate biomimetic properties. Human neural stem cells were cultured on the conduit to evaluate its ability to promote neuronal growth and axonal extension. The nerve guidance conduit was shown to enhance cell survival, migration, and guide neurite extension. PMID:26071111

  6. Comparison of a karst groundwater model with and without discrete conduit flow

    Science.gov (United States)

    Saller, Stephen P.; Ronayne, Michael J.; Long, Andrew J.

    2013-01-01

    Karst aquifers exhibit a dual flow system characterized by interacting conduit 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 conduit 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 conduit 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 conduits. The inclusion of conduit 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 conduits, 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.

  7. In vitro evaluation of carbon-nanotube-reinforced bioprintable vascular conduits

    International Nuclear Information System (INIS)

    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 conduits directly, where conduits were reinforced with carbon nanotubes (CNTs) to enhance their mechanical properties and bioprintability. In vitro evaluation of printed conduits 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 conduits. Perfusion and permeability, cell viability, extracellular matrix formation and tissue histology were assessed and discussed, and it was concluded that CNT-reinforced vascular conduits provided a foundation for mechanically appealing constructs where CNTs could be replaced with natural protein nanofibers for further integration of these conduits in large-scale tissue fabrication. (paper)

  8. A nerve guidance conduit with topographical and biochemical cues: potential application using human neural stem cells

    Science.gov (United States)

    Jenkins, Phillip M.; Laughter, Melissa R.; Lee, David J.; Lee, Young M.; Freed, Curt R.; Park, Daewon

    2015-06-01

    Despite major advances in the pathophysiological understanding of peripheral nerve damage, the treatment of nerve injuries still remains an unmet medical need. Nerve guidance conduits 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 conduit using a blend of polyurea and poly-caprolactone with both biochemical and topographical cues. Biochemical cues were integrated into the conduit 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 conduit with the appropriate biomimetic properties. Human neural stem cells were cultured on the conduit to evaluate its ability to promote neuronal growth and axonal extension. The nerve guidance conduit was shown to enhance cell survival, migration, and guide neurite extension.

  9. Petroleum Vapor - Field Technical

    Science.gov (United States)

    The screening approach being developed by EPA OUST to evaluate petroleum vapor intrusion (PVI) requires information that has not be routinely collected in the past at vapor intrusion sites. What is the best way to collect this data? What are the relevant data quality issues and ...

  10. Use new PLGL-RGD-NGF nerve conduits for promoting peripheral nerve regeneration

    Directory of Open Access Journals (Sweden)

    Yan Qiongjiao

    2012-07-01

    Full Text Available Abstract Background Nerve conduits provide a promising strategy for peripheral nerve injury repair. However, the efficiency of nerve conduits to enhance nerve regeneration and functional recovery is often inferior to that of autografts. Nerve conduits require additional factors such as cell adhesion molecules and neurotrophic factors to provide a more conducive microenvironment for nerve regeneration. Methods In the present study, poly{(lactic acid-co-[(glycolic acid-alt-(L-lysine]} (PLGL was modified by grafting Gly-Arg-Gly-Asp-Gly (RGD peptide and nerve growth factor (NGF for fabricating new PLGL-RGD-NGF nerve conduits to promote nerve regeneration and functional recovery. PLGL-RGD-NGF nerve conduits were tested in the rat sciatic nerve transection model. Rat sciatic nerves were cut off to form a 10 mm defect and repaired with the nerve conduits. All of the 32 Wistar rats were randomly divided into 4 groups: group PLGL-RGD-NGF, group PLGL-RGD, group PLGL and group autograft. At 3 months after surgery, the regenerated rat sciatic nerve was evaluated by footprint analysis, electrophysiology, and histologic assessment. Experimental data were processed using the statistical software SPSS 10.0. Results The sciatic function index value of groups PLGL-RGD-NGF and autograft was significantly higher than those of groups PLGL-RGD and PLGL. The nerve conduction velocities of groups PLGL-RGD-NGF and autograft were significantly faster than those of groups PLGL-RGD and PLGL. The regenerated nerves of groups PLGL-RGD-NGF and autograft were more mature than those of groups PLGL-RGD and PLGL. There was no significant difference between groups PLGL-RGD-NGF and autograft. Conclusions PLGL-RGD-NGF nerve conduits are more effective in regenerating nerves than both PLGL-RGD nerve conduits and PLGL nerve conduits. The effect is as good as that of an autograft. This work established the platform for further development of the use of PLGL-RGD-NGF nerve conduits for clinical nerve repair.

  11. Evolution of karst conduit networks in transition from pressurised flow to free surface flow

    Directory of Open Access Journals (Sweden)

    M. Perne

    2014-06-01

    Full Text Available We present a novel modelling approach to study the evolution of conduit 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 conduit 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 conduits. 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 conduit, but only one conduit 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 conduits, 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 hydraulic head and give rise to high gradients and possible fast evolution of conduit systems deep within the massif.

  12. Piezoelectric trace vapor calibrator

    International Nuclear Information System (INIS)

    The design and performance of a vapor generator for calibration and testing of trace chemical sensors are described. The device utilizes piezoelectric ink-jet nozzles to dispense and vaporize precisely known amounts of analyte solutions as monodisperse droplets onto a hot ceramic surface, where the generated vapors are mixed with air before exiting the device. Injected droplets are monitored by microscope with strobed illumination, and the reproducibility of droplet volumes is optimized by adjustment of piezoelectric wave form parameters. Complete vaporization of the droplets occurs only across a 10 deg. C window within the transition boiling regime of the solvent, and the minimum and maximum rates of trace analyte that may be injected and evaporated are determined by thermodynamic principles and empirical observations of droplet formation and stability. By varying solution concentrations, droplet injection rates, air flow, and the number of active nozzles, the system is designed to deliver--on demand--continuous vapor concentrations across more than six orders of magnitude (nominally 290 fg/l to 1.05 ?g/l). Vapor pulses containing femtogram to microgram quantities of analyte may also be generated. Calibrated ranges of three explosive vapors at ng/l levels were generated by the device and directly measured by ion mobility spectrometry (IMS). These data demonstrate expected linear trends within the limited working range of the IMS detector and also exhibit subtle nonlinear behavior from the IMS measurement process

  13. Electrospun polycaprolactone/polylactic acid nanofibers as an artificial nerve conduit

    International Nuclear Information System (INIS)

    Development of conduits made of biodegradable nanofibers is gaining substantial interest due to their suitability for nerve regeneration. Among all polymeric nanofibers PCL (Poly-Caprolactone) is distinctively found for mechanical stability and PLLA (Poly (L-Lactic Acid)) for relatively faster biodegradability. The aim of this study is to investigate blending compatibility between PCL and PLLA and the ability to fabricate nanofibers conduits via electro spinning. The PCL-PLLA nano-fiber tubular made from different blend ratios of PCL-PLLA were electro spun. The electro spun nanofibers were continuously deposited over high speed rotating mandrel to fabricate nanofibers conduit having inner diameter of 2mm and the wall thickness of 55-65 m. The diameters of nano-fibers were between 715-860nm. FTIR (Fourier Transform Infrared) spectroscopy used to analyze chemical change in the blends of nerve conduits, which revealed that the PCL-PLLA blend nanofiber exhibit characteristic peaks of both PCL and PLLA and was composition dependent. The crystallinity of PCL-PLLA tubes were studied using WAXD (Wide Angle Xray Diffraction). The morphology of nanofibers were investigated under SEM (Scanning Electron Microscope). The mechanical properties of the conduits were also tested; the Young's modulus obtained for small diameter was 10MPa, twice as high as larger diameter. (author)

  14. Influence of Phreatic Conduit Floods on Matrix Storage in Unconfined Karst

    Science.gov (United States)

    Wilson, J. L.; Koski, K.

    2009-12-01

    Conduits from cm’s to m’s in effective diameter are common features in some karst aquifers, providing most of the flow capacity, but relatively little of the storage. Unconfined karst aquifers have a water table and no caprock. Phreatic conduits are completely submerged below the water table. These conditions are found, for example, in the unconfined Floridan aquifer of the United States and on the Yucatan Peninsula of Mexico. Karst conduits respond quickly to precipitation events, propagating floods that might originate with a sinking stream and eventually discharge to a spring. As the flood passes, water moves from the pressurized conduit to the surrounding rock matrix where it is stored; then, as the flood passes some of the stored flood water returns to the conduit. The amount, pattern and nature of storage is strongly influenced by the presence of an overlying water table and natural recharge. We investigate this influence using mathematical models, with implications for speleogenesis, contaminant sequestration, and aqueous geochemistry.

  15. Fabrication of patterned multi-walled poly-l-lactic acid conduits for nerve regeneration.

    Science.gov (United States)

    Li, Jianming; Shi, Riyi

    2007-09-30

    Topographical cues in the micron and nanoscale regime represent a powerful and effective method for controlling neuron and glial cell behavior. Previous studies have shown that contact guidance can facilitate axon pathfinding, accelerate neurite growth and induce glial cell alignment. In this paper, we exploit the concept of haptotaxis via implementation into three-dimensional neural based scaffolds. Polymeric poly-l-lactic acid (PLLA) conduits possessing multiple intralumenal walls and precise topography along the longitudinal axis were fabricated using solvent casting, physical imprinting and a rolling-fusing method. Measurements made on scanning electron micrographs show the conduits demonstrate a transparency factor (void to polymer ratio) of up to 87.9% and an increase in surface area of four to eight times over comparably sized hollow conduits. Intralumenal wall thickness was approximately 20 microm and physical parameters such as the number of lumens, conduit length and diameter were controllable. These results imply that the structures are conducive for cellular infiltration and proliferation. Although PLLA was used, the manufacturing techniques are highly flexible and are compatible with multiple polymer-solvent systems. Thus, the proposed conduits can be custom tailored to resorb in parallel with the healing process. Applications for these scaffolds include autograft substitutes for peripheral nerve transection or potential use in spinal cord related injuries. PMID:17644184

  16. Long Term Complications Following Heal Conduit Urinary Diversion after Radical Cystectomy

    International Nuclear Information System (INIS)

    To study the long term complications of ileal conduit urinary diversion in 36 patients with invasive urinary bladder cancer who lived more than 5 years after surgery. Patients and Methods: A retrospective study included 36 long term survivors (survival 5 years or greater) with invasive bladder cancer who did radical cystectomy or anterior pelvic excentration with ileal conduit urinary diversion at the National Cancer Institute, Cairo University before January 2004. Results: A total of 36 patients, 28 Males and 8 females, with median age at surgery of 62 years. Complications developed in 22 (61 %) patients and surgical re-intervention was needed, in 14 patients (39%). Stoma related complications developed in 7 (19%) patients, bowel related complications developed in 4 (11%), urinary tract infection and pyelonephritis was observed in 9 (25%) patients, conduit/ureteral anastomosis related complications developed in 5 (14%) patients, urolithiasis developed in 4 (11%) patients. Renal function deterioration (morphological and functional) was observed in 9 (25%) patients, nephrectomy was required in 2 patients, hemodialysis was required in 1 patient, and 1 patient had persistent hyperchloraemic acidosis. Conclusion: Long term follow-up for patients with ileal conduit urinary diversion shows high complication and high surgical re-intervention rates following this technique. Longer follow-up period for 20 or more years is needed for all urinary diversion techniques to prove either the ileal conduit will remain the gold standard for urinary diversion or other newly developed techniques will take its place

  17. Radiation response of optical fibers encased in a radiation resistant telecommunications conduit

    International Nuclear Information System (INIS)

    In this paper the results of exposing two multimode silica core optical fibers to Co-60 gamma irradiation in a radiation shielded configuration exposure consisted of dose rates at the fibers ranging from 59.6 rad(Si)/min to 92.2 rad(Si)/min within the radiation resistant conduit (RRC) and plastic conduit respectively. In was observed that the fiber within the RRC experienced approximately 8.0 dB/km less radiation induced attenuation than the fiber within the plastic conduit with identical external radiation exposure and geometries. The measurements were performed at room temperature (T = 21.5 degrees C) using well defined, highly stable optical sources and detectors

  18. Biodegradable Conduit Small Gap Tubulization for Peripheral Nerve Mutilation: A Substitute for Traditional Epineurial Neurorrhaphy

    Directory of Open Access Journals (Sweden)

    Peixun Zhang, Na Han, Tianbing Wang, Feng Xue, Yuhui Kou, Yanhua Wang, Xiaofeng Yin, Laijin Lu, Guanglei Tian, Xu Gong, Shanlin Chen, Yu Dang, Jianping Peng, Baoguo Jiang

    2013-01-01

    Full Text Available Nerve regeneration and re-innervation are usually difficult after peripheral nerve injury. Epineurium neurorrhaphy to recover the nerve continuity is the traditional choice of peripheral nerve mutilation without nerve defects, whereas the functional recovery remains quite unsatisfactory. Based on previous research in SD rats and Rhesus Monkeys, a multiple centers clinical trial about biodegradable conduit small gap tubulization for peripheral nerve mutilation to substitute traditional epineurial neurorrhaphy was carried out. Herein, the authors reviewed the literature that focused on peripheral nerve injury and possible clinical application, and confirmed the clinical possibilities of biodegradable conduit small gap tubulization to substitute traditional epineurial neurorrhaphy for peripheral nerve mutilation. The biodegradable conduit small gap tubulization to substitute traditional epineurial neurorrhaphy for peripheral nerve mutilation may be a revolutionary innovation in peripheral nerve injury and repair field.

  19. A 6-year experience with radial artery conduit for myocardial revascularization

    Directory of Open Access Journals (Sweden)

    A Sadeghpour-Tabaee

    2007-07-01

    Full Text Available Background: Excellent long-term patencies of arterial grafts are considered, superior to those of vein grafts. In this study, we present our 6 years experience in using radial artery as a conduit for myocardial revascularization. The aim of the present study was to assess the safety and early and mid term results of using radial artery in coronary artery bypass graft. Methods: The radial artery used as a conduit in 308 cases was evaluated during past 6 years, and the results obtained were processed and analyzed. Results: The operative morbidity comprised re-operation for bleeding in 3.2%, MI in 5%, with paresthesis and stitch abscess of the hand in 10% in and 3.5% respectively. Hospital mortality included 2 patients, one case being directly due to complication of harvesting radial artery.Conclusion: The results of present study were satisfactory with acceptable morbidity and mortality and favored the application of this conduit to CABG patients.

  20. Spatially resolved information on karst conduit flow from in-cave dye-tracing

    Directory of Open Access Journals (Sweden)

    U. Lauber

    2013-09-01

    Full Text Available Artificial tracers are powerful tools to investigate karst systems. Tracers are commonly injected into sinking streams or dolines, while springs serve as monitoring sites. The obtained flow and transport parameters represent mixed information from the vadose, epiphreatic and phreatic zones, i.e., the aquifer remains a black box. Accessible active caves constitute valuable but underexploited natural laboratories to gain detailed insights into the hydrologic functioning of the aquifer. Two multi-tracer tests in the catchment of a major karst spring (Blautopf, Germany with injections and monitoring in two associated water caves aimed at obtaining spatially and temporally resolved information on groundwater flow in different compartments of the system. Two tracers were injected in the caves to characterize the hydraulic connections between them and with the spring. Two injections at the land surface, far from the spring, aimed at resolving the aquifer's internal drainage structure. Tracer breakthrough curves were monitored by field fluorimeters in caves and at the spring. Results demonstrate the dendritic drainage structure of the aquifer. It was possible to obtain relevant flow and transport parameters for different sections of this system. The highest mean flow velocities (275 m h?1 were observed in the near-spring epiphreatic section (open-channel flow, while velocities in the phreatic zone (pressurized flow were one order of magnitude lower. Determined conduit water volumes confirm results of water balances and hydrograph analyses. In conclusion, experiments and monitoring in caves can deliver spatially resolved information on karst aquifer heterogeneity and dynamics that cannot be obtained by traditional investigative methods.

  1. Pressure distribution along the AGS vacuum chambers with new types of pump out conduits

    Energy Technology Data Exchange (ETDEWEB)

    Nayak, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Mapes, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Smart, L. [Brookhaven National Lab. (BNL), Upton, NY (United States); Weiss, D. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-10-28

    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 conduits, and similar analysis using FEM in ANSYS is presented in this paper with the newer type of pump out conduit.

  2. Havery Mudd 2014-2015 Computer Science Conduit Clinic Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Aspesi, G [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bai, J [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Deese, R [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Shin, L [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-05-12

    Conduit, 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 Conduit 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.

  3. Pressure distribution along the AGS vacuum chambers with new types of pump out conduits

    International Nuclear Information System (INIS)

    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 conduits, and similar analysis using FEM in ANSYS is presented in this paper with the newer type of pump out conduit.

  4. Chitosan conduits combined with nerve growth factor microspheres repair facial nerve defects

    OpenAIRE

    Liu, HuaWei; Wen, Weisheng; HU, MIN; Bi, Wenting; CHEN, LIJIE; Liu, Sanxia; Chen, Peng; Tan, Xinying

    2013-01-01

    Microspheres containing nerve growth factor for sustained release were prepared by a compound method, and implanted into chitosan conduits to repair 10-mm defects on the right buccal branches of the facial nerve in rabbits. In addition, chitosan conduits combined with nerve growth factor or normal saline, as well as autologous nerve, were used as controls. At 90 days post-surgery, the muscular atrophy on the right upper lip was more evident in the nerve growth factor and normal sa-line groups...

  5. Biological conduits combining bone marrow mesenchymal stem cells and extracellular matrix to treat long-segment sciatic nerve defects

    Directory of Open Access Journals (Sweden)

    Yang Wang

    2015-01-01

    Full Text Available The transplantation of polylactic glycolic acid conduits 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 conduit + bone marrow mesenchymal stem cells, or a polylactic glycolic acid conduit + 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 conduit + bone marrow mesenchymal stem cells + extracellular matrix gel group, followed by the polylactic glycolic acid conduit + bone marrow mesenchymal stem cells group, and then the autologous nerve group. Hematoxylin-eosin staining demonstrated that compared with the polylactic glycolic acid conduit + 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 conduit, in the polylactic glycolic acid conduit + bone marrow mesenchymal stem cells + extracellular matrix gel group. These results indicate that bridging 10-mm sciatic nerve defects with a polylactic glycolic acid conduit + 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 found with the polylactic glycolic acid conduit + bone marrow mesenchymal stem cells + extracellular matrix gel grafts than with the polylactic glycolic acid conduit + bone marrow mesenchymal stem cells grafts and the autologous nerve grafts.

  6. Ecoulements intermittents de gaz et de liquide en conduite verticale Intermittent Gas and Liquid Flows in a Vertical Pipe.

    Directory of Open Access Journals (Sweden)

    Line A.

    2006-11-01

    Full Text Available Le modèle présenté ici permet la pré-détermination du gradient de pression, du taux global de gaz, et de grandeurs caractéristiques de l'intermittence, dans un écoulement à poches et bouchons en conduite verticale. L'écriture des lois de conservation en moyenne phasique conditionnelle conduit à la définition d'une cellule moyenne équivalente. La fermeture du modèle est assurée par des lois de contrainte de cisaillement film-paroi, film-poche, bouchon-paroi, par une loi d'arrachage du gaz au culot de la poche, une loi de glissement du gaz dans les bouchons et par une loi de la vitesse moyenne de propagation des fronts de poches. Le calibrage et la qualification du modèle s'appuient sur deux banques de données, dont l'une a été obtenue avec des fluides pétroliers dans des conditions proches des situations industrielles (boucle diphasique de Boussens. The model described here can be used to predetermine the pressure gradient, the overall gas rate and the characteristic intermittence magnitudes in pocket and slug flow in a vertical pipe. The way governing equations in the conditional phase average are written defines an equivalent average cell. The model is closed by film/wall, film/pocket and slug/wall shear-stress laws, by a pulloff law for the gas at the bottom of the pocket, a slippage law for the gas in the slugs, and a mean propagation velocity law for the pocket fronts. The calibration and qualification of the model are based on two data banks, one of which contains data on petroleum fluids under conditions close to industrial situations (two-phase loop at Boussens.

  7. Reconstrução arterial com tubo de pericárdio bovino corrugado Arterial reconstruction with crimped bovine pericardial conduit

    Directory of Open Access Journals (Sweden)

    Cláudio A Salles

    1992-06-01

    Full Text Available No período de agosto de 1989 a fevereiro de 1992, 32 pacientes foram submetidos a reconstruções vasculares utilizando-se condutos de pericárdio bovino corrugado preservado em glutaraldeído. A incorporação do principio crimping utilizado nas próteses vasculares sintéticas proporcionou tubos que mantêm sua forma cilíndrica, mesmo quando submetidos a curvaturas. Vinte e nove pacientes (Grupo I eram portadores de doenças da aorta torácica e/ou abdominal, incluindo aneurismas, dissecções agudas, coarctação da aorta e lesão oclusiva aorto-ilíaca. A reconstrução da aorta torácica foi realizada em 25 pacientes (incluindo a substituição da valva aórtica em 10, da aorta abdominal em 2 e aorto-ilíaca em 2. Três pacientes (Grupo II, portadores de cardiopatias congênitas complexas, foram submetidos a reconstrução da via de saída do ventrículo direito em 2 e a operação de Fontan em 1. A mortalidade hospitalar no Grupo I foi 24% (7 pacientes, causada por baixo débito cardíaco em 4, recidiva precoce da dissecção em dois e infecção respiratória em 1. Seis destes óbitos ocorreram em pacientes operados na fase aguda de dissecção aórtica. Não houve nenhum óbito no Grupo II. Houve um óbito tardio no Grupo I devido a complicações metabólicas relacionadas a diabetes e insuficiência renal crônica. Esta experiência clínica inicial registrou um seguimento médico de 16 meses por paciente, com um máximo de 32 meses e não se verificou nenhuma complicação tardia relacionada ao conduto de pericárdio bovino corrugado.From August 1989 to February 1992, 32 patients underwent vascular reconstructions using crimped bovine pericardial conduits processed in glutaraldehyde. The introduction of the crimping process used for synthetic vascular prosthesis provided circular tubes, which retain their shape with bending and avoid kinking. Twenty-nine patients (Group I presented vascular lesions involving the thoracic and/or abdominal aorta, including aneurysms, acute dissections, coarctation and aorto-iliac lesion. The thoracic aortic reconstruction was performed in 25 patients, including aortic valve replacement in 10, the abdominal aorta in 2, and the aortic bifurcation in 2. Three patients (Group II with complex congenital heart lesions underwent reconstruction of the right ventricular outflow tract in 2, and the Fontan operation in 1. Hospital mortality in Group I was 24% (7 patients. Causes of death were low cardiac output in 4, recurrence of aortic dissection in 2 and respiratory infection in 1. Six of them had been operated upon as emergencies due to acute aortic dissection. All patients in group II survived the operation. There was 1 late death in group I due to methabolic complications related to diabetes and chronic renal failure. This initial clinical experience showed a mean follow-up of 16 months per patient and the longest follow-up was 32 months. It was not observed any late complication related to the crimped bovine pericardial conduit up-to-date.

  8. Reconstrução arterial com tubo de pericárdio bovino corrugado / Arterial reconstruction with crimped bovine pericardial conduit

    Scientific Electronic Library Online (English)

    Cláudio A, Salles; Nilzo A. M, Ribeiro; Renato A. K, Kalil; Gilberto Lino, Vieira; Liberato S. S, Souza; Paulo M, Borém; Miguel E. C, Andrade; Rogério D, Faleiros; Marcos A. M, Andrade Jr.

    1992-06-01

    Full Text Available No período de agosto de 1989 a fevereiro de 1992, 32 pacientes foram submetidos a reconstruções vasculares utilizando-se condutos de pericárdio bovino corrugado preservado em glutaraldeído. A incorporação do principio crimping utilizado nas próteses vasculares sintéticas proporcionou tubos que mantê [...] m sua forma cilíndrica, mesmo quando submetidos a curvaturas. Vinte e nove pacientes (Grupo I) eram portadores de doenças da aorta torácica e/ou abdominal, incluindo aneurismas, dissecções agudas, coarctação da aorta e lesão oclusiva aorto-ilíaca. A reconstrução da aorta torácica foi realizada em 25 pacientes (incluindo a substituição da valva aórtica em 10), da aorta abdominal em 2 e aorto-ilíaca em 2. Três pacientes (Grupo II), portadores de cardiopatias congênitas complexas, foram submetidos a reconstrução da via de saída do ventrículo direito em 2 e a operação de Fontan em 1. A mortalidade hospitalar no Grupo I foi 24% (7 pacientes), causada por baixo débito cardíaco em 4, recidiva precoce da dissecção em dois e infecção respiratória em 1. Seis destes óbitos ocorreram em pacientes operados na fase aguda de dissecção aórtica. Não houve nenhum óbito no Grupo II. Houve um óbito tardio no Grupo I devido a complicações metabólicas relacionadas a diabetes e insuficiência renal crônica. Esta experiência clínica inicial registrou um seguimento médico de 16 meses por paciente, com um máximo de 32 meses e não se verificou nenhuma complicação tardia relacionada ao conduto de pericárdio bovino corrugado. Abstract in english From August 1989 to February 1992, 32 patients underwent vascular reconstructions using crimped bovine pericardial conduits processed in glutaraldehyde. The introduction of the crimping process used for synthetic vascular prosthesis provided circular tubes, which retain their shape with bending and [...] avoid kinking. Twenty-nine patients (Group I) presented vascular lesions involving the thoracic and/or abdominal aorta, including aneurysms, acute dissections, coarctation and aorto-iliac lesion. The thoracic aortic reconstruction was performed in 25 patients, including aortic valve replacement in 10, the abdominal aorta in 2, and the aortic bifurcation in 2. Three patients (Group II) with complex congenital heart lesions underwent reconstruction of the right ventricular outflow tract in 2, and the Fontan operation in 1. Hospital mortality in Group I was 24% (7 patients). Causes of death were low cardiac output in 4, recurrence of aortic dissection in 2 and respiratory infection in 1. Six of them had been operated upon as emergencies due to acute aortic dissection. All patients in group II survived the operation. There was 1 late death in group I due to methabolic complications related to diabetes and chronic renal failure. This initial clinical experience showed a mean follow-up of 16 months per patient and the longest follow-up was 32 months. It was not observed any late complication related to the crimped bovine pericardial conduit up-to-date.

  9. Vapor pressures and enthalpies of vaporization of azides

    Energy Technology Data Exchange (ETDEWEB)

    Verevkin, Sergey P., E-mail: sergey.verevkin@uni-rostock.de [Department of Physical Chemistry, University of Rostock, Dr-Lorenz-Weg 1, D-18059 Rostock (Germany); Emel' yanenko, Vladimir N. [Department of Physical Chemistry, University of Rostock, Dr-Lorenz-Weg 1, D-18059 Rostock (Germany); Algarra, Manuel [Centro de Geologia do Porto, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Manuel Lopez-Romero, J. [Department of Organic Chemistry, University of Malaga. Campus de Teatinos s/n, 29071 Malaga (Spain); Aguiar, Fabio; Enrique Rodriguez-Borges, J.; Esteves da Silva, Joaquim C.G. [Centro de Investigacao em Quimica (CIQ-UP), Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal)

    2011-11-15

    Highlights: > We prepared and measured vapor pressures and vaporization enthalpies of 7 azides. > We examined consistency of new and available in the literature data. > Data for geminal azides and azido-alkanes selected for thermochemical calculations. - Abstract: Vapor pressures of some azides have been determined by the transpiration method. The molar enthalpies of vaporization {Delta}{sub l}{sup g}H{sub m} of these compounds were derived from the temperature dependencies of vapor pressures. The measured data sets were successfully checked for internal consistency by comparison with vaporization enthalpies of similarly structured compounds.

  10. US Food and Drug Administration /Conformit Europe- approved absorbable nerve conduits for clinical repair of peripheral and cranial nerves.

    Science.gov (United States)

    Meek, M F; Coert, J H

    2008-04-01

    Several absorbable nerve conduits are approved by the US Food and Drug Administration (FDA) and Conformit Europe (CE) for clinical repair of peripheral and cranial nerves . Surgeons are often not aware of the different(bio) materials of these conduits when performing nerve repair. An overview of these FDA- and CE-approved absorbable nerve conduits for clinical use is presented . PubMed, MEDLINE, and the companies selling the conduits were consulted . The available FDA and CE absorbable nerve conduits for peripheral and cranial nerve repair are 2 collagen- and 2 synthetic- polyester based conduits. The available clinical data, the price, the length, and the composition of the tube show significant differences. Based on the available data in this paper at this moment, we favor the PGA (Neurotube) nerve conduit for repair of peripheral and cranial nerve defects because of its advantages in length, price, and availability of clinical data. However, no prospective studies comparing the available nerve conduits have been published. PMID:18437784

  11. A novel balloon assisted two-stents telescoping technique for repositioning an embolized stent in the pulmonary conduit.

    Science.gov (United States)

    Kobayashi, Daisuke; Gowda, Srinath T; Forbes, Thomas J

    2014-08-01

    A 9-year-old male, with history of pulmonary atresia and ventricular septal defect, status post complete repair with a 16 mm pulmonary homograft in the right ventricular outflow tract (RVOT) underwent 3110 Palmaz stent placement for conduit stenosis. Following deployment the stent embolized proximally into the right ventricle (RV). We undertook the choice of repositioning the embolized stent into the conduit with a transcatheter approach. Using a second venous access, the embolized stent was carefully maneuvered into the proximal part of conduit with an inflated Tyshak balloon catheter. A second Palmaz 4010 stent was deployed in the distal conduit telescoping through the embolized stent. The Tyshak balloon catheter was kept inflated in the RV to stabilize the embolized stent in the proximal conduit until it was successfully latched up against the conduit with the deployment of the overlapping second stent. One year later, he underwent Melody valve implantation in the pre-stented conduit relieving conduit insufficiency. This novel balloon assisted two-stents telescoping technique is a feasible transcatheter option to secure an embolized stent from the RV to the RVOT. PMID:24402732

  12. 78 FR 63176 - Notice of Preliminary Determination of a Qualifying Conduit Hydropower Facility and Soliciting...

    Science.gov (United States)

    2013-10-23

    ... Energy Regulatory Commission Notice of Preliminary Determination of a Qualifying Conduit Hydropower... 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 22 kW Orchard City Water Treatment...

  13. Percutaneous transthoracic computed tomography-guided AICD insertion in a patient with extracardiac Fontan conduit.

    LENUS (Irish Health Repository)

    Murphy, Darra T

    2011-02-01

    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 conduit who had presented with two out-of-hospital cardiac arrests. The procedure avoided the need for lead placement at thoracotomy.

  14. Development of high strength austenitic stainless steel for conduit of Nb3Al conductor

    International Nuclear Information System (INIS)

    Japan Atomic Energy Research Institute (JAERI) started developing new austenitic stainless steel for a conduit (1 - 2 mm) of a Nb3Al conductor in collaboration with Nippon Steel Corporation (NSC). A high strength austenitic stainless steel is required for a conduit of a Nb3Al conductor to make the best use of superconducting properties of a Nb3Al conductor. JAERI and NSC successfully developed the high strength austenitic stainless steel, JN1 (YS ? 1,300 MPa, KIc ? 200 MPa?m at 4K) for magnet structures having thick section. However, JN1 is not suitable for a conduit material because elongation of JN1 decreases to less than 10 % due to sensitization during reaction heat treatment for Nb3Al. Therefore, modification of JN1 was performed as a first step to develop a new conduit material which withstands Nb3Al reaction heating. Small trial lots heat-treated at 973 - 1173 K for 2 - 200 hours were prepared and evaluated by Charpy impact test and tensile test at 77 K and 4K. A material having yield strength of 1,390 MPa and elongation of 34 % after aging at 973 K x 200 h are developed up to now. This paper describes requirements on the mechanical properties and status of the development work. In addition, empirical equations to predict 4K yield strength, elongation, and Charpy absorbed energy from 77K data are proposed in this paper

  15. Percutaneous Transthoracic Computed Tomography-Guided AICD Insertion in a Patient with Extracardiac Fontan Conduit

    International Nuclear Information System (INIS)

    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 conduit who had presented with two out-of-hospital cardiac arrests. The procedure avoided the need for lead placement at thoracotomy.

  16. Support and positioning conduit for measuring instruments in a nuclear reactor core

    International Nuclear Information System (INIS)

    The external tubular casing of the measure conduit has many tubular sections machined to receive probes. These tubular sections are connected by flexible sections. An open final flexible section with apertures in its lateral wall put the casing in equipression with the primary water

  17. A Simplified 1-D Model for Calculating CO2 Leakage through Conduits

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y.; Oldenburg, C.M.

    2011-02-15

    In geological CO{sub 2} storage projects, a cap rock is generally needed to prevent CO{sub 2} from leaking out of the storage formation. However, the injected CO{sub 2} may still encounter some discrete flow paths such as a conductive well or fault (here referred to as conduits) through the cap rock allowing escape of CO{sub 2} from the storage formation. As CO{sub 2} migrates upward, it may migrate into the surrounding formations. The amount of mass that is lost to the formation is called attenuation. This report describes a simplified model to calculate the CO{sub 2} mass flux at different locations of the conduit and the amount of attenuation to the surrounding formations. From the comparison among the three model results, we can conclude that the steady-state conduit model (SSCM) provides a more accurate solution than the PMC at a given discretization. When there is not a large difference between the permeability of the surrounding formation and the permeability of the conduits, and there is leak-off at the bottom formation (the formation immediately above the CO{sub 2} plume), a fine discretization is needed for an accurate solution. Based on this comparison, we propose to use the SSCM in the rapid prototype for now given it does not produce spurious oscillations, and is already in FORTRAN and therefore can be easily made into a dll for use in GoldSim.

  18. Transient and asymptotic dispersion in confined sphere packings with cylindrical and non-cylindrical conduit geometries.

    Science.gov (United States)

    Khirevich, Siarhei; Höltzel, Alexandra; Tallarek, Ulrich

    2011-06-28

    We study the time and length scales of hydrodynamic dispersion in confined monodisperse sphere packings as a function of the conduit geometry. By a modified Jodrey-Tory algorithm, we generated packings at a bed porosity (interstitial void fraction) of ?=0.40 in conduits with circular, rectangular, or semicircular cross section of area 100?d(p)(2) (where d(p) is the sphere diameter) and dimensions of about 20d(p) (cylinder diameter) by 6553.6d(p) (length), 25d(p) by 12.5d(p) (rectangle sides) by 8192d(p) or 14.1d(p) (radius of semicircle) by 8192d(p), respectively. The fluid-flow velocity field in the generated packings was calculated by the lattice Boltzmann method for Péclet numbers of up to 500, and convective-diffusive mass transport of 4×10(6) inert tracers was modelled with a random-walk particle-tracking technique. We present lateral porosity and velocity distributions for all packings and monitor the time evolution of longitudinal dispersion up to the asymptotic (long-time) limit. The characteristic length scales for asymptotic behaviour are explained from the symmetry of each conduit's velocity field. Finally, we quantify the influence of the confinement and of a specific conduit geometry on the velocity dependence of the asymptotic dispersion coefficients. PMID:21576163

  19. Vapor pumps and gas-driven machines

    International Nuclear Information System (INIS)

    The vapor pump, patented in 1979 by Gaz de France, is an additional mass and heat exchanger which uses the combustion air of fuel-burning machines as an additional cold source. This cold source is preheated and, above all, humidified before reaching the burner, by means of the residual sensible and latent heat in the combustion products of the fuel-burning process. This final exchanger thus makes it possible, in many cases, to recover all the gross calorific value of natural gas, even when the combustion products leave the process at a wet temperature greater than 600 C, the maximum dew point of the products of normal combustion. Another significant advantage of the vapor pump being worth highlighting is the selective recycling of water vapor by the vapor pump which reduces the adiabatic combustion temperature and the oxygen concentration in the combustion air, two factors which lead to considerable reductions in nitrogen oxides formation, hence limiting atmospheric pollution. Alongside a wide range of configurations which make advantageous use of the vapor pump in association with gas-driven machines and processes, including gas turbines, a number of boiler plant installations are also presented

  20. Numerical investigation of temporal changes in volcanic deformation caused by a gas slug ascent in the conduit

    Science.gov (United States)

    Kawaguchi, Ryohei; Nishimura, Takeshi

    2015-09-01

    Strombolian type eruptions are considered to be generated by a sudden release of a large gas slug that migrates upward in the conduit 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 conduit by using a gas slug ascent model presented by James et al. (2008). As a gas slug ascends in the conduit, its volume expands because of depressurization. Hence, the magma head lifts up in the conduit and the upper part of the conduit wall is stressed. In the conduit, 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 conduit. 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 conduit. As the gas slug reaches the shallow part of conduit, 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 conduit 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.

  1. Fabrication of Off-the-Shelf Multilumen Poly(Ethylene Glycol) Nerve Guidance Conduits Using Stereolithography.

    Science.gov (United States)

    Arcaute, Karina; Mann, Brenda K; Wicker, Ryan B

    2011-01-01

    A manufacturing process for fabricating off-the-shelf multilumen poly(ethylene glycol) (PEG)-based nerve guidance conduits (NGCs) was developed that included the use of stereolithography (SL). A rapid fabrication strategy for complex 3D scaffolds incorporated postprocessing with lyophilization and sterilization to preserve the scaffold, creating an implantable product with improved suturability. SL is easily adaptable to changes in scaffold design, is compatible with various materials and cells, and can be expanded for mass manufacture. The fabricated conduits were characterized using optical and scanning electron microscopy, and measurements of swelling ratio, dimensional swelling factor, resistance to compression, and coefficient of friction were performed. Water absorption curves showed that the conduits after lyophilization and sterilization return easily and rapidly to a swollen state when placed in an aqueous solution, successfully maintaining their original overall structure as required for implantation. Postprocessed conduits at the swollen state were less slippery and therefore easier to handle than those without postprocessing. Suture pullout experiments showed that NGCs fabricated with a higher concentration of PEG were better able to resist suture pullout. NGCs having a multilumen design demonstrated a better resistance to compression than a single-lumen design with an equivalent surface area, as well as a greater force required to collapse the design. Conduits fabricated with a higher PEG concentration were shown to have compressive resistances comparable to those of commercially available NGCs. The use of SL with PEG and the manufacturing process developed here shows promise for improving the current state of the art in peripheral nerve repair strategies. PMID:20673135

  2. Flowmeter for determining average rate of flow of liquid in a conduit

    Science.gov (United States)

    Kennerly, John M. (Knoxville, TN); Lindner, Gordon M. (Oak Ridge, TN); Rowe, John C. (Oak Ridge, TN)

    1982-01-01

    This invention is a compact, precise, and relatively simple device for use in determining the average rate of flow of a liquid through a conduit. 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 conduit 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 conduit and is sized to operate at a lower pressure than the conduit, 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 conduit can be determined from the above-mentioned time and the vessel volume filled by the liquid during that time.

  3. Muonium formation in vapors

    International Nuclear Information System (INIS)

    The fractions of positive muons thermalizing in vapors as either the muonium atom (fsub(M)) or in diamagnetic environments (fsub(D)) have been measured in water, methanol, hexane, c-hexane, the chlorinated methanes and in TMS, in the pressure range from approximately 0.1 to approximately 2.5 atm. There is a marked difference in every case in comparison with the corresponding fractions (Psub(M),Psub(D)) measured in condensed media, with approximately 80 percent of incident muons forming muonium in the vapor phase compared to approximately 20 percent in the corresponding condensed phases. CClsub(4) appears somewhat anomalous in that it shows an unusually small muonium fraction in the vapor (fsub(D) approximately fsub(M)=0.5) and an unusually large diamagnetic fraction in the liquid (Psub(D)=1.0); these results can be attributed to large hot atom cross sections extending to the thermal regime, manifest as a relatively fast thermal rate constant for Mu + CClsub(4) (ksub(MU)=(2.9+-0.8) x 10sup(8) Msup(-1) ssup(-1)). The vapor phase results can be understood in terms of a charge exchange/hot atom (ion) model, providing also a likely explanation for observed pressure dependent fsub(D)'s in hexane, c-hexane and TMS at low (<0.5 atm) pressures in terms of termolecular processes, in analogy with some hot tritium studies. In the condensed phase, however, the present vapor phase results indicate that hot atom reactions cannot account for more than about 30 percent of the much larger diamagnetic fractions seen, strongly suggesting therefore that radiation induced spur effects play a dominant role in determining thermal muon fractions in condensed media

  4. Speleogenetic effects of interaction between deeply derived fracture-conduit flow and intrastratal matrix flow in hypogene karst settings

    Directory of Open Access Journals (Sweden)

    Tymokhina Elizaveta

    2012-07-01

    Full Text Available In carbonate rocks, especially in those with high primary porosity such as most Cenozoic carbonates, the interaction between deeply derived rising flow through sub-vertical fracture-controlled conduits and intrastratal matrix flow of shallower systems can invoke mixing cor- rosion and result in prominent speleogenetic effects. This paper outlines a conceptual model of such interaction and provides instructive field examples of relevant morphological effects from two different regions within the Prichernomorsky (north Black Sea basin, where karst features are developed in lower Pliocene, Eocene and Paleocene limestones. In the Crimean fore-mountain region, extensive steep to ver- tical limestone scarps formed through recent exposure of hypogenic fracture-controlled conduits provide outstanding possibilities to directly examine details of the original karstic porosity. The morphological effects of the conduit/matrix interaction, documented in both caves and exposed scarps, include lateral widening of sub-vertical conduits within the interaction intervals (formation of lateral notches and niches and the development of side bedding-parallel conduits, pockets and vuggy-spongework zones. Natural convection circulation, invoked by interaction of the two flow systems, spreads the morphological effects throughout the conduit space above the interaction interval. Where the interaction of the two flow systems is particularly strongly localized, such as along junctions of two vertical fracture sets, the resultant morphological effect can take the form of isolated chambers. The variety of speleogenetic features developed through the conduit/matrix interaction, can be broadly grouped into two categories: 1 variously shaped swells of the major fracture conduit itself (morphological fea- tures of its walls – niches and pockets, and 2 features of the vuggy-spongework halo surrounding the conduit. This halo includes clustered and stratiform cavities, spongework zones and lateral side conduits. The speleogenetic features due to conduit/matrix flow interaction, especially the halo forms, often demonstrate distinct asymmetry between opposite walls of the conduits. The prominent phenomenon of the vuggy-spongework halo around fracture-controlled conduits has important hydrogeological implications. A comparison of karst features in different regions and rock formations clearly shows that in spite of some distinctions imposed by local structural, sedimentological and paleo-hydrogeological peculiarities, hypogenic speleoforms in limestones of different age and of different degree of diagenetic maturity demonstrate remarkable similarities.

  5. Double Meanings.

    Science.gov (United States)

    Davis, Jonathan; Davis, Lisa

    2001-01-01

    Discusses the use of double meanings and figurative language or figures of speech in literature and how confusing it can be for beginning readers. Describes class activities that can help students construct, examine, and extend the meaning of what they read and includes a worksheet, evaluation suggestions, and extension activities. (LRW)

  6. 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

    Science.gov (United States)

    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.

  7. Challenges of using electrical resistivity method to locate karst conduits-A field case in the Inner Bluegrass Region, Kentucky

    Science.gov (United States)

    Zhu, J.; Currens, J.C.; Dinger, J.S.

    2011-01-01

    Conduits 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. Conduits 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 conduits. This study used electrical resistivity method to search for an unmapped karst conduit 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 conduits. Drilling near an anomaly identified by an electrical resistivity profile resulted in successful penetration of a major water-filled conduit. 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 conduit and other water-bearing features such as water-filled fracture zones were undistinguishable. The electrical resistivity method is useful in conduit 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 conduit. ?? 2011 Elsevier B.V.

  8. Constraints on the Geometries and Compositions of Subvolcanic Conduits from Intrusions of the San Rafael Swell, Utah

    Science.gov (United States)

    Wetmore, P. H.; Connor, C.; Wilson, J.

    2010-12-01

    Conduit models incorporate varying degrees of complexity (or parsimony) and account for the transport properties of magmas, steady-state or transient behavior, and conduit geometry (e.g., 1- to 1.5 D, variable width and erodable conduit walls). Improvement of these models is important if we are to work toward deployment of eruption models at active volcanoes, link these models to geophysical observations (seismic, deformation, gravity) and eventually forecast eruption magnitude. One conclusion of a recent comparison of many conduit models (Sahagian, 2005 JVGR) is that next generation models need to better account for interaction of the erupting mixture with surrounding wall rocks (accounting for melting, solidification, and erosion) and better account for the effects of conduit shape on flows. In an effort to address these issues our research group has completed mapping of a suite of subvolcanic intrusions (dikes, sills, and conduits) from the west-central San Rafael Swell of central Utah. The results of this study demonstrate that vertical flow of melt through crust in this system of intrusion was dominated by dikes. Conduits form, in nearly all cases, as a result of localized flow along dikes. The conduits are commonly comprised of three distinct lithologic units: brecciated host rock (without any intrusive material), brecciated host rock mixed with brecciated and mechanically contaminated intrusive, and relatively clean (i.e. containing less than ~10% accidental material) intrusive. Contacts between all three of these units are typically discreet and traceable for several tens of meters. In some examples clasts within the unmixed breccia unit exhibit a strong alignment of clasts dipping into the core of the conduit. These observations suggests an evolutionary history that involves an early phase of brecciation and mixing, followed by confined flow with a fluidized mixed unit and an essentially uninvolved outer zone (i.e. the breccia). The final phase likely involves the inward collapse as fluid pressures reduce.

