WorldWideScience

Sample records for vapor conduit means

  1. Drill pipes and casings utilizing multi-conduit tubulars

    Energy Technology Data Exchange (ETDEWEB)

    Curlett, H.B.

    1989-01-24

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

  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. 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

  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. 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

  8. 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.

  9. 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

  10. 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''...

  11. 30 CFR 18.39 - Hose conduit.

    Science.gov (United States)

    2010-07-01

    ...ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ...Hose conduit shall be provided for mechanical protection of all machine cables that are exposed to damage. Hose conduit shall be flame...

  12. 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.

  13. Ductile compaction in volcanic conduits

    Science.gov (United States)

    Wadsworth, Fabian; Vasseur, Jeremie; Lavallée, Yan; Scheu, Bettina; Dingwell, Donald

    2014-05-01

    Silicic magmas typically outgas through connected pore and crack networks with a high gas permeability without the need for decoupled movement of pores in the melt. It is the efficiency with which this process can occur which governs the pressure in the pore network. However, such a connected coupled network is generally mechanically unstable and will relax until volume equilibrium when the pores become smaller and isolated. Consequently, gas permeability can be reduced during densification. Cycles of outgassing events recorded in gas monitoring data show that permeable flow of volatiles is often transient, which is interpreted to reflect magma densification and the closing of pore-networks. Understanding the timescale over which this densification process occurs is critical to refining conduit models that seek to predict the pressure evolution in a pore-network leading to eruptions. We conduct uniaxial compaction experiments to parameterize non-linear creep and relaxation processes that occur in magmas with total pore fractions 0.2-0.85. We analyze our results by applying both viscous sintering and viscoelastic deformation theory to test the applicability of currently accepted models to flow dynamics in the uppermost conduit involving highly porous magmas. We show that purely ductile compaction can occur rapidly and that pore networks can close over timescales analogous to the inter-eruptive periods observed during classic cyclic eruptions such as those at Soufriere Hills volcano, Montserrat, in 1997. At upper-conduit axial stresses (0.1-5 MPa) and magmatic temperatures (830-900 oC), we show that magmas can evolve to porosities analogous to dome lavas erupted at the same volcano. Such dramatic densification events over relatively short timescales and in the absence of brittle deformation show that permeable flow will be inhibited at upper conduit levels. We therefore propose that outgassing is a key feature at many silicic volcanoes and should be incorporated into conduit flow models.

  14. Conduits for Coronary Bypass: Strategies

    OpenAIRE

    Barner, Hendrick B

    2013-01-01

    Strategic planning is integral to any operation but complexity varies immensely and therefore the effort necessary to create the optimal plan. The previous three reports have discussed individual conduits and herein is an attempt to present approaches to common situations which the author favors. Although much has been learned over 45 years about use and subsequent behavior of venous and arterial grafts we continue to learn and, as a result, evolve new strategies or modify those now popular. ...

  15. Drill pipes and casings utilizing multi-conduit tubular; Flerkanals roerstreng

    Energy Technology Data Exchange (ETDEWEB)

    Curlett, H.B.

    1997-04-23

    The invention relates to a multi-conduit tubular having fluid conduits and electrical conduits, with associated surface fluid and electrical commutators, and downhole sensors for providing surface monitors with instantaneous formation data. Each tubular includes a plurality of uniform linear conduits there through, with a gasket seal plate interposed between joined tubular for assuring a high pressure seal between joined conduits. the seal plate includes an intermediate electrical connector for connecting electrical conduit connectors of one tubular to another. A coupling collar with uniform diameter internal coarse and fine threads joins the tubular ends having similar threads by differential thread action without respective tubular rotation. Each tubular end includes an inter-engaging index recess and index lug, and drive recesses and lugs for maintaining angular registry of the tubular string and for driving one drill tubular with another. A fluid commutator includes a rotating shaft with passages connected to the tubular conduits, and rotating in a manifold having annular grooves in communication with the shaft passages and external fluid sources. An adaptor couples each commutator shaft passage to one or more tubular conduits. Slip rings on a quill shaft and stationary brush means provide electrical continuity from the electrical conduit wires to surface equipment. A cross-over sub includes formation parameter sensors and telemetry equipment in a blocked off portion of a fluid conduit. An annular accumulator connected with the well bore annulus applies a pressure thereto in response to downhole sensors to change the effective density of the drill mud. The multi-conduit tubular is further adapted for use as a well casing to provide downhole access of a plurality of fluids and electrical parameter sensors. 28 figs.

  16. 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.

  17. 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

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

    Directory of Open Access Journals (Sweden)

    Meduoye Ayo

    2011-06-01

    Full Text Available 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 with an average of 4.3 ± 0.45 years post-operatively to evaluate valve function, calcification, and the diameter of the conduit. Results Implantation in 67 patients represented a follow-up of 371.3 patient-year. Males were 60% of the operated population, with a mean age of 67.9 ± 1.3 years (range 34.1-83.8 years, 21 of them below the age of 65. After a mean follow-up of 7.1 ± 0.3 years (range of 2.2-10.5 years, more than 50% of the survivors were in NYHA I/II and more than 60% of the survivors were angina-free (CCS 0. The overall 10-year survival following replacement of the aortic valve and root was 51%. During this period, 88% of patients were free from valved-conduit related complications leading to mortality. Post-operative echocardiography studies showed no evidence of stenosis, dilatation, calcification or thrombosis. Importantly, during the 10-year follow-up period no failures of the valved conduit were reported, suggesting that the tissue of the conduit does not structurally change (histology of one explant showed normal cusp and conduit. Conclusions The No-React® BioConduit composite stentless aortic valved conduit provides excellent long-term clinical results for aortic root replacement with few prosthesis-related complications in the first post-operative decade.

  19. 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.

  20. 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

  1. 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.

  2. MRI of the heart following implantation of a left ventricular apico-aortic conduit; Kernspintomografie zur umfassenden Untersuchung des Herzens nach Implantation von linksventrikulaeren apikoaortalen Conduits

    Energy Technology Data Exchange (ETDEWEB)

    Ruhl, K.M.; Katoh, M.; Guenther, R.W.; Krombach, G.A. [Technische Hochschule Aachen (Germany). Klinik fuer Radiologische Diagnostik; Langebartels, G.; Autschbach, R. [Technische Hochschule Aachen (Germany). Klinik fuer Thorax-, Herz- und Gefaesschirurgie

    2007-06-15

    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.)

  3. 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.)

  4. 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.)

  5. 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.

  6. Method and device for isotope-selective excitation of gaseous or vaporous uranium hexafluoride by means of laser radiation

    International Nuclear Information System (INIS)

    The light generated by triple Raman scattering of an iodine laser in liquid and/or solid N has a width of line corresponding nearly exactly to the half-width of the relevant absorption lines of the subcooled UF6. By a corresponding shift of frequencies this line isotope-specifically overlaps with an absorption line of the UF6 molecules, so that these become excited and capable of being separated by means of physical and chemical methods of separation. (DG)

  7. 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.

  8. 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.

  9. 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)

  10. 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.

  11. Dispersive Hydrodynamics in Viscous Fluid Conduits

    CERN Document Server

    Lowman, Nicholas K

    2013-01-01

    The evolution of the interface separating a conduit of light, viscous fluid rising buoyantly through a heavy, more viscous, exterior fluid at small Reynolds numbers is governed by the interplay between nonlinearity and dispersion. Previous authors have proposed an approximate model equation based on physical arguments, but a precise theoretical treatment for this two fluid system with a free boundary is lacking. Here, a derivation of the interfacial equation via a multiple scales, perturbation technique is presented. Perturbations about a state of vertically uniform, laminar conduit flow are considered in the context of the Navier-Stokes equations with appropriate boundary conditions. The ratio of interior to exterior viscosities is the small parameter used in the asymptotic analysis, which leads systematically to a maximal balance between buoyancy driven, nonlinear self-steepening and viscous, interfacial stress induced, nonlinear dispersion. This results in a scalar, nonlinear partial differential equation ...

  12. 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

  13. 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....

  14. 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.

  15. 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.

  16. 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

  17. 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)

  18. 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.

  19. Nanofibrous nerve conduit-enhanced peripheral nerve regeneration.

    Science.gov (United States)

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

    2014-05-01

    Fibre structures represent a potential class of materials for the formation of synthetic nerve conduits due to their biomimicking architecture. Although the advantages of fibres in enhancing nerve regeneration have been demonstrated, in vivo evaluation of fibre size effect on nerve regeneration remains limited. In this study, we analyzed the effects of fibre diameter of electrospun conduits on peripheral nerve regeneration across a 15-mm critical defect gap in a rat sciatic nerve injury model. By using an electrospinning technique, fibrous conduits comprised of aligned electrospun poly (?-caprolactone) (PCL) microfibers (981?±?83 nm, Microfiber) or nanofibers (251?±?32 nm, Nanofiber) were obtained. At three months post implantation, axons regenerated across the defect gap in all animals that received fibrous conduits. In contrast, complete nerve regeneration was not observed in the control group that received empty, non-porous PCL film conduits (Film). Nanofiber conduits resulted in significantly higher total number of myelinated axons and thicker myelin sheaths compared to Microfiber and Film conduits. Retrograde labeling revealed a significant increase in number of regenerated dorsal root ganglion sensory neurons in the presence of Nanofiber conduits (1.93 ± 0.71 × 10(3) vs. 0.98 ± 0.30 × 10(3) in Microfiber, p?conduit group compared to the Microfiber group. This study demonstrated the impact of fibre size on peripheral nerve regeneration. These results could provide useful insights for future nerve guide designs. PMID:22700359

  20. Proximal conduit obstruction after Sano modified Norwood procedure.

    Science.gov (United States)

    Nigro, John J; Bart, Robert D; Derby, Christopher D; Sklansky, Mark S; Starnes, Vaughn A

    2005-11-01

    Sano and colleagues recently described a modification of first stage palliation for hypoplastic left heart syndrome utilizing a right ventricle to pulmonary artery conduit. Preliminary results are favorable, but experience with this technique is limited. We report a case of sudden death due to obstruction of the proximal conduit by fibrointimal hyperplasia. This case of lethal conduit obstruction presented 3 months after initial palliation. Early cardiac catheterization and second stage palliation may be necessary to minimize the risk of such adverse events after the Sano modification. PMID:16242490

  1. 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

  2. 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.

  3. 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.

  4. 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)

  5. 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)

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. 26 CFR 1.881-3 - Conduit financing arrangements.

    Science.gov (United States)

    2010-04-01

    ... state (the source state) to a resident of the other state from tax in the source state. Example 1... income from U.S. sources under section 861(a)(4) subject to the 30 percent gross tax imposed by § 1.881-2... 26 Internal Revenue 9 2010-04-01 2010-04-01 false Conduit financing arrangements. 1.881-3...

  11. 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.

  12. Aorto-conduit fistula developing four years after esophagectomy.

    Science.gov (United States)

    Strong, S; Higgs, S; Streets, C; Titcomb, D; Barham, P; Blazeby, J; Hollowood, A

    2012-01-01

    A 71 year old lady was treated for a squamous cell carcinoma of the oesophagus with neo-adjuvant chemotherapy followed by a two phase Ivor-Lewis oesophagectomy with two field lymphadenectomy. She presented four years later with life threatening bleeding from a fistula between the thoracic aorta and the gastric conduit, which was treated successfully with a thoracic aortic stent. PMID:24960784

  13. CODUL EUROPEAN DE BUN? CONDUIT? ADMINISTRATIV? ?I FENOMENUL ADMINISTRATIV ROMÂNESC

    Directory of Open Access Journals (Sweden)

    Alina Nicu

    2006-05-01

    Full Text Available Pour vivre parmi les membres d¢une certaine collectivité humaine, il est absolument nécessaire de connaître et respecter les valeurs fondamentales de celle-ci. Il est nécessaire également de respecter et d’appliquer les lignes de conduite importées par les normes juridiques réglementant les relations sociales qui se forment dans la collectivité respective pour realiser et protéger ces valeurs. Le peuple roumain, étant impliqué dans la procedure d¢adhésion à l¢Union européenne, a le devoir de connaître le droit communautaire. Le législateur roumain a la mission d'élaborer et d'adopter des lois compatibles avec les normes juridiques communautaires. L'exécutif doit agir pour que les lois soient appliques par tous ceux qui l’exécutif vivent en Roumanie. Par couséquence, il est absolument nécessaire de réformer l'administration publique roumaine de sorte que la relation fonctionnaire public et autres agents de l'administration publique – citoyen destinataire et bénéficiaire de la décision administrative et de la prestation administrative, soit conforme aux standards de l'Union européenne. Cet ouvrage a comme but de présenter en quelle mesure les règles écrites dans le Code européen de bonne conduite administrative peuvent être un modèle pour le législateur roumain. Même si le Code européen de bonne conduite administrative est un document rédigé pour établir les principes généraux à observer dans les relations entre les institutions communautaires européennes et le public, nous considerons qu'il y a plusieurs raisons pour considérer ce Code comme un modèle digne d'être suivi dans l'activité du législateur roumain. Parmi ces raisons, se trouve la performance d'établir le contenu de la base légale pour la bonne conduite administrative utilisant seulement vingt-sept articles dans lesquels on précise les principes généraux pour ce domaine d'activité sociale. Donc, le caractère concis et pourtant explicite du texte est un modèle pour une loi roumaine concernant la bonne conduite administrative ou pour un chapitre du Code administratif, chapitre ayant comme sujet la bonne conduite administrative. Une autre raison est celle que des principes comme „légitimité”, „absence de discri­mination”, „la proportionnalité”, „absense d'abus de pouvoir”, „impartialité et indépendance”, „objectivité”, „équité”, „confiance légitime, cohérence et conseil” et „courtoisie” doivent être présents parmi les principes fondamentaux de l'administration publique, quel que soit le pays dont il s'agit.

  14. 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.

  15. 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)

  16. 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.

  17. 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.

  18. Grading complication following radical cystectomy and ileal conduit for bladder cancer using clavien grading system

    International Nuclear Information System (INIS)

    Objective: To determine the 30-day complication rate of radical cystectomy and urinary diversion using a validated system. Study Design: An analytical descriptive study. Place and Duration of Study: The Aga Khan University Hospital, Karachi, from 1990 to 2010. Methodology: Patients who had undergone ileal conduit (IC) formation, following radical cystectomy (RC) for muscle invasive transitional cell carcinoma, were studied, using a prospectively maintained data base. Basic details were determined, complications were noted and graded according to the modified Clavien grading system (CG). Results were presented using descriptive statistics. Results: Of all the RC performed at this hospital 89 patients received IC. Of them 75 were male and 14 female. Mean age was 60 years. Mean duration of hospital stay was 14 days. Ten patients each received pre-operative chemotherapy and radiotherapy, respectively. Mean duration of surgery was 8.2 hours, with mean estimated blood loss of 1334 ml. Preoperative radiotherapy was associated with more complications. No other factor like ASA, co-morbidities, blood loss or duration of stay influenced the complications. Fifty patients (56.2%) did not have any complications. Most common complication of wound infection was seen in 7 patients (CG-2), followed by uretero-ileal leakage in 5, requiring percutaneous intervention under local anaesthesia (GC-3a). Mortality rate was 4.5%, classified as CG-V. Conclusion: Radical cystectomy with Ileal conduit is a major procedure with a good safety profile at this institute. Long term follow up is still needed to evaluate delayed complications and quality of life. (author)

  19. CODUL EUROPEAN DE BUN? CONDUIT? ADMINISTRATIV? ?I FENOMENUL ADMINISTRATIV ROMÂNESC

    OpenAIRE

    Alina Nicu

    2006-01-01

    Pour vivre parmi les membres d¢une certaine collectivité humaine, il est absolument nécessaire de connaître et respecter les valeurs fondamentales de celle-ci. Il est nécessaire également de respecter et d’appliquer les lignes de conduite importées par les normes juridiques réglementant les relations sociales qui se forment dans la collectivité respective pour realiser et protéger ces valeurs. Le peuple roumain, étant impliqué dans la procedure d¢adhésion à l¢Union européenne, a le devoir de ...

  20. 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...

  1. 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.

  2. 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.

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

    Scientific Electronic Library Online (English)

    Karine F., Meyer; Mauricio, Macedo; Humberto, S. Filho; Thais R., Pinto; Leonan T., Galvao; Quirino C., Meneses.

    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 usin [...] g 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.

  4. 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

  5. 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.

  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. 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 ...

  8. 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...

  9. Rotational pectoral musculocutaneous flap for the repair of gastric conduit necrosis in cervical esophagogastrostomy.

    Science.gov (United States)

    Kim, Jae Jun; Park, Jae Kil; Hwang, Sun Jin; Moon, Seok Whan

    2012-12-01

    We experienced a case of wide necrosis of the cervical gastric conduit during esophageal cancer surgery. We attempted to repair this defect with various methods including conservative care, stents two times, and sternocleidomastoid muscle flap without successful results. Finally, we were able to reconstruct the gastric conduit defect with rotational pectoralis major musculocutaneous (PMM) flap. PMM flap is thought to be a reconstruction method applicable to the intractable gastric conduit defect. PMID:23230559

  10. Rotational pectoral musculocutaneous flap for the repair of gastric conduit necrosis in cervical esophagogastrostomy

    OpenAIRE

    Kim, Jae Jun; Park, Jae Kil; Hwang, Sun Jin; Moon, Seok Whan

    2012-01-01

    We experienced a case of wide necrosis of the cervical gastric conduit during esophageal cancer surgery. We attempted to repair this defect with various methods including conservative care, stents two times, and sternocleidomastoid muscle flap without successful results. Finally, we were able to reconstruct the gastric conduit defect with rotational pectoralis major musculocutaneous (PMM) flap. PMM flap is thought to be a reconstruction method applicable to the intractable gastric conduit def...

  11. 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

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. A sampling plan for conduit-flow karst springs: Minimizing sampling cost and maximizing statistical utility

    Science.gov (United States)

    Currens, J.C.

    1999-01-01

    Analytical data for nitrate and triazines from 566 samples collected over a 3-year period at Pleasant Grove Spring, Logan County, KY, were statistically analyzed to determine the minimum data set needed to calculate meaningful yearly averages for a conduit-flow karst spring. Results indicate that a biweekly sampling schedule augmented with bihourly samples from high-flow events will provide meaningful suspended-constituent and dissolved-constituent statistics. Unless collected over an extensive period of time, daily samples may not be representative and may also be autocorrelated. All high-flow events resulting in a significant deflection of a constituent from base-line concentrations should be sampled. Either the geometric mean or the flow-weighted average of the suspended constituents should be used. If automatic samplers are used, then they may be programmed to collect storm samples as frequently as every few minutes to provide details on the arrival time of constituents of interest. However, only samples collected bihourly should be used to calculate averages. By adopting a biweekly sampling schedule augmented with high-flow samples, the need to continuously monitor discharge, or to search for and analyze existing data to develop a statistically valid monitoring plan, is lessened.Analytical data for nitrate and triazines from 566 samples collected over a 3-year period at Pleasant Grove Spring, Logan County, KY, were statistically analyzed to determine the minimum data set needed to calculate meaningful yearly averages for a conduit-flow karst spring. Results indicate that a biweekly sampling schedule augmented with bihourly samples from high-flow events will provide meaningful suspended-constituent and dissolved-constituent statistics. Unless collected over an extensive period of time, daily samples may not be representative and may also be autocorrelated. All high-flow events resulting in a significant deflection of a constituent from base-line concentrations should be sampled. Either the geometric mean or the flow-weighted average of the suspended constituents should be used. If automatic samplers are used, then they may be programmed to collect storm samples as frequently as every few minutes to provide details on the arrival time of constituents of interest. However, only samples collected bihourly should be used to calculate averages. By adopting a biweekly sampling schedule augmented with high-flow samples, the need to continuously monitor discharge, or to search for and analyze existing data to develop a statistically valid monitoring plan, is lessened.

  1. 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

  2. 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...

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Limitations of nerve repair of segmental defects using acellular conduits.

    Science.gov (United States)

    Berrocal, Yerko A; Almeida, Vania W; Levi, Allan D

    2013-09-01

    The authors present the case of a 20-year-old man who, 3 months after his initial injury, underwent repair of a 1.7-cm defect of the ulnar nerve at the wrist; repair was performed with an acellular nerve allograft. Given the absence of clinical or electrophysiological recovery at 8 months postrepair, the patient underwent reexploration, excision of the "regenerated cable," and rerepair of the ulnar nerve with sural nerve autografts. Histology of the cable demonstrated minimal axonal regeneration at the midpoint of the repair. At the 6- and 12-month follow-ups of the sural nerve graft repair, clinical and electrophysiological evidence of both sensory and motor reinnervation of the ulnar nerve and associated hand muscles was demonstrated. In this report, the authors describe a single case of failed acellular nerve allograft and correlate the results with basic science and human studies reporting length and diameter limitations in human nerve repair utilizing grafts or conduits devoid of viable Schwann cells. PMID:23746100

  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. 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

  10. Investigation of entrance length in circular and noncircular conduits by computational fluid dynamics simulation

    Directory of Open Access Journals (Sweden)

    Pimpun Tongpun

    2014-08-01

    Full Text Available This study estimated entrance length of circular and noncircular conduits, including circle, triangle, square and hexagon cross-sectional conduit, by using computational fluid dynamics (CFD. For simulation condition, the length of noncircular conduit was 10 m and the hydraulic diameter was 0.2 m. The laminar flow with Reynolds number of 500 and turbulent flow with Reynolds number of 50,000 were applied to investigate water flow in conduits. The governing equations were solved iteratively by using ANSYS FLUENT 14.0. For turbulent flow simulation, standard k-epsilon and RNG k-epsilon model were employed to simulate turbulence. The preliminary results were validated by comparison with theoretical data. At first, grid independency was evaluated to optimize the model. Norm* was employed to investigate the entrance length, which is related to velocity. The simulated results revealed that the entrance length for laminar flow was longer than turbulent flow.

  11. 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.

  12. 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.

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

    OpenAIRE

    Hassan A. Abol-Enein; Ausama S. Abdul-Muhsin; Yousuf M. Alhallaq

    2008-01-01

    OBJECTIVES To revise indications, case fatality ratio, and postoperative early and late complications of ileal conduit as a method of urinary diversion. METHODS 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, peroperative findings, and postoperative follow-up data were reviewed. RESULTS In 200 patients aged 29-7...

  14. 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.

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

    OpenAIRE

    Yu, Tao; 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...

  16. 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

  17. 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

  18. 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.

  19. 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)

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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 ...

  5. 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.

  6. Development and performance test results of 50 kA vapor-cooled current lead for ITER

    International Nuclear Information System (INIS)

    JAERI has developed 50 kA current leads for the International Thermonuclear Experimental Reactor (ITER). The Center Solenoid (CS) Model Coil program is under way by means of international collaboration in ITER-EDA. The CS model coil is being developed for ITER CS coil and is for demonstration for ITER construction. The performance test of the CS model coil will be carried out at the JAERI ITER common test facility (CTF). The current lead consists of the vertical lead and the connection lead. The vertical lead is a vapor-cooled type and has a cable-in-conduit geometry. The vertical lead was designed with a heat leak of 1.2 W/kA at a helium flow rate of 0.06 g/(s·kA). The measured heat leak satisfied the designed value. The connection lead was made from copper pipe soldered with NbTi superconducting wires. The pipe was stabilized by the superconducting wires and a cooling channel. The current lead was operated up to 60 kA. The design and the performance test results of 50 kA current leads are reported. The results meet the specifications for the CS model coil test and for the ITER real machine. (author)

  7. 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.

  8. Midterm results of bovine jugular vein conduit for right ventricular outflow tract reconstruction

    International Nuclear Information System (INIS)

    Objective: To evaluate the midterm results of Contegra conduit. Methods: The retrospective study comprised patient record at Aga Khan University Hospital, Karachi, of conduits implanted between May 2007 and June 2012. Data collection was made from the clinical notes and from serial echocardiograms by a single cardiologist. The last followup echocardiography was done at the time of data collection in June 2012. SPSS 19 was used for statistical analysis. Results: A total of 18 conduits had been implanted (16-22mm) during the study period. Median age at the time of surgery was 9 years (range: 2.5-16 years). Early mortality was seen in 3 (16.66%) patients, but none was Contegra related. Of the remaining 15 patients, 2 (13.33%) with a diagnosis of Pulmonary Atresia-Ventricular Septal Defect with hypoplastic peripheral Pulmonary Arteries (PA), developed severe distal pressure gradient (50mmHg) across Contegra over a median period of 18 months (range: 12-24 months), with resultant severe regurgitation and needed percutaneous intervention. There was no thrombosis, calcification, anuerysmal dilation or late deaths. Conclusion: At midterm followup, Contegra conduit was associated with low re-intervention rates with satisfactory haemodynamic results. However, long-term durability must be determined for this conduit, especially in patients with Pulmonary Atresia-Ventricular Septal Defect with hypoplastic peripheral Pulmonary Arteries. (author)

  9. 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

  10. 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

  11. Vaporization of ThC and (Th,U)C

    International Nuclear Information System (INIS)

    Vaporization behavior of thorium carbide fuels, ThC and (Th,U)C, was studied by high temperature mass spectrometry. Both ThC and (Th,U)C were prepared by carbothermic reduction. Vapor pressure of U(g) or, U(g) and Th(g) was measured by using a graphite-linered tantalum Knudsen cell. Besides the absolute vapor pressure, the partial molal enthalpy of vaporization and the partial molar Gibbs energy of Th were evaluated for ThC1±x. For (Th,U)C, activities of ThC and UC in addition to absolute vapor pressures were evaluated. Then, compatibility of ThC with either Ni, Fe or Cr was examined by means of an EPMA analysis of the reaction zone. Only Ni showed significant reaction with ThC. Three reaction layers were identified. Finally, preparation of high density ThC pellet by means of sintering was studied. (author)

  12. 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.

