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Sample records for nemo phase-2 tower

  1. PORFIDO on the NEMO Phase 2 tower

    Energy Technology Data Exchange (ETDEWEB)

    Ciaffoni, Orlando; Cordelli, Marco; Habel, Roberto; Martini, Agnese; Trasatti, Luciano [INFN-Laboratori Nazionali di Frascati, Via E. Fermi 40, I-00044 Frascati (RM) (Italy)

    2014-11-18

    We have designed and built an underwater measurement system, PORFIDO (Physical Oceanography by RFID Outreach) to gather oceanographic data from the Optical Modules of a neutrino telescope with a minimum of disturbance to the main installation. PORFIDO is composed of a sensor glued to the outside of an Optical Module, in contact with seawater, and of a reader placed inside the sphere, facing the sensor. Data are transmitted to the reader through the glass by RFID and to shore in real time for periods of years. The sensor gathers power from the radio frequency, thus eliminating the need for batteries or connectors through the glass. We have deployed four PORFIDO probes measuring temperatures with the NEMO-KM3Net-Italy Phase 2 tower in april 2013. The four probes are operative and are transmitting temperature data from 3500 m depth.

  2. PORFIDO on the NEMO Phase 2 tower

    International Nuclear Information System (INIS)

    Ciaffoni, Orlando; Cordelli, Marco; Habel, Roberto; Martini, Agnese; Trasatti, Luciano

    2014-01-01

    We have designed and built an underwater measurement system, PORFIDO (Physical Oceanography by RFID Outreach) to gather oceanographic data from the Optical Modules of a neutrino telescope with a minimum of disturbance to the main installation. PORFIDO is composed of a sensor glued to the outside of an Optical Module, in contact with seawater, and of a reader placed inside the sphere, facing the sensor. Data are transmitted to the reader through the glass by RFID and to shore in real time for periods of years. The sensor gathers power from the radio frequency, thus eliminating the need for batteries or connectors through the glass. We have deployed four PORFIDO probes measuring temperatures with the NEMO-KM3Net-Italy Phase 2 tower in april 2013. The four probes are operative and are transmitting temperature data from 3500 m depth

  3. Long term monitoring of the optical background in the Capo Passero deep-sea site with the NEMO tower prototype

    International Nuclear Information System (INIS)

    Adrian-Martinez, S.; Ardid, M.; Llorens Alvarez, C.D.; Saldana, M.; Aiello, S.; Giordano, V.; Leonora, E.; Longhitano, F.; Randazzo, N.; Sipala, V.; Ventura, C.; Ameli, F.; Biagioni, A.; De Bonis, G.; Fermani, P.; Lonardo, A.; Nicolau, C.A.; Simeone, F.; Vicini, P.; Anghinolfi, M.; Hugon, C.; Musico, P.; Orzelli, A.; Sanguineti, M.; Barbarino, G.; Barbato, F.C.T.; De Rosa, G.; Di Capua, F.; Garufi, F.; Vivolo, D.; Barbarito, E.; Beverini, N.; Calamai, M.; Maccioni, E.; Marinelli, A.; Terreni, G.; Biagi, S.; Cacopardo, G.; Cali, C.; Caruso, F.; Cocimano, R.; Coniglione, R.; Costa, M.; Cuttone, G.; D'Amato, C.; De Luca, V.; Distefano, C.; Gmerk, A.; Grasso, R.; Imbesi, M.; Kulikovskiy, V.; Larosa, G.; Lattuada, D.; Leismueller, K.P.; Litrico, P.; Migneco, E.; Miraglia, A.; Musumeci, M.; Orlando, A.; Papaleo, R.; Pulvirenti, S.; Riccobene, G.; Rovelli, A.; Sapienza, P.; Sciacca, V.; Speziale, F.; Spitaleri, A.; Trovato, A.; Viola, S.; Bouhadef, B.; Flaminio, V.; Raffaelli, F.; Bozza, C.; Grella, G.; Stellacci, S.M.; Calvo, D.; Real, D.; Capone, A.; Masullo, R.; Perrina, C.; Ceres, A.; Circella, M.; Mongelli, M.; Sgura, I.; Chiarusi, T.; D'Amico, A.; Deniskina, N.; Migliozzi, P.; Mollo, C.M.; Enzenhoefer, A.; Lahmann, R.; Ferrara, G.; Fusco, L.A.; Margiotta, A.; Pellegrino, C.; Spurio, M.; Lo Presti, D.; Pugliatti, C.; Martini, A.; Trasatti, L.; Morganti, M.; Pellegriti, M.G.; Piattelli, P.; Taiuti, M.

    2016-01-01

    The NEMO Phase-2 tower is the first detector which was operated underwater for more than 1 year at the ''record'' depth of 3500 m. It was designed and built within the framework of the NEMO (NEutrino Mediterranean Observatory) project. The 380 m high tower was successfully installed in March 2013 80 km offshore Capo Passero (Italy). This is the first prototype operated on the site where the Italian node of the KM3NeT neutrino telescope will be built. The installation and operation of the NEMO Phase-2 tower has proven the functionality of the infrastructure and the operability at 3500 m depth. A more than 1 year long monitoring of the deep water characteristics of the site has been also provided. In this paper the infrastructure and the tower structure and instrumentation are described. The results of long term optical background measurements are presented. The rates show stable and low baseline values, compatible with the contribution of 40 K light emission, with a small percentage of light bursts due to bioluminescence. All these features confirm the stability and good optical properties of the site. (orig.)

  4. Long term monitoring of the optical background in the Capo Passero deep-sea site with the NEMO tower prototype

    Energy Technology Data Exchange (ETDEWEB)

    Adrian-Martinez, S.; Ardid, M.; Llorens Alvarez, C.D.; Saldana, M. [Universitat Politecnica de Valencia, Instituto de Investigacion para la Gestion Integrada de las Zonas Costeras, Gandia (Spain); Aiello, S.; Giordano, V.; Leonora, E.; Longhitano, F.; Randazzo, N.; Sipala, V.; Ventura, C. [INFN Sezione Catania, Catania (Italy); Ameli, F.; Biagioni, A.; De Bonis, G.; Fermani, P.; Lonardo, A.; Nicolau, C.A.; Simeone, F.; Vicini, P. [INFN Sezione Roma, Rome (Italy); Anghinolfi, M.; Hugon, C.; Musico, P.; Orzelli, A.; Sanguineti, M. [INFN Sezione Genova, Genoa (Italy); Barbarino, G.; Barbato, F.C.T.; De Rosa, G.; Di Capua, F.; Garufi, F.; Vivolo, D. [INFN Sezione Napoli, Naples (Italy); Dipartimento di Scienze Fisiche Universita di Napoli, Naples (Italy); Barbarito, E. [INFN Sezione Bari, Bari (Italy); Dipartimento Interateneo di Fisica Universita di Bari, Bari (Italy); Beverini, N.; Calamai, M.; Maccioni, E.; Marinelli, A.; Terreni, G. [INFN Sezione Pisa, Polo Fibonacci, Pisa (Italy); Dipartimento di Fisica Universita di Pisa, Polo Fibonacci, Pisa (Italy); Biagi, S.; Cacopardo, G.; Cali, C.; Caruso, F.; Cocimano, R.; Coniglione, R.; Costa, M.; Cuttone, G.; D' Amato, C.; De Luca, V.; Distefano, C.; Gmerk, A.; Grasso, R.; Imbesi, M.; Kulikovskiy, V.; Larosa, G.; Lattuada, D.; Leismueller, K.P.; Litrico, P.; Migneco, E.; Miraglia, A.; Musumeci, M.; Orlando, A.; Papaleo, R.; Pulvirenti, S.; Riccobene, G.; Rovelli, A.; Sapienza, P.; Sciacca, V.; Speziale, F.; Spitaleri, A.; Trovato, A.; Viola, S. [INFN Laboratori Nazionali del Sud, Catania (Italy); Bouhadef, B.; Flaminio, V.; Raffaelli, F. [INFN Sezione Pisa, Polo Fibonacci, Pisa (Italy); Bozza, C.; Grella, G.; Stellacci, S.M. [INFN Gruppo Collegato di Salerno, Fisciano (Italy); Dipartimento di Fisica Universita di Salerno, Fisciano (Italy); Calvo, D.; Real, D. [CSIC-Universitat de Valencia, IFIC-Instituto de Fisica Corpuscular, Valencia (Spain); Capone, A.; Masullo, R.; Perrina, C. [INFN Sezione Roma, Rome (Italy); Dipartimento di Fisica Universita ' ' Sapienza' ' , Rome (Italy); Ceres, A.; Circella, M.; Mongelli, M.; Sgura, I. [INFN Sezione Bari, Bari (Italy); Chiarusi, T. [INFN Sezione Bologna, Bologna (Italy); D' Amico, A. [INFN Laboratori Nazionali del Sud, Catania (Italy); Nikhef, Science Park, Amsterdam (Netherlands); Deniskina, N.; Migliozzi, P.; Mollo, C.M. [INFN Sezione Napoli, Naples (Italy); Enzenhoefer, A.; Lahmann, R. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Erlangen Centre for Astroparticle Physics, Erlangen (Germany); Ferrara, G. [INFN Laboratori Nazionali del Sud, Catania (Italy); Dipartimento di Fisica e Astronomia Universita di Catania, Catania (Italy); Fusco, L.A.; Margiotta, A.; Pellegrino, C.; Spurio, M. [INFN Sezione Bologna, Bologna (Italy); Dipartimento di Fisica ed Astronomia Universita di Bologna, Bologna (Italy); Lo Presti, D.; Pugliatti, C. [INFN Sezione Catania, Catania (Italy); Dipartimento di Fisica e Astronomia Universita di Catania, Catania (Italy); Martini, A.; Trasatti, L. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Morganti, M. [INFN Sezione Pisa, Polo Fibonacci, Pisa (Italy); Accademia Navale di Livorno, Livorno (Italy); Pellegriti, M.G. [INFN Laboratori Nazionali del Sud, Catania (IT); Piattelli, P. [INFN Laboratori Nazionali del Sud, Catania (IT); Taiuti, M. [INFN Sezione Genova, Genoa (IT); Dipartimento di Fisica Universita di Genova, Genoa (IT)

    2016-02-15

    The NEMO Phase-2 tower is the first detector which was operated underwater for more than 1 year at the ''record'' depth of 3500 m. It was designed and built within the framework of the NEMO (NEutrino Mediterranean Observatory) project. The 380 m high tower was successfully installed in March 2013 80 km offshore Capo Passero (Italy). This is the first prototype operated on the site where the Italian node of the KM3NeT neutrino telescope will be built. The installation and operation of the NEMO Phase-2 tower has proven the functionality of the infrastructure and the operability at 3500 m depth. A more than 1 year long monitoring of the deep water characteristics of the site has been also provided. In this paper the infrastructure and the tower structure and instrumentation are described. The results of long term optical background measurements are presented. The rates show stable and low baseline values, compatible with the contribution of {sup 40}K light emission, with a small percentage of light bursts due to bioluminescence. All these features confirm the stability and good optical properties of the site. (orig.)

  5. Design and assembly of the optical modules for phase-2 of the NEMO project

    Energy Technology Data Exchange (ETDEWEB)

    Leonora, E., E-mail: emanuele.leonora@ct.infn.it; Aiello, S.

    2013-10-11

    The NEMO collaboration team has undertaken a Phase-2 project, which aims at the realization and installation of a new infrastructure at the Capo Passero (Italy) deep-sea site at a depth of 3500 m. With this objective in mind, a fully equipped tower with 8-storey hosting two optical modules at each end is under construction. Following a well established procedure, 32 optical modules have been assembled. The optical module consists of a large area photomultiplier tube enclosed in a pressure resistant glass sphere with a diameter of 13 in. The photomultiplier is a R7081 type, produced by Hamamatsu, with a photocathode area with a diameter of 10 in. and 10 dynodes. Mechanical and optical contacts between the front of the photomultiplier tube and the glass surface are ensured by an optical bi-component silicone gel. A mu-metal cage is used to shield the photomultiplier against the influence of the Earth's magnetic field.

  6. KM3NeT tower data acquisition and data transport electronics

    Science.gov (United States)

    Nicolau, C. A.; Ameli, F.; Biagioni, A.; Capone, A.; Frezza, O.; Lonardo, A.; Masullo, R.; Mollo, C. M.; Orlando, A.; Simeone, F.; Vicini, P.

    2016-04-01

    In the framework of the KM3Net European project, the production stage of a large volume underwater neutrino telescope has started. The forthcoming installation includes 8 towers and 24 strings, that will be installed 100 km off-shore Capo Passero (Italy) at 3500 m depth. The KM3NeT tower, whose layout is strongly based on the NEMO Phase-2 prototype tower deployed in March 2013, has been re-engineered and partially re-designed in order to optimize production costs, power consumption, and usability. This contribution gives a description of the main electronics, including front-end, data transport and clock distribution system, of the KM3NeT tower detection unit.

  7. NEMO-SMO acoustic array: A deep-sea test of a novel acoustic positioning system for a km3-scale underwater neutrino telescope

    Science.gov (United States)

    Viola, S.; Ardid, M.; Bertin, V.; Enzenhöfer, A.; Keller, P.; Lahmann, R.; Larosa, G.; Llorens, C. D.; NEMO Collaboration; SMO Collaboration

    2013-10-01

    Within the activities of the NEMO project, the installation of a 8-floors tower (NEMO-Phase II) at a depth of 3500 m is foreseen in 2012. The tower will be installed about 80 km off-shore Capo Passero, in Sicily. On board the NEMO tower, an array of 18 acoustic sensors will be installed, permitting acoustic detection of biological sources, studies for acoustic neutrino detection and primarily acoustic positioning of the underwater structures. For the latter purpose, the sensors register acoustic signals emitted by five acoustic beacons anchored on the sea-floor. The data acquisition system of the acoustic sensors is fully integrated with the detector data transport system and is based on an “all data to shore” philosophy. Signals coming from hydrophones are continuously sampled underwater at 192 kHz/24 bit and transmitted to shore through an electro-optical cable for real-time analysis. A novel technology for underwater GPS time-stamping of data has been implemented and tested. The operation of the acoustic array will permit long-term test of sensors and electronics technologies that are proposed for the acoustic positioning system of KM3NeT.

  8. KM3NeT tower data acquisition and data transport electronics

    Directory of Open Access Journals (Sweden)

    Nicolau C.A.

    2016-01-01

    Full Text Available In the framework of the KM3Net European project, the production stage of a large volume underwater neutrino telescope has started. The forthcoming installation includes 8 towers and 24 strings, that will be installed 100 km off-shore Capo Passero (Italy at 3500 m depth. The KM3NeT tower, whose layout is strongly based on the NEMO Phase-2 prototype tower deployed in March 2013, has been re-engineered and partially re-designed in order to optimize production costs, power consumption, and usability. This contribution gives a description of the main electronics, including front-end, data transport and clock distribution system, of the KM3NeT tower detection unit.

  9. Atmospheric muons in the NEMO Phase 1 detector at the Catania test site

    International Nuclear Information System (INIS)

    Margiotta, Annarita

    2006-01-01

    The NEMO Collaboration is involved in a long term R and D activity towards the construction of a km 3 telescope in the Mediterranean sea. It has dedicated special efforts in the development of technologies for a km 3 detector and in the search, characterization and monitoring of a deep sea site adequate for the installation of the Mediterranean km 3 . Now the NEMO Collaboration is involved in the Phase 1 of the project, planning to install a fully equipped deep-sea facility to test prototypes and develop new technologies for the detector. A full Monte Carlo simulation has been performed to analyse the response of a reduced-size detector to the passage of atmospheric muons. Preliminary steps of the simulation are presented in this work

  10. Advanced energy systems and technologies (NEMO 2). Final report 1993-1998

    Energy Technology Data Exchange (ETDEWEB)

    Lund, P.; Konttinen, P. [eds.

    1998-12-31

    NEMO2 has been the major Finnish energy research programme on advanced energy systems and technologies during 1993-1998. The main objective of the programme has been to support industrial technology development but also to increase the utilisation of wind and solar energy in Finland. The main technology fields covered are wind and solar energy. In addition, the programme has supported projects on energy storage and other small-scale energy technologies such as fuel cells that support the main technology fields chosen. NEMO2 is one of the energy research programmes of the Technology Development Centre of Finland (TEKES). The total R and D funding over the whole programme period was FIM 130 million (ECU 22 million). The public funding of the total programme costs has been 43 %. The industrial participation has been strong. International co-operation has been an important aspect in NEMO2: the programme has stimulated 24 EU-projects and participation in several IEA co-operative tasks. International funding adds nearly 20 % to the NEMO2 R and D funding. (orig.)

  11. Advanced energy systems and technologies (NEMO 2). Final report 1993-1998

    International Nuclear Information System (INIS)

    Lund, P.; Konttinen, P.

    1998-01-01

    NEMO2 has been the major Finnish energy research programme on advanced energy systems and technologies during 1993-1998. The main objective of the programme has been to support industrial technology development but also to increase the utilisation of wind and solar energy in Finland. The main technology fields covered are wind and solar energy. In addition, the programme has supported projects on energy storage and other small-scale energy technologies such as fuel cells that support the main technology fields chosen. NEMO2 is one of the energy research programmes of the Technology Development Centre of Finland (TEKES). The total R and D funding over the whole programme period was FIM 130 million (ECU 22 million). The public funding of the total programme costs has been 43 %. The industrial participation has been strong. International co-operation has been an important aspect in NEMO2: the programme has stimulated 24 EU-projects and participation in several IEA co-operative tasks. International funding adds nearly 20 % to the NEMO2 R and D funding. (orig.)

  12. Study of the background neutron and gamma components of the ββ(0ν) decay in the NEMO2 prototype detector. Consequences for the NEMO3 detector

    International Nuclear Information System (INIS)

    Marquet, Christine

    1999-01-01

    Neutrinoless double beta decay ββ(0ν) is a test of physics beyond the Standard Model by involving the existence of a massive Majorana neutrino (ν = ν-bar). To try to observe such a process with a sensitivity of 0.1 eV on the neutrino effective mass ( ν >), NEMO collaboration build the NEMO3 detector, able to measure half-lives greater than 10 24 years, corresponding to a few detected events per year. For that, it is necessary to know and master all background sources. This work was first dedicated to the study of external (to the double beta source) background with crossing electrons recorded with NEMO2 prototype detector and then to the simulation of this background in NEMO3 detector. Comparison between NEMO2 data and results of gamma and neutron simulations for different shieldings, with and without neutron source, has allowed to determine background contributions of radon, thoron, 208 Tl contaminations in materials, photon flux produced in laboratory and neutrons. This study, which has required improvements in the MICAP neutron simulation code by developing a photon generator, proved that radiative capture of fast neutrons thermalized in the detector was the source of events in the energy domain of the ββ(0ν) signal. In order to reach the required sensitivity on ν > mass, it has been shown that both a neutron shielding and magnetic field are necessary for NEMO3 detector. (author) [fr

  13. Epithelial NEMO/IKKγ limits fibrosis and promotes regeneration during pancreatitis.

    Science.gov (United States)

    Chan, Lap Kwan; Gerstenlauer, Melanie; Konukiewitz, Björn; Steiger, Katja; Weichert, Wilko; Wirth, Thomas; Maier, Harald Jakob

    2017-11-01

    Inhibitory κB kinase (IKK)/nuclear factor κB (NF-κB) signalling has been implicated in the pathogenesis of pancreatitis, but its precise function has remained controversial. Here, we analyse the contribution of IKK/NF-κB signalling in epithelial cells to the pathogenesis of pancreatitis by targeting the IKK subunit NF-κB essential modulator (NEMO) (IKKγ), which is essential for canonical NF-κB activation. Mice with a targeted deletion of NEMO in the pancreas were subjected to caerulein pancreatitis. Pancreata were examined at several time points and analysed for inflammation, fibrosis, cell death, cell proliferation, as well as cellular differentiation. Human samples were used to corroborate findings established in mice. In acute pancreatitis, NEMO deletion in the pancreatic parenchyma resulted in minor changes during the early phase but led to the persistence of inflammatory and fibrotic foci in the recovery phase. In chronic pancreatitis, NEMO deletion aggravated inflammation and fibrosis, inhibited compensatory acinar cell proliferation, and enhanced acinar atrophy and acinar-ductal metaplasia. Gene expression analysis revealed sustained activation of profibrogenic genes and the CXCL12/CXCR4 axis in the absence of epithelial NEMO. In human chronic pancreatitis samples, the CXCL12/CXCR4 axis was activated as well, with CXCR4 expression correlating with the degree of fibrosis. The aggravating effects of NEMO deletion were attenuated by the administration of the CXCR4 antagonist AMD3100. Our results suggest that NEMO in epithelial cells exerts a protective effect during pancreatitis by limiting inflammation and fibrosis and improving acinar cell regeneration. The CXCL12/CXCR4 axis is an important mediator of that effect and may also be of importance in human chronic pancreatitis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  14. A comparative signaling cost analysis of Macro Mobility scheme in NEMO (MM-NEMO) with mobility management protocol

    Science.gov (United States)

    Islam, Shayla; Abdalla, Aisha H.; Habaebi, Mohamed H.; Latif, Suhaimi A.; Hassan, Wan H.; Hasan, Mohammad K.; Ramli, H. A. M.; Khalifa, Othman O.

    2013-12-01

    NEMO BSP is an upgraded addition to Mobile IPv6 (MIPv6). As MIPv6 and its enhancements (i.e. HMIPv6) possess some limitations like higher handoff latency, packet loss, NEMO BSP also faces all these shortcomings by inheritance. Network Mobility (NEMO) is involved to handle the movement of Mobile Router (MR) and it's Mobile Network Nodes (MNNs) during handoff. Hence it is essential to upgrade the performance of mobility management protocol to obtain continuous session connectivity with lower delay and packet loss in NEMO environment. The completion of handoff process in NEMO BSP usually takes longer period since MR needs to register its single primary care of address (CoA) with home network that may cause performance degradation of the applications running on Mobile Network Nodes. Moreover, when a change in point of attachment of the mobile network is accompanied by a sudden burst of signaling messages, "Signaling Storm" occurs which eventually results in temporary congestion, packet delays or even packet loss. This effect is particularly significant for wireless environment where a wireless link is not as steady as a wired link since bandwidth is relatively limited in wireless link. Hence, providing continuous Internet connection without any interruption through applying multihoming technique and route optimization mechanism in NEMO are becoming the center of attention to the current researchers. In this paper, we propose a handoff cost model to compare the signaling cost of MM-NEMO with NEMO Basic Support Protocol (NEMO BSP) and HMIPv6.The numerical results shows that the signaling cost for the MM-NEMO scheme is about 69.6 % less than the NEMO-BSP and HMIPv6.

  15. A comparative signaling cost analysis of Macro Mobility scheme in NEMO (MM-NEMO) with mobility management protocol

    International Nuclear Information System (INIS)

    Islam, Shayla; Abdalla, Aisha H; Habaebi, Mohamed H; Latif, Suhaimi A; Hassan, Wan H; Hasan, Mohammad K; Ramli, H A M; Khalifa, Othman O

    2013-01-01

    NEMO BSP is an upgraded addition to Mobile IPv6 (MIPv6). As MIPv6 and its enhancements (i.e. HMIPv6) possess some limitations like higher handoff latency, packet loss, NEMO BSP also faces all these shortcomings by inheritance. Network Mobility (NEMO) is involved to handle the movement of Mobile Router (MR) and it's Mobile Network Nodes (MNNs) during handoff. Hence it is essential to upgrade the performance of mobility management protocol to obtain continuous session connectivity with lower delay and packet loss in NEMO environment. The completion of handoff process in NEMO BSP usually takes longer period since MR needs to register its single primary care of address (CoA) with home network that may cause performance degradation of the applications running on Mobile Network Nodes. Moreover, when a change in point of attachment of the mobile network is accompanied by a sudden burst of signaling messages, ''Signaling Storm'' occurs which eventually results in temporary congestion, packet delays or even packet loss. This effect is particularly significant for wireless environment where a wireless link is not as steady as a wired link since bandwidth is relatively limited in wireless link. Hence, providing continuous Internet connection without any interruption through applying multihoming technique and route optimization mechanism in NEMO are becoming the center of attention to the current researchers. In this paper, we propose a handoff cost model to compare the signaling cost of MM-NEMO with NEMO Basic Support Protocol (NEMO BSP) and HMIPv6.The numerical results shows that the signaling cost for the MM-NEMO scheme is about 69.6 % less than the NEMO-BSP and HMIPv6

  16. Nor-ursodeoxycholic acid reverses hepatocyte-specific nemo-dependent steatohepatitis.

    Science.gov (United States)

    Beraza, Naiara; Ofner-Ziegenfuss, Lisa; Ehedego, Haksier; Boekschoten, Mark; Bischoff, Stephan C; Mueller, Michael; Trauner, Michael; Trautwein, Christian

    2011-03-01

    Hepatocyte-specific NEMO/NF-κB deleted mice (NEMO(Δhepa)) develop spontaneous non-alcoholic steatohepatitis (NASH). Free fatty acids and bile acids promote DR5 expression. TRAIL/NK cell-mediated activation of TRAIL-R2/DR5 plays an important role during acute injury in NEMO(Δhepa) mice. To inhibit the progression of NASH in the absence of hepatocyte-NEMO/NF-kB signaling. NEMOf/f and NEMO(Δhepa) mice were fed with a low-fat diet, and with two anticholestatic diets; UDCA and NorUDCA. The impact of these treatments on the progression of NASH was evaluated. We show that high expression of DR5 in livers from NEMO(Δhepa) mice is accompanied by an abundant presence of bile acids (BAs), misregulation of BA transporters and significant alteration of lipid metabolism-related genes. Additionally, mice lacking NEMO in hepatocytes spontaneously showed ductular response at young age. Unexpectedly, feeding of NEMO(Δhepa) mice with low-fat diet failed to improve chronic liver injury. Conversely, anti-cholestatic treatment with nor-ursodeoxycholic acid (NorUDCA), but not with ursodeoxycholic acid (UDCA), led to a significant attenuation of liver damage in NEMO(Δhepa) mice. The strong therapeutic effect of NorUDCA relied on a significant downregulation of LXR-dependent lipogenesis and the normalisation of BA metabolism through mechanisms involving cross-talk between Cyp7a1 and SHP. This was associated with the significant improvement of liver histology, NEMO(Δhepa)/NorUDCA-treated mice showed lower apoptosis and reduced CyclinD1 expression, indicating attenuation of the compensatory proliferative response to hepatocellular damage. Finally, fibrosis and ductular reaction markers were significantly reduced in NorUDCA-treated NEMO(Δhepa) mice. Overall, our work demonstrates the contribution of bile acids metabolism to the progression of NASH in the absence of hepatocyte-NF-kB through mechanisms involving DR5-apoptosis, inflammation and fibrosis. Our work suggests a potential

  17. Double hit of NEMO gene in preeclampsia.

    Directory of Open Access Journals (Sweden)

    Agata Sakowicz

    Full Text Available The precise etiology of preeclampsia is unknown. Family studies indicate that both genetic and environmental factors influence its development. One of these factors is NFkB, whose activation depends on NEMO (NFkB essential modulator. This is the first study to investigate the association between the existence of single nucleotide variant of the NEMO gene and the appearance of preeclampsia. A total of 151 women (72 preeclamptic women and 79 controls and their children were examined. Sanger sequencing was performed to identify variants in the NEMO gene in the preeclamptic mothers. The maternal identified variants were then sought in the studied groups of children, and in the maternal and child controls, using RFLP-PCR. Real-time RT-PCR was performed to assess NEMO gene expression in maternal blood, umbilical cord blood and placentas. The sequencing process indicated the existence of two different variants in the 3'UTR region of the NEMO gene of preeclamptic women (IKBKG:c.*368C>A and IKBKG:c.*402C>T. The simultaneous occurrence of the TT genotype in the mother and the TT genotype in the daughter or a T allele in the son increased the risk of preeclampsia development 2.59 fold. Additionally, we found that the configuration of maternal/fetal genotypes (maternal TT/ daughter TT or maternal TT/son T of IKBKG:c.*402C/T variant is associated with the level of NEMO gene expression. Our results showed that, the simultaneous occurrence of the maternal TT genotype (IKBKG:c.*402C>T variants and TT genotype in the daughter or T allele in the son correlates with the level of NEMO gene expression and increases the risk of preeclampsia development. Our observations may offer a new insight into the genetic etiology and pathogenesis of preeclampsia.

  18. Expanding the substantial interactome of NEMO using protein microarrays.

    LENUS (Irish Health Repository)

    Fenner, Beau J

    2010-01-01

    Signal transduction by the NF-kappaB pathway is a key regulator of a host of cellular responses to extracellular and intracellular messages. The NEMO adaptor protein lies at the top of this pathway and serves as a molecular conduit, connecting signals transmitted from upstream sensors to the downstream NF-kappaB transcription factor and subsequent gene activation. The position of NEMO within this pathway makes it an attractive target from which to search for new proteins that link NF-kappaB signaling to additional pathways and upstream effectors. In this work, we have used protein microarrays to identify novel NEMO interactors. A total of 112 protein interactors were identified, with the most statistically significant hit being the canonical NEMO interactor IKKbeta, with IKKalpha also being identified. Of the novel interactors, more than 30% were kinases, while at least 25% were involved in signal transduction. Binding of NEMO to several interactors, including CALB1, CDK2, SAG, SENP2 and SYT1, was confirmed using GST pulldown assays and coimmunoprecipitation, validating the initial screening approach. Overexpression of CALB1, CDK2 and SAG was found to stimulate transcriptional activation by NF-kappaB, while SYT1 overexpression repressed TNFalpha-dependent NF-kappaB transcriptional activation in human embryonic kidney cells. Corresponding with this finding, RNA silencing of CDK2, SAG and SENP2 reduced NF-kappaB transcriptional activation, supporting a positive role for these proteins in the NF-kappaB pathway. The identification of a host of new NEMO interactors opens up new research opportunities to improve understanding of this essential cell signaling pathway.

  19. Advanced energy systems and technologies research in Finland. NEMO 2 annual report 1994-1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    Advanced energy technologies were linked to the national energy research in beginning of 1988 when energy research was reorganised in Finland. The Ministry of Trade and Industry set up many energy research programmes and NEMO was one of them. Major objectives of the programme were to assess the potential of new energy systems for the national energy supply system and to promote industrial activities. Within the NEMO 2 programme for the years 1993-1998, research was focused on technological solutions. In the beginning of the 1995, the national energy research activities were passed on to the Technology Development Centre TEKES. The NEMO 2 programme is directed towards those areas that have particular potential for commercial exploitation or development. Emphasis is placed particularly on solar and wind energy, as well as supporting technologies such as energy storage and hydrogen technology. Resources has been focused on three specific areas: Arctic wind technology, wind turbine components, and the integration of solar energy into applications (including thin film solar cells). It seems that in Finland the growth of the new energy technology industry is focused on these areas. The sales of the industry have been growing considerable due to the national research activities and support of technology development. The sales have increased 6 - 7 times compared to the year 1987 and is now over 200 million FIM. The support to industries and their involvement in the program has grown more than 15 times compared to 1988. The total funding of the NEMO 2 program me was 30 million FIM in 1994 and 21 million FIM in 1995. The programme consists of 20 research projects, 15 joint development projects, and 5 EU projects. In this report, the essential research projects of the programme in 1994-1995 are described. The total funding for these projects was about 25 million FIM, of which the TEKES`s share was about half. When the research projects and joint development projects are

  20. Quantification of cellular NEMO content and its impact on NF-κB activation by genotoxic stress.

    Directory of Open Access Journals (Sweden)

    Byounghoon Hwang

    Full Text Available NF-κB essential modulator, NEMO, plays a key role in canonical NF-κB signaling induced by a variety of stimuli, including cytokines and genotoxic agents. To dissect the different biochemical and functional roles of NEMO in NF-κB signaling, various mutant forms of NEMO have been previously analyzed. However, transient or stable overexpression of wild-type NEMO can significantly inhibit NF-κB activation, thereby confounding the analysis of NEMO mutant phenotypes. What levels of NEMO overexpression lead to such an artifact and what levels are tolerated with no significant impact on NEMO function in NF-κB activation are currently unknown. Here we purified full-length recombinant human NEMO protein and used it as a standard to quantify the average number of NEMO molecules per cell in a 1.3E2 NEMO-deficient murine pre-B cell clone stably reconstituted with full-length human NEMO (C5. We determined that the C5 cell clone has an average of 4 x 10(5 molecules of NEMO per cell. Stable reconstitution of 1.3E2 cells with different numbers of NEMO molecules per cell has demonstrated that a 10-fold range of NEMO expression (0.6-6x10(5 molecules per cell yields statistically equivalent NF-κB activation in response to the DNA damaging agent etoposide. Using the C5 cell line, we also quantified the number of NEMO molecules per cell in several commonly employed human cell lines. These results establish baseline numbers of endogenous NEMO per cell and highlight surprisingly normal functionality of NEMO in the DNA damage pathway over a wide range of expression levels that can provide a guideline for future NEMO reconstitution studies.

  1. Spectral modeling of scintillator for the NEMO-3 and SuperNEMO detectors

    Energy Technology Data Exchange (ETDEWEB)

    Argyriades, J. [LAL, Universite Paris-Sud, CNRS/IN2P3, F-91405 Orsay (France); Arnold, R. [IPHC, Universite de Strasbourg, CNRS/IN2P3, F-67037 Strasbourg (France); Augier, C. [LAL, Universite Paris-Sud, CNRS/IN2P3, F-91405 Orsay (France); Baker, J. [INL, Idaho Falls, 83415 (United States); Barabash, A.S. [Institute of Theoretical and Experimental Physics, 117259 Moscow (Russian Federation); Bongrand, M.; Broudin-Bay, G. [LAL, Universite Paris-Sud, CNRS/IN2P3, F-91405 Orsay (France); Brudanin, V.B. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Caffrey, A.J. [INL, Idaho Falls, 83415 (United States); Cebrian, S. [University of Zaragoza, C/ Pedro Cerbuna 12, 50009 Zaragoza (Spain); Chapon, A. [LPC Caen, ENSICAEN, Universite de Caen, CNRS/IN2P3, F-14032 Caen (France); Chauveau, E. [CNRS/IN2P3, Centre d' Etudes Nucleaires de Bordeaux Gradignan, UMR 5797, F-33175 Gradignan (France); Universite de Bordeaux, Centre d' Etudes Nucleaires de Bordeaux Gradignan, UMR 5797, F-33175 Gradignan (France); Dafni, Th. [University of Zaragoza, C/ Pedro Cerbuna 12, 50009 Zaragoza (Spain); Daraktchieva, Z. [University College London, WC1E 6BT London (United Kingdom); Diaz, J. [IFIC, CSIC - Universidad de Valencia, Valencia (Spain); Durand, D. [LPC Caen, ENSICAEN, Universite de Caen, CNRS/IN2P3, F-14032 Caen (France); Egorov, V.G. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Evans, J.J. [University College London, WC1E 6BT London (United Kingdom); Fatemi-Ghomi, N. [University of Manchester, M13 9PL Manchester (United Kingdom); Flack, R. [University College London, WC1E 6BT London (United Kingdom)

    2011-01-01

    We have constructed a GEANT4-based detailed software model of photon transport in plastic scintillator blocks and have used it to study the NEMO-3 and SuperNEMO calorimeters employed in experiments designed to search for neutrinoless double beta decay. We compare our simulations to measurements using conversion electrons from a calibration source of {sup 207}Bi and show that the agreement is improved if wavelength-dependent properties of the calorimeter are taken into account. In this article, we briefly describe our modeling approach and results of our studies.

  2. Advanced energy systems and technologies research in Finland. NEMO-2 Programme Annual Report 1996-1997

    International Nuclear Information System (INIS)

    1998-01-01

    Advanced energy technologies were linked to the national energy research in the beginning of 1988 when energy research was reorganised in Finland. The Ministry of Trade and Industry established several energy research programmes and NEMO was one of them. Major objectives of the programme were to assess the potential of new energy systems for the national energy supply system and to promote industrial activities. Within the NEMO 2 programme for the years 1993-1998, research was focused on a few promising technological solutions. In the beginning of 1995, the national energy research activities were passed on to the Technology Development Centre TEKES. The NEMO 2 programme is directed towards those areas that have particular potential for commercial exploitation or development. Emphasis is placed particularly on solar and wind energy, as well as supporting technologies, such as energy storage and hydrogen technology. Resources have been focused on three specific areas: arctic wind technology, wind turbine components, and the integration of solar energy into applications (including thin film solar cells). In Finland, the growth of the new energy technology industry is concentrated on these areas. The turnover of the Finnish industry has been growing considerably due to the national research activities and support of technology development. The sales have increased more than 10 times compared with the year 1987 and is now over 300 million FIM. The support to industries and their involvement in the program has grown considerably. In this report, the essential research projects of the programme during 1996-1997 are described. The total funding for these projects was about 30 million FIM per year, of which the TEKES's share was about 40 per cent. The programme consists of 10 research projects, some 15 joint development projects, and 9 EU projects. In case the research projects and joint development projects are acting very closely, the description of the project is

  3. Advanced energy systems and technologies research in Finland. NEMO-2 Programme Annual Report 1996-1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-10-01

    Advanced energy technologies were linked to the national energy research in the beginning of 1988 when energy research was reorganised in Finland. The Ministry of Trade and Industry established several energy research programmes and NEMO was one of them. Major objectives of the programme were to assess the potential of new energy systems for the national energy supply system and to promote industrial activities. Within the NEMO 2 programme for the years 1993-1998, research was focused on a few promising technological solutions. In the beginning of 1995, the national energy research activities were passed on to the Technology Development Centre TEKES. The NEMO 2 programme is directed towards those areas that have particular potential for commercial exploitation or development. Emphasis is placed particularly on solar and wind energy, as well as supporting technologies, such as energy storage and hydrogen technology. Resources have been focused on three specific areas: arctic wind technology, wind turbine components, and the integration of solar energy into applications (including thin film solar cells). In Finland, the growth of the new energy technology industry is concentrated on these areas. The turnover of the Finnish industry has been growing considerably due to the national research activities and support of technology development. The sales have increased more than 10 times compared with the year 1987 and is now over 300 million FIM. The support to industries and their involvement in the program has grown considerably. In this report, the essential research projects of the programme during 1996-1997 are described. The total funding for these projects was about 30 million FIM per year, of which the TEKES`s share was about 40 per cent. The programme consists of 10 research projects, some 15 joint development projects, and 9 EU projects. In case the research projects and joint development projects are acting very closely, the description of the project is

  4. NEMO: A Stellar Dynamics Toolbox

    Science.gov (United States)

    Barnes, Joshua; Hut, Piet; Teuben, Peter

    2010-10-01

    NEMO is an extendible Stellar Dynamics Toolbox, following an Open-Source Software model. It has various programs to create, integrate, analyze and visualize N-body and SPH like systems, following the pipe and filter architecture. In addition there are various tools to operate on images, tables and orbits, including FITS files to export/import to/from other astronomical data reduction packages. A large growing fraction of NEMO has been contributed by a growing list of authors. The source code consist of a little over 4000 files and a little under 1,000,000 lines of code and documentation, mostly C, and some C++ and Fortran. NEMO development started in 1986 in Princeton (USA) by Barnes, Hut and Teuben. See also ZENO (ascl:1102.027) for the version that Barnes maintains.