  9. Design criteria for stability in cable-in-conduit conductors

    International Nuclear Information System (INIS)

    Stability is a key point in the design of large conductors for application in fusion machines such as NETY or ITER. In the electromagnetically noisy environment characterizing the surroundings of a plasma, the superconductor should be stable against all expected heat deposition, including a.c. losses driven by plasma disruptions. Since all sources of thermal perturbations cannot be adequately identified, predicted or calculated, the design must allow for suitable margins. To ensure this, stability must be considered as a design criterion which is checked by means of analytical and numerical methods and later calibrated against experimental measurements of transient heat transfer and stability behaviour. In this paper the procedure developed at NET is described for the design and analysis of the stability margin of conductors for the toroidal and poloidal field coils. These methods are applied to the generation of stability curves and maps which are used to set operating limits for the 40 kA NET conductor. The design criteria and analytical methods can be appropriately modified for other conductors and coil applications. (author)

  10. Robot-Assisted Laparoscopic Partial Colpectomy and Intracorporeal Ileal Conduit Urinary Diversion (Bricker) for Cervical Adenocarcinoma Recurrence

    Science.gov (United States)

    Uzan, Jennifer; Cornou, Caroline; Bensaid, Chérazade; Audenet, François; Ngô, Charlotte; Bats, Anne-Sophie; Lecuru, Fabrice

    2015-01-01

    Ileal conduit urinary diversion (Bricker) is a standard surgical open procedure. The Da Vinci robot allowed precision for this surgical procedure, especially for intracorporeal suturing. Meanwhile, few reports of robot-assisted laparoscopic ileal conduit diversion (Bricker) are described in the literature. We report the case of a 69-year-old patient with a vaginal recurrence of cervical adenocarcinoma associated with vesicovaginal fistula treated by robot-assisted laparoscopic partial colpectomy and ileal conduit urinary diversion (Bricker). The robot-assisted laparoscopic procedure followed all surgical steps of the open procedure. Postoperative period was free of complications. PMID:26634161

  11. Data in support of in vivo studies of silk based gold nano-composite conduits for functional peripheral nerve regeneration.

    Science.gov (United States)

    Das, Suradip; Sharma, Manav; Saharia, Dhiren; Sarma, Kushal Konwar; Sarma, Monalisa Goswami; Borthakur, Bibhuti Bhusan; Bora, Utpal

    2015-09-01

    In the present data article we report the in vitro and in vivo biocompatibility of fabricated nerve conduits described in Das et al. [1]. Green synthesised gold nanoparticles (GNPs) were evaluated for their cytotoxicity in rat Schwann cells (SCTM41). We also describe herein the adhesion and proliferation of Schwann cells over the nanofibrous scaffolds. Methods describing surgical implantation of conduits in a rat sciatic nerve injury model, confirming its accurate implantation as well as the porosity and swelling tendency of the nerve conduits are illustrated in the various figures and graphs. PMID:26217808

  12. Data in support of in vivo studies of silk based gold nano-composite conduits for functional peripheral nerve regeneration

    Directory of Open Access Journals (Sweden)

    Suradip Das

    2015-09-01

    Full Text Available In the present data article we report the in vitro and in vivo biocompatibility of fabricated nerve conduits described in Das et al. [1]. Green synthesised gold nanoparticles (GNPs were evaluated for their cytotoxicity in rat Schwann cells (SCTM41. We also describe herein the adhesion and proliferation of Schwann cells over the nanofibrous scaffolds. Methods describing surgical implantation of conduits in a rat sciatic nerve injury model, confirming its accurate implantation as well as the porosity and swelling tendency of the nerve conduits are illustrated in the various figures and graphs.

  13. Enceladus' water vapor plume.

    Science.gov (United States)

    Hansen, Candice J; Esposito, L; Stewart, A I F; Colwell, J; Hendrix, A; Pryor, W; Shemansky, D; West, R

    2006-03-10

    The Cassini spacecraft flew close to Saturn's small moon Enceladus three times in 2005. Cassini's UltraViolet Imaging Spectrograph observed stellar occultations on two flybys and confirmed the existence, composition, and regionally confined nature of a water vapor plume in the south polar region of Enceladus. This plume provides an adequate amount of water to resupply losses from Saturn's E ring and to be the dominant source of the neutral OH and atomic oxygen that fill the Saturnian system. PMID:16527971

  14. Gasoline vapor biofiltration

    Energy Technology Data Exchange (ETDEWEB)

    Paca, J.; Halecky, M. [Institute of Chemical Technology, Department of Fermentation Chemistry and Bioengineering, Prague (Czech Republic); Maryska, M. [Institute of Chemical Technology, Department of Glass and Ceramics, Prague (Czech Republic); Jones, K. [South Texas Environmental Institute, Texas A and M University-Kingsville, Kingsville (United States)

    2007-10-15

    While gasoline vapor emissions are common sources of air pollution, very few results have been published on the biofilter biodegradation of gasoline vapors in flowing waste gases. This investigation reports on a bench-scale biofilter of an ID of 50 mm and a bed height of 850 mm with an inexpensive fire clay chip medium as a packing material. The biofilter was inoculated with a concentrate of a mixed culture of the common microflora. After an acclimatization period of three weeks, loading tests were carried out at increasing gasoline inlet concentrations at a constant Empty Bed Retention Time (EBRT) of 16 min. Evaluating the removal rate and efficiency of aliphatic and aromatic fractions of the gasoline vapor, it was found that in a range of overall organic loading (OL{sub TPH}) up to 33.6 g/m{sup 3} h the removal efficiency of aromatic hydrocarbons decreased from 90 to 70 %, while that of the aliphatic components decreased much more significantly from 60 to 10 % after six months of operation. The removal rate and efficiency achieved for total petroleum hydrocarbons were 13 g/m{sup 3} h and 45 %, respectively. The microbial strains and genera of culturable cells in the inoculum and in the biofilm after six months of gasoline degradation were evaluated. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  15. Copper vapor laser modular packaging assembly

    Science.gov (United States)

    Alger, Terry W. (Tracy, CA); Ault, Earl R. (Dublin, CA); Moses, Edward I. (Castro Valley, CA)

    1992-01-01

    A modularized packaging arrangement for one or more copper vapor lasers and associated equipment is disclosed herein. This arrangement includes a single housing which contains the laser or lasers and all their associated equipment except power, water and neon, and means for bringing power, water, and neon which are necessary to the operation of the lasers into the container for use by the laser or lasers and their associated equipment.

  16. Development of ITER TF Cable-in-Conduit Conductors and Their Characteristics

    International Nuclear Information System (INIS)

    As a participant taking part in the ITER TF conductor R and D program, we developed two toroidal field conductors with variations of conduit thickness resulting in the different void fraction of the conductors. The estimated void fractions of the conductors are 31% and 33%. In this paper we present the details of the TF conductor development and performance test results of them carried out by the measurement of current sharing temperature under cyclic loading. Regarding the conductor development, the internal-Sn-processed Nb3Sn strand characteristics, strand cabling, twist pitch and characteristics of the conduit materials are presented. For the understanding of the conductor design and performance, the conductor test results are presented and the effect of the conductor design parameters such as void fraction and twist pitch is discussed based on the results.

  17. AC losses and stability on large cable-in-conduit superconductors

    Science.gov (United States)

    Bruzzone, Pierluigi

    1998-12-01

    The cable-in-conduit superconductors are preferred for applications where the AC losses and stability are a major concern, e.g., fusion magnets and SMES. A review of coupling currents loss results for both NbTi and Nb 3Sn cable-in-conduit conductors (CICC) is presented and the AC loss relevant features are listed, with special emphasis for the role of the interstrand resistance and strand coating. The transient stability approach for CICCs is discussed and the analytical models are quoted as well as the relevant experimental database. The likely spectrum of transient disturbance in CICC is reviewed and the need to account for interstrand current sharing in the design is outlined. Eventually a practical criterion for the interstrand resistance is proposed to link the stability and AC loss design.

  18. Crab burrows as conduits for groundwater-surface water exchange in Bangladesh

    Science.gov (United States)

    Stahl, Mason O.; Tarek, M. H.; Yeo, Darren C. J.; Badruzzaman, A. B. M.; Harvey, Charles F.

    2014-12-01

    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 conduit 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 conduits for groundwater recharge.

  19. VAPOR PRESSURES AND HEATS OF VAPORIZATION OF PRIMARY COAL TARS

    Energy Technology Data Exchange (ETDEWEB)

    Eric M. Suuberg; Vahur Oja

    1997-07-01

    This project had as its main focus the determination of vapor pressures of coal pyrolysis tars. It involved performing measurements of these vapor pressures and from them, developing vapor pressure correlations suitable for use in advanced pyrolysis models (those models which explicitly account for mass transport limitations). This report is divided into five main chapters. Each chapter is a relatively stand-alone section. Chapter A reviews the general nature of coal tars and gives a summary of existing vapor pressure correlations for coal tars and model compounds. Chapter B summarizes the main experimental approaches for coal tar preparation and characterization which have been used throughout the project. Chapter C is concerned with the selection of the model compounds for coal pyrolysis tars and reviews the data available to us on the vapor pressures of high boiling point aromatic compounds. This chapter also deals with the question of identifying factors that govern the vapor pressures of coal tar model materials and their mixtures. Chapter D covers the vapor pressures and heats of vaporization of primary cellulose tars. Chapter E discusses the results of the main focus of this study. In summary, this work provides improved understanding of the volatility of coal and cellulose pyrolysis tars. It has resulted in new experimentally verified vapor pressure correlations for use in pyrolysis models. Further research on this topic should aim at developing general vapor pressure correlations for all coal tars, based on their molecular weight together with certain specific chemical characteristics i.e. hydroxyl group content.

  20. Preliminary Experience with GORE-TEX® Grafting for Right Ventricle-Pulmonary Artery Conduits

    OpenAIRE

    Molina, J Ernesto

    1986-01-01

    A consecutive series of 12 patients between the ages of 6½ and 37 years underwent implantation of venous ventricle-pulmonary artery conduits. 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...

  1. CO2 outgassing in a combined fracture and conduit karst aquifer near lititz spring, Pennsylvania

    Science.gov (United States)

    Toran, L.; Roman, E.

    2006-01-01

    Lititz Spring in southeastern Pennsylvania and a nearby domestic well were sampled for 9 months. Although both locations are connected to conduits (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 conduit 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 conduit. 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 conduit flow in karst aquifers benefited here by geochemical modeling and calculation of PCO2 values. ?? 2006 Geological Society of America.

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

    OpenAIRE

    Mihai, R; Florescu, IP; Coroiu, V; A. Oancea; 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 determi...

  3. AC losses for the prototype cable-in-conduit conductors for NET

    Energy Technology Data Exchange (ETDEWEB)

    Bruzzone, P.; Bottura, L. (Max-Planck-Institut fuer Plasmaphysik, Garching (Germany)); Eikelboom, J. (ECN Petten, P.B.1, NL-1755 ZG Petten (NL)); Roovers, A.J.M. (Technische Hogeschool Twente, Enschede (Netherlands))

    1992-01-01

    In this paper the AC losses requirement for the superconducting coils of the Next European Torus (NET) project are discussed on the basis of the pulsed field scenario and plasma disruptions. The AC losses test results on the prototype 40 kA cable-in-conduit superconductors developed for NET are presented: the performance achieved is compared with the target. Some recommendations are made for work to be done.

  4. The strength and permeability of tuffisite-bearing andesite in volcanic conduits

    OpenAIRE

    Kolzenburg, S.; Heap, M.J.; Lavallée, Y.; Russell, J. K.; Meredith, P.G.; Dingwell, D. B.

    2012-01-01

    Tuffisites result from volcanically-induced subsurface fragmentation, transport and deposition, and are common in explosive volcanic environments. Their study provides direct insight to explosive volcanic processes operating within volcanic conduits. Here we report the influence of tuffisite veins on the fundamental physical properties of andesitic rocks. We find that: (1) strength is unaffected by the presence and/or orientation of tuffisites, (2) permeability doubles when ...

  5. Biosorption of Copper by a Bacterial Biofilm on a Flexible Polyvinyl Chloride Conduit

    OpenAIRE

    Qureshi, Fouad M.; BADAR, UZMA; Ahmed, Nuzhat

    2001-01-01

    Inexpensive technologies with less-than-optimal efficiencies as a strategy for countering economic restraints to pollution control have been evaluated by using a laboratory-scale biotreatment process for copper-containing effluent. Economizing measures include the use of polyvinyl chloride (PVC) cylinders fashioned from commercially available flexible PVC conduit to support a biofilm that was cultured in an inexpensive medium prepared in wastewater. The biofilm was challenged by aqueous coppe...

  6. Ceramic fiber blanket wrap for fire protection of cable trays and conduits

    International Nuclear Information System (INIS)

    In some areas of nuclear power plants, cables of redundant electrical systems, which are necessary for the safe shutdown of the reactor, are in close proximity. If a fire should occur in one of these areas, both electrical systems could be destroyed before the fire is extinguished and control of the reactor may be lost. A ceramic fiber blanket was evaluated as a fire protective wrap around cable trays and conduits. 2 refs

  7. Effect of Surface Pore Structure of Nerve Guide Conduit on Peripheral Nerve Regeneration

    OpenAIRE

    Oh, Se Heang; Kim, Jin Rae; Kwon, Gu Birm; Namgung, Uk; Song, Kyu Sang; Lee, Jin Ho

    2012-01-01

    Polycaprolactone (PCL)/Pluronic F127 nerve guide conduits (NGCs) with different surface pore structures (nano-porous inner surface vs. micro-porous inner surface) but similar physical and chemical properties were fabricated by rolling the opposite side of asymmetrically porous PCL/F127 membranes. The effect of the pore structure on peripheral nerve regeneration through the NGCs was investigated using a sciatic nerve defect model of rats. The nerve fibers and tissues were shown to have regener...

  8. Response of Various Conduit Arteries in Tachycardia- and Volume Overload-Induced Heart Failure

    OpenAIRE

    Lu, Xiao; Zhang, Zhen-Du; Guo, Xiaomei; Choy, Jenny Susana; Yang, Junrong; Svendsen, Mark; Kassab, Ghassan

    2014-01-01

    Although hemodynamics changes occur in heart failure (HF) and generally influence vascular function, it is not clear whether various HF models will affect the conduit vessels differentially or whether local hemodynamic forces or systemic factors are more important determinants of vascular response in HF. Here, we studied the hemodynamic changes in tachycardia or volume-overload HF swine model (created by either high rate pacing or distal abdominal aortic-vena cava fistula, respectively) on ca...

  9. Endothelial barrier dysfunction in diabetic conduit arteries: a novel method to quantify filtration

    OpenAIRE

    Lu, Xiao; Huxley, Virginia H; Kassab, Ghassan S.

    2012-01-01

    The endothelial barrier plays an important role in atherosclerosis, hyperglycemia, and hypercholesterolemia. In the present study, an accurate, reproducible, and user-friendly method was used to further understand endothelial barrier function of conduit arteries. An isovolumic method was used to measure the hydraulic conductivity (Lp) of the intact vessel wall and medial-adventitial layer. Normal arterial segments with diameters from 0.2 to 5.5 mm were used to validate the method, and femoral...

  10. Constraining Crustal Volatile Release in Magmatic Conduits by Synchrotron X-ray ?-CT

    OpenAIRE

    Berg, Sylvia

    2011-01-01

    Magma-crust interaction in magma reservoirs and conduits is a crucial process during magma evolution and ascent. This interaction is recorded by crustal xenoliths that frequently show partial melting, inflation and disintegration textures. Frothy xenoliths are widespread in volcanic deposits from all types of geological settings and indicate crustal gas liberation. To unravel the observed phenomena of frothy xenolith formation we experimentally simulated the behaviour of crustal lithologies i...

  11. Role of lymphatic vessels in tumor immunity: passive conduits or active participants?

    OpenAIRE

    Lund, Amanda W.; Swartz, M A

    2010-01-01

    Research in lymphatic biology and cancer immunology may soon intersect as emerging evidence implicates the lymphatics in the progression of chronic inflammation and autoimmunity as well as in tumor metastasis and immune escape. Like the blood vasculature, the lymphatic system comprises a highly dynamic conduit system that regulates fluid homeostasis, antigen transport and immune cell trafficking, which all play important roles in the progression and resolution of inflammation, autoimmune dise...

  12. Recurrent cervical esophageal stenosis after colon conduit failure: Use of myocutaneous flap

    OpenAIRE

    Young Jo Sa; Young Du Kim; Chi Kyung Kim; Jong Kyung Park; Seok Whan Moon

    2013-01-01

    A 53-year-old male developed cervical esophageal stenosis after esophageal bypass surgery using a right colon conduit. The esophageal bypass surgery was performed to treat multiple esophageal strictures resulting from corrosive ingestion three years prior to presentation. Although the patient underwent several endoscopic stricture dilatations after surgery, he continued to suffer from recurrent esophageal stenosis. We planned cervical patch esophagoplasty with a pedicled skin flap of sternocl...

  13. Rootless cone eruption processes informed by dissected tephra deposits and conduits

    Science.gov (United States)

    Reynolds, P.; Brown, R. J.; Thordarson, T.; Llewellin, E. W.; Fielding, K.

    2015-09-01

    Rootless cones result from the explosive interaction between lava flows and underlying water-saturated sediment or volcaniclastic deposits. Rootless explosions can represent a significant far-field hazard during basaltic eruptions, but there are few detailed studies of their deposits. A rootless cone field in the 8.5 Ma Ice Harbor flow field of the Columbia River Basalt Province, NW USA, is revealed by sections through rootless conduit and cone structures. The Ice Harbor lava flow hosting the rootless cones was emplaced across a floodplain or lacustrine environment that had recently been mantled by a layer of silicic volcanic ash from a major explosive eruption. Our observations indicate a two-stage growth model for the rootless cones: (1) initial explosions generated sediment-rich tephra emplaced by fallout and pyroclastic density currents and (2) later weaker explosions that generated spatter-rich fountains. Variable explosive activity resulted in a wide range of pyroclast morphologies and vesicularities. Cross-sections through funnel-shaped conduits also show how the conduits were constructed and stabilised. The growth model is consistent with decreasing water availability with time, as inferred for rootless cones described in Iceland. The Ice Harbor rootless cones provide further lithological data to help distinguish between rootless cone-derived tephra and tephra generated above an erupting dyke.

  14. Cardiovascular effects of right ventricle-pulmonary artery valved conduit implantation in experimental pulmonic stenosis

    International Nuclear Information System (INIS)

    Right ventricle (RV)-pulmonary artery (PA) valved conduit (RPVC) implantation decreases RV systolic pressure in pulmonic stenosis (PS) by forming a bypass route between the RV and the PA. The present study evaluates valved conduits derived from canine aortae in a canine model of PS produced by pulmonary artery banding (PAB). Pulmonary stenosis was elicited using PAB in 10 conditioned beagles aged 8 months. Twelve weeks after PAB, the dogs were assigned to one group that did not undergo surgical intervention and another that underwent RPVC using denacol-treated canine aortic valved grafts (PAB+RPVC). Twelve weeks later, the rate of change in the RV-PA systolic pressure gradient was significantly decreased in the PAB+RPVC, compared with the PAB group (60.5+-16.7% vs. 108.9+-22.9%; p0.01). In addition, the end-diastolic RV free wall thickness (RVFWd) was significantly reduced in the PAB+RPVC, compared with the PAB group (8.2+-0.2 vs. 9.4+-0.7 mm; p0.05). Thereafter, regurgitation was not evident beyond the conduit valve and the decrease in RV pressure overload induced by RPVC was confirmed. The present results indicate that RPVC can be performed under a beating heart without cardiopulmonary bypass and adapted to dogs with various types of PS, including 'supra valvular' PS or PS accompanied by dysplasia of the pulmonary valve. Therefore, we consider that this method is useful for treating PS in small animals

  15. Flambage vertical des conduites en souillées Vertical Buckling of Buried Pipes

    Directory of Open Access Journals (Sweden)

    Bournazel C.

    2006-11-01

    Full Text Available Si l'apparition d'un flambage vertical des conduites rigides enfouies dans une tranchée est un phénomène assez rare, il peut ne pas en être de même pour des conduites flexibles dont les propriétés mécaniques sont de nature différente. Une étude théorique et expérimentale, ayant pour but de proposer une méthode analytique de calcul de l'apparition du flambage et de son évolution sous l'effet de la pression interne, a été réalisée. II apparaît que les conduites flexibles actuelles sont très sensibles à ce phénomène et qu'il serait nécessaire, pour l'éliminer à coup sûr, de réexaminer la structure des flexibles ou d'imaginer des artifices dans la procédure d'ensouillage Whereas the appearance of vertical buckling in rigid pipes buried in a trench is a relatively rare phenomenon, the same cannot be said for flexible pipes which have mechanical properties of a different nature. A theoretical and experimental study has been made with the aim of proposing an analytical method for computing the appearance of buckling and its evolution under the effect of outside pressure. Current flexible pipes appear to be very sensitive to this phenomenon, and to be certain of eliminating it the structure of flexible pipes should be reexamined or stratagems in the burying procedure should be devised.

  16. Continent catheterizable conduit for urinary diversion in children: Applicability and acceptability

    Directory of Open Access Journals (Sweden)

    Shailesh Solanki

    2015-01-01

    Full Text Available Background: Continent catheterizable conduit (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 conduit 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 conduit, 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.

  17. Covering sources of toxic vapors with foam

    International Nuclear Information System (INIS)

    In a case of chemical terrorism, first responders might well be confronted with a liquid source of toxic vapor which keeps spreading out its hazardous contents. With foam as an efficient and simple means, such a source could be covered up in seconds and the spread of vapors mitigated drastically. Once covered, the source could then wait for a longer time to be removed carefully and professionally by a decontamination team. In order to find foams useful for covering up toxic vapor sources, a large set of measurements has been performed in order to answer the following questions: - Which foams could be used for this purpose? - How thick should the foam cover be? - For how long would such a foam cover be effective? - Could the practical application of foam cause a spread of the toxic chemical? The toxic vapors sources included GB, GD and HD. Among the foams were 10 fire fighter foams (e.g. AFFF, protein) and the aqueous decontamination foam CASCAD. Small scale experiments showed that CASCAD is best suited for covering a toxic source; a 10 cm layer of it covers and decontaminates GB. The large scale experiments confirmed that any fire fighter foam is a suitable cover for a longer or shorter period.(author)

  18. Numerical simulation of water injection into vapor-dominated reservoirs

    Science.gov (United States)

    Pruess, K.

    1995-01-01

    Water injection into vapor-dominated reservoirs is a means of condensate disposal, as well as a reservoir management tool for enhancing energy recovery and reservoir life. We review different approaches to modeling the complex fluid and heat flow processes during injection into vapor-dominated systems. Vapor pressure lowering, grid orientation effects, and physical dispersion of injection plumes from reservoir heterogeneity are important considerations for a realistic modeling of injection effects. An example of detailed three-dimensional modeling of injection experiments at The Geysers is given.

  19. 75 FR 44982 - Arkansas Valley Conduit (AVC) and Long-Term Excess Capacity Master Contract, Fryingpan-Arkansas...

    Science.gov (United States)

    2010-07-30

    ...Arkansas Valley Conduit (AVC) and Long-Term Excess Capacity Master Contract, Fryingpan-Arkansas Project (Fry-Ark...associated with the Excess Capacity Master Contract is to issue a long-term contract to Southeastern for storage of...

  20. Linking conduit and surface activity at Arenal volcano using broadband seismometers and Doppler radar: do we need a new conduit model?

    Science.gov (United States)

    Valade, S.; Donnadieu, F. R.; Lesage, P.; Mora Fernandez, M.; Harris, A. J.; Alvarado, G. E.

    2010-12-01

    We carried out a cross-correlation of broadband seismic data and ground-based Doppler radar data obtained at Arenal (Costa Rica) in February 2005. Our aim was to gain insight into the subsurface source processes (i.e., fragmentation mechanisms operating in the shallow conduit system) and the subsequent pyroclastic emissions (i.e., plume mass loading and ascent dynamics) that characterize the transitory, mildly explosive activity at Arenal. Study of the radar and seismic waveforms revealed a non-systematic relationship between them, both exhibiting a large variety of behaviors and features, but no clear patterns could be distinguished. Pyroclastic emissions recorded by the radar also did not have a unique seismic signature: 44% of radar signals were found in association with explosion-type seismic events, 43% during episodes of tremor, and 13% during aseismic intervals. Over longer time-scales, radar event amplitudes showed no correlation with the seismic energy release rate (RSEM), nor with RSAM, nor with repose time intervals. Energy proxies obtained from coeval radar (plume energy) and seismic (explosion energy) data show significant scattering, indicating that the ratio of the seismic/radar energy was highly variable. Plume mass-loading and exit velocity thus seems only weakly correlated to the seismic energy generated by the explosion, suggesting that the seismic energy might not be a good indicator of the intensity of explosions at Arenal. The occurrence of radar echoes in different range gates indicates that several vents were active, which is consistent with the clarinet-model for tremor generation at Arenal (Lesage et al., 2006), in which fractures in the plug act as valves that control degassing, with multiple conduits explaining the occurrence of different sets of harmonic frequencies in seismic data. Fragmentation is best explained by pressure build-up below a plug obstructing the conduit. This, when a resistance threshold is overcome, fails and yields sudden decompression, allowing gas bubbles in the magma to rapidly expand and fragment the viscous host magma. Nevertheless, this model fails to explain the full spectrum of activity, recorded signals, and seismo/radar energy partitioning. Variable source depth may, though, cause variation in elastic energy radiation, and variable fragmentation mechanisms may explain varying seismic signals associated with the emissions. It is possible that non-linear, inter- and time-dependent, processes explain unstable dynamic systems such as Arenal, and are required to trigger transitions from one fragmentation mechanism to another.

  1. Injection locked oscillator system for pulsed metal vapor lasers

    Science.gov (United States)

    Warner, Bruce E. (Livermore, CA); Ault, Earl R. (Dublin, CA)

    1988-01-01

    An injection locked oscillator system for pulsed metal vapor lasers is disclosed. The invention includes the combination of a seeding oscillator with an injection locked oscillator (ILO) for improving the quality, particularly the intensity, of an output laser beam pulse. The present invention includes means for matching the first seeder laser pulses from the seeding oscillator to second laser pulses of a metal vapor laser to improve the quality, and particularly the intensity, of the output laser beam pulse.

  2. Results of a Seven-Year, Single-Centre Experience of the Long-Term Outcomes of Bovine Ureter Grafts Used as Novel Conduits for Haemodialysis Fistulas

    International Nuclear Information System (INIS)

    Purpose: To report the long-term outcomes of bovine ureter grafts as novel conduits for haemodialysis fistulas. Materials and Methods: Thirty-five patients underwent placement of a total of 40 SynerGraft 100 (SG100; CryoLife Europa®, Guildford, UK) bovine ureter grafts between April 2002 and February 2009. Prospective data were collected on all patients, including active surveillance with blood flow studies and 6-monthly duplex ultrasound studies. Main outcome measures were primary and secondary patency rates. Results: Mean follow-up time was 97 weeks (range 4–270). Thirteen patients died from unrelated causes during the study period; 12 of these patients had a functioning graft at the time of death. Five patients underwent transplantation, and all had a functioning graft at transplantation. Twelve patients had a functioning graft at the end of the study period. One hundred and ten stenoses were detected, and 97 venoplasty procedures were performed. Of the stenoses, 41.8% were located at the venous anastomosis, 12.7% within the graft, 17.3% in the outflow veins, and 28.1% in central veins. No arterial stenoses were detected. Primary patency rates were 53% at 6 months and 14% at 1 year. Secondary patency rates were 81% at 6 months, 75% at 1 year, and 56% at 2 years. Conclusions: Active surveillance and intervention was able to achieve satisfactory long-term secondary patency for these novel conduits compared with those made of PTFE seen in other studies.

  3. Conduit margin heating and deformation during the AD 1886 basaltic Plinian eruption at Tarawera volcano, New Zealand

    Science.gov (United States)

    Schauroth, Jenny; Wadsworth, Fabian B.; Kennedy, Ben; von Aulock, Felix W.; Lavallée, Yan; Damby, David E.; Vasseur, Jérémie; Scheu, Bettina; Dingwell, Donald B.

    2016-02-01

    During explosive eruptions, a suspension of gas and pyroclasts rises rapidly within a conduit. 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 conduit 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 conduit. 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 conduit 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 conduit wall and reheating of wall rock rhyolite. We couple these observations with a simple 1D conductive heating model to show what minimum temperature the conduit wall needs to reach in order to achieve a temperature above the glass transition throughout the texturally-defined deformed zone. We propose that conduit wall heating and resulting deformation influences conduit margin outgassing and may enhance the intensity of such large basaltic eruptions.

  4. Conduit fragmentation, cave patterns, and the localization of karst ground water basins: the Appalachians as a test case

    OpenAIRE

    White, W. B.; White, E.L.

    2003-01-01

    Because conduit systems in maturely developed karst aquifers have a low hydraulic resistance, aquifers drain easily and karst aquifers are subdivided into well-defined ground water basins. Ground water elevations are highest at basin boundaries; lowest at the spring where the ground water is discharged. Parameters that control the type of conduit development are (1) the effective hydraulic gradient, (2) the focus of the drainage basin, and (3) the karstifiability of the bedrock. Moderate to h...

  5. Biological conduits combining bone marrow mesenchymal stem cells and extracellular matrix to treat long-segment sciatic nerve defects

    OpenAIRE

    Yang Wang; Zheng-wei Li; Min Luo; Ya-jun Li; Ke-qiang Zhang

    2015-01-01

    The transplantation of polylactic glycolic acid conduits 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 conduit + bone marrow mesenchymal stem ...

  6. Data in support of in vivo studies of silk based gold nano-composite conduits for functional peripheral nerve regeneration

    OpenAIRE

    Suradip Das; Manav Sharma; Dhiren Saharia; Kushal Konwar Sarma; Monalisa Goswami Sarma; Bibhuti Bhusan Borthakur; Utpal Bora

    2015-01-01

    In the present data article we report the in vitro and in vivo biocompatibility of fabricated nerve conduits described in Das et al. [1]. Green synthesised gold nanoparticles (GNPs) were evaluated for their cytotoxicity in rat Schwann cells (SCTM41). We also describe herein the adhesion and proliferation of Schwann cells over the nanofibrous scaffolds. Methods describing surgical implantation of conduits in a rat sciatic nerve injury model, confirming its accurate implantation as well as the ...

  7. Biofiltration of gasoline vapors from a soil vapor extraction system

    International Nuclear Information System (INIS)

    Biofiltration was used to treat gasoline vapors produced by soil vapor extraction (SVE) from an area contaminated by a leaking underground gasoline tank. The biofilter was installed upstream of an activated carbon unit. The biofilter removed 25--50% of the vapors in the early months of the project, when more volatile components dominated. Later, the vapors were mostly less volatile materials, and the biofilter removed 40--75%. This behavior was predicted by bench scale experiments. The biofilter was economically successful, and the project provided data for projecting the economic viability of biofilters in similar applications

  8. Hydrazine-Vapor Samplers

    Science.gov (United States)

    Young, Rebecca; Mcbrearty, Charles; Curran, Dan; Leavitt, Nilgun

    1994-01-01

    Active sampling unit capable of detecting hydrazine and monomethyl hydrazine vapors at levels as low as 10 ppb in air developed. Includes detachable badge holder and pump which draws air through badge holder at selectable rate of 1 or 2 L/min. Coated strip in each badge designed to align with air passage in badge holder. Two types of badge holders constructed: one has open-face design for general monitoring of air in open spaces, while other has closed-face design with viewing window and intended for sampling through small openings to detect leaks.

  9. Diamond chemical vapor deposition.

    Czech Academy of Sciences Publication Activity Database

    Kromka, Alexander

    Praha : FZÚ AV ?R, 2011 - (Remeš, Z.; Kromka, A.; Ledinský, M.), 11-16-28 ISBN 978-80-260-0911-5. [Winter educational seminar /2./. Rokytnice n. J. (CZ), 16.02.2011-18.02.2011] R&D Projects: GA MŠk(CZ) MEB0810082; GA AV ?R KAN400100701; GA ?R(CZ) GAP108/11/0794 Institutional research plan: CEZ:AV0Z10100521 Keywords : diamond * thin film * chemical vapor deposition * hot filament * microwave plasma Subject RIV: BM - Solid Matter Physics ; Magnetism

  10. Study on the Heat Transfer Numerical Analysis of Supper Low Temperature Liquefied Gas Vaporizer

    International Nuclear Information System (INIS)

    Liquefied gas vaporizer means machine to vaporize the liquefied gas as liquid nitrogen(LN2), liquefied natural gas(LNG), liquid oxygen(LO2) etc. In the air type vaporizer, the frozen dew is also created by temperature drop (below 273 K) on vaporizer surface. This problem increases as the time progresses and humidity increases. In addition, the frozen dew gradually becomes frost deposit consequently, heat transfer through vaporizer decreases because frost deposit form adiabatic sheet. Because of this reason, recent vaporizer system is installed as parallel type, this vaporizer system needs more expensive installation costs and more space. This paper was investigated on the heat transfer characteristics of liquefied gas vaporizer with super low temperature and this paper was carried out the numerical about air heating vaporizer with super low temperature. The numerical analysis on the heat transfer was studied on the effect of geometric parameters of the vaporizer, which are length 1000 mm of 4fin75le type vaporizer. 4fin75le means number of fin is 4 and height of fin is 75 mm

  11. Water vapor retrieval from OMI visible spectra

    Directory of Open Access Journals (Sweden)

    H. Wang

    2014-01-01

    optimization of retrieval windows and parameters. The Air Mass Factor (AMF is calculated using look-up tables of scattering weights and monthly mean water vapor profiles from the GEOS-5 assimilation products. We convert from SCD to Vertical Column Density (VCD using the AMF and generate associated retrieval averaging kernels and shape factors. Our standard water vapor product has a median SCD of ~ 1.3 × 1023 molecule cm?2 and a median relative uncertainty of ~ 11% in the tropics, about a factor of 2 better than that from a similar OMI algorithm but using narrower retrieval window. The corresponding median VCD is ~ 1.2 × 1023 molecule cm?2. We have also explored the sensitivities to various parameters and compared our results with those from the Moderate-resolution Imaging Spectroradiometer (MODIS and the Aerosol Robotic NETwork (AERONET.

  12. Impact of pacing modality and biventricular pacing on cardiac output and coronary conduit flow in the post-cardiotomy patient.

    LENUS (Irish Health Repository)

    Healy, David G

    2012-02-03

    We have previously demonstrated the role of univentricular pacing modalities in influencing coronary conduit flow in the immediate post-operative period in the cardiac surgery patient. We wanted to determine the mechanism of this improved coronary conduit and, in addition, to explore the possible benefits with biventricular pacing. Sixteen patients undergoing first time elective coronary artery bypass grafting who required pacing following surgery were recruited. Comparison of cardiac output and coronary conduit flow was performed between VVI and DDD pacing with a single right ventricular lead and biventricular pacing lead placement. Cardiac output was measured using arterial pulse waveform analysis while conduit flow was measured using ultrasonic transit time methodology. Cardiac output was greatest with DDD pacing using right ventricular lead placement only [DDD-univentricular 5.42 l (0.7), DDD-biventricular 5.33 l (0.8), VVI-univentricular 4.71 l (0.8), VVI-biventricular 4.68 l (0.6)]. DDD-univentricular pacing was significantly better than VVI-univentricular (P=0.023) and VVI-biventricular pacing (P=0.001) but there was no significant advantage to DDD-biventricular pacing (P=0.45). In relation to coronary conduit flow, DDD pacing again had the highest flow [DDD-univentricular 55 ml\\/min (24), DDD-biventricular 52 ml\\/min (25), VVI-univentricular 47 ml\\/min (23), VVI-biventricular 50 ml\\/min (26)]. DDD-univentricular pacing was significantly better than VVI-univentricular (P=0.006) pacing but not significantly different to VVI-biventricular pacing (P=0.109) or DDD-biventricular pacing (P=0.171). Pacing with a DDD modality offers the optimal coronary conduit flow by maximising cardiac output. Biventricular lead placement offered no significant benefit to coronary conduit flow or cardiac output.

  13. Laboratory analog and numerical study of groundwater flow and solute transport in a karst aquifer with conduit and matrix domains.

    Science.gov (United States)

    Faulkner, Jonathan; Hu, Bill X; Kish, Stephen; Hua, Fei

    2009-11-01

    New mathematical and laboratory methods have been developed for simulating groundwater flow and solute transport in karst aquifers having conduits imbedded in a porous medium, such as limestone. The Stokes equations are used to model the flow in the conduits 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 conduit and matrix domains of a karst aquifer. The conduit 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 conduit 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 conduit 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 conduit 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. PMID:19767123

  14. Troubles des conduites alimentaires et tempérament cyclothymique: étude transversale à propos de 107 étudiants Tunisiens

    Science.gov (United States)

    Jaweher, Masmoudi; Sonda, Trabelsi; Uta, Ouali; Inès, Feki; Rim, Sallemi; Imene, Baati; Abdelaziz, Jaoua

    2014-01-01

    Introduction Les objectifs de notre étude ont été d'estimer la prévalence des troubles des conduites alimentaires (TCA) chez les jeunes tunisiens et étudier la relation entre le tempérament cyclothymique et les TCA. Méthodes Nous avons ainsi mené une étude transversale descriptive et analytique. Elle a concerné 107 étudiants de l'Institut de Presse et des Sciences de l'Information de la Manouba, Tunisie. Pour l’évaluation des TCA, nous avons procédé par la passation de l'auto questionnaire EAT 40, dans sa version validée en Tunisie. C'est l'outil le plus utilisé pour le dépistage des TCA dans le monde. Pour l’évaluation du tempérament cyclothymique, nous avons utilisé le TEMPS A dans sa version arabe validée. Une fiche épidémiologique associée a permis de recueillir quelques facteurs sociodémographiques et hygiéno-diététiques. Résultats La prévalence des troubles de conduites alimentaires a été de 24,3%. Le pourcentage des étudiants ayant un score de tempérament cyclothymique ?14 a été de 37,4%. Une association a été trouvée entre les troubles de conduites alimentaires et le tempérament affectif cyclothymique que ce soit selon l'approche dimensionnelle (p=0,005) ou selon celle catégorielle (p=0,046). Le tempérament cyclothymique multiplie par deux le risque de développer un TCA chez les étudiants de sexe féminin (p=0,04). Conclusion Es TCA sont fréquents chez nos étudiants particulièrement de sexe féminin. De plus, la présence d'un tempérament cyclothymique associé permettrait de suspecter doublement une appartenance au spectre bipolaire et devrait conduire à une attention particulière de la part du clinicien pour définir au mieux les stratégies thérapeutiques. PMID:25404977

  15. Vapor-droplet flow equations

    International Nuclear Information System (INIS)

    General features of a vapor-droplet flow are discussed and the equations expressing the conservation of mass, momentum, and energy for the vapor, liquid, and mixture using the control volume approach are derived. The phenomenological laws describing the exchange of mass, momentum, and energy between phases are also reviewed. The results have application to development of water-dominated geothermal resources

  16. ITER Model Coil Tests Overview: Nb3Sn Strand Properties in Cable-in-Conduit-Conductors

    Energy Technology Data Exchange (ETDEWEB)

    Martovetsky, N N

    2003-04-14

    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 Conduit 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.

  17. Self-field effects in NbTi subsize cable-in-conduit conductors

    Science.gov (United States)

    Wesche, R.; Stepanov, B.; Anghel, A.; Huber, S.; Pasztor, G.; Vogel, M.; Bruzzone, P.

    2004-01-01

    In the framework of the conductor optimisation task (CONDOPT) five NbTi subsize cable-in-conduit conductors with parametric variations were fabricated. The DC performance of these conductors tested in the SULTAN test facility [IEEE Trans. Appl. Supercond. 12 (2002) 520] and the strand properties including the voltage-current characteristic, are compared. The results clearly indicate that the current carrying capacity of the conductors is considerably reduced due to the self-field. In conductors with a hindered interstrand current sharing, the critical current has been found to be even below the predicted value at the peak field, suggesting an uneven current distribution among the strands.

  18. Methods for coating conduit interior surfaces utilizing a thermal spray gun with extension arm

    Science.gov (United States)

    Moore, Karen A. (Idaho Falls, ID); Zatorski, Raymond A. (East Hampton, CT)

    2007-10-02

    Systems and methods for applying a coating to an interior surface of a conduit. 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.

  19. Modeling of butt joint composed of Nb3Sn cable-in-conduit conductors

    International Nuclear Information System (INIS)

    To evaluate butt joint fabrication technology of Nb3Sn cable-in-conduit (CIC) conductors, joint resistance and quench current were measured using a joint sample developed for the JT-60SA central solenoid (CS) coil. The measurements indicate that the butt joint fulfilled the design requirements. To simulate the butt joint characteristics, a one-dimensional numerical model simplifying the butt joint configuration was developed. Using the model, joint resistance and quench current of the butt joint were calculated. The calculations were in good agreement with the measurements. As a result, the model is valid for butt joint simulations. (author)

  20. Thermal-hydraulic simulation of helium expulsion from a cable-in-conduit conductor

    International Nuclear Information System (INIS)

    This paper presents simulation results of a quenching cable-in-conduit conductor (CICC) for application in Superconducting Magnetic Energy Storage (SMES). The details of the model and its computational implementation (the code HEDUMP) are discussed. An extensive verification process shows that HEDUMP can accurately model a quenching CICC. Preliminary results of the simulation are given and discussed. In particular, the normal zone propagation is studied. It is shown that CICCs exhibit a thermohydraulic quench back behavior whereby superconducting regions ahead of the normal front are suddenly driven normal by frictional dissipation and/or compression heating of the fluid

  1. Mid-term patency of the inverted left internal thoracic artery conduit.

    Science.gov (United States)

    Nezic, Dusko G; Bojovic, Zeljko R; Milicic, Miroslav D; Antonic, Zelimir D; Boricic, Mladen I; Micovic, Slobodan V

    2014-11-01

    In order to expand the revascularization of the left anterior descending coronary artery, we have applied the inverted left internal thoracic artery (left internal thoracic artery [LITA] transected near its origin, thus supplied by retrograde flow from superior epigastric and musculophrenic arteries) in carefully selected cases (four patients). The 64-slice multidetector row computed tomographic scans performed postoperatively (range, 6 to 40 days), as well as the scans performed in the follow-up period (range, 18 to 35 months) showed preserved inverted LITA conduits with thrombolysis in myocardial infarction (TIMI) 3 flow in all patients. PMID:25100203

  2. Parametric study of the stability margins of cable-in-conduit superconductors: experiment

    International Nuclear Information System (INIS)

    In a previous experiment on the stability of cable-in-conduit superconductors, we sometimes observed multivalued stability margins, which we attributed to strong heating-induced transient flows. We proposed a schematic theory from which we derived a scaling relation for the limiting current below which the stability margin is always singlevalued. Measurements at different magnetic fields are used to test the scaling with critical temperature and resistivity. We also examine the scaling with heated length and heat pulse duration. The results of these experiments are given and compared with theory

  3. Parametric study of the stability margins of cable-in-conduit superconductors: experiment

    Energy Technology Data Exchange (ETDEWEB)

    Lue, J.W.; Miller, J.R.

    1980-01-01

    In a previous experiment on the stability of cable-in-conduit superconductors, we sometimes observed multivalued stability margins, which we attributed to strong heating-induced transient flows. We proposed a schematic theory from which we derived a scaling relation for the limiting current below which the stability margin is always singlevalued. Measurements at different magnetic fields are used to test the scaling with critical temperature and resistivity. We also examine the scaling with heated length and heat pulse duration. The results of these experiments are given and compared with theory.