  13. 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.

  14. The grain-size distribution of pyroclasts: Primary fragmentation, conduit sorting or abrasion?

    Science.gov (United States)

    Kueppers, U.; Schauroth, J.; Taddeucci, J.

    2013-12-01

    Explosive volcanic eruptions expel a mixture of pyroclasts and lithics. Pyroclasts, fragments of the juvenile magma, record the state of the magma at fragmentation in terms of porosity and crystallinity. The grain size distribution of pyroclasts is generally considered to be a direct consequence of the conditions at magma fragmentation that is mainly driven by gas overpressure in bubbles, high shear rates, contact with external water or a combination of these factors. Stress exerted by any of these processes will lead to brittle fragmentation by overcoming the magma's relaxation timescale. As a consequence, most pyroclasts exhibit angular shapes. Upon magma fragmentation, the gas pyroclast mixture is accelerated upwards and eventually ejected from the vent. The total grain size distribution deposited is a function of fragmentation conditions and transport related sorting. Porous pyroclasts are very susceptible to abrasion by particle-particle or particle-conduit wall interaction. Accordingly, pyroclastic fall deposits with angular clasts should proof a low particle abrasion upon contact to other surfaces. In an attempt to constrain the degree of particle interaction during conduit flow, monomodal batches of washed pyroclasts have been accelerated upwards by rapid decompression and subsequently investigated for their grain size distribution. In our set-up, we used a vertical cylindrical tube without surface roughness as conduit. We varied grain size (0.125-0.25; 0.5-1; 1-2 mm), porosity (0; 10; 30 %), gas-particle ratio (10 and 40%), conduit length (10 and 28 cm) and conduit diameter (2.5 and 6 cm). All ejected particles were collected after settling at the base of a 3.3 m high tank and sieved at one sieve size below starting size (half-?). Grain size reduction showed a positive correlation with starting grain size, porosity and overpressure at the vent. Although milling in a volcanic conduit may take place, porous pyroclasts are very likely to be a primary product of magma fragmentation at or close to the fragmentation level. Given the high abrasiveness of pumice, hemispherical clasts should be observed if clast break-up followed efficient clast abrasion. As a consequence, finer grained pyroclastic fall deposits do not necessarily proof efficient secondary fragmentation in the conduit but may rather reveal the influence of conduit length on 'What size of pyroclasts can be erupted'?

  15. 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.

  16. 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

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Jean Vigo's "Zéro De Conduite" and the Spaces of Revolt

    Science.gov (United States)

    Vanobbergen, Bruno; Grosvenor, Ian; Simon, Frank

    2014-01-01

    In this article we will contribute to the contemporary theoretical debate about film by considering, from a history-of-education perspective, the film "Zéro de conduite" by Jean Vigo (1905--1934). This film is classified under the umbrella of "poetic realism": a product of "cinéma de gauche" and an avant-gardist,…

  3. 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.

  4. 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.

  5. 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.

  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. Water vapor diffusion membranes

    Science.gov (United States)

    Holland, F. F., Jr.; Smith, J. K.

    1974-01-01

    The program is reported, which was designed to define the membrane technology of the vapor diffusion water recovery process and to test this technology using commercially available or experimental membranes. One membrane was selected, on the basis of the defined technology, and was subjected to a 30-day demonstration trial.

  8. 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.

  9. 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.

  10. A method of gastric conduit elevation via the posterior mediastinal pathway in thoracoscopic subtotal esophagectomy

    Directory of Open Access Journals (Sweden)

    Hirahara Noriyuki

    2012-01-01

    Full Text Available Abstract Background Despite efforts to improve surgical techniques, serious complications still sometimes occur. Use of a physiological posterior mediastinal pathway has increased given advances such as automated anastomotic devices and a reduction in the incidence of anastomotic sufficiency. Until now the gastric conduit created has been protected by an echo probe cover and, sown to the ventral side of polyester tape placed through the abdomen to the neck, and then blindly elevated to the neck. We report on a new method of gastric conduit elevation. Methods Two 60-cm lengths polyester tape are ligated at both ends to form a loop. An echo probe cover of 10 cm in diameter and 50 cm in length is prepared and the tip cut off, forming a cylinder. The knots in the previously looped polyester tape are inserted into the echo probe cover. The looped polyester tape and echo probe cover is ligated with silk approximately 5 cm in front of the knots on both sides. After dissection is carried out according to practice, the previously crafted polyester tape is inserted into the chest cavity. One end of polyester tape is fixed to the distal esophageal stump with the clips, with the opposite end fixed to the proximal esophageal stump. The echo probe cover that connects the proximal esophagus and distal esophagus is monitored for the presence of creases along the long axis to ensure there are no twists in the echo probe cover. We carry out a laparoscopic-assisted perigastric lymph node dissection, make a small skin incision, and guide part of the thoracic esophagus and stomach outside the body. Either one of the two lengths of polyester tape is connected to the gastric conduit. By pulling up this length of polyester tape from the neck, the gastric conduit can pass through the echo probe cover and be elevated to the neck. Results No perioperative complications such as bleeding or difficulty of the gastric conduit elevation were recognized with this method. Conclusions This method is considered to serve as a useful technique for gastric conduit elevation.

  11. 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.

  12. 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

  13. 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)

  14. TPX superconducting cable-in-conduit 1995 design and development progress

    International Nuclear Information System (INIS)

    A unique feature of the magnet system for the Tokamak Physics Experiment (TPX) is that all the magnets are superconducting. With the exception of the outer poloidal coils, the magnet system uses Nb3Sn cable-in-conduit conductor; the outer poloidal coils use Nb-Ti cable-in-conduit conductor. We describe the current TPX conductor design and present a progress report on the conductor development. Our strand development contracts have resulted in demonstrating that at least two vendors can produce Nb3Sn strand which meets the TPX specification. Subcable testing gives confidence that the TPX conductor will satisfy the magnet operational requirements. Fabrication of full-size conductors is underway and tests on these will give verification that the TPX conductor meets the operational requirements. Our industrial cabling and sheathing contract to produce demonstration conductor using copper strands is exploring a production technique that differs from the conventional tube mill approach

  15. Solving the flow fields in conduits and networks using energy minimization principle with simulated annealing

    CERN Document Server

    Sochi, Taha

    2014-01-01

    In this paper, we propose and test an intuitive assumption that the pressure field in single conduits and networks of interconnected conduits adjusts itself to minimize the total energy consumption required for transporting a specific quantity of fluid. We test this assumption by using linear flow models of Newtonian fluids transported through rigid tubes and networks in conjunction with a simulated annealing (SA) protocol to minimize the total energy cost. All the results confirm our hypothesis as the SA algorithm produces very close results to those obtained from the traditional deterministic methods of identifying the flow fields by solving a set of simultaneous equations based on the conservation principles. The same results apply to electric ohmic conductors and networks of interconnected ohmic conductors. Computational experiments conducted in this regard confirm this extension. Further studies are required to test the energy minimization hypothesis for the non-linear flow systems.

  16. 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.

  17. 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

  18. 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)

  19. 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...

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

    OpenAIRE

    Fouad M. Qureshi; 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...

  1. 3D Printed Trileaflet Valve Conduits Using Biological Hydrogels and Human Valve Interstitial Cells

    OpenAIRE

    Duan, Bin; Kapetanovic, Edi; Hockaday, Laura A.; Jonathan T. Butcher

    2013-01-01

    Tissue engineering has great potential to provide a functional de novo living valve replacement capable of integration with host tissue and growth. Among various valve conduit fabrication techniques, 3D bioprinting enables deposition of cells and hydrogels into 3D constructs with anatomical geometry and heterogeneous mechanical properties. Successful translation of this approach is however constrained by the dearth of printable and biocompatible hydrogel materials. Furthermore, it is not know...

  2. Submarine Cascais Canyon as a sediment conduit to the deep sea : comparison with adjacent slopes

    OpenAIRE

    Costa, A.M.; Mil-Homens, Mário; Lebreiro, Susana; Stigter De, H.; Richter, T.; Boer, Wim de; Trancoso, Maria Ascensão; Melo, Zenaida; Mouro, F.; Mateus, M.

    2009-01-01

    Submarine canyons are known to be important conduits that trap, accumulate and deliver both natural and anthropogenic sediments from the shelf to the deep sea. Ten multi-cores from the Cascais Canyon and from the neighbour slopes (off Estremadura and Sines) were dated by 21Opb methodologies and analyzed for texture, major and trace metals to evaluate the role of submarine canyons in the transport of anthropogenic metals to the abyssal plains. Higher accumulation mass rates were ...

  3. A method of gastric conduit elevation via the posterior mediastinal pathway in thoracoscopic subtotal esophagectomy

    OpenAIRE

    Hirahara Noriyuki; Yamamoto Tetsu; Tanaka Tsuneo

    2012-01-01

    Abstract Background Despite efforts to improve surgical techniques, serious complications still sometimes occur. Use of a physiological posterior mediastinal pathway has increased given advances such as automated anastomotic devices and a reduction in the incidence of anastomotic sufficiency. Until now the gastric conduit created has been protected by an echo probe cover and, sown to the ventral side of polyester tape placed through the abdomen to the neck, and then blindly elevated to the ne...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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.)

  12. 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.

  13. 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

  14. 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.

  15. Non-Newtonian rheology of bubble-bearing magmas: effects on conduit dynamics.

    Science.gov (United States)

    Colucci, Simone; Papale, Paolo; Montagna, Chiara

    2015-04-01

    Non-Newtonian rheology typically arises in magmas from the presence of a dispersed phase. In particular bubbles can reduce or increase the relative viscosity, depending on size and strain regime (i.e., capillary number), for example large bubbles, as well as low strain, reduce the apparent viscosity. In a Non-Newtonian regime it is not possible to define a strain-rate-independent viscosity and the velocity profile is complex. In this work we extended the 1D, steady, isothermal, multiphase non-homogeneous magma ascent model of Papale (2001) to 1.5D to include the Non-Newtonian effect of a bubble-bearing magma. The model has been tested with a basaltic test case. In this way we were able to calculate depth-dependent Non-newtonian velocity profiles across the conduit radius along with shear strain-rate and viscosity distributions. Moreover, the model could quantify the effects of the Non-Newtonian rheology on conduit flow dynamics, in terms of flow variables (e.g. velocity, pressure). P. Papale (2001). Dynamics of magma flow in volcanic conduits with variable fragmentation efficiency and nonequilibrium pumice degassing. JGR, 106, 11043-11065.

  16. 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...

  17. 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...

  18. 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

  19. 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

  20. 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.

  1. Warm Vapor Atom Interferometer

    Science.gov (United States)

    Biedermann, Grant; Wheeler, David; Jau, Yuan-Yu; McGuinness, Hayden

    2014-05-01

    We present a light pulse atom interferometer using room temperature rubidium vapor. Doppler sensitive stimulated Raman transitions forming the atom optical elements inherently select a cold velocity group for the interferometer. The interferometer is configured to be sensitive to accelerations. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  2. 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

  3. 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.

  4. 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.

  5. Mechanical properties and permeability of porous chitosan-poly(p-dioxanone)/silk fibroin conduits used for peripheral nerve repair.

    Science.gov (United States)

    Wu, Hua; Zhang, Jun; Luo, Ying; Wan, Ying; Sun, Shaofa

    2015-10-01

    Some poly(p-dioxanone) (PDO) homopolymers were first synthesized and the selected PDO was conjugated onto chitosan using a group-protecting method to produce chitosan-poly(p-dioxanone) (CH-PDO) copolymers with various PDO percentages changing from around 30 to 60wt%. The CH-PDO with the PDO content of around 42wt% was used to blend with prescribed amounts of silk fibroin (SF) to build porous single-lumen conduits that are intended to be used for long-gap peripheral nerve repair. Some genipin-crosslinked CH-PDO/SF conduits were endowed with an average porosity of around 60% in their porous wall, and with changed pore-sizes varying from around 10 to ca. 70?m using optimized processing conditions. After being degraded in a PBS medium containing a certain amount of lysozyme for various periods up to 8 weeks, some optimal CH-PDO/SF conduits were able to retain their compressive load and deformation recovery at around 59N/m and 73% in wet state, respectively. In addition, the achieved CH-PDO/SF conduits allowed the permeation of nutritional molecules with various molecular weights while showing a certain ability to prevent cells from infiltrating through the conduit wall. Cell culture confirmed that the optimized CH-PDO/SF conduits were able well supported the growth of rat glioma C6 cells. These results suggest that presently developed CH-PDO/SF conduits have promising potential for long-gap peripheral nerve repair. PMID:26143352

  6. NRC Information No. 90-23: Improper installation of Patel conduit seals

    International Nuclear Information System (INIS)

    On November 6, 1989, the staff at the H.B. Robinson plant notified the NRC that they had discovered that some of the conduit seal grommets used to seal insulated wire conductors entering environmentally qualified instrument housings were oversized for the application. The seals are used to prevent moisture from entering safety-related electrical components following loss-of-coolant accidents. The problem was attributed to inadequate installation instructions that were used when the seals were installed in 1986 and 1987. These instructions listed the grommets by wire gauge size and gave maximum wire insulation diameters for each wire size. In accordance with these instructions, the seals were selected based on wire gauge alone. However, since the insulation thickness for a given wire gauge the correct grommet size would have been the minimum wire insulation diameter for which a particular grommet will achieve an effective seal. The selection of grommet size based only on wire gauge size resulted in the installation of some grommets that were too large to provide an effective seal. As a result, some of the seals failed pressure tests that were designed to simulate post-LOCA pressures. During the investigation of the grommet leakage problem, the Robinson staff also checked the torque on the conduit seal union nuts that are used to compress the seals. EGS Corporation recommends that the union nuts be torqued to 50 ft-lb. On approximately half of the 90 seals inspected, the union nut moved about 1/4 inch when this torque was applied. EGS Corporation reports that 1/4 inch of movement does not necessarily indicate a degraded seal but recommends that the correct torque be verified on a representative sample of installed conduit seals

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. Systems and methods for coating conduit interior surfaces utilizing a thermal spray gun with extension arm

    Science.gov (United States)

    Moore, Karen A.; Zatorski, Raymond A.

    2005-07-12

    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.

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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.

  18. Collapsing criteria for vapor film around solid spheres as a fundamental stage leading to vapor explosion

    Energy Technology Data Exchange (ETDEWEB)

    Freud, Roy [Nuclear Research Center - Negev, Beer-Sheva (Israel)], E-mail: freud@bgu.ac.il; Harari, Ronen [Nuclear Research Center - Negev, Beer-Sheva (Israel); Sher, Eran [Pearlstone Center for Aeronautical Studies, Department of Mechanical Engineering, Ben-Gurion University, Beer-Sheva (Israel)

    2009-04-15

    Following a partial fuel-melting accident, a Fuel-Coolant Interaction (FCI) can result with the fragmentation of the melt into tiny droplets. A vapor film is then formed between the melt fragments and the coolant, while preventing a contact between them. Triggering, propagation and expansion typically follow the premixing stage. In the triggering stage, vapor film collapse around one or several of the fragments occurs. This collapse can be the result of fragments cooling, a sort of mechanical force, or by any other means. When the vapor film collapses and the coolant re-establishes contact with the dry surface of the hot melt, it may lead to a very rapid and rather violent boiling. In the propagation stage the shock wave front leads to stripping of the films surrounding adjacent droplets which enhance the fragmentation and the process escalates. During this process a large quantity of liquid vaporizes and its expansion can result in destructive mechanical damage to the surrounding structures. This multiphase thermal detonation in which high pressure shock wave is formed is regarded as 'vapor explosion'. The film boiling and its possible collapse is a fundamental stage leading to vapor explosion. If the interaction of the melt and the coolant does not result in a film boiling, no explosion occurs. Many studies have been devoted to determine the minimum temperature and heat flux that is required to maintain a film boiling. The present experimental study examines the minimum temperature that is required to maintain a film boiling around metal spheres immersed into a liquid (subcooled distilled water) reservoir. In order to simulate fuel fragments that are small in dimension and has mirror-like surface, small spheres coated with anti-oxidation layer were used. The heat flux from the spheres was calculated from the sphere's temperature profiles and the sphere's properties. The vapor film collapse was associated with a sharp rise of the heat flux during the cooling process-from values typical for film boiling to much higher values typical for nucleate boiling. Correlations for the minimum temperature and the minimum heat flux necessary to maintain film boiling were established in terms of the subcooling level, the size of the spheres and their material. The minimum temperature to maintain film boiling was used as the principle criteria for the occurrence of vapor explosion. Other criteria, for the intensity of the vapor film collapse was derived from the maximum heat flux following the vapor film collapse, and the audible sound (which is generated by the shock wave). It is assumed that a high intensity of the vapor film collapse will result in a more efficient propagation stage and enhancement of the vapor explosion.

  19. 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.

  20. Three-dimensional printed trileaflet valve conduits using biological hydrogels and human valve interstitial cells.

    Science.gov (United States)

    Duan, B; Kapetanovic, E; Hockaday, L A; Butcher, J T

    2014-05-01

    Tissue engineering has great potential to provide a functional de novo living valve replacement, capable of integration with host tissue and growth. Among various valve conduit fabrication techniques, three-dimensional (3-D) bioprinting enables deposition of cells and hydrogels into 3-D constructs with anatomical geometry and heterogeneous mechanical properties. Successful translation of this approach, however, is constrained by the dearth of printable and biocompatible hydrogel materials. Furthermore, it is not known how human valve cells respond to these printed environments. In this study, 3-D printable formulations of hybrid hydrogels are developed, based on methacrylated hyaluronic acid (Me-HA) and methacrylated gelatin (Me-Gel), and used to bioprint heart valve conduits containing encapsulated human aortic valvular interstitial cells (HAVIC). Increasing Me-Gel concentration resulted in lower stiffness and higher viscosity, facilitated cell spreading, and better maintained HAVIC fibroblastic phenotype. Bioprinting accuracy was dependent upon the relative concentrations of Me-Gel and Me-HA, but when optimized enabled the fabrication of a trileaflet valve shape accurate to the original design. HAVIC encapsulated within bioprinted heart valves maintained high viability, and remodeled the initial matrix by depositing collagen and glyosaminoglycans. These findings represent the first rational design of bioprinted trileaflet valve hydrogels that regulate encapsulated human VIC behavior. The use of anatomically accurate living valve scaffolds through bioprinting may accelerate understanding of physiological valve cell interactions and progress towards de novo living valve replacements. PMID:24334142

  1. 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

  2. Operação de Rastelli utilizando-se conduto valvulado de pericárdio bovino: experiência inicial / Rastelli operation with bovine pericardium valved conduit: early experience

    Scientific Electronic Library Online (English)

    Carlos R, Moraes; Jorge V, Rodrigues; Cláudio A, Gomes; Lorella, Marinucci; Cleuza Lapa, Santos; Tereza Cristina, Coelho; Ivan de Lima, Cavalcanti.

    1988-08-01

    Full Text Available O presente trabalho descreve a experiência inicial com a operação de Rastelli, utilizando-se um conduto valvulado de pericárdio bovino preservado em glutaraldeído. O enxerto consta de um conduto, que serve para reconstruir a via de saída do ventrículo direito e o tronco pulmonar, com uma válvula tri [...] cúspide suturada em seu interior sem anel de suporte, permitindo, assim, um mecanismo de fluxo unidirecional. De maio de 1986 a outubro de 1987, 5 crianças foram submetidas à operação de Rastelli empregando-se este tipo de conduto valvulado. Três eram do sexo feminino e 2, do masculino, variando a idade de 1 a 8 anos x 5). Três pacientes tinham transposição das grandes artérias, comunicação interventricular (CIV) e estenose subpulmonar. Uma criança era portadora de atresia pulmonar com CIV e de um shunt prévio tipo Waterston e, finalmente, a outra tinha um tronco arterial comum tipo II. Dois doentes faleceram de causas não relacionadas ao tipo de conduto valvulado utilizado. O conduto valvulado de pericárdio bovino preservado em glutaraldeído mostrou excelente flexibilidade, facilitando o manuseio cirúrgico e permitindo perfeita adaptabilidade dentro do saco pericárdico. A ausência de anel de suporte tem a vantagem de eliminar qualquer gradiente e de abolir o turbilhonamento do sangue - causas reconhecidas de calcificação. Abstract in english The present report describes the initial experience with the Rastelli operation utilizing a composite graft of glutaraldehyde preserved bovine pericardium. The graft is made up of a tube which serves to reconstruct the outflow tract of the right ventricle and the pulmonary artery, and an inner tricu [...] spid valve, without a supporting ring, which provides the tube with a one-way flow mechanism. From May, 1986 to October, 1987, five children were submitted to Rastelli operation utilizing this valved tube. Three were female and two male, ranging in age from 1 e to 8 years (mean 5 years). Three had transposition of the great arteries, VSD and subpulmonic stenosis, one had pulmonary atresia, VSD and a previous Waterston shunt, and one had a type II truncus arteriosus. Two patients died of causes unrelated to the type of the conduit used. The valved conduit of preserved bovine pericardium is easy to handle due to its excellent flexibility, allowing perfect adaptability inside the pericardial sac. The absence of a supporting ring abolish gradient across the conduit and turbulence which are recognized causes of calcification.

  3. 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 

  4. 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.

  5. 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

  6. Surface reaction of titanium beryllide with water vapor

    International Nuclear Information System (INIS)

    Beryllium is one of the candidate materials for the neutron multiplier in the tritium-breeding blanket. However, there are some problems related to the application of beryllium as a neutron multiplier, which include compatibility with structural materials, tritium inventory and reaction of beryllium with water vapor and oxygen in a LOCA accident. Titanium beryllides such as Be12Ti are known to have advantages over beryllium from the perspectives of higher melting point, lower chemical reactivity and lower swelling. Thus, these materials are promising alternatives of beryllium. The authors investigate here the reaction of titanium beryllides with water vapor at high temperatures, and it is found that Be12Ti is by far more tolerant to water vapor than beryllium. To clarify the high tolerance of Be12Ti to water vapor, the surface of Be12Ti used in the experiment was investigated by means of digital microscope, SEM, XRD and electron spectroscopy for chemical analysis (ESCA). These analyses suggest that some oxidized state of beryllium was formed on the surface of Be12Ti exposed to water vapor. In particular, the results of the ESCA analysis gave some clues to understanding the higher tolerance of Be12Ti to water vapor at high temperatures

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Water vapor diffusion membranes, 2

    Science.gov (United States)

    Holland, F. F.; Klein, E.; Smith, J. K.; Eyer, C.

    1976-01-01

    Transport mechanisms were investigated for the three different types of water vapor diffusion membranes. Membranes representing porous wetting and porous nonwetting structures as well as dense diffusive membrane structures were investigated for water permeation rate as a function of: (1) temperature, (2) solids composition in solution, and (3) such hydrodynamic parameters as sweep gas flow rate, solution flow rate and cell geometry. These properties were measured using nitrogen sweep gas to collect the effluent. In addition, the chemical stability to chromic acid-stabilized urine was measured for several of each type of membrane. A technology based on the mechanism of vapor transport was developed, whereby the vapor diffusion rates and relative susceptibility of membranes to fouling and failure could be projected for long-term vapor recovery trials using natural chromic acid-stabilized urine.

  13. 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.

  14. 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.

  15. 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

  16. 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...

  17. 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.

  18. 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

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. 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...

  4. 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.

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

    Science.gov (United States)

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

    2013-12-01

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

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

    Directory of Open Access Journals (Sweden)

    G. G. J. Ernst

    2005-06-01

    Full Text Available 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 transfer below the Earth surface. Other models simulate atmospheric dispersal of the erupted gas-particle mixture, focusing on rapid processes occurring in the jet, the lower convective regions, and pyroclastic density currents. The ascending eruption column and intrusive gravity current generated by it, as well as sedimentation and ash dispersal from those flows in the immediate environment of the volcano are examined with modular and generic models. These apply simplifications to the equations describing the system depending on the specific focus of scrutiny. The atmospheric dispersion of volcanic clouds is simulated by ash tracking models. These are inadequate for the first hours of spreading in many cases but focus on long-range prediction of ash location to prevent hazardous aircraft - ash encounters. The climate impact is investigated with global models. All processes and effects of explosive eruptions cannot be simulated by a single model, due to the complexity and hugely contrasting spatial and temporal scales involved. There is now the opportunity to establish a closer integration between different models and to develop the first comprehensive description of explosive eruptions and of their effects on the ground, in the atmosphere, and on the global climate.

  7. 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

  8. Fast evolving conduits in clay-bonded sandstone: Characterization, erosion processes and significance for the origin of sandstone landforms.

    Czech Academy of Sciences Publication Activity Database

    Bruthans, J.; Svetlik, D.; Soukup, J.; Schweigstillová, Jana; Válek, Jan; Sedlá?ková, M.; Mayo, A.L.

    2012-01-01

    Ro?. 177, December (2012), s. 178-193. ISSN 0169-555X R&D Projects: GA AV ?R IAA300130806 Institutional support: RVO:67985891 ; RVO:68378297 Keywords : sandstone * erosion * piping * tensile strength * conduit * landform Subject RIV: DA - Hydrology ; Limnology Impact factor: 2.552, year: 2012

  9. 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.