  5. Neutrino Physics without Neutrinos: Recent results from the NEMO-3 experiment and plans for SuperNEMO

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    The observation of neutrino oscillations has proved that neutrinos have mass. This discovery has renewed and strengthened the interest in neutrinoless double beta decay experiments which provide the only practical way to determine whether neutrinos are Majorana or Dirac particles. The recently completed NEMO-3 experiment, located in the Laboratoire Souterrain de Modane in the Frejus Tunnel, was an experiment searching for neutrinoless double beta decays using a powerful technique for detecting a two-electron final state by employing an apparatus combining tracking, calorimetry, and the time-of-flight measurements. We will present latest results from NEMO-3 and will discuss the status of SuperNEMO, the next generation experiment that will exploit the same experimental technique to extend the sensitivity of the current search.

  6. BAHAN AJAR MENULIS CERITA FABEL DENGAN STIMULUS FILM FINDING NEMO

    Directory of Open Access Journals (Sweden)

    Lia Noviana Qostantia

    2017-03-01

    Full Text Available This research objectives were (1 describing instructional material of writing fable story using stimulus of finding nemo movie and (2 describing instructional material feasibility of writing fable story using stimulus of Finding Nemo movie that obtained from expert test and practitioner (teacher and student test. The developed instructional material was complementary book of writing fable story for students with material, language, and book display that adjusted with student’s needs. Those objectives could be made as guidance in developing the instructional material which including material content feasibility, language, and complementary book display aspect. Tujuan penelitian ini adalah (1 mengembangkan bahan ajar menulis cerita fabel dengan stimulus film finding nemo, (2 mendeskripsikan kelayakan bahan ajar menulis cerita fabel dengan stimulus film Finding Nemo yang diperoleh dari uji ahli, uji praktisi guru, dan siswa. Bahan ajar yang dikembangkan berupa buku pelengkap menulis cerita fabel untuk siswa dengan materi, bahasa, dan penyajian buku yang disesuaikan dengan kebutuhan siswa. Tujuan tersebut dapat dijadikan panduan dalam mengembangkan bahan ajar yang mencakup aspek kelayakan isi materi, bahasa, dan penyajian buku pelengkap.

  7. Background constrains of the SuperNEMO experiment for neutrinoless double beta-decay searches

    Energy Technology Data Exchange (ETDEWEB)

    Povinec, Pavel P.

    2017-02-11

    The SuperNEMO experiment is a new generation of experiments dedicated to the search for neutrinoless double beta-decay, which if observed, would confirm the existence of physics beyond the Standard Model. It is based on the tracking and calorimetry techniques, which allow the reconstruction of the final state topology, including timing and kinematics of the double beta-decay transition events, offering a powerful tool for background rejection. While the basic detection strategy of the SuperNEMO detector remains the same as of the NEMO-3 detector, a number of improvements were accomplished for each of detector main components. Upgrades of the detector technologies and development of low-level counting techniques ensure radiopurity control of construction parts of the SuperNEMO detector. A reference material made of glass pellets has been developed to assure quality management and quality control of radiopurity measurements. The first module of the SuperNEMO detector (Demonstrator) is currently under construction in the Modane underground laboratory. No background event is expected in the neutrinoless double beta-decay region in 2.5 years of its operation using 7 kg of {sup 82}Se. The half-life sensitivity of the Demonstrator is expected to be >6.5·10{sup 24} y, corresponding to an effective Majorana neutrino mass sensitivity of |0.2−0.4| eV (90% C.L.). The full SuperNEMO experiment comprising of 20 modules with 100 kg of {sup 82}Se source should reach an effective Majorana neutrino mass sensitivity of |0.04−0.1| eV, and a half-life limit 1·10{sup 26} y. - Highlights: • SuperNEMO detector for 2β0ν-decay of {sup 82}Se should reach half-life limit of 10{sup 26} y. • Radiopurity of the SuperNEMO internal detector parts was checked down to 0.1 mBq/kg. • Reference material of glass pellets was developed for underground γ-spectrometry.

  8. Nemo-3 experiment assets and limitations. Perspective for the double β physics

    International Nuclear Information System (INIS)

    Augier, C.

    2005-06-01

    After an introduction to this report in Chapter 1, I present a status of our knowledge in neutrino physics in Chapter 2. Then, I detail in Chapter 3 all the choices made for the design and realisation of the NEMO 3 detector for the research of double beta decay process. Performance of the detector is presented, concerning both the capacity of the detector to identify the backgrounds and the ability to study all the ββ process. I also explain the methods chosen by the NEMO collaboration to reduce the radon activity inside the detector and to make this background negligible today. This chapter, which is written in English, is the 'Technical report of the NEMO 3 detector' and forms an independent report for the NEMO collaborators. I finish this report in Chapter 4 with a ten years prospect for experimental projects in physics, with both the SuperNEMO project and its experiment program, and also by comparing the most interesting experiments, CUORE and GERDA, showing as an example the effect of nuclear matrix elements on the neutrino effective mass measurement. (author)

  9. Disulfide-mediated stabilization of the IκB kinase binding domain of NF-κB essential modulator (NEMO).

    Science.gov (United States)

    Zhou, Li; Yeo, Alan T; Ballarano, Carmine; Weber, Urs; Allen, Karen N; Gilmore, Thomas D; Whitty, Adrian

    2014-12-23

    Human NEMO (NF-κB essential modulator) is a 419 residue scaffolding protein that, together with catalytic subunits IKKα and IKKβ, forms the IκB kinase (IKK) complex, a key regulator of NF-κB pathway signaling. NEMO is an elongated homodimer comprising mostly α-helix. It has been shown that a NEMO fragment spanning residues 44-111, which contains the IKKα/β binding site, is structurally disordered in the absence of bound IKKβ. Herein we show that enforcing dimerization of NEMO1-120 or NEMO44-111 constructs through introduction of one or two interchain disulfide bonds, through oxidation of the native Cys54 residue and/or at position 107 through a Leu107Cys mutation, induces a stable α-helical coiled-coil structure that is preorganized to bind IKKβ with high affinity. Chemical and thermal denaturation studies showed that, in the context of a covalent dimer, the ordered structure was stabilized relative to the denatured state by up to 3 kcal/mol. A full-length NEMO-L107C protein formed covalent dimers upon treatment of mammalian cells with H2O2. Furthermore, NEMO-L107C bound endogenous IKKβ in A293T cells, reconstituted TNF-induced NF-κB signaling in NEMO-deficient cells, and interacted with TRAF6. Our results indicate that the IKKβ binding domain of NEMO possesses an ordered structure in the unbound state, provided that it is constrained within a dimer as is the case in the constitutively dimeric full-length NEMO protein. The stability of the NEMO coiled coil is maintained by strong interhelix interactions in the region centered on residue 54. The disulfide-linked constructs we describe herein may be useful for crystallization of NEMO's IKKβ binding domain in the absence of bound IKKβ, thereby facilitating the structural characterization of small-molecule inhibitors.

  10. PORFIDO: Oceanographic data for neutrino telescopes

    International Nuclear Information System (INIS)

    Cordelli, Marco; Martini, Agnese; Habel, Roberto; Trasatti, Luciano

    2011-01-01

    PORFIDO (Physical Oceanography by RFID Outreach) is a system designed to be installed in the optical modules of the NEMO experiment and possibly, in future underwater neutrino telescopes to gather oceanographic data with a minimum of disturbance to the main project and a very limited budget. The system gathers oceanographic data (temperature, etc.) from passive RFID tags (WISPs) attached to the outside of the NEMO optical modules with an RF reader situated inside the glass sphere, without the need of connectors or penetrators, which are very expensive and offer low reliability. Ten PORFIDOs will be deployed with the NEMO Phase 2 tower in 2011.

  11. PORFIDO: Oceanographic data for neutrino telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Cordelli, Marco; Martini, Agnese; Habel, Roberto [INFN-Laboratori Nazionali di Frascati, Via E. Fermi 40, I-00044 Frascati (Italy); Trasatti, Luciano, E-mail: luciano.trasatti@gmail.co [INFN-Laboratori Nazionali di Frascati, Via E. Fermi 40, I-00044 Frascati (Italy)

    2011-01-21

    PORFIDO (Physical Oceanography by RFID Outreach) is a system designed to be installed in the optical modules of the NEMO experiment and possibly, in future underwater neutrino telescopes to gather oceanographic data with a minimum of disturbance to the main project and a very limited budget. The system gathers oceanographic data (temperature, etc.) from passive RFID tags (WISPs) attached to the outside of the NEMO optical modules with an RF reader situated inside the glass sphere, without the need of connectors or penetrators, which are very expensive and offer low reliability. Ten PORFIDOs will be deployed with the NEMO Phase 2 tower in 2011.

  12. Strategy of HPGe screening measurements in the SuperNEMO experiment

    Energy Technology Data Exchange (ETDEWEB)

    Perrot, Frédéric [Université de Bordeaux, Centre d' Etudes Nucléaires de Bordeaux Gradignan, UMR 5797, Chemin du Solarium, Le Haut-Vigneau, BP120, F-33175 Gradignan, France and CNRS/IN2P3, Centre d' Etudes Nucléaires de Bordeaux Gradignan, UMR 5797 (France); Collaboration: SuperNEMO Collaboration

    2013-08-08

    SuperNEMO is a double beta decay experiment that will use a tracko-calorimeter technique. The goal is to reach a sensitivity of T{sub 1/2}(0ν)>10{sup 26} y corresponding to an effective Majorana neutrino mass of 0.04-0.11 eV with 100 kg of {sup 82}Se. The general strategy of the HPGe screening measurements is described for the materials of the SuperNEMO demonstrator, regarding their radiopurity and their location. The two platforms, PRISNA and LSM, used for this screening are also briefly described.

  13. NEMO-SN1 observatory developments in view of the European Research Infrastructures EMSO and KM3NET

    Energy Technology Data Exchange (ETDEWEB)

    Favali, Paolo, E-mail: emsopp@ingv.i [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sect. Roma 2, Via di Vigna Murata 605, 00143 Roma (Italy); Beranzoli, Laura [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sect. Roma 2, Via di Vigna Murata 605, 00143 Roma (Italy); Italiano, Francesco [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sect. Palermo, Via Ugo La Malfa 153, 90146 Palermo (Italy); Migneco, Emilio; Musumeci, Mario; Papaleo, Riccardo [Istituto Nazionale di Fisica Nucleare (INFN), Laboratori Nazionali del Sud, Via di S. Sofia 62, 95125 Catania (Italy)

    2011-01-21

    NEMO-SN1 (Western Ionian Sea off Eastern Sicily), the first real-time multiparameter observatory operating in Europe since 2005, is one of the nodes of the upcoming European ESFRI large-scale research infrastructure EMSO (European Multidisciplinary Seafloor Observatory), a network of seafloor observatories placed at marine sites on the European Continental Margin. NEMO-SN1 constitutes also an important test-site for the study of prototypes of Kilometre Cube Neutrino Telescope (KM3NeT), another European ESFRI large-scale research infrastructure. Italian resources have been devoted to the development of NEMO-SN1 facilities and logistics, as with the PEGASO project, while the EC project ESONET-NoE is funding a demonstration mission and a technological test. EMSO and KM3NeT are presently in the Preparatory Phase as projects funded under the EC-FP7.

  14. Cellular automaton and elastic net for event reconstruction in the NEMO-2 experiment

    International Nuclear Information System (INIS)

    Kisel, I.; Kovalenko, V.; Laplanche, F.

    1997-01-01

    A cellular automaton for track searching combined with an elastic net for charged particle trajectory fitting is presented. The advantages of the methods are: the simplicity of the algorithms, the fast and stable convergency to real tracks, and a good reconstruction efficiency. The combination of techniques have been used with success for event reconstruction on the data of the NEMO-2 double-beta (ββ) decay experiments. (orig.)

  15. RedNemo

    DEFF Research Database (Denmark)

    Alkan, Ferhat; Erten, Cesim

    2017-01-01

    is their erroneous nature; they contain false-positive interactions and usually many more false-negatives. Recently, several computational methods have been proposed for network reconstruction based on topology, where given an input PPI network the goal is to reconstruct the network by identifying false...... material including source code, useful scripts, experimental data and the results are available at http://webprs.khas.edu.tr/∼cesim/Red Nemo. tar.gz CONTACT: cesim@khas.edu.tr Supplementary information: Supplementary data are available at Bioinformatics online....

  16. Modelling turbulent vertical mixing sensitivity using a 1-D version of NEMO

    Science.gov (United States)

    Reffray, G.; Bourdalle-Badie, R.; Calone, C.

    2015-01-01

    Through two numerical experiments, a 1-D vertical model called NEMO1D was used to investigate physical and numerical turbulent-mixing behaviour. The results show that all the turbulent closures tested (k+l from Blanke and Delecluse, 1993, and two equation models: generic length scale closures from Umlauf and Burchard, 2003) are able to correctly reproduce the classical test of Kato and Phillips (1969) under favourable numerical conditions while some solutions may diverge depending on the degradation of the spatial and time discretization. The performances of turbulence models were then compared with data measured over a 1-year period (mid-2010 to mid-2011) at the PAPA station, located in the North Pacific Ocean. The modelled temperature and salinity were in good agreement with the observations, with a maximum temperature error between -2 and 2 °C during the stratified period (June to October). However, the results also depend on the numerical conditions. The vertical RMSE varied, for different turbulent closures, from 0.1 to 0.3 °C during the stratified period and from 0.03 to 0.15 °C during the homogeneous period. This 1-D configuration at the PAPA station (called PAPA1D) is now available in NEMO as a reference configuration including the input files and atmospheric forcing set described in this paper. Thus, all the results described can be recovered by downloading and launching PAPA1D. The configuration is described on the NEMO site (PAPA">http://www.nemo-ocean.eu/Using-NEMO/Configurations/C1D_PAPA). This package is a good starting point for further investigation of vertical processes.

  17. GeNemo: a search engine for web-based functional genomic data.

    Science.gov (United States)

    Zhang, Yongqing; Cao, Xiaoyi; Zhong, Sheng

    2016-07-08

    A set of new data types emerged from functional genomic assays, including ChIP-seq, DNase-seq, FAIRE-seq and others. The results are typically stored as genome-wide intensities (WIG/bigWig files) or functional genomic regions (peak/BED files). These data types present new challenges to big data science. Here, we present GeNemo, a web-based search engine for functional genomic data. GeNemo searches user-input data against online functional genomic datasets, including the entire collection of ENCODE and mouse ENCODE datasets. Unlike text-based search engines, GeNemo's searches are based on pattern matching of functional genomic regions. This distinguishes GeNemo from text or DNA sequence searches. The user can input any complete or partial functional genomic dataset, for example, a binding intensity file (bigWig) or a peak file. GeNemo reports any genomic regions, ranging from hundred bases to hundred thousand bases, from any of the online ENCODE datasets that share similar functional (binding, modification, accessibility) patterns. This is enabled by a Markov Chain Monte Carlo-based maximization process, executed on up to 24 parallel computing threads. By clicking on a search result, the user can visually compare her/his data with the found datasets and navigate the identified genomic regions. GeNemo is available at www.genemo.org. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  18. Development of quantum device simulator NEMO-VN1

    Science.gov (United States)

    Hien, Dinh Sy; Thi Luong, Nguyen; Hoang Minh, Le; Tien Phuc, Tran; Thanh Trung, Pham; Dong, Bui An; Thu Thao, Huynh Lam; Van Le Thanh, Nguyen; Tuan, Thi Tran Anh; Hoang Trung, Huynh; Thi Thanh Nhan, Nguyen; Viet Nga, Dinh

    2009-09-01

    We have developed NEMO-VN1 (NanoElectronic MOdelling), a new modelling tool that simulates a wide variety of quantum devices including Quantum Dot (QD), Resonant Tunneling Diode (RTD), Resonant Tunneling Transistor (RTT), Single Electron Transistor (SET), Molecular FET (MFET), Carbon Nanotube FET (CNTFET), Spin FET (SPINFET). It has a collection of models that allow user to trade off between calculation speed and accuracy. NEMO-VN1 also includes a graphic user interface of Matlab that enables parameter entry, calculation control, intuitive display of calculation results, and in-situ data analysis methods.

  19. Development of quantum device simulator NEMO-VN1

    International Nuclear Information System (INIS)

    Dinh Sy Hien; Nguyen Thi Luong; Le Hoang Minh; Tran Tien Phuc; Pham Thanh Trung; Bui An Dong; Huynh Lam Thu Thao; Nguyen Van Le Thanh; Thi Tran Anh Tuan; Huynh Hoang Trung; Nguyen Thi Thanh Nhan; Dinh Viet Nga

    2009-01-01

    We have developed NEMO-VN1 (NanoElectronic MOdelling), a new modelling tool that simulates a wide variety of quantum devices including Quantum Dot (QD), Resonant Tunneling Diode (RTD), Resonant Tunneling Transistor (RTT), Single Electron Transistor (SET), Molecular FET (MFET), Carbon Nanotube FET (CNTFET), Spin FET (SPINFET). It has a collection of models that allow user to trade off between calculation speed and accuracy. NEMO-VN1 also includes a graphic user interface of Matlab that enables parameter entry, calculation control, intuitive display of calculation results, and in-situ data analysis methods.

  20. Low background techniques for SuperNEMO

    International Nuclear Information System (INIS)

    Liu, Xin Ran; Mott, James

    2015-01-01

    The UK contribution to achieving the ultra-low background conditions required inside the detectors of the SuperNEMO experiment are described. A dedicated facility has been established for the screening and selection of materials through gamma ray spectroscopy using germanium detectors. Initial results from two detectors are shown. The radon level inside the SuperNEMO detector must be less than 150 μBq/m 3 in order to achieve the target sensitivity. A Radon Concentration Line (RnCL) has been developed capable of measuring radon levels in large gas volumes down to 5 μBq/m 3 , improving on standard state-of-the-art radon detectors by 3 orders of magnitude. The development, commissioning and first measurements of radon content using the RnCL are also presented. (paper)

  1. Porcine deltacoronavirus nsp5 inhibits interferon-β production through the cleavage of NEMO.

    Science.gov (United States)

    Zhu, Xinyu; Fang, Liurong; Wang, Dang; Yang, Yuting; Chen, Jiyao; Ye, Xu; Foda, Mohamed Frahat; Xiao, Shaobo

    2017-02-01

    Porcine deltacoronavirus (PDCoV) causes acute enteric disease and mortality in seronegative neonatal piglets. Previously we have demonstrated that PDCoV infection suppresses the production of interferon-beta (IFN-β), while the detailed mechanisms are poorly understood. Here, we demonstrate that nonstructural protein 5 (nsp5) of PDCoV, the 3C-like protease, significantly inhibits Sendai virus (SEV)-induced IFN-β production by targeting the NF-κB essential modulator (NEMO), confirmed by the diminished function of NEMO cleaved by PDCoV. The PDCoV nsp5 cleavage site in the NEMO protein was identified as glutamine 231, and was identical to the porcine epidemic diarrhea virus nsp5 cleavage site, revealing the likelihood of a common target in NEMO for coronaviruses. Furthermore, this cleavage impaired the ability of NEMO to activate the IFN response and downstream signaling. Taken together, our findings reveal PDCoV nsp5 to be a newly identified IFN antagonist and enhance the understanding of immune evasion by deltacoronaviruses. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Cellular automaton and elastic net for event reconstruction in the NEMO-2 experiment

    International Nuclear Information System (INIS)

    Kovalenko, V.

    1997-01-01

    A cellular automaton for track searching and an elastic net for charged particle trajectory fitting are presented. The advantages of the methods are: simplicity of the algorithms, fast and stable convergence to real tracks, and a reconstruction efficiency close to 100%. Demonstration programs are available at http://nuweb.jinr.dubna.su/LNP/NEMO using a Java enabled browser. (orig.)

  3. Development of an optical simulation for the SuperNEMO calorimeter

    Science.gov (United States)

    Huber, Arnaud; SuperNEMO Collaboration

    2017-09-01

    The SuperNEMO double beta decay project is a modular tracker-calorimeter based experiment. The aim of this project is to reach a sensitivity of the order of 1026 years concerning the neutrinoless double beta decay half-life, corresponding to a Majorana neutrino mass of 50-100 meV. The main calorimeter of the SuperNEMO demonstrator is based on 520 Optical Modules made of large volume plastic scintillators (10L) coupled with large area photomultipliers (Hamamatsu R5912-MOD and R6594). The design of the calorimeter is optimized for the double beta decay detection and allows gamma tagging for background rejection. In large volumes of scintillators, a similar deposited energy by electrons or photons will give different visible energy and signal shapes due to different interactions inside the scintillator. The aim of the optical simulation, developed for SuperNEMO, is to model the Optical Module response on the energy and time performances, regarding the particle type.

  4. Results of the BiPo-1 prototype for radiopurity measurements for the SuperNEMO double beta decay source foils

    Energy Technology Data Exchange (ETDEWEB)

    Argyriades, J. [LAL, Universite Paris-Sud, CNRS/IN2P3, F-91405 Orsay (France); Arnold, R. [IPHC, Universite de Strasbourg, CNRS/IN2P3, F-67037 Strasbourg (France); Augier, C. [LAL, Universite Paris-Sud, CNRS/IN2P3, F-91405 Orsay (France); Baker, J. [INL, Idaho Falls, ID 83415 (United States); Barabash, A.S. [Institute of Theoretical and Experimental Physics, 117259 Moscow (Russian Federation); Basharina-Freshville, A. [University College London, WC1E 6BT London (United Kingdom); Bongrand, M.; Bourgeois, C.; Breton, D.; Briere, M.; Broudin-Bay, G. [LAL, Universite Paris-Sud, CNRS/IN2P3, F-91405 Orsay (France); Brudanin, V.B. [Joint Institute for Neear Research, 141980 Dubna (Russian Federation); Caffrey, A.J. [INL, Idaho Falls, ID 83415 (United States); Carcel, S. [Instituto de Fisica Corpuscular, CSIC, Universidad de Valencia, Valencia (Spain); Cebrian, S. [Instituto de Fisica Nuclear y Altas Energias, Universidad de Zaragoza, Zaragoza (Spain); Chapon, A. [LPC Caen, ENSICAEN, Universite de Caen, CNRS/IN2P3, F-14032 Caen (France); Chauveau, E. [CNRS/IN2P3, Centre d' Etudes Nucleaires de Bordeaux Gradignan, UMR 5797, F-33175 Gradignan (France); Universite de Bordeaux, Centre d' Etudes Nucleaires de Bordeaux Gradignan, UMR 5797, F-33175 Gradignan (France); Dafni, Th. [Instituto de Fisica Nuclear y Altas Energias, Universidad de Zaragoza, Zaragoza (Spain); Diaz, J. [Instituto de Fisica Corpuscular, CSIC, Universidad de Valencia, Valencia (Spain); Durand, D. [LPC Caen, ENSICAEN, Universite de Caen, CNRS/IN2P3, F-14032 Caen (France)

    2010-10-01

    The development of BiPo detectors is dedicated to the measurement of extremely high radiopurity in {sup 208}Tl and {sup 214}Bi for the SuperNEMO double beta decay source foils. A modular prototype, called BiPo-1, with 0.8 m{sup 2} of sensitive surface area, has been running in the Modane Underground Laboratory since February, 2008. The goal of BiPo-1 is to measure the different components of the background and in particular the surface radiopurity of the plastic scintillators that make up the detector. The first phase of data collection has been dedicated to the measurement of the radiopurity in {sup 208}Tl. After more than one year of background measurement, a surface activity of the scintillators of A({sup 208}Tl)=1.5{mu}Bq/m{sup 2} is reported here. Given this level of background, a larger BiPo detector having 12 m{sup 2} of active surface area, is able to qualify the radiopurity of the SuperNEMO selenium double beta decay foils with the required sensitivity of A({sup 208}Tl)<2{mu}Bq/kg (90% C.L.) with a six month measurement.

  5. Withaferin A disrupts ubiquitin-based NEMO reorganization induced by canonical NF-κB signaling

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Shawn S. [McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison, 6159 Wisconsin Institute for Medical Research, 1111 Highland Avenue, Madison, WI 53705 (United States); Medical Scientist Training Program, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705 (United States); Cellular and Molecular Biology Program, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705 (United States); Oberley, Christopher [McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison, 6159 Wisconsin Institute for Medical Research, 1111 Highland Avenue, Madison, WI 53705 (United States); Hooper, Christopher P. [McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison, 6159 Wisconsin Institute for Medical Research, 1111 Highland Avenue, Madison, WI 53705 (United States); Cellular and Molecular Biology Program, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705 (United States); Grindle, Kreg [Department of Medicine, Division of Hematology and Oncology, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705 (United States); Wuerzberger-Davis, Shelly [McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison, 6159 Wisconsin Institute for Medical Research, 1111 Highland Avenue, Madison, WI 53705 (United States); Wolff, Jared [Department of Medicine, Division of Hematology and Oncology, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705 (United States); and others

    2015-02-01

    The NF-κB family of transcription factors regulates numerous cellular processes, including cell proliferation and survival responses. The constitutive activation of NF-κB has also emerged as an important oncogenic driver in many malignancies, such as activated B-cell like diffuse large B cell lymphoma, among others. In this study, we investigated the impact and mechanisms of action of Withaferin A, a naturally produced steroidal lactone, against both signal-inducible as well as constitutive NF-κB activities. We found that Withaferin A is a robust inhibitor of canonical and constitutive NF-κB activities, leading to apoptosis of certain lymphoma lines. In the canonical pathway induced by TNF, Withaferin A did not disrupt RIP1 polyubiquitination or NEMO–IKKβ interaction and was a poor direct IKKβ inhibitor, but prevented the formation of TNF-induced NEMO foci which colocalized with TNF ligand. While GFP-NEMO efficiently formed TNF-induced foci, a GFP-NEMO{sup Y308S} mutant that is defective in binding to polyubiquitin chains did not form foci. Our study reveals that Withaferin A is a novel type of IKK inhibitor which acts by disrupting NEMO reorganization into ubiquitin-based signaling structures in vivo. - Highlights: • Withaferin A, a NF-κB inhibitor, disrupts signaling induced NEMO localization, a novel point of inhibition. • NEMO can be localized to distinct signaling foci after treatment with TNF. • ABC-type DLCBL cells can be sensitized to apoptosis after treatment with Withaferin A.

  6. Modeling of Direct Contact Wet Cooling Tower in ETRR-2

    International Nuclear Information System (INIS)

    El Khatib, H.H.; Ismail, A.L.; ElRefaie, M.E.

    2008-01-01

    The Egyptian Testing and Research Reactor no.2 (ETRR-2) was commissioned at 1997 with maximum power 22 MW for research purposes; an induced draft wet cooling tower (counter flow type) was putted in operation in 2003 instead of the first one. Investigations are achieved to evaluate cooling tower performance to guarantee that the cooling tower capable to dissipate heat generated in reactor core. Merkel and Poppe analysis was applied to simulate this cooling tower packing. Merkel analysis was applied to predict water outlet temperature from cooling tower and also to show the effect of ambient conditions on this temperature. Poppe analysis was applied to predict Merkel number which evaluate cooling tower. The Runge-Kutta numerical method was applied to solve the differential equations in this model and an engineering equation solver (EES) is the language used to model the cooling tower. This research illustrates that the cooling tower achieves good performance in various sever ambient condition at maximum operating condition of reactor power. The results show that at severe summer condition of wet bulb temperature equals 24 degree c and tower inlet temperature equals 37 degree c, the outlet water temperature equals 30.4 degree c from cooling tower, while the Merkel number is be found 1.253

  7. Double-beta decay measurement of 100Mo to the excited 01+ state of 100Ru in the NEMO3 experiment - R/D program for SuperNEMO: development of a BiPo detector to measure ultra low contaminations in the source foils

    International Nuclear Information System (INIS)

    Chapon, A.

    2011-10-01

    The NEMO3 detector was designed for the study of double beta decay and in particular the search for neutrinoless double beta decay (ββ0ν). The quantity of 100 Mo in the detector (7 kg) allows also a competitive measurement of the two-neutrino double beta decay (ββ2ν) of 100 Mo to the excited 0 1 + state of 100 Ru (eeNγ channel). Monte-Carlo simulations of the effect and of all the possible sources of background have been studied in order to determine their contributions to the full NEMO3 experimental data (2003-2011). These one have then been analysed: the ββ2ν decay half-life has been measured, and a limit on the ββ0ν decay has been obtained. Moreover, the SuperNEMO experiment aims to reach a sensitivity up to 10 26 years on the half-life of neutrinoless double beta decay. The SuperNEMO detector radioactivity has to be as low as possible. Especially radio-purity levels of 2 μBq*kg -1 in 208 Tl and 10 μBq*kg -1 in 214 Bi are required for the source foils. The gamma-spectrometry can not measure such low contamination levels. Hence, a BiPo dedicated detector has been developed to measure 208 Tl and 214 Bi contaminations, identifying the Bi→Po→Pb β-α chains. A proof of principle has been performed and the detector background has been measured. Assuming these values, a full BiPo detector of 3.6 m 2 can achieve the required sensitivities for the SuperNEMO source foils within six months of measurement. (author)

  8. NEMO educational kit on micro-optics at the secondary school

    Science.gov (United States)

    Flores-Arias, M. T.; Bao-Varela, Carmen

    2014-07-01

    NEMO was the "Network of Excellence in Micro-Optics" granted in the "Sixth Framework Program" of the European Union. It aimed at providing Europe with a complete Micro-Optics food-chain, by setting up centers for optical modeling and design; measurement and instrumentation; mastering, prototyping and replication; integration and packaging and reliability and standardization. More than 300 researchers from 30 groups in 12 countries participated in the project. One of the objectives of NEMO was to spread excellence and disseminate knowledge on micro-optics and micro-photonics. To convince pupils, already from secondary school level on, about the crucial role of light and micro-optics and the opportunities this combination holds, several partners of NEMO had collaborate to create this Educational Kit. In Spain the partner involved in this aim was the "Microoptics and GRIN Optics Group" at the University of Santiago of Compostela (USC). The educational kits provided to the Secondary School were composed by two plastic cards with the following microoptical element: different kinds of diffractive optical elements or DOES and refractive optical elements or ROEs namely arrays of micro-lenses. The kit also included a DVD with a handbook for performing the experiments as well as a laser pointer source. This kit was distributed free of charge in the countries with partners in NEMO. In particular in Spain was offered to around 200 Secondary School Centers and only 80 answered accepting evaluate the kit.

  9. Surface wave effects in the NEMO ocean model: Forced and coupled experiments

    Science.gov (United States)

    Breivik, Øyvind; Mogensen, Kristian; Bidlot, Jean-Raymond; Balmaseda, Magdalena Alonso; Janssen, Peter A. E. M.

    2015-04-01

    The NEMO general circulation ocean model is extended to incorporate three physical processes related to ocean surface waves, namely the surface stress (modified by growth and dissipation of the oceanic wavefield), the turbulent kinetic energy flux from breaking waves, and the Stokes-Coriolis force. Experiments are done with NEMO in ocean-only (forced) mode and coupled to the ECMWF atmospheric and wave models. Ocean-only integrations are forced with fields from the ERA-Interim reanalysis. All three effects are noticeable in the extratropics, but the sea-state-dependent turbulent kinetic energy flux yields by far the largest difference. This is partly because the control run has too vigorous deep mixing due to an empirical mixing term in NEMO. We investigate the relation between this ad hoc mixing and Langmuir turbulence and find that it is much more effective than the Langmuir parameterization used in NEMO. The biases in sea surface temperature as well as subsurface temperature are reduced, and the total ocean heat content exhibits a trend closer to that observed in a recent ocean reanalysis (ORAS4) when wave effects are included. Seasonal integrations of the coupled atmosphere-wave-ocean model consisting of NEMO, the wave model ECWAM, and the atmospheric model of ECMWF similarly show that the sea surface temperature biases are greatly reduced when the mixing is controlled by the sea state and properly weighted by the thickness of the uppermost level of the ocean model. These wave-related physical processes were recently implemented in the operational coupled ensemble forecast system of ECMWF.

  10. Review paper of gateway selection schemes for MANET of NEMO (MANEMO)

    International Nuclear Information System (INIS)

    Mahmood, Z; Hashim, A; Khalifa, O; Anwar, F; Hameed, S

    2013-01-01

    The fast growth of Internet applications brings with it new challenges for researchers to provide new solutions that guarantee better Internet access for mobile hosts and networks. The globally reachable, Home-Agent based, infrastructure Network Mobility (NEMO) and the local, multi-hop, and infrastructure-less Mobile Ad hoc Network (MANET) developed by Internet Engineering Task Force (IETF) support different topologies of the mobile networks. A new architecture was proposed by combining both topologies to obtain Mobile Ad Hoc NEMO (MANEMO). However, the integration of NEMO and MANET introduces many challenges such as network loops, sub-optimal route, redundant tunnel problem, absence of communication without Home Agent reachability, and exit router selection when multiple Exit Routers to the Internet exist. This paper aims to review the different proposed models that could be used to implement the gateway selection mechanism and it highlights the strengths as well as the limitations of these approaches

  11. Engineering photochemical smog through convection towers

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, S.; Prueitt, M.L.; Bossert, J.E.; Mroz, E.J.; Krakowski, R.A.; Miller, R.L. [Los Alamos National Lab., NM (United States); Jacobson, M.Z.; Turco, R.P. [Los Alamos National Lab., NM (United States)]|[Univ. of California, Los Angeles, CA (United States). Atmospheric Sciences Dept.

    1995-02-01

    Reverse convection towers have attracted attention as a medium for cleansing modern cities. Evaporation of an aqueous mist injected at the tower opening could generate electrical power by creating descent, and simultaneously scavenge unsightly and unhealthful particulates. The study offered here assesses the influence to tower water droplets on the photochemical component of Los Angeles type smog. The primary radical chain initiator OH is likely removed into aqueous phases well within the residence time of air in the tower, and then reacts away rapidly. Organics do not dissolve, but nighttime hydrolysis of N{sub 2}O{sub 5} depletes the nitrogen oxides. A lack of HOx would slow hydrocarbon oxidation and so also ozone production. Lowering of NOx would also alter ozone production rates, but the direction is uncertain. SO{sub 2} is available in sufficient quantities in some urban areas to react with stable oxidants, and if seawater were the source of the mist, the high pH would lead to fast sulfur oxidation kinetics. With an accommodation coefficient of 10{sup {minus}3}, however, ozone may not enter the aqueous phase efficiently. Even if ozone is destroyed or its production suppressed, photochemical recovery times are on the order of hours, so that tower processing must be centered on a narrow midday time window. The cost of building the number of structures necessary for this brief turnover could be prohibitive. The increase in humidity accompanying mist evaporation could be controlled with condensers, but might otherwise counteract visibility enhancements by recreating aqueous aerosols. Quantification of the divergent forcings convection towers must exert upon the cityscape would call for coupled three dimensional modeling of transport, microphysics, and photochemistry. 112 refs.

  12. AlignNemo: a local network alignment method to integrate homology and topology.

    Directory of Open Access Journals (Sweden)

    Giovanni Ciriello

    Full Text Available Local network alignment is an important component of the analysis of protein-protein interaction networks that may lead to the identification of evolutionary related complexes. We present AlignNemo, a new algorithm that, given the networks of two organisms, uncovers subnetworks of proteins that relate in biological function and topology of interactions. The discovered conserved subnetworks have a general topology and need not to correspond to specific interaction patterns, so that they more closely fit the models of functional complexes proposed in the literature. The algorithm is able to handle sparse interaction data with an expansion process that at each step explores the local topology of the networks beyond the proteins directly interacting with the current solution. To assess the performance of AlignNemo, we ran a series of benchmarks using statistical measures as well as biological knowledge. Based on reference datasets of protein complexes, AlignNemo shows better performance than other methods in terms of both precision and recall. We show our solutions to be biologically sound using the concept of semantic similarity applied to Gene Ontology vocabularies. The binaries of AlignNemo and supplementary details about the algorithms and the experiments are available at: sourceforge.net/p/alignnemo.

  13. NEMO 2 - Be aware: Wind and solar are coming

    Energy Technology Data Exchange (ETDEWEB)

    Lund, P. [Helsinki Univ. of Technology, Otaniemi (Finland)

    1996-12-31

    Finnish research and development is well placed with respect to new renewable energy technologies in that there exists considerable expertise in specialized areas. For example, over 20 % of all power transmission equipment and generators used in wind energy systems world-wide are manufactured in Finland, while advanced instruments for monitoring wind speed are also highly regarded internationally. Moreover, unique wind technology for complex windy and freezing conditions have been developed. Finland has a 10 % share in the European photovoltaic market, and has competitive advantages in photovoltaic systems and applications, thin film solar cells, and automated electronic controlling systems. A unique solar energy storage system based on hydrogen technology demonstrates skills on overcoming the summer-winter syndrome of large-scale solar energy utilization. The annual turnover of the Finnish industries on solar and wind energy has increased from 5 million ECU in 1988 to almost 50 million ECU in 1996. The national R and D and D from 1988 onwards has played an important role in this context. Most of the research and development into new and renewable energy technologies in Finland has been carried out through the Advanced New Energy Systems and Technologies Research Programme (NEMO2) of Tekes

  14. NEMO. Netherlands Energy demand MOdel. A top-down model based on bottom-up information

    International Nuclear Information System (INIS)

    Koopmans, C.C.; Te Velde, D.W.; Groot, W.; Hendriks, J.H.A.

    1999-06-01

    The title model links energy use to other production factors, (physical) production, energy prices, technological trends and government policies. It uses a 'putty-semiputty' vintage production structure, in which new investments, adaptations to existing capital goods (retrofit) and 'good-housekeeping' are discerned. Price elasticities are relatively large in the long term and small in the short term. Most predictions of energy use are based on either econometric models or on 'bottom-up information', i.e. disaggregated lists of technical possibilities for and costs of saving energy. Typically, one predicts more energy-efficiency improvements using bottom-up information than using econometric ('top-down') models. We bridged this so-called 'energy-efficiency gap' by designing our macro/meso model NEMO in such a way that we can use bottom-up (micro) information to estimate most model parameters. In our view, reflected in NEMO, the energy-efficiency gap arises for two reasons. The first is that firms and households use a fairly high discount rate of 15% when evaluating the profitability of energy-efficiency improvements. The second is that our bottom-up information ('ICARUS') for most economic sectors does not (as NEMO does) take account of the fact that implementation of new, energy-efficient technology in capital stock takes place only gradually. Parameter estimates for 19 sectors point at a long-term technological energy efficiency improvement trend in Netherlands final energy use of 0.8% per year. The long-term price elasticity is estimated to be 0.29. These values are comparable to other studies based on time series data. Simulations of the effects of the oil price shocks in the seventies and the subsequent fall of oil prices show that the NEMO's price elasticities are consistent with historical data. However, the present pace at which new technologies become available (reflected in NEMO) appears to be lower than in the seventies and eighties. This suggests that it

  15. Heat transfer during phase change. Evaporation. Application to cooling towers

    International Nuclear Information System (INIS)

    Merigoux, J.