  4. ITER Model Coil tests overview: Nb3Sn strand properties in cable-in-conduit conductors

    International Nuclear Information System (INIS)

    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 cable-in-conduit conductor (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

  5. ITER Model Coil Tests Overview: Nb3Sn Strand Properties in Cable-in-Conduit-Conductors

    International Nuclear Information System (INIS)

    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 Conduit 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

  6. A dynamic error analysis of vapor fraction measurements using neutron radiography

    International Nuclear Information System (INIS)

    A video-image analysis technique has been developed to extract average vapor fractions from real-time videotaped neutron attenuation. This consists of measuring the gray-level distribution throughout the flow region illuminated by the thermal neutron beam. In real-time video images, liquid regions appear dark (high neutron removal), and vapor appears light. It is a common practice to average the time-dependent brightness information (gray-level data) and then process this information to produce a spatial distribution of time-averaged vapor fraction over the conduit. Such a time-averaging technique can cause an error (dynamic error) that is related to fluctuations in the local density of the two-phase fluid. It results from the fact that the logarithm of the time-averaged intensity of the transmitted neutron beam (count-mode measure) is not equal to the time-averaged value of the logarithm of the intensity of the beam that is considered to be exact (exact measure). An analysis of the dynamic error was conducted to quantify the maximum errors achievable in the neutron radiography technique developed for vapor fraction measurements

  7. Vapor pressure measured with inflatable plastic bag

    Science.gov (United States)

    1965-01-01

    Deflated plastic bag in a vacuum chamber measures initial low vapor pressures of materials. The bag captures the test sample vapors and visual observation of the vapor-inflated bag under increasing external pressures yields pertinent data.

  8. Physical rock properties in and around a conduit zone by well-logging in the Unzen Scientific Drilling Project, Japan

    Science.gov (United States)

    Ikeda, R.; Kajiwara, T.; Omura, K.; Hickman, S.

    2008-01-01

    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 conduit. Conduit drilling (USDP-4) was conducted in 2004, which targeted the magma conduit 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 conduit, 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 conduits for degassing during magma ascent. ?? 2008 Elsevier B.V.

  9. Vapor Pressure, Vapor Composition and Fractional Vaporization of High Temperature Lavas on Io

    Science.gov (United States)

    Fegley, B., Jr.; Schaefer, L.; Kargel, J. S.

    2003-01-01

    Observations show that Io's atmosphere is dominated by SO2 and other sulfur and sulfur oxide species, with minor amounts of Na, K, and Cl gases. Theoretical modeling and recent observations show that NaCl, which is produced volcanically, is a constituent of the atmosphere. Recent Galileo, HST and ground-based observations show that some volcanic hot spots on Io have extremely high temperatures, in the range 1400-1900 K. At similar temperatures in laboratory experiments, molten silicates and oxides have significant vapor pressures of Na, K, SiO, Fe, Mg, and other gases. Thus vaporization of these species from high temperature lavas on Io seems likely. We therefore modeled the vaporization of silicate and oxide lavas suggested for Io. Our results for vapor chemistry are reported here. The effects of fractional vaporization on lava chemistry are given in a companion abstract by Kargel et al.

  10. Multiwalled CNT-pHEMA composite conduit for peripheral nerve repair.

    Science.gov (United States)

    Arslantunali, D; Budak, G; Hasirci, V

    2014-03-01

    A nerve conduit is designed to improve peripheral nerve regeneration by providing guidance to the nerve cells. Conductivity of such guides is reported to enhance this process. In the current study, a nerve guide was constructed from poly(2-hydroxyethyl methacrylate) (pHEMA), which was loaded with multiwalled carbon nanotubes (mwCNT) to introduce conductivity. PHEMA hydrogels were designed to have a porous structure to facilitate the transportation of the compounds needed for cell nutrition and growth and also for waste removal. We showed that when loaded with relatively high concentrations of mwCNTs (6%, w/w in hydrogels), the pHEMA guide was more conductive and more hydrophobic than pristine pHEMA hydrogel. The mechanical properties of the composites were better when they carried mwCNT. Elastic modulus of 6% mwCNT loaded pHEMA was twofold higher (0.32 ± 0.06 MPa) and similar to that of the soft tissues. Electrical conductivity was significantly improved (11.4-fold) from 7 × 10(-3) ?(-1).cm(-1) (pHEMA) to 8.0 × 10(-2) ?(-1).cm(-1) (6% mwCNT loaded pHEMA). On application of electrical potential, the SHSY5Y neuroblastoma cells seeded on mwCNTs carrying pHEMA maintained their viability, whereas those on pure pHEMA could not, indicating that mwCNT helped conduct electricity and make them more suitable as nerve conduits. PMID:23554154

  11. Age-related changes in biomechanical properties of transgenic porcine pulmonary and aortic conduits

    International Nuclear Information System (INIS)

    The limitations associated with conventional valve prosthesis have led to a search for alternatives. One potential approach is tissue engineering. Most tissue engineering studies have described the biomechanical properties of heart valves derived from adult pigs. However, because one of the factors affecting the function of valve prosthesis after implantation is appropriate sizing for a given patient, it is important to evaluate the usefulness of a heart valve given the donor animal’s weight and age. The aim of this study was to evaluate how the age of a pig can influence the biomechanical and hemodynamical properties of porcine heart valve prosthesis after acellularization. Acellular porcine aortic and pulmonary valve conduits were used. Hearts were harvested from animals differing in weight and age. The biomechanical properties of the valves were then characterized using a uniaxial tensile test. Moreover, computer simulations based on the finite element method (FEM) were used to study the influence of biomechanical properties on the hemodynamic conditions. Studying biomechanical and morphological changes in porcine heart valve conduits according to the weight and age of the animals can be valuable for developing age-targeted therapy using tissue engineering techniques. (paper)

  12. Structured photoionization continuum of superheated cesium vapor

    Science.gov (United States)

    Pichler, G.; Makdisi, Y.; Kokaj, J.; Thomas, N.; Mathew, J.

    2015-08-01

    We studied the absorption spectrum of dense cesium vapor in an all-sapphire cell with a special emphasis on the highly structured photoionization continuum. This continuum appears to be composed of atomic and molecular contributions which can be separated by means of additional superheating of the cesium vapor in the sapphire cell. This was possible due to the small amount of cesium filling which completely evaporated at a temperature of around 450 °C. This enabled the overheating of cesium dimers which greatly reduced its concentration at a temperature of 900 °C, leaving almost pure atomic Cs vapor. The analysis of the thermal destruction indicated that the highly structured molecular component of the photoionization continuum can be entirely attributed to cesium dimers. We discuss the possible origin of the structured photoionization continuum as stemming from the absorption process from the ground state of the Cs2 molecule to the doubly excited Cs2** molecule located above Cs2+ molecular ionization limit. The corresponding potential curves are subjected to mutual interactions and autoionization.

  13. Passive vapor extraction feasibility study

    International Nuclear Information System (INIS)

    Demonstration of a passive vapor extraction remediation system is planned for sites in the 200 West Area used in the past for the disposal of waste liquids containing carbon tetrachloride. The passive vapor extraction units will consist of a 4-in.-diameter pipe, a check valve, a canister filled with granular activated carbon, and a wind turbine. The check valve will prevent inflow of air that otherwise would dilute the soil gas and make its subsequent extraction less efficient. The granular activated carbon is used to adsorb the carbon tetrachloride from the air. The wind turbine enhances extraction rates on windy days. Passive vapor extraction units will be designed and operated to meet all applicable or relevant and appropriate requirements. Based on a cost analysis, passive vapor extraction was found to be a cost-effective method for remediation of soils containing lower concentrations of volatile contaminants. Passive vapor extraction used on wells that average 10-stdft3/min air flow rates was found to be more cost effective than active vapor extraction for concentrations below 500 parts per million by volume (ppm) of carbon tetrachloride. For wells that average 5-stdft3/min air flow rates, passive vapor extraction is more cost effective below 100 ppm

  14. The lithium vapor box divertor

    Science.gov (United States)

    Goldston, R. J.; Myers, R.; Schwartz, J.

    2016-02-01

    It has long been recognized that volumetric dissipation of the plasma heat flux from a fusion power system is preferable to its localized impingement on a material surface. Volumetric dissipation mitigates both the anticipated very high heat flux and intense particle-induced damage due to sputtering. Recent projections to a tokamak demonstration power plant suggest an immense upstream parallel heat flux, of order 20 GW m?2, implying that fully detached operation may be a requirement for the success of fusion power. Building on pioneering work on the use of lithium by Nagayama et al and by Ono et al as well as earlier work on the gas box divertor by Watkins and Rebut, we present here a concept for a lithium vapor box divertor, in which lithium vapor extracts momentum and energy from a fusion-power-plant divertor plasma, using fully volumetric processes. At the high powers and pressures that are projected this requires a high density of lithium vapor, which must be isolated from the main plasma in order to avoid lithium build-up on the chamber walls or in the plasma. Isolation is achieved through a powerful multi-box differential pumping scheme available only for condensable vapors. The preliminary box-wise calculations are encouraging, but much more work is required to demonstrate the practical viability of this scheme, taking into account at least 2D plasma and vapor flows within and between the vapor boxes and out of the vapor boxes to the main plasma.

  15. Passive vapor extraction feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Rohay, V.J.

    1994-06-30

    Demonstration of a passive vapor extraction remediation system is planned for sites in the 200 West Area used in the past for the disposal of waste liquids containing carbon tetrachloride. The passive vapor extraction units will consist of a 4-in.-diameter pipe, a check valve, a canister filled with granular activated carbon, and a wind turbine. The check valve will prevent inflow of air that otherwise would dilute the soil gas and make its subsequent extraction less efficient. The granular activated carbon is used to adsorb the carbon tetrachloride from the air. The wind turbine enhances extraction rates on windy days. Passive vapor extraction units will be designed and operated to meet all applicable or relevant and appropriate requirements. Based on a cost analysis, passive vapor extraction was found to be a cost-effective method for remediation of soils containing lower concentrations of volatile contaminants. Passive vapor extraction used on wells that average 10-stdft{sup 3}/min air flow rates was found to be more cost effective than active vapor extraction for concentrations below 500 parts per million by volume (ppm) of carbon tetrachloride. For wells that average 5-stdft{sup 3}/min air flow rates, passive vapor extraction is more cost effective below 100 ppm.

  16. Evaluation of mercury vapor in dental offices in Tehran

    Directory of Open Access Journals (Sweden)

    Hasani Tabatabaei M.

    2007-05-01

    Full Text Available Background and Aim: Dental Amalgam is a common restorative material for posterior teeth. Because of Hg content in the composition of amalgam, during the handling of material, mercury may release as vapor in the environment. Excess amount of mercury vapor can cause serious health problems in dental personnel. The aim of this investigation was to determine mercury vapor concentration in working environment of dentists in Tehran. Materials and Methods: 211 dental clinics were participated in this cross-sectional study. The clinics were randomly selected from different regions of Tehran (north, center, south, east and west. The dentists were asked to complete a questionnaire including items on demographic characteristics such as age, sex and work history, method of handling of amalgam, environmental characteristics and general health conditions. Environmental measurements of mercury vapor in dentists’ offices were done by mercury absorption tubes (Hydrar and personal pumps (SKC, 222-3, England as suggested in NIOSH method. Analysis of air samples was done by atomic absorption spectrophotometery (cold vapor. The data were analyzed by non-parametric tests (Kruskall Wallis, Mann-Whitney and Kendall.P<0.05 as the level of significance. Results: The mean mercury vapor concentration in dentists’ offices was 8.39(±9.68 µg/m³.There was no significant relationship between the urine mercury of dentists (3.107±3.95 and the air Hg vapor concentration of their offices. Using precapsulated amalgam showed significantly less Hg vapor than bulk amalgam (P=0.034. Also the surface area of working room and air Hg vapor (P=0.009 had a significant relationship (P=0.009 r=0.81. There was not any significant correlation between mercury vapor and other factors such as working hours per day and working days per week, squeezing of triturated amalgam or not, storage medium of set amalgam (water or fixer solution, mercury storage method and type of ventilation. Conclusion: The concentration of mercury vapor in dental offices' environment was lower than threshold limit value. Based on this study the type of amalgam (precapsulated or not and area of the working room had significant effect on the mercury vapor concentration of environment.

  17. Radical cystectomy and pelvic lymphadenectomy with ileal conduit urinary diversion and abdominal wall reconstruction: an interesting case of multidisciplinary management

    Directory of Open Access Journals (Sweden)

    Sofos SS

    2015-01-01

    Full Text Available Stratos S Sofos,1 Ciaran Walsh,2 Nigel J Parr,2 Kevin Hancock11Whiston Hospital, Prescot, 2Arrowe Park Hospital, Wirral, Merseyside, UKAbstract: The ileal conduit for urinary diversion after radical cystectomy is a well-described procedure. Furthermore, parastomal hernias, prolapse, stenosis, and retraction of the stoma have been reported as some of the more common complications of this procedure. The subsequent repair of parastomal hernias with a biological mesh and the potential of the conduit to “tunnel” through it has also been described. In this case report, we present a combined repair of a large incisional hernia with a cystectomy and a pelvic lymphadenectomy for invasive bladder cancer, with the use of a biological mesh for posterior component abdominal wall primary repair as well as for support to the ileal conduit used for urinary diversion.Keywords: incisional hernia, posterior component separation, biological mesh 

  18. High microsatellite and mitochondrial diversity in Anatolian native horse breeds shows Anatolia as a genetic conduit between Europe and Asia.

    Science.gov (United States)

    Koban, E; Denizci, M; Aslan, O; Aktoprakligil, D; Aksu, S; Bower, M; Balcioglu, B K; Ozdemir Bahadir, A; Bilgin, R; Erdag, B; Bagis, H; Arat, S

    2012-08-01

    The horse has been a food source, but more importantly, it has been a means for transport. Its domestication was one of the crucial steps in the history of human civilization. Despite the archaeological and molecular studies carried out on the history of horse domestication, which would contribute to conservation of the breeds, the details of the domestication of horses still remain to be resolved. We employed 21 microsatellite loci and mitochondrial control region partial sequences to analyse genetic variability within and among four Anatolian native horse breeds, Ayvac?k Pony, Malakan Horse, H?n?s Horse and Canik Horse, as well as samples from indigenous horses of unknown breed ancestry. The aims of the study were twofold: first, to produce data from the prehistorically and historically important land bridge, Anatolia, in order to assess its role in horse domestication and second, to analyse the data from a conservation perspective to help the ministry improve conservation and management strategies regarding native horse breeds. Even though the microsatellite data revealed a high allelic diversity, 98% of the genetic variation partitioned within groups. Genetic structure did not correlate with a breed or geographic origin. High diversity was also detected in mtDNA control region sequence analysis. Frequencies of two haplogroups (HC and HF) revealed a cline between Asia and Europe, suggesting Anatolia as a probable connection route between the two continents. This first detailed genetic study on Anatolian horse breeds revealed high diversity among horse mtDNA haplogroups in Anatolia and suggested Anatolia's role as a conduit between the two continents. The study also provides an important basis for conservation practices in Turkey. PMID:22497212

  19. Measurements of stability margins and current distribution in large-scale Nb3Sn cable-in-conduit conductors

    International Nuclear Information System (INIS)

    The main goal of the ITER Conductor Testing Program is to validate the design and the fabrication process of the CICC (Cable-In-Conduit Conductor) and its joints, in full-size samples. For testing large-scale cable-in-conduit conductors, several practical experimental techniques have been developed to specifically address the issues of conductor stability. The following described techniques enable experimentalists to quantify the effects and thus provide useful tools to improve the conductor performance in magnet applications. In this paper, the authors, present two experimental techniques: (a) stability margin calibration and (b) current distribution. Both are much needed in the laboratory for testing the conductor stability

  20. Measurements of stability margins and current distribution in large-scale Nb3Sn cable-in-conduit conductors

    Science.gov (United States)

    Shen, Stewart S.; Isono, Takaaki

    1995-03-01

    The main goal of the ITER Conductor Testing Program is to validate the design and the fabrication process of the CICC (Cable-In-Conduit Conductor) and its joints, in full-size samples. For testing large-scale cable-in-conduit conductors, several practical experimental techniques have been developed to specifically address the issues of conductor stability. The following described techniques enable experimentalists to quantify the effects and thus provide useful tools to improve the conductor performance in magnet applications. In this paper, the authors, present two experimental techniques: (a) stability margin calibration, and (b) current distribution. Both are much needed in the laboratory for testing the conductor stability.

  1. Ecoulements intermittents de gaz et de liquide en conduite verticale Intermittent Gas and Liquid Flows in a Vertical Pipe.

    OpenAIRE

    Line A.; Masbernat L.

    2006-01-01

    Le modèle présenté ici permet la pré-détermination du gradient de pression, du taux global de gaz, et de grandeurs caractéristiques de l'intermittence, dans un écoulement à poches et bouchons en conduite verticale. L'écriture des lois de conservation en moyenne phasique conditionnelle conduit à la définition d'une cellule moyenne équivalente. La fermeture du modèle est assurée par des lois de contrainte de cisaillement film-paroi, film-poche, bouchon-paroi, par une loi d'arrachage du gaz au c...

  2. Quantifying vapor drift of dicamba herbicides applied to soybean.

    Science.gov (United States)

    Egan, J Franklin; Mortensen, David A

    2012-05-01

    Recent advances in biotechnology have produced cultivars of corn, soybean, and cotton resistant to the synthetic-auxin herbicide dicamba. This technology will allow dicamba herbicides to be applied in new crops, at new periods in the growing season, and over greatly expanded areas, including postemergence applications in soybean. From past and current use in corn and small grains, dicamba vapor drift and subsequent crop injury to sensitive broadleaf crops has been a frequent problem. In the present study, the authors measured dicamba vapor drift in the field from postemergence applications to soybean using greenhouse-grown soybean as a bioassay system. They found that when the volatile dimethylamine formulation is applied, vapor drift could be detected at mean concentrations of 0.56 g acid equivalent dicamba/ha (0.1% of the applied rate) at 21 m away from a treated 18.3?×?18.3 m plot. Applying the diglycolamine formulation of dicamba reduced vapor drift by 94.0%. With the dimethylamine formulation, the extent and severity of vapor drift was significantly correlated with air temperature, indicating elevated risks if dimethylamine dicamba is applied early to midsummer in many growing regions. Additional research is needed to more fully understand the effects of vapor drift exposures to nontarget crops and wild plants. PMID:22362509

  3. Tubing For Sampling Hydrazine Vapor

    Science.gov (United States)

    Travis, Josh; Taffe, Patricia S.; Rose-Pehrsson, Susan L.; Wyatt, Jeffrey R.

    1993-01-01

    Report evaluates flexible tubing used for transporting such hypergolic vapors as those of hydrazines for quantitative analysis. Describes experiments in which variety of tubing materials, chosen for their known compatibility with hydrazine, flexibility, and resistance to heat.

  4. Portable vapor diffusion coefficient meter

    Science.gov (United States)

    Ho, Clifford K. (Albuquerque, NM)

    2007-06-12

    An apparatus for measuring the effective vapor diffusion coefficient of a test vapor diffusing through a sample of porous media contained within a test chamber. A chemical sensor measures the time-varying concentration of vapor that has diffused a known distance through the porous media. A data processor contained within the apparatus compares the measured sensor data with analytical predictions of the response curve based on the transient diffusion equation using Fick's Law, iterating on the choice of an effective vapor diffusion coefficient until the difference between the predicted and measured curves is minimized. Optionally, a purge fluid can forced through the porous media, permitting the apparatus to also measure a gas-phase permeability. The apparatus can be made lightweight, self-powered, and portable for use in the field.

  5. controlled water vapor conditions

    Directory of Open Access Journals (Sweden)

    M.A. Vásquez-A.

    2007-01-01

    Full Text Available Se presenta un estudio de la evoluci´on de las caracter´?sticas de los espectros de FTIR y la respuesta de fotoluminiscencia (PL en pel´?culas de silicio poroso (PSL oxidadas qu´?micamente y envejecidas en condiciones controladas. Las PSL se obtuvieron por el m´etodo electroqu´?mico para obtener buena uniformidad en grandes ´areas. Las mediciones de FTIR en las PSL reci´en preparadas manifiestan bandas de siliciohidrogeno asociadas con la terminaci´on en hidrogeno de superficie de silicio poroso justo despu´es del proceso de porificaci´on. Al oxidar las pel´?culas, los distintos modos de vibraci´on se modifican. Esos modos de vibraci´on se relacionan con los defectos en el oxido de silicio que recubre la superficie del silicio poroso. Los espectros de PL en muestras reci´en preparadas presentan un m´aximo en »700 nm. El espectro de PL en las PSL oxidadas qu´?micamente y luego envejecidas, en condici´on de vapor de agua saturado, se modifica fuertemente con respecto a las muestras reci´en obtenidas. Estas variaciones est´an asociadas con los cambios en la estructura de las PSL inducidos por los procesos de oxidaci´on. Los datos de FTIR y el comportamiento de la se?nal de PL nos permiten relacionar estas se?nales con los efectos de cuantizaci´on por peque?nas dimensiones e indicar que las transiciones a altas energ´?as las produce alg´un centro de defecto en la pel´?cula de ´oxido de silicio que se forma en su superficie. Las caracter´?sticas de las PSL reportadas en este trabajo son perfectamente reproducibles en las condiciones que se utilizaron para prepararlas; por ello, las pel´?culas pueden usarse en distintas aplicaciones.

  6. Coupled evolution of magma chambers and flow in conduits during large volcanic eruptions

    Science.gov (United States)

    Karlstrom, L.; Manga, M.; Rudolph, M. L.

    2010-12-01

    The largest silicic and mafic volcanic eruptions in the geologic record, Supervolcano and Large Igneous Province (LIP) eruptions, are distinguished by differences in surface emplacement mode, geologic context, magma volatile content, viscosity, and reservoir depth. However, these large eruptions also share several common features. Individual eruptions of both types emplace roughly the same total volume (10^3 - 10^4 km^3) of remarkably homogeneous magma that likely comes from a single reservoir. In addition, they both release large quantities of volatiles, and hence individual eruptions may significantly perturb global climate. We have developed a model that couples conduit flow and magma chamber deformation, allowing us to study both eruption types. Steady, one-dimensional multiphase flow of magma containing crystals, exsolved water, and CO_2 in a cylindrical conduit is coupled to pressure evolution within an ellipsoidal magma chamber beneath a free surface. LIP eruptions are characterized by gas-driven flow of mafic lava that may be sustained past the cessation of chamber overpressure, much like a siphon. Eruptions cease when the yield strength of the country rocks is reached and the (generally Moho-level) chamber or the conduit implodes, resulting in steady discharge and atmospheric volatile loading. In contrast, more shallow silicic lavas such as the Fish Canyon Tuff erupt through rapid mobilization of a long-lived crystal-rich mush. The crystal-rich mush is a yield strength fluid, which we model using the von Mises criterion for mobilization. If the trigger for mobilization of the mush leads directly to eruption, time-progressive yielding due to mass removal results in a fluid magma chamber that grows as the eruption proceeds, until free-surface stresses induce roof collapse and caldera formation. Chamber pressure evolution may be buffered by the mobilization of the mush, maintaining overpressure and high discharge throughout the eruption. This model suggests that differences between major volcanic eruption dynamics arise largely from different boundary conditions at the source region, which themselves are due to magma rheology and reservoir depth.

  7. 40 CFR 52.246 - Control of dry cleaning solvent vapor losses.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control of dry cleaning solvent vapor... cleaning solvent vapor losses. (a) For the purpose of this section, “dry cleaning operation” means that... Joaquin Valley Intrastate Air Quality Control Regions (the “Regions”), as described in 40 CFR part...

  8. Soil clean up by in-situ aeration. X. Vapor stripping of mixtures of volatile organics obeying Raoult's law

    International Nuclear Information System (INIS)

    Mathematical models are developed for the soil vapor extraction of nonaqueous phase liquid mixtures obeying Raoult's law. The models make the local equilibrium assumption for vapor and liquid, and can handle up to three components. Vapor stripping in laboratory columns, by means of a single vertical well screened at the bottom (axial symmetry) and by means of a single horizontal slotted pipe (Cartesian symmetry), are modeled. The models run on IBM PC-AT compatible microcomputers. Some representative results are given

  9. DC performance, AC loss and transient field stability of five medium size NbTi cable-in-conduit conductors with parametric variations

    Science.gov (United States)

    Wesche, Rainer; Anghel, Alexander; Stepanov, Boris; Vogel, Martin; Bruzzone, Pierluigi

    2005-12-01

    Five medium size NbTi cable-in-conduit conductors with parametric variations in the cable layout were fabricated of three different strands to investigate their DC performance, AC loss behaviour and transient stability by means of the SULTAN facility. A comparison of measured strand data and the cable performances at the same background field indicates that the current carrying capacity of the conductors is limited by the total magnetic field on the high field side. Due to the self-field contribution the total magnetic field on the high field side is considerably larger than the background field at high currents. The take-off electric fields were found to decrease with increasing quench currents, resulting in sudden take-offs for large overall current densities. Effective self-field factors are used to describe the DC performance in the current range, where the critical current and the current sharing temperature are accessible. The quench behaviour of the conductors is discussed in the framework of a model based on peak-field-induced quenches. Differences in the DC performance of the conductors are related to the variation in the transverse resistance determining the ability of the conductors to redistribute the current in the case of a current imbalance originated at the joints. This aspect was studied in more detail by modifying one of the joints allowing a defined number of subcables to be disconnected. The voltage-current characteristics of strands and cable-in-conduit conductors are compared. The reasons for cable n values deviating from the strand n values are discussed. Moreover, the effect of different transverse resistances on the AC loss behaviour and the transient field stability was investigated. Ni coating of the strands was found to be sufficient to eliminate the interstrand coupling current loss. Thus, additional subcable wraps provided no significant further loss reduction.

  10. Chemical vapor doping of transparent and conductive films of carbon nanotubes

    Science.gov (United States)

    Gao, Hongjun; Izquierdo, Ricardo; Truong, Vo-Van

    2012-09-01

    An alternative chemical vapor doping (CVDo) method for doping transparent and conductive films of carbon nanotubes (CNTs) is presented. The different effects between the traditional solution doping process and the proposed vapor doping method are compared in detail by means of optical microscopy, SEM, sheet resistance measurements, and Raman and UV-Vis-NIR spectroscopy. It was shown that the level of reduced sheet resistance was comparable for the two treatments but the vapor-treated film displayed better stability in air as well as other significant advantages that include its appropriateness for different types of flexible substrates. A mechanism for chemical vapor doping is proposed.

  11. Thermal hydraulic characteristics of a prototype CEA cable-in-conduit conductor

    International Nuclear Information System (INIS)

    The thermal hydraulic characteristics of a prototype CEA Cable-in-Conduit Conductor (CICC) have been studied in steady state and transient conditions. The supercritical helium velocity in the central channel was measured with a Pitot tube located at the down stream end of the conductor. An inductive heater, located at the center of the conductor, initiated thermally induced transient flow of the helium within the conductor. The induced flow velocity was measured as a function of Reynolds number and heat input. A calorimetric calibration technique was used to estimate the total heat input to the conductor. In a separate part of the experiment, a thermometer array was installed in the central channel to record the helium temperature. The associated reduction of central channel flow area significantly affects the thermal hydraulic characteristics of the conductor

  12. Detection of the normal zone with cowound sensors in cable-in conduit conductors

    International Nuclear Information System (INIS)

    Tokamaks in the future will use superconducting cable-in-conduit- conductors (CICC) in all poloidal field (PF) and toroidal field (TF) magnets. Conventional quench detection, the measurement of small resistive normal zone voltages (4 kV). In the quench detection design for TPX, we have considered several different locations for internal co-wound voltage sensors in the cable cross-section as the primary mechanism to cancel this inductive noise. The Noise Rejection Experiment (NRE) at LLNL has been designed to evaluate which internal locations will produce the best inductive- noise cancellation, and provide us with experimental data for comparison with previously developed theory. The details of the experiments and resulting data are presented and analyzed

  13. DC behaviour of NbTi cable-in-conduit conductors for ITER-FEAT

    International Nuclear Information System (INIS)

    Using the SULTAN test facility the d.c. behaviour of three subsize NbTi cable-in-conduit (CIC) conductors has been studied. The d.c. performance of the cables is compared with the critical currents and the current sharing temperatures expected from the strand data. As a basis for this comparison the critical current of the NbTi strands has been measured in the temperature range of 4.2-6.5 K in magnetic fields of up to 7.5 T. The d.c. performance of the NbTi subsize conductors has been found to be not significantly affected by cyclic loading. Taking into consideration the self field of the conductor the cable critical current and the current sharing temperature are in agreement with the strand data

  14. The strength and permeability of tuffisite-bearing andesite in volcanic conduits

    Directory of Open Access Journals (Sweden)

    S. Kolzenburg

    2012-03-01

    Full Text Available Tuffisites result from volcanically-induced subsurface fragmentation, transport and deposition, and are common in explosive volcanic environments. Their study provides direct insight to explosive volcanic processes operating within volcanic conduits. Here we report the influence of tuffisite veins on the fundamental physical properties of andesitic rocks. We find that: (1 strength is unaffected by the presence and/or orientation of tuffisites, (2 permeability doubles when tuffisites are oriented favorable (45 degrees to fluid flow, and (3 seismic wave velocities show a continuous increase with depth, independent of vein orientation. Although the influence of tuffisites on andesitic rock properties is modest, we emphasize that the material tested represents the post-eruptive state of tuffisite. Thus, these results delineate the upper boundary of strength and lower boundary of permeability and porosity. All evidence suggests that tuffisites become compacted and lithified on relatively short time scales, restoring the strength of the rock to their initial host rock values.

  15. Functionalized carbon nanoparticles, blacks and soots as electron-transfer building blocks and conduits.

    Science.gov (United States)

    Lawrence, Katherine; Baker, Charlotte L; James, Tony D; Bull, Steven D; Lawrence, Ruth; Mitchels, John M; Opallo, Marcin; Arotiba, Omotayo A; Ozoemena, Kenneth I; Marken, Frank

    2014-05-01

    Functionalized carbon nanoparticles (or blacks) have promise as novel active high-surface-area electrode materials, as conduits for electrons to enzymes or connections through lipid films, or as nano-building blocks in electroanalysis. With previous applications of bare nanoblacks and composites mainly in electrochemical charge storage and as substrates in fuel cell devices, the full range of benefits of bare and functionalized carbon nanoparticles in assemblies and composite (bio)electrodes is still emerging. Carbon nanoparticles are readily surface-modified, functionalized, embedded, or assembled into nanostructures, employed in bioelectrochemical systems, and incorporated into novel electrochemical sensing devices. This focus review summarizes aspects of a rapidly growing field and some of the recent developments in carbon nanoparticle functionalization with potential applications in (bio)electrochemical, photoelectrochemical, and electroanalytical processes. PMID:24616339

  16. Vein conduit associated with microsurgical suture for complete collateral digital nerve severance.

    Science.gov (United States)

    Alligand-Perrin, P; Rabarin, F; Jeudy, J; Césari, B; Saint-Cast, Y; Fouque, P-A; Raimbeau, G

    2011-06-01

    The aim of this study is to present the long term results of a series of 53 vein conduit grafts as first line therapy to repair complete severance of one or more collateral digital nerves. The surgical technique included an epi-perineural suture of the nerve under minimal tension, associated with a vein graft harvested from the back of the hand to cover the nerve. None of the patients presented with a neuroma, spontaneous pain or had stopped using the injured finger. Sensibility results were good or very good in 67% of cases. The scar at the donor site was very light or invisible. A total of 96% of patients were satisfied or very satisfied. This simple technique, by protecting the injured nerve, results in a rate of sensory nerve recovery that is comparable or better than that of other series in the literature, without neuroma and with minimal scarring at the donor site. PMID:21531189

  17. Recurrent cervical esophageal stenosis after colon conduit failure: Use of myocutaneous flap

    Directory of Open Access Journals (Sweden)

    Young Jo Sa

    2013-01-01

    Full Text Available A 53-year-old male developed cervical esophageal stenosis after esophageal bypass surgery using a right colon conduit. The esophageal bypass surgery was performed to treat multiple esophageal strictures resulting from corrosive ingestion three years prior to presentation. Although the patient underwent several endoscopic stricture dilatations after surgery, he continued to suffer from recurrent esophageal stenosis. We planned cervical patch esophagoplasty with a pedicled skin flap of sternocleidomastoid (SCM muscle. Postoperative recovery was successful, and the patient could eat a solid meal without difficulty and has been well for 18 mo. SCM flap esophagoplasty is an easier and safer method of managing complicated and recurrent cervical esophageal strictures than other operations.

  18. Pockets, conduits, channels, and plumes: links to volcanism and orogeny in the rollback dominated western Mediterranean

    Science.gov (United States)

    Miller, Meghan S.; Sun, Daoyuan; O'Driscoll, Leland; Becker, Thorsten W.; Holt, Adam; Diaz, Jordi; Thomas, Christine

    2015-04-01

    Detailed mantle and lithospheric structure from the Canary Islands to Iberia have been imaged with data from recent temporary deployments and select permanent stations from over 300 broadband seismometers. The stations extended across Morocco and Spain as part of the PICASSO, IberArray, and Morocco-Münster experiments. We present results from S receiver functions (SRF), shear wave splitting, waveform modeling, and geodynamic models that help constrain the tectonic evolution of the westernmost Mediterranean, including orogenesis of the Atlas Mountains and occurrence of localized alkaline volcanism. Our receiver function images, in agreement with previous geophysical modeling, show that the lithosphere is thin (~65 km) beneath the Atlas, but thickens (~100 km) over a very short length scale at the flanks of the mountains. We find that these dramatic changes in lithospheric thickness also correspond to dramatic decreases in delay times inferred from S and SKS splitting observations of seismic anisotropy. Pockets and conduits of low seismic velocity material below the lithosphere extend along much of the Atlas to Southern Spain and correlate with the locations of Pliocene-Quaternary magmatism. Waveform analysis from the USC linear seismic array across the Atlas Mountains constrains the position, shape, and physical characteristics of one localized, low velocity conduit that extends from the uppermost mantle (~200 km depth) up to the volcanoes in the Middle Atlas. The shape, position and temperature of these seismically imaged low velocity anomalies, topography of the base of the lithosphere, morphology of the subducted slab beneath the Alboran Sea, position of the West African Craton and correlation with mantle flow inferred from shear wave splitting suggest that the unusually high topography of the Atlas Mountains and isolated recent volcanics are due to active mantle support that may be from material channeled from the Canary Island plume.

  19. Theory and modelling of quench in cable-in-conduit superconducting magnets

    International Nuclear Information System (INIS)

    A new simple, self consistent theoretical model is presented that describes the phenomena of quench propagation in Cable-In-Conduit superconducting magnets. The model (Quencher) circumvents many of the difficulties associated with obtaining numerical solutions in more general existing models. Specifically, a factor of 30-50 is gained in CPU time over the general, explicit time dependent codes used to study typical quench events. The corresponding numerical implementation of the new model is described and the numerical results are shown to agree very well with those of the more general models, as well as with experimental data. Further, well justified approximations lead to the MacQuench model that is shown to be very accurate and considerably more efficient than the Quencher model. The MacQuench code is suitable for performing quench studies on a personal computer, requiring only several minutes of CPU time. In order to perform parametric studies on new conductor designs it is required to utilize a model such as MacQuench because of the high computational efficiency of this model. Finally, a set of analytic solutions for the problem of quench propagation in Cable-In-Conduit Conductors is presented. These analytic solutions represent the first such results that remain valid for the long time scales of interest during a quench process. The assumptions and the resulting simplifications that lead to the analytic solutions are discussed, and the regimes of validity of the various approximations are specified. The predictions of the analytic results are shown to be in very good agreement with numerical as well as experimental results. Important analytic scaling relations are verified by such comparisons, and the consequences of some of these scalings on currently designed superconducting magnets are discussed

  20. Integrating Laboratory and Numerical Decompression Experiments to Investigate Fluid Dynamics into the Conduit

    Science.gov (United States)

    Spina, Laura; Colucci, Simone; De'Michieli Vitturi, Mattia; Scheu, Bettina; Dingwell, Donald Bruce

    2015-04-01

    The study of the fluid dynamics of magmatic melts into the conduit, where direct observations are unattainable, was proven to be strongly enhanced by multiparametric approaches. Among them, the coupling of numerical modeling with laboratory experiments represents a fundamental tool of investigation. Indeed, the experimental approach provide invaluable data to validate complex multiphase codes. We performed decompression experiments in a shock tube system, using pure silicon oil as a proxy for the basaltic melt. A range of viscosity comprised between 1 and 1000 Pa s was investigated. The samples were saturated with Argon for 72h at 10MPa, before being slowly decompressed to atmospheric pressure. The evolution of the analogue magmatic system was monitored through a high speed camera and pressure sensors, located into the analogue conduit. The experimental decompressions have then been reproduced numerically using a multiphase solver based on OpenFOAM framework. The original compressible multiphase Openfoam solver twoPhaseEulerFoam was extended to take into account the multicomponent nature of the fluid mixtures (liquid and gas) and the phase transition. According to the experimental conditions, the simulations were run with values of fluid viscosity ranging from 1 to 1000 Pa s. The sensitivity of the model has been tested for different values of the parameters t and D, representing respectively the relaxation time for gas exsolution and the average bubble diameter, required by the Gidaspow drag model. Valuable range of values for both parameters are provided from experimental observations, i.e. bubble nucleation time and bubble size distribution at a given pressure. The comparison of video images with the outcomes of the numerical models was performed by tracking the evolution of the gas volume fraction through time. Therefore, we were able to calibrate the parameter of the model by laboratory results, and to track the fluid dynamics of experimental decompression.

  1. Calculation of vaporization rates assuming various rate determining steps: Application to the resistojet

    Science.gov (United States)

    May, C. E.

    1984-01-01

    The various steps that could control the vaporization rate of a material are discussed. These steps include the actual vaporization, flow rate of matrix gas, chemical reaction, gas diffusion, and solid state diffusion. The applicable equations have been collected from diverse appropriate sources, and their use is explained. Rate equations are derived for conditions where more than one step is rate controlling. Calculations are made for two model materials: rhenium which vaporizes congruently, and tantalum carbide which vaporizes incongruently. The case of vaporization under thermal gradient conditions is also treated. The existence of a thermal gradient in the resistojet means that the vaporization rate of a material may be only one thousandth of that predicted under isothermal conditions. Calculations show that rhenium might have a 100,000 hr lifetime at temperature in a 2500 C resistojet. Tantalum carbide would have a life of only 660 sec under similar conditions.

  2. A Review of Vapor Intrusion Models

    OpenAIRE

    Yao, Yijun; Suuberg, Eric M.

    2013-01-01

    A complete vapor intrusion (VI) model, describing vapor entry of volatile organic chemicals (VOCs) into buildings located on contaminated sites, generally consists of two main parts-one describing vapor transport in the soil and the other its entry into the building. Modeling the soil vapor transport part involves either analytically or numerically solving the equations of vapor advection and diffusion in the subsurface. Contaminant biodegradation must often also be included in this simulatio...

  3. Failing left ventricle to ascending aorta conduit-Hybrid implantation of a melody valve and NuMed covered stent.

    Science.gov (United States)

    Gössl, Mario; Johnson, Jonathan N; Hagler, Donald J

    2014-04-01

    We present the case of a 36-year-old woman with increasing shortness of breath, a new 3/4 diastolic murmur, and a complex history of LV outflow tract obstruction. She has undergone multiple surgeries including the replacement of her old LV apex to ascending aorta conduit with a 20-mm Gore-Tex tube graft, addition of a 24-mm homograft sutured between the conduit and the LV apex, and insertion of a 21-mm Freestyle porcine valve conduit between the Gore-Tex tube graft and allograft at age 23. The current assessment showed a failing Freestyle conduit prosthesis leading to left heart decompensation. Due to substantial surgical risk, the patient underwent successful implantation of a Melody valve into the Gore-Tex tube and exclusion of the failing Freestyle bioprosthesis with a NuMed CP stent in a hybrid procedure. The case nicely illustrates the collaborative potential of cardiovascular surgeons and interventional cardiologists in the new arena of a hybrid operating room. Complex hybrid procedures like the current one, especially those including percutaneous placements of valves, offer therapeutic options for patients that are otherwise too high risk for conventional open heart surgery. PMID:23784974

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

    International Nuclear Information System (INIS)

    Cable-In-Conduit-Conductor (CICC) alloys, exposed to Nb3Sn 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. Terrestrial analogs to lunar sinuous rilles - Kauhako Crater and channel, Kalaupapa, Molokai, and other Hawaiian lava conduit systems

    International Nuclear Information System (INIS)

    Two source vents, one explosive and one effusive erupted to form a cinder cone and low lava shield that together compose the Kalaupapa peninsula of Molokai, Hawaii, A 50-100-m-wide channel/tube system extends 2.3 km northward from kauhako crater in the center of the shield. Based on modeling, a volume of up to about 0.2 cu km of lava erupted at a rate of 260 cu m/sec to flow through the Kauhako conduit system in one of the last eruptive episodes on the peninsula. Channel downcutting by thermal erosion occurred at a rate of about 10 micron/sec to help form the 30-m-deep conduit. Two smaller, secondary tube systems formed east of the main lava channel/tube. Several other lava conduit systems on the islands of Oahu and Hawaii were also compared to the Kauhako and lunar sinuous rille systems. These other lava conduits include Whittington, Kupaianaha, and Mauna Ulu lava tubes. Morphologically, the Hawaiian tube systems studied are very similar to lunar sinuous rilles in that they have deep head craters, sinuous channels, and gentle slopes. Thermal erosion is postulated to be an important factor in the formation of these terrestrial channel systems and by analogy is inferred to be an important process involved in the formation of lunar sinuous rilles. 28 refs

  6. The effect of shear stress on human endothelial cells seeded on cylindrical viscoelastic conduits: an investigation of gene expression.

    Science.gov (United States)

    Vara, Dina S; Punshon, Geoffrey; Sales, Kevin M; Hamilton, George; Seifalian, Alexander M

    2006-11-01

    The present study assesses the effect of physiological shear stress on gene expression from human ECs (endothelial cells) seeded on a small-diameter cylindrical bypass graft constructed from nanocomposite based on poly(carbonate-silsesquioxane-bridge-urea)urethane. ECs were seeded on to 5-mm-diameter conduits, placed in a physiological flow circuit and exposed to 1 or 4 h of shear stress at 1.4+/-0.3 Pa. Subsets of conduits were incubated at 37 degrees C and 5% CO2/95% O2 for a further 4 h to determine if gene expression returned to basal levels. PCR was conducted for glyceraldehyde-3-phosphate dehydrogenase, TGFbeta-1 (transforming growth factor beta-1), COL-1 (collagen-1) and PECAM-1 (platelet/EC adhesion molecule-1). Increases in gene expression were seen following flow in nanocomposite conduits. These were significant at 4 h for TGFbeta-1, COL-1 and PECAM-1. After a 4 h recovery period, there were no significant differences in gene intensity, suggesting that this change is transient. These data prove that mRNA can be obtained from ECs seeded on tubular conduits and exposed to shear stress and that gene-expression studies can be successfully carried out. We believe this is a substantial improvement on studies based on flat sheets. PMID:16756513

  7. Análise do tratamento cirúrgico da raiz da aorta com o tubo valvulado e com a preservação da valva aórtica / Analysis of aortic root surgery with composite mechanical aortic valve conduit and valve-sparing reconstruction

    Scientific Electronic Library Online (English)

    Ricardo Ribeiro, Dias; Omar Asdrubal Vilca, Mejia; Alfredo Inácio, Fiorelli; Pablo Maria Alberto, Pomerantzeff; Altamiro Ribeiro, Dias; Charles, Mady; Noedir Antonio Groppo, Stolf.

    2010-12-01

    Full Text Available OBJETIVO: Análise comparativa dos resultados imediatos e tardios da reconstrução da raiz da aorta com o tubo valvulado e com a preservação da valva aórtica. MÉTODOS: No período de novembro de 2002 a setembro de 2009, 164 pacientes com idade média de 54 ± 15 anos, sendo 115 do sexo masculino, foram s [...] ubmetidos ao tratamento cirúrgico da raiz da aorta. Foram 125 tubos valvulados e 39 reconstruções da raiz da aorta com preservação da valva aórtica. Dezesseis por cento dos pacientes eram portadores de síndrome de Marfan e 4,3% apresentavam valva aórtica bivalvulada. Cento e quarenta e quatro (88%) pacientes foram acompanhados durante tempo médio de seguimento de 41,1 ± 20,8 meses. RESULTADOS: A mortalidade hospitalar total foi de 4,9%; sendo 5,6% nas operações com tubo valvulado e 2,6% nas preservações da valva aórtica (P Abstract in english OBJECTIVE: Comparative analysis of early and late results of aortic root reconstruction with aortic valve sparing operations and the composite mechanical valve conduit replacement. METHODS: From November 2002 to September 2009, 164 consecutive patients with mean age 54 ± 15 years, 115 male, underwen [...] t the aortic root reconstruction (125 mechanical valve conduit replacements and 39 valve sparing operations). Sixteen percent of patients had Marfan syndrome and 4.3% had bicuspid aortic valve. One hundred and forty-four patients (88%) were followed for a mean period of 41.1 ± 20.8 months. RESULTS: The hospital mortality was 4.9%, 5.6% in operations with valved conduits and 2.6% in the valve sparing procedures (P

  8. A study of pulsed gold and bismuth vapor lasers

    Science.gov (United States)

    Markova, S. V.; Petrash, G. G.; Cherezov, V. M.