  10. 75 FR 44982 - Arkansas Valley Conduit (AVC) and Long-Term Excess Capacity Master Contract, Fryingpan-Arkansas...

    Science.gov (United States)

    2010-07-30

    ... Bureau of Reclamation Arkansas Valley Conduit (AVC) and Long-Term Excess Capacity Master Contract... (Reclamation) proposes to prepare a draft EIS that analyzes effects associated with construction of the AVC, a..., please call no later than one week before the public meeting of interest. Background Information The...

  11. Ileal conduit without cystectomy may be an appropriate option in the treatment of intractable bladder pain syndrome/interstitial cystitis

    DEFF Research Database (Denmark)

    Norus, Thomas; Fode, Mikkel

    2014-01-01

    Abstract Objective. The aim of this study was to report the outcomes of urinary diversion for bladder pain syndrome/interstitial cystitis (BPS/IC) at a large university hospital over a period of more than 10 years. Material and methods. Chart reviews were performed for BPS/IC patients who had undergone ileal conduit with or without cystectomy. Questionnaires on quality of life, BPS/IC symptoms and pain were mailed to patients. Outcomes in the cystectomy and the non-cystectomy groups were compared with Fisher's exact test. Results. Ileal conduit without cystectomy was performed in 20 patients. Two underwent a subsequent cystectomy owing to persistent symptoms. Three patients underwent ileal conduit with concomitant primary cystectomy. Nineteen patients were alive at the time of the study and 15 returned the questionnaires. Twelve responders had been treated with ileal conduit and three had undergone primary cystectomy. The quality of life in both the cystectomy and the non-cystectomy groups was comparable withthat in the general population. Seven patients in the non-cystectomy group were free of specific BPS/IC symptoms. The remaining five patients had minimal symptoms. Two cystectomy patients were free of symptoms, while one still suffered from severe symptoms. Eleven patients reported having no pain while four patients had visual analogue scale (VAS) scores between 2 and 9.5. Three patients experiencing pain belonged to the non-cystectomy group. There was no difference between the cystectomy group and the non-cystectomy group with regard to the proportion of patients who were symptom free. Conclusion. Ileal conduit without cystectomy may be an appropriate option when performing urinary diversion in BPS/IC patients.

  12. 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

  13. 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.

  14. Fabrication of bioactive conduits containing the fibroblast growth factor 1 and neural stem cells for peripheral nerve regeneration across a 15 mm critical gap

    International Nuclear Information System (INIS)

    Nerve conduits are often used in combination with bioactive molecules and stem cells to enhance peripheral nerve regeneration. In this study, the acidic fibroblast growth factor 1 (FGF1) was immobilized onto the microporous/micropatterned poly (D, L-lactic acid) (PLA) nerve conduits after open air plasma treatment. PLA substrates grafted with chitosan in the presence of a small amount of gold nanoparticles (nano Au) showed a protective effect on the activity of the immobilized FGF1 in vitro. Different conduits were tested for their ability to bridge a 15 mm critical gap defect in a rat sciatic nerve injury model. Axon regeneration and functional recovery were evaluated by histology, walking track analysis and electrophysiology. Among different conduits, PLA conduits grafted with chitosan–nano Au and the FGF1 after plasma activation had the greatest regeneration capacity and functional recovery in the experimental animals. When the above conduit was seeded with aligned neural stem cells, the efficacy was further enhanced and it approached that of the autograft group. This work suggested that microporous/micropatterned nerve conduits containing bioactive growth factors may be successfully fabricated by micropatterning techniques, open plasma activation, and immobilization, which, combined with aligned stem cells, may synergistically contribute to the regeneration of the severely damaged peripheral nerve. (paper)

  15. 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

  16. 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.

  17. 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

  18. Fault textures in volcanic conduits: evidence for seismic trigger mechanisms during silicic eruptions

    Science.gov (United States)

    Tuffen, Hugh; Dingwell, Don

    2005-04-01

    It is proposed that fault textures in two dissected rhyolitic conduits in Iceland preserve evidence for shallow seismogenic faulting within rising magma during the emplacement of highly viscous lava flows. Detailed field and petrographic analysis of such textures may shed light on the origin of long-period and hybrid volcanic earthquakes at active volcanoes. There is evidence at each conduit investigated for multiple seismogenic cycles, each of which involved four distinct evolutionary phases. In phase 1, shear fracture of unrelaxed magma was triggered by shear stress accumulation during viscous flow, forming the angular fracture networks that initiated faulting cycles. Transient pressure gradients were generated as the fractures opened, which led to fluidisation and clastic deposition of fine-grained particles that were derived from the fracture walls by abrasion. Fracture networks then progressively coalesced and rotated during subsequent slip (phase 2), developing into cataclasite zones with evidence for multiple localised slip events, fluidisation and grain size reduction. Phase 2 textures closely resemble those formed on seismogenic tectonic faults characterised by friction-controlled stick-slip behaviour. Increasing cohesion of cataclasites then led to aseismic, distributed ductile deformation (phase 3) and generated deformed cataclasite zones, which are enriched in metallic oxide microlites and resemble glassy pseudotachylite. Continued annealing and deformation eventually erased all structures in the cataclasite and formed microlite-rich flow bands in obsidian (phase 4). Overall, the mixed brittle-ductile textures formed in the magma appear similar to those formed in lower crustal rocks close to the brittle-ductile transition, with the rheological response mediated by strain-rate variations and frictional heating. Fault processes in highly viscous magma are compared with those elsewhere in the crust, and this comparison is used to appraise existing models of volcano seismic activity. Based on the textures observed, it is suggested that patterns of long-period and hybrid earthquakes at silicic lava domes reflect friction-controlled stick-slip movement and eventual healing of fault zones in magma, which are an accelerated and smaller-scale analogue of tectonic faults.

  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

    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.

  2. 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.

  3. System for and method of controlling fuel flow to a heating device

    Energy Technology Data Exchange (ETDEWEB)

    Nystrom, T.L.

    1991-07-23

    This patent describes a fuel flow control system for a heating device. It comprises vertically extending fuel vaporization means for vaporizing liquid fuel into a fuel vapor for use in a combustion chamber of the heating device; means for applying heat externally to the vertically extending fuel vaporization means and converting the liquid fuel in the vaporization means to the fuel vapor from an upper surface of the liquid fuel; chamber means for holding a supply of the liquid fuel; conduit means for connecting the chamber means to a lower portion of the vertically extending liquid fuel vaporization means so that the liquid fuel free-flows through the conduit means to the vaporization means without any significant obstruction or metering; and means for establishing an upper surface level of the liquid fuel in the chamber means and a corresponding liquid fuel hydraulic head in the chamber means.

  4. 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

  5. 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

  6. 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.)

  7. 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.

  8. 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.)

  9. 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.

  10. 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.

  11. 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)

  12. 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)

  13. 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

  14. Bacteria ascend to liver from the bilioenteric conduit after choledochojejunostomy in the cholestatic rat.

    Science.gov (United States)

    Hsieh, C S; Huang, L-T; Huang, C C; Wu, J J; Chuang, J H

    2003-12-01

    The high incidence of postoperative cholangitis in children with clinical restoration of bile flow after Roux-Y choledochojejunostomy (RYCJ) assumed the concept of a direct ascending cholangitis caused by pathogens in the intestine, into the intrahepatic bile duct via the porta hepatis. It is also well known that jaundiced animals (patients) are more susceptible to infections of the bile ducts following the procedure of bilioenteric anastomosis. An animal experiment was conducted to compare quantitative bacterial cultures of the choledochojejunostomy area and the liver 24 hours after Escherichia coli (ATCC 25922) or sterile normal saline was injected into the bilioenteric conduit (BEC), following RYCJ in rats with or without the proceeding bile duct ligation. A significant increase of E. coli of the same strain (ATCC 25922), that we injected into the BEC, was proved with pulse-field gel electrophoresis (PFGE) and shown in the liver of the jaundiced rats receiving E. coli (ATCC 25922), compared to that in the nonjaundiced rats with normal saline treatment. It is concluded that bacteria often ascend early to the liver from the BEC following RYCJ. This ascending cholangitis model might be produced for further studies. PMID:14564465

  15. 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.

  16. 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

  17. 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

  18. 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.

  19. 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.

  20. 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)

  1. 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.

  2. 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.

  3. 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.

  4. 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...

  5. The interior of a volcanic summit: TerraSAR-X interferometry reveals complex conduit system at Volcán de Colima, Mexico

    Science.gov (United States)

    Salzer, Jacqueline T.; Nikkhoo, Mehdi; Walter, Thomas R.; Reyes-Dávila, Gabriel; Bretón, Mauricio; Arambula-Mendoza, Raul

    2014-05-01

    The dimensions and shape of the volcanic conduit is one of the main parameters controlling the dynamics and style volcanic eruptions and their precursors, but also one of the main unknowns. Different types of pre-eruptive signals originate from this region, such as changes in the gas composition, earthquakes, tremors and long periodic seismicity, as well as deformation on different scales, all of which strictly depend on the source geometry. However, vulnerability of near-summit stations during explosive eruptions leads to a sparse spatial resolution and hence poor a knowledge of the shallow source process and its parameters. Such incomplete observations also increase the difficulty of identifying episodes of unrest that will lead to eruption. At Volcán de Colima, Mexico, the plumbing of the shallow conduit system caused detectable and characteristic volcano deformation during the days prior to the renewal of the volcanic activity in 2013, which was initiated by an explosion. Here we present a model of the shallow conduit system at Colima, based on pre-explosive summit deformation detected in high resolution satellite radar and camera observations. The radar data are interferometrically processed to provide displacement maps up to 7 hours before the explosion, and are synthetically well reproduced using a boundary element method. This allows constraining a complex, possibly curved ascent path, with at least two hydraulically connected pressurized regions at shallow levels beneath the dome. The locations of the sources coincide with the later path of magma ascent. Our results highlight the geometrical complexity of the shallow conduit system at Colima, which can condionally become detectable when being plumbed prior to explosive eruptions. The small temporal and spatial extent of the deformation signal may explain why many volcano eruptions occur without precursory deformation activity.

  6. 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...

  7. 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...

  8. Peripheral Nerve Repair in Rats Using Composite Hydrogel-Filled Aligned Nanofiber Conduits with Incorporated Nerve Growth Factor

    OpenAIRE

    Jin, Jenny; Limburg, Sonja; Joshi, Sunil K.; Landman, Rebeccah; Park, Michelle; Zhang, Qia; Kim, Hubert T.; Kuo, Alfred C.

    2013-01-01

    Repair of peripheral nerve defects with current synthetic, tubular nerve conduits generally shows inferior recovery when compared with using nerve autografts, the current gold standard. We tested the ability of composite collagen and hyaluronan hydrogels, with and without the nerve growth factor (NGF), to stimulate neurite extension on a promising aligned, nanofiber poly-L-lactide-co-caprolactone (PLCL) scaffold. In vitro, the hydrogels significantly increased neurite extension from dorsal ro...

  9. 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...

  10. 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...

  11. 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.

  12. Efektivitas Membran Amnion Liofilisasi (Handmade Tubular sebagai Nerve Conduit pada Perbaikan Cedera Saraf Perifer Tikus dengan Gap 5 mm

    Directory of Open Access Journals (Sweden)

    R. Dadan G. Gandadikusumah

    2013-09-01

    Full Text Available Peripheral nerve injury with 5–30 mm gap which is caused by direct injury cases (87% or iatrogenic (12% become a special concern because it could cause a serious disability in the future. Therefore, we need many kinds of nerve repair methods without adding morbidity to the patient. One of the methods is entubulation method, by using natural or synthetic material. This was an animal experimental research by using simple random design in Departement Pharmachology Laboratory, Faculty of Medicine, Universitas Padjadjaran Bandung in May 2012. The samples were used 14 Wistar rats, divided into 2 groups. After creating gap on sciatic nerve, nerve conduit was installed on case group by using handmade tubular lyophilized amnion membrane. Nerve conduit was not installed in control group. After 21 days observation, conduction test and histopathology examination were done. Data were analyzed by using non-parametric statistical analysis sign test. All animals survived without any serious surgical complication. Result showed a significant difference between groups; the conduction test=0.016 (p<0.05, nerve growth to distal gap=0.063 (p<0.05, no radier direction of nerve growth=0.031 (p<0.05. Reaction of inflammation was minimum and there was no difference between two groups. In conclusion, handmade tubular lyophilized amnion membrane is effective as nerve conduit in repair of peripheral nerve injury with 5 mm gap.

  13. 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...

  14. 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...

  15. Health-related quality of life after radical cystectomy for bladder cancer in elderly patients with an ileal conduit, ureterocutaneostomy, or orthotopic urinary reservoir: a comparative questionnaire survey

    OpenAIRE

    Saika, Takashi; Arata,Ryoji; Tsushima, Tomoyasu; Nasu,Yasutomo; Suyama,Bunzo; Takeda, Katsuji; Ebara, Shin; Manabe,Daisuke; Kobayashi, Tomoko; Tanimoto,Ryuta; KUMON, HIROMI

    2007-01-01

    To compare the health-related quality of life of elderly patients after radical cystectomy for bladder cancer in urinary diversion groups: ileal conduit, ureterocutaneostomy, or orthotopic urinary reservoir. The 109 participating elderly patients aged 75 or older completed self-reporting questionnaires: the QLQ-C30, and on satisfaction with urinary diversion methods. Fifty-six patients had undergone constructions for ileal conduit diversion, 31 for ureterocutaneostomy, and 22 for orthotopic u...

  16. 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

  17. 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

  18. 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."

  19. 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

  20. 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.

  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. 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.

  3. 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.

  4. 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.

  5. 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)

  6. 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...

  7. 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.

  8. Continuous Gas Monitoring at the Unzen-Conduit-Drilling USDP-4

    Science.gov (United States)

    Tretner, A.; Zimmer, M.; Erzinger, J.; Saito, M.; Nakada, S.

    2005-12-01

    Unzen Volcano, located in the Shimabara Peninsula, Kyushu, southwest Japan, was selected as one of the Decade Volcanoes of the United Nation's Decade of Natural Disaster Reduction, since it represents an important type of dangerous volcano. The last eruption (1990-95) was monitored and investigated in detail, yielding several models on the eruption mechanism and magmatic processes. The focus of USDP4 - drilling was to further clarify the regional crustal structure and magma evolution processes that control the manner of growth and failure of the volcano. In addition, processes of conduit formation, magma degassing, and magma's interaction with groundwater was investigated. Petrological investigations show, that Unzen magma in the conduit contained 4-5 wt.% water, whereas water content of the lava at the surface is very small. It was modelled that the water was released at less that 1-2 km depth. In view of these constraints different physico-chemical models show a strong increase in magma viscosity and a pressure drop directly below the growing dome. The gas phase dissolved in the drill mud was analyzed continuously with an online gas monitoring system. The aim was to receive a gas profile along the whole borehole length in order to gain information on the volcano fluid circulation system, to detect possible pathways for gases produced during magma degassing, and to determine hydrothermal and/or volcanic fluid inflow horizons. N2, O2, CO2, CH4, H2S, H2, He and Ar analyses were achieved with a quadrupol mass spectrometer; 222Rn was measured with a Lucas cell alpha detecotor. This data and subsequent isotopic studies contribute in particular to the discussed models about the eruptive behavior of Mt. Unzen. However, limitations were given due to the extremely difficult drilling conditions. The highly fractured rock formation led to loss of drill mud circulation mainly in the shallow parts. First results show that significant fluid inflow horizons didn't occur above 500 m (drill string length). From that depth on, influences of invading fluids could be detected by real-time mud gas monitoring, but major changes in the mud gas composition occured only deeper than 1000 m. Cracks and fissures as well as rock formation changes were often correlated with increasing amounts of methane, radon and helium. Of major importance are fluid inflow zones with high 3He/4He ratios at 1555 m (7.3 RA), 1755.5 m (7.48 RA) and 1977.4 m (6.21 RA) depth, indicating a significant contribution of fluids with mantle signature. With respect to major questions related to the Unzens eruption mechanism, the detected major fluid and gas inflow horizons may be capable of supporting magmatic degassing processes. Also, a correlation between lithology and gas composition was observed. Increased H2S concentrations were detected while drilling in pyrite-rich rocks. Old lava dikes and their surroundings seem to comprise of a higher gas and fluid permeability than the other rock formations. A trend with depth, from a minor magmatic to a more magmatic influenced fluid regime was observed together with a change in type of hydrothermal alteration of the surrounding rock (chlorite-rich to pyrite-rich).

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. Control of flow through a vapor generator

    Science.gov (United States)

    Radcliff, Thomas D.

    2005-11-08

    In a Rankine cycle system wherein a vapor generator receives heat from exhaust gases, provision is made to avoid overheating of the refrigerant during ORC system shut down while at the same time preventing condensation of those gases within the vapor generator when its temperature drops below a threshold temperature by diverting the flow of hot gases to ambient and to thereby draw ambient air through the vapor generator in the process. In one embodiment, a bistable ejector is adjustable between one position, in which the hot gases flow through the vapor generator, to another position wherein the gases are diverted away from the vapor generator. Another embodiment provides for a fixed valve ejector with a bias towards discharging to ambient, but with a fan on the downstream side of said vapor generator for overcoming this bias.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. The QBO as potential amplifier and conduit to lower altitudes of solar cycle influence

    Directory of Open Access Journals (Sweden)

    H. G. Mayr

    2007-06-01

    Full Text Available In several papers, the solar cycle (SC effect in the lower atmosphere has been linked observationally to the Quasi-biennial Oscillation (QBO of the zonal circulation. Salby and Callaghan (2000 in particular analyzed the QBO wind measurements, covering more than 40 years, and discovered that they contain a large SC signature at 20 km. We present here the results from a study with our 3-D Numerical Spectral Model (NSM, which relies primarily on parameterized gravity waves (GW to describe the QBO. In our model, the period of the SC is taken to be 10 years, and the relative amplitude of radiative forcing varies exponentially with height, i.e., 0.2% at the surface, 2% at 50 km, and 20% at 100 km and above. Applying spectral analysis to identify the SC signature, the model generates a relatively large modulation of the QBO, which reproduces the observations qualitatively. The numerical results demonstrate that the QBO modulation, closely tracking the phase of the SC, is robust and persists at least for 70 years. The question is what causes the SC effect, and our analysis shows that four interlocking processes are involved: (1 In the mesosphere at around 60 km, the solar UV variations generate in the zonal winds a SC modulation of the 12-month annual oscillation, which is hemispherically symmetric and confined to equatorial latitudes like the QBO. (2 Although the amplitude of this equatorial annual oscillation (EAO is relatively small, its SC modulation is large and extends into the lower stratosphere under the influence of, and amplified by, wave forcing. (3 The amplitude modulations of both EAO and QBO are essentially in phase with the imposed SC heating for the entire time span of the model simulation. This indicates that, due to positive feedback in the wave mechanism, the EAO apparently provides the pathway and pacemaker for the SC modulation of the QBO. (4 Our analysis demonstrates that the SC modulations of the QBO and EAO are amplified by tapping the momentum from the upward propagating gravity waves. Influenced and amplified by wave processes, the QBO thus acts as conduit to transfer to lower altitudes the larger SC variations in the UV absorbed in the mesosphere. Our model produces in the temperature variations of the QBO and EAO measurable SC modulations at polar latitudes near the tropopause. The effects are apparently generated by the meridional circulation, and planetary waves presumably, which redistribute the energy from the equatorial region where the waves are very effective in amplifying the SC influence.

  3. 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.

  4. 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.

  5. 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.

  6. Seasonal Trends in Stratospheric Water Vapor as Derived from SAGE II Data

    Science.gov (United States)

    Roell, Marilee M.; Fu, Rong

    2008-01-01

    Published analysis of HALOE and Boulder balloon measurements of water vapor have shown conflicting trends in stratospheric water vapor for the periods of 1981 through 2005. Analysis of the SAGE II monthly mean water vapor data filtered for large aerosol events for time periods from 1985-1991, 1995-1999, and 2000-2005 have shown a globally decreasing water vapor trend at 17.5km. Seasonal analysis for these three time periods show a decreasing trend in water vapor at 17.5km for the winter and spring seasons. The summer and autumn seasonal analysis show a decreasing trend from 1985-2005, however, there is a increasing trend in water vapor at 17.5km for these seasons during 1995-2005. Latitude vs height seasonal analysis show a decreasing trend in the lower stratosphere between 20S - 20N for the autumn season, while at the latitudes of 30-50S and 30-50N there is an increasing trend in water vapor at heights up to 15km for that season. Comparison with regions of monsoon activity (Asian and North American) show that the Asian monsoon region had some effect on the lower stratospheric moistening in 1995-1999, however, for the time period of 2000-2005, there was no change in the global trend analysis due to either monsoon region. This may be due to the limitations of the SAGE II data from 2000-2005.

  7. Destilación de aceite usando vapor con propano

    OpenAIRE

    M.A. Ram\\u00EDrez-Garnica; O. Cazarez-Candia; D.D. Mamora

    2007-01-01

    Con el fin de mejorar la producción de aceites pesados, en trabajos previos se han realizado experimentos relacionados con la inyección de vapor y el uso de propano como aditivo, obteniéndose los siguientes resultados: (1) se acelera la producción, (2) se incrementa la inyectividad del vapor, y (3) la velocidad del frente de vapor es más grande. Estos resultados indican un mejoramiento de las propiedades del aceite, sin embargo, con dichos experimentos no es posible explicar el or...

  8. 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...

  9. 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...

  10. 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

  11. 33 CFR 154.828 - Vapor recovery and vapor destruction units.

    Science.gov (United States)

    2010-07-01

    ...POLLUTION FACILITIES TRANSFERRING OIL OR HAZARDOUS MATERIAL IN BULK Vapor Control Systems § 154...the quick-closing stop valves required by paragraph (b)(2) of this...operated cargo vapor shutoff valve required by § 154.810(a) of...

  12. Gravity sensitivity of a resistojet water vaporizer

    Science.gov (United States)

    Morren, W. Earl

    1993-06-01

    A laboratory model of a water vaporizer for resistojet applications was designed, fabricated, and steady and transient characteristics were measured. Vaporizer operation was not impacted by rotation about a horizontal axis normal to its own. The vaporizer was operated under low and high accelerations aboard a jet aircraft for periods up to 25 s at flow rates ranging from 159(10)(exp -6) to 230(10)(exp -6) kg/s. Slight changes in inlet and outlet pressures and some heat exchanger temperatures were observed during the low-gravity tests. However, the results of these tests indicated probable compatibility of the vaporizer design tested with a low-gravity environment.

  13. 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.

  14. Water vapor, whence comest thou.

    Science.gov (United States)

    Freeman, J. W., Jr.; Hills, H. K.; Vondrak, R. R.

    1972-01-01

    During a 14-hour period on Mar. 7, 1971, the Apollo 14 ALSEP suprathermal ion detector experiment (SIDE) observed an intense, prolonged series of bursts of 48.6-eV ions at the lunar surface. The SIDE mass analyzer showed the mass per unit charge of these ions to be characteristic of water vapor if singly ionized. The event was also observed by the SIDE total ion detectors (TIDs) at the Apollo 14 site and at Apollo 12 (located 183 km to the west). The TID data from SIDE 14 indicate that the energy spectrum was narrower than the 20-eV interval between energy channels. Ion spectra due to the LM exhaust gases are shown to be readily identified by the SIDE and are distinctly different in character from the spectra obtained on March 7. Detailed consideration of other possible sources of water, including the Apollo 14 CSM, leads to the conclusion that the water vapor did not come from a man-made source. Also, it is estimated that the event may have involved a quantity of water much greater than that which has been artificially introduced into the lunar environment. Consequently, it appears to be of lunar origin.

  15. Application of atmospheric CVD for internal surface coating of graphite conduit by silicon carbide

    Science.gov (United States)

    Rao, P. T.; Jain, U.; Mollick, P. K.; Agarwal, A.; Chakravartty, J. K.; Kumar, Sanjay

    2015-01-01

    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.

  16. 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.

  17. 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.

  18. 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...

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. 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.

  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. 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.

  7. Influence of mass flow rate on Turbulent Kinetic Energy (TKE) distribution in Cable-in-Conduit Conductors (CICCs) used for fusion grade magnets

    Energy Technology Data Exchange (ETDEWEB)

    Dondapati, Raja Sekhar, E-mail: drsekhar@ieee.org; Rao, V.V.

    2013-06-15

    Highlights: • Mechanism associated with turbulent flow in CICC is investigated using CFD. • Reynolds Number (Re) affects the TKE in central channel but not that in bundle channel. • The loss of TKE occurs at the interface between central and bundle channels. • The loss of TKE is also observed as the flow progresses past the spiral rib. • In the absence of external heat sources, loss of TKE leads to temperature rise of SHe. -- Abstract: Thermohydraulic analysis is beneficial to understand the complex flow behavior in dual channel cable-in-conduit conductors (CICC) used in Tokomaks such as International Thermonuclear Experimental Reactor (ITER). Such dual channel CICC contains an annular and a central channel separated by a spiral. The cable bundle channel of CICC can be assumed to be porous and the central channel a clear region for thermohydraulic analysis using Computational Fluid Dynamics (CFD). Flow through CICC is found to be turbulent and this turbulence is transported in the form of small eddies. These eddies may dissipate the energy in the form of heat while being transported and finally the smaller eddies may combine to form larger eddy or may die out. Such phenomenon can be well explained with the help of a parameter called Turbulent Kinetic Energy (TKE), which determines the energy possessed by the eddies in the turbulent flow. In the present work, a three dimensional model of dual channel CICC is developed in GAMBIT-2.1 and solved using a compatible solver FLUENT-6.3.26. The influence of mass flow rate on Turbulent Kinetic Energy (TKE), which is defined as the mean kinetic energy per unit mass associated with eddies in turbulent flow, is analyzed. The computational results of pressure drop and flow repartition are validated against relevant experimental published results.