    1973-01-01

    Evaporation near a water sheet, without convection, is considered. The displacement of water molecules in the gaseous phase, due to concentration gradients, is especially studied. This displacement governs the development of evaporation. The calculation is made to derive the velocity of water evaporation as a function of the partial pressure of the surrounding air, the temperature and physical properties of the air and steam. Diffusion laws are used. The calculation is applied to cooling towers, according to Merkel theory [fr

  16. Study of tracking detector of NEMO3 experiment - simulation of the measurement of the ultra low {sup 208}Tl radioactivity in the source foils used as neutrinoless double beta decay emitters in NEMO3 experiment; Etude du detecteur de traces de l'experience NEMO3. Simulation de la mesure de l'ultra-faible radioactivite en {sup 208}Tl des sources de l'experience NEMO3 candidates a la double desintegration {beta} sans emission de neutrino

    Energy Technology Data Exchange (ETDEWEB)

    Errahmane, K

    2001-04-01

    The purpose of NEMO3 experiment is the research of the neutrinoless double beta decay. This low energy process can sign the massive and Majorana nature of neutrino. This experiment, with a very low radioactive background and containing 10 kg of enriched isotopes, studies mainly {sup 100}Mo. Installed at the Frejus underground laboratory, NEMO3 is a cylindrical detector, which consists in very thin central source foils, in a tracking detector made up of vertical drift cells operating in Geiger mode, in a calorimeter and in a suitable shielding. This thesis is divided in two different parts. The first part is a full study of the features of the tracking detector. With a prototype composed of 9 drift cells, we characterised the longitudinal and transverse reconstruction of position of the ionisation created by a LASER. With the first 3 modules under operation, we used radioactive external neutron sources to measure the transverse resolution of ionisation position in a drift cell for high energy electrons. To study the vertex reconstruction on the source foil, sources of {sup 207}Bi, which produced conversion electrons, were used inside the 3 modules. The second part of this thesis, we show, with simulations, that we can measure, with NEMO3 detector itself, the ultra low level of contamination in {sup 208}Tl of the source foil, which comes from the natural radioactive chain of thorium. Using electron-photons channels, we can obtain the {sup 208}Tl activity in the sources. With an analysis on the energy and on the time of flight of particles, NEMO3 is able to reach a sensitivity of 20{mu}Bq/kg after only 2 months of measurement. This sensitivity is the maximum {sup 208}Tl activity, which we accepted for the sources in the NEMO3 proposal. (author)

  17. Radon emanation chamber: High sensitivity measurements for the SuperNEMO experiment

    Energy Technology Data Exchange (ETDEWEB)

    Soulé, B. [Université Bordeaux 1, Centre d' Etudes Nucléaires de Bordeaux Gradignan, UMR 5797, Chemin du Solarium, Le Haut-Vigneau, BP120, F-33175 Gradignan (France); Collaboration: SuperNEMO Collaboration; and others

    2013-08-08

    Radon is a well-known source of background in ββ0ν experiments due to the high Q{sub β} value of one of its daughter nucleus, {sup 214}Bi. The SuperNEMO collaboration requires a maximum radon contamination of 0.1 mBq/m{sup 3} inside its next-generation double beta decay detector. To reach such a low activity, a drastic screening process has been set for the selection of the detector's materials. In addition to a good radiopurity, a low emanation rate is required. To test this parameter, a Radon Emanation Setup is running at CENBG. It consists in a large emanation chamber connected to an electrostatic detector. By measuring large samples and having a low background level, this setup reaches a sensitivity of a few μ Bq. m{sup −2}. d{sup −1} and is able to qualify materials used in the construction of the SuperNEMO detector.

  18. Sea-ice evaluation of NEMO-Nordic 1.0: a NEMO-LIM3.6-based ocean-sea-ice model setup for the North Sea and Baltic Sea

    Science.gov (United States)

    Pemberton, Per; Löptien, Ulrike; Hordoir, Robinson; Höglund, Anders; Schimanke, Semjon; Axell, Lars; Haapala, Jari

    2017-08-01

    The Baltic Sea is a seasonally ice-covered marginal sea in northern Europe with intense wintertime ship traffic and a sensitive ecosystem. Understanding and modeling the evolution of the sea-ice pack is important for climate effect studies and forecasting purposes. Here we present and evaluate the sea-ice component of a new NEMO-LIM3.6-based ocean-sea-ice setup for the North Sea and Baltic Sea region (NEMO-Nordic). The setup includes a new depth-based fast-ice parametrization for the Baltic Sea. The evaluation focuses on long-term statistics, from a 45-year long hindcast, although short-term daily performance is also briefly evaluated. We show that NEMO-Nordic is well suited for simulating the mean sea-ice extent, concentration, and thickness as compared to the best available observational data set. The variability of the annual maximum Baltic Sea ice extent is well in line with the observations, but the 1961-2006 trend is underestimated. Capturing the correct ice thickness distribution is more challenging. Based on the simulated ice thickness distribution we estimate the undeformed and deformed ice thickness and concentration in the Baltic Sea, which compares reasonably well with observations.

  19. A modeling and experimental study of flue gas desulfurization in a dense phase tower

    International Nuclear Information System (INIS)

    Chang, Guanqin; Song, Cunyi; Wang, Li

    2011-01-01

    We used a dense phase tower as the reactor in a novel semi-dry flue gas desulfurization process to achieve a high desulfurization efficiency of over 95% when the Ca/S molar ratio reaches 1.3. Pilot-scale experiments were conducted for choosing the parameters of the full-scale reactor. Results show that with an increase in the flue gas flow rate the rate of the pressure drop in the dense phase tower also increases, however, the rate of the temperature drop decreases in the non-load hot gas. We chose a water flow rate of 0.6 kg/min to minimize the approach to adiabatic saturation temperature difference and maximize the desulfurization efficiency. To study the flue gas characteristics under different processing parameters, we simulated the desulfurization process in the reactor. The simulated data matched very well with the experimental data. We also found that with an increase in the Ca/S molar ratio, the differences between the simulation and experimental data tend to decrease; conversely, an increase in the flue gas flow rate increases the difference; this may be associated with the surface reactions caused by collision, coalescence and fragmentation between the dispersed phases.

  20. Study of the background of the neutrinoless double {beta} decay with the detector NEMO 2: contribution arising from the radon diffusion and internal pollution of the source {sup 214}Bi have been estimated; Etude du bruit de fond de la double-desintegration {beta} sans emission de neutrino dans le detecteur NEMO 2: contribution du radon ambiant et mesure de la pollution interne de la source en {sup 214}Bi

    Energy Technology Data Exchange (ETDEWEB)

    Mauger, F.

    1995-02-01

    The NEMO experiment is designed to understand the nature of the neutrino by studying the double beta decay of Mo-100 which is related to the Majorana neutrino effective mass. In this kind of experiment a good understanding of the different sources of background is crucial as only few events are expected per year at the required level of sensitivity. In this thesis we present the main theoretical and experimental aspects of the measurement of the neutrinoless double beta decay of Mo-100 with the prototype detector NEMO2. The goal of this study is to obtain a realistic interpretation of the few events detected at high energy in the two-electron channel as a background to neutrinoless double beta decay. In particular, the contribution arising from Bi-214 has been investigated. These events have been selected and analysed by means of the beta-alpha decays of Bi-214 into Pb-210. The events are characterized by a delayed track in the wire chamber and the corresponding signal is rather clean. The study has demonstrated the diffusion of Rn-222 into the detector and its contribution to Bi-214 pollution has been estimated. A measurement of the Bi-214 internal contamination of the source has been made as well as an estimation of the Bi-214 deposit due to Rn-222. As a result of this study it appears that, under the conditions of the NEMO2 experiment, the Bi and Rn contributions are of the same order of magnitude as the background induced at high energy by two-neutrino double beta decay. In conclusion, the backgrounds of the neutrinoless double beta decay of Mo-100 are well understood in the NEMO2 experiment leading to an extrapolation for the NEMO3 experiment. (authors).

  1. Solar tower enhanced natural draft dry cooling tower

    Science.gov (United States)

    Yang, Huiqiang; Xu, Yan; Acosta-Iborra, Alberto; Santana, Domingo

    2017-06-01

    Concentrating Solar Power (CSP) plants are located in desert areas where the Direct Normal Irradiance (DNI) value is very high. Since water resource is scarcely available, mechanical draft cooing technology is commonly used, with power consumption of mechanical fans being approximately 2% of the total power generated. Today, there is only one solar power plant (Khi Solar One in South Africa) uses a condenser installed in a Natural Draft Cooling (NDC) tower that avoids the windage loss of water occurring in wet cooling towers. Although, Khi Solar One is a cavity receiver power tower, the receivers can be hung onto the NDC tower. This paper looks at a novel integration of a NDC tower into an external molten salt receiver of a solar power plant, which is one of a largest commercial molten salt tower in China, with 100MWe power capacity. In this configuration study, the NDC tower surrounds the concrete tower of the receiver concentrically. In this way, the receiver concrete tower is the central support of the NDC tower, which consists of cable networks that are fixed to the concrete tower and suspended at a certain height over the floor. The cable networks support the shell of the NDC tower. To perform a preliminary analysis of the behavior of this novel configuration, two cases of numerical simulation in three dimensional (3D) models have been solved using the commercial Computational Fluid Dynamics (CFD) code, ANSYS Fluent 6.3. The results show that the integration of the NDC tower into an external central receiver tower is feasible. Additionally, the total heat transfer rate is not reduced but slightly increases when the molten salt receiver is in operation because of the additional natural draft induced by the high temperature of the receiver.

  2. NEMO-SN-1 the first 'real-time' seafloor observatory of ESONET

    International Nuclear Information System (INIS)

    Favali, Paolo; Beranzoli, Laura; D'Anna, Giuseppe; Gasparoni, Francesco; Gerber, Hans W.

    2006-01-01

    The fruitful collaboration between Italian Research Institutions, particularly Istituto Nazionale di Fisica Nucleare (INFN) and Istituto Nazionale di Geofisica e Vulcanologia (INGV) together with Marine Engineering Companies, led to the development of NEMO-SN-1, the first European cabled seafloor multiparameter observatory. This observatory, deployed at 2060 m w.d. about 12 miles off-shore the Eastern coasts of Sicily (Southern Italy), is in real-time acquisition since January 2005 and addressed to different set of measurements: geophysical and oceanographic. In particular the SN-1 seismological data are integrated in the INGV land-based national seismic network, and they arrive in real-time to the Operative Centre in Rome. In the European Commission (EC) European Seafloor Observatory NETwork (ESONET) project, in connection to the Global Monitoring for Environment and Security (GMES) action plan, the NEMO-SN-1 site has been proposed as an European key area, both for its intrinsic importance for geo-hazards and for the availability of infrastructure as a stepwise development in GMES program. Presently, NEMO-SN-1 is the only ESONET site operative. The paper gives a description of SN-1 observatory with examples of data

  3. NBodyLab: A Testbed for Undergraduates Utilizing a Web Interface to NEMO and MD-GRAPE2 Hardware

    Science.gov (United States)

    Johnson, V. L.; Teuben, P. J.; Penprase, B. E.

    An N-body simulation testbed called NBodyLab was developed at Pomona College as a teaching tool for undergraduates. The testbed runs under Linux and provides a web interface to selected back-end NEMO modeling and analysis tools, and several integration methods which can optionally use an MD-GRAPE2 supercomputer card in the server to accelerate calculation of particle-particle forces. The testbed provides a framework for using and experimenting with the main components of N-body simulations: data models and transformations, numerical integration of the equations of motion, analysis and visualization products, and acceleration techniques (in this case, special purpose hardware). The testbed can be used by students with no knowledge of programming or Unix, freeing such students and their instructor to spend more time on scientific experimentation. The advanced student can extend the testbed software and/or more quickly transition to the use of more advanced Unix-based toolsets such as NEMO, Starlab and model builders such as GalactICS. Cosmology students at Pomona College used the testbed to study collisions of galaxies with different speeds, masses, densities, collision angles, angular momentum, etc., attempting to simulate, for example, the Tadpole Galaxy and the Antenna Galaxies. The testbed framework is available as open-source to assist other researchers and educators. Recommendations are made for testbed enhancements.

  4. Determination of the replacement cooling tower capability at the ETRR-2 research reactor

    International Nuclear Information System (INIS)

    El-Din El-Morshdy, S.

    2004-01-01

    The ETRR-2 replacement cooling tower capability has been evaluated by the thermal acceptance test performed in June 2003. All instruments used were calibrated prior to the test. The measured data are collected at regular intervals in accordance with the acceptance test code for water cooling towers of the cooling tower institute recommendations. Both the characteristic curve and the performance curve methods were used to evaluate the tower capability. The test results yield a tower capability of about 105% and so the tower is thermally accepted. (orig.)

  5. X-ray Observations at Gaisberg Tower

    Directory of Open Access Journals (Sweden)

    Pasan Hettiarachchi

    2018-01-01

    Full Text Available We report the occurrence of X-rays at ground level due to cloud-to-ground flashes of upward-initiated lightning from Gaisberg Tower, in Austria, which is located at an altitude of 1300 m. This is the first observation of X-ray emissions from upward lightning from a tower top located at high altitude. Measurements were carried out using scintillation detectors installed close to the tower top in two phases from 2011 to 2015. X-rays were recorded in three subsequent strokes of three flashes out of the total of 108 flashes recorded in the system during both phases. In contrast to the observations from downward natural or triggered lightning, X-rays were observed only within 10 µs before the subsequent return stroke. This shows that X-rays were emitted when the dart leader was in the vicinity of the tower top, hence during the most intense phase of the dart leader. Both the detected energy and the fluence of X-rays are far lower compared to X-rays from downward natural or rocket-triggered lightning. In addition to the above 108 flashes, an interesting observation of X-rays produced by a nearby downward flash is also presented. The shorter length of dart-leader channels in Gaisberg is suggested as a possible cause of this apparently weaker X-ray production.

  6. Nemo-3 calorimeter electronics

    International Nuclear Information System (INIS)

    Bernaudin, P.; Cheikali, C.; Lavigne, B.; Richard, A.; Lebris, J.

    2000-11-01

    The calorimeter electronics of the NEMO-3 double beta decay experiment fulfills three functions: -energy measurement of the electrons by measuring the charge of the pulses, - time measurement, - fast first level triggering. The electronics of the 1940 Scintillator-PM modules is implemented as 40 '9U x 400 mm VME' boards of up to 51 channels. For each channel the analog signals conditioning is implemented as one SMD daughter board. Each board performs 12 bit charge measurements with 0.35 pC charge resolution, 12 bit time measurements with 50 ps time resolution and a fast analog multiplicity level for triggering. The total handling and conversion time for all the channels is less than 100 μs. The electronics will be presented as well as the test system. (authors)

  7. Novel hypomorphic mutation in IKBKG impairs NEMO-ubiquitylation causing ectodermal dysplasia, immunodeficiency, incontinentia pigmenti, and immune thrombocytopenic purpura.

    Science.gov (United States)

    Ramírez-Alejo, Noé; Alcántara-Montiel, Julio C; Yamazaki-Nakashimada, Marco; Duran-McKinster, Carola; Valenzuela-León, Paola; Rivas-Larrauri, Francisco; Cedillo-Barrón, Leticia; Hernández-Rivas, Rosaura; Santos-Argumedo, Leopoldo

    2015-10-01

    NF-κB essential modulator (NEMO) is a component of the IKK complex, which participates in the activation of the NF-κB pathway. Hypomorphic mutations in the IKBKG gene result in different forms of anhidrotic ectodermal dysplasia with immunodeficiency (EDA-ID) in males without affecting carrier females. Here, we describe a hypomorphic and missense mutation, designated c.916G>A (p.D306N), which affects our patient, his mother, and his sister. This mutation did not affect NEMO expression; however, an immunoprecipitation assay revealed reduced ubiquitylation upon CD40-stimulation in the patient's cells. Functional studies have demonstrated reduced phosphorylation and degradation of IκBα, affecting NF-κB recruitment into the nucleus. The patient presented with clinical features of ectodermal dysplasia, immunodeficiency, and immune thrombocytopenic purpura, the latter of which has not been previously reported in a patient with NEMO deficiency. His mother and sister displayed incontinentia pigmenti indicating that, in addition to amorphic mutations, hypomorphic mutations in NEMO can affect females. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Cooling tower calculations

    International Nuclear Information System (INIS)

    Simonkova, J.

    1988-01-01

    The problems are summed up of the dynamic calculation of cooling towers with forced and natural air draft. The quantities and relations are given characterizing the simultaneous exchange of momentum, heat and mass in evaporative water cooling by atmospheric air in the packings of cooling towers. The method of solution is clarified in the calculation of evaporation criteria and thermal characteristics of countercurrent and cross current cooling systems. The procedure is demonstrated of the calculation of cooling towers, and correction curves and the effect assessed of the operating mode at constant air number or constant outlet air volume flow on their course in ventilator cooling towers. In cooling towers with the natural air draft the flow unevenness is assessed of water and air relative to its effect on the resulting cooling efficiency of the towers. The calculation is demonstrated of thermal and resistance response curves and cooling curves of hydraulically unevenly loaded towers owing to the water flow rate parameter graded radially by 20% along the cross-section of the packing. Flow rate unevenness of air due to wind impact on the outlet air flow from the tower significantly affects the temperatures of cooled water in natural air draft cooling towers of a design with lower demands on aerodynamics, as early as at wind velocity of 2 m.s -1 as was demonstrated on a concrete example. (author). 11 figs., 10 refs

  9. Naval EarthMap Observer (NEMO) science and naval products

    Science.gov (United States)

    Davis, Curtiss O.; Kappus, Mary E.; Gao, Bo-Cai; Bissett, W. Paul; Snyder, William A.

    1998-11-01

    A wide variety of applications of imaging spectrometry have been demonstrated using data from aircraft systems. Based on this experience the Navy is pursuing the Hyperspectral Remote Sensing Technology (HRST) Program to use hyperspectral imagery to characterize the littoral environment, for scientific and environmental studies and to meet Naval needs. To obtain the required space based hyperspectral imagery the Navy has joined in a partnership with industry to build and fly the Naval EarthMap Observer (NEMO). The NEMO spacecraft has the Coastal Ocean Imaging Spectrometer (COIS) a hyperspectral imager with adequate spectral and spatial resolution and a high signal-to- noise ratio to provide long term monitoring and real-time characterization of the coastal environment. It includes on- board processing for rapid data analysis and data compression, a large volume recorder, and high speed downlink to handle the required large volumes of data. This paper describes the algorithms for processing the COIS data to provide at-launch ocean data products and the research and modeling that are planned to use COIS data to advance our understanding of the dynamics of the coastal ocean.

  10. Analysis of the data from the NEMO3 experiment and search for neutrinoless double beta decay - Study of systematic bias of the calorimeter and development of analysis tools

    International Nuclear Information System (INIS)

    Hugon, C.

    2012-11-01

    The NEMO3 experiment was researching the neutrinoless double-β (0ndb) decay by using various sources of double beta decay isotopes (mainly 100 Mo, 82 Se, 116 Cd and 130 Te for about 10 kg in total). The detector was located in the underground laboratory of Modane (Italy) in the halfway point of the Frejus tunnel. This experiment demonstrated that the 'tracko-calo' technology is really competitive and, in addition, it gives new results for the 2-neutrinos double-β (2ndb) decay and the (0ndb) decays research. Moreover it opened an new way for its successor SuperNEMO, which aim is to reach a mass of 100 kg of 82 Se (for a sensitivity of 10 26 years). The main goal of the thesis is to measure the 2ndb and 0ndb decay of the 100 Mo to the excited state 0 1 + of the 100 Ru thanks to the whole NEMO3 data, with new original methods of analysis and through the development of the collaboration analysis software. The results obtained for the ground states (gs) and excited states 2ndb of the 100 Mo are for the half-lives: T(2nbd, gs)=[7.05±0.01(stat)±0.54(syst)]*10 18 years and T(2ndb, 0 1 + )=[6.15±1.1(sta)±0.78]*10 20 years. Those results are compatibles with the last ones published by the collaboration. For the 0ndb(0 1 + ), this work gave a half-life of T(0ndb, 0 1 + ) > 2.6*10 23 years, improving significantly the last published results. Furthermore those methods also allowed to present a new and more exhaustive background noise model for this experiment. The second point of this work was to measure the systematics errors of the NEMO3 calorimeter, among others due to the wavelength of the NEMO3 calibration systems. This work was done using a new test bench based on LED. This bench also allowed to contribute to the development of the SuperNEMO calorimeter, especially in the time characteristic and the energy linearity measurement of the photomultiplier intended to the demonstrator of the experiments. (author)

  11. Evaluation of QoS supported in Network Mobility NEMO environments

    International Nuclear Information System (INIS)

    Hussien, L F; Abdalla, A H; Habaebi, M H; Khalifa, O O; Hassan, W H

    2013-01-01

    Network mobility basic support (NEMO BS) protocol is an entire network, roaming as a unit which changes its point of attachment to the Internet and consequently its reachability in the network topology. NEMO BS doesn't provide QoS guarantees to its users same as traditional Internet IP and Mobile IPv6 as well. Typically, all the users will have same level of services without considering about their application requirements. This poses a problem to real-time applications that required QoS guarantees. To gain more effective control of the network, incorporated QoS is needed. Within QoS-enabled network the traffic flow can be distributed to various priorities. Also, the network bandwidth and resources can be allocated to different applications and users. Internet Engineering Task Force (IETF) working group has proposed several QoS solutions for static network such as IntServ, DiffServ and MPLS. These QoS solutions are designed in the context of a static environment (i.e. fixed hosts and networks). However, they are not fully adapted to mobile environments. They essentially demands to be extended and adjusted to meet up various challenges involved in mobile environments. With existing QoS mechanisms many proposals have been developed to provide QoS for individual mobile nodes (i.e. host mobility). In contrary, research based on the movement of the whole mobile network in IPv6 is still undertaking by the IETF working groups (i.e. network mobility). Few researches have been done in the area of providing QoS for roaming networks. Therefore, this paper aims to review and investigate (previous /and current) related works that have been developed to provide QoS in mobile network. Consequently, a new proposed scheme will be introduced to enhance QoS within NEMO environment, achieving by which seamless mobility to users of mobile network node (MNN)

  12. Noise emissions of cooling towers; Geraeuschemissionen von Kuehltuermen

    Energy Technology Data Exchange (ETDEWEB)

    Hinkelmann, Dirk [Mueller-BBM GmbH, Gelsenkirchen (Germany)

    2013-09-01

    Cooling towers are often large structures with high sound emission. The impact of water drops on the water surface in the collecting basin leads to the generation of middle- and high-frequency noise that is emitted via the air intake opening and the outlet. In forced-draft cooling towers, additional noise is generated by drives and fans. The sound emissions can be predicted by means of empirical calculation models. In this way, noise control measures can be taken into account already at an early phase of planning. Different, proven measures for reduction of sound emissions are taken depending on cooling tower design. Regulations on noise acceptance testing for cooling towers are given in various standards. (orig.)

  13. Evaluation of the coupled COSMO-CLM+NEMO-Nordic model with focus on North and Baltic seas

    Science.gov (United States)

    Lenhardt, J.; Pham, T. V.; Früh, B.; Brauch, J.

    2017-12-01

    The region east of the Baltic Sea has been identified as a hot-spot of climate change by Giorgi, 2006, on the base of temperature and precipitation variability. For this purpose, the atmosphere model COSMO-CLM has been coupled to the ocean model NEMO, including the sea ice model LIM3, via the OASIS3-MCT coupler (Pham et al., 2014). The coupler interpolates heat, fresh water, momentum fluxes, sea level pressure and the fraction of sea ice at the interface in space and time. Our aim is to find an optimal configuration of the already existing coupled regional atmospheric-ocean model COSMO-CLM+NEMO-Nordic. So far results for the North- and Baltic seas show that the coupled run has large biases compared with the E-OBS reference data. Therefore, additional simulation evaluations are planned by the use of independent satellite observation data (e.g. Copernicus, EURO4M). We have performed a series of runs with the coupled COSMO-CLM+NEMO-Nordic model to find out about differences of model outputs due to different coupling time steps. First analyses of COSMO-CLM 2m temperatures let presume that different coupling time steps have an impact on the results of the coupled model run. Additional tests over a longer period of time are conducted to understand whether the signal-to-noise ratio could influence the bias. The results will be presented in our poster.

  14. A Spectrum Handoff Scheme for Optimal Network Selection in NEMO Based Cognitive Radio Vehicular Networks

    Directory of Open Access Journals (Sweden)

    Krishan Kumar

    2017-01-01

    Full Text Available When a mobile network changes its point of attachments in Cognitive Radio (CR vehicular networks, the Mobile Router (MR requires spectrum handoff. Network Mobility (NEMO in CR vehicular networks is concerned with the management of this movement. In future NEMO based CR vehicular networks deployment, multiple radio access networks may coexist in the overlapping areas having different characteristics in terms of multiple attributes. The CR vehicular node may have the capability to make call for two or more types of nonsafety services such as voice, video, and best effort simultaneously. Hence, it becomes difficult for MR to select optimal network for the spectrum handoff. This can be done by performing spectrum handoff using Multiple Attributes Decision Making (MADM methods which is the objective of the paper. The MADM methods such as grey relational analysis and cost based methods are used. The application of MADM methods provides wider and optimum choice among the available networks with quality of service. Numerical results reveal that the proposed scheme is effective for spectrum handoff decision for optimal network selection with reduced complexity in NEMO based CR vehicular networks.

  15. Correlating interleukin-12 stimulated interferon-γ production and the absence of ectodermal dysplasia and anhidrosis (EDA) in patients with mutations in NF-κB essential modulator (NEMO).

    Science.gov (United States)

    Haverkamp, Margje H; Marciano, Beatriz E; Frucht, David M; Jain, Ashish; van de Vosse, Esther; Holland, Steven M

    2014-05-01

    Patients with hypomorphic mutations in Nuclear Factor-κB Essential Modulator (NEMO) are immunodeficient (ID) and most display ectodermal dysplasia and anhidrosis (EDA). We compared cytokine production by NEMO-ID patients with and without EDA. PBMCs of NEMO-ID patients, four with EDA carrying E315A, C417R, D311N and Q403X, and three without EDA carrying E315A, E311_L333del and R254G, were cultured with PHA, PHA plus IL-12p70, LPS, LPS plus IFN-γ, TNF and IL-1β. The production of various cytokines was measured in the supernatants. Fifty-nine healthy individuals served as controls. PBMCs of NEMO-ID patients without EDA produce subnormal amounts of IFN-γ after stimulation with PHA, but normal amounts of IFN-γ after PHA plus IL-12p70. In contrast, IFN-γ production by patients with EDA was low in both cases. Patients with EDA also generate lower PHA-stimulated IL-10 and IL-1β than controls, whereas the production of these cytokines by patients without EDA was normal. Responses of PBMCs in NEMO-ID patients with EDA to PHA with and without IL-12p70 appear less robust than in NEMO-ID patients without EDA. This possibly indicates a better preserved NEMO function in our patients without EDA.

  16. Cooling towers

    International Nuclear Information System (INIS)

    Korik, L.; Burger, R.

    1992-01-01

    What is the effect of 0.6C (1F) temperature rise across turbines, compressors, or evaporators? Enthalpy charts indicate for every 0.6C (1F) hotter water off the cooling tower will require an additional 2 1/2% more energy cost. Therefore, running 2.2C (4F) warmer due to substandard cooling towers could result in a 10% penalty for overcoming high heads and temperatures. If it costs $1,250,000.00 a year to operate the system, $125,000.00 is the energy penalty for hotter water. This paper investigates extra fuel costs involved in maintaining design electric production with cooling water 0.6C (1F) to 3C (5.5F) hotter than design. If design KWH cannot be maintained, paper will calculate dollar loss of saleable electricity. The presentation will conclude with examining the main causes of deficient cold water production. State-of-the-art upgrading and methodology available to retrofit existing cooling towers to optimize lower cooling water temperatures will be discussed

  17. Transporting method for adsorbing tower and the adsorbing tower

    International Nuclear Information System (INIS)

    Shimokawa, Nobuhiro.

    1996-01-01

    A cylindrical plastic bag is disposed to the upper surface of an adsorbing tower so as to surround a suspending piece. One opening of the bag is sealed, and other opening is secured in a sealed state to a bag holding portion disposed to glove box at a gate for the adsorbing tower box. The adsorbing tower is transported into the glove box, and after the completion of the operation of the adsorbing tower, the adsorbing tower is taken out in a state that the bag is restricted and sealed at a portion below the adsorbing tower. The bag may be made of a vinyl plastic, the bag holding portion may be a short-cylindrical protrusion, and may have an O-ring groove at the outer surface. Even if the adsorbing tower is heavy, the adsorbing tower can be carried out easily in a state where it is sealed gas tightly. (N.H.)

  18. Update on the Purdue University 2-second Drop Tower

    Science.gov (United States)

    Collicott, Steven

    A small drop tower of approximately one second drop duration was built in the School of Aero-nautics and Astronautics at Purdue University beginning in 1998 and operated until summer 2007. This inexpensive tower in an old airplane hanger, was built largely by Yongkang Chen, now a Research Professor at Portland State University in Oregon, USA. In about 7 years of operations, the tower generated sufficient science results for Chen's PhD thesis[1] (summarized in three AIAA Journal papers[2-4]), Fitzpatrick's MS thesis[5], two industry projects for since-canceled advanced rodent habitats for ISS, and one project for NASA Marshall. In addition to the science use, Purdue undergraduate students designed, built, and performed simpler fluids experiments for their own career advancement, including a novel investigation of the impact of imperfect repeatability of initial conditions on a zero-g fluids experiment. The tower was also used for outreach to school children. It is most satisfying that Chen's PhD research in this small tower, and subsequent discussions and interactions, helped Weislogel to propose the two Vane Gap tests in his highly successful Capillary Fluids Experiment (CFE) in the International Space Station in 2006 and 2007[6]. Chen as been involved in the remodeling of these two Vane Gap cylinders for subsequent re-launch to ISS for a second round of experiments expected in 2010 and 2011. In August 2007 the School of Aeronautics and Astronautics at Purdue University moved into the new Neil Armstrong Hall of Engineering and construction on a new 2-second drop tower began. A vertical shaft of nearly 23 meters was designed into the building. An approximately 80 m2 general-use fluids lab is at the top level, and a small access room of approximately 9 m2 is at the bottom. However, construction of the new $57M building created only the space for the science facility, not the science facility itself. The science facility is under construction and this paper presents

  19. Updating of a finite element model of the Cruas 2 cooling tower

    International Nuclear Information System (INIS)

    Billet, L.

    1994-03-01

    A method based on modal analysis and inversion of a dynamic FEM model is used to detect changes in the dynamic behavior of nuclear plant cooling towers. Prior to detection, it is necessary to build a representative model of the structure. In this paper are given details about the CRUAS N. 2 cooling tower modelling and the updating procedure used to match the model to on-site measurements. First, were reviewed previous numerical and experimental studies on cooling towers vibrations. We found that the first eigenfrequencies of cooling towers are very sensitive to boundary conditions at the top and the bottom of the structure. Then, we built a beam and plate FEM model of the CRUAS N. 2 cooling tower. The first calculated modes were located in the proper frequency band (0.9 Hz - 1.30 Hz) but not distributed according to the experimental order. We decided to update the numerical model with MADMACS, an updating model software. It was necessary to: - decrease the shell stiffness by 30%; - increase the top ring stiffness by 300%; - modify the boundary conditions at the bottom by taking into account the soil impedance. In order to obtain a difference between the measured and the corresponding calculated frequencies less than 1%. The model was then judged to be realistic enough. (author). 23 figs., 13 refs., 1 annex

  20. Numerical Simulation of Wind Turbine Blade-Tower Interaction

    Institute of Scientific and Technical Information of China (English)

    Qiang Wang; Hu Zhou; Decheng Wan

    2012-01-01

    Numerical simulations of wind turbine blade-tower interaction by using the open source OpenFOAM tools coupled with arbitrary mesh interface (AMI) method were presented.The governing equations were the unsteady Reynolds-averaged Navier-Stokes (PANS) which were solved by the pimpleDyMFoam solver,and the AMI method was employed to handle mesh movements.The National Renewable Energy Laboratory (NREL) phase Ⅵ wind turbine in upwind configuration was selected for numerical tests with different incoming wind speeds (5,10,15,and 25 m/s) at a fixed blade pitch and constant rotational speed.Detailed numerical results of vortex structure,time histories of thrust,and pressure distribution on the blade and tower were presented.The findings show that the wind turbine tower has little effect on the whole aerodynamic performance of an upwind wind turbine,while the rotating rotor will induce an obvious cyclic drop in the front pressure of the tower.Also,strong interaction of blade tip vortices with separation from the tower was observed.

  1. Tower Based Load Measurements for Individual Pitch Control and Tower Damping of Wind Turbines

    International Nuclear Information System (INIS)

    Kumar, A A; Hugues-Salas, O; Savini, B; Keogh, W

    2016-01-01

    The cost of IPC has hindered adoption outside of Europe despite significant loading advantages for large wind turbines. In this work we presented a method for applying individual pitch control (including for higher-harmonics) using tower-top strain gauge feedback instead of blade-root strain gauge feedback. Tower-top strain gauges offer hardware savings of approximately 50% in addition to the possibility of easier access for maintenance and installation and requiring a less specialised skill-set than that required for applying strain gauges to composite blade roots. A further advantage is the possibility of using the same tower-top sensor array for tower damping control. This method is made possible by including a second order IPC loop in addition to the tower damping loop to reduce the typically dominating 3P content in tower-top load measurements. High-fidelity Bladed simulations show that the resulting turbine spectral characteristics from tower-top feedback IPC and from the combination of tower-top IPC and damping loops largely match those of blade-root feedback IPC and nacelle- velocity feedback damping. Lifetime weighted fatigue analysis shows that the methods allows load reductions within 2.5% of traditional methods. (paper)

  2. Investigations Of Powder Tower Of Daugavgriva's Fortress For Restoration

    International Nuclear Information System (INIS)

    Vitina, I.; Igaune, S.; Sidraba, I.

    2007-01-01

    The Powder Tower is one of the oldest, interesting and mysterious buildings located in the Northern part of Daugavgriva's fortress. Daugavgriva's fortress was built by Swedish army in the 17th century. The Powder Tower is a unique Monument of Cultural Heritage constructed mainly of dolomites and bricks cemented by lime mortar. Scientific investigations of stone materials and corrosion products of the Powder Tower were carried out at the laboratory of Centre for Conservation and Restoration of Stone Materials of Riga Technical University in order to characterise authentic materials and elaborate conservation plan. The methodology used includes the following: visual observation and microscopy, granulometric analysis, classic wet chemical analysis, XRD, DTA and hydro tests, biological investigation. The results of scientific investigations showed, that water migration is the most aggressive agent caring out transportation of soluble salt solution and causing weathering processes of stone materials. Chemical and physical analyses of degraded dolomite, bricks and lime mortars and renders contain high concentrations of corrosion products: Na 2 CO 3 2-10%, K 2 CO 3 4,7-7,6%. By X-ray phase analyses Na 2 CO 3 x 10 H 2 O, Na 2 CO 3 · H 2 O, K 2 CO 3 and Na 2 SO 4 were found. (Authors)

  3. Sea-water intake tower works for Hamaoka Nuclear Power Station No. 2 Plant

    Energy Technology Data Exchange (ETDEWEB)

    Sataki, N; Sugaya, Y; Sugimoto, T [Chubu Electric Power Co. Inc., Nagoya (Japan)

    1976-01-01

    It was determined to adopt tunnel system based on the conclusion of negotiation with local people, specifically fishermen, for the sea water intake arrangement in Hamaoka Nuclear Power Station. The main factors for determining the location of the intake tower included marine conditions such as waves and littoral sand drift, and the sea-bottom topographic features and geology of tunnel route, for which field examination, hydraulic experiments and the research and investigation on the method of construction were carried out. These results in the No.2 tower installation at the point 65 m to the east of the No.1 tower. The construction of the tower is described on the manufacture and conveyance of steel caisson, land works at Omaezaki and temporary assembly works on the sea. Then the details of tower installation and the works on site are reported. Fortunately the difficult sea works have been satisfactorily completed earlier than planned, without any accident. The construction facilities utilizing a pilot tunnel seem to have made the better achievement than expected. In spite of the results, the lifting up, off-shore conveyance, and installation of the intake tower caisson, a superheavy structure of weighting up to total 2900 ton, were critical works.

  4. Sea-water intake tower works for Hamaoka Nuclear Power Station No. 2 Plant

    International Nuclear Information System (INIS)

    Satake, Norimoto; Sugaya, Yoshinobu; Sugimoto, Tadao

    1976-01-01

    It was determined to adopt tunnel system based on the conclusion of negotiation with local people, specifically fishermen, for the sea water intake arrangement in Hamaoka Nuclear Power Station. The main factors for determining the location of the intake tower included marine conditions such as waves and littoral sand drift, and the sea-bottom topographic features and geology of tunnel route, for which field examination, hydraulic experiments and the research and investigation on the method of construction were carried out. These results in the No.2 tower installation at the point 65 m to the east of the No.1 tower. The construction of the tower is described on the manufacture and conveyance of steel caisson, land works at Omaezaki and temporary assembly works on the sea. Then the details of tower installation and the works on site are reported. Fortunately the difficult sea works have been satisfactorily completed earlier than planned, without any accident. The construction facilities utilizing a pilot tunnel seem to have made the better achievement than expected. In spite of the results, the lifting up, off-shore conveyance, and installation of the intake tower caisson, a superheavy structure of weighting up to total 2900 ton, were critical works. (Wakatsuki, Y.)

  5. Aerodynamical errors on tower mounted wind speed measurements due to the presence of the tower

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, H. [Uppsala Univ. (Sweden). Dept. of Meteorology; Dahlberg, J.Aa. [Aeronautical Research Inst. of Sweden, Bromma (Sweden)

    1996-12-01

    Field measurements of wind speed from two lattice towers showed large differences for wind directions where the anemometers of both towers should be unaffected by any upstream obstacle. The wind speed was measured by cup anemometers mounted on booms along the side of the tower. A simple wind tunnel test indicates that the boom, for the studied conditions, could cause minor flow disturbances. A theoretical study, by means of simple 2D flow modelling of the flow around the mast, demonstrates that the tower itself could cause large wind flow disturbances. A theoretical study, based on simple treatment of the physics of motion of a cup anemometer, demonstrates that a cup anemometer is sensitive to velocity gradients across the cups and responds clearly to velocity gradients in the vicinity of the tower. Comparison of the results from the theoretical study and field tests show promising agreement. 2 refs, 8 figs

  6. Development of high performance and very low radioactivity scintillation counters for the SuperNEMO calorimeter

    International Nuclear Information System (INIS)

    Chauveau, E.