    Gold and bismuth vapor lasers have been investigated with a view to developing pulsed lasers at resonance-metastable transitions for shorter wavelengths than are possible with the existing lasers of this type. It is shown that efficient lasing in the visible (red) and UV spectral regions with high mean and peak power output can be achieved at self-terminating transitions in the gold atom. It is also shown that a pulsed discharge in bismuth vapors is characterized by specific processes that can result in a substantial population of the 6p3 2D(0)3/2 level.

  9. Saturated vapor properties and scaling in the lattice gas model

    International Nuclear Information System (INIS)

    A study of the lattice gas (Ising) model shows the properties of saturated vapor in coexistence with a liquid to be independent of the system's fixed mean density ?fixed, in keeping with standard thermodynamics. This behavior ensures that Fisher scaling plots are unique, independent of ?fixed, and yield a unique characterization of the liquid-vapor phase diagram. The resulting phase diagram and critical parameters for the square lattice gas model are shown to agree with accepted values to within a few percent throughout the coexistence region

  10. ACCUMULATIVE SAFETY PERIOD OF PREMISES IN THE CASE OF THEIR POLLUTION WITH TOXIC MERCURY VAPORS

    Directory of Open Access Journals (Sweden)

    Tatyana Dmitrucha

    2013-12-01

    Full Text Available An ecological indicator is determined - accumulative period of safety in premises which means duration of the relative safety of the premises after occurrence of their pollution with mercury vapor or other toxic substances.

  11. NOVEL CERAMIC-ORGANIC VAPOR PERMEATION MEMBRANES FOR VOC REMOVAL - PHASE I

    Science.gov (United States)

    Vapor permeation holds much promise for becoming a highly efficient means of preventing VOC emissions that are now generated by a variety of stationary sources, including solvent and surface coating operations, gasoline storage operations, and printing operations. A limitation of...

  12. Benzene vapor recovery and processing

    International Nuclear Information System (INIS)

    The National Emissions Standards for Hazardous Air Pollutants, or NESHAPs, have provided a powerful motivation for interest in, and attention to, benzene vapor emissions in recent times. Benzene and its related aromatics are volatile organic compounds (VOCs), which marks them for surveillance as potential contributors to air pollution. In addition, benzene is a suspected carcinogen, which applies a special urgency to its control. The regulations governing the control of benzene emissions were issued as Title 40, Code of Federal Regulations, Part 61, subpart Y (Storage Vessels); subpart BB (Transfer Operations); and subpart FF (Waste Operations). These regulations specify very particular emission reduction guidelines for various generating sources. The problem in the hydrocarbon processing industry is to identify significant sources of benzene vapors in plants, and then to collect and process these vapors in an environmentally acceptable manner. This paper discusses various methods for collecting benzene fumes in these facilities

  13. Melt and vapor characteristics in an electron beam evaporator

    International Nuclear Information System (INIS)

    Two different approaches have been compared for the calculation of the free surface temperature Ts in cerium or copper evaporation experiments: the first method considers properties of the melt: an empirical law is used to take into account turbulent thermal convection, instabilities and characterization of the free surface. The second method considers the vapor flow expansion and connects Ts to the measured terminal temperature and terminal mean parallel velocity of the vapor jet, by direct simulation Monte Carlo calculations including an atom-atom inelastic collision algorithm. The agreement between the two approaches is better for cerium than for copper in the high characterization case. The analysis, from the point of view of the properties of the melt, of the terminal parameters of the vapor jet for the high beam powers shows that Ts and the Knudsen number at the vapour source reach a threshold when the beam power increases. (author). 12 figs., 1 tab., 21 refs

  14. Vaporization behavior of neptunium mononitride

    International Nuclear Information System (INIS)

    Vaporization behavior of NpN(s) was investigated by mass spectrometry with a Knudsen-cell in the temperature range of 1690-2030 K. It is suggested from the vapor pressure measurements that NpN(s) decomposed into Np(l) and N2(g). The free energy of formation of NpN(s) was evaluated by using the partial pressures of Np(g), the decomposition pressures of N2(g) reported previously and the free energy of formation of Np(g). The free energy of formation of NpN(s) obtained lay between those of UN and PuN reported in the literature. (orig.)

  15. Low level vapor verification of monomethyl hydrazine

    Science.gov (United States)

    Mehta, Narinder

    1990-01-01

    The vapor scrubbing system and the coulometric test procedure for the low level vapor verification of monomethyl hydrazine (MMH) are evaluated. Experimental data on precision, efficiency of the scrubbing liquid, instrument response, detection and reliable quantitation limits, stability of the vapor scrubbed solution, and interference were obtained to assess the applicability of the method for the low ppb level detection of the analyte vapor in air. The results indicated that the analyte vapor scrubbing system and the coulometric test procedure can be utilized for the quantitative detection of low ppb level vapor of MMH in air.

  16. Waste Tank Vapor Project: Tank vapor database development

    International Nuclear Information System (INIS)

    The objective of the Tank Vapor Database (TVD) Development task in FY 1994 was to create a database to store, retrieve, and analyze data collected from the vapor phase of Hanford waste tanks. The data needed to be accessible over the Hanford Local Area Network to users at both Westinghouse Hanford Company (WHC) and Pacific Northwest Laboratory (PNL). The data were restricted to results published in cleared reports from the laboratories analyzing vapor samples. Emphasis was placed on ease of access and flexibility of data formatting and reporting mechanisms. Because of time and budget constraints, a Rapid Application Development strategy was adopted by the database development team. An extensive data modeling exercise was conducted to determine the scope of information contained in the database. a A SUN Sparcstation 1000 was procured as the database file server. A multi-user relational database management system, Sybase reg-sign, was chosen to provide the basic data storage and retrieval capabilities. Two packages were chosen for the user interface to the database: DataPrism reg-sign and Business Objects trademark. A prototype database was constructed to provide the Waste Tank Vapor Project's Toxicology task with summarized and detailed information presented at Vapor Conference 4 by WHC, PNL, Oak Ridge National Laboratory, and Oregon Graduate Institute. The prototype was used to develop a list of reported compounds, and the range of values for compounds reported by the analytical laboratories using different sample containers and analysis methodologies. The prototype allowed a panel of toxicology experts to identify carcinogens and compounds whose concentrations were within the reach of regulatory limits. The database and user documentation was made available for general access in September 1994

  17. Emprego de condutos de pericárdio bovino na conexão ventrículo-arterial pulmonar: resultados tardios / Late results with the use of a valved conduit ot bovine pericardium for ventricle to pulmonary artery connection

    Scientific Electronic Library Online (English)

    Fernando Antônio, Fantini; Bayard, Gontijo Filho; Martins, Cristiane; Roberto Max, Lopes; Maria G, Horta; Leonardo F, Drumond; Marcelo Frederico de, Castro; Carla, Oliveira; Arturo, Ferrufino; João Alfredo de Paula e, Silva; Eduardo, Peredo; Juscelino Teixeira, Barbosa; Mário O, Vrandecic.

    1996-09-01

    Full Text Available A reconstrução biventricuiar de uma série de cardiopatias congênitas requer a interposição de condutos valvados ventrículo-arteriais. Com o objetivo de analisar a evolução a longo prazo de um conduto de pericárdio bovino valvulado com bíoprótese porcina sem suporte tratado com glutaraldeído, foram r [...] evistos os prontuários de 33 pacientes operados de novembro de 1985 a outubro de 1995. A idade variou de 15 dias a 18 anos (média 5,7 ± 4,3 anos). A atresia pulmonar com comunicação interventricular (CIV) foi a lesão mais freqüente (16 casos), seguida da síndrome da valva pulmonar ausente (5), truncus arteriosus (4), transposição das grandes artérias com CIV e estenose pulmonar (3) e outras (5). A mortalidade imediata foi de 18,2%, diretamente relacionada à condição pré-operatória. Vinte e três (70%) pacientes foram acompanhados por períodos que variaram de 3 meses a 10 anos (média 4,8 ± 3,0 anos). A complicação mais freqüentemente observada no seguimento tardio foi a estenose da anastomose distai do conduto, presente em 17,4% (4/23) dos pacientes. Foram reoperados 3 (13%) pacientes, sendo que 2 deles por estenose distal (p=0,02) e 1 por endocardite tardia do conduto. A mortalidade tardia foi de 17,4% (4/23), em 1 caso devido a estenose distai. A causa da estenose distal parece ser devida a retração tecidual na área de transição entre o pericárdio bovino e o tronco pulmonar. Em até 10 anos de seguimento não ocorreu calcificação significativa que prejudicasse a função tanto da valva quanto do conduto. Em conclusão, os condutos de pericárdio bovino apresentaram uma performance satisfatória como substitutos vasculares, não tendo ocorrido calcificação significativa da valva porcina ou das paredes do conduto no seguimento tardio. A incidência de estenose na anastomose distal parece estar mais relacionada a um fenômeno de retração tecidual do que a problemas técnicos. Abstract in english The biventricular repair of congenital heart diseases with an inadequate or absent ventricle to pulmonary artery connection sometimes requires the use of extracardiac conduits. In order to study the longterm outcome of a glutaraldehyde-preserved bovine pericardial conduit valved with a stentless por [...] cine aortic valve, we reviewed the data of 33 patients operated between November 1985 and October 1995. Patients ages ranged from 15 days to 18 years (mean 5.7 ± 4.3 years). Pulmonary atresia with ventricular septal defect (VSD) was the most frequent disease (16 cases), followed by tetralogy of Fallot with absent pulmonary valve (5), truncus arteriosus (4), transposition of great arteries with VSD and pulmonary stenosis (3) and other miscellaneous (5). The overall hospital mortality was 18.2% and was related to the preoperative clinical condition; 23 patients (70%) were followed by a mean of 4.8 ± 3.0 years (ranging from 3 months to 10 years). The most common late complication observed was stenosis of the anastomosis between the conduit and the pulmonary artery present in 17.4% (4/23) of the patients and was the cause of 2 later reoperations (p=0,02); another patient was reoperated for late conduit endocarditis. This complication was also the cause of 1 of the 4 late deaths (17.4%). The last patient is waiting for surgery. The development of the anastomotic stenosis was problably due to a retraction of the pericardial tissue along the transition with the thin wall of the pulmonary artery. Up to 10 years, gross calcification impairing the function of the valve or the conduit itself could not be detected. In conclusion, the bovine pericardial conduits have shown a good performance as a vascular substitute. Calcification has not been a major drawback. The righ incidence of distal stenosis appears to be more related to a shrinking of the pericardial tissue than to technical reasons.

  18. Experimental composite guidance conduits for peripheral nerve repair: An evaluation of ion release

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, X.F. [Department of Biological Sciences and Medical Engineering Design and Innovation Centre, Cork Institute of Technology, Cork (Ireland); Coughlan, A. [Inamori School of Engineering, Alfred University, Alfred, NY. 14802 (United States); O' Shea, H. [Department of Biological Sciences and Medical Engineering Design and Innovation Centre, Cork Institute of Technology, Cork (Ireland); Towler, M.R. [Inamori School of Engineering, Alfred University, Alfred, NY. 14802 (United States); Kehoe, S., E-mail: sharonkehoe@dal.ca [Department of Applied Oral Sciences, Dalhousie University, Halifax, NS, B3H 4R2 (Canada); School of Biomedical Engineering, Dalhousie University, Halifax, NS, B3H 4R2 (Canada); Boyd, D., E-mail: d.boyd@dal.ca [Department of Applied Oral Sciences, Dalhousie University, Halifax, NS, B3H 4R2 (Canada); School of Biomedical Engineering, Dalhousie University, Halifax, NS, B3H 4R2 (Canada)

    2012-08-01

    Poly (lactide-co-glycolide) (PLGA) - Pluronic F127 - glass composites have demonstrated excellent potential, from the perspective of controlled mechanical properties and cytocompatibility, for peripheral nerve regeneration. In addition to controlling the mechanical properties and cytotoxicity for such composite devices, the glass component may mediate specific responses upon implantation via degradation in the physiological environment and release of constituent elements. However, research focused on quantifying the release levels of such therapeutic ions from these experimental medical devices has been limited. To redress the balance, this paper explores the ion release profiles for Si{sup 4+}, Ca{sup 2+}, Na{sup +}, Zn{sup 2+}, and Ce{sup 4+} from experimental composite nerve guidance conduits (CNGC) comprising PLGA (at 12.5, and 20 wt.%), F127 (at 0, 2.5 and 5 wt.%) and various loadings of Si-Ca-Na-Zn-Ce glass (at 20 and 40 wt.%) for incubation periods of up to 28 days. The concentration of each ion, at various time points, was determined using Inductively Coupled Plasma-Atomic Emission Spectrometry (Perkin Elmer Optima 3000). It was observed that the Si{sup 4+}, Na{sup +}, Ca{sup 2+}, Zn{sup 2+} release from CNGCs in this study ranged from 0.22 to 6.477 ppm, 2.307 to 3.277 ppm, 40 to 119 ppm, and 45 to 51 ppm, respectively. The Ce{sup 4+} concentrations were under the minimum detection limits for the ICP instrument utilized. The results indicate that the ion release levels may be appropriate to mediate therapeutic effects with respect to peripheral nerve regeneration. The data generated in this paper provides requisite evidence to optimize composition for pre-clinical evaluation of the experimental composite. - Graphical abstract: Highlights: Black-Right-Pointing-Pointer Time-dependent degradation studies of PLGA/glass composite nerve guidance conduits (NGCs). Black-Right-Pointing-Pointer Si{sup 4+}, Na{sup +}, Ca{sup 2+} and Zn{sup 2+} release levels for the glass containing NGCs are presented. Black-Right-Pointing-Pointer Release levels may mediate therapeutic effects to provoke nerve regeneration. Black-Right-Pointing-Pointer Data provides requisite evidence to optimize composition to pre-clinical requirements.

  19. A microanalytical perspective on late stage conduit dynamics at Tungurahua and Cotopaxi Volcanoes, Ecuador

    Science.gov (United States)

    Swarr, G. J.; Garman, K. A.; Harpp, K. S.; Dufek, J.; Geist, D.

    2009-12-01

    Late-stage conduit dynamics can strongly influence the explosivity and eruption mechanisms of volatile rich magmas. Magmatic viscosity can affect bubble coalescence, differential magma-gas flow, and fragmentation style. We have examined the products of recent eruptions of an intermediate style of volcanism that produces pyroclastic density currents (PDCs) fed from low eruption columns. These boiling-over style eruptions were observed during the 2006 eruption of Tungurahua and were inferred from the deposits of the 1877 eruption of Cotopaxi. In the 2006 eruption of Tungurahua at least 56 PDCs were recorded; on the basis of observations during the eruptions, all the PDCs were attributed to the boiling over process. In eruptions from both volcanoes, juvenile bombs appear throughout the deposit, often concentrated in levees and in flow lobes. These bombs can be large (5 to 15 decimeters in diameter) and have a fragile bread-crust exterior. The majority of the smaller bombs from the Tungurahua deposits (1 to 5 decimeters in diameter) are flattened and highly vesicular with large vesicles up to 15 mm in diameter. The centers of the largest bombs (up to 1.8 meters across), however, are denser, lacking vesicles larger than 2 mm. At Cotopaxi the juvenile bombs have a similar size and density to those at Tungurahua, but lack large vesicles, instead having a relatively high abundance of vesicles less than 1 mm in diameter. Larger vesicles (up to 3 mm in diameter) are concentrated in frothy, brown to green regions in Cotopaxi deposits. Viscosity calculated using major element contents of the juvenile bombs suggests that those from Tungurahua may be more viscous than those at Cotopaxi by as much as 20 percent. We will examine the differences in bomb color, density, and crystal content at the microscopic level using LA-ICP-MS to determine small scale chemical variations. We propose that these differences at Tungurahua and Cotopaxi reflect subtle differences in magma viscosity and conduit dynamics, and that they have the potential to provide insight into the boiling-over PDC generation mechanism.

  20. Étude des perturbations conduites et rayonnées dans une cellule de commutation

    Science.gov (United States)

    Costa, F.; Forest, F.; Puzo, A.; Rojat, G.

    1993-12-01

    The principles used in static conversion and the rise of the performances of the new switching devices contribue to increase the level of electromagnetic noises emitted by electronic converters. We have studied the way how these perturbations are created and coupled through their environment in conducted and radiated mode by a switching cell. This one can work in hard switching, zero current or voltage switching modes. We first outline the general problems of electromagnetic pollution and their metrology in converters. Then we describe the experimental environment. We analyse the mechanisms of generation of parasitic signals in a switching cell related to the electrical constraints and its switching mode. The simulated results, issued of the analytical models obtained, are confronted with the experimental ones. Then we show a method to calculate analytically the E and H near fields. It has been confirmed by experimental results. At last, we present, in a synthetic manner, the main results obtained, relative to the switching mode and the electrical constraints, using a new characterizing method. Theses results will allow the designer to incorporate the electromagnetic considerations in the conception of a converter. Les principes de commutation employés en conversion statique, l'évolution des performances statiques et dynamiques des composants, contribuent à faire des dispositifs de conversion statique de puissants générateurs de perturbations conduites et rayonnées. Nous nous sommes attachés à étudier les mécanismes de génération et de couplage des perturbations, tant en mode conduit que rayonné dans des structures à une seule cellule de commutation et fonctionnant selon les trois principaux modes de commutation : commutation forcée, à zéro de courant (ZCS), et à zéro de tension (ZVS). Après la mise en évidence de la problématique de pollution électromagnétique dans les structures et leur métrologie, nous décrivons l'environnement expérimental étudié. Nous analysons ensuite les principaux mécanismes produisant les perturbations au sein d'une cellule de commutation en introduisant un certain nombre de composants parasites. Les modèles sont simulés et confrontés aux résultats expérimentaux. Nous décrivons alors une méthode, validée expérimentalement et permettant de calculer les intensités des champs E et H proches émis. Enfin, nous présentons de façon synthétique les résultats observés selon les régimes de fonctionnement de la cellule de commutation et les contraintes électriques et dynamiques qu'elle subit. Nous avons, pour ce faire, développé une méthode originale de quantification des signaux perturbateurs. Les résultats obtenus doivent permettre d'intégrer les problèmes de pollution électromagnétique au stade de la conception d'un dispositif.

  1. Experimental composite guidance conduits for peripheral nerve repair: An evaluation of ion release

    International Nuclear Information System (INIS)

    Poly (lactide-co-glycolide) (PLGA) — Pluronic F127 — glass composites have demonstrated excellent potential, from the perspective of controlled mechanical properties and cytocompatibility, for peripheral nerve regeneration. In addition to controlling the mechanical properties and cytotoxicity for such composite devices, the glass component may mediate specific responses upon implantation via degradation in the physiological environment and release of constituent elements. However, research focused on quantifying the release levels of such therapeutic ions from these experimental medical devices has been limited. To redress the balance, this paper explores the ion release profiles for Si4+, Ca2+, Na+, Zn2+, and Ce4+ from experimental composite nerve guidance conduits (CNGC) comprising PLGA (at 12.5, and 20 wt.%), F127 (at 0, 2.5 and 5 wt.%) and various loadings of Si–Ca–Na–Zn–Ce glass (at 20 and 40 wt.%) for incubation periods of up to 28 days. The concentration of each ion, at various time points, was determined using Inductively Coupled Plasma–Atomic Emission Spectrometry (Perkin Elmer Optima 3000). It was observed that the Si4+, Na+, Ca2+, Zn2+ release from CNGCs in this study ranged from 0.22 to 6.477 ppm, 2.307 to 3.277 ppm, 40 to 119 ppm, and 45 to 51 ppm, respectively. The Ce4+ concentrations were under the minimum detection limits for the ICP instrument utilized. The results indicate that the ion release levels may be appropriate to mediate therapeutic effects with respect to peripheral nerve regeneration. The data generated in this paper provides requisite evidence to optimize composition for pre-clinical evaluation of the experimental composite. - Graphical abstract: Highlights: ? Time-dependent degradation studies of PLGA/glass composite nerve guidance conduits (NGCs). ? Si4+, Na+, Ca2+ and Zn2+ release levels for the glass containing NGCs are presented. ? Release levels may mediate therapeutic effects to provoke nerve regeneration. ? Data provides requisite evidence to optimize composition to pre-clinical requirements.

  2. Modeling spatially and temporally varied hydraulic behavior of a folded karst system with dominant conduit drainage at catchment scale, Hochifen-Gottesacker, Alps

    Science.gov (United States)

    Chen, Zhao; Goldscheider, Nico

    2014-06-01

    Karst aquifers are important for freshwater supply, but difficult to manage, due to highly variable water levels and spring discharge rates. Conduits are crucial for groundwater flow in karst aquifers, but their location is often unknown, thus limiting the applicability and validity of numerical models. We have applied a conduit model (SWMM) to simulate highly variable flow in a folded alpine karst aquifer system, where the underground drainage pattern is comparatively well-known from previous tracer studies. The conduit model was coupled with a reservoir model representing recharge, storage and transfer of water in the epikarst and unsaturated zone. The global optimization approach (GA) was applied to achieve an efficient model calibration. It was possible to simultaneously simulate the highly variable discharge characteristics of an estavelle, and overflow spring and a permanent spring draining the conduit system. The model allowed for the collection of spatially differentiated information on recharge, rapid flow and slow flow in four individual sub-catchments. The formation of backwater upgradient from conduit restrictions turned out to be a key process in activating overflow springs. The proposed modeling approach appears to be transferrable to other karst systems with predominant conduit drainage, but requires previous knowledge of the configuration of the conduit system.

  3. Nerve regeneration in chitosan conduits and in autologous nerve grafts in healthy and in type 2 diabetic Goto-Kakizaki rats.

    Science.gov (United States)

    Stenberg, Lena; Kodama, Akira; Lindwall-Blom, Charlotta; Dahlin, Lars B

    2016-02-01

    Knowledge about nerve regeneration after nerve injury and reconstruction in appropriate diabetic animal models is incomplete. Short-term nerve regeneration after reconstruction of a 10-mm sciatic nerve defect with either a hollow chitosan conduit or an autologous nerve graft was investigated in healthy Wistar and diabetic Goto-Kakizaki (GK) rats. After 21 days, axonal outgrowth, the presence of activated and apoptotic Schwann cells and the thickness of the formed matrix in the conduits were measured. In general, nerve regeneration was superior in autologous nerve grafts. In chitosan conduits, a matrix, which was thicker in diabetic rats, was formed and was positively correlated with length of axonal outgrowth. Axonal outgrowth in conduits and in nerve grafts extended further in diabetic rats than in healthy rats. There was a higher percentage of activating transcription factor 3 (ATF3)-immunostained cells in nerve segments from healthy rats than in diabetic rats after autologous nerve graft reconstruction. In chitosan conduits, more cleaved caspase 3-stained Schwann cells were generally observed in the matrix from the diabetic rats than in healthy rats. However, there were fewer apoptotic cells in the distal segment in diabetic rats reconstructed with a chitosan conduit. Preoperative glucose levels were positively correlated with axonal outgrowth after both reconstruction methods. Axonal regeneration was better in autologous nerve grafts than in hollow chitosan conduits and was enhanced in diabetic GK rats compared to healthy rats after reconstruction. This study provides insights into the nerve regeneration process in a clinically relevant diabetic animal model. PMID:26355640

  4. Simple Chemical Vapor Deposition Experiment

    Science.gov (United States)

    Pedersen, Henrik

    2014-01-01

    Chemical vapor deposition (CVD) is a process commonly used for the synthesis of thin films for several important technological applications, for example, microelectronics, hard coatings, and smart windows. Unfortunately, the complexity and prohibitive cost of CVD equipment makes it seldom available for undergraduate chemistry students. Here, a…

  5. HEDL sodium vapor deposit experience

    International Nuclear Information System (INIS)

    Sodium vapor deposits can affect reactor component operation and maintenance. Recorded cases include plugged cover gas lines and cementation of rotating components or sliding surfaces. Deposits found on plant scale components after testing in sodium were measured. Laboratory tests show the effect of Na pool temperature and condenser geometry on deposit accumulation rates and viewport fogging

  6. Water vapor measurements in- and outside cirrus with the novel water vapor mass spectrometer AIMS-H2O

    Science.gov (United States)

    Kaufmann, Stefan; Schlage, Romy; Voigt, Christiane; Jurkat, Tina; Krämer, Martina; Rolf, Christian; Zöger, Martin; Schäfler, Andreas; Dörnbrack, Andreas

    2015-04-01

    Water vapor plays a crucial role for the earth's climate both directly via its radiative properties and indirectly due to its ability to form clouds. However, accurate measurements of especially low water vapor concentrations prevalent in the upper troposphere and lower stratosphere are difficult and exhibit large discrepancies between different instruments and methods. In order to address this issue and to provide a comprehensive water vapor data set necessary to gather a complete picture of cloud formation processes, four state-of-the-art hygrometers including the novel water vapor mass spectrometer AIMS-H2O were deployed on the DLR research aircraft HALO during the ML-Cirrus campaign in March/April 2014 over Europe. Here, we present first water vapor measurements of AIMS-H2O on HALO. The instrument performance is validated by intercomparison with the fluorescence hygrometer FISH and the laser hygrometer SHARC, both also mounted in the aircraft. This intercomparison shows good agreement between the instruments from low stratospheric mixing ratios up to higher H2O concentrations at upper tropospheric conditions. Gathering data from over 24 flight hours, no significant offsets between the instruments were found (mean of relative deviation

  7. Formaldehyde emitted by chemical vapor sterilizers.

    Science.gov (United States)

    Cooley, R L; Stilley, J; Lubow, R M

    1984-01-01

    Formaldehyde has been identified as a potential occupational carcinogen and is a component of chemical solutions used in chemical vapor sterilizers. This study evaluated room air for formaldehyde in rooms where chemical vapor sterilizers were in use. PMID:6582430

  8. The effects of fenoldopam on coronary conduit blood flow after coronary artery bypass graft surgery.

    LENUS (Irish Health Repository)

    Halpenny, M

    2012-02-03

    OBJECTIVE: To quantify the effects of fenoldopam, 0.1 microg\\/kg\\/min, on left internal mammary artery (LIMA) and saphenous vein blood flow after coronary anastomosis. DESIGN: Prospective, randomized, double-blind, placebo-controlled trial. SETTING: University teaching hospital, single institution. PARTICIPANTS: Thirty-one American Society of Anesthesiologists III patients undergoing elective coronary revascularization. INTERVENTIONS: A perivascular ultrasonic flow probe (Linton Instrumentation, Norfolk, UK) was placed around the LIMA and saphenous vein graft after coronary anastomosis. MEASUREMENTS AND MAIN RESULTS: Immediately before and at 5-minute intervals for 15 minutes after starting the infusion, blood flow was measured in the LIMA and one saphenous vein graft using a transit time ultrasonic flow probe. Heart rate, blood pressure, and central venous pressure were documented at these time points. Administration of fenoldopam, 0.1 microg\\/kg\\/min, did not alter heart rate or blood pressure. A small, nonsignificant increase in LIMA blood flow occurred during the 15-minute study period (30 +\\/- 12 to 35 +\\/- 10 mL\\/min) in patients who received fenoldopam. No significant changes occurred in the placebo group. CONCLUSIONS: The findings indicate that fenoldopam, 0.1 microg\\/kg\\/min, did not influence coronary conduit blood flow to a clinically significant extent. The small increase in LIMA blood flow may be of greater importance in high-risk patients or in the prevention of coronary arterial spasm.

  9. "Pit Craters", lava tubes, and open vertical volcanic conduits in Hawaii: a problem in terminology

    Directory of Open Access Journals (Sweden)

    William R. Halliday

    1998-01-01

    Full Text Available Almost from the 1849 publication of the term pit crater, volcanologists have disagreed about the parameters differentiating these features from other vertical volcanic structures. Kaluaiki is a jameo giving entry to Thurston Lava Tube in Hawaii Volcanoes National Park. Long-standing misidentification of it as a pit crater is an example of misunderstandings arising from the lack of a clear definition of pit crater. In general, pit craters are unrelated to lava tube caves genetically, but two special cases are discussed. One probably is genetically related to a rift tube deep below the surface; the other is a complex of a small pit crater with a partial rim of accreted plates plus an ordinary-seeming lava tube cave. The term pit crater should be redefined in such a way that it excludes collapses or subsidences related to ordinary superficial lava tubes and open vertical volcanic conduits. Otherwise, a non-definition like that currently listed for agglomerate may be appropriate.

  10. Reverse saphenous conduit flap in small animals: Clinical applications and outcomes

    Scientific Electronic Library Online (English)

    Ross C., Elliott.

    2014-01-01

    Full Text Available Due to the lack of skin elasticity defects of the distal hind limb can be a challenge to close. This article assesses a well-described, but completely under-used technique for closure of wounds on the distal tarsus. The technique was used with good success in six cases presenting to the Bryanston Ve [...] terinary Hospital with a wide range of underlying pathology ranging from trauma to neoplastic disease of the tarsus. All six cases were treated with a reverse saphenous conduit flap and two of them underwent radiation therapy with no adverse side effects. All cases showed excellent results with a very low degree of flap necrosis that never exceeded 15% of the total flap area. This skin flap provides an excellent treatment method that is reliable in closure of defects of the distal tarsus with few adverse effects. To the author's knowledge there has been only one previously published report on the clinical use of this type of skin flap, even though the flap is well described in most texts.

  11. Joining of cable-in-conduit conductors in large superconducting magnet

    International Nuclear Information System (INIS)

    Joints between the conductors and terminals have always a very sensitive issue in superconducting magnets. The joints should have mechanically robust structure, low DC resistance and low AC losses not to be the weak links of the coils. They are also easy to prepare and assemble to reduce the manufacturing risk with well defined effective quality control steps. In the past, the research of joints was carried out to reduce the DC resistance for the DC operated magnets. Recently, many joints may be located in a high field and high field change rate region where is more severe environment than the conductor, because the magnets such as fusion magnets have complicated configurations and operated in the pulse mode. Optimal designs are needed to reduce the heat generation in the joint by considering the both of DC resistance and AC losses. In this report, the design criteria of the joints for cable-in-conduit conductors are defined. The properties and needed manufacturing techniques of some joints such as lap joint, strand-to-strand joint, and butt joint are explained. To verify the characteristics of each joint, the operating conditions and coil structures of the large scale magnets for fusion, which were built or are being built, are introduce. The DC resistance and AC losses of the joints are compared and their manufacturing method are introduced

  12. Fabrication of cable in conduit conductors at europa metalli-LMI

    International Nuclear Information System (INIS)

    Since the middle of the seventies the CIC (Cable In Conduit) conductor configuration has attracted much interest for fusion reactor magnets (1). In recent years the CIC solution has been proposed and tested for poloidal coils, operated in pulsed fields; in the latter case the maximization of the cooled superconductor perimeter achieved by the CIC design appears the obligatory choice to minimize a.c. losses. Quite recently the CIC configuration has been proposed for winding MHD magnets and SMES devices, both with a stainless steel jacket and with an age-hardenable Al alloy jacket (2;3). Fabrication procedures for CIC conductors have been developed at EM-LMI on cable prototypes and are now being implemented for long length conductors. For high field conductors, based on Nb3Sn, austenitic stainless steel (or better, Incolloy) appears the most suitable material for the jacket, due to its capability to withstand the high temperature (?700 C) treatment needed to form the superconducting compound. For medium field applications, where Nb-Ti is the suitable superconductor, age-hardenable Al alloys are by far the most convenient material, due to the availability of continuous Al alloy tubes of any selected geometry and length, and to their unique feature of offering ''flexible'' mechanical properties, from soft to hard. The present paper reports the status achieved at EM-LMI in manufacturing CIC conductors and an overview of the lay-out and the manufacturing of four CIC conductors which have been assigned to EM-LMI. (orig.)

  13. Trees are important conduits for emission of methane from temperate and tropical wetlands

    Science.gov (United States)

    Gauci, Vincent; Pangala, Sunitha; Gowing, David; Hornibrook, Edward

    2013-04-01

    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 conduit 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 controlled 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.

  14. A new cable-in-conduit conductor magnet with insulated strands

    International Nuclear Information System (INIS)

    Many studies have used cable-in-conduit conductor (CICC) coils in trying to develop an AC superconducting magnet because of its enormous potential if AC losses were low and insulation voltage was high. The strands in the most recent CICC magnets are coated with chromium or another metal with high electrical resistance to order to induce current re-distribution among the strands and to avoid a quench caused by a current imbalance. Current re-distribution is highly complex and very difficult to analyze because the conditions of the strand surfaces and the contact areas vary greatly with the operation of the conductor. If, however, the cable currents were well-balanced, insulating the strands would be the best way to reduce AC losses. We propose a new CICC magnet structure featuring a current lead that balances the strand currents via its resistance. Having calculated current balances, we find that strand currents are well within the present parameters for nuclear fusion experiments and superconducting magnet energy storages. (author)

  15. Three dimensional CFD analysis of Cable-in-Conduit Conductors (CICCs) using porous medium approach

    Science.gov (United States)

    Raja Sekhar, Dondapati; Rao, V. V.

    2013-02-01

    Thermohydraulic studies based on porous medium analogy, pertinent to dual channel Cable-in-Conduit Conductors (CICCs) used in International Thermonuclear Experimental Reactor (ITER), are explored in the present work. Dual channel CICC used in Toroidal Field (TF) Coil consists of a circular jacket in which superconducting cable bundles are placed in the annular channel separated from the central channel by a spiral. The cable bundle in the annular channel can be considered as saturated porous medium and the central channel can be viewed as clear region for thermohydraulic studies. In the present work, a 3D Computational Fluid Dynamics (CFD) analysis is performed on CICC by considering dual channel CICC as partially filled saturated porous medium. The 3D geometry was developed and meshed in GAMBIT-2.1.6, and exported to a commercial solver FLUENT -6.3.26 for further analysis. The effect of mass flow rate ( 6 - 10 g/s) of supercritical helium (SHe) on the velocity and pressure gradient distributions (axial and radial) in the transverse plane is presented. These studies resulted in estimating the mass flow repartition between the two channels and pumping power required to pump the SHe in CICC. In addition, the present CFD analysis brings a clear perspective of the phenomena of flow and heat transfer in complex geometries such as CICC.

  16. Normal zone propagation and Thermal Hydraulic Quenchback in a cable-in-conduit superconductor

    International Nuclear Information System (INIS)

    When a local normal zone appears in a cable-in-conduit superconductor, a slug of hot helium is produced. The pressure rises and the hot helium expands. Thus the normal zone propagation in such a conductor can be governed by the hot helium expansion, rather than the heat conduction along the conductor. The expansion of the hot helium compresses the cold helium outside of the normal zone. This raises th at sign temperature of the cold helium. When the temperature rise reaches the current sharing limit, the superconductor in contact goes normal. Thus a rapid increase in normal zone propagation occur. This phenomenon is termed Thermal Hydraulic Quenchback (THQ). An experiment was performed to investigate this process. The existence of THQ was verified. Thresholds of THQ were also observed by varying the conductor current, the magnetic field, the temperature, and the initial normal zone length. When THQ occurred, normal zone propagation approaching the velocity of sound was observed. A better picture of THQ is obtained by a careful comparison of the data with analytical studies

  17. Thermo-Hydraulic behaviour of dual-channel superconducting Cable-In-Conduit Conductors for ITER

    International Nuclear Information System (INIS)

    In an effort to optimise the cryogenics of large superconducting coils for fusion applications (ITER), dual channel Cable-In-Conduit Conductors (CICC) are designed with a central channel spiral to provide low hydraulic resistance and faster helium circulation. The qualitative and economic rationale of the conductor central channel is here justified to limit the superconductor temperature increase, but brings more complexity to the conductor cooling characteristics. The pressure drop of spirals is experimentally evaluated in nitrogen and water and an explicit hydraulic friction model is proposed. Temperatures in the cable must be quantified to guarantee superconductor margin during coil operation under heat disturbance and set adequate inlet temperature. Analytical one-dimensional thermal models, in steady state and in transient, allow to better understand the thermal coupling of CICC central and annular channels. The measurement of a heat transfer characteristic space and time constants provides cross-checking experimental estimations of the internal thermal homogenization. A simple explicit model of global inter-channel heat exchange coefficient is proposed. The risk of thermosyphon between the two channels is considered since vertical portions of fusion coils are subject to gravity. The new hydraulic model, heat exchange model and gravitational risk ratio allow the thermohydraulic improvement of CICC central spirals. (author)

  18. The Medial Temporal Lobe – Conduit of Parallel Connectivity: A model for Attention, Memory, and Perception.

    Directory of Open Access Journals (Sweden)

    Brian B. Mozaffari

    2014-11-01

    Full Text Available Based on the notion that the brain is equipped with a hierarchical organization, which embodies environmental contingencies across many time scales, this paper suggests that the medial temporal lobe (MTL – located deep in the hierarchy – serves as a bridge connecting supra to infra – MTL levels. Bridging the upper and lower regions of the hierarchy provides a parallel architecture that optimizes information flow between upper and lower regions to aid attention, encoding, and processing of quick complex visual phenomenon. Bypassing intermediate hierarchy levels, information conveyed through the MTL ‘bridge’ allows upper levels to make educated predictions about the prevailing context and accordingly select lower representations to increase the efficiency of predictive coding throughout the hierarchy. This selection or activation/deactivation is associated with endogenous attention. In the event that these ‘bridge’ predictions are inaccurate, this architecture enables the rapid encoding of novel contingencies. A review of hierarchical models in relation to memory is provided along with a new theory, Medial-temporal-lobe Conduit for Parallel Connectivity (MCPC. In this scheme, consolidation is considered as a secondary process, occurring after a MTL-bridged connection, which eventually allows upper and lower levels to access each other directly. With repeated reactivations, as contingencies become consolidated, less MTL activity is predicted. Finally, MTL bridging may aid processing transient but structured perceptual events, by allowing communication between upper and lower levels without calling on intermediate levels of representation.

  19. FEMCAM Analysis of SULTAN Test Results for ITER Nb3SN Cable-conduit Conductors

    Energy Technology Data Exchange (ETDEWEB)

    Yuhu Zhai, Pierluigi Bruzzone, Ciro Calzolaio

    2013-03-19

    Performance degradation due to filament fracture of Nb3 Sn cable-in-conduit conductors (CICCs) is a critical issue in large-scale magnet designs such as ITER which is currently being constructed in the South of France. The critical current observed in most SULTAN TF CICC samples is significantly lower than expected and the voltage-current characteristic is seen to have a much broader transition from a single strand to the CICC. Moreover, most conductors exhibit the irreversible degradation due to filament fracture and strain relaxation under electromagnetic cyclic loading. With recent success in monitoring thermal strain distribution and its evolution under the electromagnetic cyclic loading from in situ measurement of critical temperature, we apply FEMCAM which includes strand filament breakage and local current sharing effects to SULTAN tested CICCs to study Nb3 Sn strain sensitivity and irreversible performance degradation. FEMCAM combines the thermal bending effect during cool down and the EM bending effect due to locally accumulating Lorentz force during magnet operation. It also includes strand filament fracture and related local current sharing for the calculation of cable n value. In this paper, we model continuous performance degradation under EM cyclic loading based on strain relaxation and the transition broadening upon cyclic loading to the extreme cases seen in SULTAN test data to better quantify conductor performance degradation.

  20. Diverse types of epineural conduits for bridging short nerve defects. An experimental study in the rabbit.

    Science.gov (United States)

    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

    2007-01-01

    In this study the process of peripheral nerve regeneration through an epineural flap conduit was examined using four groups of 126 New Zealand rabbits. There were three study groups (A, B, and C) and 1 control 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 control 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. PMID:17290376

  1. Droplet sizes and velocities in vaporizing sprays

    Energy Technology Data Exchange (ETDEWEB)

    Yule, A.J.; Ereaut, P.R.; Ungut, A.

    1983-12-01

    A pulse height laser Doppler anemometer particle sizing technique has been refined to permit simultaneous particle size and velocity measurements in sprays. The improvements include (1) the use of a specially tailored 'top hat' light distribution, to provide unambiguous particle diameter-signal amplitude relations, (2) the use of back scattered light collection, and (3) the utilization of Mie theory to compute the relations between signal amplitude and particle diameter, in the backscatter mode. Twin-fluid atomized kerosene sprays have been investigated using the new technique. In these sprays distributions have been mapped of mean droplet diameters, droplet size distributions, and the local correlations between droplet diameters and velocities. The data show the variation of spray structure with atomizer input parameters, the preferential vaporization of smaller droplets, and the differing trajectories of the large and small droplets. 6 references.

  2. Hanford soil partitioning and vapor extraction study

    International Nuclear Information System (INIS)

    This report describes the testing and results of laboratory experiments conducted to assist the carbon tetrachloride soil vapor extraction project operating in the 200 West Area of the Hanford Site in Richland, Washington. Vapor-phase adsorption and desorption testing was performed using carbon tetrachloride and Hanford Site soils to estimate vapor-soil partitioning and reasonably achievable carbon tetrachloride soil concentrations during active vapor extractions efforts at the 200 West Area. (CCl4 is used in Pu recovery from aqueous streams.)

  3. Low temperature operated copper vapor laser

    International Nuclear Information System (INIS)

    Experimental studies on newly developed copper vapor laser operated in hydrogen bromide gas under low temperature were successfully achieved using a conventional high temperature operated copper vapor laser tube. We present remarkable difference against conventional copper vapor laser in terms of the spatial and temporal features. This type of copper vapor laser is expected to have higher efficiency at high pulse repetition frequency and advantage in the features of laser pulse. (author)

  4. Experimental results of 40-kA Nb3Al cable-in-conduit conductor for fusion machines

    Science.gov (United States)

    Takahashi, Y.; Sugimoto, M.; Isono, T.; Nakajima, H.; Ando, T.; Oshikiri, M.; Hosono, F.; Wadayama, Y.; Sasaki, T.; Hanawa, H.

    1994-07-01

    A 40-kA Nb3Al cable-in-conduit conductor has been developed for the toroidal field coils of fusion reactors, because Nb3Al has excellent mechanical performance. This conductor consists of 405 copper-stabilized multifilamentary strands inserted into a CuNi circular conduit. The Nb3Al strands are fabricated by the Jelly-roll process with a diameter of 1.22 mm. This conductor could be operated up to a current of 46 kA at an external field of 11.2 T. Accordingly, Nb3Al promises to soon become a useful superconductor for large-scale high-field applications, such as fusion machines.

  5. Ic analysis of Nb3Sn strand cable-in-conduit conductor under the electromagnetic force by the structural mechanics

    International Nuclear Information System (INIS)

    The Cable-In-Conduit Conductor (CICC) is the most promising one for large scale fusion magnets. Now it has been adopted as conductors for ITER magnets. Although the conductor has good mechanical strength against large electromagnetic force, the performance is not so good because the Nb3Sn strands are fragile and the critical current density is sensitive to strain. Because the conductor is composed of hundreds or thousands of strands which are twisted and become tangled, the strands experience extra-bending during energizing magnets. It seems so difficult to analyze plastic deformation of the strands of whole conductor. Our approach to calculate it is unique in terms of using structural mechanics called 'Beam Model' based on the measured strand traces inside the conduit. The calculated traces provide us the local curvatures of strands under electromagnetic force. This leads to the evaluate the conductor performance such as Ic degradation. (author)

  6. Effect of chrome plating on coupling losses in a Nb3Sn cable-in-conduit conductor

    International Nuclear Information System (INIS)

    Time constant of decay of coupling current was measured on cable-in-conduit conductors which consist of twelve Nb3Sn strands with chrome plating. The time constant measurement was performed by observing exponential decrease of induced coupling current in conductors. The measured time constant of conductor composed of bare strands was 4.5 times larger than that of the single strand, in case that a void fraction of conductor was 30%. However, the time constant of conductor composed of strands with chrome plating of more than 2 ?m thickness was equal to that of the single strand. These results show that chrome plating on strands is effective for decrease of coupling losses in Nb3Sn cable-in-conduit conductors. (author)

  7. Preparation Of Sources For Plasma Vapor Deposition

    Science.gov (United States)

    Waters, William J.; Sliney, Hal; Kowalski, D.

    1993-01-01

    Multicomponent metal targets serving as sources of vapor for plasma vapor deposition made in modified pressureless-sintering process. By use of targets made in modified process, one coats components with materials previously plasma-sprayed or sintered but not plasma-vapor-deposited.

  8. Observateurs d'état pour le diagnostic de comportement dynamique de véhicules automobiles en environnement réel de conduite

    OpenAIRE

    Wang, Bin

    2013-01-01

    Le contrôle de stabilité est un sujet essentiel dans les systèmes avancés d'aide à la conduite développés par les constructeurs et équipementiers automobiles. Les systèmes de sécurité actifs sont devenus un standard dans les véhicules particuliers, tels que : le contrôle électronique de la stabilité (ESC) et le système de contrôle de traction (TCS). La description du comportement dynamique du véhicule pendant le mouvement, est fondamental dans le fonctionnement des nouveaux systèmes de sécuri...