  8. Influence of mass flow rate on Turbulent Kinetic Energy (TKE) distribution in Cable-in-Conduit Conductors (CICCs) used for fusion grade magnets

    International Nuclear Information System (INIS)

    Highlights: • Mechanism associated with turbulent flow in CICC is investigated using CFD. • Reynolds Number (Re) affects the TKE in central channel but not that in bundle channel. • The loss of TKE occurs at the interface between central and bundle channels. • The loss of TKE is also observed as the flow progresses past the spiral rib. • In the absence of external heat sources, loss of TKE leads to temperature rise of SHe. -- Abstract: Thermohydraulic analysis is beneficial to understand the complex flow behavior in dual channel cable-in-conduit conductors (CICC) used in Tokomaks such as International Thermonuclear Experimental Reactor (ITER). Such dual channel CICC contains an annular and a central channel separated by a spiral. The cable bundle channel of CICC can be assumed to be porous and the central channel a clear region for thermohydraulic analysis using Computational Fluid Dynamics (CFD). Flow through CICC is found to be turbulent and this turbulence is transported in the form of small eddies. These eddies may dissipate the energy in the form of heat while being transported and finally the smaller eddies may combine to form larger eddy or may die out. Such phenomenon can be well explained with the help of a parameter called Turbulent Kinetic Energy (TKE), which determines the energy possessed by the eddies in the turbulent flow. In the present work, a three dimensional model of dual channel CICC is developed in GAMBIT-2.1 and solved using a compatible solver FLUENT-6.3.26. The influence of mass flow rate on Turbulent Kinetic Energy (TKE), which is defined as the mean kinetic energy per unit mass associated with eddies in turbulent flow, is analyzed. The computational results of pressure drop and flow repartition are validated against relevant experimental published results

  9. Effects of vaporization on debris cloud dynamics

    International Nuclear Information System (INIS)

    Experimental techniques are discussed for studying the debris products produced by plane shock loading of specimens to final temperatures sufficient to cause vaporization. These techniques have been applied to a study of the shock-induced vaporization of cadmium. The expansion products produced by shock reflections from a free surface were studied by allowing the debris to stagnate against a time-resolved interferometer gauge that allowed measurement of the stagnation pressure history. The experimental results were modeled in one dimension with Eulerian and Lagrangian computer wave codes utilizing detailed equations of state for cadmium. These comparisons illustrate that vaporization of cadmium occurs under essentially equilibrium conditions and that good agreement with experimental results is obtained under the assumption of instantaneous vaporization. Another observation is that the vapor expansion appears to be a centered expansion wave with a density distribution differing from the computer calculation

  10. 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.

  11. 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.

  12. Safe and simple gastric conduit pull-through procedure through the posterior mediastinal route using echo probe cover in thoracoscopic subtotal esophagectomy.

    Science.gov (United States)

    Hirahara, Noriyuki; Matsubara, Takeshi; Hira, Eiji; Yamamoto, Tetsu; Kidani, Akihiko; Hyakudomi, Ryoji; Shimojo, Yoshihide; Tajima, Yoshitsugu

    2013-08-01

    A gastric conduit is commonly used to reconstruct the alimentary tract after esophagectomy. When the posterior mediastinum is applied to a reconstruction route, the gastric conduit created has been protected by an echo probe cover and, then blindly elevated to the neck. However, using this elevation method, the gastric conduit has the potential to catch on the vessels and nerves, posing a risk of major bleeding. We report a safe method of gastric conduit pull-through procedure to avoid unexpected technical complications. Two approximately 60-cm-long polyester tapes are prepared and ligated at both ends forming a loop. A 50-cm-long echo probe cover of 10 cm in diameter is prepared, and the closed end of the echo probe cover is cut to make an open-ended echo probe cover. A line parallel to the long axis of the echo probe cover is drawn across the echo probe cover with a sterile surgical marking pen. The looped polyester tape is inserted into the echo probe cover. The looped polyester tape and echo probe cover are ligated with 2-0 silk, approximately 5 cm in front of the knots on both sides. After dissection is carried out according to practice, the previously crafted polyester tape is inserted into the chest cavity. The echo probe cover is placed to connect the distal and proximal ends of the esophagus, and its torsion is corrected using the line marked with the pen and a crease, both of which are parallel to the long axis of the echo probe cover. One end of polyester tape is fixed to the distal esophageal stump by using the clips, with the opposite end fixed to the proximal esophageal stump. Either one of the 2 lengths of polyester tape is connected to the gastric conduit. By pulling up this length of polyester tape from the neck, the gastric conduit can pass through the echo probe cover and be elevated to the neck. PMID:23917601

  13. 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.

  14. 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.

  15. 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,...

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. Vapors-liquid phase separator. [infrared telescope heat sink

    Science.gov (United States)

    Frederking, T. H. K.; Brown, G. S.; Chuang, C.; Kamioka, Y.; Kim, Y. I.; Lee, J. M.; Yuan, S. W. K.

    1980-01-01

    The use of porous plugs, mostly with in the form of passive devices with constant area were considered as vapor-liquid phase separators for helium 2 storage vessels under reduced gravity. The incorporation of components with variable cross sectional area as a method of flow rate modification was also investigated. A particular device which uses a shutter-type system for area variation was designed and constructed. This system successfully permitted flor rate changes of up to plus or minus 60% from its mean value.

  2. CO2 DIAL measurements of water vapor

    Science.gov (United States)

    Grant, William B.; Margolis, Jack S.; Brothers, Alan M.; Tratt, David M.

    1987-01-01

    CO2 lidars have heretofore been used to measure water vapor concentrations primarily using the 10R(20) line at 10.247 microns, which has a strong overlap with a water vapor absorption line. This paper discusses the use of that line as well as other CO2 laser lines for which the absorption coefficients are weaker. The literature on measurement of water vapor absorption coefficients using CO2 lasers is reviewed, and the results from four laboratories are shown to be generally consistent with each other after they are normalized to the same partial pressure, temperature, and ethylene absorption coefficent for the 10P(14) CO2 laser line; however, the agreement with the Air Force Geophysics Laboratory's HITRAN and FASCOD 2 spectral data tapes is not good either for the water vapor absorption lines or for the water vapor continuum. Demonstration measurements of atmospheric water vapor have been conducted using the Mobile Atmospheric Pollutant Mapping System, a dual CO2 lidar system using heterodyne detection. Results are discussed for measurements using three sets of laser line pairs covering a wide range of water vapor partial pressures.

  3. Internalized Meaning Factualism

    DEFF Research Database (Denmark)

    Hohwy, Jakob

    2006-01-01

    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 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 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 factualism is unstable. The problems about the normativity of meaning can therefore not be sidestepped in this way.

  4. 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.

  5. 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)

  6. 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.

  7. 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

  8. 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...

  9. 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...

  10. 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.

  11. 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

  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. 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).

  14. 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.

  15. 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.

  16. 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)

  17. Analytical modeling of the subsurface volatile organic vapor concentration in vapor intrusion

    OpenAIRE

    Shen, Rui; Pennell, Kelly G.; Suuberg, Eric M.

    2013-01-01

    The inhalation of volatile and semi-volatile organic compounds that intrude from a subsurface contaminant source into indoor air has become the subject of health and safety concerns over the last twenty years. Building subslab and soil gas contaminant vapor concentration sampling have become integral parts of vapor intrusion field investigations. While numerical models can be of use in analyzing field data and in helping understand the subslab and soil gas vapor concentrations, they are not w...

  18. 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

  19. 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

  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. 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.

  2. 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)...

  3. 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...

  4. 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.

  5. 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.

  6. 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)

  7. 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.

  8. 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...

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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

  20. 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

  1. Liquid-vapor and liquid-liquid interfaces in Ising fluids: an integral equation approach.

    Science.gov (United States)

    Omelyan, I P; Folk, R; Mryglod, I M; Fenz, W

    2007-03-28

    The microscopic structure and thermodynamic properties of liquid-vapor and liquid-liquid interfaces in Ising fluids are studied using an integral equation approach. The calculations are performed in the absence and presence of an external magnetic field by solving the corresponding set of Lovett-Mou-Buff-Wertheim integrodifferential equations for the one-particle density distribution functions. The two-particle inhomogeneous direct correlation functions are consistently constructed by nonlinear interpolation between the bulk ones. The bulk correlation functions of the coexisting phases are obtained from the Ornstein-Zernike equations with a modified soft mean spherical approximation for the closure relation. As a result, the density and magnetization profiles at liquid-vapor and liquid-liquid interfaces as well as the surface tension and adsorption coefficients are evaluated in a wide temperature range including subcritical regions. The influence of an external magnetic field on the liquid-vapor interfaces is also considered. PMID:17411147

  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. Modeling of the vapor cycle of Laguna Verde with the PEPSE code to conditions of thermal power licensed at present (2027 MWt); Modelado del ciclo de vapor de Laguna Verde con el codigo PEPSE a condiciones de potencia termica actualmente licenciada (2027 MWt)

    Energy Technology Data Exchange (ETDEWEB)

    Castaneda G, M. A.; Maya G, F.; Medel C, J. E.; Cardenas J, J. B.; Cruz B, H. J.; Mercado V, J. J., E-mail: miguel.castaneda01@cfe.gob.mx [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verde, Carretera Cardel-Nautla Km 42.5, Veracruz (Mexico)

    2011-11-15

    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)

  4. 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.

  5. 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.).

  6. Intercomparison of Water Vapor Transport Datasets

    Science.gov (United States)

    Hilburn, K. A.; Wentz, F. J.

    2010-12-01

    In 2008, we publicly released the Passive Microwave Water Cycle (PMWC) dataset, which was developed as part of the NASA Energy and Water Cycle Study (NEWS). This dataset integrates passive microwave observations from a variety of different sensors on different satellites to provide a complete characterization of the atmospheric branch of the water cycle over the global oceans. The Version-1b dataset provides monthly average, 0.25-degree maps of water vapor transport zonal (u) and meridional (v) components, water vapor transport divergence (D), evaporation (E), precipitation (P), and column-integrated water vapor (WV) spanning 1987-2009. We are using MERRA - The Modern Era Retrospective-analysis for Research and Applications - to compare two satellite based water vapor transport datasets: our Version-1b PMWC dataset and the Version-3 Liu and Xie dataset (also a NEWS dataset). We are evaluating the integrated vapor flux from the ocean into the continents, including: South America, North America, Africa, Eurasia, Australia, and Antarctica. Our approach allows us to make connections between uncertainties in the transport and the uncertainty in the total integrated flux, which depends on the orientation of the coastline relative to the transport over the ocean. MERRA is also being used to quantify the magnitude of sampling uncertainties - where the satellite datasets differ in land/ocean designation or have missing data due to sea ice.

  7. 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.

  8. 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

  9. The generation and evolution of anisotropic gas-permeability during viscous deformation in conduit-filling ignimbrites

    Science.gov (United States)

    Kolzenburg, Stephan; Russell, Kelly

    2015-04-01

    Gas-permeability plays a governing role in the pre-explosive pressurization of volcanic edifices. Pressurization may only occur once the total volume flux of gases emitted by an underlying magmatic or hydrothermal source exceeds the flow capacity of the permeable pathways present in the edifice. We have measured the physical properties (strain, porosity, permeability and ultrasonic wave velocities) of breadcrust bombs recovered from the deposits of the 2350 B.P. eruption of Mt Meager, BC, Canada. These rocks represent a conduit-infilling pyroclastic breccia that underwent various degrees of welding and deformation and present a remarkable opportunity to constrain the nature and timescale of mechanical processes operating within explosive volcanic conduits during repose periods between eruptive cycles. Here we present data from permeability measurements along the directions of maximum and minimum shortening which help quantifying the effect of vesicle microstructure on permeability. Permeability is measured by applying a range of confining pressures (between 3.4 and 17.2 MPa) to each sample and imposing a constant head (of 0.2 to 3.5 MPa) across the sample. The permeability is then determined using a modified version of Darcy's law applicable to compressible fluids. These rocks display a profound directionality in the measured physical properties resulting from the deformation-induced fabric. For all samples the permeability across the elongation fabric is highly correlated to the sample porosity whereas along the elongation fabric there is little effect of porosity on permeability. At porosity values of about 20% the permeability seems to reach a minimum at 10-16 m2 and does not change significantly with further reduction of porosity. Further, the effect of confining pressure on the permeability of these samples appears to be more pronounced across the elongation fabric than along the elongation fabric. The deformation fabric has a significant effect on the gas-permeability of the deposit. Porosity, on the other hand, appears to play a secondary role. This, fabric dependent, anisotropic permeability evolution of fragmental deposits during welding directly affects the gas escape from, and transport through the deposit and, therewith, plays a key role in the gas-pressure distribution and evolution within the volcano.

  10. Poly aniline Nano fiber as Modified Cladding for Optical Fiber Sensor to Detect Acetone Vapor

    International Nuclear Information System (INIS)

    In this research, we used poly aniline nano fiber as modified cladding material for a fiber optic sensor system to detect the acetone vapor. The sensor was designed based on variation of evanescent field absorption on the core-modified cladding interface when exposed with varied acetone vapor. Poly aniline nano fiber synthesized by interfacial polymerization was coated onto the un-cladded core and acts as sensing element. Response of the fiber optic sensor was investigated by measuring the transmission light intensity via fiber optic sensor system while exposed with acetone vapor. Based on the sensor response curve, it is obtained a very fast response time of 30 s and recovery time of 10 s. The fiber optic sensor also exhibits a good reversibility and repeatability. Sensitivity of the sensor to variation of acetone vapor pressure was obtained 1.25 %/mmHg, that means the transmission intensity of the sensor changes 1.25 % for acetone vapor change of 1 mmHg. (author)

  11. A Method For Retrieving Water Vapor Columnar Content And Aerosol Optical Thickness

    Science.gov (United States)

    Bassani, C.; Cavalli, R. M.; Estellés, V.; Gómez-Amo, J. L.; Martínez-Lozano, J. A.; Pignatti, S.; Utrillas, M. P.

    2006-08-01

    The capability to monitor and predict the physical characteristics of the atmosphere has been largely improved last decades. Aerosol optical thickness (AOT) and precipitable water vapor amount (W) are crucial atmospheric parameters in the understanding of atmospheric dynamics, as well as for the atmospheric correction of optical remote sensing images to be employed for land and water management. The objective of this work has been to adopt a methodology for measuring the water vapor and aerosol optical thickness in the atmospheric column by means of a Fieldspec Pro FR spectroradiometer. These measurements will be later useful for improving accuracy and helping to interpret remote sensing data, not only in the SPARC 2004 field campaign but for other future field campaigns aimed at land management. The methodology is based on two well-known techniques of sun photometry: the inversion of sun direct irradiance for AOT and split window, for precipitable water vapor. The direct solar irradiance were acquired simultaneously to Cimel CE318 NE and Microtops II measurements, working collocated during the SPARC 2004 campaign held at Barrax (Spain) in 2004 July. The obtained measurements have been compared to simultaneous retrievals from these collocated sun photometers. The results so far obtained showed the feasibility of this instrument to be employed for columnar water vapor and aerosol optical thickness retrieval. For water vapor, the deviation were found to be well within the estimated Cimel and Microtops uncertainty, stated as 10%.

  12. Attenuation of concentration fluctuations of water vapor and other trace gases in turbulent tube flow

    Directory of Open Access Journals (Sweden)

    W. J. Massman

    2008-10-01

    Full Text Available Recent studies with closed-path eddy covariance (EC systems have indicated that the attenuation of fluctuations of water vapor concentration is dependent upon ambient relative humidity, presumably due to sorption/desorption of water molecules at the interior surface of the tube. Previous studies of EC-related tube attenuation effects have either not considered this issue at all or have only examined it superficially. Nonetheless, the attenuation of water vapor fluctuations is clearly much greater than might be expected from a passive tracer in turbulent tube flow. This study reexamines the turbulent tube flow issue for both passive and sorbing tracers with the intent of developing a physically-based semi-empirical model that describes the attenuation associated with water vapor fluctuations. Toward this end, we develop a new model of tube flow dynamics (radial profiles of the turbulent diffusivity and tube airstream velocity. We compare our new passive-tracer formulation with previous formulations in a systematic and unified way in order to assess how sensitive the passive-tracer results depend on fundamental modeling assumptions. We extend the passive tracer model to the vapor sorption/desorption case by formulating the model's wall boundary condition in terms of a physically-based semi-empirical model of the sorption/desorption vapor fluxes. Finally we synthesize all modeling and observational results into a single analytical expression that captures the effects of the mean ambient humidity and tube flow (Reynolds number on tube attenuation.

  13. 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...

  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. 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.

  16. 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.

  17. 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.

  18. 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

  19. Outcome of Transurethral Plasmakinetic Vaporization for Benign Prostatic Hyperplasia

    Directory of Open Access Journals (Sweden)

    Magdy El-Tabey

    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 International 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 <0.01, and mean prostate volume from 72.8±10.3 mL to 22.7±6.1 mL (P value <0.01. Also, there was a statistically significant increase in the mean Q max. from 8.7±2.4 mL/s to 19.5±3.5 mL/s (P value <0.01. Conclusion PKVP is an effective and safe treatment option in the management of symptomatic BPH.

  20. Drag Reduction by Leidenfrost Vapor Layers

    KAUST Repository

    Vakarelski, Ivan Uriev

    2011-05-23

    We demonstrate and quantify a highly effective drag reduction technique that exploits the Leidenfrost effect to create a continuous and robust lubricating vapor layer on the surface of a heated solid sphere moving in a liquid. Using high-speed video, we show that such vapor layers can reduce the hydrodynamic drag by over 85%. These results appear to approach the ultimate limit of drag reduction possible by different methods based on gas-layer lubrication and can stimulate the development of related energy saving technologies.

  1. Water vapor release from biofuel combustion

    OpenAIRE

    R.S. Parmar; Welling, M.; Andreae, M.O.; Helas, G.

    2008-01-01

    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 ...

  2. Two-stage multi-Gaussian fitting of conduit artery photoplethysmography waveform during induced unilateral hemodynamic events

    Science.gov (United States)

    Grabovskis, Andris; Marcinkevics, Zbignevs; Rubins, Uldis; Aivars, Juris Imants

    2015-03-01

    Photoplethysmography (PPG) is an optical technique with high diagnostic potential, yet clinical applications remain underdeveloped. Standardization of signal recording and quantification of waveform are essential prerequisites for broader clinical use. The aim of this study was to utilize a two-stage multi-Gaussian fitting technique in order to examine the parameters of conduit artery PPG waveform recorded during increasing the unilateral regional vascular resistance (RVR). This study was conducted on 14 young and healthy volunteers; various external compressions (ECs) were performed by inflating a tight cuff at 0, 40, 80, and 200 mmHg, while registering femoral PPG (wavelength 880 nm), diameter, blood flow linear velocity (vascular ultrasound), and the arterial pressure (Finapres) during the states of the baseline, partial, and total arterial occlusion, and resultant reactive hyperemia. An increase of the EC elevated the arterial stiffness (AS) and the unilateral distal RVR, and caused a shift of the fitted multi-Gaussian parameters: a decreased delay between reflected and traverse wave components and an increased ratio of their amplitudes. It was concluded that two-stage multi-Gaussian waveform quantification demonstrates an approach potentially extending the use of arterial site PPG in the assessment of diagnostically useful markers e.g., the RVR and the AS.

  3. Cable-in-conduit conductors: lessons from the recent past for future developments with low and high temperature superconductors

    Science.gov (United States)

    Muzzi, L.; De Marzi, G.; Di Zenobio, A.; della Corte, A.

    2015-05-01

    We review progress in the design of high field superconducting cable-in-conduit conductors (CICCs) for fusion applications, with special attention to the results of recent key experiments, leading to the state-of-the-art CICC technology: the ITER Toroidal Field and Central Solenoid programs, the EFDA Dipole conductor development program, the NHFML Hybrid Magnet project, the EU-TF Alt conductor demonstration, and the CRPP React & Wind flat cable test. For these projects, the main CICC design driver was the mitigation of Nb3Sn conductor performance degradation with electro-magnetic loading cycles. This was achieved by proper choice of cable layout and of conductor geometry, depending on the specific operating conditions and project requirements. In all cases, the necessity to limit cable movements inside the conductor jacket was identified to be of crucial importance. The main aspects of CICC manufacture are also discussed here, at least for what is the experience gained by the authors in both CICC jacketing and cabling processes. Finally, the state of the art of high-temperature superconducting (HTS) cables is discussed: at present, this technology is still in its infancy, but it is highly likely that major technological improvements could eventually lead to a widespread use of HTS CICCs.

  4. Helium flow and temperatures in a heated sample of a final ITER TF cable-in-conduit conductor

    Energy Technology Data Exchange (ETDEWEB)

    Herzog, Robert; Calvi, Marco [EPFL-CRPP, Fusion Technology, 5232 Villigen PSI (Switzerland); Lewandowska, Monika [West Pomeranian University of Technology, Szczecin (Poland); Bessette, Denis, E-mail: Robert.Herzog@psi.c [ITER International Organization, 13108 St Paul lez Durance (France)

    2010-06-01

    The quest for a detailed understanding of the thermo-hydraulic behaviour of the helium flow in the dual-channel cable-in-conduit conductor (CICC) for the ITER toroidal-field coils led to a series of experiments in the SULTAN test facility on a dedicated sample made according to the final conductor design. With helium flowing through the conductor as expected during ITER operation, the sample was heated by eddy-current losses induced in the strands by an applied AC magnetic field as well as by foil heaters mounted on the outside of the conductor jacket. Temperature sensors mounted on the jacket surface, in the central channel and at different radii in the sub-cable region showed the longitudinal as well as radial temperature distribution at different mass flow rates and heat loads. Spot heaters in the bundle and the central channel created small heated helium regions, which were detected downstream by a series of temperature sensors. With a time-of-flight method the helium velocity could thus be determined independently of any flow model. The temperature and velocity distributions in bundle and central channel under different mass-flow and heat load conditions thus led to a detailed picture of the helium flow in the final ITER TF CICCs.

  5. Helium flow and temperatures in a heated sample of a final ITER TF cable-in-conduit conductor

    International Nuclear Information System (INIS)

    The quest for a detailed understanding of the thermo-hydraulic behaviour of the helium flow in the dual-channel cable-in-conduit conductor (CICC) for the ITER toroidal-field coils led to a series of experiments in the SULTAN test facility on a dedicated sample made according to the final conductor design. With helium flowing through the conductor as expected during ITER operation, the sample was heated by eddy-current losses induced in the strands by an applied AC magnetic field as well as by foil heaters mounted on the outside of the conductor jacket. Temperature sensors mounted on the jacket surface, in the central channel and at different radii in the sub-cable region showed the longitudinal as well as radial temperature distribution at different mass flow rates and heat loads. Spot heaters in the bundle and the central channel created small heated helium regions, which were detected downstream by a series of temperature sensors. With a time-of-flight method the helium velocity could thus be determined independently of any flow model. The temperature and velocity distributions in bundle and central channel under different mass-flow and heat load conditions thus led to a detailed picture of the helium flow in the final ITER TF CICCs.

  6. Differences in conduit and buffering function among arteries, venous grafts and synthetic prosthesis: Implicances in the development of intimal hyperplasia

    Scientific Electronic Library Online (English)

    D., Bia; E. I., Cabrera Fischer; Y., Zócalo; W., Barmak; F., Pessana; R., Armentano.

    2006-01-01

    Full Text Available Usually vascular surgeons consider the use of vein grafts as the materials of first choice for bypass or reconstruction of small arteries, while synthetic prosthesis (i.e. polytetrafluoroethylene, ePTFE) plays a secondary role in this matter. However, the causes for the superior performance of vein [...] grafts respect ePTFE remain unclear. Our aim was to compare the conduit (CF) and buffering function (BF) of arteries, with those of vein grafts and ePTFE. In vitro pressure (Konigsberg) and diameter (Sonomicrometry) were measured in ovine arteries and veins, and ePTFE prosthesis, under isobaric and physiological pressures levels. From stress-strain relationship the Kelvin-Voigt time constant was calculated to quantify the BF. The CF was evaluated as 1/Z C, where Z C is the characteristic impedance. Vein graft CF and BF were more similar to native arteries than those of ePTFE prosthesis. Consequently, the higher performance of vein grafts could be related with their superior matching with arteries.

  7. Electrospun and woven silk fibroin/poly(lactic-co-glycolic acid) nerve guidance conduits for repairing peripheral nerve injury

    Science.gov (United States)

    Wang, Ya-ling; Gu, Xiao-mei; Kong, Yan; Feng, Qi-lin; Yang, Yu-min

    2015-01-01

    We have designed a novel nerve guidance conduit (NGC) made from silk fibroin and poly(lactic-co-glycolic acid) through electrospinning and weaving (ESP-NGCs). Several physical and biological properties of the ESP-NGCs were assessed in order to evaluate their biocompatibility. The physical properties, including thickness, tensile stiffness, infrared spectroscopy, porosity, and water absorption were determined in vitro. To assess the biological properties, Schwann cells were cultured in ESP-NGC extracts and were assessed by morphological observation, the MTT assay, and immunohistochemistry. In addition, ESP-NGCs were subcutaneously implanted in the backs of rabbits to evaluate their biocompatibility in vivo. The results showed that ESP-NGCs have high porosity, strong hydrophilicity, and strong tensile stiffness. Schwann cells cultured in the ESP-NGC extract fluids showed no significant differences compared to control cells in their morphology or viability. Histological evaluation of the ESP-NGCs implanted in vivo indicated a mild inflammatory reaction and high biocompatibility. Together, these data suggest that these novel ESP-NGCs are biocompatible, and may thus provide a reliable scaffold for peripheral nerve repair in clinical application.