    2010-11-01

    SuperNEMO is a next generation double beta decay experiment which will extend the successful 'tracko-calo' technique employed in NEMO 3. The main characteristic of this type of detector is to identify not only double beta decays, but also to measure its own background components. The project aims to reach a sensitivity up to 10 26 years on the half-life of 82 Se. One of the main challenge of the Research and Development is to achieve an unprecedented energy resolution for the electron calorimeter, better than 8 % FWHM at 1 MeV. This thesis contributes to improve scintillators and photomultipliers performances and reduce their radioactivity, including in particular the development of a new photomultiplier in collaboration with Photonis. (author)

  7. Mathematical Model of Two Phase Flow in Natural Draft Wet-Cooling Tower Including Flue Gas Injection

    Directory of Open Access Journals (Sweden)

    Hyhlík Tomáš

    2016-01-01

    Full Text Available The previously developed model of natural draft wet-cooling tower flow, heat and mass transfer is extended to be able to take into account the flow of supersaturated moist air. The two phase flow model is based on void fraction of gas phase which is included in the governing equations. Homogeneous equilibrium model, where the two phases are well mixed and have the same velocity, is used. The effect of flue gas injection is included into the developed mathematical model by using source terms in governing equations and by using momentum flux coefficient and kinetic energy flux coefficient. Heat and mass transfer in the fill zone is described by the system of ordinary differential equations, where the mass transfer is represented by measured fill Merkel number and heat transfer is calculated using prescribed Lewis factor.

  8. Development and Pre-Operational Validation of NEMO Based Eddy Ressolving Regional Configuration for Gulf of Finland

    Science.gov (United States)

    Sofina, Ekaterina; Vankevich, Roman; Tatiana, Eremina

    2014-05-01

    At the present day RSHU the Operational Oceanographic System for the Gulf of Finland (GULFOOS) is in a trial operation. For the future development of the operational system, the quality of which also strongly depends on the hydrothermodynamic model spatial resolution. The new model configuration has been implemented, based on the international project NEMO (Nucleus for European Modelling of the Ocean). Based on NEMO toolbox a new eddy permitting z-coordinated configuration realized with horizontal resolution 30x15'' (~500 m) and 1 m vertical step. Chosen horizontal resolution enough to resolve typical submesoscale eddies in this basin where the internal Rossby radius is usually 2-4 km [1]. Verification performed with use all available measurements including vessel, ferry boxes, autonomous profilers, satellite SST. It was shown that submesoscale eddies and filaments generated by baroclinic instability of fronts in upper layers of the Gulf can change vertical stratification and deepening of the mixed layer. Increase in the model resolution leads to a clear improvement of the representation of the key hydro-physical fields: filaments propagation, local eddies. Obtained results confirm that model adequately reproduce general circulation and seasonal evolution of vertical water structure. It is shown that NEMO model initially designed for a global ocean can be used in regional operational application in case of highly stratified shallow basin with complex bathymetry. Computation efficiency of the system including 3DVar assimilation was enough for 24x7 operational task on 12 nodes of Intel based cluster. Proposed regional modeling system has potential to give information on non-observed physical quantities and to provide links between observations by identifying small-scale patterns and processes. References 1. Alenius P., Nekrasov A., Myrberg, K. The baroclinic Rossby-radius in the Gulf of Finland. Continental Shelf Research, 2003, 23, 563-573.

  9. Influence of detergents on water drift in cooling towers

    Science.gov (United States)

    Vitkovicova, Rut

    An influence of detergents on the water drift from the cooling tower was experimentally investigated. For this experimental measurements was used a model cooling tower, especially an experimental aerodynamic line, which is specially designed for the measurement and monitoring of processes taking place around the eliminators of the liquid phase. The effect of different concentrations of detergent in the cooling water on the drift of water droplets from a commonly used type eliminator was observed with visualization methods.

  10. Measurement of the 2νββ decay of 100Mo to the excited 01+ state in the NEMO3 experiment

    International Nuclear Information System (INIS)

    Vala, L.

    2003-09-01

    The NEMO3 detector was designed for the study of double beta decay and in particular to search for the neutrinoless double beta decay process (0νββ). The intended sensitivity in terms of a half-life limit for the 0νββ decay is of the order of 10 25 y which corresponds to an effective neutrino mass m ν on the level of (0.3 - 0.1) eV. The 0νββ process is today the most promising test of the Majorana nature of the neutrino. The detector was constructed in the Modane Underground Laboratory (LSM) in France by an international collaboration including France, Russia, the Czech Republic, the USA, the UK, Finland, and Japan. The experiment has been taking data since May 2002. The quantity of 100 Mo in the detector (7 kg) allows an efficient measurement of the two-neutrino double beta decay (2νββ) of 100 Mo to the excited 0 1 + state (eeNγ channel). Monte-Carlo simulations of the effect and of all the relative sources of background have been produced in order to define a set of appropriate selection criteria. Both Monte-Carlo simulations and special runs with sources of 208 Tl and 214 Bi showed that the only significant background in the eeNγ channel comes from radon that penetrated inside the wire chamber of NEMO3. The experimental data acquired from May 2002 to May 2003 have been analysed in order to determine the signal from the 2νββ decay of 100 Mo to the excited 0 1 + state and the corresponding background level. The physical result, which was obtained at the level of four standard deviations, is given in the form of an interval of half-life values at 95% confidence level: [5.84*10 20 , 2.26*10 21 ] y for method A and [5.83*10 20 , 1.71*10 21 ] y for method B. (author)

  11. Influence of detergents on water drift in cooling towers

    Directory of Open Access Journals (Sweden)

    Vitkovicova Rut

    2017-01-01

    Full Text Available An influence of detergents on the water drift from the cooling tower was experimentally investigated. For this experimental measurements was used a model cooling tower, especially an experimental aerodynamic line, which is specially designed for the measurement and monitoring of processes taking place around the eliminators of the liquid phase. The effect of different concentrations of detergent in the cooling water on the drift of water droplets from a commonly used type eliminator was observed with visualization methods.

  12. Search for evidence of lepton number violation by neutrinoless double beta decay process from 82Se and 150Nd in NEMO-3 experiment: Bi-Po decay study from thoron chain

    International Nuclear Information System (INIS)

    Lemiere, Y.

    2008-09-01

    The NEMO-3 experiment searches for a neutrinoless double beta decay signal (ββ0ν) with an expected sensitivity in terms of the half-life limit of the order of 10 24 years. The discovery of this signal, forbidden in the Standard Model, would imply the violation of leptonic number conservation and would allow to determine the nature of this particle (Dirac or Majorana) and measure the neutrino mass scale. The goal of this work is to study high energy events from 82 Se and 150 Nd ββ decay used in NEMO-3 detector. The first part of this work consists in the elaboration of a background model using NEMO-3 data. In the second part, the ββ2ν half-life and a lower limit of the ββ0ν half-life are computed using massive Majorana neutrino exchange hypothesis, we have got: T(0ν) > 1.44*10 22 years for 150 Nd and T(0ν) > 1.82*10 23 years for 82 Se. The upper limits for the effective mass of the Majorana neutrinos are also computed, we obtain: m ββ 150 Nd and m ββ 82 Se. In the last part, the measurement of some specific thallium contamination is performed thanks to the NEMO-3 capability to detect the 212 Bi-Po decay. The measured value of the surface contamination of the calorimeter is about (150 ± 30) μBq/m 3 . So the surface contamination is too low to intervene in the data analysis of NEMO-3 but appears important for next generation scintillators

  13. Probing new physics models of neutrinoless double beta decay with SuperNEMO

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, R. [CNRS/IN2P3, IPHC, Universite de Strasbourg, Strasbourg (France); Augier, C.; Bongrand, M.; Garrido, X.; Jullian, S.; Sarazin, X.; Simard, L. [CNRS/IN2P3, LAL, Universite Paris-Sud 11, Orsay (France); Baker, J.; Caffrey, A.J.; Horkley, J.J.; Riddle, C.L. [INL, Idaho Falls, ID (United States); Barabash, A.S.; Konovalov, S.I.; Umatov, V.I.; Vanyushin, I.A. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation); Basharina-Freshville, A.; Evans, J.J.; Flack, R.; Holin, A.; Kauer, M.; Richards, B.; Saakyan, R.; Thomas, J.; Vasiliev, V.; Waters, D. [University College London, London (United Kingdom); Brudanin, V.; Egorov, V.; Kochetov, O.; Nemchenok, I.; Timkin, V.; Tretyak, V.; Vasiliev, R. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Cebrian, S.; Dafni, T.; Irastorza, I.G.; Gomez, H.; Iguaz, F.J.; Luzon, G.; Rodriguez, A. [University of Zaragoza, Zaragoza (Spain); Chapon, A.; Durand, D.; Guillon, B.; Mauger, F. [Universite de Caen, LPC Caen, ENSICAEN, Caen (France); Chauveau, E.; Hubert, P.; Hugon, C.; Lutter, G.; Marquet, C.; Nachab, A.; Nguyen, C.H.; Perrot, F.; Piquemal, F.; Ricol, J.S. [UMR 5797, Universite de Bordeaux, Centre d' Etudes Nucleaires de Bordeaux Gradignan, Gradignan (France); UMR 5797, CNRS/IN2P3, Centre d' Etudes Nucleaires de Bordeaux Gradignan, Gradignan (France); Deppisch, F.F.; Jackson, C.M.; Nasteva, I.; Soeldner-Rembold, S. [Univ. of Manchester (United Kingdom); Diaz, J.; Monrabal, F.; Serra, L.; Yahlali, N. [CSIC - Univ. de Valencia, IFIC (Spain); Fushima, K.I. [Tokushima Univ., Tokushima (Japan); Holy, K.; Povinec, P.P.; Simkovic, F. [Comenius Univ., FMFI, Bratislava (Slovakia); Ishihara, N. [KEK, Tsukuba, Ibaraki (Japan); Kovalenko, V. [CNRS/IN2P3, IPHC, Univ. de Strasbourg (France); Joint Inst. for Nuclear Research, Dubna (Russian Federation); Lamhamdi, T. [USMBA, Fes (Morocco); Lang, K.; Pahlka, R.B. [Univ. of Texas, Austin, TX (United States)] (and others)

    2010-12-15

    The possibility to probe new physics scenarios of light Majorana neutrino exchange and right-handed currents at the planned next generation neutrinoless double {beta} decay experiment SuperNEMO is discussed. Its ability to study different isotopes and track the outgoing electrons provides the means to discriminate different underlying mechanisms for the neutrinoless double {beta} decay by measuring the decay half-life and the electron angular and energy distributions. (orig.)

  14. NEMO on the shelf: assessment of the Iberia–Biscay–Ireland configuration

    Directory of Open Access Journals (Sweden)

    C. Maraldi

    2013-08-01

    Full Text Available This work describes the design and validation of a high-resolution (1/36° ocean forecasting model over the "Iberian–Biscay–Irish" (IBI area. The system has been set-up using the NEMO model (Nucleus for European Modelling of the Ocean. New developments have been incorporated in NEMO to make it suitable to open- as well as coastal-ocean modelling. In this paper, we pursue three main objectives: (1 to give an overview of the model configuration used for the simulations; (2 to give a broad-brush account of one particular aspect of this work, namely consistency verification; this type of validation is conducted upstream of the implementation of the system before it is used for production and routinely validated; it is meant to guide model development in identifying gross deficiencies in the modelling of several key physical processes; and (3 to show that such a regional modelling system has potential as a complement to patchy observations (an integrated approach to give information on non-observed physical quantities and to provide links between observations by identifying broader-scale patterns and processes. We concentrate on the year 2008. We first provide domain-wide consistency verification results in terms of barotropic tides, transports, sea surface temperature and stratification. We then focus on two dynamical subregions: the Celtic shelves and the Bay of Biscay slope and deep regions. The model–data consistency is checked for variables and processes such as tidal currents, tidal fronts, internal tides and residual elevation. We also examine the representation in the model of a seasonal pattern of the Bay of Biscay circulation: the warm extension of the Iberian Poleward Current along the northern Spanish coast (Navidad event in the winter of 2007–2008.

  15. Wind-induced response analysis of a wind turbine tower including the blade-tower coupling effect

    Institute of Scientific and Technical Information of China (English)

    Xiao-bo CHEN; Jing LI; Jian-yun CHEN

    2009-01-01

    To analyze wind-induced response characteristics of a wind turbine tower more accurately, the blade-tower coupling effect was investigated. The mean wind velocity of the rotating blades and tower was simulated according to wind shear effects,and the fluctuating wind velocity time series of the wind turbine were simulated by a harmony superposition method. A dynamic finite element method (FEM) was used to calculate the wind-induced response of the blades and tower. Wind-induced responses of the tower were calculated in two cases (one included the blade-tower coupling effect, and the other only added the mass of blades and the hub at the top of the tower), and then the maximal displacements at the top of the tower of the tow cases were compared with each other. As a result of the influence of the blade-tower coupling effect and the total base shear of the blades, the maximal displacement of the first case increased nearly by 300% compared to the second case. To obtain more precise analysis, the blade-tower coupling effect and the total base shear of the blades should be considered simultaneously in the design of wind turbine towers.

  16. Tower counts

    Science.gov (United States)

    Woody, Carol Ann; Johnson, D.H.; Shrier, Brianna M.; O'Neal, Jennifer S.; Knutzen, John A.; Augerot, Xanthippe; O'Neal, Thomas A.; Pearsons, Todd N.

    2007-01-01

    Counting towers provide an accurate, low-cost, low-maintenance, low-technology, and easily mobilized escapement estimation program compared to other methods (e.g., weirs, hydroacoustics, mark-recapture, and aerial surveys) (Thompson 1962; Siebel 1967; Cousens et al. 1982; Symons and Waldichuk 1984; Anderson 2000; Alaska Department of Fish and Game 2003). Counting tower data has been found to be consistent with that of digital video counts (Edwards 2005). Counting towers do not interfere with natural fish migration patterns, nor are fish handled or stressed; however, their use is generally limited to clear rivers that meet specific site selection criteria. The data provided by counting tower sampling allow fishery managers to determine reproductive population size, estimate total return (escapement + catch) and its uncertainty, evaluate population productivity and trends, set harvest rates, determine spawning escapement goals, and forecast future returns (Alaska Department of Fish and Game 1974-2000 and 1975-2004). The number of spawning fish is determined by subtracting subsistence, sport-caught fish, and prespawn mortality from the total estimated escapement. The methods outlined in this protocol for tower counts can be used to provide reasonable estimates ( plus or minus 6%-10%) of reproductive salmon population size and run timing in clear rivers. 

  17. Water tower

    CERN Multimedia

    CERN PhotoLab

    1970-01-01

    The water tower, being built on the highest point of the site, 460.5 m above the sea level. The tank will hold 750 m3 of water, and the tower will be topped by a knob which can serve as a geological survey reference mark.

  18. Hexcrete Tower for Harvesting Wind Energy at Taller Hub Heights - Budget Period 2

    Energy Technology Data Exchange (ETDEWEB)

    Sritharan, Sri [Iowa State Univ., Ames, IA (United States)

    2017-05-01

    Interest in designing taller towers for wind energy production in the United States (U.S.) has been steadily growing. In May 2015, it was revealed that taller towers will make wind energy production a reality in all 50 states, including some states that have nearly zero renewables in their energy portfolio. Facilitating wind energy production feasibility in all 50 states will no doubt contribute to increasing the electricity produced by wind from 4.5% in 2013 to a targeted scenario of 35% by 2050 in the Wind Vision report. This project focuses on the Hexcrete tower concept developed for tall towers using High Strength Concrete (HSC) and/or Ultra-High Performance Concrete (UHPC). Among other benefits, the Hexcrete concept overcomes transportation and logistical challenges, thus facilitating construction of towers with hub heights of 100-m (328-ft) and higher. The goal of this project is to facilitate widespread deployment of Hexcrete towers for harvesting wind energy at 120 to 140-m (394 to 459-ft) hub heights and reduce the Levelized Cost of Energy (LCOE) of wind energy production in the U.S. The technical scope of the project includes detailed design and optimization of at least three wind turbine towers using the Hexcrete concept together with experimental validation and LCOE analyses and development of a commercialization plan.

  19. Oceanographic conditions in the NEMO region during the KM3NeT project (April 2006-May 2009)

    International Nuclear Information System (INIS)

    Sparnocchia, Stefania; Pietro Gasparini, Gian; Schroeder, Katrin; Borghini, Mireno

    2011-01-01

    An intense observational activity was conducted in the NEMO region, western Ionian Sea, 40 nm south-east of Capo Passero (Sicily), in the framework of the KM3NeT project. Several oceanographic cruises were performed from 2006 to 2009 and current measurements carried out. The new data describe the present status of the deep layer and its evolution after the occurrence of a notable change that affected the Eastern Mediterranean water masses and circulation during the 1990's. In particular, they evidence the presence of a newly formed water mass in the abyssal layer of the Ionian Sea, coming likely from the Adriatic. Deep currents in the region are quite energetic, as already known, and highly variable both spatially and in strength. They are organized in a cyclonic circuit, with a prevalent north-west direction corresponding to the NEMO site.

  20. The effect of a tall tower on flow and dispersion through a model urban neighborhood: part 2. Pollutant dispersion.

    Science.gov (United States)

    Brixey, Laurie A; Heist, David K; Richmond-Bryant, Jennifer; Bowker, George E; Perry, Steven G; Wiener, Russell W

    2009-12-01

    This article is the second in a two-paper series presenting results from wind tunnel and computational fluid dynamics (CFD) simulations of flow and dispersion in an idealized model urban neighborhood. Pollutant dispersion results are presented and discussed for a model neighborhood that was characterized by regular city blocks of three-story row houses with a single 12-story tower located at the downwind edge of one of these blocks. The tower had three significant effects on pollutant dispersion in the surrounding street canyons: drawing the plume laterally towards the tower, greatly enhancing the vertical dispersion of the plume in the wake of the tower, and significantly decreasing the residence time of pollutants in the wake of the tower. In the wind tunnel, tracer gas released in the avenue lee of the tower, but several blocks away laterally, was pulled towards the tower and lifted in the wake of the tower. The same lateral movement of the pollutant was seen in the next avenue, which was approximately 2.5 tower heights downwind of the tower. The tower also served to ventilate the street canyon directly in its wake more rapidly than the surrounding areas. This was evidenced by CFD simulations of concentration decay where the residence time of pollutants lee of the 12-story tower was found to be less than half the residence time behind a neighboring three-story building. This same phenomenon of rapid vertical dispersion lee of a tower among an array of smaller buildings was also demonstrated in a separate set of wind tunnel experiments using an array of cubical blocks. A similar decrease in the residence time was observed when the height of one block was increased.

  1. The influence of liquid-gas velocity ratio on the noise of the cooling tower

    Science.gov (United States)

    Yang, Bin; Liu, Xuanzuo; Chen, Chi; Zhao, Zhouli; Song, Jinchun

    2018-05-01

    The noise from the cooling tower has a great influence on psychological performance of human beings. The cooling tower noise mainly consists of fan noise, falling water noise and mechanical noise. This thesis used DES turbulence model with FH-W model to simulate the flow and sound pressure field in cooling tower based on CFD software FLUENT and analyzed the influence of different kinds noise, which affected by diverse factors, on the cooling tower noise. It can be concluded that the addition of cooling water can reduce the turbulence and vortex noise of the rotor fluid field in the cooling tower at some extent, but increase the impact noise of the liquid-gas two phase. In general, the cooling tower noise decreases with the velocity ratio of liquid to gas increasing, and reaches the lowest when the velocity ratio of liquid to gas is close to l.

  2. Rapid quantification of viable Legionella in nuclear cooling tower waters using filter cultivation, fluorescent in situ hybridization and solid-phase cytometry.

    Science.gov (United States)

    Baudart, J; Guillaume, C; Mercier, A; Lebaron, P; Binet, M

    2015-05-01

    To develop a rapid and sensitive method to quantify viable Legionella spp. in cooling tower water samples. A rapid, culture-based method capable of quantifying as few as 600 Legionella microcolonies per litre within 2 days in industrial waters was developed. The method combines a short cultivation step of microcolonies on GVPC agar plate, specific detection of Legionella cells by a fluorescent in situ hybridization (FISH) approach, and a sensitive enumeration using a solid-phase cytometer. Following optimization of the cultivation conditions, the qualitative and quantitative performance of the method was assessed and the method was applied to 262 nuclear power plant cooling water samples. The performance of this method was in accordance with the culture method (NF-T 90-431) for Legionella enumeration. The rapid detection of viable Legionella in water is a major concern to the effective monitoring of this pathogenic bacterium in the main water sources involved in the transmission of legionellosis infection (Legionnaires' disease). The new method proposed here appears to be a robust, efficient and innovative means for rapidly quantifying cultivable Legionella in cooling tower water samples within 48 h. © 2015 The Society for Applied Microbiology.

  3. Origin and prevention of infection with Legionella pneumophila through cooling towers and evaporative cooling towers

    International Nuclear Information System (INIS)

    Schulze-Roebbecke, R.

    1994-01-01

    Evaporative cooling towers and industrial ventilator cooling towers have repeatedly been described as the origin of Legionnaires' disease. This article describes the design and function of cooling towers and evaporative cooling towers, sums up knowledge on the colonization of such systems with Legionella pneumophila, and describes conditions permitting the transmission of Legionella. Furthermore, design, maintenance, cleaning and disinfection measures are indicated which are believed to reduce the risk of infection through industrial and evaporative cooling towers. (orig.) [de

  4. Statistics Analysis Measures Painting of Cooling Tower

    Directory of Open Access Journals (Sweden)

    A. Zacharopoulou

    2013-01-01

    Full Text Available This study refers to the cooling tower of Megalopolis (construction 1975 and protection from corrosive environment. The maintenance of the cooling tower took place in 2008. The cooling tower was badly damaged from corrosion of reinforcement. The parabolic cooling towers (factory of electrical power are a typical example of construction, which has a special aggressive environment. The protection of cooling towers is usually achieved through organic coatings. Because of the different environmental impacts on the internal and external side of the cooling tower, a different system of paint application is required. The present study refers to the damages caused by corrosion process. The corrosive environments, the application of this painting, the quality control process, the measures and statistics analysis, and the results were discussed in this study. In the process of quality control the following measurements were taken into consideration: (1 examination of the adhesion with the cross-cut test, (2 examination of the film thickness, and (3 controlling of the pull-off resistance for concrete substrates and paintings. Finally, this study refers to the correlations of measurements, analysis of failures in relation to the quality of repair, and rehabilitation of the cooling tower. Also this study made a first attempt to apply the specific corrosion inhibitors in such a large structure.

  5. Airspace Technology Demonstration 2 (ATD-2) Phase 1 Concept of Use (ConUse)

    Science.gov (United States)

    Jung, Yoon; Engelland, Shawn; Capps, Richard; Coppenbarger, Rich; Hooey, Becky; Sharma, Shivanjli; Stevens, Lindsay; Verma, Savita; Lohr, Gary; Chevalley, Eric; hide

    2018-01-01

    This document presents an operational Concept of Use (ConUse) for the Phase 1 Baseline Integrated Arrival, Departure, and Surface (IADS) prototype system of NASA's Airspace Technology Demonstration 2 (ATD-2) sub-project, which began demonstration in 2017 at Charlotte Douglas International Airport (CLT). NASA is developing the IADS system under the ATD-2 sub-project in coordination with the Federal Aviation Administration (FAA) and aviation industry partners. The primary goal of ATD-2 sub-project is to improve the predictability and the operational efficiency of the air traffic system in metroplex environments, through the enhancement, development, and integration of the nation's most advanced and sophisticated arrival, departure, and surface prediction, scheduling, and management systems. The ATD-2 effort is a five-year research activity through 2020. The initial phase of the ATD-2 sub-project, which is the focus of this document, will demonstrate the Phase 1 Baseline IADS capability at CLT in 2017. The Phase 1 Baseline IADS capabilities of the ATD-2 sub-project consists of: (a) Strategic and tactical surface scheduling to improve efficiency and predictability of airport surface operations, (b) Tactical departure scheduling to enhance merging of departures into overhead traffic streams via accurate predictions of takeoff times and automated coordination between the Airport Traffic Control Tower (ATCT, or Tower) and the Air Route Traffic Control Center (ARTCC, or Center), (c) Improvements in departure surface demand predictions in Time Based Flow Management (TBFM), (d) A prototype Electronic Flight Data (EFD) system provided by the FAA via the Terminal Flight Data Manager (TFDM) early implementation effort, and (e) Improved situational awareness and demand predictions through integration with the Traffic Flow Management System (TFMS), TBFM, and TFDM (3Ts) for electronic data integration and exchange, and an on-screen dashboard displaying pertinent analytics in real

  6. Composite wind turbine towers

    Energy Technology Data Exchange (ETDEWEB)

    Polyzois, D. [Manitoba Univ., Winnipeg, MB (Canada). Dept. of Civil Engineering

    2008-07-01

    This paper discussed experiments conducted to optimized the advanced composite materials such as fiberglass reinforced plastics (FRP) used to fabricate wind turbine towers. FRP materials are used in tubular steel, lattice, guyed, and reinforced concrete towers. The towers and turbine blades are transported in segments and assembled on-site, sometimes in offshore or remote locations.The FRP composites are used to build towers with a high strength-to-weight ratio as well as to provide resistance to chemical attacks and corrosion. Use of the materials has resulted in towers that do not require heavy installation equipment. Experimental programs were conducted to verify the structural behaviour of the tower structure's individual-scaled cells as well as to evaluate the performance of multi-cell assemblies. Joint assembly designs were optimized, and a filament winding machine was used to conduct the experimental study and to test individual cells. Failure mode analyses were conducted to determine local buckling and shear rupture. Tension, compression, and shear properties of the FRP materials were tested experimentally, and data from the test were then used to develop finite element models of the composite towers as well as to obtain load deflection curves and tip oscillation data. A case study of a 750 kW wind turbine in Churchill, Manitoba was used to test the design. tabs., figs.

  7. Improve crossflow cooling tower operation

    International Nuclear Information System (INIS)

    Burger, R.

    1989-01-01

    This paper reports how various crossflow cooling tower elements can be upgraded. A typical retrofit example is presented. In the past decade, cooling tower technology has progressed. If a cooling tower is over ten years old, chances are the heat transfer media and mechanical equipment were designed over 30 to 40 years ago. When a chemical plant expansion is projected or a facility desires to upgrade its equipment for greater output and energy efficiency, the cooling tower is usually neglected until someone discovers that the limiting factor of production is the quality of cold water returning from the cooling tower

  8. Good Towers of Function Fields

    DEFF Research Database (Denmark)

    Bassa, Alp; Beelen, Peter; Nguyen, Nhut

    2014-01-01

    In this paper, we will give an overview of known and new techniques on how one can obtain explicit equations for candidates of good towers of function fields. The techniques are founded in modular theory (both the classical modular theory and the Drinfeld modular theory). In the classical modular...... setup, optimal towers can be obtained, while in the Drinfeld modular setup, good towers over any non-prime field may be found. We illustrate the theory with several examples, thus explaining some known towers as well as giving new examples of good explicitly defined towers of function fields....

  9. Wind tower service lift

    Science.gov (United States)

    Oliphant, David; Quilter, Jared; Andersen, Todd; Conroy, Thomas

    2011-09-13

    An apparatus used for maintaining a wind tower structure wherein the wind tower structure may have a plurality of legs and may be configured to support a wind turbine above the ground in a better position to interface with winds. The lift structure may be configured for carrying objects and have a guide system and drive system for mechanically communicating with a primary cable, rail or other first elongate member attached to the wind tower structure. The drive system and guide system may transmit forces that move the lift relative to the cable and thereby relative to the wind tower structure. A control interface may be included for controlling the amount and direction of the power into the guide system and drive system thereby causing the guide system and drive system to move the lift relative to said first elongate member such that said lift moves relative to said wind tower structure.

  10. Measurement of the two neutrino double beta decay half-life of Zr-96 with the NEMO-3 detector

    Energy Technology Data Exchange (ETDEWEB)

    Argyriades, J. [LAL, Universite Paris-Sud 11, CNRS/IN2P3, F-91405 Orsay (France); Arnold, R. [IPHC, Universite de Strasbourg, CNRS/IN2P3, F-67037 Strasbourg (France); Augier, C. [LAL, Universite Paris-Sud 11, CNRS/IN2P3, F-91405 Orsay (France); Baker, J. [INL, Idaho National Laboratory, 83415 Idaho Falls (United States); Barabash, A.S. [ITEP, Institute of Theoretical and Experimental Physics, 117259 Moscow (Russian Federation); Basharina-Freshville, A. [University College London, WC1E 6BT London (United Kingdom); Bongrand, M. [LAL, Universite Paris-Sud 11, CNRS/IN2P3, F-91405 Orsay (France); Broudin-Bay, G. [Universite Bordeaux, CENBG, UMR 5797, F-33175 Gradignan (France); CNRS/IN2P3, Centre d' Etudes Nucleaires de Bordeaux Gradignan, UMR5797, F-33175 Gradignan (France); Brudanin, V. [JINR, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Caffrey, A.J. [INL, Idaho National Laboratory, 83415 Idaho Falls (United States); Chapon, A. [LPC, ENSICAEN, Universite de Caen, CNRS/IN2P3, F-14032 Caen (France); Chauveau, E. [Universite Bordeaux, CENBG, UMR 5797, F-33175 Gradignan (France); CNRS/IN2P3, Centre d' Etudes Nucleaires de Bordeaux Gradignan, UMR5797, F-33175 Gradignan (France); Daraktchieva, Z. [University College London, WC1E 6BT London (United Kingdom); Durand, D. [LPC, ENSICAEN, Universite de Caen, CNRS/IN2P3, F-14032 Caen (France); Egorov, V. [JINR, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Fatemi-Ghomi, N. [University of Manchester, M13 9PL Manchester (United Kingdom); Flack, R. [University College London, WC1E 6BT London (United Kingdom); Guillon, B. [LPC, ENSICAEN, Universite de Caen, CNRS/IN2P3, F-14032 Caen (France); Hubert, Ph. [Universite Bordeaux, CENBG, UMR 5797, F-33175 Gradignan (France); CNRS/IN2P3, Centre d' Etudes Nucleaires de Bordeaux Gradignan, UMR5797, F-33175 Gradignan (France); Jullian, S. [LAL, Universite Paris-Sud 11, CNRS/IN2P3, F-91405 Orsay (France)

    2010-12-08

    Using 9.4 g of {sup 96}Zr isotope and 1221 days of data from the NEMO-3 detector corresponding to 0.031 kg y, the obtained 2{nu}{beta}{beta} decay half-life measurement is T{sub 1/2}{sup 2{nu}=}[2.35{+-}0.14(stat){+-}0.16(syst)]x10{sup 19} yr. Different characteristics of the final state electrons have been studied, such as the energy sum, individual electron energy, and angular distribution. The 2{nu} nuclear matrix element is extracted using the measured 2{nu}{beta}{beta} half-life and is M{sup 2{nu}=}0.049{+-}0.002. Constraints on 0{nu}{beta}{beta} decay have also been set.

  11. You're a What?: Tower Technician

    Science.gov (United States)

    Vilorio, Dennis

    2012-01-01

    In this article, the author talks about the role and functions of a tower technician. A tower technician climbs up the face of telecommunications towers to remove, install, test, maintain, and repair a variety of equipment--from antennas to light bulbs. Tower technicians also build shelters and radiofrequency shields for electronic equipment, lay…

  12. Cooling Tower Losses in Industry

    OpenAIRE

    Barhm Mohamad

    2017-01-01

    Cooling towers are a very important part of many chemical plants. The primary task of a cooling tower is to reject heat into the atmosphere. They represent a relatively inexpensive and dependable means of removing low-grade heat from cooling water. The make-up water source is used to replenish water lost to evaporation. Hot water from heat exchangers is sent to the cooling tower. The water exits the cooling tower and is sent back to the exchangers or to other units for further cooling.

  13. The design and stability determination of wind turbine tower

    International Nuclear Information System (INIS)

    Abas Abd Wahab; Khairul Barriyah

    2001-01-01

    In wind turbine tower design, two load categories (static and wind load) were considered. The static load for this structure is the tower self-weight, which can be calculated from its density and area of the material, whereas the wind load was calculated based on CP3: Chapter V: Part 2: 1972, using the maximum wind speed of 30 m/s. The stability of this tower under the action of these two loads has been determined using RISA-3D program. The program were subjected to two joint types, i.e pinned and fixed joints. The tower using fixed joint members has established the necessary tower stability. The simulation, calculation and results are being discussed in detail in this paper. (Author)

  14. Drop Tower Physics

    Science.gov (United States)

    Dittrich, William A.

    2014-01-01

    The drop towers of yesteryear were used to make lead shot for muskets, as described in "The Physics Teacher" in April 2012. However, modern drop towers are essentially elevators designed so that the cable can "break" on demand, creating an environment with microgravity for a short period of time, currently up to nine seconds at…

  15. Hypohidrotic ectodermal dysplasia and immunodeficiency with coincident NEMO and EDA Mutations

    Directory of Open Access Journals (Sweden)

    Michael D. Keller

    2011-11-01

    Full Text Available Ectodermal dysplasias (ED are uncommon genetic disorders resulting in abnormalities in ectodermally-derived structures. Though many ED-associated genes have been described, the NF-κB Essential Modulator (NEMO encoded by the IKBKG gene is unique in that mutations also result in severe humoral and cellular immunologic defects. We describe three unrelated kindreds with defects in both EDA and IKBKG resulting from an X-chromosome crossover. This demonstrates the importance of thorough immunologic consideration of patients with ED even when an EDA etiology is confirmed, and raises the possibility of a specific phenotype arising from coincident mutations in EDA and IKBKB.

  16. Biofouling control of industrial seawater cooling towers

    KAUST Repository

    Albloushi, Mohammed

    2017-11-01

    The use of seawater in cooling towers for industrial applications has much merit in the Gulf Cooperation Council countries due to the scarcity and availability of fresh water. Seawater make-up in cooling towers is deemed the most feasible because of its unlimited supply in coastal areas. Such latent-heat removal with seawater in cooling towers is several folds more efficient than sensible heat extraction via heat exchangers. Operational challenges such as scaling, corrosion, and biofouling are a major challenge in conventional cooling towers, where the latter is also a major issue in seawater cooling towers. Biofouling can significantly hamper the efficiency of cooling towers. The most popular methods used in cooling treatment to control biofouling are disinfection by chlorination. However, the disadvantages of chlorination are formation of harmful disinfection byproducts in the presence of high organic loading and safety concerns in the storage of chlorine gas. In this study, the research focuses on biofouling control in seawater cooling towers by investigating two different approaches. The first strategy addresses the use of alternative oxidants (i.e. ozone micro-bubbles and chlorine dioxide) in treatment of cooling towers. The second strategy investigates removing nutrients in seawater using granular activated carbon filter column and ultrafiltration to prevent the growth of microorganisms. Laboratory bench-scale tests in terms of temperature, cycle of concentration, dosage, etc. indicated that, at lower oxidant dosages (total residual oxidant (TRO) equivalent = 0.1 mg/l Cl2), chlorine dioxide had a better disinfection effect than chlorine and ozone. The performance of oxidizing biocides at pilot scale, operating at assorted conditions, showed that for the disinfectants tested, ozone could remove 95 % bioactivity of total number of bacteria and algae followed by chlorine dioxide at 85%, while conventional chlorine dosing only gave 60% reduction in bioactivities

  17. Wind turbine tower for storing hydrogen and energy

    Science.gov (United States)

    Fingersh, Lee Jay [Westminster, CO

    2008-12-30

    A wind turbine tower assembly for storing compressed gas such as hydrogen. The tower assembly includes a wind turbine having a rotor, a generator driven by the rotor, and a nacelle housing the generator. The tower assembly includes a foundation and a tubular tower with one end mounted to the foundation and another end attached to the nacelle. The tower includes an in-tower storage configured for storing a pressurized gas and defined at least in part by inner surfaces of the tower wall. In one embodiment, the tower wall is steel and has a circular cross section. The in-tower storage may be defined by first and second end caps welded to the inner surface of the tower wall or by an end cap near the top of the tower and by a sealing element attached to the tower wall adjacent the foundation, with the sealing element abutting the foundation.

  18. Structure of natural draft cooling towers, 1. Study on cooling tower shells

    Energy Technology Data Exchange (ETDEWEB)

    Ishioka, H; Sakamoto, Y; Tsurusaki, M; Koshizawa, K; Chiba, T [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    1976-09-01

    Recently in Japan, demands for cooling tower systems have been increasing remarkably with the construction of large power plants and the legislation of environmental regulations. In view of the severe natural conditions in Japan such as strong wind and seismic loadings, etc., the establishment of the optimum design and construction method is essential for the building of safe and economical towers. In order to establish a comprehensive plan of a power plant cooling system of the appropriate structural type, the authors have made researches and experiments on design conditions, static and dynamic analyses, and comparative studies of various structural types such as reinforced concrete thin-shell structures, steel framed structures and composite shell segment structures, based on the investigation results of towers in Europe and America. These results are presented in three reports, the 1st of which concerns cooling tower shells as are herein described.

  19. Fire ants perpetually rebuild sinking towers

    Science.gov (United States)

    Phonekeo, Sulisay; Mlot, Nathan; Monaenkova, Daria; Hu, David L.; Tovey, Craig

    2017-07-01

    In the aftermath of a flood, fire ants, Solenopsis invicta, cluster into temporary encampments. The encampments can contain hundreds of thousands of ants and reach over 30 ants high. How do ants build such tall structures without being crushed? In this combined experimental and theoretical study, we investigate the shape and rate of construction of ant towers around a central support. The towers are bell shaped, consistent with towers of constant strength such as the Eiffel tower, where each element bears an equal load. However, unlike the Eiffel tower, the ant tower is built through a process of trial and error, whereby failed portions avalanche until the final shape emerges. High-speed and novel X-ray videography reveal that the tower constantly sinks and is rebuilt, reminiscent of large multicellular systems such as human skin. We combine the behavioural rules that produce rafts on water with measurements of adhesion and attachment strength to model the rate of growth of the tower. The model correctly predicts that the growth rate decreases as the support diameter increases. This work may inspire the design of synthetic swarms capable of building in vertical layers.

  20. Dry cross-flow cooling tower

    Energy Technology Data Exchange (ETDEWEB)

    Fordyce, H E

    1975-01-23

    The invention deals with dry cooling towers in particular a circular cooling tower of the mechanical-draught construction whose operating characteristics should be independent of the wind direction. The recycling of the hot air should be as low as possible without necessitating high fan or natural-draught shafts, so that the costs of the tower can be brought down to a minimum.

