Experimental study of ultrasonic characteristics in air-water bubbly flows

Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.In the oil industry there is a need to determine the dispersed phase holdup in multiphase flows using noninvasive, fast responding techniques; ultrasonic techniques apparently can fulfill these requirements. In this regard, the proposed paper analyzes the ultrasonic signals obtained through vertical, upward air-water flows in the zero to 14% void fraction range. Initially, the experimental apparatus and the flow patterns observed are discussed. Next follows a discussion of the ultrasonic signals characteristics and the trends in the transit time and attenuation. A new transit time definition is proposed that could be used for the characterization of two-phase flows.cs201

Focal chromosomal copy number aberrations in cancer-Needles in a genome haystack

AbstractThe extent of focal chromosomal copy number aberrations (CNAs) in cancer has been uncovered through technical innovations, and this discovery has been critical for the identification of new cancer driver genes in genomics projects such as TCGA and ICGC. Unlike constitutive copy number variations (CNVs), focal CNAs are the result of many selection events during the evolution of cancer genomes. Therefore, it is possible that a single gene in a focal CNA gives the tumor a selective growth advantage. This concept has been instrumental in the discovery of new cancer driver genes. However, focal CNAs lack a consensus definition; therefore, we propose one based on pragmatic considerations. We also describe different strategies to identify focal CNAs and procedures to distinguish them from large CNAs and CNVs

Application Of The Ultrasonic Technique For The Measurement Of The Dispersed Phases Concentrations In Three-phase Oil-continuous Mixtures

This paper examines the possibility of eliminating or diminishing the need for mixing and separation in multiphase flow metering (MFM) systems by means of the ultrasonic technique. First, a configuration of a complete MFM system using the ultrasonic is proposed and thoroughly discussed. Next, visual data and ultrasonic data in oil-continuous two- and three-phase mixtures in 54-mm diameter acrylic pipes are presented to support the proposed use to the ultrasonic technique. USP mineral oil (white oil) and 80-600 μm glass beads were used to simulate the petroleum and sand contents, respectively. Tap water was used to simulate the brine in multiphase flows. The ultrasonic data are then carefully analyzed in order to obtain the dispersed phases concentrations from the ultrasonic signals. © BHR Group 2012.185198Gold, R.C., Miller, J.S., Priddy, W.J., (1991) Measurement of Multiphase Well Fluids by Positive Displacement Meter, , BP Intl. Ltd. Offshore Europe, 3-6 September Aberdeen, United KingdomGoncalves, J.L., Paiva, T.A., Abud Jr., J.R., Carvalho, R.D.M., Venturini, O.J., Development of a Multiphase Flow Metering Procedure Based on the Ultrasonic Technique 15th International Conference on Multiphase Production Technology. 2011, , Cannes, France: BHR Group LimitedCorneliussen, S., (2005) Handbook of Multiphase Flow Metering, , Norwegian Society for Oil and Gas Measurement (NFOGM) and The Norwegian Society of Chartered Technical and Scientific Professionals (TEKNA). ISBN 82-91341-89-3Babelli, I.M.M., In search of an ideal multiphase flow meter for the oil industry (2001) The Arabian Journal for Science and Engineering, 27 (2 B), pp. 113-126Falcone, G., Hewitt, G.F., Alimonti, C., Harrison, B., Multiphase Flow Metering: Current Trends and Future Developments SPE 2002 Annual Technical Conference and Exhibition, 30 September-3 October 2001. New OrleansKouba, G.E., Shoham, O., Shirazi, S., Design and performance of gas liquid cylindrical cyclone separators BHR Group 7th International Conference on Multiphase 95, 1995Scheers, L., Multiphase Flow Metering: On its way from nursing to mature technology Hydrocarbon Production Accounting Workshop. 2008. Moscow, Russia(2004) Micro Motion-Inc White Paper: Explaining How Two-phase Flow Affects Mass Flowmeters, , Emerson Process Management. Boulder, Colorado, USA(2012) Catalog Multiphase Flow Meter 50 Series, , http://www.agarcorp.com/Literature/MPFM50.html, Solutions, A.C.P.M.C., 01(2012) Catalog Multiphase Metering Systems (Remms). Red Eye 2G Water-Cut Meter, , http://www.ep-solutions.com/solutions/EP/Red_Eye_, Weatherford I. Ltd. janCai, S., Toral, H., Experience in field tuning and operation of a multiphase meter based on neural net characterization of flow conditions FLOMEKO 2004. 2004: Gulin, China(2006) Ultrasonic Transducers Technical Notes, , Panametrics' Notes. Olympus, NTanahashi, E.I., Paiva, T.A., Grangeiro, F.A., Carvalho, R.D.M., Venturini, O.J., Bannwart, A.C., Bizotto, V.C., Application of the Ultrasonic technique for monitoring intermittent liquid-gas flows and liquid-solid flows (2010) 7th North American Conference on Multiphase Technology (MPNA 2010)Carvalho, R.D.M., Bannwart, A.C., The Use of the Ultrasonic Technique for the Study and Online Monitoring of Multiphase Flows (2010) Advances in Multiphase Flow and Heat Transfer, pp. 144-177. , D.M. L. Cheng, Editor. Bentham Science PublishersCarvalho, R.D.M., Venturini, O.J., Tanahashi, E.I., Neves Jr., F., Franca, F.A., Application of the Ultrasonic Technique for the Study of the Structure of Air-Water Bubbly Flows (2009) Experimental Thermal and Fluid Science, 33 (7), pp. 1065-1086Corneliussen, S., (2005) Excel File from Handbook of Multiphase Flow Metering, , www.nfogm.no, The Norwegian Society of Chartered Technical and Scientific Professionals (TEKNA), ISBN 82-91341-89-3 Ja