  9. Spatial analysis of karst conduit networks and determination of parameters controlling the speleogenesis along preferential lithostratigraphic horizons

    OpenAIRE

    Filipponi, Marco

    2009-01-01

    The main objective of this thesis is to improve the understanding of the position and characteristics of karst conduits within a rock massif. Such a characterisation is an important issue in civil engineering and in hydrogeology. Today in practice dissolution voids are considered as random in most cases. However, it is obvious for karst researchers that dissolution void distribution is not random, but defined by parameters controlling the speleogenesis. We developed a method to analyse the 3D...

  10. Speleogenetic effects of interaction between deeply derived fracture-conduit flow and intrastratal matrix flow in hypogene karst settings

    OpenAIRE

    Tymokhina Elizaveta; Amelichev Gennadiy; Klimchouk Alexander

    2012-01-01

    In carbonate rocks, especially in those with high primary porosity such as most Cenozoic carbonates, the interaction between deeply derived rising flow through sub-vertical fracture-controlled conduits and intrastratal matrix flow of shallower systems can invoke mixing cor- rosion and result in prominent speleogenetic effects. This paper outlines a conceptual model of such interaction and provides instructive field examples of relevant morphological effects from two different regions within t...

  11. Laboratory and numerical study of hyporheic flow in karst conduits and its effect on sediment-entrapped DNAPLs

    OpenAIRE

    Wu, Yuexia; Hunkeler, Daniel

    2013-01-01

    Contamination of karst aquifer, particularly by organic compounds, such as the Dense Non-aqueous Phase Liquids (DNAPLs) constitutes a threat for water supply and the environment. Due to the presence of large openings in karst systems and the high density of DNAPLs they may frequently reach conduits and accumulate at low points such as siphon structures that likely also contain sediments. Hence sediment-entrapped DNAPLs are commonly encountered and present as a continuous phase of organic liqu...

  12. Nitric oxide permits hypoxia-induced lymphatic perfusion by controlling arterial-lymphatic conduits in zebrafish and glass catfish

    DEFF Research Database (Denmark)

    Dahl Ejby Jensen, Lasse; Cao, Renhai; Hedlund, Eva-Maria; Söll, Iris; Lundberg, Jon O; Hauptmann, Giselbert; Steffensen, John Fleng; Cao, Yihai

    2009-01-01

    The blood and lymphatic vasculatures are structurally and functionally coupled in controlling tissue perfusion, extracellular interstitial fluids, and immune surveillance. Little is known, however, about the molecular mechanisms that underlie the regulation of bloodlymphatic vessel connections and lymphatic perfusion. Here we show in the adult zebrafish and glass catfish (Kryptopterus bicirrhis) that blood-lymphatic conduits directly connect arterial vessels to the lymphatic system. Under hypoxi...

  13. Nitric oxide permits hypoxia-induced lymphatic perfusion by controlling arterial-lymphatic conduits in zebrafish and glass catfish

    OpenAIRE

    Dahl Ejby Jensen, Lasse; Cao, Renhai; Hedlund, Eva-Maria; Söll, Iris; Lundberg, Jon O.; Hauptmann, Giselbert; Steffensen, John Fleng; Cao, Yihai.

    2009-01-01

    The blood and lymphatic vasculatures are structurally and functionally coupled in controlling tissue perfusion, extracellular interstitial fluids, and immune surveillance. Little is known, however, about the molecular mechanisms that underlie the regulation of bloodlymphatic vessel connections and lymphatic perfusion. Here we show in the adult zebrafish and glass catfish (Kryptopterus bicirrhis) that blood-lymphatic conduits directly connect arterial vessels to the lymphatic system. Under hyp...

  14. The overwhelming use of rat models in nerve regeneration research may compromise designs of nerve guidance conduits for humans

    OpenAIRE

    Kaplan, Hilton M.; Mishra, Prakhar; Kohn, Joachim

    2015-01-01

    Rats are not the best model for the evolving complexities we face in designing nerve repair strategies today. The development of effective nerve guidance conduits for nerve regeneration is severely limited by the rat sciatic nerve model as the almost exclusive research model in academia. An immense effort is underway to develop an alternative to autologous nerve grafts for the repair of nerve defects, aiming particularly at larger gap repairs of 5–30 cm or more. This must involve combinations...

  15. Effect of Strand Longitudinal Thermal Conduction on Take-Off Properties of Cable-in-Conduit Superconductors

    OpenAIRE

    A.Anghel

    2004-01-01

    The effect of the strand longitudinal thermal conduction carried mainly by the stabilizing copper on the take-off (quench) behaviour of cable-in-conduit supercondutors is investigated theoretically and numerically. An equal area criterion type of condition is found for the thermal equilibrium of the conductor. It is shown that the thermal conduction effect can be quantified in terms of an effective, enhanced heat-exchange coefficient.

  16. The influence of conduit processes on changes in style of basaltic Plinian eruptions: Tarawera 1886 and Etna 122 BC

    OpenAIRE

    Houghton, B. F.; Department of Geology and Geophysics, University of Hawaii, Honolulu, HI 96822, USA; Wilson, C. J. N.; Institute of Geological and Nuclear Sciences, Taupo, New Zealand; Del Carlo, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Coltelli, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Sable, J. E.; Department of Geology and Geophysics, University of Hawaii, Honolulu, HI 96822, USA; Carey, R.; CODES, University of Tasmania, Hobart , Australia

    2004-01-01

    Basaltic volcanism is most typically thought to produce effusion of lava, with the most explosive manifestations ranging from mild Strombolian activity to more energetic fire fountain eruptions. However, some basaltic eruptions are now recognized as extremely violent, i.e., generating widespread phreatomagmatic, subplinian and Plinian fall deposits. We focus here on the influence of conduit processes, especially partial open-system degassing, in triggering abrupt changes in style and intensit...

  17. Conduit Companies, Beneficial Ownership, and the Test of Substantive Business Activity in Claims for Relief under Double Tax Treaties

    OpenAIRE

    Jain, Saurabh; Prebble, John; Bunting, Christina

    2014-01-01

    If interpreted in a strict legal sense, beneficial ownership rules in tax treaties would have no effect on conduit companies because companies at law own their property and income beneficially. Conversely, a company can never own anything in a substantive sense because economically a company is no more than a congeries of arrangements that represents the people behind it. Faced with these contradictory considerations, people have adopted surrogate tests that they attempt to employ in...

  18. Absorption of tritiated water vapor from the atmosphere by the needles of pine trees

    International Nuclear Information System (INIS)

    One means of tritium absorption into an ecosystem is the diffusion of tritiated water vapor into tree needles where it becomes part of the plant water supply. The mechanisms by which absorption of tritiated water vapor takes place were studied with two slash pine trees: Pinus elliotii Engelm. Three branches on each tree were enclosed in clear plastic bags, and three branches on each tree were enclosed in double, dark green bags. Forty ml of water containing 15.7 nCi/ml of tritium were placed in the bottom of each bag. The foliage was not exposed directly to the water, so that all absorption would take place in the vapor phase. An analysis of the uptake rates indicates that tritiated water vapor diffuses into the foliage by the same pathways as water vapor diffuses out of the foliage and rapidly becomes mixed with the bulk of the leaf water

  19. Modeling upper tropospheric and lower stratospheric water vapor anomalies

    Directory of Open Access Journals (Sweden)

    M. R. Schoeberl

    2013-08-01

    Full Text Available The domain-filling, forward trajectory calculation model developed by Schoeberl and Dessler (2011 is used to further investigate processes that produce upper tropospheric and lower stratospheric water vapor anomalies. We examine the pathways parcels take from the base of the tropical tropopause layer (TTL to the lower stratosphere. Most parcels found in the lower stratosphere arise from East Asia, the Tropical West Pacific (TWP and Central/South America. The belt of TTL parcel origins is very wide compared to the final dehydration zones near the top of the TTL. This is due to the convergence of rising air due to the stronger diabatic heating near the tropopause relative to levels above and below. The observed water vapor anomalies – both wet and dry – correspond to regions where parcels have minimal displacement from their initialization. These minimum displacement regions include the winter TWP and the Asian and American monsoons. To better understand the stratospheric water vapor concentration we introduce the water vapor spectrum and investigate the source of the wettest and driest components of the spectrum. We find that the driest air parcels originate below the TWP, moving upward to dehydrate in the TWP cold upper troposphere. The wettest air parcels originate at the edges of the TWP as well as in the summer American and Asian monsoons. The wet air parcels are important since they skew the mean stratospheric water vapor distribution toward higher values. Both TWP cold temperatures that produce dry parcels as well as extra-TWP processes that control the wet parcels determine stratospheric water vapor.

  20. Modeling upper tropospheric and lower stratospheric water vapor anomalies

    Directory of Open Access Journals (Sweden)

    M. R. Schoeberl

    2013-04-01

    Full Text Available The domain-filling, forward trajectory calculation model developed by Schoeberl and Dessler (2011 is used to further investigate processes that produce upper tropospheric and lower stratospheric water vapor anomalies. We examine the pathways parcels take from the base of the tropical tropopause layer (TTL to the lower stratosphere. Most parcels found in the lower stratosphere arise from East Asia, the Tropical West Pacific (TWP and the Central/South America. The belt of TTL parcel origins is very wide compared to the final dehydration zones near the top of the TTL. This is due to the convergence of rising air as a result of the stronger diabatic heating near the tropopause relative to levels above and below. The observed water vapor anomalies – both wet and dry – correspond to regions where parcels have minimal displacement from their initialization. These minimum displacement regions include the winter TWP and the Asian and American monsoons. To better understand the stratospheric water vapor concentration we introduce the water vapor spectrum and investigate the source of the wettest and driest components of the spectrum. We find that the driest air parcels that originate below the TWP, moving upward to dehydrate in the TWP cold upper troposphere. The wettest air parcels originate at the edges of the TWP as well as the summer American and Asian monsoons. The wet air parcels are important since they skew the mean stratospheric water vapor distribution toward higher values. Both TWP cold temperatures that produce dry parcels as well as extra-TWP processes that control the wet parcels determine stratospheric water vapor.

  1. Liquid-phase compositions from vapor-phase analyses

    Energy Technology Data Exchange (ETDEWEB)

    Davis, W. Jr. (Oak Ridge Gaseous Diffusion Plant, TN (USA)); Cochran, H.D. (Oak Ridge National Lab., TN (USA))

    1990-02-01

    Arsenic normally is not considered to be a contaminant. However, because arsenic was found in many cylinders of UF{sub 6}, including in corrosion products, a study was performed of the distribution of the two arsenic fluorides, AsF{sub 3} and AsF{sub 5}, between liquid and vapor phases. The results of the study pertain to condensation or vaporization of liquid UF{sub 6}. This study includes use of various experimental data plus many extrapolations necessitated by the meagerness of the experimental data. The results of this study provide additional support for the vapor-liquid equilibrium model of J.M. Prausnitz and his coworkers as a means of describing the distribution of various impurities between vapor and liquid phases of UF{sub 6}. Thus, it is concluded that AsF{sub 3} will tend to concentrate in the liquid phase but that the concentration of AsF{sub 5} in the vapor phase will exceed its liquid-phase concentration by a factor of about 7.5, which is in agreement with experimental data. Because the weight of the liquid phase in a condensation operation may be in the range of thousands of times that of the vapor phase, most of any AsF{sub 5} will be in the liquid phase in spite of this separation factor of 7.5. It may also be concluded that any arsenic fluorides fed into a uranium isotope separation plant will either travel with other low-molecular-weight gases or react with materials present in the plant. 25 refs., 3 figs., 6 tabs.

  2. Active Hydrazine Vapor Sampler (AHVS)

    Science.gov (United States)

    Young, Rebecca C.; Mcbrearty, Charles F.; Curran, Daniel J.

    1993-01-01

    The Active Hydrazine Vapor Sampler (AHVS) was developed to detect vapors of hydrazine (HZ) and monomethylhydrazine (MMH) in air at parts-per-billion (ppb) concentration levels. The sampler consists of a commercial personal pump that draws ambient air through paper tape treated with vanillin (4-hydroxy-3-methoxybenzaldehyde). The paper tape is sandwiched in a thin cardboard housing inserted in one of the two specially designed holders to facilitate sampling. Contaminated air reacts with vanillin to develop a yellow color. The density of the color is proportional to the concentration of HZ or MMH. The AHVS can detect 10 ppb in less than 5 minutes. The sampler is easy to use, low cost, and intrinsically safe and contains no toxic material. It is most beneficial for use in locations with no laboratory capabilities for instrumentation calibration. This paper reviews the development, laboratory test, and field test of the device.

  3. Vapor deposition of tantalum and tantalum compounds

    International Nuclear Information System (INIS)

    Tantalum, and many of its compounds, can be deposited as coatings with techniques ranging from pure, thermal chemical vapor deposition to pure physical vapor deposition. This review concentrates on chemical vapor deposition techniques. The paper takes a historical approach. The authors review classical, metal halide-based techniques and current techniques for tantalum chemical vapor deposition. The advantages and limitations of the techniques will be compared. The need for new lower temperature processes and hence new precursor chemicals will be examined and explained. In the last section, they add some speculation as to possible new, low-temperature precursors for tantalum chemical vapor deposition

  4. Molten salt vaporization during electrolytic reduction

    International Nuclear Information System (INIS)

    The suppression of molten salt vaporization is one of the key technical issues in the electrolytic reduction process developed for recycling spent nuclear fuel from light-water reactors Since the Hertz-Langmuir relation previously applied to molten salt vaporization is valid only for vaporization into a vacuum, a diffusion model was derived to quantitatively assess the vaporization of LiCl, Li2O and Li from an electrolytic reducer operating under atmospheric pressure. Vaporization rates as a function of operation variables were calculated and shown to be in reasonable agreement with the experimental data obtained from thermogravimetry

  5. High temperature vapors science and technology

    CERN Document Server

    Hastie, John

    2012-01-01

    High Temperature Vapors: Science and Technology focuses on the relationship of the basic science of high-temperature vapors to some areas of discernible practical importance in modern science and technology. The major high-temperature problem areas selected for discussion include chemical vapor transport and deposition; the vapor phase aspects of corrosion, combustion, and energy systems; and extraterrestrial high-temperature species. This book is comprised of seven chapters and begins with an introduction to the nature of the high-temperature vapor state, the scope and literature of high-temp

  6. What Good is Raman Water Vapor Lidar?

    Science.gov (United States)

    Whitman, David

    2011-01-01

    Raman lidar has been used to quantify water vapor in the atmosphere for various scientific studies including mesoscale meteorology and satellite validation. Now the international networks of NDACC and GRUAN have interest in using Raman water vapor lidar for detecting trends in atmospheric water vapor concentrations. What are the data needs for addressing these very different measurement challenges. We will review briefly the scientific needs for water vapor accuracy for each of these three applications and attempt to translate that into performance specifications for Raman lidar in an effort to address the question in the title of "What good is Raman water vapor Iidar."

  7. Vapor fraction distribution within pipelines and channels

    International Nuclear Information System (INIS)

    Three-dimensional distribution of vapor volumetric fractions in subcooled boiling is analyzed for circular tubes and rectangular channels. The model is based on three major assumptions: 1) vapor bubble mation is controlled by diffusion due to flow turbulence; 2) the diffusion coefficient and bubble velocity are constant within the channel cross-section as well as the coolant temperature; 3) the vapor bubble generation and condensation rates are calculated according to one-dimensional models. The vapor void distribution is obtained from an analytical solution of the vapor bubble diffusion equation with a simplified approximation of subcooling profile. A method of boundary conditions formulation for the diffusin equation is also presented

  8. Water vapor diffusion membrane development

    Science.gov (United States)

    Tan, M. K.

    1977-01-01

    An application of the water vapor diffusion technique is examined whereby the permeated water vapor is vented to space vacuum to alleviate on-board waste storage and provide supplemental cooling. The work reported herein deals primarily with the vapor diffusion-heat rejection (VD-HR) as it applies to the Space Shuttle. A stack configuration was selected, designed and fabricated. An asymmetric cellulose acetate membrane, used in reverse osmosis application was selected and a special spacer was designed to enhance mixing and promote mass transfer. A skid-mount unit was assembled from components used in the bench unit although no attempt was made to render it flight-suitable. The operating conditions of the VD-HR were examined and defined and a 60-day continuous test was carried out. The membranes performed very well throughout the test; no membrane rupture and no unusual flux decay was observed. In addition, a tentative design for a flight-suitable VD-HR unit was made.

  9. Transcurrent Fault Systems in the Mojave Desert, Conduits or Barriers to Groundwater Flow?

    Science.gov (United States)

    Dailey, D. R.; Sultan, M.; Milewski, A.; Sauck, W.; Laton, R.; Foster, J. H.

    2010-12-01

    The Mojave Desert is characterized by a series of staggered, NW trending dextral strike-slip fault systems (e.g., Helendale, Lenwood) that formed as secondary systems to the San Andreas Fault. To investigate whether these faults are barriers or conduits (or both), an integrated (geophysics, remote sensing, field, subsurface modeling) study was conducted in the Mojave Basin: (1) the Helendale fault traces were mapped using geologic maps, false color images from ASTER VNIR bands, aerial photographs, and SRTM digital elevation data; (2) Geophysical transects (Very Low Frequency [VLF]; and magnetometer) were carried out across the Helendale fault. Eleven sites were surveyed with 14 transects in 3 days in 2009 and several were revisited again in 2010. Data acquired over the same transects were consistent in years 2009 and 2010. VLF measurements across the fault traces along the ridge flanks and upper alluvial fans showed significant radio field dip angles (up to 60% tilt) consistent with the presence of sub-vertical, sheet-like conductors in the shallow subsurface, whereas near the valley floor no appreciable VLF anomalies were seen probably because the water table was below the reach of the VLF (several 10’s of meters). For many of the acquired VLF tilt profiles, the peaks coincided with changes in the magnetic profiles that are to be expected across faults which juxtapose rocks with varying magnetic properties. One interpretation for our preliminary data sets is that the Helendale fault and most likely other dextral faults in the area are channeling groundwater from the surrounding mountains to the lowlands (Lucerne Valley). The faulted coarse-grained fanglomerates apparently provide higher hydraulic conductivity near the mountains. On the other hand, the distal silts, clays, and lacustrine deposits near the valley floor act as barriers to groundwater flow. Depending on its location in relation to the distribution of fan and lacustrine deposits, the fault zone can appear as a conduit or a barrier. Three cross sections and 6 subsurface 3-D lithologic models were generated from available well logs (469 wells) to investigate whether the observed differences in water levels across the Helendale fault are caused by: (1) differences in lithology and hydraulic properties of reservoir rock units across the fault or by (2) elevated bedrock occurrences along its length. On the NE side of the Helendale fault (Este sub-basin), thick units (average thickness: 120-150 m) of high hydraulic conductivities (average hydraulic conductivity: K= 25 m/day) were observed. In contrast, units of low conductivities (average thickness: 230 m; average hydraulic conductivity: K= 0.04 m/day) were reported on the SW side. Wells along the Helendale and gravity data did not reveal obvious bedrock barriers. Findings suggest that the Helendale fault, and most likely other dextral faults in the area, may be channeling groundwater from the surrounding mountains to the lowland and the observed differences in groundwater levels could be largely related to lateral variations in lithologic and hydraulic properties of aquifers across the faults.

  10. Three-layer microfibrous peripheral nerve guide conduit composed of elastin-laminin mimetic artificial protein and poly(L-lactic acid)

    OpenAIRE

    TetsujiYamaoka; MidoriNakayama

    2014-01-01

    We developed a microfibrous poly(L-lactic acid) (PLLA) nerve conduit with a three-layered structure to simultaneously enhance nerve regeneration and prevent adhesion of surrounding tissue. The inner layer was composed of PLLA microfiber containing 25% elastin-laminin mimetic protein (AG73-(VPGIG)30) that promotes neurite outgrowth. The thickest middle layer was constructed of pure PLLA microfibers that impart the large mechanical stremgth to the conduit. A 10% poly(ethylene glycol) was added...

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

    Science.gov (United States)

    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 geophysical method used. At some sites such as Pozo Brujo, the University of Puerto Rico Agricultural Experiment Station, and Monte Encantado area, natural potential anomalies strongly suggest the existence of conduits with flowing water. At most sites, however, the results obtained did not clearly reveal the presence of subsurface cavities that might be associated with the occurrence of conduit-controlled ground-water flow. Sites such as the University of Puerto Rico Agricultural Experiment Station, Pozo Brujo, and Quebrada de los Cedros warrant a more detailed analysis, including a test well drilling phase to confirm the presence of suspected high-yield water-bearing zones.

  12. Vaporization of In2Te3(s)

    International Nuclear Information System (INIS)

    The vaporization chemistry of In2Te3(s) was studied by the computerautomated simultaneous Knudsen-effusion and torsion-effusion method, by high-temperature mass spectrometry, and by ancillary methods. The first absolute measurements of the vapor pressure of In2Te3 are reported. In2Te3(s) vaporized incongruently in the temperatue range 701-889 K and produced Te2(g) and a solid-solution, (Xsub(In)=0.42 and Xsub(Te)=0.58). The standard enthalpy of the reaction at 298 K, ?H0 (298 K) by the third-law method was 136.0 +- 0.3 kJ/mol of vapor. The above solid solution vaporized incongruently and produced in InTe(s) and a vapor which consisted of Te2(g) and In2Te(g). InTe(s) vaporized congruently in the range 701-887 K and produded Te2(g) and In2Te(g); the third-law ?H0sub(?) (298 K) was 201.5 +- 1.0 kJ/mol. These results were at variance with the literature on vaporization of In2Te3(s) where both congruent vaporization and incongruent vaporization to give InTe(s) are separately reported. Further, InTe(s) was reported to vaporize incongruently. These differences are discussed. (Author)

  13. Thermal hydraulic characteristics study of prototype NET and CEA cable-in-conduit conductors (CICCs)

    Energy Technology Data Exchange (ETDEWEB)

    Maekawa, Ryuji

    1995-10-31

    The thermal hydraulic characteristics of low temperature helium in a Cable-in-Conduit Conductor (CICC) significantly affects the overall design and performance of the associated large scale superconducting magnet system. It is essential to understand the transient and steady state behavior of the helium in the conductor. Throughout the development of CICCs, the reduction of flow impedance has been one of the key factors to improving the overall pressure drop. The newly developed CICC for the ITER project has a hybrid cooling scheme: a central channel that is surrounded by bundles, for which the thermal hydraulic characteristics are not well understood. This thesis describes an experimental and analytical investigation of thermal hydraulic characteristics of low temperature helium in conventional and hybrid CICCS. Pressure drop measurements for both NET and CEA conductors have been conducted, using low temperature helium and liquid nitrogen to obtain a range of Reynolds numbers. The results are correlated with classical friction factor and Reynolds number analysis. The flow impedance reduction of the CEA conductor is described by measures of a developed flow model. Thermally induced flow in the CEA conductor has been studied with an inductive heating method. The induced velocity in the central channel is measured by a Pitot tube with steady state Reynolds number up to {approximately}7000. The transient pressure wave propagation has been recorded with pressure transducers placed equally along the conductor. The supercritical helium temperature in the central channel has been measured with the thermometer probe. However, the reduction of the central channel area significantly affects the overall thermal hydraulic characteristics of the conductor. The results suggest the importance of the central channel. A transient heat transfer experiment studied the.transverse heat transfer mechanism in the CEA conductor. The temperatures in the central channel and bundle region were measured with different sized heat pulses. The results are discussed in terms of a heat transfer model which is based upon the communication of the helium in the central channel and bundle.

  14. A new model for bubble growth, deformation and coalescence for conduit dynamics

    Science.gov (United States)

    Huber, C.; Nguyen, C.; Dufek, J.; Gonnermann, H. M.

    2011-12-01

    The buoyancy of bubbles and the conditions under which they grow (equilibrium vs disequilibrium) control the behavior of the magma during volcanic eruptions. The high vesicularity measured in pumices deposited during explosive eruptions indicates that fragmentation generally occurs at high bubble volume fractions (>0.6). It therefore suggests that dynamical processes associated with high bubble volume fraction, such as bubble-bubble hydrodynamic interactions (deformation), coalescence, and differential bubble growth, can exert an important control on the eruption. We propose a new bubble dynamics model that focuses on bubble growth, bubble-bubble interactions and coalescence at high vesicularity. This model is based on multiphase flow calculations using a free surface lattice Boltzmann model. At the present time, the model is 2D and allows us to track the evolution of a few hundred bubbles distributed heterogeneously in space and growing from a supersaturated melt (sudden or continuous decompression are possible). A key feature of the model is its ability to accurately solve bubble deformation and coalescence under decompression and/or shear flow conditions. Coalescence, in our model, is calibrated against new laboratory experiments of bubble ascent under a free surface (see Chinh et al. abstract, this AGU meeting). We present numerical results for the evolution of the bubble size distribution (and its different statistical moments) as a consequence of decompression, as well as shear deformation. We also compute the distribution of gas pressure in the heterogeneous bubble population. The model is used to construct a new parameterizations to account for (1) hydrodynamic forces resulting from bubble interactions applied on the silicate melt (drag), and, (2) the evolution of the heterogeneous distribution of bubble size and pressure. Lastly, we discuss how these parameterizations can be incorporated in conduit flow models to solve for the evolution of the multiphase magma mixture more accurately, as it approaches fragmentation conditions.

  15. Sequential internal mammary artery grafts. Expanded utilization of an ideal conduit

    International Nuclear Information System (INIS)

    The internal mammary artery, when used as a conduit for coronary artery bypass, offers a better long-term patency rate and survival rate than the saphenous vein; however, its utility has been limited. Among other factors, the availability of only two internal mammary arteries for anastomosis has been a major limitation. In an attempt to overcome this limitation, the authors constructed sequential internal mammary artery grafts in 87 patients. In 49 patients (Group I), only one internal mammary artery was used for sequential anastomosis. In another 31 patients (Group II), one internal mammary artery was used for sequential anastomosis and the other was used for single end-to-side anastomosis. Both internal mammary arteries were used in seven patients (Group III) for the construction of sequential anastomoses. Postoperatively, 64 patients were evaluated by exercise stress tests. None of these patients had a positive stress test although seven patients (11%) had electrocardiographic changes that were considered equivocal. Coronary angiography was performed in 35 of the 87 patients, with 92 vein grafts and 90 internal mammary artery anastomotic sites evaluated within 1 year of operation. A total of 83 vein grafts and 84 internal mammary artery anastomotic sites evaluated within 1 year of operation. A total of 83 vein grafts and 84 internal mammary artery anastomoses were found to be patent. Thus the patency rate for vein grafts was 90% and for internal mammary artery grafts, 93%. During the follow-up period (8 to 52 months), three patients died and one was lost to follow-up. Among the remaining patients, 79 had complete relief from symptoms, three had minimal symptoms, and one patient obtained no relief from symptoms

  16. Simulation of Epitaxial Silicon Chemical Vapor Deposition in Barrel Reactors

    OpenAIRE

    Masi, M; Fogliani, S.; Carrà, S.

    1995-01-01

    the epitaxial silicon chemical vapor deposition by SiCl4/H2 mixtures in a LPE 861 barrel reactor has been simulated by means of a detailed 2D model solved by the commercial finite element code FIDAP. Different reactor configurations (i.e., bel1 diameter, gas diffusors, susceptor tilting angle) and deposition conditions (i.e., flow rates and reactor pressure) have been examined. The simulation have been satisfactorily compared with experimental growth rate data measured along the reactor axial...

  17. Role of nearest-neighbor drops in the kinetics of homogeneous nucleation in a supersaturated vapor

    Science.gov (United States)

    Grinin, A. P.; Zhuvikina, I. A.; Kuni, F. M.; Reiss, H.

    2004-12-01

    A theory of simultaneous nucleation and drop growth in a supersaturated vapor is developed. The theory makes use of the concept of "nearest-neighbor" drops. The effect of vapor heterogeneity caused by vapor diffusion to a growing drop, formed previously, is accounted for by considering the nucleation of the nearest-neighbor drop. The diffusional boundary value problem is solved through the application of a recent theory that maintains material balance between the vapor and the drop, even though the drop boundary is a moving one. This is fundamental to the use of the proper time and space dependent vapor supersaturation in the application of nucleation theory. The conditions are formulated under which the mean distance to the nearest-neighbor drop and the mean time to its appearance can be determined reliably. Under these conditions, the mean time provides an estimate of the duration of the nucleation stage, while the mean distance provides an estimate of the number of drops formed per unit volume during the nucleation stage. It turns out, surprisingly, that these estimates agree fairly well with the predictions of the simpler and more standard approach based on the approximation that the density of the vapor phase remains uniform during the nucleation stage. Thus, as a practical matter, in many situations, the use of the simpler and less rigorous method is justified by the predictions of the more rigorous, but more complicated theory.

  18. Glacier surge mechanism based on linked cavity configuration of the basal water conduit system

    Science.gov (United States)

    Kamb, Barclay

    1987-08-01

    Based on observations of the 1982-1983 surge of Variegated Glacier, Alaska, a model of the surge mechanism is developed in terms of a transition from the normal tunnel configuration of the basal water conduit system to a linked cavity configuration that tends to restrict the flow of water, resulting in increased basal water pressures that cause rapid basal sliding. The linked cavity system consists of basal cavities formed by ice-bedrock separation (cavitation), ˜1 m high and ˜10 m in horizontal dimensions, widely scattered over the glacier bed, and hydraulically linked by narrow connections where separation is minimal (separation gap ? 0.1 m). The narrow connections, called orifices, control the water flow through the conduit system; by throttling the flow through the large cavities, the orifices keep the water flux transmitted by the basal water system at normal levels even though the total cavity cross-sectional area (˜200 m2) is much larger than that of a tunnel system (˜10 m2). A physical model of the linked cavity system is formulated in terms of the dimensions of the "typical" cavity and orifice and the numbers of these across the glacier width. The model concentrates on the detailed configuration of the typical orifice and its response to basal water pressure and basal sliding, which determines the water flux carried by the system under given conditions. Configurations are worked out for two idealized orifice types, step orifices that form in the lee of downglacier-facing bedrock steps, and wave orifices that form on the lee slopes of quasisinusoidal bedrock waves and are similar to transverse "N channels." The orifice configurations are obtained from the results of solutions of the basal-sliding-with-separation problem for an ice mass constituting of linear half-space of linear rheology, with nonlinearity introduced by making the viscosity stress-dependent on an intuitive basis. Modification of the orifice shapes by melting of the ice roof due to viscous heat dissipation in the flow of water through the orifices is treated in detail under the assumption of local heat transfer, which guarantees that the heating effects are not underestimated. This treatment brings to light a melting-stability parameter ? that provides a measure of the influence of viscous heating on orifice cavitation, similar but distinct for step and wave orifices. Orifice shapes and the amounts of roof meltback are determined by ?. When ? ? 1, so that the system is "viscous-heating-dominated," the orifices are unstable against rapid growth in response to a modest increase in water pressure or in orifice size over their steady state values. This growth instability is somewhat similar to the jökulhlaup-type instability of tunnels, which are likewise heating-dominated. When ? ? 1, the orifices are stable against perturbations of modest to even large size. Stabilization is promoted by high sliding velocity ?, expressed in terms of a ?-½ and ?-1 dependence of ? for step and wave cavities. The relationships between basal water pressure and water flux transmitted by linked cavity models of step and wave orifice type are calculated for an empirical relation between water pressure and sliding velocity and for a particular, reasonable choice of system parameters. In all cases the flux is an increasing function of the water pressure, in contrast to the inverse flux-versus-pressure relation for tunnels. In consequence, a linked cavity system can exist stably as a system of many interconnected conduits distributed across the glacier bed, in contrast to a tunnel system, which must condense to one or at most a few main tunnels. The linked cavity model gives basal water pressures much higher than the tunnel model at water fluxes ?1 m3/s if the bed roughness features that generate the orifices have step heights or wave amplitudes less than about 0.1 m. The calculated basal water pressure of the particular linked cavity models evaluated is about 2 to 5 bars below ice overburden pressure for water fluxes in the

  19. An integrated approach for catchment delineation and conduit-network modeling in karst aquifers: application to a site in the Swiss tabular Jura

    Science.gov (United States)

    Malard, Arnauld; Jeannin, Pierre-Yves; Vouillamoz, Jonathan; Weber, Eric

    2015-07-01

    An essential issue in karst hydrology is the characterization of the hydrogeological flow systems, i.e., the delineation of catchment areas and the organization of the main flow paths (conduit network) feeding one or several outlets. The proposed approach provides an explicit way to sketch catchment areas, and to generate karst conduits on the basis of a three-dimensional (3D) conceptual model of the aquifer (KARSYS approach). The approach follows three main principles: (1) conduits develop according to the hydraulic gradient, which depends on the aquifer zonation, (2) conduits are guided by preferential guidance features (or inception horizons) prevailing in the unsaturated and saturated zones of the aquifer, and (3) conduits initiate on a regular basis below the autogenic zone of the catchment area. This approach was applied to a site in the Swiss Jura as a base for the assessment of flood-hazard risks. The resulting model proposes a new delineation of the system catchment area and appears fairer regarding hydrological measurements than previous interpretations, which under-estimated the catchment area by about 20 %. Furthermore, the proposed conduit network for the whole aquifer is also consistent with local cave surveys and dye-tracing observations. These interesting results demonstrate that the combination of this approach with the KARSYS 3D model provides an integrated and effective way for the characterization of karst-flow systems.

  20. An integrated approach for catchment delineation and conduit-network modeling in karst aquifers: application to a site in the Swiss tabular Jura

    Science.gov (United States)

    Malard, Arnauld; Jeannin, Pierre-Yves; Vouillamoz, Jonathan; Weber, Eric

    2015-11-01

    An essential issue in karst hydrology is the characterization of the hydrogeological flow systems, i.e., the delineation of catchment areas and the organization of the main flow paths (conduit network) feeding one or several outlets. The proposed approach provides an explicit way to sketch catchment areas, and to generate karst conduits on the basis of a three-dimensional (3D) conceptual model of the aquifer (KARSYS approach). The approach follows three main principles: (1) conduits develop according to the hydraulic gradient, which depends on the aquifer zonation, (2) conduits are guided by preferential guidance features (or inception horizons) prevailing in the unsaturated and saturated zones of the aquifer, and (3) conduits initiate on a regular basis below the autogenic zone of the catchment area. This approach was applied to a site in the Swiss Jura as a base for the assessment of flood-hazard risks. The resulting model proposes a new delineation of the system catchment area and appears fairer regarding hydrological measurements than previous interpretations, which under-estimated the catchment area by about 20 %. Furthermore, the proposed conduit network for the whole aquifer is also consistent with local cave surveys and dye-tracing observations. These interesting results demonstrate that the combination of this approach with the KARSYS 3D model provides an integrated and effective way for the characterization of karst-flow systems.

  1. Volcanic risk metrics at Mt Ruapehu, New Zealand: some background to a probabilistic eruption forecasting scheme and a cost/benefit analysis at an open conduit volcano

    Science.gov (United States)

    Jolly, Gill; Sandri, Laura; Lindsay, Jan; Scott, Brad; Sherburn, Steve; Jolly, Art; Fournier, Nico; Keys, Harry; Marzocchi, Warner

    2010-05-01

    The Bayesian Event Tree for Eruption Forecasting software (BET_EF) is a probabilistic model based on an event tree scheme that was created specifically to compute long- and short-term probabilities of different outcomes (volcanic unrest, magmatic unrest, eruption, vent location and eruption size) at long-time dormant and routinely monitored volcanoes. It is based on the assumption that upward movements of magma in a closed conduit volcano will produce detectable changes in the monitored parameters at the surface. In this perspective, the goal of BET_EF is to compute probabilities by merging information from geology, models, past data and present monitoring measurements, through a Bayesian inferential method. In the present study, we attempt to apply BET_EF to Mt Ruapehu, a very active and well-monitored volcano exhibiting the typical features of open conduit volcanoes. In such conditions, current monitoring at the surface is not necessarily able to detect short term changes at depth that may occur only seconds to minutes before an eruption. This results in so-called "blue sky eruptions" of Mt Ruapehu (for example in September 2007), that are volcanic eruptions apparently not preceded by any presently detectable signal in the current monitoring. A further complication at Mt Ruapehu arises from the well-developed hydrothermal system and the permanent crater lake sitting on top of the magmatic conduit. Both the hydrothermal system and crater lake may act to mask or change monitoring signals (if present) that magma produces deeper in the edifice. Notwithstanding these potential drawbacks, we think that an attempt to apply BET_EF at Ruapehu is worthwhile, for several reasons. First, with the exception of a few "blue sky" events, monitoring data at Mt Ruapehu can be helpful in forecasting major events, especially if a large amount of magma is intruded into the edifice and becomes available for phreatomagmatic or magmatic eruptions, as for example in 1995-96. Secondly, in setting up BET_EF for Mt Ruapehu we are forced to define quantitatively what the background activity is. This will result in a quantitative evaluation of what changes in long time monitored parameters may influence the probability of future eruptions. The slopes of Mt Ruapehu host the largest ski area in North Island, New Zealand. Lahars have been generated as a result of several eruptions in the last 50 years, and some of these have reached the ski runs in a very short time frame (around 90 seconds from the beginning of the eruption). In the light of these potentially hazardous lahars, we use the output probabilities provided by BET_EF in a practical and rational decision scheme recently proposed by Marzocchi and Woo (2009) based on a cost/benefit analysis (CBA). In such scheme, a C/L ratio is computed, based on the costs (C) of practical mitigation actions to reduce risk (e.g., a public warning scheme and other means of raising awareness, and a call for a temporary and/or partial closure of the ski area) and on the potential loss (L) if no mitigation action is taken and an eruption occurs causing lahars down the ski fields. By comparing the probability of eruption-driven lahars and the C/L ratio, it is possible to define the most rational mitigation actions that can be taken to reduce the risk to skiers, snowboarders and staff on skifield. As BET_EF probability of eruption changes dynamically as updated monitoring data are received, the authorities can decide, at any specific point in time, what is the best action according to the current monitoring of the volcano. In this respect, CBA represents a bridge linking scientific output (probabilities) and Decision Makers (practical mitigation actions).

  2. On mechanism of formation of polymer coatings in radiation vapor-phase capsulation of large-dispersed solids

    International Nuclear Information System (INIS)

    The adsorptional vapor-phase mechanism of formation of polymer coatings on large-dispersed solids under ?-irradiation in medium of monomers vapors (in particular methylmethacrylate) is proposed. The basis of the coating are the polymer globules of the microne size being formed in the vapor phase and trapped by the surface of capsulated particles. The subsequent growth of these globules on the surface by means of graft polymerization of adsorbed monomer results in formation of compact coating having low diffusional permeability. The main features of the method of radiation-induced vapor-phase capsulation of large-dispersed solids are formulated

  3. Controlled VLS Growth of Indium, Gallium and Tin Oxide Nanowiresvia Chemical Vapor Transport

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, M.C.; Aloni, S.; McCready, D.E.; Bourret-Courchesne, E.D.

    2006-03-13

    We utilized a vapor-liquid-solid growth technique to synthesize indium oxide, gallium oxide, and tin oxide nanowires using chemical vapor transport with gold nanoparticles as the catalyst. Using identical growth parameters we were able to synthesize single crystal nanowires typically 40-100 nm diameter and more than 10-100 microns long. The products were characterized by means of XRD, SEM and HRTEM. All the wires were grown under the same growth conditions with growth rates inversely proportional to the source metal vapor pressure. Initial experiments show that different transparent oxide nanowires can be grown simultaneously on a single substrate with potential application for multi-component gas sensors.

  4. Instability arisen on condensing vapor bubble

    Science.gov (United States)

    Ueno, Ichiro; Hosoya, Ryota; Hong, Chungpyo

    2012-11-01

    In the present study a special attention is paid to the growing and collapsing processes of vapor bubble injected into a subcooled pool; the authors try to extract the vapor-liquid interaction by employing a vapor generator that supplies vapor at designated flow rate to the subcooled pool instead of using a immersed heated surface to realize a vapor bubble by boiling phenomenon. This system enables ones to detect a spatio-temporal behavior of a single bubble of superheated vapor exposed to a subcooled liquid. The authors indicate the condensation rates as functions of the injection velocity of the vapor and the degree of subcooling of the pool. The authors indicate that an abrupt condensation of the injected vapor results in a fine disturbance over the vapor bubble surface before the collapse stage of the bubble. The wave number is sharply dependent on the degree of subcooling of the pool. The threshold of such a fine disturbance formation over the bubble corresponds with that the occurring condition of the maximum volume reduction rate of the vapor bubble. This work is supported by Grant-in-Aid for Scientific Research (B) (project #: 24360085) from Japan Society for the Promotion of Science (JSPS).

  5. Liquid-vapor phase transition in nuclei or compound nucleus decay?

    OpenAIRE

    Moretto, L. G.; Elliott, J. B.; Phair, L.; Wozniak, G. J.

    2002-01-01

    Recent analyses of multifragmentation in terms of Fisher's model and the related construction of a phase diagram brings forth the problem of the true existence of the vapor phase and the meaning of its associated pressure. Our analysis shows that a thermal emission picture is equivalent to a Fisher-like equilibrium description which avoids the problem of the vapor and explains the recently observed Boltzmann-like distribution of the emission times. In this picture a simple F...

  6. The oscillation of vapor bubbles

    Science.gov (United States)

    Prosperetti, Andrea; Yin, Zhizhong

    2001-05-01

    Bob Apfel had so many interests that it is impossible-however fitting and desirable-to pay homage to his work as a whole. Some of his early studies were devoted to bubble nucleation at high superheats. In the first part of this paper a recent application of this phenomenon is described. Once a vapor bubble is generated, its subsequent oscillations (free and forced) present analogies and differences with those of a gas bubble: the second part of the paper focuses on this topic. [Work supported by NSF and NASA.

  7. The oscillations of vapor bubbles

    Science.gov (United States)

    Prosperetti, Andrea; Yin, Z.; Yang, B.

    2003-04-01

    Bob Apfel had so many interests that it is impossible-however fitting and desirable-to pay homage to his work as a whole. Some of his early studies were devoted to bubble nucleation at high superheats. In the first part of this paper a recent application of this phenomenon is described. Once a vapor bubble is generated, its subsequent oscillations (free and forced) present analogies and differences with those of a gas bubble: the second part of the paper focuses on this topic. [Work supported by NSF and NASA.

  8. Microwave assisted chemical vapor infiltration

    International Nuclear Information System (INIS)

    A microwave assisted process for production of continuous fiber reinforced ceramic matrix composites is described. A simple apparatus combining a chemical vapor infiltration reactor with a conventional 700 W multimode oven is described. Microwave induced inverted thermal gradients are exploited with the ultimate goal of reducing processing times on complex shapes. Thermal gradients in stacks of SiC (Nicalon) cloths have been measured using optical thermometry. Initial results on the ''inside out'' deposition of SiC via decomposition of methyltrichlorosilane in hydrogen are presented. Several key processing issues are identified and discussed. 5 refs

  9. Wick for metal vapor laser

    Science.gov (United States)

    Duncan, David B. (Livermore, CA)

    1992-01-01

    An improved wick for a metal vapor laser is made of a refractory metal cylinder, preferably molybdenum or tungsten for a copper laser, which provides the wicking surface. Alternately, the inside surface of the ceramic laser tube can be metalized to form the wicking surface. Capillary action is enhanced by using wire screen, porous foam metal, or grooved surfaces. Graphite or carbon, in the form of chunks, strips, fibers or particles, is placed on the inside surface of the wick to reduce water, reduce metal oxides and form metal carbides.

  10. Water vapor diffusion membrane development

    Science.gov (United States)

    Tan, M. K.

    1976-01-01

    A total of 18 different membranes were procured, characterized, and tested in a modified bench-scale vapor diffusion water reclamation unit. Four membranes were selected for further studies involving membrane fouling. Emphasis was placed on the problem of flux decline due to membrane fouling. This is discussed in greater details under "Summary and Discussion on Membrane Fouling Studies" presented in pages 47-51. The system was also investigated for low temperature application on wash-water where the permeated water is not recovered but vented into space vacuum.

  11. Chemical vapor deposition of sialon

    Science.gov (United States)

    Landingham, Richard L. (Livermore, CA); Casey, Alton W. (Livermore, CA)

    1982-01-01

    A laminated composite and a method for forming the composite by chemical vapor deposition. The composite includes a layer of sialon and a material to which the layer is bonded. The method includes the steps of exposing a surface of the material to an ammonia containing atmosphere; heating the surface to at least about 1200.degree. C.; and impinging a gas containing in a flowing atmosphere of air N.sub.2, SiCl.sub.4, and AlCl.sub.3 on the surface.