  8. Using the stress function in the flow of generalized Newtonian fluids through conduits with non-circular or multiply connected cross sections

    CERN Document Server

    Sochi, Taha

    2015-01-01

    We investigate the possibility that the spatial dependency of stress in generalized Newtonian flow systems is a function of the applied pressure field and the conduit geometry but not of the fluid rheology. This possibility is well established for the case of a one-dimensional flow through simply connected regions, specifically tubes of circular uniform cross sections and plane thin slits. If it can also be established for the more general case of generalized Newtonian flow through non-circular or multiply connected geometries, such as the two-dimensional flow through conduits of rectangular or elliptical cross sections or the flow through annular circular pipes, then analytical or semi-analytical or highly accurate numerical solutions; regarding stress, rate of strain, velocity profile and volumetric flow rate; for these geometries can be obtained from the stress function, which can be easily obtained from the Newtonian case, in combination with the constitutive rheological relation for the particular non-Ne...

  9. A cataluminescence-based vapor-sensitive sensor array for discriminating flammable liquid vapors.

    Science.gov (United States)

    Liu, Bowei; Kong, Hao; Luo, Aiqin

    2014-04-01

    This paper describes a cataluminescence-based (CTL-based) vapor-sensitive sensor array containing 10 kinds of catalytic nanoparticles for rapid detection and discrimination of 10 flammable liquid (FL) vapors. The catalytic nanoparticles are directly deposited on heating filaments with the formation of the sensing elements. When the vapor samples are imported to the sensor array with carrier gas, the CTL intensity varies with the nanoparticles. The fingerprints of 10 FL vapors are discriminated according to the distinct CTL response patterns through a linear discriminant analysis (LDA) and hierarchical cluster analysis (HCA) in SPSS (version 16.0). The canonical patterns are clearly clustered into 10 different groups with a classification accuracy of 100%. The sensor array also applies to several real-world samples. Two kinds of simulated actual vapors, originating from the combustion of carpet in the presence and absence of gasoline, can be effectively distinguished. The developed CTL-based vapor-sensitive sensor array offers a new strategy for the rapid detection of FL vapors owing to its stability, reversibility, portability and low costs. PMID:24607108

  10. Processing Film, Processing Meaning

    Science.gov (United States)

    Perkowski, Lisa M.

    2015-01-01

    Adolescents are at a ripe age to make meaning and think abstractly (Kerlavage, 1998); yet, they are not "born knowing how to get ideas into materials, or how materials can be manipulated to shape ideas and meaning" (Burton, 2012, p. 14). Adolescents need guidance in understanding abstract concepts, and art teachers play an important role…

  11. Morbidity and Quality of Life in Bladder Cancer Patients following Cystectomy and Urinary Diversion: A Single-Institution Comparison of Ileal Conduit versus Orthotopic Neobladder

    OpenAIRE

    Barbara Erber; Mark Schrader; Kurt Miller; Martin Schostak; Daniel Baumunk; Anja Lingnau; Andres Jan Schrader; Florian Jentzmik

    2012-01-01

    Objective. To evaluate and compare noncontinent and continent urinary diversion after radical cystectomy in patients with bladder cancer. Methods. A total of 301 patients submitted to radical cystectomy at the Charité-University Hospital Berlin from 1993 to 2007 including 146 with an ileal conduit and 115 with an ileal neobladder. Clinical and pathological data as well as oncological outcome were retrospectively analyzed and compared. Quality of life was analyzed using the EORTC QLQ-C30 and B...

  12. Enhancement of Median Nerve Regeneration by Mesenchymal Stem Cells Engraftment in an Absorbable Conduit: Improvement of Peripheral Nerve Morphology with Enlargement of Somatosensory Cortical Representation.

    Directory of Open Access Journals (Sweden)

    Julia Teixeira Oliveira

    2014-10-01

    Full Text Available We studied the morphology and the cortical representation of the median nerve (MN, 10 weeks after a transection immediately followed by treatment with tubulization using a polycaprolactone (PCL conduit with or without bone marrow-derived mesenchymal stem cell (MSC transplant. In order to characterize the cutaneous representation of MN inputs in primary somatosensory cortex (S1, electrophysiological cortical mapping of the somatosensory representation of the forepaw and adjacent body parts was performed after acute lesion of all brachial plexus nerves, except for the MN. This was performed in ten adult male Wistar rats randomly assigned in 3 groups: MN Intact (n=4, PCL-Only (n=3 and PCL+MSC (n=3. Ten weeks before mapping procedures in animals from PCL-Only and PCL+MSC groups, animal were subjected to MN transection with removal of a 4-mm-long segment, immediately followed by suturing a PCL conduit to the nerve stumps with (PCL+MSC group or without (PCL-Only group injection of MSC into the conduit. After mapping the representation of the MN in S1, animals had a segment of the regenerated nerve processed for light and transmission electron microscopy. For histomorphometric analysis of the nerve segment, sample size was increased to 5 animals per experimental group. The PCL+MSC group presented a higher number of myelinated fibers and a larger cortical representation of MN inputs in S1 (3,383±390 fibers; 2.3 mm2, respectively than the PCL-Only group (2,226±575 fibers; 1.6 mm2. In conclusion, MSC-based therapy associated with PCL conduits can improve MN regeneration. This treatment seems to rescue the nerve representation in S1, thus minimizing the stabilization of new representations of adjacent body parts in regions previously responsive to the MN.

  13. A Comparative Study of Fast-Track Verus Conventional Surgery in Patients Undergoing Laparoscopic Radical Cystectomy and Ileal Conduit Diversion: Chinese Experience

    OpenAIRE

    Guan, Xiao; LIU, LONGFEI; Lei, Xiang; Zu, Xiongbing; LI, YUAN; Chen, Mingfen; WANG, Long; Qi, Lin

    2014-01-01

    Fast-track surgery (FTS), which combines various techniques with evidence-based adjustments, is aimed to reduce postoperative morbidity, attenuate surgical stress response, thereby accelerating recovery and shorting length of stay. To further investigate the effectiveness of fast-track surgery, we compared the short-term outcomes of laparoscopic radical cystectomy and ileal conduit diversion for Chinese bladder cancer patients with FTS or with CS in our hospital. Patients with bladder cancer ...

  14. Expérimentation des écoulements diphasiques en conduites pétrolières : boucles d'essais de Boussens Two-Phase Flow Experimentation in Pipes : Test Loops At Boussens

    OpenAIRE

    Roux A.; Grouvel M.; Corteville J.; Lagiere M.

    2006-01-01

    Les deux boucles d'essais des écoulements diphasiques pétroliers en fonctionnement à Boussens, près de Toulouse, sont présentées brièvement. Ces équipements originaux permettent d'expérimenter les écoulements d'huile et de gaz associé ou de gaz à condensat en conditions pétrolières industrielles. La première boucle, mise au point en 1976, permet d'étudier les écoulements diphasiques horizontaux ou à faibles pentes qui prédominent dans les conduites de transport (collectes et pipelines terrest...

  15. A modular, plasmin-sensitive, clickable poly(ethylene glycol)-heparin-laminin microsphere system for establishing growth factor gradients in nerve guidance conduits.

    Science.gov (United States)

    Roam, Jacob L; Yan, Ying; Nguyen, Peter K; Kinstlinger, Ian S; Leuchter, Michael K; Hunter, Daniel A; Wood, Matthew D; Elbert, Donald L

    2015-12-01

    Peripheral nerve regeneration is a complex problem that, despite many advancements and innovations, still has sub-optimal outcomes. Compared to biologically derived acellular nerve grafts and autografts, completely synthetic nerve guidance conduits (NGC), which allow for precise engineering of their properties, are promising but still far from optimal. We have developed an almost entirely synthetic NGC that allows control of soluble growth factor delivery kinetics, cell-initiated degradability and cell attachment. We have focused on the spatial patterning of glial-cell derived human neurotrophic factor (GDNF), which promotes motor axon extension. The base scaffolds consisted of heparin-containing poly(ethylene glycol) (PEG) microspheres. The modular microsphere format greatly simplifies the formation of concentration gradients of reversibly bound GDNF. To facilitate axon extension, we engineered the microspheres with tunable plasmin degradability. 'Click' cross-linking chemistries were also added to allow scaffold formation without risk of covalently coupling the growth factor to the scaffold. Cell adhesion was promoted by covalently bound laminin. GDNF that was released from these microspheres was confirmed to retain its activity. Graded scaffolds were formed inside silicone conduits using 3D-printed holders. The fully formed NGC's contained plasmin-degradable PEG/heparin scaffolds that developed linear gradients in reversibly bound GDNF. The NGC's were implanted into rats with severed sciatic nerves to confirm in vivo degradability and lack of a major foreign body response. The NGC's also promoted robust axonal regeneration into the conduit. PMID:26352518

  16. Extension of in-situ stress test analysis to rapid hole evacuation at Yucca Mountain due to a network of open conduits

    Energy Technology Data Exchange (ETDEWEB)

    Davies, J.B.

    1994-01-01

    Yucca Mountain is underlain by tuffaceous rocks that are highly fractured and jointed. During drilling of bore-holes at Yucca Mountain there were numerous occurrences of lost circulation when whole mud was taken by the formation. This evidence suggests that parts of Yucca Mountain are controlled hydrologicaly by a network of open conduits along the existing joints and fractures. Also at Yucca Mountain, stress tests have been performed in-situ by charging a small section along the boreholes with an excess pressure head of water. For many of these tests, the initial drop in water head was so rapid that within seconds up to hundreds of meters of fall had occurred. The opening of fractures as the excess head increases has previously been proposed as an important factor in explaining the shape of the stress test curves at lower pressures. We propose that such induced hydraulic fractures, under increasing water heads, can grow to a length sufficient to intersect the existing network of open joints and fractures. We extend our previous model to incorporate flow out along these open conduits and examine the initial rapid drop in terms of these extended models. We show that this rapid evacuation model fits the observed data from many slug tests in wells in the vicinity of Yucca Mountain. This result is confirmation of the drilling evidence that a network of open conduits exists at various depths below the water table and over a large geographic region around Yucca Mountain.

  17. 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...

  18. 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

  19. 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...

  20. Physical vapor deposition of wear resistant coatings

    International Nuclear Information System (INIS)

    The three physical vapor deposition (PVD) processes of evaporation, ion plating, and sputtering, are considered, with emphasis on recent developments in these processes for the deposition of refractory hard compounds. The deposition of hard overlay coatings by PVD processes onto carbide and high-speed steel tools and the resulting machining data are presented. Other wear applications are discussed. (author)

  1. Droplet vaporization in supercritical pressure environments

    Science.gov (United States)

    Farrell, Patrick V.; Peters, Bruce D.

    For most liquid-fueled combustion systems the behavior of the fuel as it is introduced to the combustion zone, often by spray injection, will have a significant impact on combustion. The subsequent combustion may be affected to a considerable degree by the initial spread of the liquid, break-up of larger fuel sheets and droplets into droplets of various sizes, droplet vaporization, and diffusion of gaseous fuel. Among the many factors which affect spray break-up and droplet vaporization are the environmental conditions into which the spray is introduced. For both diesel engines and rockets the environment pressure and temperature may be above the critical pressure and temperature of the injected fuel. In a compression-ignition internal combustion engine, the environment consists primarily of air, at pressures from 20 to 100 atmospheres and temperatures ranging from 900 to 1500 K. Even higher pressures are encountered in turbocharged diesels. A typical diesel reference fuel, dodecane, has a thermodynamic critical pressure of about 17 atmospheres, and a critical temperature of 600 K. Fuel is injected into a diesel engine environment in which ambient pressures exceed the critical pressure. While droplet temperatures are subcritical at first, they may rise to the critical temperature or higher. This paper will survey current understanding of supercritical pressure droplet vaporization. Specifically, the topics covered will include: liquid phase behavior; vapor phase behavior; thermodynamic and transport properties; droplet distribution and break-up; micro-explosions; and effects of microgravity.

  2. Low-pressure, chemical vapor deposition polysilicon

    Science.gov (United States)

    Gallagher, B. D.; Crotty, G. C.

    1986-01-01

    The low-pressure chemical vapor deposition (LPCVD) of polycrystalline silicon was investigted. The physical system was described, as was the controlling process parameters and requirements for producing films for use as an integral portion of the solar cell contact system.

  3. Effectiveness of air vapor barriers combined with ventilated crawlspaces in decreasing residential exposure to radon daughters to radon daughters: preliminary report

    International Nuclear Information System (INIS)

    Radon gas is present in many homes. Concentrations may be increased in airtight, energy-efficient structures. This is especially true in cold climates where energy conservation is an important factor leading to the widespread application of sealing and tightening techniques both in older renovated homes and new construction. To reduce radon concentrations, it may be effective to ventilate crawlspaces and prevent infiltration of radon gas into the house by means of an air/vapor barrier. The authors report first results of comparing radon levels in homes with and without ventilated crawlspaces and air/vapor barriers. Radon emissions were measured in a tightly sealed home with ventilated crawlspaces and an air/vapor barrier and in two homes without such vapor barriers and ventilated crawlspaces, but differing in ventilation. Preliminary results suggest that use of ventilated crawlspaces and bottomside vapor barriers may reduce indoor radon levels by approximately 60%. 15 references, 1 table

  4. Radionuclide transport as vapor through unsaturated fractured rock

    International Nuclear Information System (INIS)

    Transport mechanisms potentially important at larger distances include ordinary diffusion, viscous flow, and free convection. Ordinary diffusion includes self and binary diffusion, Knudsen flow, and surface diffusion. Pressure flow and slip flow comprise viscous flow. Free convective flow results from a gas density contrast. Transport mechanisms or processes dominant near the repository include ordinary diffusion, viscous flow plus several mechanisms whose driving forces arise from the non-isothermal, radioactive nature of high-level waste. The additional mechanisms include forced diffusion, aerosol transport, thermal diffusion and thermophoresis. Near a repository, vapor transport mechanisms and processes can provide a significant means of transport from a failed canister to the geologic medium from which other processes can transport radionuclides to the accessible environment. These issues are believed to be important factors that must be addressed in the assessment of specific engineering designs and site selection of any proposed high-level waste repository. 95 refs., 43 figs., 10 tabs

  5. Excimer laser induced chemical vapor deposition of boron nitride films

    Energy Technology Data Exchange (ETDEWEB)

    Ageev, V.P.; Konov, V.I.; Ugarov, M.V. [General Physics Institute, Moscow (Russian Federation)

    1995-12-31

    The radiation of KrF pulsed excimer laser was used for the deposition of thin BN films from the vapor phase containing borazine (B{sub 3}N{sub 3}H{sub 6}). The dependencies of the film deposition rate upon borazine pressure, laser fluence and substrate were obtained. The composition and the structure of the deposited boron nitride was analysed by means of Raman scattering spectroscopy and Auger electron spectroscopy, which showed that stoichiometric hexagonal boron nitride is the main component of the deposited films. A simple deposition model is proposed, which takes into account chemisorption and partial decomposition of borazine molecules on the substrate surface between laser pulses and final decomposition of the intermediate product during the laser pulse.

  6. 33 CFR 154.808 - Vapor control system, general.

    Science.gov (United States)

    2010-07-01

    ...POLLUTION FACILITIES TRANSFERRING OIL OR HAZARDOUS MATERIAL IN BULK Vapor Control Systems § 154...or concentration indication required by this part must provide a...operated cargo vapor shutoff valve required by § 154.810(a) of...

  7. 33 CFR 154.826 - Vapor compressors and blowers.

    Science.gov (United States)

    2010-07-01

    ...Each inlet and outlet to a compressor or blower which handles...reciprocating or screw-type compressor handles vapor in the vapor... (1) Excessive discharge gas temperature at each compressor chamber or cylinder;...

  8. Water Vapor in an Unexpected Location

    Science.gov (United States)

    Kohler, Susanna

    2016-01-01

    The protoplanetary disk around DoAr 44 is fairly ordinary in most ways. But a recent study has found that this disk contains water vapor in its inner regions the first such discovery for a disk of its type.Drying Out DisksDoAr 44 is a transitional disk: a type of protoplanetary disk that has been at least partially cleared of small dust grains in the inner regions of the disk. This process is thought to happen as a result of dynamical interactions with a protoplanet embedded in the disk; the planet clears out a gap as it orbits.A schematic of the differences between a full protoplanetary disk, a pre-transitional disk, and a transitional disk. [Catherine Espaillat]Classical protoplanetary disks surrounding young, low-mass stars often contain water vapor, but transitional disks are typically dry no water vapor is detected from the disk inner regions. This is probably because water vapor is easily dissociated by far-UV radiation from the young, hot star. Once the dust is cleared out from the inner regions of the disk, the water vapor is no longer shielded from the UV radiation, so the disk dries out.Enter the exception: DoAr 44. The disk in this system doesnt have a fully cleared inner region, which labels it pre-transitional. Its composed of an inner ring out to 2 AU, a cleared gap between 2 and 36 AU, and then the outer disk. What makes DoAr 44 unusual, however, is that its the only disk with a large inner gap known to harbor detectable quantities of water vapor. The authors of this study ask a key question: where is this water vapor located?Unusual SystemLed by Colette Salyk (NOAO and Vassar College), the authors examined the system using the Texas Echelon Cross Echelle Spectrograph, a visiting instrument on the Gemini North telescope. They discovered that the water vapor emission originates from about 0.3 AU the inner disk region, where terrestrial-type planets may well be forming.Both dust-shielding and water self-shielding seem to have protected this water vapor from the harsh radiation of the central star, and the authors model this shielding to place constraints on the composition of the disks inner regions. They conclude that DoAr 44 has maintained similar physical and chemical conditions to classical protoplanetary disks in its terrestrial-planet forming regions, in spite of having formed a large gap.Why has DoAr 44 succeeded at maintaining its water vapor, unlike other transition disks? The authors propose that gas might be migrating across the gap in the disk, replenishing the inner disk from the outer. Future observations are planned to help better understand the overall architecture of the gap, as well as the implications of these detections for any possible planets embedded in the disk.CitationColette Salyk et al 2015 ApJ 810 L24. doi:10.1088/2041-8205/810/2/L24

  9. Water Vapor in an Unexpected Location

    Science.gov (United States)

    Kohler, Susanna

    2015-09-01

    The protoplanetary disk around DoAr 44 is fairly ordinary in most ways. But a recent study has found that this disk contains water vapor in its inner regions the first such discovery for a disk of its type.Drying Out DisksDoAr 44 is a transitional disk: a type of protoplanetary disk that has been at least partially cleared of small dust grains in the inner regions of the disk. This process is thought to happen as a result of dynamical interactions with a protoplanet embedded in the disk; the planet clears out a gap as it orbits.A schematic of the differences between a full protoplanetary disk, a pre-transitional disk, and a transitional disk. [Catherine Espaillat] Classical protoplanetary disks surrounding young, low-mass stars often contain water vapor, but transitional disks are typically dry no water vapor is detected from the disk inner regions. This is probably because water vapor is easily dissociated by far-UV radiation from the young, hot star. Once the dust is cleared out from the inner regions of the disk, the water vapor is no longer shielded from the UV radiation, so the disk dries out.Enter the exception: DoAr 44. The disk in this system doesnt have a fully cleared inner region, which labels it pre-transitional. Its composed of an inner ring out to 2 AU, a cleared gap between 2 and 36 AU, and then the outer disk. What makes DoAr 44 unusual, however, is that its the only disk with a large inner gap known to harbor detectable quantities of water vapor. The authors of this study ask a key question: where is this water vapor located?Unusual SystemLed by Colette Salyk (NOAO and Vassar College), the authors examined the system using the Texas Echelon Cross Echelle Spectrograph, a visiting instrument on the Gemini North telescope. They discovered that the water vapor emission originates from about 0.3 AU the inner disk region, where terrestrial-type planets may well be forming.Both dust-shielding and water self-shielding seem to have protected this water vapor from the harsh radiation of the central star, and the authors model this shielding to place constraints on the composition of the disks inner regions. They conclude that DoAr 44 has maintained similar physical and chemical conditions to classical protoplanetary disks in its terrestrial-planet forming regions, in spite of having formed a large gap.Why has DoAr 44 succeeded at maintaining its water vapor, unlike other transition disks? The authors propose that gas might be migrating across the gap in the disk, replenishing the inner disk from the outer. Future observations are planned to help better understand the overall architecture of the gap, as well as the implications of these detections for any possible planets embedded in the disk.CitationColette Salyk et al 2015 ApJ 810 L24. doi:10.1088/2041-8205/810/2/L24

  10. The vapor pressure and enthalpy of vaporization of M-xylene

    International Nuclear Information System (INIS)

    We measured the vapor pressure of m-xylene over the temperature range 273 to 293 deg K with a single-sided capacitance manometer. The enthalpy of vaporization was 42.2 ± 0.1 (SE) kj/ g·mol. Combining our own data with previously published data, we recommend using the values 42.0, 40.6, and 39.1 (± 0.1) (SE) kjg·mol for the enthalpy of vaporization of m-xylene at 300, 340, and 380 deg. K, respectively, and a value for the change in heat capacity on vaporization (?Cpdeg.) of 35 ± 3 (SE) J/g·mol·K over the temperature range studied. (author)

  11. 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....

  12. Relationship between vapor intrusion and human exposure to trichloroethylene.

    Science.gov (United States)

    Archer, Natalie P; Bradford, Carrie M; Villanacci, John F; Crain, Neil E; Corsi, Richard L; Chambers, David M; Burk, Tonia; Blount, Benjamin C

    2015-11-10

    Trichloroethylene (TCE) in groundwater has the potential to volatilize through soil into indoor air where it can be inhaled. The purpose of this study was to determine whether individuals living above TCE-contaminated groundwater are exposed to TCE through vapor intrusion. We examined associations between TCE concentrations in various environmental media and TCE concentrations in residents. For this assessment, indoor air, outdoor air, soil gas, and tap water samples were collected in and around 36 randomly selected homes; blood samples were collected from 63 residents of these homes. Additionally, a completed exposure survey was collected from each participant. Environmental and blood samples were analyzed for TCE. Mixed model multiple linear regression analyses were performed to determine associations between TCE in residents' blood and TCE in indoor air, outdoor air, and soil gas. Blood TCE concentrations were above the limit of quantitation (LOQ; ? 0.012 µg L(-1)) in 17.5% of the blood samples. Of the 36 homes, 54.3%, 47.2%, and >84% had detectable concentrations of TCE in indoor air, outdoor air, and soil gas, respectively. Both indoor air and soil gas concentrations were statistically significantly positively associated with participants' blood concentrations (P = 0.0002 and P = 0.04, respectively). Geometric mean blood concentrations of residents from homes with indoor air concentrations of >1.6 µg m(-3) were approximately 50 times higher than geometric mean blood TCE concentrations in participants from homes with no detectable TCE in indoor air (P exposure from vapor intrusion of TCE in a residential setting. PMID:26259926

  13. Q Conversion Factor Models for Estimating Precipitable Water Vapor for Turkey

    Science.gov (United States)

    Deniz, Ilke; Mekik, Cetin; Gurbuz, Gokhan

    2015-04-01

    Global Navigation Satellite Systems (GNSS) have recently proved to be one of the crucial tools for determining continuous and precise precipitable water vapor (GNSS-MET networks). GNSS, especially CORS networks such as CORS-TR (the Turkish Network-RTK), provide high temporal and spatial accuracy for the wet tropospheric zenith delays which are then converted to the precipitable water vapor due to the fact that they can operate in all weather conditions continuously and economically. The accuracy of wet tropospheric zenith delay highly depends on the accuracy of precipitable water vapor content in the troposphere. Therefore, the precipitable water vapor is an important element of the tropospheric zenith delay. A number of studies can be found in the literature on the determination of the precipitable water vapor from the tropospheric zenith delay. Studies of Hogg showed that when the precipitable water vapor is known, the tropospheric zenith delay can be computed. Askne and Nodius have developed fundamental equations between the wet tropospheric zenith delay and the precipitable water vapor from the equation of the index of refraction in the troposphere. Furthermore, Bevis have developed a linear regression model to determine the weighted mean temperature (Tm) depending on the surface temperature (Ts) in Askne and Nodius studies. For this reason, nearly 9000 radiosonde profiles in USA were analyzed and the coefficients calculated. Similarly, there are other studies on the calculation of those coefficients for different regions: Solbrig for Germany, Liou for Taiwan, Jihyun for South Korea, Dongseob for North Korea, Suresh Raju for India, Boutiouta and Lahcene for Algeria, Bokoye for Canada, Baltink for Netherlands and Baltic, Bock for Africa. It is stated that the weighted mean temperature can be found with a root mean square error of ±2-5 K. In addition, there are studies on the calculation of the coefficients globally. Another model for the determination of precipitable water vapor is the conversion factor Q which is shown in Emardson and Derks' studies and also Jade and Vijayan's. Developing a regional model using either Tm-Ts equation or the conversion factor Q will provide a basis for GNSS Meteorology in Turkey which depends on the analysis of the radiosonde profile data. For this purpose, the radiosonde profiles from Istanbul, Ankara, Diyarbaki r, Samsun, Erzurum, Izmir, Isparta and Adana stations are analyzed with the radiosonde analysis algorithm in the context of the 'The Estimation of Atmospheric Water Vapour with GPS' Project which is funded by the Scientific and Technological Research Council of Turkey (TUBITAK). The Project is also in the COST Action ES1206: Advanced Global Navigation Satellite Systems tropospheric products for monitoring severe weather events and climate (GNSS4SWEC). In this study, regional models using the conversion factor Q are used for the determination of precipitable water vapor, and applied to the GNSS derived wet tropospheric zenith delays. Henceforth, the estimated precipitable water vapor and the precipitable water vapor obtained from the radiosonde station are compared. The average of the differences between RS and models for Istanbul and Ankara stations are obtained as 2.0±1.6 mm, 1.6±1.6 mm, respectively.