  1. Cooling tower

    Energy Technology Data Exchange (ETDEWEB)

    Norbaeck, P; Heneby, H

    1976-01-22

    Cooling towers to be transported on road vehicles as a unit are not allowed to exceed certain dimensions. In order to improve the efficiency of such a cooling tower (of cross-flow design and box-type body) with given dimensions, it is proposed to arrange at least one of the scrubbing bodies displaceable within a module or box. Then it can be moved out of the casing into working position, thereby increasing the front surface available for the inlet of air (and with it the efficiency) by nearly a factor of two.

  2. NEMO: Extraction and normalization of organization names from PubMed affiliations.

    Science.gov (United States)

    Jonnalagadda, Siddhartha Reddy; Topham, Philip

    2010-10-04

    Today, there are more than 18 million articles related to biomedical research indexed in MEDLINE, and information derived from them could be used effectively to save the great amount of time and resources spent by government agencies in understanding the scientific landscape, including key opinion leaders and centers of excellence. Associating biomedical articles with organization names could significantly benefit the pharmaceutical marketing industry, health care funding agencies and public health officials and be useful for other scientists in normalizing author names, automatically creating citations, indexing articles and identifying potential resources or collaborators. Large amount of extracted information helps in disambiguating organization names using machine-learning algorithms. We propose NEMO, a system for extracting organization names in the affiliation and normalizing them to a canonical organization name. Our parsing process involves multi-layered rule matching with multiple dictionaries. The system achieves more than 98% f-score in extracting organization names. Our process of normalization that involves clustering based on local sequence alignment metrics and local learning based on finding connected components. A high precision was also observed in normalization. NEMO is the missing link in associating each biomedical paper and its authors to an organization name in its canonical form and the Geopolitical location of the organization. This research could potentially help in analyzing large social networks of organizations for landscaping a particular topic, improving performance of author disambiguation, adding weak links in the co-author network of authors, augmenting NLM's MARS system for correcting errors in OCR output of affiliation field, and automatically indexing the PubMed citations with the normalized organization name and country. Our system is available as a graphical user interface available for download along with this paper.

  3. Carbon Balance at Landscape Level inferred fromTower CO2 Concentration Measurements

    Science.gov (United States)

    Chen, J. M.; Chen, B.; Higuchi, K.; Chan, D.; Shashkov, A.; Lin, H.; Liu, J.

    2003-04-01

    Terrestrial carbon sinks are considerable in the global carbon budget, but the accumulation of carbon in terrestrial ecosystems is very small (~0.2% per year) relative to the total carbon stocks in forests. Currently, eddy-covariance instruments mounted on towers are the only reliable means to measure carbon balance of a land surface, albeit limited to small areas and not free of caveats. In our quest of understanding the collective performance of ecosystems under the changing climate, it is highly desirable to have the ability to acquire carbon cycle information for large areas (landscape) consisting of patches of different ecosystems. For this purpose we explored methodologies of inferring carbon cycle information from tower CO2 concentration measurements affected by large areas (100-10000 km2). An ecosystem model named Boreal Ecosystem Productivity Simulator (BEPS) is coupled with a carbon-specific Vertical Diffusion Scheme (VDS) in order to decipher temporal variations in CO2 for landscape-level photosynthesis and respiration information. The coupled BEPS-VDS is applied to a unique 9-year (1990-2000 with 1997-8 missing data) 5-minute CO2 record measured on a 40-m tower over boreal forests near Fraserdale, Ontario, Canada. Over the period, the mean diurnal amplitude of the measured CO2 at 40 m increased by 5.58 ppmv, or 28% in the growing season. The increase in nighttime ecosystem respiration, causing the increase in the daily maximum CO2 concentration, was responsible for 65% of the increase in the diurnal amplitude, i.e., 3.61 ppmv, corresponding to an increase in the mean daily air temperature by about 2.77 degC and precipitation by 5% over the same period. The rest (35%) is explained by the increase in ecosystem daytime photosynthesis, causing the decrease in the daily minimum CO2 concentration. As the nighttime stable boundary layer (SBL) (270-560 m) was much shallower than the daytime convective boundary layer (CBL) (1000-1600 m), the increase in

  4. Brayton-Cycle Baseload Power Tower CSP System

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Bruce [Wilson Solarpower Corporation, Boston, MA (United States)

    2013-12-31

    The primary objectives of Phase 2 of this Project were:1. Engineer, fabricate, and conduct preliminary testing on a low-pressure, air-heating solar receiver capable of powering a microturbine system to produce 300kWe while the sun is shining while simultaneously storing enough energy thermally to power the system for up to 13 hours thereafter. 2. Cycle-test a high-temperature super alloy, Haynes HR214, to determine its efficacy for the system’s high-temperature heat exchanger. 3. Engineer the thermal energy storage system. This Phase 2 followed Wilson’s Phase 1, which primarily was an engineering feasibility study to determine a practical and innovative approach to a full Brayton-cycle system configuration that could meet DOE’s targets. Below is a summary table of the DOE targets with Wilson’s Phase 1 Project results. The results showed that a Brayton system with an innovative (low pressure) solar receiver with ~13 hours of dry (i.e., not phase change materials or molten salts but rather firebrick, stone, or ceramics) has the potential to meet or exceed DOE targets. Such systems would consist of pre-engineered, standardized, factory-produced modules to minimize on-site costs while driving down costs through mass production. System sizes most carefully analyzed were in the range of 300 kWe to 2 MWe. Such systems would also use off-the-shelf towers, blowers, piping, microturbine packages, and heliostats. Per DOE’s instructions, LCOEs are based on the elevation and DNI levels of Daggett, CA, for a 100 MWe power plant following 2 GWe of factory production of the various system components.

  5. Induced draught circular cooling tower

    International Nuclear Information System (INIS)

    Blanquet, J.C.

    1980-01-01

    Induced draught atmospheric cooling towers are described, to wit those in which the circulation is by power fans. This technique with fans grouped together in the centre enables a single tower to be used and provides an excellent integration of the steam wreath into the atmosphere. This type of cooling tower has been chosen for fitting out two 900 MW units of the Chinon power station in France [fr

  6. Cooling towers of nuclear power plants

    International Nuclear Information System (INIS)

    Mikyska, L.

    1986-01-01

    The specifications are given of cooling towers of foreign nuclear power plants and a comparison is made with specifications of cooling towers with natural draught in Czechoslovak nuclear power plants. Shortcomings are pointed out in the design of cooling towers of Czechoslovak nuclear power plants which have been derived from conventional power plant design. The main differences are in the adjustment of the towers for winter operation and in the designed spray intensity. The comparison of selected parameters is expressed graphically. (J.B.)

  7. Coherence Effects on the Power and Tower Loads of a 7 × 2 MW Multi-Rotor Wind Turbine System

    Directory of Open Access Journals (Sweden)

    Shigeo Yoshida

    2016-09-01

    Full Text Available A multi-rotor system (MRS, in which multiple wind turbines are placed on one tower, is a promising concept for super-large wind turbines at over 10 MW due to the cost and weight advantages. The coherence effects on an MRS were investigated in this study. Although a wide range of coherences were measured so far, a decay constant of C = 12 is recommended in the IEC61400-1 standard. Dynamic simulations were performed for a 14-MW MRS, which consists of seven 2-MW turbines and includes wind models with three different coherences. Although the results show that a larger coherence increases the output power and the collective loads due to tower base fore-aft bending, it reduces the differential loads due to tower-base torque and tower-top nodding. The most significant case is the fatigue damage due to tower base fore-aft bending, which was more than doubled between the decay constants of C = 6 and C = 12. The present results indicate that the coherence should be defined carefully in the design of large-scale MRSs because its effect on them is not straightforward.

  8. Cooling tower modification for intermittent operation

    International Nuclear Information System (INIS)

    Midkiff, W.S.

    1975-03-01

    One of the cooling towers at Los Alamos Scientific Laboratory is being operated intermittently. The cooling tower has been modified to restrict air flow and to keep the tower from drying out. The modifications are relatively inexpensive, simple to operate, and have proved effective. (U.S.)

  9. The Second "Ring of Towers": Over-sampling the Mid Continent Intensive region CO2 mixing ratio?

    Science.gov (United States)

    Richardson, S.; Miles, N.; Davis, K.; Crosson, E.; Denning, S.; Zupanksi, D.; Uliasz, M.

    2007-12-01

    A central barrier preventing the scientific community from understanding the carbon balance of the continent is methodological; it is technically difficult to bridge the gap in spatial scales that exists between the detailed understanding of ecological processes that can be gathered via intensive local field study, and the overarching but mechanistically poor understanding of the global carbon cycle that is gained by analyzing the atmospheric CO2 budget. The NACP's Midcontinental Intensive (MCI) study seeks to bridge this gap by conducting a rigorous methodological test of our ability to measure the terrestrial carbon balance of the upper Midwest. A critical need in bridging this gap is increased data density. A primary goal of the project is to increase the regional atmospheric CO2 data density so that 1) atmospheric inversions can derive well-constrained regional ecosystem carbon flux estimates and 2) the trade off between data density and accuracy of the flux estimates can be determined quantitatively using field observations, thus providing guidance to future observational network designs. Our work adds a regional network of five communications-tower based atmospheric CO2 observations to the planned long-term atmospheric CO2 observing network (tall towers, flux towers and aircraft profiles) in the midcontinent intensive region. Measurements began in April-June 2007, If the measurements are shown to be spatially dense enough to over sample the CO2 mixing ratio, the experiment will provide an upper bounds on the density of measurements required to produce the most accurate flux possible with current atmospheric inversions. The five sites for "Ring 2" and deployment dates are Centerville, IA (Apr 07), Round Lake, MN (May 07), Kewanee, IL (Apr 07), Mead, NE (Apr 07), Galesville, WI (June 07). Two heights are sampled at each tower (30 m AGL and between 110 and 140 m AGL). More details are available at www.ring2.psu.edu. In addition, two systems in PSU's network of

  10. A test of Newton's Law of Gravity using the BREN Tower, Nevada

    International Nuclear Information System (INIS)

    Kasameyer, P.; Thomas, J.; Fackler, O.; Mugge, M.; Kammeraad, J.; Millett, M.; Harris, B.; Felske, D.

    1989-01-01

    We predicted gravity values on a tower by upward continuing an extensive set of surface data in order to test the 1/r 2 dependence of Newton's Law of Universal Gravitation. We measured gravity at 12 heights up to 454 m on a tower at the Nevada Test Site, and at 91 locations on the surface of the earth within 2.5 kilometers of the tower. These data have been combined with 60,000 surface gravity measurements within 300 kilometers of the tower and have been used to predict the gravitational field on the tower via a solution of Laplace's equation. A discrepancy between the observed gravity values and the prediction could suggest a breakdown of Newtonian Gravity, but we observe none. Our preliminary results are consistent with the Newtonian hypothesis to within 93 +- 95 μgals at the top of the tower, a result which conflicts with the previously reported 500 μgal non-Newtonian signal seen at 562 meters above the earth. 24 refs., 2 figs

  11. NEMO binds ubiquitinated TANK-binding kinase 1 (TBK1 to regulate innate immune responses to RNA viruses.

    Directory of Open Access Journals (Sweden)

    Lingyan Wang

    Full Text Available RIG-I-like receptors (RLR are intracellular sensors utilized by nearly all cell types for recognition of viral RNA, initiation of antiviral defense, and induction of type I interferons (IFN. TBK1 is a critical kinase implicated in RLR-dependent IFN transcription. Posttranslational modification of TBK1 by K63-linked ubiquitin is required for RLR driven signaling. However, the TBK1 ubiquitin acceptor sites and the function of ubiquitinated TBK1 in the signaling cascade are unknown. We now show that TBK1 is ubiquitinated on residues K69, K154, and K372 in response to infection with RNA virus. The K69 and K154 residues are critical for innate antiviral responses and IFN production. Ubiquitinated TBK1 recruits the downstream adaptor NEMO through ubiquitin binding domains. The assembly of the NEMO/TBK1 complex on the mitochondrial protein MAVS leads to activation of TBK1 kinase activity and phosphorylation of the transcription factor, interferon response factor 3. The combined results refine current views of RLR signaling, define the role of TBK1 polyubiquitination, and detail the mechanisms involved in signalosome assembly.

  12. Analytical Assessment of Environmental Impact for APR1400DC UHS Cooling Tower

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jaiho [KHNP-Central Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    Hot process water is pumped from the plant process to the cooling towers. Heat is rejected through evaporation of the process water, interacting with ambient air blown upward by fans.. Plumes generated from exit ports of the cooling tower may have adverse effects on the environment, such as deposition of cooling tower drift release, fogging, icing, shadowing, and ground-level temperature and humidity increase. These kinds of environmental impact of the cooling tower are linked closely with the dispersion of the cooling tower plumes. In this respect, predicting the behavior of the plumes has become one of the most important issues in the environmental assessments of the cooling towers. The SACTI (seasonal/annual cooling tower impact) model is an analytical tool to predict the environmental effect of cooling tower, which was developed by Argonne National Laboratory and University of Illinois with support from EPRI (electric power research institute). The initial version of SACTI has been widely used to assess the environmental effect of cooling towers in many industrial fields such as steam power plants and NPPs. Guo et. al. investigated impact of heat rejection and cooling tower height on plume dispersion using the SACTI model, for the purpose of the future construction of inland NPPs. They found that increasing cooling tower height decreases the plume length and height frequencies. Their simulation results showed that the increase in heat rejection increases the plum radius frequency. The APR1400DC is an advanced light water reactor developed for the purpose of NRC-DC (design certification). The cooling towers for APR1400DC UHS consist of two linear mechanical draft cooling towers (LMDCTs). The LMDCT for APR1400DC UHS is conceptually designed because the plant site has not been decided yet. In the present study, the dependency of plume dispersion on the number of cooling towers is investigated using SACTI-2-beta, for predicting annual environmental effect of APR

  13. Loss of coolant analysis for the tower shielding reactor 2

    International Nuclear Information System (INIS)

    Radcliff, T.D.; Williams, P.T.

    1990-06-01

    The operational limits of the Tower Shielding Reactor-2 (TSR-2) have been revised to account for placing the reactor in a beam shield, which reduces convection cooling during a loss-of-coolant accident (LOCA). A detailed heat transfer analysis was performed to set operating time limits which preclude fuel damage during a LOCA. Since a LOCA is survivable, the pressure boundary need not be safety related, minimizing seismic and inspection requirements. Measurements of reactor component emittance for this analysis revealed that aluminum oxidized in water may have emittance much higher than accepted values, allowing higher operating limits than were originally expected. These limits could be increased further with analytical or hardware improvements. 5 refs., 7 figs

  14. Component for articulated offshore loading towers

    Energy Technology Data Exchange (ETDEWEB)

    Backhaus, H.

    1980-09-01

    The construction of offshore natural gas liquefaction plants must be regarded as technically feasible and the marketing prospects for LNG - a source of clean burning energy - appear excellent. Nevertheless, the optimum loading procedure for LNG tankers in the - sometimes adverse - offshore environment is still a matter under discussion by the experts - with a tendency to adopt and adapt well-proven components from the offshore crude oil sector. Here, articulated towers are in use for tankerloading and the crude oil is pumped at ambient temperature through the cardan joint of the tower itself. In the case of the cryogenic liquid LNG, this method would entail intolerable risks. Leaks and subsequent LNG spills within the tower joint will cause low temperature-embrittlement and most likely damage the cardan connection at the tower's base plate on the sea bed. The described submarine joint for ultra-cold liquids, which has the same cardanic properties as the cardan joint of the tower is completely separated from the latter. Thus a cryogenic leakage in this submarine joint will under no circumstance reach and affect the tower cardan.

  15. Radio Transmitters and Tower Locations, Layer includes all towers identified visually and include cellular and other communication towers., Published in 2008, 1:1200 (1in=100ft) scale, Noble County Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Radio Transmitters and Tower Locations dataset current as of 2008. Layer includes all towers identified visually and include cellular and other communication towers..

  16. Measurement of the 2{nu}{beta}{beta} decay of {sup 100}Mo to the excited 0{sub 1}{sup +} state in the NEMO3 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Vala, L

    2003-09-01

    The NEMO3 detector was designed for the study of double beta decay and in particular to search for the neutrinoless double beta decay process (0{nu}{beta}{beta}). The intended sensitivity in terms of a half-life limit for the 0{nu}{beta}{beta} decay is of the order of 10{sup 25} y which corresponds to an effective neutrino mass m{sub {nu}} on the level of (0.3 - 0.1) eV. The 0{nu}{beta}{beta} process is today the most promising test of the Majorana nature of the neutrino. The detector was constructed in the Modane Underground Laboratory (LSM) in France by an international collaboration including France, Russia, the Czech Republic, the USA, the UK, Finland, and Japan. The experiment has been taking data since May 2002. The quantity of {sup 100}Mo in the detector (7 kg) allows an efficient measurement of the two-neutrino double beta decay (2{nu}{beta}{beta}) of {sup 100}Mo to the excited 0{sub 1}{sup +} state (eeN{gamma} channel). Monte-Carlo simulations of the effect and of all the relative sources of background have been produced in order to define a set of appropriate selection criteria. Both Monte-Carlo simulations and special runs with sources of {sup 208}Tl and {sup 214}Bi showed that the only significant background in the eeN{gamma} channel comes from radon that penetrated inside the wire chamber of NEMO3. The experimental data acquired from May 2002 to May 2003 have been analysed in order to determine the signal from the 2{nu}{beta}{beta} decay of {sup 100}Mo to the excited 0{sub 1}{sup +} state and the corresponding background level. The physical result, which was obtained at the level of four standard deviations, is given in the form of an interval of half-life values at 95% confidence level: [5.84*10{sup 20}, 2.26*10{sup 21}] y for method A and [5.83*10{sup 20}, 1.71*10{sup 21}] y for method B. (author)

  17. Tall tower landscape scale N2O flux measurements in a Danish agricultural and urban, coastal area

    Science.gov (United States)

    Ibrom, Andreas; Lequy, Émeline; Loubet, Benjamin; Pilegaard, Kim; Ambus, Per

    2015-04-01

    Both technical and natural processes emit the greenhouse gas nitrous oxide (N2O) into the atmosphere. The abundant use of nitrogen (N) as fertiliser increases the concentration of reactive nitrogen (Nr) in the atmosphere, the hydrosphere and in the biosphere, i.e. in terrestrial and aquatic ecosystems. Surplus Nr is distributed across linkages to other spheres until most of it is emitted to the atmosphere as NO, N2O or N2. A complete estimate of the effects from human activities on N2O emissions must therefore include all emissions, the direct emissions and the indirect emissions that happen in interlinked spheres. For this it is necessary to assess the fluxes at least at the landscape scale. The episodic nature and the large spatial variability make it difficult to estimate the direct and indirect emissions in a landscape. Modelling requires not only to include the highly variable microbial processes in the ecosystems that produce N2O but as well the accurate simulation of lateral Nr fluxes and their effects on N2O fluxes in places remote from the primary Nr sources. In this context tall tower N2O flux measurements are particularly useful as they integrate over larger areas and can be run, continuously without disturbing the fluxes. On the other hand these measurements can be difficult to interpret due to difficulties to measure the small concentration fluctuations in the atmosphere at small flux rates and to accurately attribute the measured flux at the tower to the area that generates the flux, i.e. the source area. The Technical University of Denmark (DTU) has established eddy covariance N2O flux measurements on a 125 m tall tower at its Risø Campus as part of the EU research infrastructure project the 'Integrated non-CO2 Greenhouse gas Observing System' (InGOS). The eddy covariance system consisted of a N2O/CO quantum cascade laser, Los Gatos, Mountain View, CA, USA and a 3D sonic anemometer (USA-1), Metek, Elmshorn, Germany. The Risø peninsula lies at the

  18. The future cooling tower; Fremtidens koeletaarn

    Energy Technology Data Exchange (ETDEWEB)

    Ibsen, C.H. (Vestas Aircoil A/S, Lem St. (Denmark)); Schneider, P. (Teknologisk Institut, AArhus (Denmark)); Haaning, N. (Ramboell A/S, Copenhagen (Denmark)); Lund, K. (Nyrup Plast A/S, Nyrup (Denmark)); Soerensen, Ole (MultiWing A/S, Vedbaek (Denmark)); Dalsgaard, T. (Silhorko A/S, Skanderborg (Denmark)); Pedersen, Michael (Skive Kommune, Skive (Denmark))

    2011-03-15

    This project has designed and built a pilot-scale cooling tower with an output of up to 100 kW for which good correlation has been ascertained between measured and calculated values for output and pressure loss. The new cooling tower will save approximately 15% of electricity consumption compared with the widespread dry coolers. The pilot tower uses rainwater so that both water consumption and electricity consumption are saved in softening plants. On the basis of this cooling tower, models have been made and these have been implemented in PackCalc II in order to calculate electricity and other operating savings. (Energy 11)

  19. Contrastive analysis of cooling performance between a high-level water collecting cooling tower and a typical cooling tower

    Science.gov (United States)

    Wang, Miao; Wang, Jin; Wang, Jiajin; Shi, Cheng

    2018-02-01

    A three-dimensional (3D) numerical model is established and validated for cooling performance optimization between a high-level water collecting natural draft wet cooling tower (HNDWCT) and a usual natural draft wet cooling tower (UNDWCT) under the actual operation condition at Wanzhou power plant, Chongqing, China. User defined functions (UDFs) of source terms are composed and loaded into the spray, fill and rain zones. Considering the conditions of impact on three kinds of corrugated fills (Double-oblique wave, Two-way wave and S wave) and four kinds of fill height (1.25 m, 1.5 m, 1.75 m and 2 m), numerical simulation of cooling performance are analysed. The results demonstrate that the S wave has the highest cooling efficiency in three fills for both towers, indicating that fill characteristics are crucial to cooling performance. Moreover, the cooling performance of the HNDWCT is far superior to that of the UNDWCT with fill height increases of 1.75 m and above, because the air mass flow rate in the fill zone of the HNDWCT improves more than that in the UNDWCT, as a result of the rain zone resistance declining sharply for the HNDWCT. In addition, the mass and heat transfer capacity of the HNDWCT is better in the tower centre zone than in the outer zone near the tower wall under a uniform fill layout. This behaviour is inverted for the UNDWCT, perhaps because the high-level collection devices play the role of flow guiding in the inner zone. Therefore, when non-uniform fill layout optimization is applied to the HNDWCT, the inner zone increases in height from 1.75 m to 2 m, the outer zone reduces in height from 1.75 m to 1.5 m, and the outlet water temperature declines approximately 0.4 K compared to that of the uniform layout.

  20. ANALISIS KINERJA COOLING TOWER 8330 CT01 PADA WATER TREATMENT PLANT-2 PT KRAKATAU STEEL (PERSERO. TBK

    Directory of Open Access Journals (Sweden)

    Hutriadi Pratama Siallagan

    2017-11-01

    Full Text Available Pada proses produksi baja sangat erat kaitannya dengan pendinginan baik untuk proses pendinginan baja maupun pendinginan mesin-mesin produksi supaya terhindar dari over heat sehingga dapat bekerja dengan optimal. Pada PT Krakatau Steel menggunakan beberapa sistem pendingin salah satunya adalah sistem pendingin cooling tower 8330 CT 01. Sistem pendingin tersebut digunakan untuk menunjang proses produksi dan juga pendinginanan mesin produksi khusunya pada Slab Steel Plant (SSP, dengan peran yang sangat besar maka cooling tower 8330 CT 01 harus diketahui bagaimana kinerjanya. Skripsi ini membahas tentang analisis kinerja Cooling tower 8330 CT 01 dengan membandingkan data teori dengan data aktual berdasarkan perhitungan-perhitungan sehingga dapat diketahui bagaimana kinerja dari Cooling tower 8330 CT 01 tersebut. Dari hasil analisis diperoleh penurunan efisiensi sebesar 22,353%, kapasitas pendinginan 7.033,35 Kj/s, Hal tersebut diakibatkan oleh temperatur air yang masuk Cooling tower 8330 CT 01 tidak terlalu tinggi, karena SSP sedang dalam pengerjaan revitatalisi, agar lebih efektif dan efisien Cooling tower 8330 CT 01 sebaiknya lebih dimamfaatkan lagi untuk pendingin objek lainnya sehingga temperatur air yang masuk tidak terlalu rendah.

  1. Dynamic interaction effects in cooling tower groups

    International Nuclear Information System (INIS)

    Riera, J.D.

    1984-01-01

    A theoretical and experimental determination of the dynamic response of reinforced concrete cooling towers, taking into consideration group effects, are described. The results for an individual tower are thoroughly examined. A complete analysis is then performed for the critical wind orientations, for each tower in a six towers group. It's shown that ignoring group effects in the analysis may lead to a significant underestimation of the structural response. (E.G.) [pt

  2. Simultaneous effects of water spray and crosswind on performance of natural draft dry cooling tower

    Directory of Open Access Journals (Sweden)

    Ahmadikia Hossein

    2013-01-01

    Full Text Available To investigate the effect of water spray and crosswind on the effectiveness of the natural draft dry cooling tower (NDDCT, a three-dimensional model has been developed. Efficiency of NDDCT is improved by water spray system at the cooling tower entrance for high ambient temperature condition with and without crosswind. The natural and forced heat convection flow inside and around the NDDCT is simulated numerically by solving the full Navier-Stokes equations in both air and water droplet phases. Comparison of the numerical results with one-dimensional analytical model and the experimental data illustrates a well-predicted heat transfer rate in the cooling tower. Applying water spray system on the cooling tower radiators enhances the cooling tower efficiency at both no wind and windy conditions. For all values of water spraying rate, NDDCTs operate most effectively at the crosswind velocity of 3m/s and as the wind speed continues to rise to more than 3 m/s up to 12 m/s, the tower efficiency will decrease by approximately 18%, based on no-wind condition. The heat transfer rate of radiator at wind velocity 10 m/s is 11.5% lower than that of the no wind condition. This value is 7.5% for water spray rate of 50kg/s.

  3. Explicit representation and parametrised impacts of under ice shelf seas in the z∗ coordinate ocean model NEMO 3.6

    Directory of Open Access Journals (Sweden)

    P. Mathiot

    2017-07-01

    Full Text Available Ice-shelf–ocean interactions are a major source of freshwater on the Antarctic continental shelf and have a strong impact on ocean properties, ocean circulation and sea ice. However, climate models based on the ocean–sea ice model NEMO (Nucleus for European Modelling of the Ocean currently do not include these interactions in any detail. The capability of explicitly simulating the circulation beneath ice shelves is introduced in the non-linear free surface model NEMO. Its implementation into the NEMO framework and its assessment in an idealised and realistic circum-Antarctic configuration is described in this study. Compared with the current prescription of ice shelf melting (i.e. at the surface, inclusion of open sub-ice-shelf cavities leads to a decrease in sea ice thickness along the coast, a weakening of the ocean stratification on the shelf, a decrease in salinity of high-salinity shelf water on the Ross and Weddell sea shelves and an increase in the strength of the gyres that circulate within the over-deepened basins on the West Antarctic continental shelf. Mimicking the overturning circulation under the ice shelves by introducing a prescribed meltwater flux over the depth range of the ice shelf base, rather than at the surface, is also assessed. It yields similar improvements in the simulated ocean properties and circulation over the Antarctic continental shelf to those from the explicit ice shelf cavity representation. With the ice shelf cavities opened, the widely used three equation ice shelf melting formulation, which enables an interactive computation of melting, is tested. Comparison with observational estimates of ice shelf melting indicates realistic results for most ice shelves. However, melting rates for the Amery, Getz and George VI ice shelves are considerably overestimated.

  4. 78 FR 17183 - Information Collection: Grey Towers Visitor Comment Card

    Science.gov (United States)

    2013-03-20

    ... DEPARTMENT OF AGRICULTURE Forest Service Information Collection: Grey Towers Visitor Comment Card... request: (1) An extension from the Office of Management and Budget; and (2) to merge the currently approved information collection 0596- 0222, ``Grey Towers Visitor Comment Card'' with 0596-0226, ``Forest...

  5. Cooling towers principles and practice

    CERN Document Server

    Hill, G B; Osborn, Peter D

    1990-01-01

    Cooling Towers: Principles and Practice, Third Edition, aims to provide the reader with a better understanding of the theory and practice, so that installations are correctly designed and operated. As with all branches of engineering, new technology calls for a level of technical knowledge which becomes progressively higher; this new edition seeks to ensure that the principles and practice of cooling towers are set against a background of up-to-date technology. The book is organized into three sections. Section A on cooling tower practice covers topics such as the design and operation of c

  6. Proceedings: Cooling tower and advanced cooling systems conference

    International Nuclear Information System (INIS)

    1995-02-01

    This Cooling Tower and Advanced Cooling Systems Conference was held August 30 through September 1, 1994, in St. Petersburg, Florida. The conference was sponsored by the Electric Power Research Institute (EPRI) and hosted by Florida Power Corporation to bring together utility representatives, manufacturers, researchers, and consultants. Nineteen technical papers were presented in four sessions. These sessions were devoted to the following topics: cooling tower upgrades and retrofits, cooling tower performance, cooling tower fouling, and dry and hybrid systems. On the final day, panel discussions addressed current issues in cooling tower operation and maintenance as well as research and technology needs for power plant cooling. More than 100 people attended the conference. This report contains the technical papers presented at the conference. Of the 19 papers, five concern cooling tower upgrades and retrofits, five to cooling tower performance, four discuss cooling tower fouling, and five describe dry and hybrid cooling systems. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database

  7. Cancer in proximity to TV towers

    International Nuclear Information System (INIS)

    Hocking, B.; Gordon, I.; Hatfield, G.

    1996-01-01

    Standard (AS2772.1). The few actual measurements available indicate even lower levels. The analysis shows no increased risk of brain cancer. An increased risk of childhood leukaemia is indicated in the municipalities close to the TV towers. The rate ratio for incidence is 1.6 (95% Cl: 1.08-2 41) and for mortality is 2.25 (95% Cl: 1.29-3.92), mainly due to lymphatic leukaemia (1.63 for incidence, 2.84 for mortality). An association between increased childhood leukaemia and proximity to TV towers is indicated. Further studies are needed to test this association and determine any dose-response relationship before firm conclusions may be reached

  8. Evaluating the relationships between solar-induced chlorophyll fluorescence from Orbiting Carbon Observatory-2 and gross primary productivity from eddy covariance flux towers

    Science.gov (United States)

    Li, X.; Xiao, J.; He, B.

    2017-12-01

    Solar-induced chlorophyll fluorescence (SIF) opens a new perspective on the monitoring of vegetation photosynthesis from space, and has been recently used to estimate gross primary productivity (GPP). However, previous studies on SIF were mainly based on satellite observations from the Greenhouse Gases Observing Satellite (GOSAT) and Global Ozone Monitoring Experiment-2 (GOME-2), and the evaluation of these coarse-resolution SIF measurements using GPP derived from eddy covariance (EC) flux towers has been hindered by the scale mismatch between satellite and tower footprints. We use new far-red SIF observations from the Orbiting Carbon Observatory-2 (OCO-2) satellite with much finer spatial resolution and GPP data from EC flux towers from 2014 to 2016 to examine the relationship between GPP and SIF for temperate forests. The OCO-2 SIF tracked tower GPP fairly well, and had strong correlation with tower GPP at both retrieval bands (757nm and 771nm) and both instantaneous (mid-day) and daily timescales. Daily SIF at 757nm (SIF757) exhibited much stronger correlation with tower GPP compared to MODIS enhanced vegetation index (EVI) and normalized difference vegetation index (NDVI) derived from either Terra or Aqua and had a similarly strong relationship as EVI based on the bidirectional reflectance distribution function (BRDF) corrected reflectance product (Terra+Aqua). Absorbed photosynthetically active radiation (APAR) explained 85% of the variance in SIF757, while the product of APAR and two environmental scalars - fTmin and fVPD (representing minimum temperature stress and water stress) explained slightly higher variance (92%) in SIF757. This suggests that SIF mainly depends on APAR and also contains information on light use efficiency (LUE) reflecting environmental stresses and physiological or biochemical variations of vegetation. The hyperbolic model based on SIF757 estimated GPP well (R2=0.81, pmodel - the MODSI GPP algorithm. Our findings demonstrate the strong

  9. A drilling rig tower

    Energy Technology Data Exchange (ETDEWEB)

    Mironov, A.A.; Barashkov, V.A.; Bulgakov, E.S.; Kuldoshin, I.P.; Lebedev, A.I.; Papin, N.M.; Rebrik, B.M.; Sirotkin, N.V.

    1981-05-23

    Presentation is made of a drilling rig tower, comprising a gantry, a support shaft with a bracing strut and drawings out, and turn buckles. In order to increase the reliability of the tower in operation, to decrease the over all dimensions in a transport position, and to decrease the amount of time taken to transfer the tower from an operational position into a transportable one, and vice versa, the tower is equipped with a rotary frame made in the form of a triangular prism, whose lateral edges are connected by hinges: the first one with the lower part of the support shaft, the second with the gantry, and the third one to the upper part of the support shaft by means of the drawings out. The large boundary of the rotary frame is connected by a hinge to the support shaft by means of a bracing strut, which is equipped with a slide block connected to it by a hinge, and the rotary frame has a guide for the slide block reinforced to it on the large boundary. Besides this, the lateral edge of the rotary frame is connected to the gantry by means of turn buckles.

  10. The Design of Akhmat Tower

    Science.gov (United States)

    Beardsley, Sara; Stochetti, Alejandro; Cerone, Marc

    2018-03-01

    Akhmat Tower is a 435m supertall building designed by Adrian Smith + Gordon Gill Architecture. It is currently under construction in the city of Grozny, in the Chechen Republic, in the North Caucasus region of Russia. The design of the tower was done during a collaborative process by a multi-disciplinary architectural and engineering team, based primarily in the United States and Russia. During this process, the designers considered many factors including, most primarily, the cultural and historical context, the structural requirements given the high seismicity of the region, and the client's programmatic needs. The resulting crystalline-shaped tower is both an aesthetic statement and a performative architectural solution which will be a new landmark for Chechnya. "The Design of Akhmat Tower" describes in detail the design process including structural considerations, exterior wall design, building program, interior design, the tuned mass damper, and the use of building information modeling.

  11. Study on Tower Models for EHV Transmission Line

    Directory of Open Access Journals (Sweden)

    Xu Bao-Qing

    2016-01-01

    Full Text Available Lightning outage accident is one of the main factors that threat seriously the safe and reliable operation of power system. So it is very important to establish reasonable transmission tower model and evaluate the impulse response characteristic of lightning wave traveling on the transmission tower properly for determining reliable lightning protection performance. With the help of Electromagnetic Transient Program (EMTP, six 500kV tower models are built. Aiming at one line to one transformer operating mode of 500kV substation, the intruding wave overvoltage under different tower models is calculated. The effect of tower model on intruding overvoltage has been studied. The results show that different tower models can result in great differences to the calculation results. Hence, reasonable selection of the tower model in the calculation of back- strike intruding wave is very important.

  12. Coagulation chemistries for silica removal from cooling tower water.

    Energy Technology Data Exchange (ETDEWEB)

    Nyman, May Devan; Altman, Susan Jeanne; Stewart, Tom

    2010-02-01

    The formation of silica scale is a problem for thermoelectric power generating facilities, and this study investigated the potential for removal of silica by means of chemical coagulation from source water before it is subjected to mineral concentration in cooling towers. In Phase I, a screening of many typical as well as novel coagulants was carried out using concentrated cooling tower water, with and without flocculation aids, at concentrations typical for water purification with limited results. In Phase II, it was decided that treatment of source or make up water was more appropriate, and that higher dosing with coagulants delivered promising results. In fact, the less exotic coagulants proved to be more efficacious for reasons not yet fully determined. Some analysis was made of the molecular nature of the precipitated floc, which may aid in process improvements. In Phase III, more detailed study of process conditions for aluminum chloride coagulation was undertaken. Lime-soda water softening and the precipitation of magnesium hydroxide were shown to be too limited in terms of effectiveness, speed, and energy consumption to be considered further for the present application. In Phase IV, sodium aluminate emerged as an effective coagulant for silica, and the most attractive of those tested to date because of its availability, ease of use, and low requirement for additional chemicals. Some process optimization was performed for coagulant concentration and operational pH. It is concluded that silica coagulation with simple aluminum-based agents is effective, simple, and compatible with other industrial processes.

  13. Performance characteristics of counter flow wet cooling towers

    International Nuclear Information System (INIS)

    Khan, Jameel-Ur-Rehman; Yaqub, M.; Zubair, Syed M.

    2003-01-01

    Cooling towers are one of the biggest heat and mass transfer devices that are in widespread use. In this paper, we use a detailed model of counter flow wet cooling towers in investigating the performance characteristics. The validity of the model is checked by experimental data reported in the literature. The thermal performance of the cooling towers is clearly explained in terms of varying air and water temperatures, as well as the driving potential for convection and evaporation heat transfer, along the height of the tower. The relative contribution of each mode of heat transfer rate to the total heat transfer rate in the cooling tower is established. It is demonstrated with an example problem that the predominant mode of heat transfer is evaporation. For example, evaporation contributes about 62.5% of the total rate of heat transfer at the bottom of the tower and almost 90% at the top of the tower. The variation of air and water temperatures along the height of the tower (process line) is explained on psychometric charts

  14. Atmospheric cooling tower with reduced plume

    International Nuclear Information System (INIS)

    Gautier, D.M.; Lagoutte, A.

    1985-01-01

    The cooling tower, usable in thermal-electric power plants, has a vertical chimney having a central water tower fed with water to be cooled, a pipe network distributing water coming from the water tower and dispersing it in flows streaming down on a packing, and a basin to receive the water cooled by contact with an air flow passing through apertures at the lower part of the chimney and flowing up through the chimney. The cooling tower has inlet air pipes for the said apertures to a zone of the chimney situated beyond the streaming zone, the said pipes being arranged such their surface is swept by water to be cooled [fr

  15. EVALUATING THE COSTS OF PACKED-TOWER AERATION AND GAC FOR CONTROLLING SELECTED ORGANICS

    Science.gov (United States)

    This article focuses on a preliminary cost analysis that compares liquid-phase granular activated carbon (GAC) treatment with packed-tower aeration (PTA) treatment, with and without air emissions control. The sensitivity of cost to design and operating variables is also discussed...

  16. Emission of asbestos fibres from natural-draught cooling towers. Pt. 1 and 2

    International Nuclear Information System (INIS)

    Ernst, G.; Althaus, E.; Karotke, E.; Grimm, K.; Heumann, H.G.; Rueckert, G.