  12. Advanced Raman water vapor lidar

    Science.gov (United States)

    Whiteman, David N.; Melfi, S. Harvey; Ferrare, Richard A.; Evans, Keith A.; Ramos-Izquierdo, Luis; Staley, O. Glenn; Disilvestre, Raymond W.; Gorin, Inna; Kirks, Kenneth R.; Mamakos, William A.

    1992-01-01

    Water vapor and aerosols are important atmospheric constituents. Knowledge of the structure of water vapor is important in understanding convective development, atmospheric stability, the interaction of the atmosphere with the surface, and energy feedback mechanisms and how they relate to global warming calculations. The Raman Lidar group at the NASA Goddard Space Flight Center (GSFC) developed an advanced Raman Lidar for use in measuring water vapor and aerosols in the earth's atmosphere. Drawing on the experience gained through the development and use of our previous Nd:YAG based system, we have developed a completely new lidar system which uses a XeF excimer laser and a large scanning mirror. The additional power of the excimer and the considerably improved optical throughput of the system have resulted in approximately a factor of 25 improvement in system performance for nighttime measurements. Every component of the current system has new design concepts incorporated. The lidar system consists of two mobile trailers; the first (13m x 2.4m) houses the lidar instrument, the other (9.75m x 2.4m) is for system control, realtime data display, and analysis. The laser transmitter is a Lambda Physik LPX 240 iCC operating at 400 Hz with a XeF gas mixture (351 nm). The telescope is a .75m horizontally mounted Dall-Kirkham system which is bore sited with a .8m x 1.1m elliptical flat which has a full 180 degree scan capability - horizon to horizon within a plane perpendicular to the long axis of the trailer. The telescope and scan mirror assembly are mounted on a 3.65m x .9m optical table which deploys out the rear of the trailer through the use of a motor driven slide rail system. The Raman returns from water vapor (403 nm), nitrogen (383 nm) and oxygen (372 nm) are measured in addition to the direct Rayleigh/Mie backscatter (351). The signal from each of these is split at about a 5/95 ratio between two photomultiplier detectors. The 5 percent detector is used for measurements below about 4.0 km, while the 95 percent detector provides the information above this level.

  13. Chemical vapor deposited zinc sulfide

    CERN Document Server

    McCloy, John S

    2013-01-01

    Zinc sulfide has shown unequaled utility for infrared windows that require a combination of long-wavelength infrared transparency, mechanical durability, and elevated-temperature performance. This book reviews the physical properties of chemical vapor deposited ZnS and their relationship to the CVD process that produced them. An in-depth look at the material microstructure is included, along with a discussion of the material's optical properties. Finally, because the CVD process itself is central to the development of this material, a brief history is presented.

  14. Rheology contrast in the shallow conduit and eruption dynamics at Stromboli: insights from analogue experiments

    Science.gov (United States)

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

    2014-05-01

    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 control 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 conduit (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 (? = 0.1 Pa*s) capped with castor oil (? = 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 control 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 controls slug expansion and systematically changes the magnitude of the associated pressure transients, favouring a more impulsive and energetic pressure release compared with the control experiments. The intrusion of slugs in the viscous plug leads to complex flow configurations: small slugs can enter the viscous plug either partly or wholly before bursting. Large slugs lead to complex interaction between the two liquids: the intrusion of the low-viscosity liquid into the high-viscosity one provides a preferential pathway for the slugs. The viscous plug generates an annulus of variable thickness acting as a narrowing of the tube. Furthermore, higher gas volumes can induce both instabilities in the falling film and the disruption of the viscous annulus, clots of which are brought to the top by the slug.

  15. Microxenoliths from the Slave craton: Archives of diamond formation along fluid conduits

    Science.gov (United States)

    Aulbach, Sonja; Stachel, Thomas; Heaman, Larry M.; Carlson, Jon A.

    2011-10-01

    A suite of 23 diamondiferous microxenoliths from the Ekati kimberlites in the central Slave craton was studied to elucidate the tectonothermal evolution of the lithosphere during craton formation and modification along craton margins, and associated diamond formation. Major- and trace-element abundances of eclogites (n = 16) reveal the presence of two compositionally distinct suites: a group of three eclogites with typical gabbroic trace-element patterns (flat REE N and low ΣREE, positive Sr N and Pb N, negative Zr N anomalies) and a group of 13 eclogites that are characterised by lower Mg#, Cr, Sc and Sr combined with higher Al 2O 3, TiO 2 and Na 2O, and a conspicuously stepped REE pattern with lower LREE/HREE. Inclusions in diamonds from the central Slave craton consistently plot with the latter group. The unusual trace-element characteristics of the second group are strikingly similar to those produced along fluid conduits in younger subduction zones, where infiltration of a metasomatic fluid induced eclogitisation. Eclogitic diamonds contain an average of 540 at.ppm nitrogen that is poorly aggregated (12% in the B centre), similar to eclogitic diamonds recovered from the A154 kimberlite (Diavik Mine, ~ 30 km southeast) that were dated to 1.85 Ga and linked to subduction at the western craton margin. This suggests that (1) by 1.85 Ga subduction-related reactive fluid transport and element mobilisation similar to younger examples were established, and (2) this fluid flow not only catalysed eclogitisation of subducting oceanic crust, but also was a prerequisite for the majority of eclogitic diamond formation beneath the central Slave craton. Harzburgitic and lherzolitic diamondiferous microxenoliths (n = 4) may document diamond formation in the Slave craton prior to emplacement of eclogites. Peridotitic garnets have sinusoidal REE-patterns with strong depletions in Ti, consistent with carbonate-melt or fluid metasomatism that may have also prompted diamond growth. Their temperatures of last equilibration (~ 1020 to 1300 °C), combined with diamond N characteristics are consistent with precipitation precontemporaneously to ~ 3.3 Ga formation of the deep Slave lithosphere from carbonatitic melts or fluids derived from below the lithosphere-asthenosphere boundary.

  16. Thermogravimetric measurements of liquid vapor pressure

    International Nuclear Information System (INIS)

    Highlights: ? Rapid determination of vapor pressure by TGA. ? Demonstration of limitations of currently available approaches in literature. ? New model for vapor pressure assessment of small size samples in TGA. ? New model accounts for vapor diffusion and sample geometry and measures vapor pressure normally within 10%. - Abstract: A method was developed using thermo-gravimetric analysis (TGA) to determine the vapor pressure of volatile liquids. This is achieved by measuring the rate of evaporation (mass loss) of a pure liquid contained within a cylindrical pan. The influence of factors like sample geometry and vapor diffusion on evaporation rate are discussed. The measurement can be performed across a wide range of temperature yielding reasonable results up to 10 kPa. This approach may be useful as a rapid and automatable method for measuring the volatility of flavor and fragrance raw materials.

  17. Cirurgia coronária com condutos arteriais múltiplos sem circulação extracorpórea Off-pump coronary artery bypass with multiple arterial conduits

    Directory of Open Access Journals (Sweden)

    Daniel Navia

    2005-03-01

    Full Text Available OBJETIVO: Analisar os resultados, em 30 dias, em pacientes submetidos de forma eletiva à revascularização arterial total do miocárdio sem circulação extracorpórea (CEC, e identificar preditores de morbimortalidade com esta estratégia cirúrgica. MÉTODO: Entre maio de 1999 e fevereiro de 2004, efetuaram-se 203 cirurgias de revascularização miocárdica (CRM com revascularização arterial total sem CEC, em pacientes com doença de múltiplos vasos (três vasos 81,7%, doença de um vaso excluída. Reportaram-se variáveis pré-operatórias e comorbidade: média de idade 63,9 ± 9,13 anos, homens 182 (89,5%, hipertensão 132 (65%, tabagismo 125 (61%, hipercolesterolemia 152 (74,8%, infarto agudo do miocárdio prévio (mais de 30 dias 73 (35%, disfunção ventricular moderada a grave 31 (15%, reoperação cinco (2,5%. A revascularização arterial total incluiu anastomoses em T e seqüenciais com artéria torácica interna esquerda (100%, torácica interna direita (56,6% e artéria radial (63%. O número total de anastomoses foi 576 (média de três pontes/paciente, todas efetuadas com estabilizadores mecânicos externos. Não form realizadas anastomoses proximais na aorta. Cirurgia com CEC foi realizada em três (1,5% pacientes. Noventa por cento dos pacientes foram extubados na sala de operações. Para a análise estatística, utilizou-se teste de regressão logística múltipla. RESULTADOS: A incidência de fibrilação atrial pós-operatória foi de 12,8% (26, insuficiência renal oligoanúrica 3% (seis, diálise 0,49% (um, infarto de miocárdio pós-operatório 1,47% (três, baixo débito cardíaco 4% (oito, reoperação por sangramento 1,47% (três, mediastinite 1,47% (três, acidente vascular cerebral 1,47% (três. A mortalidade intra-hospitalar foi de 2,45% (cinco. O único preditor independente de morbidade em 30 dias foi a idade (p=0,033; OR 1,04; IC 95%: 1-1,08. CONCLUSÃO: A cirurgia de revascularização miocárdica sem circulação extracorpórea utilizando condutos arteriais para a doença de múltiplos vasos é factível com baixa morbimortalidade em 30 dias.OBJECTIVE: To analyze intra-hospital results in patients undergoing elective off-pump total arterial revascularization and identify morbidity and mortality predictors using this surgical strategy. METHOD: From May 1999 to February 2004, 203 myocardial revascularization procedures with total arterial revascularization without cardiopulmonary bypass (off-pump were carried out in patients with multivessel disease (three vessels 81.7 %, one vessel disease was excluded. We report pre-surgical variables and co-morbidities: average age 63.9 ± 9.13 years, men 182 (89.5%, hypertension 132 (65%, smokers 125 (61%, hypercholesterolemia 152 (74.8%, previous myocardial infarction (> 30 days 73 (35%, moderate to severe ventricular dysfunction 31 (15%, redo five (2.5%. Total arterial revascularization included T-grafts and sequential grafts with left internal mammary (100%, right internal mammary (56.6% and radial (63% arteries. The total number of distal anastomosis was 576 (mean of three grafts/patient, all carried out with external mechanical stabilizers. There were no proximal aortic anastomoses. Conversion to on-pump surgery occurred in three (1.5% patients; 90% of the patients was extubated in the operating room. The multiple logistic regression test was used for statistical analysis. RESULTS: The postoperative incidence of atrial fibrillation was 12.8% (26, oligoanuric renal failure 3% (six, dialysis 0.49% (one, postoperative myocardial infarction 1.47% (three, low cardiac output 4% (eight, Redo for bleeding 1.47% (three, mediastinitis 1.47% (three, stroke 1.47% (three. Intra-hospital mortality was 2.45% (five. The only independent 30 day morbidity predictor was age (p=0.033; OR 1.04; IC 95%: 1-1.08. CONCLUSION: Off-pump myocardial revascularization with arterial conduits for multiple vessel disease is feasible with a low 30-day morbidity and mortality.

  18. Satellite radar data reveal short-term pre-explosive displacements and a complex conduit system at Volcán de Colima, Mexico

    Science.gov (United States)

    Salzer, Jacqueline; Nikkhoo, Mehdi; Walter, Thomas; Sudhaus, Henriette; Reyes-Dávila, Gabriel; Bretón, Mauricio; Arambula, Raúl

    2014-06-01

    The geometry of the volcanic conduit is a main parameter controlling the dynamics and the style of volcanic eruptions and their precursors, but also one of the main unknowns. Pre-eruptive signals that originate in the upper conduit region include seismicity and deformation of different types and scales. However, the locality of the source of these signals and thus the conduit geometry often remain unconstrained at steep sloped and explosive volcanoes due to the sparse instrumental coverage in the summit region and difficult access. Here we infer the shallow conduit system geometry of Volcán de Colima, Mexico, based on ground displacements detected in high resolution satellite radar data up to seven hours prior to an explosion in January 2013. We use Boundary Element Method modeling to reproduce the data synthetically and constrain the parameters of the deformation source, in combination with an analysis of photographs of the summit. We favour a two-source model, indicative of distinct regions of pressurization at very shallow levels. The location of the upper pressurization source coincides with that of post-explosive extrusion; we therefore attribute the displacements to transient (elastic) pre-explosive pressurization of the conduit system. Our results highlight the geometrical complexity of shallow conduit systems at explosive volcanoes and its effect on the distribution of pre-eruptive deformation signals. An apparent absence of such signals at many explosive volcanoes may relate to its small temporal and spatial extent, partly controlled by upper conduit structures. Modern satellite radar instruments allow observations at high spatial and temporal resolution that may be the key for detecting and improving our understanding of the generation of precursors at explosive volcanoes.

  19. Well hydrograph analysis for the characterisation of flow dynamics and conduit network geometry in a karst aquifer, Bükk Mountains, Hungary

    Science.gov (United States)

    Kovács, Attila; Perrochet, Pierre; Darabos, Enik?; Lénárt, László; Sz?cs, Péter

    2015-11-01

    The present paper introduces new well hydrograph analytical tools for parameter estimation in karst aquifers. The analytical formulae provided in this study link aquifer properties with hydrograph recession coefficients, and provide quantitative characterisation of the spatial and temporal variations of the water table. Generally, spring hydrograph analytical techniques provide information on the characteristic hydraulic parameters and conduit spacing in a karstic catchment, while well hydrograph analysis provides information on local hydraulic and geometric properties of individual matrix blocks and in certain cases on the deep unkarstified aquifer zone. The combination of the spring and well hydrograph analytical methods represents a useful tool for understanding the structure and hydraulic behaviour of karst systems. A new well hydrograph analytical approach is presented, which makes the estimation of conduit spacing and catchment geometries possible. In most cases well hydrograph peaks can be decomposed into three exponential segments. Exponential segments in shallow systems do not correspond to different types of storage, but in most cases originate from the emptying of fissured matrix blocks. The proposed parameter estimation method is demonstrated through the application of field data. The test site is located in the Bükk Mountains, Hungary. Analytical methods were applied on two adjacent karstic catchments feeding the Szinva and Garadna springs. Hydrograph analysis of both springs and three well hydrographs were performed to investigate the hydraulic behaviour of the karst system and to estimate the spatial geometry of karst conduits. According to hydrograph analytical results, both spring and well hydrographs indicated similar matrix block geometries. Hydrograph analysis revealed the change of flow scale indicated by a significant drop of the value of recession coefficient. The investigation method introduced in this study provides important information for water resource assessment, contamination risk assessment, vulnerability assessment, flood prediction, geotechnical and speleological studies.

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

    Science.gov (United States)

    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.

  1. Algorithmes de vision pour la pluie et les feux tricolores pour les systèmes d'aide à la conduite

    OpenAIRE

    De Charette, Raoul

    2012-01-01

    L'utilisation d'algorithmes de vision permettrait d'élargir le domaine d'application des systèmes d'aide à la conduite à d'autres situations telles que : les scènes urbaines ou les conditions météorologiques dégradées. À cette fin, trois nouvelles applications sont étudiées dans cette thèse pour la pluie et les feux tricolores. La pluie est la condition météorologique dégradée la plus fréquente. Nous comparons les modèles physiques et photométriques existants pour la pluie et les gouttes de p...

  2. Dummy coil development for the cable-in-conduit Nb3Sn ''outsert'' coils of the 45T hybrid magnet

    International Nuclear Information System (INIS)

    Intermagnetics General Corporation, under a Phase 1 contract with the National High Magnetic Field Laboratory at Florida State University, is developing and demonstrating the manufacturing technology for the cable-in-conduit conductor (CICC) for the Nb3Sn ''outsert'' coils of the 45T hybrid magnet. This paper presents the technical development of cabling and sheathing of long length dummy CICC and the progress of manufacturing development for the full-diameter coil ''A'' using the dummy CICC. This will include coil stress analyses, winding technique, Helium penetration ports, terminations, CIC conductor insulation, heat treatment and epoxy impregnation

  3. A vapor generator for transonic flow visualization

    Science.gov (United States)

    Bruce, Robert A.; Hess, Robert W.; Rivera, Jose A., Jr.

    1989-01-01

    A vapor generator was developed for use in the NASA Langley Transonic Dynamics Tunnel (TDT). Propylene glycol was used as the vapor material. The vapor generator system was evaluated in a laboratory setting and then used in the TDT as part of a laser light sheet flow visualization system. The vapor generator provided satisfactory seeding of the air flow with visible condensate particles, smoke, for tests ranging from low subsonic through transonic speeds for tunnel total pressures from atmospheric pressure down to less than 0.1 atmospheric pressure.

  4. Análise do tratamento cirúrgico da raiz da aorta com o tubo valvulado e com a preservação da valva aórtica Analysis of aortic root surgery with composite mechanical aortic valve conduit and valve-sparing reconstruction

    Directory of Open Access Journals (Sweden)

    Ricardo Ribeiro Dias

    2010-12-01

    Full Text Available OBJETIVO: Análise comparativa dos resultados imediatos e tardios da reconstrução da raiz da aorta com o tubo valvulado e com a preservação da valva aórtica. MÉTODOS: No período de novembro de 2002 a setembro de 2009, 164 pacientes com idade média de 54 ± 15 anos, sendo 115 do sexo masculino, foram submetidos ao tratamento cirúrgico da raiz da aorta. Foram 125 tubos valvulados e 39 reconstruções da raiz da aorta com preservação da valva aórtica. Dezesseis por cento dos pacientes eram portadores de síndrome de Marfan e 4,3% apresentavam valva aórtica bivalvulada. Cento e quarenta e quatro (88% pacientes foram acompanhados durante tempo médio de seguimento de 41,1 ± 20,8 meses. RESULTADOS: A mortalidade hospitalar total foi de 4,9%; sendo 5,6% nas operações com tubo valvulado e 2,6% nas preservações da valva aórtica (POBJECTIVE: Comparative analysis of early and late results of aortic root reconstruction with aortic valve sparing operations and the composite mechanical valve conduit replacement. METHODS: From November 2002 to September 2009, 164 consecutive patients with mean age 54 ± 15 years, 115 male, underwent the aortic root reconstruction (125 mechanical valve conduit replacements and 39 valve sparing operations. Sixteen percent of patients had Marfan syndrome and 4.3% had bicuspid aortic valve. One hundred and forty-four patients (88% were followed for a mean period of 41.1 ± 20.8 months. RESULTS: The hospital mortality was 4.9%, 5.6% in operations with valved conduits and 2.6% in the valve sparing procedures (P <0.05. There was no difference neither in survival (95% CI = 86% - 96%, P= 0.1 nor in reoperation-free survival (95% CI = 85% - 90%, P = 0.29. The survival free of complications such as bleeding, thromboembolism and endocarditis were favorable to the valve sparing operations, respectively (95% CI = 70% - 95%, P = 0.001, (95% CI = 82% - 95% P = 0.03 and (95% CI = 81% - 95%, P = 0.03. Multivariate analysis showed that creatinine greater than 1.4 mg/dl, Cabrol operation and renal dialysis were predictors of mortality, respectively, with occurrence chance of 6 (95% CI = 1.8 - 19.5, P = 0.003, 12 (95% CI = 3 - 49.7, P = 0.0004 and 16 (95% CI = 3.6 - 71.3, P = 0.0002. CONCLUSIONS: The aortic root reconstruction has a low early and late mortality, high survival free of complications and low need for reoperation. During the late follow-up, valve sparing aortic root reconstructions presented fewer incidences of bleeding, thromboembolic events and endocarditis.

  5. Making meaning(s with cover designs

    Directory of Open Access Journals (Sweden)

    Yvonne Reed

    2011-08-01

    Full Text Available In this article Halliday’s systemic functional grammar, Kress and Van Leeuwen’s grammar of visual design and Bernstein’s work on pedagogic discourse are drawn on in order to analyze some of the ways in which meanings are made and some meanings privileged over others in the designing, both visual and discursive, of the covers of three course books prepared for teacher education programmes in South Africa. The primary aim of this analysis is to understand what meanings are offered to readers as entrants into or as established members of communities of practice in the teaching profession and the academy.

  6. Water vapor and the dynamics of climate changes

    CERN Document Server

    Schneider, Tapio; Levine, Xavier

    2009-01-01

    Water vapor is not only Earth's dominant greenhouse gas. Through the release of latent heat when it condenses, it also plays an active role in dynamic processes that shape the global circulation of the atmosphere and thus climate. Here we present an overview of how latent heat release affects atmosphere dynamics in a broad range of climates, ranging from extremely cold to extremely warm. Contrary to widely held beliefs, atmospheric circulation statistics can change non-monotonically with global-mean surface temperature, in part because of dynamic effects of water vapor. For example, the strengths of the tropical Hadley circulation and of zonally asymmetric tropical circulations, as well as the kinetic energy of extratropical baroclinic eddies, can be lower than they presently are both in much warmer climates and in much colder climates. We discuss how latent heat release is implicated in such circulation changes, particularly through its effect on the atmospheric static stability, and we illustrate the circul...

  7. Three-layer microfibrous peripheral nerve guide conduit composed of elastin-laminin mimetic artificial protein and poly(L-lactic acid

    Directory of Open Access Journals (Sweden)

    TetsujiYamaoka

    2014-07-01

    Full Text Available We developed a microfibrous poly(L-lactic acid (PLLA nerve conduit with a three-layered structure to simultaneously enhance nerve regeneration and prevent adhesion of surrounding tissue. The inner layer was composed of PLLA microfiber containing 25% elastin-laminin mimetic protein (AG73-(VPGIG30 that promotes neurite outgrowth. The thickest middle layer was constructed of pure PLLA microfibers that impart the large mechanical stremgth to the conduit. A 10% poly(ethylene glycol was added to the outer layer to prevent the adhesion with the surrounding tissue. The AG73-(VPGIG30 composisting of an elastin-like repetitive sequence (VPGIG30 and a laminin-derived sequence (RKRLQVQLSIRT: AG73 was biosynthesized using Escherichia coli. The PLLA microfibrous conduits were fabricated using an electrospinning procedure. AG73-(VPGIG30 was successfully mixed in the PLLA microfibers, and the PLLA/AG73-(VPGIG30 microfibers were stable under physiological conditions. The PLLA/AG73-(VPGIG30 microfibers enhanced adhesion and neurite outgrowth of PC12 cells. The electrospun microfibrous conduit with a three-layered structure was implanted for bridging a 2.0-cm gap in the tibial nerve of a rabbit. Two months after implantation, no adhesion of surrounding tissue was observed, and the action potential was slightly improved in the nerve conduit with the PLLA/AG73-(VPGIG30 inner layer.

  8. Identifying and characterizing solution conduits in karst aquifers through geospatial (GIS) analysis of porosity from borehole imagery: An example from the Biscayne aquifer, South Florida (USA)

    Science.gov (United States)

    Manda, Alex K.; Gross, Michael R.

    2006-03-01

    We apply geospatial analysis to borehole imagery in an effort to develop new techniques to evaluate the spatial distribution and internal structure of karst conduits. Remote sensing software is used to classify a high resolution, digital borehole image of limestone bedrock from the Biscayne aquifer (South Florida, USA) into a binary image divided into cells of rock matrix and pores. Within a GIS, 2D porosity is calculated for a series of rectangular sampling windows placed over the binary image and then plotted as a function of depth. Potential conduits that intersect the borehole are identified as peaks of high porosity. A second GIS technique identifies a conduit as a continuous object that spans the entire borehole width. According to these criteria, geospatial analysis reveals ˜10 discrete conduits along the ˜15 m borehole image. Continuous sampling of the geologic medium intersected by the borehole provides insight into the internal structure of karst aquifers and the evolution of karst features. Most importantly, this pilot study demonstrates that GIS-based techniques are capable of quantifying the depths, dimensions, shapes, apertures and connectivity of potential conduits, physical attributes that impact flow in karst aquifers.

  9. The control of press cleaning solvent vapors in a small lithographic printing establishment.

    Science.gov (United States)

    Crouch, K G; Gressel, M G

    1999-05-01

    Small businesses frequently have inadequate in-house expertise to solve a variety of safety and health problems. The National Institute for Occupational Safety and Health (NIOSH) has therefore conducted a demonstration project in the commercial lithographic printing industry, which consists largely of small companies, in an effort to establish suitable control technology for airborne solvent vapors released primarily during press cleaning operations. These solvent vapors have a number of potential adverse health effects, including narcosis, kidney and liver damage, and cancer. Also, airborne anti-offset powder is a potential allergic sensitizer and cause of occupational asthma. As a means of controlling worker exposures to the vapors and dust, a local exhaust inlet was attached to the side of the press adjacent to the paper delivery point. Tempered outside air was introduced through ceiling outlets installed to make up for the exhausted air. Measurements of press operator exposure and area concentrations of solvent vapors and area concentration of anti-offset powder were made before and after installation of the new ventilation controls. Vapor concentrations were reduced by 73 percent for the press operators. Area concentrations of the vapors were reduced by 86 percent and dust concentration by 67 percent. The ventilation system was found to be suitable for vapor and dust control, although substitution of a cleaning solution containing non-carcinogenic solvents for solutions containing carcinogens was recommended. PMID:10446485

  10. Space-Time Variations in Water Vapor as Observed by the UARS Microwave Limb Sounder

    Science.gov (United States)

    Elson, Lee S.; Read, William G.; Waters, Joe W.; Mote, Philip W.; Kinnersley, Jonathan S.; Harwood, Robert S.

    1996-01-01

    Water vapor in the upper troposphere has a significant impact on the climate system. Difficulties in making accurate global measurements have led to uncertainty in understanding water vapor's coupling to the hydrologic cycle in the lower troposphere and its role in radiative energy balance. The Microwave Limb Sounder (MLS) on the Upper Atmosphere Research Satellite is able to retrieve water vapor concentration in the upper troposphere with good sensitivity and nearly global coverage. An analysis of these preliminary retrievals based on 3 years of observations shows the water vapor distribution to be similar to that measured by other techniques and to model results. The primary MLS water vapor measurements were made in the stratosphere, where this species acts as a conserved tracer under certain conditions. As is the case for the upper troposphere, most of the stratospheric discussion focuses on the time evolution of the zonal mean and zonally varying water vapor. Stratospheric results span a 19-month period and tropospheric results a 36-month period, both beginning in October of 1991. Comparisons with stratospheric model calculations show general agreement, with some differences in the amplitude and phase of long-term variations. At certain times and places, the evolution of water vapor distributions in the lower stratosphere suggests the presence of meridional transport.

  11. Optical Sensor for Diverse Organic Vapors at ppm Concentration Ranges

    Directory of Open Access Journals (Sweden)

    Dora M. Paolucci

    2011-03-01

    Full Text Available A broadly responsive optical organic vapor sensor is described that responds to low concentrations of organic vapors without significant interference from water vapor. Responses to several classes of organic vapors are highlighted, and trends within classes are presented. The relationship between molecular properties (vapor pressure, boiling point, polarizability, and refractive index and sensor response are discussed.

  12. Education for Making Meaning

    Science.gov (United States)

    Nash, Robert J.; Jang, Jennifer J. J.

    2014-01-01

    This chapter explains the meaning of meaning-making for the quarterlife generation. It describes what is called the meaning-quest--consisting of nine core meaning-making questions--and offers two examples of the pedagogy that the authors use in working with students.

  13. Comparison of short- with long-term regeneration results after digital nerve reconstruction with muscle-in-vein conduits

    Directory of Open Access Journals (Sweden)

    Jennifer Lynn Schiefer

    2015-01-01

    Full Text Available Muscle-in-vein conduits are used alternatively to nerve grafts for bridging nerve defects. The purpose of this study was to examine short- and long-term regeneration results after digital nerve reconstruction with muscle-in-vein conduits. Static and moving two-point discriminations and Semmes-Weinstein Monofilaments were used to evaluate sensory recovery 6-12 months and 14-35 months after repair of digital nerves with muscle-in-vein in 7 cases. Both follow-ups were performed after clinical signs of progressing regeneration disappeared. In 4 of 7 cases, a further recovery of both two-point discriminations and in another case of only the static two-point discrimination of 1-3 mm could be found between the short-term and long-term follow-up examination. Moreover, a late recovery of both two-point discriminations was demonstrated in another case. Four of 7 cases showed a sensory improvement by one Semmes-Weinstein Monofilaments. This pilot study suggests that sensory recovery still takes place even when clinical signs of progressing regeneration disappear.

  14. Experience on sheathing 10 km of cable-in-conduit conductor for the NHMFL 45-T hybrid

    International Nuclear Information System (INIS)

    The superconducting outsert magnet for the 45-T Hybrid Magnet System being constructed for the National High Magnetic Field Laboratory (NHMFL) in Tallahassee, Florida will contain almost 6.5 km of cable-in-conduit conductor (CICC) in three different grades. The project is a collaborative effort with the Francis Bitter National Magnet Laboratory (FBNML) and industry. Counting dummy CICCs manufactured during the development phase of the project and excesses for contingency, well over 10 km (over 11 MA-m) will have been produced. To fabricate these conductors, a special production line was assembled by the industrial team of Intermagnetics General Corporation (IGC) and Gibson Tube. Components in the line were adapted from modern cable-handling and welded-tube-manufacturing machinery, with the addition of a computer data-acquisition system for process monitoring. The versatility of the IGC/Gibson line has been demonstrated by the production of three different grades of CICC in which the external dimensions, wall thicknesses, corner radii, and even conduit alloy were variables. This paper describes special features and capabilities of the manufacturing line as well as production rates and tolerances achieved in the final product

  15. Mechanical tests of the conduit tubes of a conductor for the Toroidal winding of the International Thermonuclear Experimental Reactor (ITER)

    Science.gov (United States)

    Krivykh, A. V.; Anashkin, O. P.; Keilin, V. E.; Diev, D. N.; Dinisilov, A. S.; Shcherbakov, V. I.; Tronza, V. I.

    2012-11-01

    Extremely stringent requirements, which include the impact toughness at the liquid-helium temperature, are imposed on the material of the conduit tubes for International Thermonuclear Experimental Reactor (ITER) Toroidal Field (TF) conductors. Modified 316LN-IG stainless steel is recommended as the conduit tube material. Steel 316LN-IG tube samples (both full-size samples and sub-sized samples) are subjected to mechanical tests at various stages of the process of conductor production: in the as-recieved state and after compacting, preliminary elongation by 2.5% at room temperature, and annealing at 650°C for 200 h in a pure helium gas atmosphere. The tests are carried out at room, liquid nitrogen, and liquid helium temperatures and satisfy the standards of the American Society of Mechanical Engineers (ASME and ASTM). The results of sub-size and full-size samples testing show that the last one gives more representative results to qualify the weld joints in liquid nitrogen. When the temperature decreases or the strain increases, the magnetization of the samples increases, especially in the weld area. Strain measurements with an extensometer demonstrate that the intracrystal processes occurring at the liquid-helium temperature can lead to a significant change in the local load, up to complete unloading in a deformation zone. Unusual local serrated deformation is observed with an extensometer installed in the weld area during tests in liquid helium: this deformation is the result of compressive jumps opposite to the loading direction.

  16. Peritoneal Patch for an Occluded Venous Conduit of a Right Lobe During a Living-Donor Liver Transplant.

    Science.gov (United States)

    Kayaalp, Cuneyt; Abbasov, Parviz; Sabuncuoglu, Mehmet Zafer; Alam, Abdul Hamid; Yilmaz, Sezai

    2015-08-01

    Drainage of segments V and VIII venous tributaries usually is mandatory to avoid congestion of the anterior segment of right lobe during a living-donor liver transplant. Extension of the venous tributaries to the vena cava can be done with several vascular materials. Here, we describe using an 8 × 3 cm vascular patch from the peritoneum over the venous conduit (which had become kinked) that drained segments V and VIII veins. Peritoneal reconstruction worked well during the early postoperative period and avoided congestion of the right anterior liver segment. During the late postoperative period, the conduit became occluded as do other grafts used to extend tributaries; however, the collaterals that developed prevented congestion of the anterior liver segment. Using part of the peritoneum as a venous graft during living-donor liver transplant can be a good alternative to the other vascular grafting options. Peritoneal grafting provides temporary drainage of the liver lobe, prevents congestion of the anterior section, and saves time creating venous collaterals. PMID:25376026

  17. A 600-m jacketing line of cable-in-conduit conductor (CICC) and first 600-m dummy cable

    International Nuclear Information System (INIS)

    A cable-in-conduit 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 x 20.8 +- 0.1, 20.4 +- 0.1 x 20.4 +- 0.1 and 18.6 +- 0.1 x 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), conduits butt-welding, six kinds of quality checking (endoscopy, dye penetration, pressure control, leakage testing, ultrasonic inspection and X-ray testing), cable inserting, shaping (compacting and squaring), pre-bending and 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

  18. Comparison of short- with long-term regeneration results after digital nerve reconstruction with muscle-in-vein conduits.

    Science.gov (United States)

    Schiefer, Jennifer Lynn; Schulz, Lukas; Rath, Rebekka; Stahl, Stéphane; Schaller, Hans-Eberhard; Manoli, Theodora

    2015-10-01

    Muscle-in-vein conduits are used alternatively to nerve grafts for bridging nerve defects. The purpose of this study was to examine short- and long-term regeneration results after digital nerve reconstruction with muscle-in-vein conduits. Static and moving two-point discriminations and Semmes-Weinstein Monofilaments were used to evaluate sensory recovery 6-12 months and 14-35 months after repair of digital nerves with muscle-in-vein in 7 cases. Both follow-ups were performed after clinical signs of progressing regeneration disappeared. In 4 of 7 cases, a further recovery of both two-point discriminations and in another case of only the static two-point discrimination of 1-3 mm could be found between the short-term and long-term follow-up examination. Moreover, a late recovery of both two-point discriminations was demonstrated in another case. Four of 7 cases showed a sensory improvement by one Semmes-Weinstein Monofilaments. This pilot study suggests that sensory recovery still takes place even when clinical signs of progressing regeneration disappear. PMID:26692868

  19. Atomic vapor laser isotope separation

    International Nuclear Information System (INIS)

    Atomic vapor laser isotope separation (AVLIS) is a general and powerful technique. A major present application to the enrichment of uranium for light-water power reactor fuel has been under development for over 10 years. In June 1985 the Department of Energy announced the selection of AVLIS as the technology to meet the nation's future need for the internationally competitive production of uranium separative work. The economic basis for this decision is considered, with an indicated of the constraints placed on the process figures of merit and the process laser system. We then trace an atom through a generic AVLIS separator and give examples of the physical steps encountered, the models used to describe the process physics, the fundamental parameters involved, and the role of diagnostic laser measurements

  20. Soil vapor extraction with dewatering

    Energy Technology Data Exchange (ETDEWEB)

    Thomson, N.R. [Univ. of Waterloo, Ontario (Canada)

    1996-08-01

    The physical treatment technology of soil vapor extraction (SVE) is reliable, safe, robust, and able to remove significant amounts of mass at a relatively low cost. SVE combined with a pump-and-treat system to create a dewatered zone has the opportunity to remove more mass with the added cost of treating the extracted groundwater. Various limiting processes result in a significant reduction in the overall mass removal rates from a SVE system in porous media. Only pilot scale, limited duration SVE tests conducted in low permeability media have been reported in the literature. It is expected that the presence of a fracture network in low permeability media will add another complexity to the limiting conditions surrounding the SVE technology. 20 refs., 4 figs.

  1. Internalized Meaning Factualism

    DEFF Research Database (Denmark)

    Hohwy, Jakob

    2006-01-01

    defended by, e.g., Robert Brandom, Paul Horwich and Huw Price), that promises to solve the problems. According to this position, the problem of meaning can be solved by prohibiting an external perspective on meaning constituting properties. The idea is that if we stick to a perspective on meaning that is......The normative character of meaning creates deep problems for the attempt to give a reductive explanation of the constitution of meaning. I identify and critically examine an increasingly popular Carnap-style position, which I call Internalized Meaning Factualism (versions of which I argue are...... internal to meaning discourse, then we can preserve the normativity of meaning and yet locate meaning in the natural world. I develop a generic motivation for this position, but argue that, since this motivation is consistent with the Ramsey-Carnap-Lewis-Jackson reductionist strategy, internalized meaning...

  2. Meanings of Materials:

    OpenAIRE

    Karana, E.

    2009-01-01

    This book is about meanings we attribute to materials of the objects around us. Materials convey meanings: they look traditional, they express luxury, they are associated with factories, or they conjure up one’s childhood. How do materials obtain these meanings? How do they interact with other elements of product design in expressing certain meanings? How can designers systematically incorporate meaning considerations into their materials selection processes? This book presents...

  3. Risk assessment of metal vapor arcing

    Science.gov (United States)

    Hill, Monika C. (Inventor); Leidecker, Henning W. (Inventor)

    2009-01-01

    A method for assessing metal vapor arcing risk for a component is provided. The method comprises acquiring a current variable value associated with an operation of the component; comparing the current variable value with a threshold value for the variable; evaluating compared variable data to determine the metal vapor arcing risk in the component; and generating a risk assessment status for the component.

  4. Vapor sampling and analysis plan. Revision 1

    International Nuclear Information System (INIS)

    This document is a plan which serves as the contractual agreement between the Characterization Program, Sampling Operations, Oak Ridge National Laboratory, and PNL tank vapor program. The scope of this plan is to provide guidance for the sampling and analysis of vapor samples from both SST and DST tanks

  5. The trigger mechanism of vapor explosion

    International Nuclear Information System (INIS)

    In the present study, trigger mechanisms of the vapor explosion are experimentally investigated. The interfacial behavior between high temperature molten liquid and low temperature water are experimentally investigated by using a molten material droplet and external pressure pulse. As the results, it is indicated that spontaneous vapor explosion hardly occur in high temperature water near saturation temperature since vapor film is stable. The vapor explosion can occur even in high temperature water near saturation temperature in case that the external pressure pulse is applied to high temperature molten material. Vapor explosion can not occur when the interfacial temperature between the molten material and water is lower than the material melting temperature, even if the vapor film around the molten material is collapsed by the external pressure pulse. It is clarified that the impossibility of the trigger process for the vapor explosion can be judged by comparing the interfacial temperature and the molten material temperature. The results obtained in the present experiments are applied to the results of the large-scale experiments using uranium dioxide. The results indicate that the possibility of the vapor explosion of the uranium dioxide and water under the present LWR operational condition is extremely unlikely. It should be noted that the preset criteria should be applicable in case that the melting temperature does not decrease by containing the metal component. (author)

  6. Tower Water-Vapor Mixing Ratio

    Energy Technology Data Exchange (ETDEWEB)

    Guastad, Krista; Riihimaki, Laura; none,

    2013-04-01

    The purpose of the Tower Water-Vapor Mixing Ratio (TWRMR) value-added product (VAP) is to calculate water-vapor mixing ratio at the 25-meter and 60-meter levels of the meteorological tower at the Southern Great Plains (SGP) Central Facility.

  7. High bandwidth vapor density diagnostic system

    Science.gov (United States)

    Globig, Michael A. (Antioch, CA); Story, Thomas W. (Oakley, CA)

    1992-01-01

    A high bandwidth vapor density diagnostic system for measuring the density of an atomic vapor during one or more photoionization events. The system translates the measurements from a low frequency region to a high frequency, relatively noise-free region in the spectrum to provide improved signal to noise ratio.

  8. Platform-to-platform sample transfer, distribution, dilution, and dosing via electrothermal vaporization and electrostatic deposition

    CERN Document Server

    Hermann, G; Matz, R; Gafurov, M; Gilmutdinov, A; Nagulin, K; Frech, W; Bjoern, E; Grinshtein, I; Vasilieva, L

    2004-01-01

    A novel system for solid sample pretreatment, handling, and dosing for analytical atomic spectrometry is described. A primary solid or liquid sample is vaporized in a graphite furnace and then condensed in a specially designed condensation zone. On the further transport path, the analyte aerosol can be diluted and distributed in pre-set ratios. Applying a corona discharge, aerosol particulates are then quantitatively re-collected by means of intra-furnace electrostatic precipitation on the platform of another graphite furnace or by external precipitation on one or a set of platforms. Furthermore, the described procedure allows external thermal sample pretreatment with preceding pyrolysis and additional vaporization, condensation, and re-precipitation that significantly reduces or removes the sample matrix. Owing to different losses, transport efficiencies of electrothermal vaporization (ETV) instrumentation depend on analyte element, matrix, vaporization temperature, ramp rate, and tube history. In order to r...

  9. Global monitoring of tropospheric water vapor with GPS radio occultation aboard CHAMP

    CERN Document Server

    Heise, S; Beyerle, G; Schmidt, T; Reigber, C

    2005-01-01

    The paper deals with application of GPS radio occultation (RO) measurements aboard CHAMP for the retrieval of tropospheric water vapor profiles. The GPS RO technique provides a powerful tool for atmospheric sounding which requires no calibration, is not affected by clouds, aerosols or precipitation, and provides an almost uniform global coverage. We briefly overview data processing and retrieval of vertical refractivity, temperature and water vapor profiles from GPS RO observations. CHAMP RO data are available since 2001 with up to 200 high resolution atmospheric profiles per day. Global validation of CHAMP water vapor profiles with radiosonde data reveals a bias of about 0.2 g/kg and a standard deviation of less than 1 g/kg specific humidity in the lower troposphere. We demonstrate potentials of CHAMP RO retrievals for monitoring the mean tropospheric water vapor distribution on a global scale.

  10. Variation characteristics of water vapor distribution during 2000-2008 over Hefei (31.9°N, 117.2°E) observed by L625 lidar

    Science.gov (United States)

    Wang, Min; Fang, Xin; Hu, Shunxing; Hu, Huanling; Li, Tao; Dou, Xiankang

    2015-10-01

    Observations of monthly and seasonal nightly water vapor variations over Hefei utilizing L625 lidar water vapor data observed from 2000 to 2008 is the focus of this study. The experimental setup and main parameters of the L625 lidar for water vapor measurement are first presented, then the measurement principle of water vapor and data processing methods are introduced. The water vapor measurement precision of the lidar system was analyzed by comparison with radiosonde. Monthly and seasonal water vapor profiles were built by analyzing 2000-2008 lidar data. In the vertical direction, results show that water vapor content decreases gradually with height. The more the water vapor content in the low atmosphere, the faster the decay rate with altitude. As far as monthly variation, the water vapor content first increases and then decreases with month. The maximum content of water vapor appears in July, at mixing ratio of 15.6 g/kg at 1 km. The seasonal variability of water vapor content is rather obvious. In summer the water vapor mixing ratio reaches up to 15.0 g/kg at 1 km, and in winter it is only 3.9 g/kg at the same altitude. Interannual variation of water vapor content differs between seasons (as revealed in the standard deviation of data) where summer is least stable and autumn is the most stable. Precipitable water vapor is calculated from water vapor mean profiles at 1-4 km and the relationship between precipitable water vapor and precipitation is also investigated. A clear positive correlation is found with Pearson correlation coefficients (R) 0.933 between monthly precipitation and mean precipitable water vapor, as well a clear positive correlation between seasonal precipitation and seasonal mean precipitable water vapor (R = 0.988). Precipitation conversion efficiency (PCE) is calculated from precipitation and precipitable water vapor. The monthly PCE reaches its maximum in October at 25.8%, and drops to its minimum in January at 11.5%. Seasonal PCE's minimum is 15.2% in autumn and 23.7% in winter, at maximum.

  11. Biodegradable chitin conduit tubulation combined with bone marrow mesenchymal stem cell transplantation for treatment of spinal cord injury by reducing glial scar and cavity formation

    Directory of Open Access Journals (Sweden)

    Feng Xue

    2015-01-01

    Full Text Available We examined the restorative effect of modified biodegradable chitin conduits in combination with bone marrow mesenchymal stem cell transplantation after right spinal cord hemisection injury. Immunohistochemical staining revealed that biological conduit sleeve bridging reduced glial scar formation and spinal muscular atrophy after spinal cord hemisection. Bone marrow mesenchymal stem cells survived and proliferated after transplantation in vivo, and differentiated into cells double-positive for S100 (Schwann cell marker and glial fibrillary acidic protein (glial cell marker at 8 weeks. Retrograde tracing showed that more nerve fibers had grown through the injured spinal cord at 14 weeks after combination therapy than either treatment alone. Our findings indicate that a biological conduit combined with bone marrow mesenchymal stem cell transplantation effectively prevented scar formation and provided a favorable local microenvironment for the proliferation, migration and differentiation of bone marrow mesenchymal stem cells in the spinal cord, thus promoting restoration following spinal cord hemisection injury.