  14. Method and apparatus for measuring vapor flow in isotope separation

    International Nuclear Information System (INIS)

    A probe for detecting the evaporation rate of an electron beam evaporation source and for monitoring induced ionization of the vapor is claimed. A negatively biased electrode responds to ions in the vapor to measure the ion current density. The ions measured may result from the process of vaporization or from laser produced isotopically selective ionization. The probe provides a current output which is detected as an indication of vaporization or laser ionization rate

  15. 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...

  16. Thermodynamics of means

    OpenAIRE

    Lavenda, B. H.

    2004-01-01

    Thermodynamics of power means applies to an ideal quantum gas which may be nonextensive. Transition to an ideal classical gas occurs when the empirical temperature exponents of the internal energy and absolute temperature coalesce. Limiting processes are pure heat conduction and pure deformations. Largest and smallest mean final volumes occur for isothermal and adiabatic processes, respectively. The increment in the heat admits two integrating factors which yield conserved q...

  17. 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

  18. Effect of water vapor and hydrogen treatments on the surface structure of Ni3Al foil

    International Nuclear Information System (INIS)

    Highlights: • A water vapor treatment followed by H2 reduction was developed for modify the surface structure of Ni3Al foils. • Fine NiO particles with a high density were formed on the surface by the water vapor treatment. • The NiO particles were reduced to Ni by the subsequent H2 reduction, forming a Ni-enriched porous-like surface structure. - Abstract: We have developed a water vapor treatment followed by hydrogen reduction to modify the surface structure of Ni3Al foils in order to obtain high catalytic activity. The Ni3Al foils were heat treated in water vapor at 873 K for 1 h followed by H2 reduction at 873 K for 1 h. The effects of the water vapor treatment and the H2 reduction on the surface structure of the Ni3Al foils were investigated by means of scanning electron microscopy and synchrotron radiation X-ray photoemission spectroscopy. Both Ni and Al in the surface layer of the Ni3Al foil were oxidized during the water vapor treatment; fine NiO particles with a high density were formed on the outermost surface, accompanied by the formation of oxide layers of Al(OH)3 and NiAl2O4/Al2O3 beneath the NiO particles. The NiO particles were reduced to metallic Ni and the Al(OH)3 was decomposed to Al2O3, whereas the NiAl2O4 and Al2O3 remained unchanged during the subsequent H2 reduction, forming a Ni-enriched porous structure on the surface layer of NiAl2O4/Al2O3

  19. Particle/vapor concentrations and distributions of PAHs in the atmosphere of southern Chesapeake Bay

    International Nuclear Information System (INIS)

    Atmospheric PAH concentrations were measured at four sites characterized as rural (Haven Beach), semiurban (York River), urban (Hampton), and industrialized (Elizabeth River) areas as part of a study to quantify gaseous exchange fluxes across the air-water interface of southern Chesapeake Bay. Aerosol particle-associated PAH concentrations were similar at all sites; however, PAH vapor concentrations in the urban areas were as much as a factor of 50 greater than those at the rural site. Mean total PAH concentrations ranged from 7.87 ng/m3 at the rural site to 92.8 ng/m3 at the urban site. Daily total PAH concentrations ranged from 1.60 to 198 ng/m3. Exponential increases in PAH vapor concentrations with temperature were observed at the non-rural sites, suggesting volatilization from contaminated surfaces during warmer weather; whereas PAH vapor concentrations at the rural Haven Beach site exhibited little seasonal variability. Aerosol particle-associated PAH levels were similar at all sites and increased in winter due to the temperature dependence of vapor-particle partitioning, increased sources from combustion of fossil fuel and wood for home heating, and cold condensation of source vapors to background aerosols as air masses are dispersed to remote regions. Plots of log Kd vs. log Psat,SC1 indicate PAH partitioning is not at equilibrium in rural areas of Southern Chesapeake Bay. In addition, plots of log Kd vs. 1/T for individual PAHs indicate difference particle characteristics or partitioning processes influence particle/vapor distributions at the urban and rural sites

  20. Vapor-modulated heat pipe for improved temperature control

    Science.gov (United States)

    Edwards, D. K.; Eninger, J. E.; Ludeke, E. E.

    1978-01-01

    Dryout induced by vapor throttling makes control of equipment temperature less dependent on variations in sink environment. Mechanism controls flow of vapor in heat pipe by using valve in return path to build difference in pressure and also difference in saturation temperature of the vapor. In steady state, valve closes just enough to produce partial dryout that achieves required temperature drop.

  1. Passive heat transfer means for nuclear reactors

    Science.gov (United States)

    Burelbach, James P. (Glen Ellyn, IL)

    1984-01-01

    An improved passive cooling arrangement is disclosed for maintaining adjacent or related components of a nuclear reactor within specified temperature differences. Specifically, heat pipes are operatively interposed between the components, with the vaporizing section of the heat pipe proximate the hot component operable to cool it and the primary condensing section of the heat pipe proximate the other and cooler component operable to heat it. Each heat pipe further has a secondary condensing section that is located outwardly beyond the reactor confinement and in a secondary heat sink, such as air ambient the containment, that is cooler than the other reactor component. Means such as shrouding normally isolated the secondary condensing section from effective heat transfer with the heat sink, but a sensor responds to overheat conditions of the reactor to open the shrouding, which thereby increases the cooling capacity of the heat pipe. By having many such heat pipes, an emergency passive cooling system is defined that is operative without electrical power.

  2. Membrane-assisted vapor stripping: energy efficient hybrid distillation-vapor permeation process for alcohol-water separation

    Science.gov (United States)

    BACKGROUND: Energy efficient alternatives to distillation for alcohol recovery from dilute solution are needed to improve biofuel sustainability. A process integrating steam stripping with a vapor compression step and a vapor permeation membrane separation step is proposed. The...

  3. The vaporization enthalpy and vapor pressure of S (+)-methamphetamine at T = 298.15 K by correlation gas chromatography

    International Nuclear Information System (INIS)

    Highlights: • The vaporization enthalpy of (d)-methamphetamine was measured. • The vapor pressure of (d)-methamphetamine as a function of temperature was evaluated. • The vapor pressure of 4-benzylpiperidine as a function of temperature was evaluated. - Abstract: The vaporization enthalpy and vapor pressure of S (+)-methamphetamine is evaluated by correlation-gas chromatography. A vaporization enthalpy of (58.7 ± 4.3) kJ · mol?1 and a vapor pressure, p = (38 ± 9) Pa has been obtained using a variety of secondary aliphatic amines as standards. In addition, equations describing the vapor pressure temperature dependence are provided for standards and S (+)-methamphetamine covering the temperature range from T = 298.15 K to the boiling temperature. Boiling temperatures are reproduced within an interval of 8 K or less

  4. 77 FR 28772 - Air Quality: Widespread Use for Onboard Refueling Vapor Recovery and Stage II Waiver

    Science.gov (United States)

    2012-05-16

    ...2060-AQ97 Air Quality: Widespread Use for Onboard Refueling Vapor Recovery and Stage II...SUMMARY: The EPA has determined that onboard refueling vapor recovery (ORVR) technology...Stage II Vapor Recovery Systems C. Onboard Refueling Vapor Recovery (ORVR)...

  5. 76 FR 41731 - Air Quality: Widespread Use for Onboard Refueling Vapor Recovery and Stage II Waiver

    Science.gov (United States)

    2011-07-15

    ...2060-AQ97 Air Quality: Widespread Use for Onboard Refueling Vapor Recovery and Stage II...proposing criteria for determining whether onboard refueling vapor recovery (ORVR) is in...Stage II Vapor Recovery Systems C. Onboard Refueling Vapor Recovery...

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

    Science.gov (United States)

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

    2015-04-01

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

  7. Computational modeling of lava domes using particle dynamics to investigate the effect of conduit flow mechanics on flow patterns

    Science.gov (United States)

    Husain, Taha Murtuza

    Large (1--4 x 106 m3) to major (> 4 x 106 m3) dome collapses for andesitic lava domes such as Soufriere Hills Volcano, Montserrat are observed for elevated magma discharge rates (6--13 m3/s). The gas rich magma pulses lead to pressure build up in the lava dome that result in structural failure of the over steepened canyon-like walls which may lead to rockfall or pyroclastic flow. This indicates that dome collapse intimately related to magma extrusion rate. Variation in magma extrusion rate for open-system magma chambers is observed to follow alternating periods of high and low activity. Periodic behavior of magma exhibits a rich diversity in the nature of its eruptive history due to variation in magma chamber size, total crystal content, linear crystal growth rate and magma replenishment rate. Distinguished patterns of growth were observed at different magma flow rates ranging from endogenous to exogenous dome growth for magma with varying strengths. Determining the key parameters that control the transition in flow pattern of the magma during its lava dome building eruption is the main focus. This dissertation examines the mechanical effects on the morphology of the evolving lava dome on the extrusion of magma from a central vent using a 2D particle dynamics model. The particle dynamics model is coupled with a conduit flow model that incorporates the kinetics of crystallization and rheological stiffening to investigate important mechanisms during lava dome building eruptions. Chapter I of this dissertation explores lava dome growth and failure mechanics using a two-dimensional particle-dynamics model. The model follows the evolution of fractured lava, with solidification driven by degassing induced crystallization of magma. The particle-dynamics model emulates the natural development of dome growth and rearrangement of the lava dome which is difficult in mesh-based analyses due to mesh entanglement effects. The deformable talus evolves naturally as a frictional carapace that caps a ductile magma core. Extrusion rate and magma rheology together with crystallization temperature and volatile content govern the distribution of strength in the composite structure. This new model is calibrated against existing observational models of lava dome growth. Chapter II of this dissertation explores the effects of a spectrum of different rheological regimes, on eruptive style and morphologic evolution of lava domes, using a two-dimensional (2D) particle-dynamics model for a spreading viscoplastic (Bingham) fluid. We assume that the ductile magma core of a 2-D synthetic lava dome develops finite yield strength, and that deformable frictional talus evolves from a carapace that caps the magma core. Our new model is calibrated against an existing analytical model for a spreading viscoplastic lava dome and is further compared against observational data of lava dome growth. Chapter III of this dissertation explores different lava-dome styles by developing a two-dimensional particle-dynamics model. These growth patterns range from endogenous lava dome growth comprising expansion of a ductile dome core to the exogenous extrusion of a degassed lava plug resulting in generation of a lava spine. We couple conduit flow dynamics with surface growth of the evolving lava dome, fueled by an open-system magma chamber undergoing continuous replenishment. The conduit flow model accounts for the variation in rheology of ascending magma that results from degassing-induced crystallization. Chapter IV of this dissertation explores the Variation in the extruding lava flow patterns range from endogenous dome growth with a ductile core to the exogenous extrusion of a degassed lava plug that results in the generation of a spine. The variations are a manifestation of the changes in the magma rheology which is governed by magma composition and rate of decompression of the ascending magma. We simulate using a two-dimensional particle-dynamics model, the cyclic behavior of lava dome growth with endogenous growth at high discharge rates followed by exogenous ex

  8. Differential absorption lidar measurements of atmospheric water vapor using a pseudonoise code modulated AlGaAs laser. Thesis

    Science.gov (United States)

    Rall, Jonathan A. R.

    1994-01-01

    Lidar measurements using pseudonoise code modulated AlGaAs lasers are reported. Horizontal path lidar measurements were made at night to terrestrial targets at ranges of 5 and 13 km with 35 mW of average power and integration times of one second. Cloud and aerosol lidar measurements were made to thin cirrus clouds at 13 km altitude with Rayleigh (molecular) backscatter evident up to 9 km. Average transmitter power was 35 mW and measurement integration time was 20 minutes. An AlGaAs laser was used to characterize spectral properties of water vapor absorption lines at 811.617, 816.024, and 815.769 nm in a multipass absorption cell using derivative spectroscopy techniques. Frequency locking of an AlGaAs laser to a water vapor absorption line was achieved with a laser center frequency stability measured to better than one-fifth of the water vapor Doppler linewidth over several minutes. Differential absorption lidar measurements of atmospheric water vapor were made in both integrated path and range-resolved modes using an externally modulated AlGaAs laser. Mean water vapor number density was estimated from both integrated path and range-resolved DIAL measurements and agreed with measured humidity values to within 6.5 percent and 20 percent, respectively. Error sources were identified and their effects on estimates of water vapor number density calculated.

  9. Compound nuclear decay and the liquid to vapor phase transition: a physical picture

    OpenAIRE

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

    2005-01-01

    Analyses of multifragmentation in terms of the Fisher droplet model (FDM) and the associated construction of a nuclear phase diagram bring forth the problem of the actual existence of the nuclear vapor phase and the meaning of its associated pressure. We present here a physical picture of fragment production from excited nuclei that solves this problem and establishes the relationship between the FDM and the standard compound nucleus decay rate for rare particles emitted in ...

  10. Development of a miniature vapor compression refrigeration system for electronic cooling

    OpenAIRE

    Davies, GF; Eames, IW; Bailey, PB; Dadd, MW; Janiszewski, A; Stone, CR; Maidment, GG; Agnew, B.

    2010-01-01

    Computer chips have generally been cooled by means of a heat sink/fan device; however, such systems are now approaching their limits and in future alternative techniques/devices will be needed. A 3-year project, involving collaboration between groups at three UK universities, is being undertaken to develop a miniature refrigeration device for the cooling of future microprocessors and electronic systems. Using conventional vapor compression refrigeration technology for the cooling of small com...

  11. Direct dry transfer of chemical vapor deposition graphene to polymeric substrates

    OpenAIRE

    Fechine, Guilhermino J. M.; Martin-Fernandez, Inigo; Yiapanis, George; de Oliveira, Ricardo V. Bof; Hu, Xiao; Yarovsky, Irene; Neto, Antonio. H. Castro; Ozyilmaz, Barbaros

    2014-01-01

    We demonstrate the direct dry transfer of large area Chemical Vapor Deposition graphene to several polymers (low density polyethylene, high density polyethylene, polystyrene, polylactide acid and poly(vinylidenefluoride-co-trifluoroethylene) by means of only moderate heat and pressure, and the later mechanical peeling of the original graphene substrate. Simulations of the graphene-polymer interactions, rheological tests and graphene transfer at various experimental condition...

  12. Theoretical calculation of electronic stopping power of water vapor by proton impact

    International Nuclear Information System (INIS)

    The energy loss of proton beams in water vapor is analyzed with a full quantum-mechanical treatment, the distorted-wave model. This model takes into account distortion effects due to the long-range Coulomb potential. Projectile energies from 10 keV up to 1 MeV are considered. Mean stopping power and equilibrium charge-state fractions are calculated and compared with experimental data. The validity of Bragg's additivity rule is investigated. 35 refs., 5 figs

  13. Synthesis of Carbon Nano Tubes on Silicon Substrates Using Alcohol Catalytic Chemical Vapor Deposition

    OpenAIRE

    Mohammad Abu-Abdeen; Abdu Aljaafari

    2011-01-01

    The technique used for synthesizing large quantity carbon nanotubes (CNTs) directly on the surface of silicon substrates has been developed by means of the alcohol catalyst chemical vapor deposition ACCVD method using ethanol. The proposed method adopts an easy and costless liquid-based dip-coat approach for mounting the catalytic metals on the substrates. Reasonable quality formation of catalyst preparation was found at 5 min of dipping the substrate into cobalt acetate solution and withdraw...

  14. Are climate-related changes to the character of global-mean precipitation predictable?

    International Nuclear Information System (INIS)

    The physical basis for the change in global-mean precipitation projected to occur with the warming associated with increased greenhouse gases is discussed. The expected increases to column water vapor W control the rate of increase of global precipitation accumulation through its affect on the planet's energy balance. The key role played by changes to downward longwave radiation controlled by this changing water vapor is emphasized. The basic properties of molecular absorption by water vapor dictate that the fractional rate of increase of global-mean precipitation must be significantly less that the fractional rate of increase in water vapor and it is further argued that this reduced rate of precipitation increase implies that the timescale for water re-cycling is increased in the global mean. This further implies less frequent precipitation over a fixed period of time, and the intensity of these less frequent precipitating events must subsequently increase in the mean to realize the increased global accumulation. These changes to the character of global-mean precipitation, predictable consequences of equally predictable changes to W, apply only to the global-mean state and not to the regional or local scale changes in precipitation.

  15. Mean-periodic functions

    Directory of Open Access Journals (Sweden)

    B. A. Taylor

    1980-06-01

    Full Text Available We show that any mean-periodic function f can be represented in terms of exponential-polynomial solutions of the same convolution equation f satisfies, i.e., u∗f=0(μ∈E′(ℝn. This extends to n-variables the work of L. Schwartz on mean-periodicity and also extends L. Ehrenpreis' work on partial differential equations with constant coefficients to arbitrary convolutors. We also answer a number of open questions about mean-periodic functions of one variable. The basic ingredient is our work on interpolation by entire functions in one and several complex variables.

  16. The construction of meaning.

    Science.gov (United States)

    Kintsch, Walter; Mangalath, Praful

    2011-04-01

    We argue that word meanings are not stored in a mental lexicon but are generated in the context of working memory from long-term memory traces that record our experience with words. Current statistical models of semantics, such as latent semantic analysis and the Topic model, describe what is stored in long-term memory. The CI-2 model describes how this information is used to construct sentence meanings. This model is a dual-memory model, in that it distinguishes between a gist level and an explicit level. It also incorporates syntactic information about how words are used, derived from dependency grammar. The construction of meaning is conceptualized as feature sampling from the explicit memory traces, with the constraint that the sampling must be contextually relevant both semantically and syntactically. Semantic relevance is achieved by sampling topically relevant features; local syntactic constraints as expressed by dependency relations ensure syntactic relevance. PMID:25164299

  17. Comparison of GPS precipitable water vapor and meteorological parameters during rainfalls in Tehran

    Science.gov (United States)

    Sharifi, Mohammad Ali; Sam Khaniani, Ali; Joghataei, Mohammad

    2015-12-01

    In this study, the sensing of water vapor using the global positioning system (GPS) was investigated in Tehran. Water vapor mean temperature T m is a key parameter in conversion of GPS zenith wet delay to precipitable water vapor (PWV). Then, by using 8 years of radiosonde and surface temperature data, we achieved a new site-specific T m model in Tehran. After the comparison of Bevis et al. (J Geophys Res 97(D14):15787-15801, 1992) and the site-specific models, a mean bias error of -1.3 K was found for Bevis model, while this is less than 0.1 K for the new local model. Therefore, PWV time series were generated for the ground-based GPS site in Tehran from the beginning of 2005 to the end of 2013. Comparing the GPS with the radiosonde PWV, it was shown that the GPS can be used to measure the PWV with high precision. The root mean square error for differences between the GPS and radiosonde was derived as 1.5 mm. The PWV has significant relationship with precipitation in our case study. The thresholds of the relative humidity anomaly with different PWV anomaly related to rainfall occurrences are also considered in this research. The analyses show that use of PWV anomaly condition together with surface meteorological parameters reduces the number of false rainfall recognitions significantly.

  18. Meaning in Matter

    DEFF Research Database (Denmark)

    Brix, Anders

    When addressing present-day challenges, design discourse put faith mainly in design understood as a problem-solving activity, pertaining to innovation on functional, systems and technological level. The aesthetically founded fields, e.g. craft-based design, on the other hand, do not seem to play any significant role in the larger scheme of strategic thinking. Thus, design as an art-form runs in the undercurrent of 'real' meaning, sometimes applauded as high fashion, but mainly framed as an excessive and superflouous feature added onto objects for entertainment and pleasure. In short, discourse isolate aesthetics from proper thinking. Looked at more closely, though, aesthetics is not a detached quality, separable from real, functional or, in deed, any other kind of meaning. From findings in recent neuroscience as well as related philosophy and psycholog, we now know that it is in fact the other way round: meaning as such is _grounded_ in aesthetics. Aesthetics, therefore, is properly the study of everything that goes into human meaning-making. Based on a review of the architecture of our cognitive functions, this paper proposes a new foundation for design-theory, a theory placing aesthetics central to design-discourse, design-practice and to strategies addressing global challenges. Such a foundation can assist in collecting efforts in and advancing the architectonic arts - especially in articulating these as knowledge production and scholarly research. This could provide art and design with a basis for entering strategic discussions. And it could help restore virtues often regarded as obsolete, but perhaps more central to the advancement of material culture than we generally realize. As it's field of inquiry, the paper takes the class of our physical world of objects - in particular those which carry _corporeal affordance_, such as clothing, blankets, chairs, tables and houses - perhaps even cities. Things that mean to us, what they mean, mainly _qua_ their physical properties.

  19. Dynamics of viscous coalescing droplets in a saturated vapor phase

    CERN Document Server

    Baroudi, Lina; Morris, Jeffrey F; Lee, Taehun

    2015-01-01

    The dynamics of two liquid droplets coalescing in their saturated vapor phase are investigated by Lattice Boltzmann numerical simulations. Attention is paid to the effect of the vapor phase on the formation and growth dynamics of the liquid bridge in the viscous regime. We observe that the onset of the coalescence occurs earlier and the expansion of the bridge initially proceeds faster when the coalescence takes place in a saturated vapor compared to the coalescence in a non-condensable gas. We argue that the initially faster evolution of the coalescence in the saturated vapor is caused by the vapor transport through condensation during the early stages of the coalescence.

  20. Computing meaning 4

    CERN Document Server

    2013-01-01

    This book is a collection of papers by leading researchers in computational semantics. It presents a state-of-the-art overview of recent and current research in computational semantics, including descriptions of new methods for constructing and improving resources for semantic computation, such as WordNet, VerbNet, and semantically annotated corpora. It also presents new statistical methods in semantic computation, such as the application of distributional semantics in the compositional calculation of sentence meanings. Computing the meaning of sentences, texts, and spoken or texted dialogue i

  1. Anisotropic Nonlocal Means Denoising

    CERN Document Server

    Maleki, Arian; Baraniuk, Richard G

    2011-01-01

    It has recently been proved that the popular nonlocal means (NLM) denoising algorithm does not optimally denoise images with sharp edges. Its weakness lies in the isotropic nature of the neighborhoods it uses to set its smoothing weights. In response, in this paper we introduce several theoretical and practical anisotropic nonlocal means (ANLM) algorithms and prove that they are near minimax optimal for edge-dominated images from the Horizon class. On real-world test images, an ANLM algorithm that adapts to the underlying image gradients outperforms NLM by a significant margin.

  2. Pumping effectiveness of a magnesium vapor jet in the presence of a high power neutral beam source

    International Nuclear Information System (INIS)

    An experimental study of a superconic magnesium vapor jet neutralizer has established the effectiveness of the jet in reducing cold streaming gas from a high current neutral beam source. The removal of molecular hydrogen gas by a magnesium jet neutralizer provides a means of simplifying beamline design by improved pumping characteristics of the jet compared with conventional technology while simulataneously improving performance

  3. Measurement of mean inner potential and inelastic mean free path of ZnO nanowires and nanosheet

    Science.gov (United States)

    Gan, Zhaofeng; Ahn, Seungho; Yu, Hongbin; Smith, David J.; McCartney, Martha R.

    2015-10-01

    ZnO nanowires (NWs) and ZnO nano-sheets were grown using the chemical vapor deposition method. The NW structure was characterized using transmission electron microscopy, while the mean inner potential and inelastic mean free path for 200 keV electrons were measured using off-axis electron holography to be 15.3 ± 0.2 V and 55 ± 3 nm, respectively. These values were then used to characterize the thickness of a ZnO nano-sheet, and gave consistent results. This study demonstrates that electron holography can provide useful information about nanostructured ZnO materials and devices.

  4. Flow Characterization of Vapor Phase of Geothermal Fluid in Pipe Using Isotope 85Kr and Residence Time Distribution Modeling

    Directory of Open Access Journals (Sweden)

    S. Sugiharto

    2014-08-01

    Full Text Available Measurement of vapor flow in geothermal pipe faces great challenges due to fast fluids flow in high-temperature and high-pressure environment. In present study the flow rate measurement has been performed to characterization the geothermal vapor flow in a pipe. The experiment was carried out in a pipe which is connected to a geothermal production well, KMJ-14. The pipe has a 10” outside diameter and contains dry vapor at a pressure of 8 kg/cm2 and a temperature of 170 oC. Krypton-85 gas isotope (85Kr has been injected into the pipe. Three collimated radiation detectors positioned respectively at 127, 177 and 227m from injection point were used to obtain experimental data which represent radiotracer residence time distribution (RTD in the pipe. The last detector at the position of 227 m did not respond, which might be due to problems in cable connections. Flow properties calculated using mean residence time (MRT shows that the flow rate of the vapor in pipe is 10.98 m/s, much faster than fluid flow commonly found in various industrial process plants. Best fitting evaluated using dedicated software developed by IAEA expert obtained the Péclet number Pe as 223. This means that the flow of vapor of geothermal fluids in pipe is plug flow in character. The molecular diffusion coefficient is 0.45 m2/s, calculated from the axial dispersion model.