    1985-01-01

    Sampling for the studies reported has been done in a relatively new nuclear power plant with natural-draught, wet cooling tower, and in an older, brown-coal fired power plant with the same type of cooling towers, both towers equipped with internal structures made of asbestos cement. Samples have been taken from the plumes, air in the environment, cooling water receiving tank, make-up water. The samples have been primarily examined for their content of asbestos fibres. The results show that relatively few asbestos is found in the environmental air and in the cooling water receiving tank. Putting it continuously, it can be said that the cooling water entrains only little amounts of the asbestos of the internal structures. The plume samples indicate emission of some thousand asbestos fibres per m 3 , or less than 1 ng. Taking into account one sample exhibiting an extremely high amount of asbestos, the average emission of asbestos fibres with the plumes is 10 6 fibres per m 3 , or 100 ng/m 3 of plume. The maximum air pollution thus calculated in accordance with TA Luft (Clean Air Technical Directive), for the less favourable weather conditions at a hight of 2 m above ground, is 10 fibres per one m 3 of air; including the extreme data of the single sample mentioned above, the result is some thousand fibres per m 3 . The data are far below the TRK data (Technical guiding data for maximum concentration at the place of work), which state a maximum of 10 6 fibres per m 3 . (orig.) [de

  17. Numerical research of a super-large cooling tower subjected to accidental loads

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yi; Lin, Feng [Department of Building Engineering, Tongji University, Shanghai 200092 (China); Gu, Xianglin, E-mail: gxl@tongji.edu.cn [Department of Building Engineering, Tongji University, Shanghai 200092 (China); Lu, Xiaoqin [Guangdong Electric Power Design Institute, Guangzhou 510660 (China)

    2014-04-01

    With the continued development of nuclear power plants, more and more super-large cooling towers are to be built in China and around the world. For the safe operation of nuclear power plants, research work has been done on the causes of collapse of cooling towers, collapse modes and the secondary disasters caused by the collapse of cooling towers. However, the collapse modes and the ground vibration induced by the collapse of cooling towers subjected to the accidental loads have not been fully understood. This paper has been focused on the modes and mechanisms behavior of the collapse of cooling towers subjected to accidental loads. Meanwhile, prediction of the ground vibration due to the collapse of the cooling towers has also been completed in a parallel project. Using dynamic finite element program LS-DYNA, a 3D finite element model for a super-large cooling tower was developed and the nonlinear material models were incorporated. In this paper, four types of accidental loads were considered to trigger the collapse or local failure of the tower, including vehicle collision, airplane impact, local explosion and missile attack. It was found that vehicle collision, missile attack and small TNT equivalent explosives (2 kg, 20 kg, 200 kg) might result in local failure of the cooling tower, however, the tower can still keep stable. On the other hand, large TNT equivalent explosives (2000 kg, 4500 kg) could cause severe damages in the inclined columns of the cooling tower, and lead to progressive collapse of the entire cooling tower. The two kinds of TNT equivalent explosives caused the same collapse mode while the collapsing duration was different. The airplane impacted at the throat of the cooling tower caused the local failure of shell structure of the tower, and then the progressive collapse of the cooling tower happened due to the gravitational action. The resulting collapse mode was different from that triggered by the local explosion.

  18. Numerical research of a super-large cooling tower subjected to accidental loads

    International Nuclear Information System (INIS)

    Li, Yi; Lin, Feng; Gu, Xianglin; Lu, Xiaoqin

    2014-01-01

    With the continued development of nuclear power plants, more and more super-large cooling towers are to be built in China and around the world. For the safe operation of nuclear power plants, research work has been done on the causes of collapse of cooling towers, collapse modes and the secondary disasters caused by the collapse of cooling towers. However, the collapse modes and the ground vibration induced by the collapse of cooling towers subjected to the accidental loads have not been fully understood. This paper has been focused on the modes and mechanisms behavior of the collapse of cooling towers subjected to accidental loads. Meanwhile, prediction of the ground vibration due to the collapse of the cooling towers has also been completed in a parallel project. Using dynamic finite element program LS-DYNA, a 3D finite element model for a super-large cooling tower was developed and the nonlinear material models were incorporated. In this paper, four types of accidental loads were considered to trigger the collapse or local failure of the tower, including vehicle collision, airplane impact, local explosion and missile attack. It was found that vehicle collision, missile attack and small TNT equivalent explosives (2 kg, 20 kg, 200 kg) might result in local failure of the cooling tower, however, the tower can still keep stable. On the other hand, large TNT equivalent explosives (2000 kg, 4500 kg) could cause severe damages in the inclined columns of the cooling tower, and lead to progressive collapse of the entire cooling tower. The two kinds of TNT equivalent explosives caused the same collapse mode while the collapsing duration was different. The airplane impacted at the throat of the cooling tower caused the local failure of shell structure of the tower, and then the progressive collapse of the cooling tower happened due to the gravitational action. The resulting collapse mode was different from that triggered by the local explosion

  19. Thermodynamic and dynamic ice thickness contributions in the Canadian Arctic Archipelago in NEMO-LIM2 numerical simulations

    Science.gov (United States)

    Hu, Xianmin; Sun, Jingfan; Chan, Ting On; Myers, Paul G.

    2018-04-01

    Sea ice thickness evolution within the Canadian Arctic Archipelago (CAA) is of great interest to science, as well as local communities and their economy. In this study, based on the NEMO numerical framework including the LIM2 sea ice module, simulations at both 1/4 and 1/12° horizontal resolution were conducted from 2002 to 2016. The model captures well the general spatial distribution of ice thickness in the CAA region, with very thick sea ice (˜ 4 m and thicker) in the northern CAA, thick sea ice (2.5 to 3 m) in the west-central Parry Channel and M'Clintock Channel, and thin ( Program data at first-year landfast ice sites except at the northern sites with high concentration of old ice. At 1/4 to 1/12° scale, model resolution does not play a significant role in the sea ice simulation except to improve local dynamics because of better coastline representation. Sea ice growth is decomposed into thermodynamic and dynamic (including all non-thermodynamic processes in the model) contributions to study the ice thickness evolution. Relatively smaller thermodynamic contribution to ice growth between December and the following April is found in the thick and very thick ice regions, with larger contributions in the thin ice-covered region. No significant trend in winter maximum ice volume is found in the northern CAA and Baffin Bay while a decline (r2 ≈ 0.6, p < 0.01) is simulated in Parry Channel region. The two main contributors (thermodynamic growth and lateral transport) have high interannual variabilities which largely balance each other, so that maximum ice volume can vary interannually by ±12 % in the northern CAA, ±15 % in Parry Channel, and ±9 % in Baffin Bay. Further quantitative evaluation is required.

  20. Cooling tower drift: comprehensive case study

    International Nuclear Information System (INIS)

    Laulainen, N.S.; Ulanski, S.L.

    1979-01-01

    A comprehensive experiment to study drift from mechanical drift cooling towers was conducted during June 1978 at the PG and E Pittsburg Power Plant. The data from this study will be used for validation of drift deposition models. Preliminary results show the effects of tower geometry and orientation with respect to the wind and to single- or two-tower operation. The effect of decreasing relative humidity during a test run can also be seen

  1. EFFECT OF THE FILL VENTILATION WINDOW ON PERFORMANCE OF A NATURAL DRAFT COOLING TOWER SUBJECTED TO CROSS-WINDS

    Directory of Open Access Journals (Sweden)

    K. V. Dobrego

    2016-01-01

    Full Text Available Various aerodynamic design elements and technics (wind deflectors, wind walls, etc. are utilized for improvement of the thermal efficiency of the natural draft cooling towers, particularly in conditions of cross wind. One of the technical methods, proposed by engineers of Belarus Academy of Sciences, is installation of the ventilation window in the center of the fill. This method is substantiated by the fact that the flow of cooling gas obtains maximum temperature and humidity near the center of the under-fill space of cooling tower and, as a consequence, performs minimal heat exchange. The influence of the fill ventilation window and wind deflectors in the inlet windows of the cooling tower on its thermal performance in condition of cross-wind is investigated in the paper numerically. The cooling tower of the “Woo-Jin” power plant (China 150 m of the height and 114 m of the base diameter was taken as a prototype. The analogy (equivalence between the heat and mass transfer was taken into consideration, which enabled us to consider single-phase flow and perform complicated 3D simulation by using modern personal computers. Heat transfer coefficient for the fill and its hydrodynamic resistance were defined by using actual data on total flow rate in the cooling tower. The numerical model and computational methods were tested and verified in numerous previous works. The non-linear dependence of the thermal performance of the cooling tower on wind velocity (with the minimum in vicinity of Ucr ~ 8 m/s for the simulated system was demonstrated. Calculations show that in the condition of the average wind speed the fill ventilation window doesn’t improve, but slightly decrease (by 3–7 % performance of the cooling tower. Situation changes in the condition of strong winds Ucw > 12 m/s, which are not typical for Belarus. Utilization of airflow deflectors at the inlet windows of cooling tower, conversely, increases thermal performance of the

  2. Control Towers in Supply Chain Management - Past and Future

    Directory of Open Access Journals (Sweden)

    Anna Trzuskawska-Grzesińska

    2017-02-01

    Full Text Available The global economy requires global supply chain management which relies on visibility and responsiveness. Determinants such as: information technology tools, process knowledge, sales and operations planning experiences, etc., enable the formation of theory and practice for the supply chain control tower concept. The goal of the research paper is to identify business examples of different approaches to the supply chain control tower in the past and initiate a discussion on their future. This paper synthesizes past control tower practices and identifies possible future trends. The author performed: literature analysis, three selected companies' case studies and comparative analyses. As the control towers evolve, while supply chains are transforming continuous, update from the market is needed. The research findings showed the selected companies, in the future, perceived control tower's activities as a potential source of revenue not just solely a source of cost and time optimization as well as a source of value added to customer. The researched control towers were built and still they are developed. The business frequently changes and requires control towers to be adjusted, reengineered and adaptive. The researched control towers are needed to keep control over supply chain while it is transforming. There is a differentiation between the supply chain control towers, logistic services control towers and reverse supply chain control towers. An integration mechanism between the control towers would be necessary to assure entire supply chain visibility and orchestration. The research also shows the knowledge gap regarding the control towers in supply chain, specially their possible configurations and future.

  3. AUTOMATED DEAD-END ULTRAFILTRATION FOR ENHANCED SURVEILLANCE OF LEGIONELLA 2 PNEUMOPHILA AND LEGIONELLA SPP. IN COOLING TOWER WATERS

    Energy Technology Data Exchange (ETDEWEB)

    Brigmon, R.; Leskinen, S.; Kearns, E.; Jones, W.; Miller, R.; Betivas, C.; Kingsley, M.; Lim, D.

    2011-10-10

    Detection of Legionella pneumophila in cooling towers and domestic hot water systems involves concentration by centrifugation or membrane filtration prior to inoculation onto growth media or analysis using techniques such as PCR or immunoassays. The Portable Multi-use Automated Concentration System (PMACS) was designed for concentrating microorganisms from large volumes of water in the field and was assessed for enhancing surveillance of L. pneumophila at the Savannah River Site, SC. PMACS samples (100 L; n = 28) were collected from six towers between August 2010 and April 2011 with grab samples (500 ml; n = 56) being collected before and after each PMACS sample. All samples were analyzed for the presence of L. pneumophila by direct fluorescence immunoassay (DFA) using FITC-labeled monoclonal antibodies targeting serogroups 1, 2, 4 and 6. QPCR was utilized for detection of Legionella spp. in the same samples. Counts of L. pneumophila from DFA and of Legionella spp. from qPCR were normalized to cells/L tower water. Concentrations were similar between grab and PMACS samples collected throughout the study by DFA analysis (P = 0.4461; repeated measures ANOVA). The same trend was observed with qPCR. However, PMACS concentration proved advantageous over membrane filtration by providing larger volume, more representative samples of the cooling tower environment, which led to reduced variability among sampling events and increasing the probability of detection of low level targets. These data highlight the utility of the PMACS for enhanced surveillance of L. pneumophila by providing improved sampling of the cooling tower environment.

  4. Deformation of stages of exchange tower 12T1 - a case study (Paper No. 2.9)

    International Nuclear Information System (INIS)

    Gulati, B.S.

    1992-01-01

    Heavy Water Plant at Baroda is based on monothermal hydrogen ammonia exchange process. Exchange tower-12 T1 is the biggest vessel in the plant and has 12 exchange stages and a cable stage. During the annual shut-down in April-May 1991, tower was opened for maintenance when the 12th stage was lifted, frosting/icing was observed on its outer shell with some reported ammonia smell. This paper describes the incident, deformation of stages of exchange tower, possible causes of dent formation and also elaborates the remedial measures taken. (author). 6 figs

  5. Membrane distillation of industrial cooling tower blowdown water

    Directory of Open Access Journals (Sweden)

    N.E. Koeman-Stein

    2016-06-01

    Full Text Available The potential of membrane distillation for desalination of cooling tower blowdown water (CTBD is investigated. Technical feasibility is tested on laboratory and pilot scale using real cooling tower blowdown water from Dow Benelux in Terneuzen (Netherlands. Two types of membranes, polytetrafluorethylene and polyethylene showed good performance regarding distillate quality and fouling behavior. Concentrating CTBD by a factor 4.5 while maintaining a flux of around 2 l/m2*h was possible with a water recovery of 78% available for reuse. Higher concentration factors lead to severe decrease in flux which was caused by scaling. Membrane distillation could use the thermal energy that would otherwise be discharged of in a cooling tower and function as a heat exchanger. This reduces the need for cooling capacity and could lead to a total reduction of 37% water intake for make-up water, as well as reduced energy and chemicals demands and greenhouse gas emissions.

  6. Analysis of a back flashover across insulator strings on a 115 kV transmission line tower by PSCAD

    Directory of Open Access Journals (Sweden)

    Worakit Anekthanasuwan

    2015-09-01

    Full Text Available Lightning striking on a transmission tower induces high ground potential rise and high voltage at tower arms in which potential is normally at ground level, and subsequently causes overvoltage across an insulator string. If this overvoltage is higher than the withstanding voltage of the insulator string according to the v-t (voltage-time curve, back flashover phenomena will occur and this event may cause outage. The main objective of this paper is to study the factors influencing the back flashover phenomena. The computer program PSCAD/EMTDC (Power System Computer Aided Design/Electromagnetic Transients including DC is used to simulate lightning striking on a transmission tower 115kV. Lightning current, transmission towers, ground resistance, insulator strings and back flashover phenomena are modeled. Main simulations are lightning striking on different towers, different soil resistivity, different lightning current magnitudes and wave shapes, different locations, and different phase angles of source voltage. Simulation results show that the higher tower encounters higher induced voltage. A back flashover occurs at the top tower arm easier than at the middle and lower arms. The higher soil resistivity induces higher voltage. The larger lightning current magnitude impacts on higher induced voltage. The longer rise time of lightning current generates lower induced voltage. Lightning strikes directly on tower generate higher voltage than that of striking on overhead ground wires.

  7. Improving performance and reducing costs of cooling towers

    International Nuclear Information System (INIS)

    Bartz, J.A.

    1992-01-01

    Cooling towers represent a significant capital investment at a steam electric power station. In addition, deficiencies in thermal performance can result in major operating penalties of fuel cost, replacement energy, and capacity addition. This paper summarizes two recent EPRI research projects aimed at reducing thermal performance deficiencies and decreasing installed costs of evaporative cooling towers. First, EPRI Research Project 2113, Cooling Tower Performance Prediction and Improvement, is summarized. This project has resulted in published data sets on the measured thermal performance characteristics of a variety of cooling tower packings, computer codes to predict tower performance, and computer code validation through large-scale tower performance measurements. Principal results are contained in an EPRIGEMS software module, Cooling Tower Advisor. This PC- based software contains a tutorial plus codes to predict tower thermal performance, arranged in a user-friendly format. The second EPRI effort, Research Project 2819-10/11, Fabric Structures for Power Plant Applications, has resulted in designs and costs of large structures with shells constructed of recently-developed fabrics. Primary power plant applications for such structures are the shells of natural draft cooling towers and coal-pile covers. Fabric structures offer low initial cost, acceptable life, and seismic superiority, among other advantages. Detailed conceptual designs and installed cost data are reviewed. 8 refs., 9 figs., 3 tabs

  8. Biofouling control of industrial seawater cooling towers

    KAUST Repository

    Al-Bloushi, Mohammed

    2017-01-01

    In this study, the research focuses on biofouling control in seawater cooling towers by investigating two different approaches. The first strategy addresses the use of alternative oxidants (i.e. ozone micro-bubbles and chlorine dioxide) in treatment of cooling towers. The second strategy investigates removing nutrients in seawater using granular activated carbon filter column and ultrafiltration to prevent the growth of microorganisms. Laboratory bench-scale tests in terms of temperature, cycle of concentration, dosage, etc. indicated that, at lower oxidant dosages (total residual oxidant (TRO) equivalent = 0.1 mg/l Cl2), chlorine dioxide had a better disinfection effect than chlorine and ozone. The performance of oxidizing biocides at pilot scale, operating at assorted conditions, showed that for the disinfectants tested, ozone could remove 95 % bioactivity of total number of bacteria and algae followed by chlorine dioxide at 85%, while conventional chlorine dosing only gave 60% reduction in bioactivities. Test results of GAC bio-filter showed that around 70 % removal of total organic carbon in the seawater feed was achieved and was effective in keeping the microbial growth to a minimum. The measured results from this study enable designers of seawater cooling towers to manage the biofouling problems when such cooling towers are extrapolated to a pilot scale.

  9. Quantifying the local influence at a tall tower site in nocturnal conditions

    Energy Technology Data Exchange (ETDEWEB)

    Werth, David; Buckley, Robert; Zhang, Gengsheng; Kurzeja, Robert; Leclerc, Monique; Duarte, Henrique; Parker, Matthew; Watson, Thomas

    2015-10-17

    The influence of the local terrestrial environment on nocturnal atmospheric CO2 measurements at a 329-m television transmitter tower (and a component of a CO2 monitoring network) was estimated with a tracer release experiment and a subsequent simulation of the releases. This was done to characterize the vertical transport of emissions from the surface to the uppermost tower level and how it is affected by atmospheric stability. The tracer release experiment was conducted over two nights in May of 2009 near the Department of Energy’s Savannah River Site (SRS) in South Carolina. Tracer was released on two contrasting nights—slightly stable and moderately stable—from several upwind surface locations. Measurements at the 329-m level on both nights indicate that tracer was able to mix vertically within a relatively short (~24 km) distance, implying that nocturnal stable conditions do not necessarily prevent vertical dispersion in the boundary layer and that CO2 measurements at the tower are at least partly influenced by nearby emissions. A simulation of the tracer release is used to calculate the tower footprint on the two nights to estimate the degree to which the local domain affects the tower readings. The effect of the nocturnal boundary layer on the area sampled by the tower can be seen clearly, as the footprints were affected by changes in stability. The contribution of local sources to the measurements at the tower was minimal, however, suggesting that nocturnal concentrations at upper levels are contributed mostly by regional sources.

  10. Analysis of Ideal Towers for Tall Wind Applications

    Energy Technology Data Exchange (ETDEWEB)

    Dykes, Katherine L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Damiani, Rick R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Roberts, Joseph O [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Lantz, Eric J [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-01-12

    Innovation in wind turbine tower design is of significant interest for future development of wind power plants. First, wind turbine towers account for a large portion of overall capital expenditures for wind power projects. Second, for low wind-resource regions of the world, the use of low-cost tall-tower technology has the potential to open new markets for development. This study investigates the relative potential of various tower configurations in terms of mass and cost. For different market applications and hub heights, idealized tall towers are designed and compared. The results show that innovation in wind turbine controls makes reaching higher hub heights with current technology economically viable. At the same time, new technologies hold promise for reducing tower costs as these technologies mature and hub heights reach twice the current average.

  11. Cooling towers for thermal power plants

    International Nuclear Information System (INIS)

    Chaboseau, J.

    1987-01-01

    After a brief recall on cooling towers testing and construction, this paper presents four examples of very large French nuclear power plant cooling towers, and one of an Australian thermal power plant [fr

  12. A tower structured scintillator-lead photon calorimeter using a novel fiber optics readout system

    International Nuclear Information System (INIS)

    Fessler, H.; Freund, P.; Gebauer, J.; Glas, K.M.; Pretzl, K.P.; Seyboth, P.; Seyerlein, J.; Thevenin, J.C.

    1984-06-01

    Described is the construction and the performance of a tower structured scintillator-lead photon calorimeter using a novel fiber optics readout system. The calorimeter is divided into 9 individual towers. Each tower has a cross section of 5x5 cm 2 and consists of 60 layers of 2 mm lead plus 5 mm thick scintillator. The four sides of each tower are covered by thin acrylic sheets (1.5 mm thick) doped with a wavelength shifting material. The light produced in each scintillator plate is first converted in these sheets, then converted a second time in a set of polystyrene optical fibers (diameter 2 mm) which run longitudinally through the calorimeter along the corners of each tower. A small diameter photomultiplier was attached to the fibers at the back end of the calorimeter. The obtained energy resolution with incident electrons in the range of 0.25 - 5.0 GeV/c is sigma/E = 0.10/√E. The uniformity of response across the front face of each tower was measured. (orig.)

  13. Lifting system and apparatus for constructing wind turbine towers

    Science.gov (United States)

    Livingston, Tracy; Schrader, Terry; Goldhardt, James; Lott, James

    2011-02-01

    The disclosed invention is utilized for mounting a wind turbine and blade assembly on the upper end of a wind turbine tower. The invention generally includes a frame or truss that is pivotally secured to the top bay assembly of the tower. A transverse beam is connected to the frame or truss and extends fore of the tower when the frame or truss is in a first position and generally above the tower when in a second position. When in the first position, a wind turbine or blade assembly can be hoisted to the top of the tower. The wind turbine or blade assembly is then moved into position for mounting to the tower as the frame or truss is pivoted to a second position. When the turbine and blade assembly are secured to the tower, the frame or truss is disconnected from the tower and lowered to the ground.

  14. The Schmehausen cable net cooling tower

    International Nuclear Information System (INIS)

    Schlaich, J.; Mayr, G.; Weber, P.; Jasch, E.

    1976-01-01

    The prototype of a large cable net shell as a natural-draught cooling tower for the THTR-300 is presented. Results of wind tunnel tests and calculations are given, and the capacity is discussed. Design features of the main components are presented in illustrations and are described with regard to the construction process of the cooling tower. Finally, it is shown that the cable net cooling tower is a suitable construction for large dimensions and caving-in or seismic areas. (orig./HP) [de

  15. IMPROVEMENT OF SYSTEMS OF TECHNICAL WATER SUPPLY WITH COOLING TOWERS FOR HEAT POWER PLANTS TECHNICAL AND ECONOMIC INDICATORS PERFECTION. Part 2

    Directory of Open Access Journals (Sweden)

    Yu. A. Zenovich-Leshkevich-Olpinskiy

    2016-01-01

    Full Text Available The method of calculation of economic efficiency that can be universal and is suitable for feasibility study of modernization of irrigation and water distribution system of cooling towers has been developed. The method takes into account the effect of lower pressure exhaust steam in the condenser by lowering the temperature of the cooling water outlet of a cooling tower that aims at improvement of technical and economic indicators of heat power plants. The practical results of the modernization of irrigation and water distribution system of a cooling tower are presented. As a result, the application of new irrigation and water distribution systems of cooling towers will make it possible to increase the cooling efficiency by more than 4 оС and, therefore, to obtain the fuel savings by improving the vacuum in the turbine condensers. In addition, the available capacity of CHP in the summer period is increased. The results of the work, the experience of modernization of irrigation and water distribution systems of the Gomel CHP-2 cooling towers system, as well as the and methods of calculating of its efficiency can be disseminated for upgrading similar facilities at the power plants of the Belarusian energy system. Some measures are prosed to improve recycling systems, cooling towers and their structures; such measures might significantly improve the reliability and efficiency of technical water supply systems of heat power plants.

  16. Performance characteristics of a shower cooling tower

    International Nuclear Information System (INIS)

    Qi Xiaoni; Liu Zhenyan; Li Dandan

    2007-01-01

    This study was prompted by the need to design towers for applications in which, due to salt deposition on the packing and subsequent blockage, the use of tower packing is not practical. In contrast to conventional cooling towers, the cooling tower analyzed in this study is void of fill. By means of efficient atomization nozzles, a shower cooling tower (SCT) is possible to be applied in industry, which, in terms of water cooling, energy saving and equipment investing, is better than conventional packed cooling towers. However, no systematic thermodynamic numerical method could be found in the literature up to now. Based on the kinetic model and mass and heat transfer model, this paper has developed a one dimensional model for studying the motional process and evaporative cooling process occurring at the water droplet level in the SCT. The finite difference approach is used for three motional processes to obtain relative parameters in each different stage, and the possibility of the droplets being entrained outside the tower is fully analyzed. The accuracy of this model is checked by practical operational results from a full scale prototype in real conditions, and some exclusive factors that affect the cooling characteristics for the SCT are analyzed in detail. This study provides the theoretical foundation for practical application of the SCT in industry

  17. Atmospheric emissions from power plant cooling towers

    International Nuclear Information System (INIS)

    Micheletti, W.

    2006-01-01

    Power plant recirculated cooling systems (cooling towers) are not typically thought of as potential sources of air pollution. However, atmospheric emissions can be important considerations that may influence cooling tower design and operation. This paper discusses relevant U.S. environmental regulations for potential atmospheric pollutants from power plant cooling towers, and various methods for estimating and controlling these emissions. (orig.)

  18. Assessment of cooling tower impact

    International Nuclear Information System (INIS)

    1986-01-01

    This guideline describes the state of the art of the meteorological impact of wet cooling towers that are about 80 m to 170 m high, and have a waste heat power in the range of 1000 MW and 2500 MW. The physical processes occurring in the lowest layer of the atmosphere and their impact in the dispersion of cooling tower emissions are represented. On the basis of these facts, the impact on weather or climate in the vicinity of a high wet cooling tower is estimated. Thereby the results of the latest investigations (observations, measurements, and modeling) on the different locations of plants as well as their different power and construction types are taken into consideration. (orig.) [de

  19. Tall towers for large wind turbines. Report from Vindforsk project V-342

    Energy Technology Data Exchange (ETDEWEB)

    Engstroem, Staffan; Lyrner, Tomas; Hassanzadeh, Manouchehr; Stalin, Thomas; Johansson, John

    2010-07-15

    The general rule of thumb has been to furnish a wind turbine with a tower as tall as the turbine diameter, with deviations downwards for high wind speed sites. In this report the statement is questioned, with special emphasis for wind turbines sited in forests. The aim of this project was to propose and calculate candidate types of tall towers for on-shore wind turbines in the 3 - 5 MW range, with special reference to siting in forests with a representative wind shear. During the project this scope has been more precisely defined to study 3 and 5 MW wind turbines with hub heights of 80 - 175 meters featuring the following tower solutions: 1. Steel shell tower designed in a conventional way with flanges and both longitudinal and transverse welds. 2. Steel shell tower with bolted friction joints only. 3. Concrete tower with pretensioned steel tendons. 4. Hybrid tower with a lower concrete part and an upper part built as a conventional steel shell. 5. Lattice tower. 6. Wooden tower. During the execution of the project the design of a total of 42 towers was outlined and calculated. Today the welded steel shell tower dominates the wind turbine market. Larger turbines and higher hub heights result in larger optimal tower base diameters. For the road transportation there are limitations due to bridges and other obstacles. In Sweden the limit for transports with special permits in general maximizes the diameter to 4,5 metres. To some extent it is still technically possible to build towers with a less than optimal diameter, but due to the high mass and the large wall thickness they tend to be uneconomical in comparison with other alternatives above a hub height of roughly 100 metres. In this report welded steel shell towers were outlined for 3 MW turbines up to a hub height of 150 metres whereas the limit for the 5 MW towers was 100 metres. When diameter restrictions tend to make welded towers uneconomical, the next logical choice is steel shell towers with bolted friction

  20. Formation of secondary inorganic aerosols by power plant emissions exhausted through cooling towers in Saxony.

    Science.gov (United States)

    Hinneburg, Detlef; Renner, Eberhard; Wolke, Ralf

    2009-01-01

    The fraction of ambient PM10 that is due to the formation of secondary inorganic particulate sulfate and nitrate from the emissions of two large, brown-coal-fired power stations in Saxony (East Germany) is examined. The power stations are equipped with natural-draft cooling towers. The flue gases are directly piped into the cooling towers, thereby receiving an additionally intensified uplift. The exhausted gas-steam mixture contains the gases CO, CO2, NO, NO2, and SO2, the directly emitted primary particles, and additionally, an excess of 'free' sulfate ions in water solution, which, after the desulfurization steps, remain non-neutralized by cations. The precursor gases NO2 and SO2 are capable of forming nitric and sulfuric acid by several pathways. The acids can be neutralized by ammonia and generate secondary particulate matter by heterogeneous condensation on preexisting particles. The simulations are performed by a nested and multi-scale application of the online-coupled model system LM-MUSCAT. The Local Model (LM; recently renamed as COSMO) of the German Weather Service performs the meteorological processes, while the Multi-scale Atmospheric Transport Model (MUSCAT) includes the transport, the gas phase chemistry, as well as the aerosol chemistry (thermodynamic ammonium-sulfate-nitrate-water system). The highest horizontal resolution in the inner region of Saxony is 0.7 km. One summer and one winter episode, each realizing 5 weeks of the year 2002, are simulated twice, with the cooling tower emissions switched on and off, respectively. This procedure serves to identify the direct and indirect influences of the single plumes on the formation and distribution of the secondary inorganic aerosols. Surface traces of the individual tower plumes can be located and distinguished, especially in the well-mixed boundary layer in daytime. At night, the plumes are decoupled from the surface. In no case does the resulting contribution of the cooling tower emissions to PM10

  1. Mechanical Properties of UHPFRC Joint for FORIDA Wind Turbine Tower

    DEFF Research Database (Denmark)

    Sørensen, Eigil Verner

    FORIDA Development, Vestas and Aalborg University are currently undertaking the project “FORIDA Hybrid Towers – The towers for next generation of wind turbines”, aiming to develop a new wind turbine tower structure (The FORIDA Tower) for very tall turbines. The tower is going to be a hybrid of ma...

  2. 2D study of wind forces around multiple cooling towers using ...

    African Journals Online (AJOL)

    user

    above, a pure numerical study were done on three and five cooling towers (in ... Invent of high speed digital computer technology had enabled the solution of flow ... The purpose of this work was to present a new design method, which ...

  3. Concept of CFD model of natural draft wet-cooling tower flow

    Directory of Open Access Journals (Sweden)

    Hyhlík T.

    2014-03-01

    Full Text Available The article deals with the development of CFD model of natural draft wet-cooling tower flow. The physical phenomena taking place within a natural draft wet cooling tower are described by the system of conservation law equations along with additional equations. The heat and mass transfer in the counterflow wet-cooling tower fill are described by model [1] which is based on the system of ordinary differential equations. Utilization of model [1] of the fill allows us to apply commonly measured fill characteristics as shown by [2].The boundary value problem resulting from the fill model is solved separately. The system of conservation law equations is interlinked with the system of ordinary differential equations describing the phenomena occurring in the counterflow wet-cooling tower fill via heat and mass sources and via boundary conditions. The concept of numerical solution is presented for the quasi one dimensional model of natural draft wet-cooling tower flow. The simulation results are shown.

  4. Damping of wind turbine tower vibrations

    DEFF Research Database (Denmark)

    Brodersen, Mark Laier; Pedersen, Mikkel Melters

    Damping of wind turbine vibrations by supplemental dampers is a key ingredient for the continuous use of monopiles as support for offshore wind turbines. The present thesis consists of an extended summary with four parts and appended papers [P1-P4] concerning novel strategies for damping of tower...... dominated vibrations.The first part of the thesis presents the theoretical framework for implementation of supplemental dampers in wind turbines. It is demonstrated that the feasibility of installing dampers at the bottom of the tower is significantly increased when placing passive or semiactive dampers...... in a stroke amplifying brace, which amplifies the displacement across the damper and thus reduces the desired level of damper force. For optimal damping of the two lowest tower modes, a novel toggle-brace concept for amplifying the bending deformation of the tower is presented. Numerical examples illustrate...

  5. Legionella species colonization in cooling towers: risk factors and assessment of control measures.

    Science.gov (United States)

    Mouchtouri, Varvara A; Goutziana, Georgia; Kremastinou, Jenny; Hadjichristodoulou, Christos

    2010-02-01

    Cooling towers can be colonized by Legionella spp, and inhalation of aerosols generated by their operation may cause Legionnaires' disease in susceptible hosts. Environmental investigations of Legionnaires' disease outbreaks linked with cooling towers have revealed poorly maintained systems, lack of control measures, and failure of system equipment. The purpose of this study was to identify Legionella-contaminated cooling towers, identify risk factors for contamination, and assess the effectiveness of control measures. A total of 96 cooling towers of public buildings were registered and inspected, and 130 samples were collected and microbiologically tested. Microbiological test results were associated with characteristics of cooling towers, water samples, inspection results, and maintenance practices. Of the total 96 cooling towers examined, 47 (48.9%) were colonized by Legionella spp, and 22 (22.9%) required remedial action. A total of 65 samples (50.0%) were positive (> or = 500 cfu L(-1)), and 30 (23%) were heavily contaminated (> or = 10(4) cfu L(-1)). Of the 69 isolates identified, 55 strains (79.7.%) were L pneumophila. Legionella colonization was positively associated with the absence of training on Legionella control (relative risk [RR] = 1.66; P = .02), absence of regular Legionella testing (RR = 2.07: P = .002), absence of sunlight protection (RR = 1.63: P = .02), with samples in which the free residual chlorine level in the water sample was cooling towers (median, 17 years; interquartile range [IQR] =5.0 to 26.0 years) compared with noncolonized cooling towers (median age, 6 years; IQR =1.0 to 13.5 years). After the 22 legionellae-positive cooling towers were disinfected with chlorine, 2 (9%) of them remained positive for Legionella spp with a concentration > or = 1000 cfu L(-1). Cooling towers can be heavily colonized by Legionella spp and thus present a potential risk for infection. This study demonstrates the importance of a risk assessment and

  6. Modality analysis of anchored ion exchange tower using Ansys

    International Nuclear Information System (INIS)

    Li Liang; Lei Zeyong

    2008-01-01

    Ion exchange towers are exposed to serious damage in the event of earthquakes. It is very necessary to study the seismic resistance of ion exchange tower. A finite element model of anchored ion exchange tower was made by Ansys. The first 10 ranks of inherent frequencies were made out, and three-dimensional main vibratory model figures were drawn out. The maximal stress along x-axis and y-axis and the main displacement were found at the bottom part of the wall of tower junction with the pillars. It is concluded that the breakage of tower wall easily occurs at the bottom part of the wall of tower junction with the pillars. Therefore, it is very important to reinforce the junction of the tower body, and the strengthening plate should lie near the bottom of wall. (authors)

  7. Asbestos in cooling-tower waters. Final report

    International Nuclear Information System (INIS)

    Lewis, B.A.G.

    1979-03-01

    Water discharges from cooling towers constructed with asbestos fill were found to contain chrysotile--asbestos fibers at concentrations as high as 10 8 fibers/liter. The major source of these fibers, appears to be the components of the towers rather than the air drawn through the towers or the makeup water taken into the towers. Suggested mechanisms for the release of chrysotile fibers from cooling-tower fill include freeze-thaw cycles and dissolution of the cement due to acidic components of the circulating water. Ash- or other material-settling ponds were found to reduce asbestos-fiber concentrations in cooling-tower effluent. The literature reviewed did not support the case for a causal relationship between adverse human health effects and drinking water containing on the order of 10 6 chrysotile--asbestos fibers/liter; for this and other reasons, it is not presently suggested that the use of asbestos fill be discontinued. However, caution and surveillance are dictated by the uncertainties in the epidemiological studies, the absence of evidence for a safe threshold concentration in water, and the conclusive evidence for adverse effects from occupational exposure. It is recommended that monitoring programs be carried out at sites where asbestos fill is used; data from such programs can be used to determine whether any mitigative measures should be taken. On the basis of estimates made in this study, monitoring for asbestos in drift from cooling towers does not appear to be warranted

  8. Subring Depth, Frobenius Extensions, and Towers

    Directory of Open Access Journals (Sweden)

    Lars Kadison

    2012-01-01

    Full Text Available The minimum depth d(B,A of a subring B⊆A introduced in the work of Boltje, Danz and Külshammer (2011 is studied and compared with the tower depth of a Frobenius extension. We show that d(B,A < ∞ if A is a finite-dimensional algebra and Be has finite representation type. Some conditions in terms of depth and QF property are given that ensure that the modular function of a Hopf algebra restricts to the modular function of a Hopf subalgebra. If A⊇B is a QF extension, minimum left and right even subring depths are shown to coincide. If A⊇B is a Frobenius extension with surjective Frobenius, homomorphism, its subring depth is shown to coincide with its tower depth. Formulas for the ring, module, Frobenius and Temperley-Lieb structures are noted for the tower over a Frobenius extension in its realization as tensor powers. A depth 3 QF extension is embedded in a depth 2 QF extension; in turn certain depth n extensions embed in depth 3 extensions if they are Frobenius extensions or other special ring extensions with ring structures on their relative Hochschild bar resolution groups.

  9. ''Novel'' types of cooling towers for the power industry

    International Nuclear Information System (INIS)

    Mikyska, L.

    1991-01-01

    New types of cooling towers are beginning to be used abroad for the cooling circuits of nuclear power plants employing power generation units rated at 1,300 to 1,400 MW. These so-called water recovery cooling towers make use of natural draught without a droplet section. They are actually upgraded designs which were built in Europe as far back as 70 years ago. Because of the unsuitable materials then employed, these cooling towers fell into oblivion. Today, however, they are undergoing a renaissance. An upgraded design of these towers is described and compared with existing cooling towers with a droplet section. The feasibility of using these towers in Czechoslovak conditions is considered. (author)

  10. Summary of tower designs for large horizontal axis wind turbines

    Science.gov (United States)

    Frederick, G. R.; Savino, J. M.

    1986-01-01

    Towers for large horizontal axis wind turbines, machines with a rotor axis height above 30 meters and rated at more than 500 kW, have varied in configuration, materials of construction, type of construction, height, and stiffness. For example, the U.S. large HAWTs have utilized steel truss type towers and free-standing steel cylindrical towers. In Europe, the trend has been to use only free-standing and guyed cylindrical towers, but both steel and reinforced concrete have been used as materials of construction. These variations in materials of construction and type of construction reflect different engineering approaches to the design of cost effective towers for large HAWTs. Tower designs are the NASA/DOE Mod-5B presently being fabricated. Design goals and requirements that influence tower configuration, height and materials are discussed. In particular, experiences with United States large wind turbine towers are elucidated. Finally, current trends in tower designs for large HAWTs are highlighted.

  11. Newton slopes for Artin-Schreier-Witt towers

    DEFF Research Database (Denmark)

    Davis, Christopher; Wan, Daqing; Xiao, Liang

    2016-01-01

    We fix a monic polynomial f(x)∈Fq[x] over a finite field and consider the Artin-Schreier-Witt tower defined by f(x); this is a tower of curves ⋯→Cm→Cm−1→⋯→C0=A1, with total Galois group Zp. We study the Newton slopes of zeta functions of this tower of curves. This reduces to the study of the Newton...... slopes of L-functions associated to characters of the Galois group of this tower. We prove that, when the conductor of the character is large enough, the Newton slopes of the L-function form arithmetic progressions which are independent of the conductor of the character. As a corollary, we obtain...