  12. Microbial growth with vapor-phase substrate

    International Nuclear Information System (INIS)

    Limited information exists on influences of the diffusive transport of volatile organic contaminants (VOC) on bacterial activity in the unsaturated zone of the terrestrial subsurface. Diffusion of VOC in the vapor-phase is much more efficient than in water and results in effective VOC transport and high bioavailability despite restricted mobility of bacteria in the vadose zone. Since many bacteria tend to accumulate at solid-water, solid-air and air-water interfaces, such phase boundaries are of a special interest for VOC-biodegradation. In an attempt to evaluate microbial activity toward air-borne substrates, this study investigated the spatio-temporal interplay between growth of Pseudomonas putida (NAH7) on vapor-phase naphthalene (NAPH) and its repercussion on vapor-phase NAPH concentrations. Our data demonstrate that growth rates of strain PpG7 were inversely correlated to the distance from the source of vapor-phase NAPH. Despite the high gas phase diffusivity of NAPH, microbial growth was absent at distances above 5 cm from the source when sufficient biomass was located in between. This indicates a high efficiency of suspended bacteria to acquire vapor-phase compounds and influence headspace concentration gradients at the centimeter-scale. It further suggests a crucial role of microorganisms as biofilters for gas-phase VOC emanating from contaminated groundwater or soil. - Research highlights: ? Suspended bacteria have a high efficiency to degrade vapor-phase naphthalene. ? Bacteria influence NAPH vapor-phase concentration gradients at centimeter-scale. ? Microbial growth on vapor-phase naphthalene is inversely correlated to its source. ? Bacteria are good biofilters for gas-phase NAPH emanating from contaminated sites. - Suspended bacteria have a high efficiency to degrade vapor-phase naphthalene and effectively influence vapor-phase naphthalene concentration gradients at the centimeter scale.

  13. HANFORD CHEMICAL VAPORS WORKER CONCERNS & EXPOSURE EVALUATION

    Energy Technology Data Exchange (ETDEWEB)

    ANDERSON, T.J.

    2006-12-20

    Chemical vapor emissions from underground hazardous waste storage tanks on the Hanford site in eastern Washington State are a potential concern because workers enter the tank farms on a regular basis for waste retrievals, equipment maintenance, and surveillance. Tank farm contractors are in the process of retrieving all remaining waste from aging single-shell tanks, some of which date to World War II, and transferring it to newer double-shell tanks. During the waste retrieval process, tank farm workers are potentially exposed to fugitive chemical vapors that can escape from tank headspaces and other emission points. The tanks are known to hold more than 1,500 different species of chemicals, in addition to radionuclides. Exposure assessments have fully characterized the hazards from chemical vapors in half of the tank farms. Extensive sampling and analysis has been done to characterize the chemical properties of hazardous waste and to evaluate potential health hazards of vapors at the ground surface, where workers perform maintenance and waste transfer activities. Worker concerns. risk communication, and exposure assessment are discussed, including evaluation of the potential hazards of complex mixtures of chemical vapors. Concentrations of vapors above occupational exposure limits-(OEL) were detected only at exhaust stacks and passive breather filter outlets. Beyond five feet from the sources, vapors disperse rapidly. No vapors have been measured above 50% of their OELs more than five feet from the source. Vapor controls are focused on limited hazard zones around sources. Further evaluations of vapors include analysis of routes of exposure and thorough analysis of nuisance odors.

  14. Application of atmospheric CVD for internal surface coating of graphite conduit by silicon carbide

    International Nuclear Information System (INIS)

    Highlights: • APCVD could be a suitable process for SiC coating on complex geometry. • Dendrite structure of SiC was observed along the axis. • SiC coating was boundary phenomena. • Uniform coating was observed along axial and radial direction. - Abstract: Mechanism of silicon carbide coating on the internal surface of the graphite tube of dimension ? 3 mm ID × ? 10 mm OD × ? 235 mm and surface area ?24.5 cm2 has been investigated. Atmospheric pressure chemical vapor deposition (APCVD) method in mass controlled domain has been applied. Methyltrichlorosilane (MTS) as precursor was used in the present investigation. The coating was characterized by X-ray micro tomography (?CT). The coating thickness and composition were analyzed by scanning electron microscopy energy-dispersive spectroscopy (SEM–EDS). The coating phase analyzed by X-ray diffraction (XRD). It has been concluded that silicon carbide coating is a predominantly boundary layer phenomena and the engineering of the same could open up the prospects to accomplish SiC coating on complex pipe line structures on macro scale

  15. Application of atmospheric CVD for internal surface coating of graphite conduit by silicon carbide

    Energy Technology Data Exchange (ETDEWEB)

    Rao, P.T. [Powder Metallurgy Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Jain, U. [Fusion Reactor Materials Section, Bhabha Atomic Research Centre, Mumbai 400085 (India); Mollick, P.K. [Powder Metallurgy Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Agarwal, A. [Neutron and X-ray Physics Facilities, Bhabha Atomic Research Centre, Mumbai 400085 (India); Chakravartty, J.K. [Powder Metallurgy Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kumar, Sanjay, E-mail: sanjay.barc@gmail.com [Fusion Reactor Materials Section, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2015-01-15

    Highlights: • APCVD could be a suitable process for SiC coating on complex geometry. • Dendrite structure of SiC was observed along the axis. • SiC coating was boundary phenomena. • Uniform coating was observed along axial and radial direction. - Abstract: Mechanism of silicon carbide coating on the internal surface of the graphite tube of dimension ? 3 mm ID × ? 10 mm OD × ? 235 mm and surface area ?24.5 cm{sup 2} has been investigated. Atmospheric pressure chemical vapor deposition (APCVD) method in mass controlled domain has been applied. Methyltrichlorosilane (MTS) as precursor was used in the present investigation. The coating was characterized by X-ray micro tomography (?CT). The coating thickness and composition were analyzed by scanning electron microscopy energy-dispersive spectroscopy (SEM–EDS). The coating phase analyzed by X-ray diffraction (XRD). It has been concluded that silicon carbide coating is a predominantly boundary layer phenomena and the engineering of the same could open up the prospects to accomplish SiC coating on complex pipe line structures on macro scale.

  16. The experimental liquid-vapor phase diagram of bulk nuclear matter

    Science.gov (United States)

    Moretto, L. G.; Elliott, J. B.; Phair, L.; Lake, P. T.

    2011-11-01

    The modern investigation of clusters, for which 1 Lt N Lt ?, requires a generalization of the thermodynamics developed for infinite systems. For instance, in finite systems, phase transitions and phase coexistence become ill-defined with ambiguous signals. The existence of phase transitions in nuclear systems, in particular of the liquid-vapor kind, has been widely discussed and even experimentally claimed. A consistent and unambiguous approach to this problem requires a connection between finite systems and the corresponding infinite systems. Historically, this has been achieved at temperature T = 0 by the introduction of the liquid drop model and the extraction of the volume term, which is a fundamental quantity of nuclear matter. This work extends this approach to T > 0, by determining the liquid-vapor coexistence line and its termination at the critical point. Since there is no known experimental situation where a nuclear liquid and vapor are in coexistence, we establish a relationship between evaporation rates and saturated vapor concentration and characterize the saturated vapor with Fisher's droplet model. We validate this approach by analyzing cluster concentrations in the Ising and Lennard-Jones models and extracting the corresponding first-order coexistence line and critical temperature. Since the vapor of clusters coexists with a finite liquid drop, we devise a finite size correction leading to a modified Fisher equation. The application of the above techniques to nuclear systems requires dealing also with the Coulomb force. Nuclear cluster evaporation rates can be corrected for Coulomb effects and can be used to evaluate the cluster concentrations in the 'virtual' equilibrium vapor. These cluster concentrations, determined over a wide temperature range, can be analyzed by means of a modified Fisher formula. This leads to the extraction of the entire liquid-vapor coexistence line terminating at the critical point. A large body of experimental data has been analyzed in this manner and the liquid-vapor phase diagram of nuclear matter has been extracted.

  17. 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.

    Science.gov (United States)

    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 conduits in the field of nerve tissue engineering. PMID:25580010

  18. Lattice Boltzmann simulation of solute transport in heterogeneous porous media with conduits to estimate macroscopic continuous time random walk model parameters

    Energy Technology Data Exchange (ETDEWEB)

    Anwar, S.; Cortis, A.; Sukop, M.

    2008-10-20

    Lattice Boltzmann models simulate solute transport in porous media traversed by conduits. Resulting solute breakthrough curves are fitted with Continuous Time Random Walk models. Porous media are simulated by damping flow inertia and, when the damping is large enough, a Darcy's Law solution instead of the Navier-Stokes solution normally provided by the lattice Boltzmann model is obtained. Anisotropic dispersion is incorporated using a direction-dependent relaxation time. Our particular interest is to simulate transport processes outside the applicability of the standard Advection-Dispersion Equation (ADE) including eddy mixing in conduits. The ADE fails to adequately fit any of these breakthrough curves.

  19. Water Vapor Absorption in Early M-type Stars

    CERN Document Server

    Matsuura, M; Murakami, H; Freund, M M; Tanaka, M

    1999-01-01

    The spectrometers onboard the Infrared Telescope in Space (IRTS) reveal water vapor absorption in early M-type stars, as early as M2. Previous observations detected H_2O vapor absorption only in stars later than M6, with the exception of the recent detection of H_2O in beta Peg (M2.5 II-III). In our sample of 108 stars, 67 stars have spectral types earlier than M6. The spectral types are established by means of their near-infrared colors on a statistical basis. Among the 67 stars of spectral types earlier than M6, we find water vapor absorption in six stars. The observed absorption features are interpreted using a local thermodynamic equilibrium model. The features are reasonably fitted by model spectra with excitation temperatures of 1000-1500 K and water column densities of 5x10^19 to 1x10^20 cm^-2. These numbers imply that the H_2O molecules are present in a region of the atmosphere, located above the photosphere. Furthermore, our analysis shows a good correlation between the H_2O absorption band strength,...

  20. Simulation of stratospheric water vapor and trends using three reanalyses

    Directory of Open Access Journals (Sweden)

    M. R. Schoeberl

    2012-03-01

    Full Text Available The domain-filling, forward trajectory calculation model developed by Schoeberl and Dessler (2011 is extended to the 1979–2010 period. We compare results from NASA's MERRA, NCEP's CFSR, and ECMWF's ERAi reanalyses with HALOE, MLS, and balloon observations. The CFSR based simulation produces a wetter stratosphere than MERRA, and ERAi produces a drier stratosphere than MERRA. We find that ERAi temperatures are cold biased compared to Singapore sondes and MERRA, which explains the ERAi result, and the CFSR grid does not resolve the cold point tropopause, which explains its relatively higher water vapor concentration. The pattern of dehydration locations is also different among the three reanalyses. ERAi dehydration pattern stretches across the Pacific while CFSR and MERRA are concentrate dehydration activity in the West Pacific. CSFR and ERAi also show less dehydration activity in the West Pacific Southern Hemisphere than MERRA. The models' lower stratospheres tend to be dry at high northern latitudes because of too little methane-derived water appears to be descending from the middle stratosphere. Using the tropical tape recorder signal, we find that MERRA vertical ascent is 15% too weak while ERAi is 30% too strong. The models tend to reproduce the observed weakening of the 100-hPa annual cycle in zonal mean water vapor as it propagates to middle latitudes. Finally, consistent with the observations, the models show less than 0.2 ppm decade?1 trends in water vapor both at mid-latitudes and in the tropics.

  1. Tratamento percutâneo de lesões residuais e complicações em condutos de pacientes submetidos a cirurgia de circuito do tipo Fontan / Percutaneous treatment of residual lesions and complications in conduits following Fontan procedure

    Scientific Electronic Library Online (English)

    João Luiz, Manica; André Luis, Bodini; Paulo Renato, Machado; Mônica Scott, Borges; Raul Ivo, Rossi Filho.

    Full Text Available INTRODUÇÃO: A introdução da cirurgia de anastomose cavopulmonar total (ACPT) ou cirurgia de Fontan modificou de forma significativa a história natural de pacientes com cardiopatias complexas não passíveis de reparo biventricular. Entretanto, é conhecido o desenvolvimento de estenoses silenciosas. Al [...] ém disso, a utilização de condutos fenestrados é uma técnica comumente realizada. O presente estudo relata a experiência de um centro terciário no implante percutâneo de dispositivos em condutos de pacientes com circulação do tipo univentricular. MÉTODO: Entre julho de 2000 e julho de 2010, 12 pacientes receberam dispositivos percutâneos em condutos após cirurgia de Fontan. Os pacientes foram divididos em dois grupos, de acordo com a indicação para o procedimento: 5 pacientes receberam implante de oclusores septais para fechamento de fenestração cirúrgica (grupo 1), 6 pacientes receberam stents para alívio de obstrução de condutos (grupo 2), e 1 paciente recebeu ambos os dispositivos simultaneamente. A média de idade dos pacientes do grupo 1 no momento do procedimento era de 174 ± 53,5 meses e o peso médio era de 30,7 ± 6,8 kg. A média de idade dos pacientes do grupo 2 no momento do procedimento era de 148,5 ± 84,6 meses e o peso médio era de 28,9 ± 19,8 kg. RESULTADOS: No grupo 1, a saturação média passou de 82,6 ± 7,5% para 90,4 ± 7,5% logo após o procedimento (P = 0,001). No grupo 2, a saturação média passou de 81,8 ± 8,9% para 91,3 ± 8,7% (P = 0,01). O menor diâmetro do conduto passou de uma média de 6,9 ± 4,8 mm para 16,6 ± 3,5 mm após o procedimento (P = 0,02). O paciente que realizou ambos os procedimentos simultaneamente teve aumento do menor diâmetro do conduto de 11,7 mm para 16 mm e melhora da saturação sistêmica, passando de 60% para 90%. CONCLUSÃO: O tratamento da obstrução de condutos por meio do implante de stents não-recobertos e a oclusão de fenestrações cirúrgicas com stents recobertos ou dispositivos de AmplatzerTM são procedimentos seguros, com altos índices de sucesso imediato e que se mantêm a médio prazo. Abstract in english BACKGROUND: The introduction of total cavopulmonary anastomosis (TCPA) or Fontan procedure significantly changed the natural history of patients with complex heart diseases inadequate for biventricular repair. However, the development of silent stenosis is well known. In addition, fenestrated condui [...] ts are frequently used. The present study reports the experience of a tertiary center with percutaneous devices implanted in the conduits of patients with univentricular circulation. METHOD: From July 2000 to July 2010, 12 patients received percutaneous devices in conduits after Fontan procedure. Patients were divided into two groups, according to the indication for the procedure: 5 patients received septal occluders to close surgical fenestrations (group 1), 6 patients received stents for the relief of conduit obstructions (group 2) and 1 patient received both devices simultaneously. Mean age of group 1 patients at the time of the procedure was 174 ± 53.5 months and mean weight was 30.7 ± 6.8 kg. Mean age of group 2 patients was 148.5 ± 84.6 months and mean weight was 28.9 ± 19.8 kg. RESULTS: In group 1, oxygen saturation rose from 82.6 ± 7.5% to 90.4 ± 7.5% immediately after the procedure (P = 0.001). In group 2, oxygen saturation rose from 81.8 ± 8.9% to 91.3 ± 8.7% (P = 0.01). The minimal conduit diameter changed from 6.9 + 4,8 mm to 16.6 ± 3.5 mm after the procedure (P = 0.02). The patient who was submitted to both procedures simultaneously had an increase of the minimal conduit diameter from 11.7 mm to 16 mm and an improvement in systemic saturation from 60% to 90%. CONCLUSION: Treatment of conduit obstructions with non-covered stents and the occlusion of surgical fenestrations with covered stents or AmplatzerTM devices are safe procedures, with high immediate success rates which are maintained in the mid-term follow-up.

  2. Darwinism and the meaning of ‘meaning

    Directory of Open Access Journals (Sweden)

    Castrodeza, Carlos

    2009-12-01

    Full Text Available The problem of the meaning of life is herewith contemplated from a Darwinian perspective. It is argued how factors such as existential depression, the concern about the meaning of ‘meaning’, the problem of evil, death as the end of our personal identity, happiness as an unachievable goal, etc. may well have an adaptive dimension ‘controlled’ neither by ourselves nor obscure third parties (conspiracy theories but ‘simply’ by our genes (replicators in general so that little if anything is to be done to find a radical remedy for the human condition.

    El problema del sentido de la existencia se contempla en estas páginas desde una perspectiva darwiniana. Se argumenta como factores tales como la depresión existencial, la preocupación acerca del sentido del ‘sentido’, el problema del mal, la muerte como fin de nuestra identidad personal, la felicidad como meta inalcanzable, etc. pueden tener una dimensión adaptativa que no está ‘controlada’ ni por nosotros ni por terceras partes (teorías de la conspiración sino ‘simplemente’ por nuestros genes (replicadores en general de modo que nada o más bien poco se puede hacer para remediar en profundidad la condición humana.

  3. Meaning in mathematics education

    CERN Document Server

    Kilpatrick, Jeremy; Skovsmose, Ole

    2006-01-01

    What does it mean to know mathematics? How does meaning in mathematics education connect to common sense or to the meaning of mathematics itself? How are meanings constructed and communicated and what are the dilemmas related to these processes? There are many answers to these questions, some of which might appear to be contradictory. Thus understanding the complexity of meaning in mathematics education is a matter of huge importance. There are twin directions in which discussions have developed - theoretical and practical - and this book seeks to move the debate forward along both dimensions

  4. Assessment of water vapor content from MIVIS TIR data

    Directory of Open Access Journals (Sweden)

    V. Tramutoli

    2006-06-01

    Full Text Available The main objective of land remotely sensed images is to derive biological, chemical and physical parameters by inverting sample sets of spectral data. For the above aim hyperspectral scanners on airborne platform are a powerful remote sensing instrument for both research and environmental applications because of their spectral resolution and the high operability of the platform. Fine spectral information by MIVIS (airborne hyperspectral scanner operating in 102 channels ranging from VIS to TIR allows researchers to characterize atmospheric parameters and their effects on measured data which produce undesirable features on surface spectral signatures. These effects can be estimated (and remotely sensed radiances corrected if atmospheric spectral transmittance is known at each image pixel. Usually ground-based punctual observations (atmospheric sounding balloons, sun photometers, etc. are used to estimate the main physical parameters (like water vapor and temperature profiles which permit us to estimate atmospheric spectral transmittance by using suitable radiative transfer model and a specific (often too strong assumption which enable atmospheric properties measured only in very few points to be extended to the whole image. Several atmospheric gases produce observable absorption features, but only water vapor strongly varies in time and space. In this work the authors customize a self-sufficient «split-window technique» to derive (at each image pixel atmospheric total columnar water vapor content (TWVC using only MIVIS data collected by the fourth MIVIS spectrometer (Thermal Infrared band. MIVIS radiances have been simulated by means of MODTRAN4 radiative transfer code and the coefficients of linear regression to estimate TWVC from «split-windows» MIVIS radiances, based on 450 atmospheric water vapor profiles obtained by radiosonde data provided by NOAANESDIS. The method has been applied to produce maps describing the spatial variability of the water vapor columnar content along a trial scene. The procedure has been validated by means of the MIVIS data acquired over Venice and the contemporary radiosonde data. A discrepancy within 5% has been measured between the estimate of TWVC derived from the proposed self-sufficient split-window technique and the coincident radiosonde measurements. If confirmed by further analyses such a result will permit us to fully exploit MIVIS TIR capability to offer a more effective (at image pixel level and self-sufficient (no ancillary observations required way to obtain atmospherically corrected MIVIS radiances.

  5. Study on trigger mechanism of vapor explosion

    Energy Technology Data Exchange (ETDEWEB)

    Nariai, H.; Abe, Y.; Hamada, Y.; Yanagida, H.; Tochio, D. [Tsukuba Univ., Institute of Engineering Mechanics and systems, Ibaraki (Japan)

    2001-07-01

    During severe accident of a light water reactor, various thermal hydraulic phenomena including vapor explosion could threaten the integrity of the containment vessel. The occurrence of the severe accident is extremely unlikely since LWRs are designed based on the defense-in-depth concept. However, it is important to investigate the thermal hydraulic phenomena including vapor explosion in order to evaluate the safety margin and potential risks of the accident management measures to prevent and mitigate the severe accident. Thermal detonation model is proposed to describe the vapor explosion. (author)

  6. Study on trigger mechanism of vapor explosion

    International Nuclear Information System (INIS)

    During severe accident of a light water reactor, various thermal hydraulic phenomena including vapor explosion could threaten the integrity of the containment vessel. The occurrence of the severe accident is extremely unlikely since LWRs are designed based on the defense-in-depth concept. However, it is important to investigate the thermal hydraulic phenomena including vapor explosion in order to evaluate the safety margin and potential risks of the accident management measures to prevent and mitigate the severe accident. Thermal detonation model is proposed to describe the vapor explosion. (author)

  7. Isotopic equilibrium between precipitation and water vapor: evidence from continental rains in central Kenya

    Science.gov (United States)

    Soderberg, K.; Gerlein, C.; Kemeny, P. C.; Caylor, K. K.

    2013-12-01

    An accurate understanding of the relationships between the isotopic composition of liquid water and that of water vapor in the environment can help describe hydrologic processes across many scales. One such relationship is the isotopic equilibrium between falling raindrops and the surrounding vapor. The degree of equilibration is used to model the isotopic composition of precipitation in isotope-enable general circulation models and land-atmosphere exchange models. Although this equilibrium has been a topic of isotope hydrology research for more than four decades, few studies have included vapor measurements to validate modeling efforts. Recent advances in laser technology have allowed for in situ vapor measurements at high temporal resolution (e.g., >1 Hz). Here we present concomitant rain and vapor measurements for a series of 17 rain events during the 'Continental' rainy season (June through August) at Mpala Research Center in central Kenya. Rain samples (n=218) were collected at intervals of 2 to 35 minutes (median of 3 minutes) depending on the rain rate (0.4 to 10.5 mm/hr). The volume-weighted mean rain values for ?18O, ?2H and D-excess (?2H - 8* ?18O) were 0.1 ‰, 10.7 ‰, and 10.1 ‰. These values are more enriched than the annual weighted means reported for the area (-2.2 ‰, -7.6 ‰, and 11.0 ‰, respectively). Vapor was measured continuously at ~2Hz (DLT-100, Los Gatos Research), with an inverted funnel intake 4m above the ground surface. The mean vapor isotopic composition during the rain events was -10.0 +/- 1.2 ‰ (1 ?) for ?18O and -73.9 +/- 7.0 ‰ for ?2H. The difference between the rain sample isotopic composition and that of liquid in isotopic equilibrium with the corresponding vapor at the ambient temperature was 0.8 +/- 2.2 ‰ for ?18O and 6.2 +/- 7.0 ‰ for ?2H. This disequilibrium was found to correlate with the natural log of rain rate (R2 of 0.26 for ?18O and 0.46 for ?2H), with lower rain rates having larger disequilibrium. There was also a temporal pattern in the disequilibrium for ?18O, with the first five rain events having significantly larger (p < 0.01) disequilibrium (4.4 ‰) than the subsequent rain events (0.6 ‰). The temporal pattern suggests that, in addition to the relationship with rain rate, there is some relationship between rain-vapor equilibrium and larger-scale controls such as vapor source region, precipitation recycling and air mass trajectory.

  8. Transcatheter pulmonary valve insertion, expanded use (beyond large conduits from the right ventricle to pulmonary artery), and future directions.

    Science.gov (United States)

    Ringewald, Jeremy M; Suh, Elsa J

    2014-12-01

    Transcatheter pulmonary valve insertion is the most important advance in congenital interventional cardiology since atrial septal defect devices became commonly available 15 years ago. It has changed the way we look at a number of diverse diagnoses and changes how we plan, diagnose, operate, and follow-up patients. It has changed how we counsel families expecting a child that may benefit from it. Expanded use of the Melody® valve, outside its United States Food and Drug Administration approved indications, has helped numerous additional patients. The use of transcatheter pulmonary valve insertion in selected patients following surgical Gore-tex® bileaflet in valve right ventricular outflow tract reconstruction and those with a history of prior small homograft conduits will be discussed. PMID:25647384

  9. Comparaison des conduites discursives de mères et d’enseignants dans la co-construction de récits avec des enfants

    Directory of Open Access Journals (Sweden)

    Vinel Elise

    2014-07-01

    Full Text Available Cette communication s’intéresse aux conduites discursives produites par des mères et des enseignants au cours de deux lectures conjointes d’album avec des enfants. Elle s’inscrit dans une approche dialogique et interactionniste du langage. Dans la suite des travaux de Florin (1991, Grossmann (1996, analysant les styles d’interaction des enseignants et de réception des enfants en cours de lecture, mais aussi de ceux de Vygotski (1984, Bruner (1994 ou encore Salazar Orvig et De Weck (2014, nous cherchons à comprendre de quelles manières les adultes racontent des histoires aux enfants et à quelles expériences spécifiques des récits ceux-ci sont confrontés. Dix enfants âgés de 3 à 5 ans ont été filmés au cours de ces séances de lectures d’albums, sans texte et avec texte, avec un de leur parent à leur domicile et avec des pairs et des enseignants à l’école.

  10. Experiments on rheology of non-Newtonian flow of tylose-alginate suspension through a horizontal complex conduit

    International Nuclear Information System (INIS)

    Experiments were conducted on rheological behavior of pseudoplastic non-Newtonian tylose-alginate (solid-liquid) suspensions in isothermal laminar flow in a horizontal conduit with variable geometry. The complex flow of loaded spherical and large-sized particles of 4.4 mm diameter, and dependence of hydrodynamics of organoleptic quality of the loaded fluids governed by Ostwald power law were investigated. The geometry of the horizontal pipe of variable cross-section provided turbulence promoters for fluid flow which generated backflow zones for homogenizing the suspensions by improved mixing quality. The consistency index (K) increased with the volume traction of solid particles, but decreased with temperature; and for a net change in viscosity of 0.75 % tylose concentrated solution, K increased with temperature of the carrier fluid. The structure index, n, varied with the concentration of the hard spheres, but did not vary substantially with temperature. (au)

  11. CFD MODELING OF ITER CABLE-IN-CONDUIT SUPERCONDUCTORS. PART V: COMBINED MOMENTUM AND HEAT TRANSFER IN RIB ROUGHENED PIPES

    International Nuclear Information System (INIS)

    Computational Fluid Dynamics (CFD) techniques have been proposed and applied in a series of papers to analyze cable-in-conduit conductors (CICC) for the International Thermonuclear Experimental Reactor (ITER). Previous work on the pressure drop in the central channel of ITER CICC is extended here to the problem of combined heat and momentum transfer. The CFD model, solved by the FLUENT commercial code, is first validated against 2D and 3D data from compact heat exchangers, showing good agreement. The Colburn analogy between the friction factor f and the Nusselt number Nu is not verified in the considered 2D geometries, as shown by both experiment and simulation. The validated CFD model is finally applied to the 3D analysis of central channel-like geometries relevant for ITER CICC. It is shown that the heat transfer coefficient on the central channel side stays relatively close to the smooth-pipe (Dittus-Boelter) value

  12. Anthropologie des conduites a risque et scarifications a l’adolescence

    OpenAIRE

    David Le Breton

    2014-01-01

    Adolescent risk taking behaviors or scarifications are signs of active resistance against suffering that impregnate their life. They are paradoxical remedies that allows them to get of the distress they felt. Of course, sometimes it is necessary to begin again till circumstances that provoke suffering are always here. They are acts of passage, mean for crossing and conjure the flood of suffering.

  13. Climate change intensification of horizontal water vapor transport in CMIP5

    Science.gov (United States)

    Lavers, David A.; Ralph, F. Martin; Waliser, Duane E.; Gershunov, Alexander; Dettinger, Michael D.

    2015-07-01

    Global warming of the Earth's atmosphere is hypothesized to lead to an intensification of the global water cycle. To determine associated hydrological changes, most previous research has used precipitation. This study, however, investigates projected changes to global atmospheric water vapor transport (integrated vapor transport (IVT)), the key link between water source and sink regions. Using 22 global circulation models from the Climate Model Intercomparison Project Phase 5, we evaluate, globally, the mean, standard deviation, and the 95th percentiles of IVT from the historical simulations (1979-2005) and two emissions scenarios (2073-2099). Considering the more extreme emissions, multimodel mean IVT increases by 30-40% in the North Pacific and North Atlantic storm tracks and in the equatorial Pacific Ocean trade winds. An acceleration of the high-latitude IVT is also shown. Analysis of low-altitude moisture and winds suggests that these changes are mainly due to higher atmospheric water vapor content.

  14. Role of shear stress on nitrite and NOS protein content in different size conduit arteries of swine

    Science.gov (United States)

    Guo, X.; Kassab, G. S.

    2011-01-01

    Aim Inherent fundamental difference exists among arteries of different sizes. The purpose of this study was to evaluate the relation between regional difference of wall shear stress (WSS) in various sizes arteries and contents of nitrite and NO synthase (NOS) isoforms. Methods Five different conduit arteries in a wide range of diameter (1–8 mm) were examined in the hind limbs of 13 pigs. Blood flow rate and outer diameter were measured in vivo to determine WSS. Arterial tissues were harvested for the measurement of nitrite and NOS protein contents. The concentration of nitrite, a product of NO synthesis, was determined by high-performance liquid chromatography method. Western blot analysis was used to assess the protein contents of endothelial NOS (eNOS), inducible NOS (iNOS) and neuronal NOS (nNOS). Results Our data show that WSS increases with a decrease in artery diameter. Nitrite level increases with increasing WSS and hence decreases with artery diameter. The eNOS protein contents decrease with an increase in diameter. No significant difference for iNOS and nNOS protein contents was found with different artery diameter. A significant positive correlation between tissue nitrite and eNOS protein contents was also observed. Finally, the WSS-normalized eNOS is not significantly different in various size vessels. Conclusion Regional difference in blood flow has no effect on iNOS and nNOS protein contents in these conduit arteries. Regional difference in eNOS expression and nitrite contents may be related to the WSS-induced NO by the endothelium under normal physiological conditions. PMID:19432590

  15. Design and synthesis of elastin-like polypeptides for an ideal nerve conduit in peripheral nerve regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Hsueh, Yu-Sheng [Institute of Biomedical Engineering, College of Engineering, National Taiwan University, Taipei 100, Taiwan (China); Institute of Biomedical Engineering, College of Medicine, National Taiwan University, Taipei 100, Taiwan (China); Savitha, S. [Institute of Biomedical Engineering, College of Engineering, National Taiwan University, Taipei 100, Taiwan (China); Department of Biotechnology, Sree Sastha Institute of Engineering and Technology, Chennai (India); Institute of Biomedical Engineering, College of Medicine, National Taiwan University, Taipei 100, Taiwan (China); Sadhasivam, S. [Division of Biomedical Engineering and Nanomedicine Research, National Health Research Institutes, Miaoli 350, Taiwan (China); Lin, Feng-Huei, E-mail: double@ntu.edu.tw [Institute of Biomedical Engineering, College of Engineering, National Taiwan University, Taipei 100, Taiwan (China); Division of Biomedical Engineering and Nanomedicine Research, National Health Research Institutes, Miaoli 350, Taiwan (China); Institute of Biomedical Engineering, College of Medicine, National Taiwan University, Taipei 100, Taiwan (China); Shieh, Ming-Jium [Institute of Biomedical Engineering, College of Engineering, National Taiwan University, Taipei 100, Taiwan (China); College of Medicine, National Taiwan University Hospital, Taipei 100, Taiwan (China); Institute of Biomedical Engineering, College of Medicine, National Taiwan University, Taipei 100, Taiwan (China)

    2014-05-01

    The study involves design and synthesis of three different elastin like polypeptide (ELP) gene monomers namely ELP1, ELP2 and ELP3 that encode for ELP proteins. The formed ELPs were assessed as an ideal nerve conduit for peripheral nerve regeneration. ELP1 was constructed with a small elongated pentapeptide carrying VPGVG sequence to mimic the natural polypeptide ELP. The ELP2 was designed by the incorporation of 4-penta peptide chains to improve the biocompatibility and mechanical strength. Thus, the third position in unique VPGVG was replaced with alanine to VPAVG and in a similar way modified to VPGKG, VPGEG and VPGIG with the substitution of lysine, glutamic acid and isoleucine. In ELP3, fibronectin C5 domain endowed with REDV sequence was introduced to improve the cell attachment. The ELP1, ELP2 and ELP3 proteins expressed by Escherichia coli were purified by inverse transition cycling (ITC). The purified ELPs were confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and western blotting. The Schwann cell (SC) morphology and cell adhesion were assessed by fabrication of ELP membrane cross-linked with glutaraledhyde. The Schwann cell proliferation was measured by WST-1 assay. Immunofluorostaining of Schwann cells was accomplished with SC specific phenotypic marker, S100. - Highlights: • Design and synthesis of three gene monomers of elastin like polypeptides (ELP1, 2 and 3) were reported. • Molecular weight of ITC purified ELP1, ELP2 and ELP3 was in the range of 37–38 kDa. • Schwann cell adhesion was found to be prominent in ELP3 and could be used as nerve conduit for peripheral nerve regeneration.

  16. Correction technique for raman water vapor lidar signal dependent bias and suitability for water vapor trend monitoring in the upper troposphere

    Directory of Open Access Journals (Sweden)

    D. N. Whiteman

    2011-12-01

    Full Text Available The MOHAVE-2009 campaign brought together diverse instrumentation for measuring atmospheric water vapor. We report on the participation of the ALVICE mobile laboratory in the MOHAVE-2009 campaign. In an appendix we also report on the performance of the corrected Vaisala RS92 radiosonde during the campaign. A new radiosonde based calibration algorithm is presented that reduces the influence of atmospheric variability on the derived calibration constant. The MOHAVE-2009 campaign permitted all Raman lidar systems participating to discover and address measurement biases in the upper troposphere and lower stratosphere. The ALVICE lidar system was found to possess a wet bias which was attributed to fluorescence of insect material that was deposited on the telescope early in the mission. A correction technique is derived and applied to the ALVICE lidar water vapor profiles. Other sources of wet biases are discussed and data from other Raman lidar systems are investigated revealing that wet biases in upper tropospheric and lower stratospheric water vapor measurements appear to be quite common in Raman lidar systems. Lower stratospheric climatology of water vapor is investigated both as a means to check for the existence of these wet biases in Raman lidar data and as a source of correction for the data. The correction is offered as a general method to both quality control Raman water vapor lidar data and to correct those data that have signal-dependent bias. The influence of the correction is shown to be small at regions in the upper troposphere where recent work indicates detection of trends in atmospheric water vapor may be most resistant to additional noise sources. The correction shown here holds promise for permitting useful upper tropospheric water vapor profiles to be consistently measured by Raman lidar within NDACC and elsewhere despite the prevalence of instrumental and atmospheric effects that can contaminate the very low signal to noise measurements in the UT.

  17. Surface tension, coexistence curve, and vapor pressure of binary liquid-gas mixtures

    Science.gov (United States)

    Do, V. T.; Straub, J.

    1986-01-01

    The objective of this paper is to present measurements of the vapor pressure, capillary coefficient, and refractive index of four binary mixtures, CO2-SF6, R14-SF6, SF6-R13B1, and SF6-R22, at liquid-vapor equilibrium at different average concentrations. The measuring temperature range covered the entire liquid-vapor region from the triple line up to the critical point. The capillary coefficient was determined by means of the capillary rise method; the refractive index, by measuring the angle of refraction of a light beam passing through a prism and the sample. In order to obtain the liquid-vapor densities of pure substances the Lorentz-Lorenz relation can be used. However, in applying this relation to calculate the liquid-vapor densities of a mixture, one may need the concentrations of both the liquid and the vapor phase, which are, for the most part, quite different from the average concentration of the mixture. Calculating the concentrations of both fluid phases with the aid of an equation of state and comparing with measurements, we could show that the molar refraction coefficient of the mixtures can be simply determined from the average concentration and the molar refraction coefficients of their pure components. The surface tension of the mixtures could then be calculated from the measured capillary coefficient and the refractive index with the aid of the Lorentz-Lorenz relation.

  18. Static Water Vapor Feed Electrolyzer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of a static vapor feed electrolyzer utilizing an advanced bipolar plate that produces sub-saturated H2 and O2 is proposed. This novel bipolar design can...

  19. Vapor Cavitation in Dynamically Loaded Journal Bearings

    Science.gov (United States)

    Jacobson, B. O.; Hamrock, B. J.

    1983-01-01

    High speed motion camera experiments were performed on dynamically loaded journal bearings. The length to diameter ratio of the bearing, the speed of the roller and the tube, the surface material of the roller, and the static and dynamic eccentricity of the bearing were varied. One hundred and thirty-four cases were filmed. The occurrence of vapor cavitation was clearly evident in the films and figures presented. Vapor cavitation was found to occur when the tensile stress applied to the oil exceeded the tensile strength of the oil or the binding of the oil to the surface. The physical situation in which vapor cavitation occurs is during the squeezing and sliding motion within a bearing. Besides being able to accurately capture the vapor cavitation on film, an analysis of the formation and collapse of the cavitation bubbles and characteristics of the bubble content are presented.

  20. Vaporization of Samarium trichloride studied by thermogravimetry

    International Nuclear Information System (INIS)

    In the present work, the vaporization reaction of SmCl3(l) obtained from the 'in situ' reaction of Sm2O3(s) and Cl2(g)-C(s) was studied by thermogravimetry under controlled atmosphere. The effects of both the temperature between 825 C degrees and 950 C degrees and the total flow gas on the vaporization rate of the following reaction: SmCl3(l) = SmCl3(g) were analyzed. The vaporization rate of the process was found to be independent of then total gas flow rate and highly dependent on the temperature. Eap calculation led to a value of 240 ± 10 kJ.mol-1. A comparison between this value and that of the molar enthalpy of vaporization allow to the conclusion that the reaction occur in conditions near to equilibrium. The SmCl3 identity was determined by X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). (author)

  1. Solid-state barium-vapor detector

    International Nuclear Information System (INIS)

    The need for electrical switching devices for use in high-temperature radioactive environments in space nuclear power systems has led to the development of the cesium-barium tacitron. Effective evaluation of electrically insulating joints for the barium-cesium tacitron requires a method for the in situ detection of barium vapor which may leak through the joint. A solid-state barium-vapor detector has been developed using a barium fluoride solid electrolyte. The sensor produced an output voltage of greater than 1 V in response to a barium partial pressure of less than 0.1 Pa. The selectivity of the sensor to barium vapor, rather than to the reduced oxygen partial pressure resulting from the presence of an active alkaline-earth metal vapor, was confirmed

  2. Rubidium "whiskers" in a vapor cell

    OpenAIRE

    Balabas, M. V.; Sushkov, A. O.; Budker, D.

    2006-01-01

    Crystals of metallic rubidium are observed ``growing'' from paraffin coating of buffer-gas-free glass vapor cells. The crystals have uniform square cross-section, $\\approx 30 \\mu$m on the side, and reach several mm in length.

  3. GOES WATER VAPOR TRANSPORT V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GOES Water Vapor Transport CD contains nineteen months of geostationary satellite-derived products spanning the 1987/1988 El Nino Southern Oscillation (ENSO)...

  4. Rubidium "whiskers" in a vapor cell

    CERN Document Server

    Balabas, M V; Sushkov, A O

    2006-01-01

    Crystals of metallic rubidium are observed ``growing'' from paraffin coating of buffer-gas-free glass vapor cells. The crystals have uniform square cross-section, $\\approx 35 \\mu$m on the side, and reach several mm in length.

  5. Perfluorocarbon vapor tagging of blasting cap detonators

    International Nuclear Information System (INIS)

    A plug for a blasting cap is made of an elastomer in which is dissolved a perfluorocarbon. The perfluorocarbon is released as a vapor into the ambient over a long period of time to serve as a detectable taggant

  6. Perfluorocarbon vapor tagging of blasting cap detonators

    Science.gov (United States)

    Dietz, Russell N. (Shoreham, NY); Senum, Gunnar I. (Patchogue, NY)

    1981-01-01

    A plug for a blasting cap is made of an elastomer in which is dissolved a perfluorocarbon. The perfluorocarbon is released as a vapor into the ambient over a long period of time to serve as a detectable taggant.

  7. Innovation driven by meaning

    OpenAIRE

    Öberg, Åsa

    2012-01-01

    Hi-tech companies that want to innovate their products use, quite often, and quite naturally, technology as a driver. But, technology is only one of several drivers of change within product development. It is becoming more and more accessible and alone, cannot serve as the only mean to stay competitive.  This research sheds light on a different driver of innovation – namely, through the perspective of “meaning”. An innovation, driven by the search for a new meaning of a product, is connected ...

  8. Information and Meaning

    OpenAIRE

    Christophe Menant

    2003-01-01

    Abstract: We propose here to clarify some of the relations existing between information and meaning by showing how meaningful information can be generated by a system submitted to a constraint. We build up definitions and properties for meaningful information, a meaning generator system and the domain of efficiency of a meaning (to cover cases of meaningful information transmission). Basic notions of information processing are used.

  9. Storage of light in atomic vapor

    OpenAIRE

    Phillips, D. F.; Fleischhauer, A.; Mair, A.; R.L. Walsworth; M. D. Lukin

    2000-01-01

    We report an experiment in which a light pulse is decelerated and trapped in a vapor of Rb atoms, stored for a controlled period of time, and then released on demand. We accomplish this storage of light by dynamically reducing the group velocity of the light pulse to zero, so that the coherent excitation of the light is reversibly mapped into a collective Zeeman (spin) coherence of the Rb vapor.

  10. Metal Vapor Arcing Risk Assessment Tool

    Science.gov (United States)

    Hill, Monika C.; Leidecker, Henning W.

    2010-01-01

    The Tin Whisker Metal Vapor Arcing Risk Assessment Tool has been designed to evaluate the risk of metal vapor arcing and to help facilitate a decision toward a researched risk disposition. Users can evaluate a system without having to open up the hardware. This process allows for investigating components at risk rather than spending time and money analyzing every component. The tool points to a risk level and provides direction for appropriate action and documentation.

  11. D2O-vapor table

    International Nuclear Information System (INIS)

    The first chapters describe vapor pressure curve, critical data and heat of evaporation of D2O. A chapter about specific enthalpy and entropy of D2O follows. Further chapters deal with thermal conductivity and viscosity of liquid and vaporous D2O, surface tension and the comparison of values of H2O and D2O. The appendix lists state date over 198 pages. (SPI)

  12. Water vapor distribution in protoplanetary disks

    OpenAIRE

    Du, Fujun; Bergin, Edwin A.

    2014-01-01

    Water vapor has been detected in protoplanetary disks. In this work we model the distribution of water vapor in protoplanetary disks with a thermo-chemical code. For a set of parameterized disk models, we calculate the distribution of dust temperature and radiation field of the disk with a Monte Carlo method, and then solve the gas temperature distribution and chemical composition. The radiative transfer includes detailed treatment of scattering by atomic hydrogen and absorp...

  13. Saturn's Stratospheric Water Vapor Distribution

    Science.gov (United States)

    Hesman, Brigette E.; Bjoraker, Gordon L.; Achterberg, Richard K.; Romani, Paul N.; Irwin, Patrick G. J.

    2015-11-01

    Water is a sought after commodity in the solar system. It is used as an indication of life, planetary formation timescales, and signatures of past cometary impacts. In Saturn’s atmosphere there are two sources of water: an internal primordial reservoir that is confined to the troposphere, and an external source of unknown origin that delivers water to the stratosphere. Potential sources of stratospheric water include: Saturn’s main rings (via neutral infall and/or ions transported along magnetic field lines – “Ring Rain”), interplanetary dust particles, and the E-ring that is supplied with water from the plumes of Enceladus. Measuring the latitudinal and seasonal variation of H2O on Saturn will constrain the source of Saturn’s stratospheric water.Cassini’s Composite InfraRed Spectrometer (CIRS) has detected emission lines of H2O on Saturn at wavelengths of 40 and 50 microns. CIRS also retrieves the temperature of the stratosphere using CH4 lines at 7.7 microns. Using our retrieved temperatures, we derive the mole fraction of H2O at the 0.5-5 mbar level for comparison with water-source models. The latitudinal variation of stratospheric water vapor will be presented as a first step in understanding the external source of water on Saturn. The observed local maximum near Saturn’s equator supports either a neutral infall from the rings or a source in the E-ring. We will look for secondary maxima at mid-latitudes to determine whether “Ring Rain” also contributes to the inventory of water in Saturn’s upper atmosphere.

  14. Dynamics within geyser conduits, and sensitivity to environmental perturbations: insights from a periodic geyser in the El Tatio Geyser Field, Atacama Desert, Chile

    Science.gov (United States)

    Munoz-Saez, Carolina; Manga, Michael; Hurwitz, Shaul; Rudolph, Maxwell L.; Namiki, Atsuko; Wang, Chi-Yuen

    2015-01-01

    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 conduit 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 conduit after an eruption, driven by the pressure difference between water in the conduit 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 conduit and reservoir. Further evidence favoring the dominance of internal processes in controlling periodicity is also provided by the absence of responses of the geyser to environmental perturbations (air pressure, temperature and probably also Earth tides).

  15. Peripheral nerve reconstruction with epsilon-caprolactone conduits seeded with vasoactive intestinal peptide gene-transfected mesenchymal stem cells in a rat model

    Science.gov (United States)

    Hernández-Cortés, P.; Toledo-Romero, M. A.; Delgado, M.; Sánchez-González, C. E.; Martin, F.; Galindo-Moreno, P.; O'Valle, F.