  5. Flow Characterization of Vapor Phase of Geothermal Fluid in Pipe Using Isotope 85Kr and Residence Time Distribution Modeling

    International Nuclear Information System (INIS)

    Measurement of vapor flow in geothermal pipe faces great challenges due to fast fluids flow in high-temperature and high-pressure environment. In present study the flow rate measurement has been performed to characterization the geothermal vapor flow in a pipe. The experiment was carried out in a pipe which is connected to a geothermal production well, KMJ-14. The pipe has a 10” outside diameter and contains dry vapor at a pressure of 8 kg/cm2 and a temperature of 170 oC. Krypton-85 gas isotope (85Kr) has been injected into the pipe. Three collimated radiation detectors positioned respectively at 127, 177 and 227 m from injection point were used to obtain experimental data which represent radiotracer residence time distribution (RTD) in the pipe. The last detector at the position of 227 m did not respond, which might be due to problems in cable connections. Flow properties calculated using mean residence time (MRT) shows that the flow rate of the vapor in pipe is 10.98 m/s, much faster than fluid flow commonly found in various industrial process plants. Best fitting evaluated using dedicated software developed by IAEA expert obtained the Péclet number Pe as 223. This means that the flow of vapor of geothermal fluids in pipe is plug flow in character. The molecular diffusion coefficient is 0.45 m2/s, calculated from the axial dispersion model. (author)

  6. Preliminary characterization of a water vaporizer for resistojet applications

    Science.gov (United States)

    Morren, W. Earl

    1992-09-01

    A series of tests was conducted to explore the characteristics of a water vaporizer intended for application to resistojet propulsion systems. The objectives of these tests were to (1) observe the effect of orientation with respect to gravity on vaporizer stability, (2) characterize vaporizer efficiency and outlet conditions over a range of flow rates, and (3) measure the thrust performance of a vaporizer/resistojet thruster assembly. A laboratory model of a forced-flow, once-through water vaporizer employing a porous heat exchange medium was built and characterized over a range of flow rates and power levels of interest for application to water resistojets. In a test during which the vaporizer was rotated about a horizontal axis normal to its own axis, the outlet temperature and mass flow rate through the vaporizer remained steady. Throttlability to 30 percent of the maximum flow rate tested was demonstrated. The measured thermal efficiency of the vaporizer was near 0.9 for all tests. The water vaporizer was integrated with an engineering model multipropellant resistojet. Performance of the vaporizer/thruster assembly was measured over a narrow range of operating conditions. The maximum specific impulse measured was 234 s at a mass flow rate and specific power level (vaporizer and thruster combined) of 154 x 10(exp-6)kg/s and 6.8 MJ/kg, respectively.

  7. Atomic vapor spectroscopy in integrated photonic structures

    CERN Document Server

    Ritter, Ralf; Pernice, Wolfram; Kübler, Harald; Pfau, Tilman; Löw, Robert

    2015-01-01

    We investigate an integrated optical chip immersed in atomic vapor providing several waveguide geometries for spectroscopy applications. The narrow-band transmission through a silicon nitride waveguide and interferometer is altered when the guided light is coupled to a vapor of rubidium atoms via the evanescent tail of the waveguide mode. We use grating couplers to couple between the waveguide mode and the radiating wave, which allow for addressing arbitrary coupling positions on the chip surface. The evanescent atom-light interaction can be numerically simulated and shows excellent agreement with our experimental data. This work demonstrates a next step towards miniaturization and integration of alkali atom spectroscopy and provides a platform for further fundamental studies of complex waveguide structures.

  8. Liquid-liquid contact in vapor explosion

    International Nuclear Information System (INIS)

    The contact of two liquid materials, one of which is at a temperature substantially above the boiling point of the other, can lead to fast energy conversion and a subsequent shock wave. This phenomenon is called a vapor explosion. One method of producing intimate, liquid-liquid contact (which is known to be a necessary condition for vapor explosion) is a shock tube configuration. Such experiments in which water was impacted upon molten aluminum showed that very high pressures, even larger than the thermodynamic critical pressure, could occur. The mechanism by which such sharp pressure pulses are generated is not yet clear. The report describes experiments in which cold liquids (Freon-11, Freon-22, water, or butanol) were impacted upon various hot materials

  9. Modelling vaporous cavitation on fluid transients

    CERN Document Server

    Shu, Jian-Jun

    2014-01-01

    A comprehensive study of the problem of modelling vaporous cavitation in transmission lines is presented. The two-phase homogeneous equilibrium vaporous cavitation model which has been developed is compared with the conventional column separation model. The latter predicts unrealistically high pressure spikes because of a conflict arising from the prediction of negative cavity sizes if the pressure is not permitted to fall below the vapour pressure, or the prediction of negative absolute pressures if the cavity size remains positive. This is verified by a comparison of predictions with previously published experimental results on upstream, midstream and downstream cavitation. The new model has been extended to include frequency-dependent friction. The characteristics predicted by the frequency-dependent friction model show close correspondence with experimental data.

  10. Effect of Salt Additives to Water on the Severity of Vapor Explosions and on the Collapse of Vapor Film

    Science.gov (United States)

    Arai, Takahiro; Furuya, Masahiro

    We proposed ultra rapid solidification and atomization technique, CANOPUS (Cooling and Atomizing based on NOble Process Utilizing Steam explosion), using small-scale vapor explosions to make an amorphous metal. The CANOPUS method is suitable for rapid cooling and atomization process, which utilizing sustainable small-scale vapor explosions. In order to apply the CANOPUS method to a high melting point metal, it is necessary to make a small-scale vapor explosion occur at a high temperature of the molten metal. Small-scale experiment is conducted to develop the vapor explosion promotor in which spontaneous vapor explosion can occur at a high temperature of a molten metal. Spontaneous vapor explosion do not occur when water at 80°C is used as a coolant. However, spontaneous vapor explosion occurs when water at 80°C with salt additives is used as a coolant. Specifically, lithium chloride solution generates spontaneous vapor explosions at the highest temperature of the molten tin in the experiment. In order to clarify the triggering mechanism of the spontaneous vapor explosion when the promotor is used as a coolant, a high-temperature solid stainless steel sphere is immersed into a coolant. The interfacial temperature of the stainless steel sphere is measured, and the behavior of a vapor film around the stainless steel sphere is observed with a digital video camera. As a result, salt additives resulted in an increase of quench temperature in all salt solutions. The quenching curves of each coolant indicate that the salt additives improve the film boiling heat transfer. The improvement of the film boiling heat transfer causes an unstable formation of the vapor film and a rise of the quench temperature. It is clarified that the salt additives to water promotes a vapor film collapse. Comparing two experiments, the quench temperature of each solution is in close agreement with the upper limit of the molten tin temperature that causes spontaneous vapor explosion. This result suggests that the vapor film collapse triggers spontaneous vapor explosion.

  11. Diversion Radiometer Data for Water Vapor Direction Delay

    Directory of Open Access Journals (Sweden)

    Ahmad Khalf Aldhafari

    2013-02-01

    Full Text Available The radiometers for probing water vapor, temperature and cloud liquid water do not show the highaccuracy and stability which is needed for some applicationslike turbulent weather conditions. The Form of direction delayfrom atmospheric water vapor is a main error source ingeodetic measurements made with VLBI. A dual channelwater vapor radiometer, operating near the 22GHz watervapor line , and measuring water vapor-induced delay withgood conditions. Theory shows that water vapor directiondelay ?LV is related to a linear combination of saturation corrected sky brightness temperatures, measured the watervapor line. Sky brightness temperatures are saturationcorrectedor "linearized" using estimates of effective skytemperature made from surface temperature. A systematicmethod for reducing dual-frequency water vapor radiometerdata to water vapor path delay has been developed Coefficients are found from a regression of theoreticalbrightness temperatures versus radiosonde measured delay.Regression solutions are constrained to remove liquid watercontributions and to give the correct slope for radiometerversus radiosonde path delay.

  12. Vaporization behavior of non-stoichiometric thorium monocarbides

    International Nuclear Information System (INIS)

    Vapor pressure of non-stoichiometric ThC was determined based on the measurement of vaporization behavior of ThC/sub x/O/sub y/. First, the partial vapor pressures of ThO(g), Th(g), and CO(g) over ThC/sub x/O/sub y/ were determined. Then, after the vapor signal of ThO(g) was attenuated, the vapor pressure of Th(g) over ThC(s) was measured and the enthalpy of vaporization of Th(g) was derived. The observed change with composition of vaporization properties of ThC(s) was similar with that of UC(s) of literature. The phase boundary of the ThC + ThC/sub 2/ region was suggested to exist between ThC/sub 1.007/ and ThC/sub 1.074/ for the temperature range of 2100 to 2300K

  13. Engagement Means Everyone

    Science.gov (United States)

    Patton, Carol

    2012-01-01

    Employee engagement is not just HR's responsibility. While HR is responsible for the process of measuring and driving engagement, improving it is actually everyone's responsibility. And that means reducing the barriers to productivity to drive business performance. Training departments can play a pivotal role. Their job is to enhance curriculum or…

  14. Means on scattered compacta.

    Czech Academy of Sciences Publication Activity Database

    Banakh, T.; Bonnet, R.; Kubi?, Wieslaw

    2014-01-01

    Ro?. 2, ?. 1 (2014), s. 5-10. ISSN 2299-3231 R&D Projects: GA ?R(CZ) GAP201/12/0290 Institutional support: RVO:67985840 Keywords : scattered compact space * mean operation Subject RIV: BA - General Mathematics http://www.degruyter.com/view/j/taa.2014.2.issue-1/taa-2014-0002/taa-2014-0002.xml

  15. Meaning Negotiation as Inference

    CERN Document Server

    Burato, Elisa; Viganò, Luca

    2011-01-01

    Meaning negotiation (MN) is the general process with which agents reach an agreement about the meaning of a set of terms. Artificial Intelligence scholars have dealt with the problem of MN by means of argumentations schemes, beliefs merging and information fusion operators, and ontology alignment but the proposed approaches depend upon the number of participants. In this paper, we give a general model of MN for an arbitrary number of agents, in which each participant discusses with the others her viewpoint by exhibiting it in an actual set of constraints on the meaning of the negotiated terms. We call this presentation of individual viewpoints an angle. The agents do not aim at forming a common viewpoint but, instead, at agreeing about an acceptable common angle. We analyze separately the process of MN by two agents (\\emph{bilateral} or \\emph{pairwise} MN) and by more than two agents (\\emph{multiparty} MN), and we use game theoretic models to understand how the process develops in both cases: the models are B...

  16. The meaning of talent

    Directory of Open Access Journals (Sweden)

    Raquel Lorenzo

    2006-01-01

    Full Text Available The knowledge society gives a remarkable role to human potentialities into organizations. For this reason has emerged talent management. But it is necessary to know its meaning to put on practice programs. In this paper, the author analyzes different points of views about this topic.

  17. Chemical vapor deposition of graphene films

    International Nuclear Information System (INIS)

    Graphene films were grown on nickel films and foils using chemical vapor deposition. To date, similar growth has been reported at around 1000 deg. C using methane or ethylene as source gases. However, by using acetylene, we have achieved growth of graphene films between 650 and 700 deg. C. The electrical and optical properties, including high resolution transmission electron microscopy of these films, suggest that this technique is both viable and scalable for potential large area optoelectronic applications.

  18. Investigation of a pulse manganese vapor laser

    Energy Technology Data Exchange (ETDEWEB)

    Isaev, A.A.; Kazaryan, M.A.; Petrash, G.G.; Cherezov, V.M.

    1976-08-01

    An investigation was made of a pulse manganese vapor laser operated under self-heating conditions at a high pulse repetition frequency. The output power was determined as a function of gas-discharge conditions. The best output parameters were obtained using helium as a buffer gas: the average output power was found to be 2.1 W, the peak power was 24 kW, and the efficiency was 0.2%. (AIP)

  19. Ultraviolet-emitting gold vapor laser

    Energy Technology Data Exchange (ETDEWEB)

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

    1978-07-01

    An investigation was made of pulsed stimulated emission of ultraviolet radiation from gold vapor in discharge mixtures with helium, neon, and argon. In a discharge with neon, the average output power at the 312.2 nm wavelength was 1.2 W and the efficiency was 0.03%. At 627.8 nm, under similar excitation conditions, the average output power was 6 W and the efficiency was 0.2%.

  20. DuPont Chemical Vapor Technical Report

    International Nuclear Information System (INIS)

    DuPont Safety Resources was tasked with reviewing the current chemical vapor control practices and providing preventive recommendations on best commercial techniques to control worker exposures. The increased focus of the tank closure project to meet the 2024 Tri-Party Agreement (TPA) milestones has surfaced concerns among some CH2MHill employees and other interested parties. CH2MHill is committed to providing a safe working environment for employees and desires to safely manage the tank farm operations using appropriate control measures. To address worker concerns, CH2MHill has chartered a ''Chemical Vapors Project'' to integrate the activities of multiple CH2MHill project teams, and solicit the expertise of external resources, including an independent Industrial Hygiene expert panel, a communications consultant, and DuPont Safety Resources. Over a three-month time period, DuPont worked with CH2MHill ESH and Q, Industrial Hygiene, Engineering, and the independent expert panel to perform the assessment. The process included overview presentations, formal interviews, informal discussions, documentation review, and literature review. DuPont Safety Resources concluded that it is highly unlikely that workers in the tank farms are exposed to chemicals above established standards. Additionally, the conventional and radiological chemistry is understood, the inherent chemical hazards are known, and the risk associated with chemical vapor exposure is properly managed. The assessment highlighted management's commitment to addressing chemical vapor hazards and controlling the associated risks. Additionally, we found the Industrial Hygiene staff to be technically competent and well motivated. The tank characterization data resides in a comprehensive database containing the tank chemical compositions and relevant airborne concentrations

  1. Liquid-vapor interfaces of patchy colloids

    Science.gov (United States)

    Oleksy, A.; Teixeira, P. I. C.

    2015-01-01

    We investigate the liquid-vapor interface of a model of patchy colloids. This model consists of hard spheres decorated with short-ranged attractive sites ("patches") of different types on their surfaces. We focus on a one-component fluid with two patches of type A and nine patches of type B (2 A 9 B colloids), which has been found to exhibit reentrant liquid-vapor coexistence curves and very low-density liquid phases. We have used the density-functional theory form of Wertheim's first-order perturbation theory of association, as implemented by Yu and Wu [J. Chem. Phys. 116, 7094 (2002), 10.1063/1.1463435], to calculate the surface tension, and the density and degree of association profiles, at the liquid-vapor interface of our model. In reentrant systems, where A B bonds dominate, an unusual thickening of the interface is observed at low temperatures. Furthermore, the surface tension versus temperature curve reaches a maximum, in agreement with Bernardino and Telo da Gama's mesoscopic Landau-Safran theory [Phys. Rev. Lett. 109, 116103 (2012), 10.1103/PhysRevLett.109.116103]. If B B attractions are also present, competition between A B and B B bonds gradually restores the monotonic temperature dependence of the surface tension. Lastly, the interface is "hairy," i.e., it contains a region where the average chain length is close to that in the bulk liquid, but where the density is that of the vapor. Sufficiently strong B B attractions remove these features, and the system reverts to the behavior seen in atomic fluids.

  2. Isotope targets prepared by vapor deposition

    International Nuclear Information System (INIS)

    As the state of the art for producing thin films has developed, the parameters set by the experiments have in turn become more stringent. Often these targets must be of high purity, extremely thin, self-supporting, and of accurately determined thickness. In addition, the target material may be an expensive isotope which must be reduced to elemental form at the time of vapor deposition. Methods of producing some of these targets will be discussed with such examples as calcium, magnesium and boron

  3. Making Ceramic Fibers By Chemical Vapor

    Science.gov (United States)

    Revankar, Vithal V. S.; Hlavacek, Vladimir

    1994-01-01

    Research and development of fabrication techniques for chemical vapor deposition (CVD) of ceramic fibers presented in two reports. Fibers of SiC, TiB2, TiC, B4C, and CrB2 intended for use as reinforcements in metal-matrix composite materials. CVD offers important advantages over other processes: fibers purer and stronger and processed at temperatures below melting points of constituent materials.

  4. Numerical modeling tools for chemical vapor deposition

    Science.gov (United States)

    Jasinski, Thomas J.; Childs, Edward P.

    1992-01-01

    Development of general numerical simulation tools for chemical vapor deposition (CVD) was the objective of this study. Physical models of important CVD phenomena were developed and implemented into the commercial computational fluid dynamics software FLUENT. The resulting software can address general geometries as well as the most important phenomena occurring with CVD reactors: fluid flow patterns, temperature and chemical species distribution, gas phase and surface deposition. The physical models are documented which are available and examples are provided of CVD simulation capabilities.

  5. Comparison of MRI, CT, TCD and SPECT in patients with spongiform leukoencephalopathy after inhaling heroin vapor

    International Nuclear Information System (INIS)

    Objective: To compare the characteristics of MRI, CT, single photon emission computed tomography (SPECT) and transcranial Doppler sonography (TCD) in patients with spongiform leukoencephalopathy after inhaling heroin vapor. Methods: Seventeen patients were investigated. MRI or CT was scanned in 17 patients, SPECT in 9 patients' and TCD in 11 patients. Results: MRI or CT: Brain MRI and CT revealed extensive symmetric white matter involvement of bilateral cerebral and cerebellar hemispheres and the brainstem. The lesions, which showed no contrast enhancement, were hypodense on CT and hypointense on T1-weighted and hyperintense on T2-weighted MRI. SPECT: The regional cerebral blood flows (rCBF) of white matter involvement on bilateral cerebral and cerebellar hemispheres was reduced obviously. The rCBF of temporal lobes, parietal lobes, occipital lobes, cerebellar hemispheres, and basal ganglion was reduced in varying degrees. TCD: The systolic peak became sharpened, and end-diastolic flow velocity and mean flow velocity were reduced obviously and pulsatile index was increased markedly in patients with spongiform leukoencephalopathy after inhaling heroin vapor. Conclusion: The characteristic manifestations of MRI and CT imaging may be regarded as the main foundation of diagnosing spongiform leukoencephalopathy after inhaling heroin vapor; SPECT and TCD can help comprehend the changes of hemodynamics of cerebral vessels and the degree of cerebral ischemia in patients with spongiform leukoencephalopathy after inhaling heroin vapor

  6. Monte-Carlo simulation of complex vapor-transport systems for RIB applications

    International Nuclear Information System (INIS)

    In order to minimize decay losses of short-lived radioactive species at ISOL based RIB facilities, effusive-flow particle transit times between target and ion source must be as short as practically achievable. A Monte-Carlo code has been developed for simulating the effusive-flow of neutral particles through vapor-transport systems independent of materials of construction. The code provides average distance traveled and time information associated with the transit of individual particles through a system. It offers a cost effective and accurate means for arriving at vapor-transport system designs. In this report, the code will be described and results obtained by its use in evaluating several prototype vapor-transport systems using specular reflection, cosine and isotropic particle re-emission about the normal to the surface models following adsorption. Simulation results obtained with an isotropic distribution are in close agreement with experimental measurements of the properties of prototype vapor-transport systems fabricated at the Holifield Radioactive Ion Beam Facility

  7. Particle-size distribution in capacitor discharge vaporization of uranium dioxide

    International Nuclear Information System (INIS)

    A homogeneous nucleation-condensation growth model was developed for calculating particle-size distributions measured in capacitor discharge vaporization (CDV) experiments conducted at the Oak Ridge National Laboratory. Uranium dioxide pellets were partially vaporized in an argon environment by rapid energy deposition through capacitor discharge. This was followed by rapid expansion and subsequent condensation of the UO2 vapor. Measured primary particle-size distributions of the resulting aerosols were lognormal, with a geometric mean particle diameter of (0.014 + or - 0.002) ?m and a geometric standard deviation of 1.7 + or - 0.1. It was postulated that the expanding UO2 vapor compressed the surrounding argon as in a spherical shock tube and that the aerosol was generated by homogeneous nucleation and condensation growth in the resulting rarefaction wave. The calculated motion of the UO2-argon interface is in approximate agreement with the movies of the expansion process. The calculated particle-size distributions are in agreement with the measured distributions except at the large particle end. This agreement indicates that the small primary particles from the CDV tests resulted from homogeneous nucleation and condensation growth, as assumed in the analytical model

  8. Designing polymer surfaces via vapor deposition

    Directory of Open Access Journals (Sweden)

    Ayse Asatekin

    2010-05-01

    Full Text Available Chemical Vapor Deposition (CVD methods significantly augment the capabilities of traditional surface modification techniques for designing polymeric surfaces. In CVD polymerization, the monomer(s are delivered to the surface through the vapor phase and then undergo simultaneous polymerization and thin film formation. By eliminating the need to dissolve macromolecules, CVD enables insoluble polymers to be coated and prevents solvent damage to the substrate. Since de-wetting and surface tension effects are absent, CVD coatings conform to the geometry of the underlying substrate. Hence, CVD polymers can be readily applied to virtually any substrate: organic, inorganic, rigid, flexible, planar, three-dimensional, dense, or porous. CVD methods integrate readily with other vacuum processes used to fabricate patterned surfaces and devices. CVD film growth proceeds from the substrate up, allowing for interfacial engineering, real-time monitoring, thickness control, and the synthesis of films with graded composition. This article focuses on two CVD polymerization methods that closely translate solution chemistry to vapor deposition; initiated CVD and oxidative CVD. The basic concepts underlying these methods and the resultant advantages over other thin film coating techniques are described, along with selected applications where CVD polymers are an enabling technology.

  9. MIPAS middle atmosphere water vapor distributions

    Science.gov (United States)

    Garcia-Comas, Maya; Lopez-Puertas, Manuel; Funke, Bernd; Bermejo-Pantale, Diego; Stiller, Gabriele; Grabowski, Udo; von Clarmann, Thomas

    Water vapor is a key constituent of the middle atmosphere. It is involved in the ozone chem-istry, it is the precursor of PSCs and PMCs, and it is an infrared cooler in the stratosphere. The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) onboard Envisat observes the H2O infrared emissions with high resolution up to the mesopause. We have derived water vapor abundance from MIPAS spectra using the IMK/IAA data processor, which includes the GRANADA non-LTE algorithm. That allows for accurate H2O retrievals in the atmospheric regions where its emissions are affected by non-LTE, i.e., above 50km and particularly in the polar summer. We describe the information gained from MIPAS spectra about the non-LTE processes affecting the H2O infrared emissions, discuss its uncertainties and present MIPAS pole-to-pole distributions of water vapor retrieved from the stratosphere to the upper meso-sphere. We pay special attention to its behavior in the polar summer mesosphere, where the presence of PMCs and particular dynamical events may perturb the H2O vertical distribution. We also compare our results with those from global circulation models and other independent measurements.

  10. Biofiltration of gasoline vapor by compost media

    International Nuclear Information System (INIS)

    A compost medium was effective in biofiltering gasoline vapor. - Gasoline vapor was treated using a compost biofilter operated in upflow mode over 4 months. The gas velocity was 6 m/h, yielding an empty bed retention time (EBRT) of 10 min. Benzene, toluene, ethylbenzene and xylene (BTEX) and total petroleum hydrocarbon (TPH) removal efficiencies remained fairly stable approximately 15 days after biofilter start-up. The average removal efficiencies of TPH and BTEX were 80 and 85%, respectively, during 4 months of stable operation. Biodegradation portions of the treated TPH and BTEX were 60 and 64%, respectively. When the influent concentration of TPH was less than 7800 mg TPH/m3, approximately 50% of TPH in the gas stream was removed in the lower half of the biofilter. When the influent concentration of BTEX was less than 720 mg BTEX/m3, over 75% of BTEX in the gas stream was removed in the lower half of the biofilter. Benzene removal efficiency was the lowest among BTEX. A pressure drop could not be detected over a 1-m bed height at a gas velocity of 6 m/h after approximately 4 months of operation. Results demonstrated that BTEX in gasoline vapor could be treated effectively using a compost biofilter

  11. Combined rankine and vapor compression cycles

    Science.gov (United States)

    Radcliff, Thomas D.; Biederman, Bruce P.; Brasz, Joost J.

    2005-04-19

    An organic rankine cycle system is combined with a vapor compression cycle system with the turbine generator of the organic rankine cycle generating the power necessary to operate the motor of the refrigerant compressor. The vapor compression cycle is applied with its evaporator cooling the inlet air into a gas turbine, and the organic rankine cycle is applied to receive heat from a gas turbine exhaust to heat its boiler within one embodiment, a common condenser is used for the organic rankine cycle and the vapor compression cycle, with a common refrigerant, R-245a being circulated within both systems. In another embodiment, the turbine driven generator has a common shaft connected to the compressor to thereby eliminate the need for a separate motor to drive the compressor. In another embodiment, an organic rankine cycle system is applied to an internal combustion engine to cool the fluids thereof, and the turbo charged air is cooled first by the organic rankine cycle system and then by an air conditioner prior to passing into the intake of the engine.