  12. Dynamic simulation and optimization of an industrial-scale absorption tower for CO2 capturing from ethane gas

    Directory of Open Access Journals (Sweden)

    Babak Pouladi

    2016-11-01

    Full Text Available This article considers a process technology based on absorption for CO2 capturing of ethane gas in phase 9 and 10 of south pars in Iran using diethanolamine (DEA as absorbent solvent. This CO2 capture plant was designed to achieve 85% CO2 recovery and obtain 19 ppm the CO2 concentration in the outlet of absorber. ASPEN–HYSYS software was used for the dynamic simulation of a commercial-scale CO2 capture plant and amine Pkg equation was chosen from the fluid property package for calculating the thermodynamic properties of the process. A static approach for optimization was used to evaluate the optimum conditions. This research revealed that pressure variation does not have any considerable changes in the absorption process, while both amine inlet temperature and volumetric flow rate increment enhance the absorption tower efficiency. The effect of temperature was very significant as shown in the dynamic study plots. The optimum condition for CO2 absorption from a stream of ethane gas with molar flow rate of 2118 kg mol h−1 was obtained 75 m3  h−1 of amine at 53 °C and 24 bar. This optimized condition is acceptable from economical, safe as well as feasible point of view.

  13. Virtual Tower

    International Nuclear Information System (INIS)

    Wayne, R.A.

    1997-01-01

    The primary responsibility of an intrusion detection system (IDS) operator is to monitor the system, assess alarms, and summon and coordinate the response team when a threat is acknowledged. The tools currently provided to the operator are somewhat limited: monitors must be switched, keystrokes must be entered to call up intrusion sensor data, and communication with the response force must be maintained. The Virtual tower is an operator interface assembled from low-cost commercial-off-the-shelf hardware and software; it enables large amounts of data to be displayed in a virtual manner that provides instant recognition for the operator and increases assessment accuracy in alarm annunciator and control systems. This is accomplished by correlating and fusing the data into a 360-degree visual representation that employs color, auxiliary attributes, video, and directional audio to prompt the operator. The Virtual Tower would be a valuable low-cost enhancement to existing systems

  14. Mycobacteria in Finnish cooling tower waters.

    Science.gov (United States)

    Torvinen, Eila; Suomalainen, Sini; Paulin, Lars; Kusnetsov, Jaana

    2014-04-01

    Evaporative cooling towers are water systems used in, e.g., industry and telecommunication to remove excess heat by evaporation of water. Temperatures of cooling waters are usually optimal for mesophilic microbial growth and cooling towers may liberate massive amounts of bacterial aerosols. Outbreaks of legionellosis associated with cooling towers have been known since the 1980's, but occurrences of other potentially pathogenic bacteria in cooling waters are mostly unknown. We examined the occurrence of mycobacteria, which are common bacteria in different water systems and may cause pulmonary and other soft tissue infections, in cooling waters containing different numbers of legionellae. Mycobacteria were isolated from all twelve cooling systems and from 92% of the 24 samples studied. Their numbers in the positive samples varied from 10 to 7.3 × 10(4) cfu/L. The isolated species included M. chelonae/abscessus, M. fortuitum, M. mucogenicum, M. peregrinum, M. intracellulare, M. lentiflavum, M. avium/nebraskense/scrofulaceum and many non-pathogenic species. The numbers of mycobacteria correlated negatively with the numbers of legionellae and the concentration of copper. The results show that cooling towers are suitable environments for potentially pathogenic mycobacteria. Further transmission of mycobacteria from the towers to the environment needs examination. © 2013 APMIS. Published by John Wiley & Sons Ltd.

  15. Cellular Phone Towers, Tower locations and attributes generated from FCC anntenna registration database. Tower data was cross referenced with county zoning special use permits., Published in 2008, 1:600 (1in=50ft) scale, Waupaca County Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Cellular Phone Towers dataset current as of 2008. Tower locations and attributes generated from FCC anntenna registration database. Tower data was cross referenced...

  16. Improving the efficiency of natural draft cooling towers

    International Nuclear Information System (INIS)

    Smrekar, J.; Oman, J.; Sirok, B.

    2006-01-01

    This study shows how the efficiency of a natural draft cooling tower can be improved by optimising the heat transfer along the cooling tower (CT) packing using a suitable water distribution across the plane area of the cooling tower. On the basis of cooling air measurements, it is possible to distribute the water in such a way that it approaches the optimal local water/air mass flow ratio and ensures the homogeneity of the heat transfer and a reduction of entropy generation, thus minimising the amount of exergy lost. The velocity and temperature fields of the air flow were measured with the aid of a remote control mobile robot unit that was developed to enable measurements at an arbitrary point above the spray zone over the entire plane area of the cooling tower. The topological structures of the moist air velocity profiles and the temperature profiles above the spray zone were used as input data for calculation of the local entropy generation in the tower. On the basis of the measured boundary conditions, a numerical analysis of the influence of the water distribution across the cooling tower's plane area on entropy generation and exergy destruction in the cooling tower was conducted

  17. Improving the efficiency of natural draft cooling towers

    Energy Technology Data Exchange (ETDEWEB)

    Smrekar, J. [Faculty of Mechanical Engineering, Askerceva 6, SI-1000 Ljubljana (Slovenia); Oman, J. [Faculty of Mechanical Engineering, Askerceva 6, SI-1000 Ljubljana (Slovenia)]. E-mail: janez.oman@fs.uni-lj.si; Sirok, B. [Faculty of Mechanical Engineering, Askerceva 6, SI-1000 Ljubljana (Slovenia)

    2006-06-15

    This study shows how the efficiency of a natural draft cooling tower can be improved by optimising the heat transfer along the cooling tower (CT) packing using a suitable water distribution across the plane area of the cooling tower. On the basis of cooling air measurements, it is possible to distribute the water in such a way that it approaches the optimal local water/air mass flow ratio and ensures the homogeneity of the heat transfer and a reduction of entropy generation, thus minimising the amount of exergy lost. The velocity and temperature fields of the air flow were measured with the aid of a remote control mobile robot unit that was developed to enable measurements at an arbitrary point above the spray zone over the entire plane area of the cooling tower. The topological structures of the moist air velocity profiles and the temperature profiles above the spray zone were used as input data for calculation of the local entropy generation in the tower. On the basis of the measured boundary conditions, a numerical analysis of the influence of the water distribution across the cooling tower's plane area on entropy generation and exergy destruction in the cooling tower was conducted.

  18. TacTower

    DEFF Research Database (Denmark)

    Rasmussen, Majken Kirkegaard; Jürgensen, Christine

    2009-01-01

    Learning from the multiplayer interaction in sports, we describe our project TacTower; a flexible system for professional elite handball players to train game perception and kinesthetic em- pathy. The design is founded in ideas of Collective Interaction and qualities that is inherent in sport...

  19. Modelling regional scale surface fluxes, meteorology and CO2 mixing ratios for the Cabauw tower in the Netherlands

    NARCIS (Netherlands)

    Tolk, L.F.; Peters, W.; Meesters, A.G.C.A.; Groenendijk, M.; Vermeulen, A.T.; Steeneveld, G.J.; Dolman, A.J.

    2009-01-01

    We simulated meteorology and atmospheric CO2 transport over the Netherlands with the mesoscale model RAMS-Leaf3 coupled to the biospheric CO2 flux model 5PM. The results were compared with meteorological and CO2 observations, with emphasis on the tall tower of Cabauw. An analysis of the coupled

  20. FLORIDA TOWER FOOTPRINT EXPERIMENTS

    Energy Technology Data Exchange (ETDEWEB)

    WATSON,T.B.; DIETZ, R.N.; WILKE, R.; HENDREY, G.; LEWIN, K.; NAGY, J.; LECLERC, M.

    2007-01-01

    The Florida Footprint experiments were a series of field programs in which perfluorocarbon tracers were released in different configurations centered on a flux tower to generate a data set that can be used to test transport and dispersion models. These models are used to determine the sources of the CO{sub 2} that cause the fluxes measured at eddy covariance towers. Experiments were conducted in a managed slash pine forest, 10 km northeast of Gainesville, Florida, in 2002, 2004, and 2006 and in atmospheric conditions that ranged from well mixed, to very stable, including the transition period between convective conditions at midday to stable conditions after sun set. There were a total of 15 experiments. The characteristics of the PFTs, details of sampling and analysis methods, quality control measures, and analytical statistics including confidence limits are presented. Details of the field programs including tracer release rates, tracer source configurations, and configuration of the samplers are discussed. The result of this experiment is a high quality, well documented tracer and meteorological data set that can be used to improve and validate canopy dispersion models.

  1. Adiabatic Rearrangement of Hollow PV Towers

    Directory of Open Access Journals (Sweden)

    Eric A Hendricks

    2010-10-01

    Full Text Available Diabatic heating from deep moist convection in the hurricane eyewall produces a towering annular structure of elevated potential vorticity (PV. This structure has been referred to as a hollow PV tower. The sign reversal of the radial gradient of PV satisfies the Charney-Stern necessary condition for combined barotropic-baroclinic instability. For thin enough annular structures, small perturbations grow exponentially, extract energy from the mean flow, and lead to hollow tower breakdown, with significant vortex structural and intensity change. The three-dimensional adiabatic rearrangements of two prototypical hurricane-like hollow PV towers (one thick and one thin are examined in an idealized framework. For both hollow towers, dynamic instability causes air parcels with high PV to be mixed into the eye preferentially at lower levels, where unstable PV wave growth rates are the largest. Little or no mixing is found to occur at upper levels. The mixing at lower and middle levels is most rapid for the breakdown of the thin hollow tower, consistent with previous barotropic results. For both hollow towers, this advective rearrangement of PV affects the tropical cyclone structure and intensity in a number of ways. First, the minimum central pressure and maximum azimuthal mean velocity simultaneously decrease, consistent with previous barotropic results. Secondly, isosurfaces of absolute angular momentum preferentially shift inward at low levels, implying an adiabatic mechanism by which hurricane eyewall tilt can form. Thirdly, a PV bridge, similar to that previously found in full-physics hurricane simulations, develops as a result of mixing at the isentropic levels where unstable PV waves grow most rapidly. Finally, the balanced mass field resulting from the PV rearrangement is warmer in the eye between 900 and 700 hPa. The location of this warming is consistent with observed warm anomalies in the eye, indicating that in certain instances the hurricane

  2. Adaptive Backstepping Control of Lightweight Tower Wind Turbine

    DEFF Research Database (Denmark)

    Galeazzi, Roberto; Borup, Kasper Trolle; Niemann, Hans Henrik

    2015-01-01

    the angular deflection of the tower with respect to the vertical axis in response to variations in wind speed. The controller is shown to guarantee asymptotic tracking of the reference trajectory. The performance of the control system is evaluated through deterministic and stochastic simulations including......This paper investigates the feasibility of operating a wind turbine with lightweight tower in the full load region exploiting an adaptive nonlinear controller that allows the turbine to dynamically lean against the wind while maintaining nominal power output. The use of lightweight structures...... for towers and foundations would greatly reduce the construction cost of the wind turbine, however extra features ought be included in the control system architecture to avoid tower collapse. An adaptive backstepping collective pitch controller is proposed for tower point tracking control, i.e. to modify...

  3. Analysis of Ideal Towers for Tall Wind Applications: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Dykes, Katherine L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Damiani, Rick R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Roberts, Joseph O [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Lantz, Eric J [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-02-27

    Innovation in wind turbine tower design is of significant interest for future development of wind power plants. First, wind turbine towers account for a large portion of overall capital expenditures for wind power projects. Second, for low wind-resource regions of the world, the use of low-cost tall-tower technology has the potential to open new markets for development. This study investigates the relative potential of various tower configurations in terms of mass and cost. For different market applications and hub heights, idealized tall towers are designed and compared. The results show that innovation in wind turbine controls makes reaching higher hub heights with current technology economically viable. At the same time, new technologies hold promise for reducing tower costs as these technologies mature and hub heights reach twice the current average.

  4. Ejection Tower Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The Ejection Tower Facility's mission is to test and evaluate new ejection seat technology being researched and developed for future defense forces. The captive and...

  5. Structure of natural draft cooling towers, 1

    International Nuclear Information System (INIS)

    Ishioka, Hitoshi; Sakamoto, Yukichi; Tsurusaki, Mamoru; Koshizawa, Koichi; Chiba, Toshio

    1976-01-01

    Thousands of natural draft cooling towers have been utilized, in Europe and America, as cooling systems of power plants or as countermeasures against thermal polution. Recently in Japan, demands for cooling tower systems have been increasing remarkably with the construction of large power plants and the legislation of environmental regulations. In view of the severe natural conditions in Japan such as strong wind and seismic loadings, etc., the establishment of the optimum design and construction method is essential for the building of safe and economical towers. In order to establish a comprehensive plan of a power plant cooling system of the appropriate structural type, the authors have made researches and experiments on design conditions, static and dynamic analyses, and comparative studies of various structural types such as reinforced concrete thin-shell structures, steel framed structures and composite shell segment structures, based on the investigation results of towers in Europe and America. These results are presented in three reports, the 1st of which concerns cooling tower shells as are hereinafter described. (auth.)

  6. The shape of natural draft cooling towers

    International Nuclear Information System (INIS)

    Grange, J.L.

    1992-07-01

    The shape of cooling towers is more often designed empirically. There, it is considered from a theoretical point of view. The analysis of dynamic of natural draft and of the air flow in a cooling tower shell is presented. It is shown, that although it is convergent, a tower works like a diffuser for pressure recovery. And it is turbulence that produces a transfer of kinetic energy and allows a good operation of the diffusor. The equations permit to define a shell profile which depends upon the operating conditions of the cooling tower. In the same way, a stability criteria for natural draft depending upon operating conditions is established. A heating model of one meter diameter has been built in a thermal similitude. The turbulence rate has been measured with a hot wire anemometer at the tower exit and visualizations have also been made. Natural draft stability has been studied by these means for four different shell shapes and a wide range of operating conditions. Experimental and theoretical results agree satisfactorily and experiments can be considered as a validation of theory

  7. The depletion of aqueous nitrous acid in packed towers

    International Nuclear Information System (INIS)

    Counce, R.M.; Crawford, D.B.

    1987-01-01

    The depletion of aqueous nitrous acid was studied at 298 0 K and at slightly greater than atmospheric pressure. Solutions containing nitrous and nitric acids were contacted with nitrogen in towers packed with 6- and 13-mm Intalox saddles. The results indicate the existence of two depletion mechanisms for the conditions studied - liquid-phase decomposition and direct desorption of nitrous acid. Models based on mass-transfer and chemical-kinetic information are presented to explain the experimental results. 24 refs., 8 figs., 3 tabs

  8. Building 'Tower' on the Partizans square in Užice (1961

    Directory of Open Access Journals (Sweden)

    Kuzović Duško

    2016-01-01

    Full Text Available The building 'Tower' at the Partisans Square in Užice was built from 1958 to 1961 designed by architect Milorad Pantović. It is located in the north zone on the street of Kralja Petra, in a continuous series of buildings that form the eastern side of the square room. Thanks to the topography of the terrain and the amount of public space, the tower dominates the square. Floors: Basement 1 + 2 basement + ground + mezzanine + 11 floors + attic. Tower at the Partisans Square represents the first multi-storey building which was built in Užice. The architectural value of the building represents a significant segment of the architectural heritage in Serbia and Yugoslavia.

  9. Occupational exposure to radiofrequency fields in antenna towers

    International Nuclear Information System (INIS)

    Alanko, T.; Hietanen, M.

    2007-01-01

    Exposure of workers to radiofrequency fields was assessed in two medium-sized antenna towers. Towers had transmitting antennas from different networks, e.g. mobile phone networks, radio and digital TV sub-stations and amateur radio. The levels of radiofrequency fields were measured close to the ladders of the towers. All measured values were below ICNIRP occupational reference levels. (authors)

  10. Simulation of CO2 concentrations at Tsukuba tall tower using WRF ...

    Indian Academy of Sciences (India)

    1School of Environmental Studies, Jadavpur University, Kolkata 700 032, India. ... nental or coastal sites is challenging because of coarse horizontal resolution of ... Here the regional Weather Research and Forecasting (WRF) model coupled .... at nine-towers regional networks during North ..... ond case, it falls to ≥0.57.

  11. 2D study of wind forces around multiple cooling towers using ...

    African Journals Online (AJOL)

    A comprehensive numerical study for the determination of wind pressure coefficients on multiple cooling towers by simulating turbulence using Reynolds Averaged Navier-Stokes Equations (RANS) models of Computational Fluid Dynamics techniques (CFD) such as, Standard k −ε , RNG k −ε , Realizable k −ε and Reynolds ...

  12. Cooling tower water ozonation at Southern University

    International Nuclear Information System (INIS)

    Chen, C.C.; Knecht, A.T.; Trahan, D.B.; Yaghi, H.M.; Jackson, G.H.; Coppenger, G.D.

    1990-01-01

    Cooling-tower water is a critical utility for many industries. In the past, inexpensive water coupled with moderate regulation of discharge water led to the neglect of the cooling tower as an energy resource. Now, with the increased cost of chemical treatment and tough EPA rules and regulations, this situation is rapidly changing. The operator of the DOE Y-12 Plant in Oak Ridge as well as many other industries are forced to develop an alternate method of water treatment. The cooling tower is one of the major elements in large energy systems. The savings accrued from a well engineered cooling tower can be a significant part of the overall energy conservation plan. During a short-term ozonation study between 1987-1988, the Y-12 Plant has been successful in eliminating the need for cooling tower treatment chemicals. However, the long-term impact was not available. Since April 1988, the ozone cooling water treatment study at the Y-12 Plant has been moved to the site at Southern University in Baton Rouge, Louisiana. The purpose of this continued study is to determine whether the use of ozonation on cooling towers is practical from an economic, technical and environmental standpoint. This paper discusses system design, operating parameter and performance testing of the ozonation system at Southern University

  13. The new Drop Tower catapult system

    Science.gov (United States)

    von Kampen, Peter; Kaczmarczik, Ulrich; Rath, Hans J.

    2006-07-01

    The Center of Applied Space Technology and Microgravity (ZARM) was founded in 1985 as an institute of the University Bremen, which focuses on research on gravitational and space-related phenomena. In 1988, the construction of the "Drop Tower" began. Since then, the eye-catching tower with a height of 146 m and its characteristic glass roof has become the emblem of the technology centre in Bremen. The Drop Tower Bremen provides a facility for experiments under conditions of weightlessness. Items are considered weightless, when they are in "free fall", i.e. moving without propulsion within the gravity field of the earth. The height of the tower limits the simple "free fall" experiment period to max. 4.74 s. With the inauguration of the catapult system in December 2004, the ZARM is entering a new dimension. This world novelty will meet scientists' demands of extending the experiment period up to 9.5 s. Since turning the first sod on May 3rd, 1988, the later installation of the catapult system has been taken into account by building the necessary chamber under the tower. The catapult system is located in a chamber 10 m below the base of the tower. This chamber is almost completely occupied by 12 huge pressure tanks. These tanks are placed around the elongation of the vacuum chamber of the drop tube. In its centre there is the pneumatic piston that accelerates the drop capsule by the pressure difference between the vacuum inside the drop tube and the pressure inside the tanks. The acceleration level is adjusted by means of a servo hydraulic breaking system controlling the piston velocity. After only a quarter of a second the drop capsule achieves its lift-off speed of 175 km/h. With this exact speed, the capsule will rise up to the top of the tower and afterwards fall down again into the deceleration unit which has been moved under the drop tube in the meantime. The scientific advantages of the doubled experiment time are obvious: during almost 10 s of high

  14. Cooling tower and environment

    International Nuclear Information System (INIS)

    Becker, J.; Ederhof, A.; Gosdowski, J.; Harms, A.; Ide, G.; Klotz, B.; Kowalczyk, R.; Necker, P.; Tesche, W.

    The influence of a cooling tower on the environment, or rather the influence of the environment on the cooling tower stands presently -along with the cooling water supply - in the middle of much discussion. The literature on these questions can hardly be overlooked by the experts concerned, especially not by the power station designers and operators. The document 'Cooling Tower and Environment' is intented to give a general idea of the important publications in this field, and to inform of the present state of technology. In this, the explanations on every section make it easier to get to know the specific subject area. In addition to older standard literature, this publication contains the best-known literature of recent years up to spring 1975, including some articles written in English. Further English literature has been collected by the ZAED (KFK) and is available at the VGB-Geschaefsstelle. Furthermore, The Bundesumweltamt compiles the literature on the subject of 'Environmental protection'. On top of that, further documentation centres are listed at the end of this text. (orig.) [de

  15. Frequency analysis of a tower-cable coupled system

    Energy Technology Data Exchange (ETDEWEB)

    Park, Moo Yeol [Young Sin Precision Engineering Ltd., Gyungju (Korea, Republic of); Kim, Seock Hyun; Park, In Su [Kangwon National University, Chuncheon (Korea, Republic of); Cui, Chengxun [Yanbian University, Yangji (China)

    2013-06-15

    This study considers the prediction of natural frequency to avoid resonance in a wind turbine tower- cable coupled system. An analytical model based on the Rayleigh-Ritz method is proposed to predict the resonance frequency of a wind turbine tower structure supported by four guy cables. To verify the validity of the analytical model, a small tower-cable model is manufactured and tested. The frequency and mode data of the tower model are obtained by modal testing and finite element analysis. The validity of the proposed method is verified through the comparison of the frequency analysis results. Finally, using a parametric study with the analytical model, we identified how the cable tension and cable angle affect the resonance frequency of the wind turbine tower structure. From the analysis results, the tension limit and optimal angle of the cable are identified.

  16. Mobile Tower Radiation Protection System

    Directory of Open Access Journals (Sweden)

    Jabbar Slman Hussein

    2017-12-01

    Full Text Available Clean environment is one of the most necessarily needs for Human life. So what about mobile effect and its towers pollution? It's effect on public health? Effect of huge groan of mobile networks. In counting of these dangers that will harm us from mobile towers in the far run, was the reasons for writing this research, came this study to look at the mobile towers and mobile effects possible health harm for the purpose of diagnosis of these effects and to suggest ways that can be used to avoid or minimize the risks.  Faraday Cage, is the solution suggested here, also there are many other solutions for this problem, a Faraday cage is a metallic enclosure that stops the entry or escape of an EM field. Also, two experiments are accomplished, first one showing the effect of Faraday cage on preventing the EMR from mobile cellphone, and the second  experiment gives the effect of Faraday cage on preventing the EMR from mobile tower EMR on human health listed in the research, that have been done by using conducting shell (grid design according the EM wavelength used by three company's mobile working in Iraq, the result show good isolations.

  17. Optimum design of a self-supported power transmission tower type 2M2 for 230 kW; Diseno optimo de una torre de transmision autosoportada tipo 2M2, para 230 kW

    Energy Technology Data Exchange (ETDEWEB)

    Espejel Valdez, Eduardo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico); Millan Monje, Alejandro; Honk Hernandez, Wenceslao [Comision Federal de Electricidad, (CFE), Mexico, D. F. (Mexico)

    1986-12-31

    A group of specialists from the Comision Federal de Electricidad (CFE) and of the Instituto de Investigaciones Electricas (IIE) analyzes the design of various types of power transmission towers in their application stage, in order to enhance them. In this article the structural characteristics of the self-supported tower type 2M2 for 230 kV of two circuits and of suspension, are presented. [Espanol] Un grupo de especialistas de la Comision Federal de Electricidad (CFE) y del Instituto de Investigaciones Electricas (IIE) analiza el diseno de diversos tipos de torres de transmision en su etapa de aplicacion, con el fin de mejorarlos. En este articulo se presentan las caracteristicas estructurales de la torre autosoportada tipo 2M2 para 230 kV, de dos circuitos y de suspension.

  18. Optimum design of a self-supported power transmission tower type 2M2 for 230 kW; Diseno optimo de una torre de transmision autosoportada tipo 2M2, para 230 kW

    Energy Technology Data Exchange (ETDEWEB)

    Espejel Valdez, Eduardo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico); Millan Monje, Alejandro; Honk Hernandez, Wenceslao [Comision Federal de Electricidad, (CFE), Mexico, D. F. (Mexico)

    1985-12-31

    A group of specialists from the Comision Federal de Electricidad (CFE) and of the Instituto de Investigaciones Electricas (IIE) analyzes the design of various types of power transmission towers in their application stage, in order to enhance them. In this article the structural characteristics of the self-supported tower type 2M2 for 230 kV of two circuits and of suspension, are presented. [Espanol] Un grupo de especialistas de la Comision Federal de Electricidad (CFE) y del Instituto de Investigaciones Electricas (IIE) analiza el diseno de diversos tipos de torres de transmision en su etapa de aplicacion, con el fin de mejorarlos. En este articulo se presentan las caracteristicas estructurales de la torre autosoportada tipo 2M2 para 230 kV, de dos circuitos y de suspension.

  19. Cooling towers

    International Nuclear Information System (INIS)

    Boernke, F.

    1975-01-01

    The need for the use of cooling systems in power plant engineering is dealt with from the point of view of a non-polluting form of energy production. The various cooling system concepts up to the modern natural-draught cooling towers are illustrated by examples. (TK/AK) [de

  20. A modular interpretation of various cubic towers

    DEFF Research Database (Denmark)

    Anbar Meidl, Nurdagül; Bassa, Alp; Beelen, Peter

    2017-01-01

    In this article we give a Drinfeld modular interpretation for various towers of function fields meeting Zink's bound.......In this article we give a Drinfeld modular interpretation for various towers of function fields meeting Zink's bound....

  1. Cellular Phone Towers, Cell towers developed for Appraiser's Department in 2003. Location was based upon parcel centroids, and corrected to orthophotography. Probably includes towers other than cell towers (uncertain). Not published., Published in 2003, 1:1200 (1in=100ft) scale, Sedgwick County Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Cellular Phone Towers dataset current as of 2003. Cell towers developed for Appraiser's Department in 2003. Location was based upon parcel centroids, and corrected...

  2. Distance protection of multiple-circuit shared tower transmission lines with different voltages

    DEFF Research Database (Denmark)

    Silva, Filipe Miguel Faria da; Bak, Claus Leth

    2017-01-01

    Multiple-circuit transmission lines combining different voltage levels in one tower present extra challenges when setting a protection philosophy, as faults between voltage levels are possible. This study presents a detailed theoretical analysis of such combined faults, including the development...... of a formula for estimating the magnitude of the short-circuit current. It is demonstrated that if the faulted phase from the higher voltage level leads the faulted phase from the lower voltage level, a distance relay at the higher voltage level sees the fault in the forward direction, whereas a distance relay...

  3. Pressure Drop Hysteresis of Hydrodynamic States in Packed Tower for Foaming Systems

    Directory of Open Access Journals (Sweden)

    Vijay Sodhi

    2011-11-01

    Full Text Available An experimental investigation was carried out to determine the effects of gas and liquid flow velocities and surface tension on the two-phase phase pressure drop a in a downflow trickle bed reactor. Water and non- Newtonian foaming solutions were employed as liquid phase. More than 240 experimental points for the trickle flow (GCF and foaming pulsing flow (PF/FPF regime were obtained for present study. Hydrodynamic characteristics involving two-phase pressure drop significantly influenced by gas and liquid flow rates. For 15 and 30 ppm air-aqueous surfactant solutions, two-phase pressure drop increases with higher liquid and gas flow velocities in trickle flow and foaming/pulsing flow regimes. With decrease in surface tension i.e. for 45 and 60 ppm air-aqueous surfactant systems, two-phase pressure drop increases very sharply during change in regime transition at significantly low liquid and gas velocities. Copyright © 2011 BCREC UNDIP. All rights reserved.(Received: 14th March 2011, Revised: 29th June 2011; Accepted: 4th July 2011[How to Cite: V. Sodhi, and R. Gupta. (2011. Pressure Drop Hysteresis of Hydrodynamic States in Packed Tower for Foaming Systems. Bulletin of Chemical Reaction Engineering & Catalysis, 6(2: 115-122. doi:10.9767/bcrec.6.2.828.115-122][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.6.2.828.115-122 || or local: http://ejournal.undip.ac.id/index.php/bcrec/article/view/828 ] | View in 

  4. Evaluation of dynamic response for monopole and hybrid wind mill tower

    Science.gov (United States)

    Shah, Hemal J.; Desai, Atul K.

    2017-07-01

    The wind mill towers are constructed using monopoles or lattice type tower. As the height of tower increases it gives more power but it becomes uneconomical, so in the present research work innovative wind mill tower such as combination of monopole and lattice tower is analyzed using FEM software. When the tall structures are constructed on soft soil it becomes dynamically sensitive so 3 types of soil such as hard, medium and soft soil is also modeled and the innovative tower is studied for different operating frequencies of wind turbine. From study it is concluded that the innovative tower will reduce resonance condition considering soil structure interaction.

  5. Validation of the Dynamic Wake Meander model with focus on tower loads

    Science.gov (United States)

    Larsen, T. J.; Larsen, G. C.; Pedersen, M. M.; Enevoldsen, K.; Madsen, H. A.

    2017-05-01

    This paper presents a comparison between measured and simulated tower loads for the Danish offshore wind farm Nysted 2. Previously, only limited full scale experimental data containing tower load measurements have been published, and in many cases the measurements include only a limited range of wind speeds. In general, tower loads in wake conditions are very challenging to predict correctly in simulations. The Nysted project offers an improved insight to this field as six wind turbines located in the Nysted II wind farm have been instrumented to measure tower top and tower bottom moments. All recorded structural data have been organized in a database, which in addition contains relevant wind turbine SCADA data as well as relevant meteorological data - e.g. wind speed and wind direction - from an offshore mast located in the immediate vicinity of the wind farm. The database contains data from a period extending over a time span of more than 3 years. Based on the recorded data basic mechanisms driving the increased loading experienced by wind turbines operating in offshore wind farm conditions have been identified, characterized and modeled. The modeling is based on the Dynamic Wake Meandering (DWM) approach in combination with the state-of-the-art aeroelastic model HAWC2, and has previously as well as in this study shown good agreement with the measurements. The conclusions from the study have several parts. In general the tower bending and yaw loads show a good agreement between measurements and simulations. However, there are situations that are still difficult to match. One is tower loads of single-wake operation near rated ambient wind speed for single wake situations for spacing’s around 7-8D. A specific target of the study was to investigate whether the largest tower fatigue loads are associated with a certain downstream distance. This has been identified in both simulations and measurements, though a rather flat optimum is seen in the measurements.

  6. Design and operation of hybrid cooling towers

    International Nuclear Information System (INIS)

    Alt, W.

    1987-01-01

    The first hybrid cooling tower at a coal-fired power station with a waste heat output of 550 MW has been in operation since the middle of 1985. Experience during the construction stage and the initial period of operation has confirmed the correctness of the design standards and of the design itself and, of course, also offers a wealth of knowledge to be observed on future construction projects. A second cooling tower of similar design is being erected at the present time. This cooling tower serves a power station unit with 2500 MW of waste heat output. The programme for this cooling tower offers the possibility for all the accumulated and evaluated experience to be of influence both on the design and also on the method of operation. This paper reports on the details. (orig.) [de

  7. Thermal performance of a transpired solar collector updraft tower

    International Nuclear Information System (INIS)

    Eryener, Dogan; Hollick, John; Kuscu, Hilmi

    2017-01-01

    Highlights: • Transpired solar collector updraft tower has been studied experimentally. • Transpired solar collector updraft tower efficiency ranges from 60 to 80%. • A comparison has been made with other SUT prototypes. • Three times higher efficiency compared to the glazed collectors of conventional solar towers. - Abstract: A novel solar updraft tower prototype, which consists of transpired solar collector, is studied, its function principle is described and its experimental thermal performance is presented for the first time. A test unit of transpired solar collector updraft tower was installed at the campus of Trakya University Engineering Faculty in Edirne-Turkey in 2014. Solar radiation, ambient temperature, collector cavity temperatures, and chimney velocities were monitored during summer and winter period. The results showed that transpired solar collector efficiency ranges from 60% to 80%. The maximum temperature rise in the collector area is found to be 16–18 °C on the typical sunny day. Compared to conventional solar tower glazed collectors, three times higher efficiency is obtained. With increased thermal efficiency, large solar collector areas for solar towers can be reduced in half or less.

  8. The Tower as a Metaphor and Concept

    DEFF Research Database (Denmark)

    Pihl, Ole Verner

    2007-01-01

     Abstract: The tower as an architectonic object is not only about scale, it is also about concept. In 1933, at the national showcase for the modernistic movement in Aalborg, Denmark the exhibition tower became a manifest and a landmark. The tower was inspired by the Russian constructivist Vladimir......: Gaming in a learning environment" that is an evaluation of the Sci-fi workshop seen from the outside.   Keywords: Tower, icon, experience design, interaction design, virtual and actual, past and future. ...

  9. Studies of column supported towers

    International Nuclear Information System (INIS)

    Chauvel, D.; Costaz, J.-L.

    1991-01-01

    As a result of a research and development programme into the civil engineering of cooling towers launched in 1978 by Electricite de France, very high cooling towers were built at Golfech and Chooz, in France, using column supports. This paper discusses the evolution of this new type of support from classical diagonal supports, presents some of the results of design calculations and survey measurements taken during construction of the shell and analyses the behaviour of the structure. (author)

  10. Plant Vogtle cooling tower studies

    International Nuclear Information System (INIS)

    O'Steen, L.

    2000-01-01

    Intensive ground-based field studies of plumes from two large, natural-draft cooling towers were conducted in support of the MTI modeling effort. Panchromatic imagery, IR imagery, meteorological data, internal tower temperatures and plant power data were collected during the field studies. These data were used to evaluate plume simulations, plume radioactive transfer calculations and plume volume estimation algorithms used for power estimation. Results from six field studies indicate that a 3-D atmospheric model at sufficient spatial resolution can effectively simulate a cooling tower plume if the plume is of sufficient size and the ambient meteorology is known and steady. Small plumes and gusty wind conditions degrade the agreement between the simulated and observed plumes. Thermal radiance calculations based on the simulated plumes produced maximum IR temperatures (near tower exit) which were in good agreement with measured IR temperatures for the larger plumes. For the smaller plumes, the calculated IR temperature was lower than the measured temperature by several degrees. Variations in maximum IR plume temperature with decreasing power (one reactor was undergoing a shutdown process), were clearly observed in the IR imagery and seen in the simulations. These temperature changes agreed with those calculated from an overall tower energy and momentum balance. Plume volume estimates based on camcorder images at three look angles were typically 20--30 percent larger than the plume volumes derived from the simulations, although one estimate was twice the simulated volume. Volume overestimation is expected and will have to be accounted for to some degree if plume volume is to be a useful diagnostic quantity in power estimation. Volume estimation with MTI imagery will require a large, stable plume and two looks in the visible bands (5m GSD) along with a solar shadow

  11. Mathematical model of drift deposition from a bifurcated cooling tower plume

    International Nuclear Information System (INIS)

    Chen, N.C.J.; Jung, L.

    1978-01-01

    Cooling tower drift deposition modeling has been extended by including centrifugal force induced through plume bifurcation in a crosswind as a mechanism for drift droplet removal from the plume. The model, in its current state of development, is capable of predicting the trajectory of a single droplet from the stage of strong interaction with the vortex field soon after droplet emission at the tower top through the stage of droplet evaporation in an unsaturated atmosphere after droplet breakaway from the plume. The computer program developed from the mathematical formulation has been used to explore the dependency of the droplet trajectory on droplet size, vortex strength, point of droplet emission, drag coefficient, droplet efflux speed, and ambient conditions. A specific application to drift from a mechanical-draft cooling tower (for a wind speed twice the efflux speed, a relative humidity of 70 per cent, and an initial droplet radius of 100 μm) showed the droplet to follow a helical trajectory within the plume, with breakaway occurring at 2.5 tower diameters downwind and ground impact of the droplet (reduced through evaporation to 55 μm radius) at 11 tower diameters

  12. Alkaline approach to treating cooling towers for control of Legionella pneumophila

    Energy Technology Data Exchange (ETDEWEB)

    States, S.J.; Conley, L.F.; Towner, S.G.; Wolford, R.S.; Stephenson, T.E.; McNamara, M.; Wadowsky, R.M.; Yee, R.B.

    1987-08-01

    Earlier field and laboratory studies have shown that Legionella species survive and multiply in the pH range 5.5 to 9.2. Additionally, the technical feasibility of operating cooling towers at elevated alkalinities and pH has previously been documented by published guidelines. The guidelines indicate that these conditions facilitate corrosion control and favor chlorine persistence which enhances the effectiveness of continuous chlorination in biofouling control. This information suggest that control of Legionella species in cooling towers can be accomplished by operating the towers under alkaline conditions. To test this possibility, we collected water samples over a period of months from a hospital cooling tower. The samples were analyzed for a variety of chemical parameters. Subsamples were pasteurized and inoculated with non-agar-passaged Legionella pneumophila which had been maintained in tap water. Correlation of subsequent Legionella growth with corresponding pH and alkalinity values revealed statistically significant inverse associations. These data support the hypothesis that operating cooling towers outside of the optimal conditions for Legionella growth (e.g., at elevated alkalinities and a pH greater than 9) may be a useful approach to controlling growth in this habitat.

  13. Engineering and economic evaluation of wet/dry cooling towers for water conservation

    International Nuclear Information System (INIS)

    Hu, M.C.

    1976-11-01

    The results are presented of a design and cost study for wet/dry tower systems used in conjunction with 1000 MWe nuclear power plants to reject waste heat while conserving water. Design and cost information for wet/dry tower systems are presented, and these cooling system alternatives are compared with wet and dry tower systems to determine whether the wet/dry tower concept is an economically viable alternative. The wet/dry cooling tower concept investigated is one which combines physically separated wet towers and dry towers into an operational unit. In designing the wet/dry tower, a dry cooling tower is sized to carry the plant heat load at low ambient temperatures, and a separate wet tower is added to augment the heat rejection of the dry tower at higher ambient temperatures. These wet/dry towers are designed to operate with a conventional low back pressure turbine commercially available today. The component wet and dry towers are state-of-the-art designs. From this study it was concluded that: wet/dry cooling systems can be designed to provide a significant economic advantage over dry cooling yet closely matching the dry tower's ability to conserve water, a wet/dry system which saves as much as 99 percent of the make-up water required by a wet tower can maintain that economic advantage, and therefore, for power plant sites where water is in short supply, wet/dry cooling is the economic choice over dry cooling

  14. [Genotypic variability and persistence of Legionella pulsed-field gel electrophoresis patterns in 16 cooling towers in Shanghai, China].