    2014-08-01

    Objective. Attempts have been made to improve nerve conduits 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 conduits. Approach. The sciatic nerve of each male Wistar rat was transected unilaterally at 10 mm and then repaired with Dl-lactic-?-caprolactone conduits. 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 controls. 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-?-caprolactone conduits and that this method represents a potential useful clinical approach to repairing peripheral nerve damage.

  16. Functional Regeneration of Recurrent Laryngeal Nerve Injury During Thyroid Surgery Using an Asymmetrically Porous Nerve Guide Conduit in an Animal Model

    OpenAIRE

    Choi, Jeong-Seok; Oh, Se Heang; An, Hye-Young; Kim, Young-Mo; Lee, Jin Ho; Lim, Jae-Yol

    2014-01-01

    Background: Vocal cord paralysis (VCP) caused by recurrent laryngeal nerve (RLN) damage during thyroidectomy commonly results in serious medico-legal problems. The purpose of this study was to evaluate the usefulness of an asymmetrically porous polycaprolactone (PCL)/Pluronic F127 nerve guide conduit (NGC) for functional regeneration in a RLN injury animal model.

  17. Aerodynamic improvement of the assembly through which gas conduits are taken into a smoke stack by simulating gas flow on a computer

    Science.gov (United States)

    Prokhorov, V. B.; Fomenko, M. V.; Grigor'ev, I. V.

    2012-06-01

    Results from computer simulation of gas flow motion for gas conduits taken on one and two sides into the gas-removal shaft of a smoke stack with a constant cross section carried out using the SolidWorks and FlowVision application software packages are presented.

  18. Scalable K-Means++

    OpenAIRE

    Bahmani, Bahman; Moseley, Benjamin; Vattani, Andrea; Kumar, Ravi; Vassilvitskii, Sergei

    2012-01-01

    Over half a century old and showing no signs of aging, k-means remains one of the most popular data processing algorithms. As is well-known, a proper initialization of k-means is crucial for obtaining a good final solution. The recently proposed k-means++ initialization algorithm achieves this, obtaining an initial set of centers that is provably close to the optimum solution. A major downside of the k-means++ is its inherent sequential nature, which limits its applicability...

  19. Vapor pressures and enthalpies of vaporization of a series of ? and ?-lactones by correlation gas chromatography

    International Nuclear Information System (INIS)

    Highlights: • The vaporization enthalpies of ?-octanolactone, ?- and ?-undecanolactone and ? and ?-dodecanolactone are reported. • Equations for predicting the vapor pressures over the temperature range T = (298.15 to 350) K are provided. • Vaporization enthalpies are compared to predicted values. - Abstract: The vaporization enthalpies of ?-octanolactone, ?- and ?-undecanolactone and ? and ?-dodecanolactone used commercially as flavor ingredients are reported as are their vapor pressures over the temperature range T = (298.15 to 350) K. Vaporization enthalpies at T = 298.15 K of: (66.0 ± 3.9), (79.4 ± 4.4), (80.1 ± 4.5), (83.9 ± 4.6), and (84.61 ± 4.7) kJ · mol?1 and vapor pressures also at T = 298.15 K of: (2.8 ± 0.9), (0.12 ± 0.05), (0.09 ± 0.04), (0.04 ± 0.02), and (0.03 ± 0.02) Pa, respectively, have been evaluated by correlation gas chromatography experiments. The vaporization enthalpies of the lactones studied are reproduced within ±0.5 kJ · mol?1 using a group additivity scheme reported previously for ?- and ?-lactones. The vaporization enthalpies of the ?- and ?-lactones are compared to a similar series of ?-lactones

  20. Uranium dioxide vapor condensation by rarefaction waves in the ORNL Capacitor Discharge Vaporization tests

    International Nuclear Information System (INIS)

    A spherical shock tube type model with homogeneous nucleation and particle condensation growth in the rarefaction wave fan has been developed and applied to the Capacitor Discharge Vaporization (CDV) experiments conducted at ORNL. In each CDV test, a stack of molten UO2 fuel pellets contained in a quartz tube were partially vaporized in an argon environment by rapid energy deposition through capacitor discharge. A UO2 aerosol was generated during the resulting expansion of the UO2 vapor. The position of the expanding UO2 vapor-argon interface as a function of time was estimated from movies of the CDV tests

  1. Holographic studies of the vapor explosion of vaporizing water-in-fuel emulsion droplets

    Science.gov (United States)

    Sheffield, S. A.; Hess, C. F.; Trolinger, J. D.

    1982-01-01

    Holographic studies were performed which examined the fragmentation process during vapor explosion of a water-in-fuel (hexadecane/water) emulsion droplet. Holograms were taken at 700 to 1000 microseconds after the vapor explosion. Photographs of the reconstructed holograms reveal a wide range of fragment droplet sizes created during the explosion process. Fragment droplet diameters range from below 10 microns to over 100 microns. It is estimated that between ten thousand and a million fragment droplets can result from this extremely violent vapor explosion process. This enhanced atomization is thus expected to have a pronounced effect on vaporization processes which are present during combustion of emulsified fuels.

  2. Modeling of Vapor-Liquid-Solid Equilibria in Acidic Aqueous Solutions

    DEFF Research Database (Denmark)

    Christensen, Søren Gregers; Thomsen, Kaj

    2003-01-01

    The phase behavior (vapor - liquid equilibria (VLE) and solid - liquid equilibria (SLE)) and thermal properties of aqueous solutions of ions like (K+, Na+, NH4+, Ca2+, Cl-) in the presence of phosphoric acid (H3PO4, H2PO4-, HPO42- ) and nitric acid (HNO3, NO3-) are described by means of the...

  3. Agency, Context and Meaning

    DEFF Research Database (Denmark)

    Folkmann, Mads Nygaard

    The paper is a meta-discursive contribution to the discussion of how design can be understood as a medium of meaning formation and questioning of meaning. Further, the paper builds on plea for the role of humanities in relation to formulate relevant questions in design through conceptualizing the...

  4. The Meaning of Audiolingual.

    Science.gov (United States)

    Brooks, Nelson

    This paper constitutes an analysis of the audiolingual concept in terms of what it was originally intended to mean and what it has come to mean in second language teaching. Basic to the concept is the notion that language was originally a matter of oral communication, and that although writing and writing systems are central, they have secondary…

  5. Sexual Function after Non-Nerve-Sparing Radical Cystoprostatectomy: A Comparison between Ileal Conduit Urinary Diversion and Orthotopic Ileal Neobladder Substitution

    Directory of Open Access Journals (Sweden)

    M.A Asgari

    2013-07-01

    Full Text Available Objective To compare the erectile function (EF and sexual desire (SD in men after radical cystoprostatectomy (RCP who had either an ileal conduit urinary diversion or orthotropic ileal neobladder substitution. Materials and Methods Eighty one sexually active men with bladder cancer were enrolled in this prospective study. After RCP according to patients' preferences they underwent either ileal conduit urinary diversion (n = 41 or orthotropic ileal neobladder substitution (n = 40. EF and SD were assessed using International Index of Erectile Function (IIEF questionnaire. Patients were assessed at 4-week before surgery and were followed up at 1, 6, and 12-month postoperatively using the same questionnaire. Results Postoperatively the EF and SD domains deteriorated significantly in both groups, but in a small proportion of the patients submitted to ileal neobladder they gradually improved with time (P = 0.006. At 12-month postoperative period, 4 (9.8% and 14 (35.0% patients in ileal conduit and ileal neobladder groups were able to achieve erections hard enough for vaginal penetration and maintained their erection to completion of intercourse, respectively (P = 0.006. Among patients in the ileal conduit and ileal neobladder groups, additional 4 (9.8% and 7 (17.1% patients were able to get some erection, but were unable to maintain their erection to completion of intercourse (P = 0.02. At 12-month follow up period 24.4% of the ileal conduit and 45.0% of the ileal neobladder patients rated their sexual desire very high or high (P = 0.01. Conclusion When performed properly, orthotopic ileal neobladder substitution after RCP offers better long-term results in terms of EF and SD.

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

    Science.gov (United States)

    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 evaluated as well in this study.

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

    Science.gov (United States)

    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 evaluated as well in this study. PMID:26387032

  8. Sexual Function after Non-Nerve-Sparing Radical Cystoprostatectomy: A Comparison between Ileal Conduit Urinary Diversion and Orthotopic Ileal Neobladder Substitution

    Scientific Electronic Library Online (English)

    M.A, Asgari; M.R, Safarinejad; N, Shakhssalim; M, Soleimani; A, Shahabi; E, Amini.

    2013-07-01

    Full Text Available Objective To compare the erectile function (EF) and sexual desire (SD) in men after radical cystoprostatectomy (RCP) who had either an ileal conduit urinary diversion or orthotropic ileal neobladder substitution. Materials and Methods Eighty one sexually active men with bladder cancer were enroll [...] ed in this prospective study. After RCP according to patients' preferences they underwent either ileal conduit urinary diversion (n = 41) or orthotropic ileal neobladder substitution (n = 40). EF and SD were assessed using International Index of Erectile Function (IIEF) questionnaire. Patients were assessed at 4-week before surgery and were followed up at 1, 6, and 12-month postoperatively using the same questionnaire. Results Postoperatively the EF and SD domains deteriorated significantly in both groups, but in a small proportion of the patients submitted to ileal neobladder they gradually improved with time (P = 0.006). At 12-month postoperative period, 4 (9.8%) and 14 (35.0%) patients in ileal conduit and ileal neobladder groups were able to achieve erections hard enough for vaginal penetration and maintained their erection to completion of intercourse, respectively (P = 0.006). Among patients in the ileal conduit and ileal neobladder groups, additional 4 (9.8%) and 7 (17.1%) patients were able to get some erection, but were unable to maintain their erection to completion of intercourse (P = 0.02). At 12-month follow up period 24.4% of the ileal conduit and 45.0% of the ileal neobladder patients rated their sexual desire very high or high (P = 0.01). Conclusion When performed properly, orthotopic ileal neobladder substitution after RCP offers better long-term results in terms of EF and SD.

  9. How closely do changes in surface and column water vapor follow Clausius-Clapeyron scaling in climate change simulations?

    International Nuclear Information System (INIS)

    The factors governing the rate of change in the amount of atmospheric water vapor are analyzed in simulations of climate change. The global-mean amount of water vapor is estimated to increase at a differential rate of 7.3% K-1 with respect to global-mean surface air temperature in the multi-model mean. Larger rates of change result if the fractional change is evaluated over a finite change in temperature (e.g., 8.2% K-1 for a 3 K warming), and rates of change of zonal-mean column water vapor range from 6 to 12% K-1 depending on latitude. Clausius-Clapeyron scaling is directly evaluated using an invariant distribution of monthly-mean relative humidity, giving a rate of 7.4% K-1 for global-mean water vapor. There are deviations from Clausius-Clapeyron scaling of zonal-mean column water vapor in the tropics and mid-latitudes, but they largely cancel in the global mean. A purely thermodynamic scaling based on a saturated troposphere gives a higher global rate of 7.9% K-1. Surface specific humidity increases at a rate of 5.7% K-1, considerably lower than the rate for global-mean water vapor. Surface specific humidity closely follows Clausius-Clapeyron scaling over ocean. But there are widespread decreases in surface relative humidity over land (by more than 1% K-1 in many regions), and it is argued that decreases of this magnitude could result from the land/ocean contrast in surface warming.

  10. Meaning in Work Life

    DEFF Research Database (Denmark)

    Ravn, Ib

        An important aspect of modern work is the meaning that people find in it. Research on this topic has typically asked respondents to name the elements of their work they see as meaningful (e.g., Meaning of Working International Research Team, 1987).     However, a theory of what makes work...... meaningful is still lacking (Harpaz & Fu, 2002), as are definitions of key terms. Here, I define meaning as the experience that something fits into a wider context or coheres within a larger whole.     I conceptualize meaning in work life as deriving from four factors, each of which helps us contribute to...... something larger than ourselves (Seligman, 2002) through our work. Thus, a person experiences meaning in work life when she... A. is able to use her signature strengths at work (Peterson and Seligman, 2004), B. makes an important contribution to the workplace (Drucker, 1999), C. participates in a productive...

  11. Detection of hydrogen peroxide vapor by use of manganese(IV) oxide as catalyst for calorimetric gas sensors

    OpenAIRE

    Oberländer, Jan; Kirchner, Patrick; Boyen, Hans-Gerd; Schöning, Michael J.

    2014-01-01

    In this work, the catalyst manganese(IV) oxide (MnO2), of calorimetric gas sensors (to monitor the sterilization agent vaporized hydrogen peroxide) has been investigated in more detail. Chemical analyses by means of X-ray-induced photoelectron spectroscopy have been performed to unravel the surface chemistry prior and after exposure to hydrogen peroxide vapor at elevated temperature, as applied in the sterilization processes of beverage cartons. The surface characterization reveals a change i...

  12. Utilization of the second gradient theory in continuum mechanics to study motions and thermodynamics of liquid-vapor interfaces

    OpenAIRE

    Gouin, Henri

    1987-01-01

    A thermomechanical model of continuous fluid media based on second gradient theory is used to study motions in liquid-vapor interfaces. At equilibrium, the model is shown to be equivalent to mean-field molecular theories of capillarity. In such fluids, conservative motions verify first integrals that lead to Kelvin circulation theorems and potential equations. The dynamical surface tension of liquid-vapor interfaces is deduced from viscous fluid equations. The result provide...

  13. Precipitation and circulation response to warming shaped by radiative changes of clouds and water vapor

    Science.gov (United States)

    Voigt, Aiko; Shaw, Tiffany

    2015-04-01

    The atmospheric circulation controls how global warming will be expressed regionally, in particular by locally altering the hydrological cycle through changes in moisture transport. While climate models robustly project an increase of global-mean precipitation at a rate of 1-3% per degree warming, there is much less consensus on how the global-mean increase will be distributed regionally, and confidence in long-term projections of regional precipitation changes remains much lower than for temperature. Here, two CMIP5 aquaplanet models, MPI-ESM and IPSL-CM5A, and their response to a uniform 4K increase of sea-surface temperatures are compared to study how radiative changes of clouds and water vapor influence the regional response of precipitation and the circulation to global warming, and to investigate to which extent uncertainty in clouds and water vapor lead to uncertainty in the precipitation and circulation response. Using the cloud and water-vapor locking method it is shown that cloud-radiative changes dominate the response of deep-tropical precipitation and the strength of the Hadley circulation, and lead to disagreement between the two models. In MPI-ESM changes in tropical ice clouds cause a narrowing of the inter-tropical convergence zone (ITCZ) and a strengthening of the Hadley circulation, whereas they lead to a widening of the ITCZ and a weakening of the Hadley circulation in IPSL-CM5A. Radiative changes of clouds and water vapor also impact the subtropics and extratropics. Cloud changes are found to amplify the poleward expansion of the tropical belt and the poleward shift of the extratropical jet, consistent with the fact that they stabilize the tropical atmosphere. In contrast, water vapor changes destabilize the tropical atmosphere and contract the tropical belt and jet towards the equator. Both models show the opposing impacts of cloud and water vapor changes on the jet shift, but the degree of compensation between cloud and water-vapor changes is model-dependent. These results demonstrate that radiative changes of clouds and water vapor are not only integral to the magnitude of future global-mean temperature but also to regional climate change. A deeper understanding of the radiative coupling between clouds, water vapor and the circulation and how this coupling might respond to climate change is thus needed to understand and predict changes in the hydrological cycle.

  14. Modeling of the vapor cycle of Laguna Verde with the PEPSE code to conditions of thermal power licensed at present (2027 MWt)

    International Nuclear Information System (INIS)

    By means of the use of the performance evaluation of power system efficiencies (PEPSE) code was modeled the vapor cycle of the nuclear power station of Laguna Verde to reproduce the nuclear plant behavior to conditions of thermal power, licensed at present (2027 MWt); with the purpose of having a base line before the implementation of the project of extended power increase. The model of the gauged vapor cycle to reproduce the nuclear plant conditions makes use of the PEPSE model, design case of the vapor cycle of nuclear power station of Laguna Verde, which has as main components of the model the great equipment of the vapor cycle of Laguna Verde. The design case model makes use of information about the design requirements of each equipment for theoretically calculating the electric power of exit, besides thermodynamic conditions of the vapor cycle in different points. Starting from the design model and making use of data of the vapor cycle measured in the nuclear plant; the adjustment factors were calculated for the different equipment s of the vapor cycle, to reproduce with the PEPSE model the real vapor cycle of Laguna Verde. Once characterized the model of the vapor cycle of Laguna Verde, we can realize different sensibility studies to determine the effects macros to the vapor cycle by the variation of certain key parameters. (Author)

  15. Scalable K-Means++

    CERN Document Server

    Bahmani, Bahman; Vattani, Andrea; Kumar, Ravi; Vassilvitskii, Sergei

    2012-01-01

    Over half a century old and showing no signs of aging, k-means remains one of the most popular data processing algorithms. As is well-known, a proper initialization of k-means is crucial for obtaining a good final solution. The recently proposed k-means++ initialization algorithm achieves this, obtaining an initial set of centers that is provably close to the optimum solution. A major downside of the k-means++ is its inherent sequential nature, which limits its applicability to massive data: one must make k passes over the data to find a good initial set of centers. In this work we show how to drastically reduce the number of passes needed to obtain, in parallel, a good initialization. This is unlike prevailing efforts on parallelizing k-means that have mostly focused on the post-initialization phases of k-means. We prove that our proposed initialization algorithm k-means|| obtains a nearly optimal solution after a logarithmic number of passes, and then show that in practice a constant number of passes suffic...

  16. Soils - Mean Permeability

    Data.gov (United States)

    Kansas Data Access and Support Center — This digital spatial data set provides information on the magnitude and spatial pattern of depth-weighted, mean soil permeability throughout the State of Kansas....

  17. Intentional Meaning of Programs

    OpenAIRE

    Ratiu, Daniel Petrica

    2009-01-01

    In this dissertation we present a new approach for bridging the gap between the domain knowledge and programs by defining explicit mappings between program entities and domain concepts shared within domain ontologies. We call these mappings the ``intentional interpretation'' and they define explicitly the ``intentional meaning'' of a program. We use the intentional meaning to characterize the degree in which the code reflects the domain knowledge. We investigate how do the mismatches be...

  18. Stats means business

    CERN Document Server

    Buglear, John

    2010-01-01

    Stats Means Business is an introductory textbook written for Business, Hospitality and Tourism students who take modules on Statistics or Quantitative research methods. Recognising that most users of this book will have limited if any grounding in the subject, this book minimises technical language, provides clear definition of key terms, and gives emphasis to interpretation rather than technique.Stats Means Business enables readers to:appreciate the importance of statistical analysis in business, hospitality and tourism understand statis

  19. Effects of thermal vapor diffusion on seasonal dynamics of water in the unsaturated zone

    Science.gov (United States)

    Milly, P.C.D.

    1996-01-01

    The response of water in the unsaturated zone to seasonal changes of temperature (T) is determined analytically using the theory of nonisothermal water transport in porous media, and the solutions are tested against field observations of moisture potential and bomb fallout isotopic (36Cl and3H) concentrations. Seasonally varying land surface temperatures and the resulting subsurface temperature gradients induce thermal vapor diffusion. The annual mean vertical temperature gradient is close to zero: however, the annual mean thermal vapor flux is downward, because the temperature-dependent vapor diffusion coefficient is larger, on average, during downward diffusion (occurring at high T) than during upward diffusion (low T). The annual mean thermal vapor flux is shown to decay exponentially with depth; the depth (about 1 m) at which it decays to ??-1 of its surface value is one half of the corresponding decay depth for the amplitude of seasonal temperature changes. This depth-dependent annual mean flux is effectively a source of water, which must be balanced by a flux divergence associated with other transport processes. In a relatively humid environment the liquid fluxes greatly exceed the thermal vapor fluxes, so such a balance is readily achieved without measurable effect on the dynamics of water in the unsaturated zone. However, if the mean vertical water flux through the unsaturated zone is very small (thermal vapor flux must be balanced mostly by a matric-potential-induced upward flux of water. This return flux may include both vapor and liquid components. Below any near-surface zone of weather- related fluctuations of matric potential, maintenance of this upward flux requires an increase with depth in the annual mean matric potential; this theoretical prediction is supported by long-term field measurements in the Chihuahuan Desert. The analysis also makes predictions, confirmed by the field observations, regarding the seasonal variations of matric potential at a given depth. The conceptual model of unsaturated zone water transport developed here implies the possibility of near-surface trapping of any aqueous constituent introduced at the surface.

  20. Vapor scavenging by atmospheric aerosol particles

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, E.

    1996-05-01

    Particle growth due to vapor scavenging was studied using both experimental and computational techniques. Vapor scavenging by particles is an important physical process in the atmosphere because it can result in changes to particle properties (e.g., size, shape, composition, and activity) and, thus, influence atmospheric phenomena in which particles play a role, such as cloud formation and long range transport. The influence of organic vapor on the evolution of a particle mass size distribution was investigated using a modified version of MAEROS (a multicomponent aerosol dynamics code). The modeling study attempted to identify the sources of organic aerosol observed by Novakov and Penner (1993) in a field study in Puerto Rico. Experimentally, vapor scavenging and particle growth were investigated using two techniques. The influence of the presence of organic vapor on the particle`s hydroscopicity was investigated using an electrodynamic balance. The charge on a particle was investigated theoretically and experimentally. A prototype apparatus--the refractive index thermal diffusion chamber (RITDC)--was developed to study multiple particles in the same environment at the same time.

  1. Thermodynamics and Kinetics of Silicate Vaporization

    Science.gov (United States)

    Jacobson, Nathan S.; Costa, Gustavo C. C.

    2015-01-01

    Silicates are a common class of materials that are often exposed to high temperatures. The behavior of these materials needs to be understood for applications as high temperature coatings in material science as well as the constituents of lava for geological considerations. The vaporization behavior of these materials is an important aspect of their high temperature behavior and it also provides fundamental thermodynamic data. The application of Knudsen effusion mass spectrometry (KEMS) to silicates is discussed. There are several special considerations for silicates. The first is selection of an appropriate cell material, which is either nearly inert or has well-understood interactions with the silicate. The second consideration is proper measurement of the low vapor pressures. This can be circumvented by using a reducing agent to boost the vapor pressure without changing the solid composition or by working at very high temperatures. The third consideration deals with kinetic barriers to vaporization. The measurement of these barriers, as encompassed in a vaporization coefficient, is discussed. Current measured data of rare earth silicates for high temperature coating applications are discussed. In addition, data on magnesium-iron-silicates (olivine) are presented and discussed.

  2. A review of vapor intrusion models.

    Science.gov (United States)

    Yao, Yijun; Shen, Rui; Pennell, Kelly G; Suuberg, Eric M

    2013-03-19

    A complete vapor intrusion (VI) model, describing vapor entry of volatile organic chemicals (VOCs) into buildings located on contaminated sites, generally consists of two main parts: one part describing vapor transport in the soil and the other describing its entry into the building. Modeling the soil vapor transport part involves either analytically or numerically solving the equations of vapor advection and diffusion in the subsurface. Contaminant biodegradation must often also be included in this simulation, and can increase the difficulty of obtaining a solution, especially when explicitly considering coupled oxygen transport and consumption. The models of contaminant building entry pathway are often coupled to calculations of indoor air contaminant concentration, and both are influenced by building construction and operational features. The description of entry pathway involves consideration of building foundation characteristics, while calculation of indoor air contaminant levels requires characterization of building enclosed space and air exchange within this. This review summarizes existing VI models, and discusses the limits of current screening tools commonly used in this field. PMID:23360069

  3. DISTRIBUTION OF WATER VAPOR IN MOLECULAR CLOUDS

    International Nuclear Information System (INIS)

    We report the results of a large-area study of water vapor along the Orion Molecular Cloud ridge, the purpose of which was to determine the depth-dependent distribution of gas-phase water in dense molecular clouds. We find that the water vapor measured toward 77 spatial positions along the face-on Orion ridge, excluding positions surrounding the outflow associated with BN/KL and IRc2, display integrated intensities that correlate strongly with known cloud surface tracers such as CN, C2H, 13CO J = 5-4, and HCN, and less well with the volume tracer N2H+. Moreover, at total column densities corresponding to AV2O to C18O integrated intensities shows a clear rise approaching the cloud surface. We show that this behavior cannot be accounted for by either optical depth or excitation effects, but suggests that gas-phase water abundances fall at large AV. These results are important as they affect measures of the true water-vapor abundance in molecular clouds by highlighting the limitations of comparing measured water-vapor column densities with such traditional cloud tracers as 13CO or C18O. These results also support cloud models that incorporate freeze out of molecules as a critical component in determining the depth-dependent abundance of water vapor.

  4. Explosive vapor detection payload for small robots

    Science.gov (United States)

    Stimac, Phil J.; Pettit, Michael; Wetzel, John P.; Haas, John W.

    2013-05-01

    Detection of explosive hazards is a critical component of enabling and improving operational mobility and protection of US Forces. The Autonomous Mine Detection System (AMDS) developed by the US Army RDECOM CERDEC Night Vision and Electronic Sensors Directorate (NVESD) is addressing this challenge for dismounted soldiers. Under the AMDS program, ARA has developed a vapor sampling system that enhances the detection of explosive residues using commercial-off-the-shelf (COTS) sensors. The Explosives Hazard Trace Detection (EHTD) payload is designed for plug-and-play installation and operation on small robotic platforms, addressing critical Army needs for more safely detecting concealed or exposed explosives in areas such as culverts, walls and vehicles. In this paper, we describe the development, robotic integration and performance of the explosive vapor sampling system, which consists of a sampling "head," a vapor transport tube and an extendable "boom." The sampling head and transport tube are integrated with the boom, allowing samples to be collected from targeted surfaces up to 7-ft away from the robotic platform. During sample collection, an IR lamp in the sampling head is used to heat a suspected object/surface and the vapors are drawn through the heated vapor transport tube to an ion mobility spectrometer (IMS) for detection. The EHTD payload is capable of quickly (less than 30 seconds) detecting explosives such as TNT, PETN, and RDX at nanogram levels on common surfaces (brick, concrete, wood, glass, etc.).

  5. Kinetics of molybdenum vapor deposition by mean of chloride decomposition: experimental results and model

    International Nuclear Information System (INIS)

    Molybdenum coatings have been prepared by thermal decomposition of volatile molybdenum chlorides formed inside the reactor. Molybdenum tetrachloride which is gradually replaced by atomic chlorine at higher temperatures is seen to be practically the only chloride of the high temperature chlorine-molybdenum interaction (T>8000C). The mechanism and rate of the deposition reaction are studied with a kinetic model based on the determination of thermodynamic equilibrium of the chlorine-molybdenum system. In the temperature range studied (800-16000C) deposition accompanied by the production of atomic chlorine is the result of tetrachloride pyrolysis. At high chlorine surface coverages (low temperature and high pressure) the reaction is thermally activated (52 Kcal/mole) and its rate is proportional to p1/4. At low coverages the reaction is first order and temperature independent. Deposition in a negative pressure gradient has been observed

  6. Impregnation, vapor phase and methanol as means of intensifying the softwood kraft pulping process

    OpenAIRE

    Enqvist, Eric

    2006-01-01

    The objective of the research was to find ways to shorten the cooking time, i.e. intensify the kraft pulping process. The reason for undertaking such a study lies in the long standing trend of ever increasing reactor size in the kraft pulping industry. The huge digester size in use presently has lead to severe problems in understanding the behavior of the chip column inside the digester. An intensified process with a drastically shorter pulping time would give a more manageable process and gr...

  7. Outcome of Transurethral Plasmakinetic Vaporization for Benign Prostatic Hyperplasia

    Scientific Electronic Library Online (English)

    Magdy, El-Tabey; Ahmed, Abo-Taleb; Ashraf, Abdelal; Mostafa Mahmod, Khalil.

    2015-04-01

    Full Text Available Purpose To assess the outcome of transurethral plasmakinetic vaporization (PKVP) in the management of benign prostatic hyperplasia (BPH). Patients and methods From August 2010 to May 2012, 60 patients with obstructive LUTS due to BPH were included in the study. All patients were evaluated by Intern [...] ational Prostate Symptom Score (IPSS), general examination, digital rectal examination, PSA, routine laboratory examinations, pelvi-abdominal ultrasound, trans-rectal ultrasound, and uroflowmetry. Patients with Qmax of 8 and a prostate volume of >40 mL underwent transurethral PKVP. Results Mean age of the patients was 66.8±4.5 years. The mean times of the operation, post-operative bladder irrigation, and post-operative catheterization were 63.8±13.9 minutes, 15.2±5.7 hours, and 23.9±5.2 hours, respectively. At 3 months of follow-up, there were significant reductions in the mean IPSS from 23.4±3.5 to 9.2±3.7 (P=0.4), mean PSA from 3.03±2.2 ng/mL to 1.2±1.04 ng/mL (P value=0.02), mean post voiding residual urine from 149.8±59.5 mL to 46.9±24.1 mL (P value

  8. Chronic mercury vapor poisoning of the lung plain radiography and high resolution CT

    Energy Technology Data Exchange (ETDEWEB)

    Park, Choong Ki; Hwang, Woo Cheol; Nho, Joon Young; Ahn, Bum Gyu; Woo, Hyo Cheol; Kim, Heung Cheol; Lee, Myoung Koo [Hallym University College of Medicine, Seoul (Korea, Republic of)

    1993-09-15

    Authors analyzed the findings of chest radiographs and high-resolution CT(HRCT) of the chronic mercury vapor poisoning in 12 patients who were diagnosed by previous working history for mercury-thermometer and high level of mercury in blood and urine. The purpose of this paper is to introduce the HRCT findings of chronic mercury vapor poisoning. Duration of mercury exposure was ranged from 10 to 41 months(mean, 21.8 months). Estimated value of serum mercury was ranged from 3.6 to 8.7 {mu} g/dl(mean, 5.3 {mu} g/dl: normal value is less than 0.5 {mu} g/dl). Estimated value of mercury in urine was ranged from 104 to 482 {mu} g/l(mean, 291.4 {mu} g/l; normal value is less than 20 {mu} g/l). Chest radiographs showed positive findings such as ground glass opacities and peribronchial cuffings in only 2 out of 12 patients, but HRCT showed positive findings such as ground glass opacities in 8 patients, peribronchial cuffings in 7 patients, centrilobular abnormalities in 5 patients, interface sign in 4 patients, interlobular septal thickening with intralobular lines in 2 patients and lobular consolidation in one patient. In conclusion, chest HRCT is superior to chest radiograph to show the pulmonary manifestation of chronic mercury vapor poisoning. In patients with chronic mercury vapor poisoning. HRCT findings of centrilobular distributed ground glass opacities and peribroncjial cuffinges are characteristic.

  9. Integration of seismic and Ground-Based InSAR displacement data: a tool to understand conduit dynamic at Stromboli Volcano

    Science.gov (United States)

    Cauchie, Léna; Di Traglia, Federico; Casagli, Nicola; Saccorotti, Gilberto

    2014-05-01

    Stromboli is an open-conduit volcano, which does not experience pressurization of the magma storage and/or plumbing system able to produce ground deformations at the scale of the volcanic edifice. For any such system, localized inflations/deflations are rather expected in response to conduit processes, such as magma convection and uprising. Indeed, detectable ground deformations at Stromboli volcano have only been observed in association with dyke intrusion at shallow depth, prior to the opening of new eruptive fractures. In this work, we present the integration of seismic and Ground-Based Interferometric Synthetic Aperture Radar (GBInSAR) system displacement data recorded at Stromboli volcano aimed at a better understanding of the geophysical signals associated with magma dynamics in an open volcanic system. A cross-analysis between the tiny GBInSAR deformations and ground displacements in the seismological frequency band (0.02-10 Hz) is performed for the period spanning 6 June 2011 - 27 August 2011, which was characterized by an activity of higher intensity than usually observed. The period under study includes seven major explosions and two lava overflows from the NE vents (1-2 August and 18 August 2011). The time series of GBInSAR displacement at the summit vents area is positively correlated with both volcanic tremor amplitude and the number and amplitude of very-long-period (VLP) signals that are associated with the Strombolian explosions. While the correlation between GBInSAR and tremor time series takes its maximum at zero lag time, the variation in frequency and energy of VLP events anticipate by a few days the inflation of the vents area and the increase of volcanic tremor. We thus suggest a general mechanism to explain the observed trend in the geophysical signals. In our model, the arrival of fresh, gas-rich magma from below enhance slug formations, promoting convection and gas transfer throughout the conduit system. At the shallowest portion of the conduit, increase of volatile content causes density decrease/expansion of the magmatic column and augmented degassing activity, which respectively induce inflation of the conduit and increased tremor amplitudes. The temporal delay between increase of VLP and tremor amplitudes/conduit inflation can be interpreted in terms of the different time scales characterizing bulk gas transfer versus slug formation and ascent.

  10. Vaporization of droplets in premixing chambers

    Science.gov (United States)

    Yule, A. J.; Chigier, N. A.

    1980-09-01

    Detailed measurements were made of the structures of turbulent fuel sprays vaporizing in heated airstreams. The measurements show the size dependent vaporization and dispersion of the droplets and the important influence of the large eddies in the turbulence. The measurements form a data base for the development of models of fuel spray vaporization. Two laser techniques were specially developed for the investigation. A laser tomography technique converts line-of-sight light scattering measurements into time averaged 'point' measurements of droplet size distribution and volume concentration. A laser anemometer particle sizing technique was further developed to permit accurate measurements of individual particle sizes and velocities, with backscatter collection of light. The experiments are combined with heat transfer models to analyze the performance of miniature thermocouples in liquid sprays.

  11. Optical fiber sensor toward pyridine vapors detection

    Science.gov (United States)

    Elosua, Cesar; Bariain, Candido; Matias, Ignacio R.; Rodriguez, Antonio; Colacio, Enrique; Salinas, Alfonso; Segura, Antonio; Fernandez, Alberto

    2008-04-01

    A novel vapochromic complex has been used to develop an optical fiber device sensitive to pyridine vapors. In solid state, this material is blue, and in the presence of pyridine vapors, its color changes to pink-white. The vapochromic material is solved in tetrahydrofuran (THF) and immobilized in a plasticized polymeric, fixing it onto a cleaved ended optical fiber pigtail by dip coating. The fabrication process was optimized in terms of number of dips and dipping speed, evaluating the final devices by dynamic range. Employing a reflection set up, the response of the sensors was registered in terms of absorbance spectrum and changes in reflected optical power. Devices showing a linear response with different vapors concentrations were obtained, with a detection limit of 1 PPM (v/v).

  12. Water vapor release from biofuel combustion

    Science.gov (United States)

    Parmar, R. S.; Welling, M.; Andreae, M. O.; Helas, G.

    2008-03-01

    We report on the emission of water vapor from biofuel combustion. Concurrent measurements of carbon monoxide and carbon dioxide are used to scale the concentrations of water vapor found, and are compared to carbon in the biofuel. Fuel types included hardwood (oak and African musasa), softwood (pine and spruce, partly with green needles), and African savanna grass. The session-averaged ratio of H2O to the sum of CO and CO2 in the emissions from 16 combustion experiments ranged from 1.2 to 3.7 on average, indicating the presence of water that is not chemically bound. This biofuel moisture content ranged from 33% in the dry African hardwood, musasa, to 220% in fresh pine branches with needles. The moisture content from fresh biofuel contributes distinctly to the water vapor in biomass burning emissions, and its influence on meteorology needs to be evaluated.

  13. Water vapor release from biofuel combustion

    Directory of Open Access Journals (Sweden)

    R. S. Parmar

    2008-03-01

    Full Text Available We report on the emission of water vapor from biofuel combustion. Concurrent measurements of carbon monoxide and carbon dioxide are used to scale the concentrations of water vapor found, and are compared to carbon in the biofuel. Fuel types included hardwood (oak and African musasa, softwood (pine and spruce, partly with green needles, and African savanna grass. The session-averaged ratio of H2O to the sum of CO and CO2 in the emissions from 16 combustion experiments ranged from 1.2 to 3.7 on average, indicating the presence of water that is not chemically bound. This biofuel moisture content ranged from 33% in the dry African hardwood, musasa, to 220% in fresh pine branches with needles. The moisture content from fresh biofuel contributes distinctly to the water vapor in biomass burning emissions, and its influence on meteorology needs to be evaluated.

  14. Vaporization Models of Varying Crude Oil Characteristics

    Directory of Open Access Journals (Sweden)

    F.N. Uzondu

    2011-01-01

    Full Text Available 2 of 0.95. The kinetic study equally showed that first order kinetic model was sufficient to quantify the vaporization rate of crude oil sample C (crude oil sample with lowest hydrocarbon concentration given the fact that the rate equation models for its vaporization from all the soil samples showed linear coefficients (R2 of between 0.611-0.87. Vaporization rate of oil sample B obeyed the second order kinetic model. Generally, the results showed the dependability of the kinetic models to varying crude oil and soil types. The models help us get good insight into providing solution to our environmental problems as it pertains to crude oil spill on land.

  15. Vapor characterization of Tank 241-C-103

    Energy Technology Data Exchange (ETDEWEB)

    Huckaby, J.L. [Westinghouse Hanford Co., Richland, WA (United States); Story, M.S. [Northwest Instrument Systems, Inc. Richland, WA (United States)

    1994-06-01

    The Westinghouse Hanford Company Tank Vapor Issue Resolution Program has developed, in cooperation with Northwest Instrument Systems, Inc., Oak Ridge National Laboratory, Oregon Graduate Institute of Science and Technology, Pacific Northwest Laboratory, and Sandia National Laboratory, the equipment and expertise to characterize gases and vapors in the high-level radioactive waste storage tanks at the Hanford Site in south central Washington State. This capability has been demonstrated by the characterization of the tank 241-C-103 headspace. This tank headspace is the first, and for many reasons is expected to be the most problematic, that will be characterized (Osborne 1992). Results from the most recent and comprehensive sampling event, sample job 7B, are presented for the purpose of providing scientific bases for resolution of vapor issues associated with tank 241-C-103. This report is based on the work of Clauss et al. 1994, Jenkins et al. 1994, Ligotke et al. 1994, Mahon et al. 1994, and Rasmussen and Einfeld 1994. No attempt has been made in this report to evaluate the implications of the data presented, such as the potential impact of headspace gases and vapors to tank farm workers health. That and other issues will be addressed elsewhere. Key to the resolution of worker health issues is the quantitation of compounds of toxicological concern. The Toxicology Review Panel, a panel of Pacific Northwest Laboratory experts in various areas, of toxicology, has chosen 19 previously identified compounds as being of potential toxicological concern. During sample job 7B, the sampling and analytical methodology was validated for this preliminary list of compounds of toxicological concern. Validation was performed according to guidance provided by the Tank Vapor Conference Committee, a group of analytical chemists from academic institutions and national laboratories assembled and commissioned by the Tank Vapor Issue Resolution Program.

  16. Vapor characterization of Tank 241-C-103

    International Nuclear Information System (INIS)

    The Westinghouse Hanford Company Tank Vapor Issue Resolution Program has developed, in cooperation with Northwest Instrument Systems, Inc., Oak Ridge National Laboratory, Oregon Graduate Institute of Science and Technology, Pacific Northwest Laboratory, and Sandia National Laboratory, the equipment and expertise to characterize gases and vapors in the high-level radioactive waste storage tanks at the Hanford Site in south central Washington State. This capability has been demonstrated by the characterization of the tank 241-C-103 headspace. This tank headspace is the first, and for many reasons is expected to be the most problematic, that will be characterized (Osborne 1992). Results from the most recent and comprehensive sampling event, sample job 7B, are presented for the purpose of providing scientific bases for resolution of vapor issues associated with tank 241-C-103. This report is based on the work of Clauss et al. 1994, Jenkins et al. 1994, Ligotke et al. 1994, Mahon et al. 1994, and Rasmussen and Einfeld 1994. No attempt has been made in this report to evaluate the implications of the data presented, such as the potential impact of headspace gases and vapors to tank farm workers health. That and other issues will be addressed elsewhere. Key to the resolution of worker health issues is the quantitation of compounds of toxicological concern. The Toxicology Review Panel, a panel of Pacific Northwest Laboratory experts in various areas, of toxicology, has chosen 19 previously identified compounds as being of potential toxicological concern. During sample job 7B, the sampling and analytical methodology was validated for this preliminary list of compounds of toxicological concern. Validation was performed according to guidance provided by the Tank Vapor Conference Committee, a group of analytical chemists from academic institutions and national laboratories assembled and commissioned by the Tank Vapor Issue Resolution Program

  17. Anomalous exchange of deuterium implanted into an oxide ceramic for protium in air vapor

    International Nuclear Information System (INIS)

    This paper describes an anomalous exchange of deuterium in an oxide ceramic, SrCe0.95Yb0.05O3-? by protium in air-vapor. The ceramic specimen was implanted with 5 keV D2+ ion beam up to saturation at room temperature and exposed to normal air introduced into the vacuum chamber. It was eventually found by means of the elastic recoil detection technique that deuterium implanted was almost completely exchanged for protium which was included in the air-vapor. On the other hand, it was found in the vice versa case that no exchange of protium implanted into the ceramic for deterium in D2O vapor took place. The mechanism for such an anomalous isotope replacement is discussed. (orig.)

  18. Electron-enhanced adsorption of water vapor on the platinum surface

    International Nuclear Information System (INIS)

    A decrease of water vapor partial pressure in a vacuum chamber at the electron bombardment (200-2500 eV) of the polycrystalline platinum surface has been observed by means of mass spectrometry. The pressure decrease rate is proportional to the electron current and the water vapor pressure. The effect observed is shown to be related with dissociation of the adsorbed water molecules under the electron impact and with the additional water vapor adsorption. Based on the comparison between the electron-enhanced adsorption rate and the coefficient of inelastic electron scattering as functions of the primary electron energy, the conclusion is arrived at that secondary electrons play an important role in dissociation of adsorbed molecules

  19. High temperature thermodynamics and vaporization of the zirconium--niobium--oxygen system

    International Nuclear Information System (INIS)

    The vaporization behavior of the Zr--Nb--O system was studied by means of successive vaporization, Knudsen effusion-target collection experiments, and mass spectrometric analysis of the vapors effusing from a Knudsen crucible. The successive vaporization experiments were performed on two ternary samples in open crucibles. X-ray powder diffraction patterns of the residues and x-ray fluorescence analysis of the condensates and residues indicated the preferential vaporization of niobium-containing species with the composition of the residue subsequently becoming closer to that of congruently vaporizing ZrO/sub 2-x/. The Knudsen effusion-target collection experiments were employed on two samples, pure NbO2(s) and a two-phase ZrO2--NbO2 mixture, in order to obtain information on the activity of NbO2 in the two-phase mixture. Second law enthalpies and entropies of sublimation as well as third law enthalpies were obtained for both systems. The vaporization behaviors of five compositions in the Zr--Nb--O system, NbO2, NbO, a ZrO2--NbO2 two-phase mixture, Nb2O5, and Zr6Nb2O17, were investigated. Above Nb2O5 and the fully oxidized Zr6Nb2O17 oxygen is preferentially lost; over NbO2, the two-phase ZrO2--NbO2 system, and NbO the principal gaseous species is NbO2

  20. High temperature thermodynamics and vaporization of the zirconium--niobium--oxygen system

    Energy Technology Data Exchange (ETDEWEB)

    Rinehart, G.H.

    1978-05-18

    The vaporization behavior of the Zr--Nb--O system was studied by means of successive vaporization, Knudsen effusion-target collection experiments, and mass spectrometric analysis of the vapors effusing from a Knudsen crucible. The successive vaporization experiments were performed on two ternary samples in open crucibles. X-ray powder diffraction patterns of the residues and x-ray fluorescence analysis of the condensates and residues indicated the preferential vaporization of niobium-containing species with the composition of the residue subsequently becoming closer to that of congruently vaporizing ZrO/sub 2-x/. The Knudsen effusion-target collection experiments were employed on two samples, pure NbO/sub 2/(s) and a two-phase ZrO/sub 2/--NbO/sub 2/ mixture, in order to obtain information on the activity of NbO/sub 2/ in the two-phase mixture. Second law enthalpies and entropies of sublimation as well as third law enthalpies were obtained for both systems. The vaporization behaviors of five compositions in the Zr--Nb--O system, NbO/sub 2/, NbO, a ZrO/sub 2/--NbO/sub 2/ two-phase mixture, Nb/sub 2/O/sub 5/, and Zr/sub 6/Nb/sub 2/O/sub 17/, were investigated. Above Nb/sub 2/O/sub 5/ and the fully oxidized Zr/sub 6/Nb/sub 2/O/sub 17/ oxygen is preferentially lost; over NbO/sub 2/, the two-phase ZrO/sub 2/--NbO/sub 2/ system, and NbO the principal gaseous species is NbO/sub 2/.