Application Of The Ultrasonic Technique For Monitoring Intermittent Liquid-gas And Liquid-solid Flows

Acoustic data are presented for horizontal intermittent slug flows of air-water mixtures and vertical flows of sand-water suspensions. For the suspensions, glass beads were used to simulate the solid content. The ultrasonic apparatus consisted of one pulse-echo transducer and three receivers. For the intermittent flows, the ultrasonic apparatus was used together with simultaneous high-speed filming. Data were then obtained for the acoustic attenuation and transit time. Variations in these parameters as a function of solid concentration were compared with data in the literature. For the intermittent flows, the bubble / liquid slug transitions were detected using the ultrasonic data. It was then possible to calculate parameters related to the flow structure. © BHR Group 2010.125139Van Hout, R., Barnea, D., Shemer, L., Evolution of statistical parameters of gas-liquid slug flow along vertical pipes (2001) Int. Journal Multiphase Flow, 27, pp. 1579-1602Taitel, Y., Barnea, D., A consistent approach for calculating pressure drop inclined slug flow (1990) Chem. Engineering Science, 45 (5), pp. 1199-1206Carvalho, R.D.M., Venturini, O.J., Tanahashi, E.I., Neves Jr., F., Franća, F.A., Application of the ultrasonic technique for the study of the structure of air-water bubbly flows (2009) Experimental Thermal and Fluid Science, 33, pp. 1065-1086Dukler, A., Hubbard, M., A model for gas-liquid slug flow in horizontal and near horizontal tubes (1975) Industrial & Engineering Chemistry Fundamentals, 14 (4), pp. 337-347Benjamin, T.B., Gravity currents and related phenomena (1968) Journal of Fluid Mechanics, 31 (2), pp. 209-248Kytömaa, H.K., Theory of sound propagation in suspensions: A guide to particle size and concentration characterization (1995) Powder Technology, 82, pp. 115-121Ulrick, R.J., A sound velocity for determining the compressibility of finely divided substances (1947) Journal of Applied Physics, 18, pp. 983-987Soong, Y., Gamwa, I.K., Blackwell, A.G., Schehl, R.R., Zarochak, M.F., Measurements of solids concentration in a three-phase reactor by an ultrasonic technique (1995) The Chemical Engineering Journal, 60, pp. 161-167Stolojanu, V., Prakash, A., Hydrodynamic measurement in a slurry bubble column using ultrasonic techniques (1997) Chemical Engineering Science, 52, pp. 4225-4230Zheng, Y., Ultrasonic measurement for two/three-phase flow detection (2003) The Canadian Journal of Chemical Engineering, 81, pp. 268-27

Chromosomal signatures of a subset of high-grade premalignant cervical lesions closely resemble invasive carcinomas

Cervical cancer develops from precancerous high-grade cervical intraepithelial neoplasia (CIN) harboring a transforming infection with high-risk human papillomavirus, which is characterized by p1

Gyrodactylus pictae n. sp (Monogenea: Gyrodactylidae) from the Trinidadian swamp guppy Poecilia picta Regan, with a discussion on species of Gyrodactylus von Nordmann, 1832 and their poeciliid hosts

Gyrodactylus pictae n. sp. is recorded from Poecilia picta in heterospecific shoals with the guppy P.␣reticulata in Northern Trinidad. G. pictae is morphologically similar to G. turnbulli Harris, 1986, but the hamuli and marginal hooks are slightly smaller and more gracile. The toe and the point of the marginal hook have a distinctly different shape, providing the best morphological characters for distinguishing the two species. The rDNA ITS1 and ITS2 sequences differ from those of G. turnbulli (the closest relative) by >5, suggesting that these two taxa are not sibling species. The origin of the two species on poeciliids of the subgenus Micropoecilia is discussed, and it is suggested that this may represent a case of host–parasite co-evolution