  12. Liquid--liquid contact in vapor explosion

    International Nuclear Information System (INIS)

    The contact of two liquid materials, one of which is at a temperature substantially above the boiling point of the other, can lead to fast energy conversion and a subsequent shock wave. This well-known phenomenon is called a ''vapor explosion.'' One method of producing intimate, liquid--liquid contact (which is known to be a necessary condition for vapor explosion) is a shock tube configuration. Such experiments in which water was impacted upon molten aluminum showed that very high pressures, even larger than the thermodynamic critical pressure, could occur. The mechanism by which such sharp pressure pulses are generated is not yet clear. In this experiment cold liquids (Freon-11, Freon-22, water, or butanol) were impacted upon various hot materials (mineral oil, silicone oil, water, mercury, molten Wood's metal or molten salt mixture). The main conclusion from the experimental study is that hydrodynamic effects may be very significant in any shock tube analyses, especially when multiple interactions are observed. A theoretical study was performed to check the possibility of vapor film squeezing (between a drop in film boiling and a surface) as a controlling mechanism for making liquid--liquid contact. Using experimental data, the film thickness was calculated and it was found to be too thick for any conceivable film rupture mechanism. It was suggested that the coalescence is a two-stage process, in which the controlling stage depends mainly on temperature and surface properties and can be described as the ability of cold liquid to spread on a hot surface

  13. Distribution of Water Vapor in Molecular Clouds

    CERN Document Server

    Melnick, Gary J; Snell, Ronald L; Bergin, Edwin A; Hollenbach, David J; Kaufman, Michael J; Li, Di; Neufeld, David A

    2010-01-01

    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 Av < 15 mag., the ratio of H2O 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...

  14. Selective optical detection of aromatic vapors

    Science.gov (United States)

    Podgorsek, Robert P.; Franke, Hilmar

    2002-02-01

    A sensitive layer system of amorphous Teflon AF on silver has been coated on a glass substrate. With a monochromatic light source the reflectivity of the layer system as a function of the angle of incidence exhibits the surface-plasmon resonance as well as a set of leaky-mode resonances. These optical resonance phenomena are sensitive to small refractive-index changes that may be induced by diffusion of particles into the Teflon AF layer. On the basis of this effect, the aromatic vapors benzene; toluene; and o-, p-, and m-xylene have been investigated with different vapor concentrations. By selection of a distinct angle at a particular resonance, dynamic measurements can be performed. Assuming a diffusion process in accordance with Fick's law, the diffusion profile can be calculated as a function of time. As described by the Lorentz-Lorenz relation a refractive-index profile is induced that consequently interacts with the electromagnetic fields of the optical modes. With the function of the diffusion-induced refractive-index profile the shift of the resonance lines can be calculated from the measured reflectivity change as a function of time. The characteristic diffusion coefficients of the particular vapor allow for a distinction between the different types of aromate, even between the different xylenes.

  15. Water vapor distribution in protoplanetary disks

    CERN Document Server

    Du, Fujun

    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 absorption by water of Lyman alpha photons, since the Lyman alpha line dominates the UV spectrum of accreting young stars. In a fiducial model, we find that warm water vapor with temperature around 300 K is mainly distributed in a small and well-confined region in the inner disk. The inner boundary of the warm water region is where the shielding of UV field due to dust and water itself become significant. The outer boundary is where the dust temperature drops below the water condensation temperature. A more luminous central star leads to a more ...

  16. Finding organic vapors - a Monte Carlo approach

    Science.gov (United States)

    Vuollekoski, Henri; Boy, Michael; Kerminen, Veli-Matti; Kulmala, Markku

    2010-05-01

    Aerosols have an important role in regulating the climate both directly by absorbing and scattering solar radiation, as well as indirectly by acting as cloud condensation nuclei. While it is known that their net effect on radiative forcing is negative, several key aspects remain mysterious. There exist plenty of known primary sources of particles due to both natural and man-made origin - for example desert dust, volcanic activity and tire debris. On the other hand, it has been shown that the formation of secondary particles, by nucleation from precursor vapors, is a frequent, global phenomenon. However, the very earliest steps in new particle formation - nucleation and early growth by condensation - have many big question marks on them. While several studies have indicated the importance of a sufficient concentration of sulphuric acid vapor for the process, it has also been noted that this is usually not enough. Heads have therefore turned to organic vapors, which in their multitude could explain various observed characteristics of new particle formation. But alas, the vast number of organic compounds, their complex chemistry and properties that make them difficult to measure, have complicated the quantifying task. Nevertheless, evidence of organic contribution in particles of all size classes has been found. In particular, a significant organic constituent in the very finest particles suggests the presence of a high concentration of very low-volatile organic vapors. In this study, new particle formation in the boreal forest environment of Hyytiälä, Finland, is investigated in a process model. Our goal is to quantify the concentration, to find the diurnal profile and to get hints of the identity of some organic vapors taking part in new particle formation. Previous studies on the subject have relied on data analysis of the growth rate of the observed particles. However, due to the coarse nature of the methods used to calculate growth rates, this approach has its drawbacks in accuracy, the inability to find diurnal variation and the lack of size resolution. Here, we aim to shed some light onto the problem by applying an ad hoc Monte Carlo algorithm to a well established aerosol dynamical model, the University of Helsinki Multicomponent Aerosol model (UHMA). By performing a side-by-side comparison with measurement data within the algorithm, this approach has the significant advantage of decreasing the amount of manual labor. But more importantly, by basing the comparison on particle number size distribution data - a quantity that can be quite reliably measured - the accuracy of the results is good.

  17. Measurement of background gas in paraffin-coated alkali vapor cells

    CERN Document Server

    Sekiguchi, Naota

    2015-01-01

    We measured the rate of velocity-changing collisions (VCCs) between alkali atoms and background gas in buffer-gas-free anti-spin-relaxation-coated cells. The average VCC rate in paraffin-coated rubidium vapor cells prepared in this work was $1 \\times 10^{6}$ s$^{-1}$, which corresponds to $\\sim$1 mm in the mean free path of rubidium atoms. This short mean free path indicates that alkali atoms do not travel freely between the cell walls. In addition, we found that a heating process known as "ripening" increases the VCC rate, and also confirmed that ripening improves the anti-relaxation performance of the coatings.

  18. Expérimentation des écoulements diphasiques en conduites pétrolières : boucles d'essais de Boussens Two-Phase Flow Experimentation in Pipes : Test Loops At Boussens

    Directory of Open Access Journals (Sweden)

    Roux A.

    2006-11-01

    Full Text Available Les deux boucles d'essais des écoulements diphasiques pétroliers en fonctionnement à Boussens, près de Toulouse, sont présentées brièvement. Ces équipements originaux permettent d'expérimenter les écoulements d'huile et de gaz associé ou de gaz à condensat en conditions pétrolières industrielles. La première boucle, mise au point en 1976, permet d'étudier les écoulements diphasiques horizontaux ou à faibles pentes qui prédominent dans les conduites de transport (collectes et pipelines terrestres ou marins. Elle comporte une conduite d'essais diamètre 6 de longueur 120 m inclinable de ± 4° par rapport à l'horizontale. La seconde boucle, réalisée en 1981, permet d'expérimenter des écoulements polyphasiques verticaux et fortement inclinés qui prédominent dans les tubings de production de puits pétroliers et dans les risers de production. Elle comporte deux conduites d'essais diamètre 3 et 6et longueur 25 m inclinables de ± 90° par rapport à l'horizontale. The two two-phase flow test loops operating at Boussens, near Toulouse, are briefly described. This original equipment is used for experimenting flows of oil and associated gas or gas and condensate under industrial production conditions. The first loop developed in 1976 was used for analyzing two-phase flows moving horizontally or with a slight slope such as are predominantly found in pipelines (onshore or offshore gathering lines and pipelines. It consists of a test pipe 6 in diameter and 120 m long that can be inclined ± 4° from the horizontal. The second loop was built in 1981 and has been used for experimenting vertical and highly inclined multiphase flows such as the ones found in the production tubings in oil wells and in production risers. It consists of two test pipes 3and 6in diameter and 25 m long, which can be inclined ± 90° from the horizontal.

  19. Robust empirical mean Estimators

    CERN Document Server

    Lerasle, M

    2011-01-01

    We study robust estimators of the mean of a probability measure $P$, called robust empirical mean estimators. This elementary construction is then used to revisit a problem of aggregation and a problem of estimator selection, extending these methods to not necessarily bounded collections of previous estimators. We consider then the problem of robust $M$-estimation. We propose a slightly more complicated construction to handle this problem and, as examples of applications, we apply our general approach to least-squares density estimation, to density estimation with K\\"ullback loss and to a non-Gaussian, unbounded, random design and heteroscedastic regression problem. Finally, we show that our strategy can be used when the data are only assumed to be mixing.

  20. Mean Volatility Regressions

    OpenAIRE

    Lin, Lu; LI, FENG; Zhu, Lixing; Härdle, Wolfgang Karl

    2011-01-01

    Motivated by increment process modeling for two correlated random and non-random systems from a discrete-time asset pricing with both risk free asset and risky security, we propose a class of semiparametric regressions for a combination of a non-random and a random system. Unlike classical regressions, mean regression functions in the new model contain variance components and the model variables are related to latent variables, for which certain economic interpretation can be made. The motiva...

  1. Focus on Meaning

    DEFF Research Database (Denmark)

    Zhang, Chun; Wang Jingjing, Jenny

    2014-01-01

    Abstract This study examines the effect of mapping between the semantic and conceptual representation of target words ?????, and ?on Chinese (L2) vocabulary learning at a university class. Students (N=25) were the 2nd-year Chinese –major students at one university in Denmark. They were given tests recognizing new vocabulary (two-, three and four-character words) in a series of simple meaning recognition tests administered by the authors over three weeks. The test sets consist of vocabulary with ...

  2. Improvisation and meaning

    OpenAIRE

    Gilbertson, Simon

    2013-01-01

    This article presents and discusses a long-term repeated-immersion research process that explores meaning allocated to an episode of 50 seconds of music improvisation in early neurosurgical rehabilitation by a teenage boy with severe traumatic brain injury and his music therapist. The process began with the original therapy session in August 1994 and extends to the current time of writing in 2013. A diverse selection of qualitative research methods were used during a repeated immersion and en...

  3. The meaning of chains

    OpenAIRE

    Sauerland, Uli

    2009-01-01

    This thesis investigates the mechanisms applying in the interpretation of syntactic chains. The theoretical background includes a translation of syntactic forms into semantic forms and a model theoretic explication of the meaning of semantic forms. Simplicity considerations apply to all three stages of the interpretation process: syntactic derivation, translation into semantic forms, interpretation of semantic forms. Three main results are achieved. The first is that trace positions can have ...

  4. Meaning and significance of

    OpenAIRE

    Ph D Student Roman Mihaela

    2011-01-01

    The concept of "public accountability" is a challenge for political science as a new concept in this area in full debate and developement ,both in theory and practice. This paper is a theoretical approach of displaying some definitions, relevant meanings and significance odf the concept in political science. The importance of this concept is that although originally it was used as a tool to improve effectiveness and eficiency of public governance, it has gradually become a purpose it itself...

  5. What does 'regionalisation' mean?

    DEFF Research Database (Denmark)

    Hegland, Troels Jacob; Ounanian, Kristen; Raakjær, Jesper

    2012-01-01

    Regionalisation has in recent years been intensely discussed as a possible path for the future Common Fisheries Policy of the European Union. However, the motivations for moving in this direction are as varied as the perceptions of what regionalisation as a mode governance would entail in practice. To draw implications for policy, we explore these perceptions and seek, by means of interviews and a survey of participants in the Regional Advisory Councils with hands-on experience in regional coope...

  6. History, Narrative, and Meaning

    OpenAIRE

    Roberto Artigiani

    2007-01-01

    Recent developments in the natural sciences make a renewed dialogue with the humanities possible. Previously, humanists resisted transferring scientific paradigms into fields like history, fearing materialism and determinism would deprive experience of its meaning and people of their freedom. At the same time, scientists were realizing that deterministic materialism made understanding phenomena like life virtually impossible. Scientists escaped the irony of describing a nature to which they d...

  7. Mean nuclear volume

    DEFF Research Database (Denmark)

    Mogensen, O.; Sørensen, Flemming Brandt; Bichel, P.; Jakobsen, A.

    1999-01-01

    We evaluated the following nine parameters with respect to their prognostic value in females with endometrial cancer: four stereologic parameters [mean nuclear volume (MNV), nuclear volume fraction, nuclear index and mitotic index], the immunohistochemical expression of cancer antigen (CA125) and the postsurgical stage (P-stage), the malignancy grade, the depth of myometrial tumor invasion and the age of the female. Tissue was obtained from 68 consecutive endometrial cancer patients with clinica...

  8. Placebo, meaning, and health.

    Science.gov (United States)

    Barrett, Bruce; Muller, Daniel; Rakel, David; Rabago, David; Marchand, Lucille; Scheder, Joanne Caroline

    2006-01-01

    Placebos are boon and bane to medical theory and clinical practice. On the one hand, randomized controlled trials employ concealed allocations of placebo to control for effects not due to specific pharmacological mechanisms. As a result, nearly all of evidence-based medicine derives from principles and practices based on placebo. On the other hand, medical researchers and physicians have tended to ignore, minimize, or deride placebos and placebo effects, perhaps due to values emphasizing scientific understanding of mechanistic pathways. We argue that intention, expectation, culture, and meaning are central to placebo-effect phenomena and are substantive determinants of health. We introduce three dualities that are integral to placebo/meaning phenomena: body-mind, subconscious-conscious, and passive-active. These placebo-related dualities should be acknowledged, explored with research, and incorporated in theory. While we view consideration of placebo and meaning effects as essential to any adequate understanding of human health, we feel that lessons from this area of inquiry may already provide practical tools for astute clinicians. Toward this end, we list eight specific clinical actions: speak positively about treatments, provide encouragement, develop trust, provide reassurance, support relationships, respect uniqueness, explore values, and create ceremony. These clinical actions can empower patients to seek greater health and may provide a healthful sense of being cared for. PMID:16702703

  9. LE CODE ETHIQUE DE CONDUITE PROFESSIONNELLE EN KINESITHERAPIE, UN DES TROIS PILIERS D’UNE PROFESSION AUTONOME ET RECONNUE EN ROUMANIE

    OpenAIRE

    Vasile Manole; François Plas; Lacramioara Manole; Doina Marza

    2009-01-01

    kinésithérapeutes roumains, l’autonomie ne manque pas de charme. Dans l’évolution de la profession qui, depuis quatre ans a su se mettre au diapason international les plus imaginatifs et progressistes deskinésithérapeutes roumains ont toutes les chances d’émouvoir les patients et les autorités, en constituant un vrai corps social reconnu et doté d’un code éthique de conduite professionnelle.Il faudrait être sourd pour ne pas entendre les voix de ceux qui dressent l’inventaire des bienfaits de...

  10. Copper and Copper Oxide Nanoparticle Formation by Chemical Vapor Nucleation From Copper (II) Acetylacetonate

    International Nuclear Information System (INIS)

    Crystalline nanometer-size copper and copper (I) oxide particle formation was studied by thermal decomposition of copper acetylacetonate Cu(acac)2 vapor using a vertical flow reactor at ambient nitrogen pressure. The experiments were performed in the precursor vapor pressure range of Pprec = 0.06 to 44 Pa at furnace temperatures of 431.5 deg. C, 596.0 deg. C, and 705.0 deg. C. Agglomerates of primary particles were formed at Pprec0.1 Pa at all temperatures. At 431.5 deg. C the number mean size of the primary particles increased from Dp = 3.7 nm (with geometric standard deviation ?g = 1.42) to Dp = 7.2 nm (?g = 1.33) with the increasing precursor vapor particle pressure from 1.8 to 16 Pa. At 705.0 deg. C the primary particle size decreased from Dp = 24.0 nm (?g=1.57) to Dp = 7.6 nm (?g = 1.54), respectively.At furnace temperatures of 431.5 deg. C and 596.0 deg. C only crystalline copper particles were produced. At 705.0 deg. C the crystalline product of the decomposition depended on the precursor vapor pressure: copper particles were formed at Pprec>10 Pa, copper (I) oxide at Pprecleq 1 Pa, and a mixture of the metal and its oxide at intermediate vapor pressures. A kinetic restriction on copper particle growth was shown, which leads to the main role of Cu2 molecule participation in the particle formation. The formation of copper (I) oxide particles occurs due to the surface reaction of the decomposition products (mainly carbon dioxide). For the explanation of the experimental results, a model is proposed to build a semiempirical phase diagram of the precursor decomposition products

  11. Analysis of Saturn's Thermal Emission at 2.2-cm Wavelength: Spatial Distribution of Ammonia Vapor

    Science.gov (United States)

    Laraia, A. L.; Ingersoll, A. P.; Janssen, Michael A.; Gulkis, Samuel; Oyafuso, Fabiano A.; Allison, Michael D.

    2013-01-01

    This work focuses on determining the latitudinal structure of ammonia vapor in Saturn's cloud layer near 1.5 bars using the brightness temperature maps derived from the Cassini RADAR (Elachi et al., 2004) instrument, which works in a passive mode to measure thermal emission from Saturn at 2.2-cm wavelength. We perform an analysis of five brightness temperature maps that span epochs from 2005 to 2011, which are presented in a companion paper by Janssen et al. (2013a, this issue). The brightness temperature maps are representative of the spatial distribution of ammonia vapor, since ammonia gas is the only effective opacity source in Saturn's atmosphere at 2.2-cm wavelength. Relatively high brightness temperatures indicate relatively low ammonia relative humidity (RH), and vice versa. We compare the observed brightness temperatures to brightness temperatures computed using the Juno atmospheric microwave radiative transfer (JAMRT) program which includes both the means to calculate a tropospheric atmosphere model for Saturn and the means to carry out radiative transfer calculations at microwave frequencies. The reference atmosphere to which we compare has a 3x solar deep mixing ratio of ammonia (we use 1.352x10(exp -4) for the solar mixing ratio of ammonia vapor relative to H2; see Atreya, 2010) and is fully saturated above its cloud base. The maps are comprised of residual brightness temperatures-observed brightness temperature minus the model brightness temperature of the saturated atmosphere.

  12. Acoustic detection of the collapse of a sodium vapor bubble in an infinite sea of sodium

    International Nuclear Information System (INIS)

    A discussion of the problem of sodium vapor bubble collapse is presented. The physics of vapor collapse is presented in light of the work by Peppler et al. Theoretical estimates of the sound source level based on the work by Rayleigh and Judd are compared to an approximate pressure-volume work approach and recent experimental observations. Reactor ambient noise and transmission loss considerations are presented in regard to their impact on this detection problem. A methodology is proposed which considers the importance of the sound source level, ambient noise, transmission loss and a detection threshold and provides a means by which the feasibility of sodium vapor bubble collapse detection in an operating LMFBR may be assessed. The interrelationships between the detection threshold and the probability of detection and false alarm are discussed and applied to a standard acoustic square law detection system. This analysis clearly illustrates that the feasibility of such a detection system is strongly dependent on the knowledge of sound source levels, ambient noise levels and the transmission loss between the source and receiver. Furthermore, requirements of a high degree of probability of detection and a low probability of false alarm were found to require a high signal to noise ratio for a single sensor system but that the probability of false alarm requirement could be relaxed for systems multiple independent sensors. Finally, the need for additional experimental and theoretical information is presented in terms of sound source levels, ambient noise and a means for determining transmission loss

  13. Contribution of water vapor to observational estimates of longwave cloud radiative forcing

    Science.gov (United States)

    Sohn, Byung-Ju; Bennartz, Ralf

    2008-10-01

    It has been long recognized that cloud-free regions are typically associated with drier air, whereas cloudy regions typically are associated with more moisture. Using Advanced Microwave Scanning Radiometer (AMSR-E) passive microwave observations, we estimated the bias between water vapor path (WVP) of clear-sky and all-sky conditions. Furthermore, we assessed the impact of these biases on longwave cloud radiative forcing (CRF). Results indicate that, in a zonal mean sense, the difference between all-sky and clear-sky WVP estimates is around 2 mm, with highest values in the midlatitudes summer, where differences up to 7 mm occur. The corresponding CRF change forced by these WVP changes is about 2 W m-2 in a zonal mean sense. Highest values occur in the midlatitudes of the northern hemisphere in which a magnitude up to 6 W m-2 is shown. Over the convectively active regions, the WVP contributed CRF appears to be smaller than 5 W m-2, substantially smaller than the CRF contributed by upper tropospheric water vapor only, suggesting that a significant portion of satellite-estimated CRF over the tropics is contributed by the redistribution of water vapor associated with convection development.

  14. The meaning of relativity

    CERN Document Server

    Einstein, Albert

    1955-01-01

    In 1921, five years after the appearance of his comprehensive paper on general relativity and twelve years before he left Europe permanently to join the Institute for Advanced Study, Albert Einstein visited Princeton University, where he delivered the Stafford Little Lectures for that year. These four lectures constituted an overview of his then-controversial theory of relativity. Princeton University Press made the lectures available under the title The Meaning of Relativity, the first book by Einstein to be produced by an American publisher. As subsequent editions were brought out by the Pr

  15. Music, memory and meaning

    OpenAIRE

    Fair, Laura

    2012-01-01

    I his paper examines the music and career of Siti binti Saadi, a famous taarab musician who performed in Zanzibar during the 1920s and 1930s. Relying on four distinctive types of evidence: her recorded music, written documentation produced in East Africa, interviews with men and women who heard her perform and records of company executives I compare perspectives regarding the source of power and authority attributed to her voice as well as the meaning of her music. Siti binti Saadi was the fi...

  16. The Meaning of Freedom

    Directory of Open Access Journals (Sweden)

    Luis Eduardo Hoyos

    2009-12-01

    Full Text Available In the article it is pretended to prepare the conceptual field for the correct use of the attribution of freedom. It is defended the importance to consider the complementarity of freedom of action and freedom of the will and it is argued for a non-metaphysical conception of adscription of freedom. The adequate use of the attribution of freedom is social and normative. This means additionally that the freedom is not a presupposition of the moral responsibility and the authorship, but on the contrary the moral responsibility and the authorship are presuppositions of the attribution of freedom.

  17. Meaning construction in remembering

    DEFF Research Database (Denmark)

    Wagoner, Brady

    2011-01-01

    F.C. Bartlett and L.S.Vygotsky were two seminal figures in the psychological study of remembering. Both emphasized the role of meaning and imagination in this process. Bartlett did this by showing the systematic and holistic changes that ensue when cultural material is repeatedly reproduced outside of the group to which it belongs. Vygotsky, on the other hand, attended to the ways in which we construct meaningful ?signs? as artificial memory aids to solve memory problems that go beyond our natur...

  18. Meaning in Matter

    DEFF Research Database (Denmark)

    Brix, Anders

    2013-01-01

    When addressing present-day challenges, design discourse put faith mainly in design understood as a problem-solving activity, pertaining to innovation on functional, systems and technological level. The aesthetically founded fields, e.g. craft-based design, on the other hand, do not seem to play any significant role in the larger scheme of strategic thinking. Thus, design as an art-form runs in the undercurrent of 'real' meaning, sometimes applauded as high fashion, but mainly framed as an exces...

  19. Mean life of klystrons

    International Nuclear Information System (INIS)

    It would be useful to have the best possible estimate of this mean life-time of our new klystrons based on the most recent, available operating experience. A simple formula is given for this best estimate, based on the maximum likelihood method. This method also provides an indication of the reliability of the estimated lifetime. The results given here apply uniquely to a uniform klystron population for which we can assume that deaths occur randomly, and independently of the previous history (operating time) of any one klystron

  20. History, Narrative, and Meaning

    Directory of Open Access Journals (Sweden)

    Roberto Artigiani

    2007-08-01

    Full Text Available Recent developments in the natural sciences make a renewed dialogue with the humanities possible. Previously, humanists resisted transferring scientific paradigms into fields like history, fearing materialism and determinism would deprive experience of its meaning and people of their freedom. At the same time, scientists were realizing that deterministic materialism made understanding phenomena like life virtually impossible. Scientists escaped the irony of describing a nature to which they did not belong by also discovering that their knowledge can never be complete and that descriptions of nature at the subatomic level were essentially random. These developments, as Monod said, weakened the “Modern” paradigm sufficiently to make life scientifically possible. To understand how life might actually exist, however, scientists had to move beyond laments about observations losing information and concentrate on how nature creates information. Nature creates information in the process of reducing thermodynamic gradients and stores created information in self-organized systems. Nature thus becomes historical, for it is defined by qualitative changes accumulating over time because of unpredictable contingencies. This paper will explore the possibility that the patterned processes by which nature changes apply in the human realm, where interactions can change people and created information can be stored in self-organized societies. Values, Ethics and Morals (VEMs are the qualitatively new information stored in social systems. VEMs script the actions structuring societies, demonstrating there is meaning in history and solving the problem of how sequences of events –“chronicles”–become narratives. Moreover, when societies compete, their system-structuring information is tested in the same way natural selection tests DNA. Thus, the succession of social systems suggests there is a meaning of history. The meaning of history need be no more transcendental or intended than Darwinian evolution. But if organs and traits can have biological value without implying design, socially constructed attributes like morality, consciousness, and freedom can be valued without supposing history has an ultimate or eternal purpose. Aspiring to show how the cacophony of historical events becomes a cosmos, a “well-ordered” context in which changes become meaningful, this sketch suggests a new understanding of nature may provide a basis for ethics.