    Science.gov (United States)

    Chen, Ming-liang; Wang, Gang-yi; Chen, Min; Zhou, Hai-jian; Shao, Zhu-jun; Zhang, Xi; Wu, Fan

    2010-07-01

    To investigate the genotypic characteristics and persistence of Legionella pulsed-field gel electrophoresis (PFGE) patterns in 16 air-conditioner cooling towers in six different public sites of Shanghai. From May to October, continuous sampling was operated once per month in 2007. Legionella strains isolated from the 16 cooling towers were confirmed by serological and latex agglutination. PFGE was applied for the fingerprinting of the isolates, while the cluster results of PFGE were analyzed by BioNumerics software. 131 strains of Legionella were isolated, including L. pneumophila, L. bozemanae, L. micdadei and L. anisa. 52 distinguishable PFGE patterns were differentiated among the 16 cooling towers, with 37 patterns were owned by just one cooling tower, which was not shared with other cooling towers, while 15 patterns were shared by more than 2 cooling towers. All the cooling towers had ≥ 2 PFGE patterns, while in 13 cooling towers the same PFGE patterns were recovered during the six months. From June to October of 2007, 18 strains of Legionella belonging to the PFGE pattern of LPAs.SH0078 were isolated continuously from 6 cooling towers. This study demonstrated great genotypic diversity and complexity of Legionella in cooling towers. Persistence of the PFGE patterns was observed in 81.25% of the cooling towers. The PFGE pattern of LPAs. SH0078 was distributed widely, suggesting it might be the dominate strain in Shanghai.

  15. Effect of solar radiation on the performance of cross flow wet cooling tower in hot climate of Iran

    Science.gov (United States)

    Banooni, Salem; Chitsazan, Ali

    2016-11-01

    In some cities such as Ahvaz-Iran, the solar radiation is very high and the annual-mean-daily of the global solar radiation is about 17.33 MJ m2 d-1. Solar radiation as an external heat source seems to affect the thermal performance of the cooling towers. Usually, in modeling cooling tower, the effects of solar radiation are ignored. To investigate the effect of sunshade on the performance and modeling of the cooling tower, the experiments were conducted in two different states, cooling towers with and without sunshade. In this study, the Merkel's approach and finite difference technique are used to predict the thermal behavior of cross flow wet cooling tower without sunshade and the results are compared with the data obtained from the cooling towers with and without sunshade. Results showed that the sunshade is very efficient and it reduced the outlet water temperature, the approach and the water exergy of the cooling tower up to 1.2 °C, 15 and 1.1 %, respectively and increased the range and the efficiency of the cooling tower up to 29 and 37 %, respectively. Also, the sunshade decreased the error between the experimental data of the cooling tower with sunshade and the modeling results of the cooling tower without sunshade 1.85 % in average.

  16. Development from the seafloor to the sea surface of the cabled NEMO-SN1 observatory in the Western Ionian Sea

    Science.gov (United States)

    Sparnocchia, Stefania; Beranzoli, Laura; Borghini, Mireno; Durante, Sara; Favali, Paolo; Giovanetti, Gabriele; Italiano, Francesco; Marinaro, Giuditta; Meccia, Virna; Papaleo, Riccardo; Riccobene, Giorgio; Schroeder, Katrin

    2015-04-01

    implementation of new measurement capabilities at seafloor and along the water column with sensors for measurements of physical-chemical (pressure, temperature, salinity, dissolved oxygen, turbidity, pCO2, currents) and geophysical (magnetometer, seismometer and gravity meter) parameters. An imaging system for deep sea fauna will be deployed very soon at TSS. Furthermore, the data acquisition/elaboration system will be enhanced, and data will be shared in near real time through the Catania node of the high-speed telecommunication network for University and Scientific Research. An Open Access policy is adopted to favour the access of the international scientific community. According to the EMSO business plan and EC recommendations, the enhanced infrastructure will be open to scientists, companies and public actors on excellence research basis, for the development of innovative scientific and technological research products. The existing seafloor module is already offering this service under the TNA program of FixO3 EC Project (www.fixo3.eu). The ongoing development of NEMO-SN1 will strengthen its capabilities to monitor long-term variability of key physical, geophysical and biogeochemical parameters, with applications, for example, in studies on modifications of the properties of water masses and the marine circulation, changes in marine chemistry, with particular emphasis on the carbon system and its role in ocean acidification, evolving trends in global sea level, and to address geo-hazards issues, such as earthquake and tsunami risks, volcanic risk, instability and collapse of the slopes.

  17. 40 CFR 63.1329 - Process contact cooling towers provisions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Process contact cooling towers... Process contact cooling towers provisions. (a) The owner or operator of each new affected source that... end finisher process that utilizes a process contact cooling tower shall comply with paragraph (c) of...

  18. Optimization of steel monopod offshore-towers under probabilistic constraints

    NARCIS (Netherlands)

    Vrouwenvelder, A.C.W.M.

    2008-01-01

    In this work, economical design implementation of a circular steel monopod-offshore-tower, which is subjected to the extreme wave loading, is presented. The mass of the tower is considered as the objective function. The thickness and radius of the cross-section of the tower are adopted as design

  19. Load-Direction-Derived Support Structures for Wind Turbines: A Lattice Tower Concept and Preparations for Future Certifications: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Jonkman, Jason [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Damiani, Rick R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Struve, Achim [University of Applied Sciences Flensburg; Faber, Torsten [University of Applied Sciences Flensburg; Ummenhofer, Thomas [Karlsruhe Institute of Technology

    2017-11-07

    The call for more cost-effective and environmentally friendly tower concepts is motivated by tower costs [1] and tower CO2-emission contributions [2], which are high relative to the whole wind turbine system. The proposed rotatable tower concept with yaw bearing at the bottom instead of the top of the tower will provide beneficial economic and environmental impacts to the turbine system. This wind alignment capability indicates a load-direction-derived tower design. By combining this approach with a lattice concept, large material and cost savings for the tower can be achieved. This paper presents a way to analyze and verify the proposed design through aero-servo-elastic simulations, which make future certifications of rotatable tower concepts viable. For this reason, the state-of-the-art, open-source lattice-tower finite-element-method (FEM) module SubDyn [10], developed by the National Renewable Energy Laboratory, has been modified to account for arbitrary member cross-sections. Required changes in the beam element stiffness and mass matrix formulation took place according to an energy method [13]. All validated adaptions will be usable within the aero-servo-elastic simulation framework FAST and are also beneficial for other nonrotatable lattice structures.

  20. The Drop Tower Bremen -Experiment Operation

    Science.gov (United States)

    Könemann, Thorben; von Kampen, Peter; Rath, Hans J.

    The idea behind the drop tower facility of the Center of Applied Space Technology and Micro-gravity (ZARM) in Bremen is to provide an inimitable technical opportunity of a daily access to short-term weightlessness on earth. In this way ZARM`s european unique ground-based microgravity laboratory displays an excellent economic alternative for research in space-related conditions at low costs comparable to orbital platforms. Many national and international ex-perimentalists motivated by these prospects decide to benefit from the high-quality and easy accessible microgravity environment only provided by the Drop Tower Bremen. Corresponding experiments in reduced gravity could open new perspectives of investigation methods and give scientists an impressive potential for a future technology and multidisciplinary applications on different research fields like Fundamental Physics, Astrophysics, Fluid Dynamics, Combus-tion, Material Science, Chemistry and Biology. Generally, realizing microgravity experiments at ZARM`s drop tower facility meet new requirements of the experimental hardware and may lead to some technical constraints in the setups. In any case the ZARM Drop Tower Operation and Service Company (ZARM FAB mbH) maintaining the drop tower facility is prepared to as-sist experimentalists by offering own air-conditioned laboratories, clean rooms, workshops and consulting engineers, as well as scientific personal. Furthermore, ZARM`s on-site apartment can be used for accommodations during the experiment campaigns. In terms of approaching drop tower experimenting, consulting of experimentalists is mandatory to successfully accomplish the pursued drop or catapult capsule experiment. For this purpose there will be a lot of expertise and help given by ZARM FAB mbH in strong cooperation to-gether with the experimentalists. However, in comparison to standard laboratory setups the drop or catapult capsule setup seems to be completely different at first view. While defining a

  1. Prevalence of Legionella strains in cooling towers and legionellosis cases in New Zealand.

    Science.gov (United States)

    Lau, Robert; Maqsood, Saadia; Harte, David; Caughley, Brian; Deacon, Rob

    2013-01-01

    Over 3,900 water samples from 688 cooling towers were tested for Legionella in 2008 in New Zealand. Of 80 (2.05% isolation rate) Legionella isolates, 10 (12.5%) were L. pneumophila serogroup 1; 10 (12.5%) were L. anisa; nine (11.2%) were L. pneumophila serogroup 8; and one (1.2%) was L. longbeachae serogroup 2. Forty-one (51.2%) Legionella isolates were L. pneumophila serogroups. Over 3,990 water samples from 606 cooling towers were tested for Legionella in 2009 in New Zealand. Of 51 (1.28% isolation rate) Legionella isolates, 18 (35.3%) were L. pneumophila serogroup 1, and 39 (76.4%) were other L. pneumophila serogroups. L. pneumophila serogroups were significantly associated with legionellosis cases in 2008 and 2009. L. longbeachae serogroups were equally significantly associated with legionellosis cases. This significant association of L. longbeachae with legionellosis particularly of L. longbeachae serogroup 1 is unique in that part of the world. The authors' study also showed that the aqueous environment of the cooling tower is not a natural habitat for pathogenic L. longbeachae. Regular monitoring and maintenance of cooling towers have prevented outbreaks of legionellosis.

  2. Main photoautotrophic components of biofilms in natural draft cooling towers.

    Science.gov (United States)

    Hauer, Tomáš; Čapek, Petr; Böhmová, Petra

    2016-05-01

    While photoautotrophic organisms are an important component of biofilms that live in certain regions of natural draft cooling towers, little is known about these communities. We therefore examined 18 towers at nine sites to identify the general patterns of community assembly in three distinct tower parts, and we examined how community structures differ depending on geography. We also compared the newly acquired data with previously published data. The bottom sections of draft cooling towers are mainly settled by large filamentous algae, primarily Cladophora glomerata. The central portions of towers host a small amount of planktic algae biomass originating in the cooling water. The upper fourths of towers are colonized by biofilms primarily dominated by cyanobacteria, e.g., members of the genera Gloeocapsa and Scytonema. A total of 41 taxa of phototrophic microorganisms were identified. Species composition of the upper fourth of all towers was significantly affected by cardinal position. There was different species composition at positions facing north compared to positions facing south. West- and east-facing positions were transitory and highly similar to each other in terms of species composition. Biofilms contribute to the degradation of paint coatings inside towers.

  3. Round Earthen Towers in Zhangzhou

    Institute of Scientific and Technical Information of China (English)

    1992-01-01

    The round earthen towers inZhangzhou,Fujifan Province,have long been famous a-round the world.Built of rammedearth,each tower consists uf four tofive stories and Is nearly 100 metersin diameter and 17 to 18meters high.Scatteredaround the mountains,valleys and plains insouthwestern Fujian,thetowers look very muchlike round castles.SomeChinese and foreign ar-chitercts,historians andfolk-custom researcherscall them“flyng sau-cers”from outer spaceor“mushrooms”fromearth.They represent,indeed,a unique archi-tectural style in theworld.

  4. Dynamic analysis of cooling towers

    International Nuclear Information System (INIS)

    Bittnar, Z.

    1987-01-01

    Natural draught cooling towers are shell structures subjected to random vibrations due to wind turbulence and earthquake. The need of big power plant units has initiated the design of very large cooling towers. The random response of such structures may be analysed using a spectral approach and assuming a linear behaviour of the structure. As the modal superposition method is the most suitable procedure for this purpose it is necessary to determine the natural frequencies and mode shapes with adequate accuracy. (orig./GL)

  5. [Diversity of Legionella pneumophila in cooling towers: coculture kinetics and virulence studies].

    Science.gov (United States)

    Ragull, Sonia; García-Núñez, Marian; Pedro-Botet, María Luisa; Rey-Joly, Celestino; Sabria, Miquel

    2011-05-01

    Legionella pneumophila (L. pneumophila) was isolated from three cooling towers involved in three community outbreaks of Legionnaireś disease. Each cooling tower had two different chromosomal DNA subtypes. However, only one matched identically to the clinical strains. To try to understand why only one of the environmental strains caused clinical cases we investigated the intrinsic virulence of these strains. We selected six strains of L. pneumophila sg.1: two strains (A1 and B1) from cooling tower 1, two strains (A2 and B2) from tower 2 and two strains (A3 and B3) from tower 3. One of the two subtypes (A) exhibited the same chromosomal DNA subtype as the strains isolated from the patients in each outbreak and the other exhibited a different subtype. The replication within macrophages, the presence of lipopolysaccharide epitope recognized by MAb 3/1 and the growth kinetics in BCYE broth were investigated. Isolates were typed by pulsed field electrophoresis. The A strains did not have a higher virulence level, but were able to grow and survive better than strains B in BCYE broth. These results suggest that the strains better adapted to the environment will manage to displace the others and will be able to spread and infect humans. The adaptation to the environmental conditions could play an important role in the pathogenesis of the strains. Copyright © 2010 Elsevier España, S.L. All rights reserved.

  6. Cooling towers: a bibliography

    International Nuclear Information System (INIS)

    Whitson, M.O.

    1981-02-01

    This bibliography cites 300 selected references containing information on various aspects of large cooling tower technology, including design, construction, operation, performance, economics, and environmental effects. The towers considered include natural-draft and mechanical-draft types employing wet, dry, or combination wet-dry cooling. A few references deal with alternative cooling methods, principally ponds or spray canals. The citations were compiled for the DOE Energy Information Data Base (EDB) covering the period January to December 1980. The references are to reports from the Department of Energy and its contractors, reports from other government or private organizations, and journal articles, books, conference papers, and monographs from US originators

  7. Tall Tower Wind Energy Monitoring and Numerical Model Validation in Northern Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Koracin, D. [Desert Research Inst. (DRI), Las Vegas, NV (United States); Kaplan, M. [Desert Research Inst. (DRI), Las Vegas, NV (United States); Smith, C. [Desert Research Inst. (DRI), Las Vegas, NV (United States); McCurdy, G. [Desert Research Inst. (DRI), Las Vegas, NV (United States); Wolf, A. [Desert Research Inst. (DRI), Las Vegas, NV (United States); McCord, T. [Desert Research Inst. (DRI), Las Vegas, NV (United States); King, K. [Desert Research Inst. (DRI), Las Vegas, NV (United States); Belu, R. [Drexel Univ., Philadelphia, PA (United States); Horvath, K. [Croatian Meteorological and Hydrological Service, Zagreb (Croatia)

    2015-10-01

    The main objectives of this project were to conduct a tall-tower and sodar field campaign in complex terrain, investigate wind properties relevant to wind energy assessment, and evaluate high-resolution models with fixed and adaptive grid structures. Two 60-m towers at Virginia Peak ridges near Washoe Valley, Nevada, were instrumented with cup and vane anemometers as well as sonic anemometers, and an acoustic sounder (hereafter sodar) was installed near one of the towers. The towers were located 2,700 m apart with a vertical distance of 140 m elevation between their bases. Each tower had a downhill exposure of rolling complex terrain, with the nearby valley floor 3,200 m to the west and 800 m below the summit. Cup anemometers were installed at both towers at 20, 40, and 60 m, wind vanes at 20 and 60 m, and sonic anemometers at 20 and 60 m. The sodar measurements were nominally provided every 10 m in vertical distance from 40 to 200 m with the quality of the data generally decreasing with height. Surface air temperature, atmospheric pressure, and radiation measurements were conducted at 1.5 m AGL at both of the towers. Although the plan was to conduct a 1-year period of data collection, we extended the period (October 5, 2012 through February 24, 2014) to cover for possible data loss from instrument or communication problems. We also present a preliminary analysis of the towers and sodar data, including a detailed inventory of available and missing data as well as outliers. The analysis additionally includes calculation of the Weibull parameters, turbulence intensity, and initial computation of wind power density at various heights.

  8. Measurements at cooling tower plumes. Part 3. Three-dimensional measurements at cooling tower plumes

    International Nuclear Information System (INIS)

    Fortak, H.

    An extended field experiment is described in which cooling tower plumes were studied by means of three-dimensional in situ measurements. The goal was to obtain input data for numerical models of cooling tower plumes. Of special interest were data for testing or developing assumptions for sub-grid parametrizations. Utilizing modern systems for high-resolution aerology and small aircraft, four measuring campaigns were conducted: two campaigns (1974) at the cooling towers of the RWE power station Neurath and also two (1975) at the single cooling tower of the RWE power station Meppen. Because of the broad spectrum of weather situations it can be assumed that the results are representative with regard to the interrelationship between structure of cooling tower plume and large-scale meteorological situation. A large number of flights with a powered glider crossing the plumes on orthogonal tracks was performed. All flights showed that the plume could be identified up to large downwind distances by discontinuous jumps of temperature and vapor pressure. Therefore, a definite geometry of the plume could always be defined. In all cross sections a vertical circulation could be observed. At the boundary, which could be defined by the mentioned jumps of temperature and vapor pressure, a maximum of downward vertical motion could be observed in most cases. Entrainment along the boundary of a cross section seems to be very small, except at the lower part of the plume. There, the mass entrainment is maximum and is responsible for plume rise as well as for enlargement of the cross section. The visible part of the plume (cloud) was only a small fraction of the whole plume. High-resolution aerology is necessary in order to explain the structure and behavior of such plumes. This is especially the case in investigations regarding the dynamic break-through of temperature inversions. Such cases were observed frequently under various meteorological conditions and are described

  9. Heat Transfer Enhancement of the Air-Cooling Tower with Rotating Wind Deflectors under Crosswind Conditions

    Directory of Open Access Journals (Sweden)

    Xueping Du

    2018-04-01

    Full Text Available To investigate the effect of wind deflectors on air flow and heat transfer performance of an air-cooling tower under crosswind conditions, an experimental system based on a surface condenser aluminum exchanger-type indirect air-cooling tower is established at a 1:100 proportional reduction. A 3-D computational fluid dynamics simulation model is built to study the air flow and temperature fields. The air flow rate into the cooling tower and the heat transfer rate of the radiators are used to evaluate cooling performance. Rotating wind deflectors are adopted to reduce the influence of crosswind on the cooling tower performance. The effects of the rotating wind deflectors on the thermal-hydraulic characteristics of the air-cooling tower under different environmental crosswind speeds are studied. Results indicate that the wind direction in the tower reverses as the rotating speed of the wind deflectors increases. The thermal performance of an air-cooling tower under crosswind conditions can be improved by using rotating wind deflectors. The heat transfer rate of a cooling tower with eight wind deflectors begins to increase when the rotating speed exceeds 2 r/min.

  10. Deuterium- and 18O-content in the cooling water of power station cooling towers

    International Nuclear Information System (INIS)

    Heimbach, H.; Dongmann, G.

    1976-09-01

    The 0-18/0-16 and D/H isotope ratios of water from two different cooling towers were determined by mass spectrometry. The observed isotope fractionation corresponds to that known from natural evaporation or transpiration processes: cooling tower I: delta(D) = 46.8 per thousand, delta( 18 O) = 7.6 per thousand cooling tower II: delta(D) = 33.9 per thousand delta( 18 O) = 5.7 per thousand Evaluation of simple compartment models of a cooling tower and a distillation device suggests that there exists some isotope discrimination within the open trickling unit of a cooling tower analogous to that in a rectification column. In a real cooling tower, however, this effect is compensated largely by the recycling of the cooling water, resulting only in a small enrichment of the heavy isotopes. This can be understood as the result of three partial effects: 1) a fractionation in the vapor pressure equilibrium, 2) a kinetic effect due to diffusion of the water vapor into a turbulent atmosphere, and 3) an exchange effect which is proportional to relative humidity. This low enrichment of the heavy isotope excludes the technical use of cooling towers as isotope separation devices. (orig.) [de

  11. The Design of Akhmat Tower

    Directory of Open Access Journals (Sweden)

    Beardsley Sara

    2018-01-01

    Full Text Available Akhmat Tower is a 435m supertall building designed by Adrian Smith + Gordon Gill Architecture. It is currently under construction in the city of Grozny, in the Chechen Republic, in the North Caucasus region of Russia. The design of the tower was done during a collaborative process by a multi-disciplinary architectural and engineering team, based primarily in the United States and Russia. During this process, the designers considered many factors including, most primarily, the cultural and historical context, the structural requirements given the high seismicity of the region, and the client’s programmatic needs. The resulting crystalline-shaped tower is both an aesthetic statement and a performative architectural solution which will be a new landmark for Chechnya. “The Design of Akhmat Tower” describes in detail the design process including structural considerations, exterior wall design, building program, interior design, the tuned mass damper, and the use of building information modeling.

  12. Finding NEMO (novel electromaterial muscle oscillator): a polypyrrole powered robotic fish with real-time wireless speed and directional control

    International Nuclear Information System (INIS)

    McGovern, Scott; Alici, Gursel; Spinks, Geoffrey; Truong, Van-Tan

    2009-01-01

    This paper presents the development of an autonomously powered and controlled robotic fish that incorporates an active flexural joint tail fin, activated through conducting polymer actuators based on polypyrrole (PPy). The novel electromaterial muscle oscillator (NEMO) tail fin assembly on the fish could be controlled wirelessly in real time by varying the frequency and duty cycle of the voltage signal supplied to the PPy bending-type actuators. Directional control was achieved by altering the duty cycle of the voltage input to the NEMO tail fin, which shifted the axis of oscillation and enabled turning of the robotic fish. At low speeds, the robotic fish had a turning circle as small as 15 cm (or 1.1 body lengths) in radius. The highest speed of the fish robot was estimated to be approximately 33 mm s −1 (or 0.25 body lengths s −1 ) and was achieved with a flapping frequency of 0.6–0.8 Hz which also corresponded with the most hydrodynamically efficient mode for tail fin operation. This speed is approximately ten times faster than those for any previously reported artificial muscle based device that also offers real-time speed and directional control. This study contributes to previously published studies on bio-inspired functional devices, demonstrating that electroactive polymer actuators can be real alternatives to conventional means of actuation such as electric motors

  13. Finding NEMO (novel electromaterial muscle oscillator): a polypyrrole powered robotic fish with real-time wireless speed and directional control

    Science.gov (United States)

    McGovern, Scott; Alici, Gursel; Truong, Van-Tan; Spinks, Geoffrey

    2009-09-01

    This paper presents the development of an autonomously powered and controlled robotic fish that incorporates an active flexural joint tail fin, activated through conducting polymer actuators based on polypyrrole (PPy). The novel electromaterial muscle oscillator (NEMO) tail fin assembly on the fish could be controlled wirelessly in real time by varying the frequency and duty cycle of the voltage signal supplied to the PPy bending-type actuators. Directional control was achieved by altering the duty cycle of the voltage input to the NEMO tail fin, which shifted the axis of oscillation and enabled turning of the robotic fish. At low speeds, the robotic fish had a turning circle as small as 15 cm (or 1.1 body lengths) in radius. The highest speed of the fish robot was estimated to be approximately 33 mm s-1 (or 0.25 body lengths s-1) and was achieved with a flapping frequency of 0.6-0.8 Hz which also corresponded with the most hydrodynamically efficient mode for tail fin operation. This speed is approximately ten times faster than those for any previously reported artificial muscle based device that also offers real-time speed and directional control. This study contributes to previously published studies on bio-inspired functional devices, demonstrating that electroactive polymer actuators can be real alternatives to conventional means of actuation such as electric motors.

  14. Tower Mesonetwork Climatology and Interactive Display Tool

    Science.gov (United States)

    Case, Jonathan L.; Bauman, William H., III

    2004-01-01

    Forecasters at the 45th Weather Squadron and Spaceflight Meteorology Group use data from the tower network over the Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) to evaluate Launch Commit Criteria, and issue and verify forecasts for ground operations. Systematic biases in these parameters could adversely affect an analysis, forecast, or verification. Also, substantial geographical variations in temperature and wind speed can occur under specific wind directions. To address these concerns, the Applied Meteorology Unit (AMU) developed a climatology of temperatures and winds from the tower network, and identified the geographical variation and significant tower biases. The mesoclimate is largely driven by the complex land-water interfaces across KSC/CCAFS. Towers with close proximity to water typically had much warmer nocturnal temperatures and higher wind speeds throughout the year. The strongest nocturnal wind speeds occurred from October to March whereas the strongest mean daytime wind speeds occurred from February to May. These results of this project can be viewed by forecasters through an interactive graphical user interface developed by the AMU. The web-based interface includes graphical and map displays of mean, standard deviation, bias, and data availability for any combination of towers, variables, months, hours, and wind directions.

  15. Study on the blasting demolition of steel construction. Part 2. Demolition work of steel tower; Tekkotsu kozobutsu no bakuha kaitai ni kansuru kenkyu. 2. Koro yagura happa kaitai koji

    Energy Technology Data Exchange (ETDEWEB)

    Ogata, Y.; Wada, Y.; Katsuyama, K. [National Institute for Resources and Environment, Tsukuba (Japan); Nishida, T.; Hoshino, M.; Nagano, M. [Kacoh Co. Ltd., Tokyo (Japan)

    1997-06-30

    This paper describes the blasting demolition of steel tower of iron works. The steel tower had four columns, and its dimension was 17 mtimes17 m in cross section and 77.6 m height. The total weight was about 1,724 t. The 18.4 kg V-type linear shaped charge was fixed around columns with box weld structures, and initiated using 16 seismograph electric detonators. Vibration and noise were measured during blasting and collapse of the tower. In the both case, the vibration levels were between 67 and 71 dB, which were low and under 75 dB, the standard level during specific construction works of the regulation act of vibration. The noise level was 120 dB(A) at the point 200 m away from the blasting source, which was over 85 dB(A), the standard level. The collapse process of steel tower was simulated using discontinuous deformation analysis. The results agreed well with those from the actual collapse. The steel tower landed about 6 seconds after the initiation, and it took about 15 seconds to complete the collapse. Before the demolition, the 6 t parts of forefeet of two columns in the collapse direction were cut and removed by blasting. Thus, the collapse was controlled in the given direction. 5 refs., 13 figs., 2 tabs.

  16. Counter flow induced draft cooling tower option for supercritical carbon dioxide Brayton cycle

    Energy Technology Data Exchange (ETDEWEB)

    Pidaparti, Sandeep R., E-mail: sandeep.pidaparti@gmail.com [Georgia Institute of Technology, George W. Woodruff School of Mechanical Engineering, Atlanta, GA 30332 (United States); Moisseytsev, Anton; Sienicki, James J. [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Ranjan, Devesh, E-mail: devesh.ranjan@me.gatech.edu [Georgia Institute of Technology, George W. Woodruff School of Mechanical Engineering, Atlanta, GA 30332 (United States)

    2015-12-15

    Highlights: • A code was developed to investigate the various aspects of using cooling tower for S-CO{sub 2} Brayton cycles. • Cooling tower option to reject heat is quantitatively compared to the direct water cooling and dry air cooling options. • Optimum water conditions resulting in minimal plant capital cost per unit power consumption are calculated. - Abstract: A simplified qualitative analysis was performed to investigate the possibility of using counter flow induced draft cooling tower option to reject heat from the supercritical carbon dioxide Brayton cycle for advanced fast reactor (AFR)-100 and advanced burner reactor (ABR)-1000 plants. A code was developed to estimate the tower dimensions, power and water consumption, and to perform economic analysis. The code developed was verified against a vendor provided quotation and is used to understand the effect of ambient air and water conditions on the design of cooling tower. The calculations indicated that there exists optimum water conditions for given ambient air conditions which will result in minimum power consumption, thereby increasing the cycle efficiency. A cost-based optimization technique is used to estimate the optimum water conditions which will improve the overall plant economics. A comparison of different cooling options for the S-CO{sub 2} cycle indicated that the cooling tower option is a much more practical and economical option compared to the dry air cooling or direct water cooling options.

  17. Performance of water distribution systems in a pilot cooling tower

    International Nuclear Information System (INIS)

    Tognotti, L.; Giacomelli, A.; Zanelli, S.; Bellagamba, B.; Lotti, G.; Mattachini, F.

    1990-01-01

    An experimental study has been carried out on the water distribution system of a Pilot cooling tower of 160 m 3 /hr The performances of different industrial water distributors have been evaluated by changing the operative conditions of the pilot tower. In particular, the efficiency and the uniformity of the water distribution have been investigated and compared with the results obtained in a small-scale loop, in which the single nozzles were tested. Measurements in both systems, pilot tower and small scale loop, included the geometric characteristics of the jet umbrella by ensemble photography, the wetted zone by measuring the specific flowrate, the drop-size distribution and liquid concentration by high-speed photography. The results show that correlations exist between the nozzle behaviour in single and pilot tower configuration. The uniformity of water distribution in the pilot tower is strongly related to the nozzle installation pattern and to the operative conditions. Coalescence plays an important role on the drop size distribution in the pilot-tower. Comments upon the influence of these parameters on tower behaviour are also included

  18. Constraining CO2 tower measurements in an inhomogeneous area with anthropogenic emissions using a combination of car-mounted instrument campaigns, aircraft profiles, transport modeling and neural networks

    Science.gov (United States)

    Schmidt, A.; Rella, C.; Conley, S. A.; Goeckede, M.; Law, B. E.

    2013-12-01

    The NOAA CO2 observation network in Oregon has been enhanced by 3 new towers in 2012. The tallest tower in the network (270 m), located in Silverton in the Willamette Valley is affected by anthropogenic emissions from Oregon's busiest traffic routes and urban centers. In summer 2012, we conducted a measurement campaign using a car-mounted PICARRO CRDS CO2/CO analyzer. Over 3 days, the instrument was driven over 1000 miles throughout the northwestern portion of Oregon measuring the CO/ CO2 ratios on main highways, back roads in forests, agricultural sites, and Oregon's biggest urban centers. By geospatial analyses we obtained ratios of CO/ CO2 over distinct land cover types divided into 10 classes represented in the study area. Using the coupled WRF-STILT transport model we calculated the footprints of nearby CO/ CO2 observation towers for the corresponding days of mobile road measurements. Spatiotemporally assigned source areas in combination with the land use classification were then used to calculate specific ratios of CO (anthropogenic origins) and CO2 to separate the anthropogenic portion of CO2 from the mixing ratio time series measured at the tower in Silverton. The WRF modeled boundary layer heights used in out study showed some differences compared to the boundary layer heights derived from profile data of wind, temperature, and humidity measured with an airplane in August, September, and November 2012, repeatedly over 5 tower locations. A Bayesian Regularized Artificial Neural Network (BRANN) was used to correct the boundary layer height calculated with WRF with a temporal resolution of 20 minutes and a horizontal resolution of 4 km. For that purpose the BRANN was trained using height profile data from the flight campaigns and spatiotemporally corresponding meteorological data from WRF. Our analyses provide information needed to run inverse modeling of CO2 exchange in an area that is affected by sources that cannot easily be considered by biospheric models

  19. Piers cooling towers. From first idess to realizations

    International Nuclear Information System (INIS)

    Bozetto, P.; Tzincoca, A.

    1988-01-01

    After a first part consecrated at the historical aspect of vertical piers cooling towers the second part indicates the experience pulled of the Chooz and Golfech cooling towers conception and realization [fr

  20. On the prospects for dry cooling tower building in FRG

    International Nuclear Information System (INIS)

    Dzhurinskij, M.B.; Zlotin, A.A.

    1982-01-01

    Advantages and disadvantages of dry cooling towers for NPPs are considered. Construction of a number of cooling towers in FRY are described. The advisability of building cooling towers of a combined type - with wet aud dry sections is noted

  1. A study of the life expectancy of cooling towers

    International Nuclear Information System (INIS)

    Bolvin, M.; Chauvel, D.

    1993-01-01

    The paper describes the following different tasks of the study whose aim was to extend the life time of cooling towers for French Nuclear Power plants to 40 years. The aging factors specific to cooling towers were measured and analysed with regard to the external surface, the internal surface and inside the concrete. The safety coefficient for buckling was calculated and then the stress analysis of the materials (concrete and steel) was done. A special computer program written for cooling towers was used with a model including the soil stiffness and the supports of the tower. (author)

  2. Method for heavy-water production by H2S--H2O chemical exchange process

    International Nuclear Information System (INIS)

    Strathdee, G.G.

    1978-01-01

    The invention discloses a heavy water production stage in a bithermal H 2 S gas H 2 O liquid exchange plant wherein the cold tower is operated under temperature and pressure conditions such that H 2 S in the liquid phase is formed and is maintained in the separation units (sieve trays or plates) of the cold tower. It has been found that the presence of liquid H 2 S acts as an efficient anti-foaming agent

  3. Jules Verne's Captain Nemo and French Revolutionary Gustave Flourens:A Hidden Character Model?

    Directory of Open Access Journals (Sweden)

    Leonidas Kallivretakis

    2005-01-01

    Full Text Available This article treats the recent assumption made by Vernian specialist William Butcher that Jules Verne's most famous character, Captain Nemo, is based on the French revolutionary intellectual Gustave Flourens (1838-1871, son of the eminent physiologist J. P. M. Flourens. Gustave Flourens fought in the Cretan insurrection of 1866-1868, later participated in the republican opposition against Napoleon III's imperial regime, eventually became a friend of Karl Marx and was finally killed as a general of the Paris Commune. By comparing step-by-step Verne's inspiration and writing procedures with Flourens' unfolding activities and fame, it is concluded that there is little basis for such an assumption. The article includes also a brief account of the Cretan question in the nineteenth century and of the deep discord between Marx's and Flourens' respective analyses of the Eastern Question.

  4. Noise from cooling towers of power parks

    International Nuclear Information System (INIS)

    Zakaria, J.; Moore, F.K.

    1975-01-01

    A study is presented of the noise pollution problem for large power parks proposed for the future. Such parks might have an area of about 75 sq. miles, and a generating capacity up to 48000 MW. A comparative analysis has been done for natural and mechanical-draft wet towers as the major sources of acoustic power. Noise radiation from single isolated towers as well as from a dispersed array of towers has been considered for both types of cooling systems. Major noise attenuation effects considered are due to the atmospheric absorption and A-weighting. Conditions of 60F and 70 percent relative humidity in a still atmosphere have been assumed

  5. Hybrid cooling tower Neckarwestheim 2 cooling function, emission, plume dispersion

    International Nuclear Information System (INIS)

    Braeuning, G.; Ernst, G.; Maeule, R.; Necker, P.

    1990-01-01

    The fan-assisted hybrid cooling tower of the 1300 MW power plant Gemeinschafts-Kernkraftwerk Neckarwestheim 2 was designed and constructed based on results from theoretical and experimental studies and experiences from a smaller prototype. The wet part acts in counterflow. The dry part is arranged above the wet part. Each part contains 44 fans. Special attention was payed to the ducts which mix the dry into the wet plume. The cooling function and state, mass flow and contents of the emission were measured. The dispersion of the plume in the atmosphere was observed. The central results are presented in this paper. The cooling function corresponds to the predictions. The content of drifted cooling water in the plume is extremely low. The high velocity of the plume in the exit causes an undisturbed flow into the atmosphere. The hybrid operation reduces visible plumes strongly, especially in warmer and drier ambient air

  6. Cell-Phone Tower Power System Prototype Testing for Verizon Wireless |

    Science.gov (United States)

    Advanced Manufacturing Research | NREL Cell-Phone Tower Power System Prototype Testing for Verizon Wireless Cell-Phone Tower Power System Prototype Testing for Verizon Wireless For Verizon Wireless , NREL tested a new cell-phone tower power system prototype based on DC interconnection and photovoltaics

  7. TacTower

    DEFF Research Database (Denmark)

    Rasmussen, Majken Kirkegaard; Jürgensen, Christine

    2009-01-01

    Learning from the multiplayer interaction in sports, we describe our project TacTower; a flexible system for professional elite handball players to train game perception and kinesthetic em- pathy. The design is founded in ideas of Collective Interaction and qualities that is inherent in sport...... and is based on consid- erations about paralanguage, kinesthetic emphatic interaction, physical positioning of players and collaborative interaction....

  8. The Damaging Effects of Earthquake Excitation on Concrete Cooling Towers

    International Nuclear Information System (INIS)

    Abedi-Nik, Farhad; Sabouri-Ghomi, Saeid

    2008-01-01

    Reinforced concrete cooling towers of hyperbolic shell configuration find widespread application in utilities engaged in the production of electric power. In design of critical civil infrastructure of this type, it is imperative to consider all the possible loading conditions that the cooling tower may experience, an important loading condition in many countries is that of the earthquake excitation, whose influence on the integrity and stability of cooling towers is profound. Previous researches have shown that the columns supporting a cooling tower are sensitive to earthquake forces, as they are heavily loaded elements that do not possess high ductility, and understanding the behavior of columns under earthquake excitation is vital in structural design because they provide the load path for the self weight of the tower shell. This paper presents the results of a finite element investigation of a representative 'dry' cooling tower, using realistic horizontal and vertical acceleration data obtained from the recent and widely-reported Tabas, Naghan and Bam earthquakes in Iran. The results of both linear and nonlinear analyses are reported in the paper, the locations of plastic hinges within the supporting columns are identified and the ramifications of the plastic hinges on the stability of the cooling tower are assessed. It is concluded that for the (typical) cooling tower configuration analyzed, the columns that are instrumental in providing a load path are influenced greatly by earthquake loading, and for the earthquake data used in this study the representative cooling tower would be rendered unstable and would collapse under the earthquake forces considered

  9. The Transmission Channel Tower Identification and Landslide Disaster Monitoring Based on Insar

    Science.gov (United States)

    Li, G.; Tan, Q.; Xie, C.; Fei, X.; Ma, X.; Zhao, B.; Ou, W.; Yang, Z.; Wang, J.; Fang, H.

    2018-04-01

    The transmission distance of transmission lines is long, the line affected by the diversity of climate and topography of the corridors of transmission lines, differences in regional geological structure conditions, variability of rock and soil types, and the complexity of groundwater. Under the influence of extreme weather conditions (ice-covered, strong wind, etc.) and sudden geological disasters (such as mudslides, flash floods, earthquakes, etc.), catastrophic damage and basic deformation problems of the tower foundations are prone, and even tower collapse accidents occur in severe cases, which affect the safe operation of transmission lines. Monitoring the deformation of power transmission towers and surrounding grounds, it is critical to ensuring the normal operation of transmission lines by assessing and controlling potential risks in advance. In this paper, using ALOS-2 PALSAR radar satellite data, differential interferometry was used to monitor surface deformation near the Sichuan Jinsu line transmission channel. The analysis found that a significant landslide hazard was found near the transmission channel tower in Yibin-Zhaotong section of Jinsu, Sichuan Province, the cumulative deformation reaches 9cm. The results of this paper can provide new monitoring means for safety monitoring of transmission towers.

  10. An alkaline approach to treating cooling towers for control of Legionella pneumophila.

    Science.gov (United States)

    States, S J; Conley, L F; Towner, S G; Wolford, R S; Stephenson, T E; McNamara, A M; Wadowsky, R M; Yee, R B

    1987-08-01

    Earlier field and laboratory studies have shown that Legionella species survive and multiply in the pH range 5.5 to 9.2. Additionally, the technical feasibility of operating cooling towers at elevated alkalinities and pH has previously been documented by published guidelines. The guidelines indicate that these conditions facilitate corrosion control and favor chlorine persistence which enhances the effectiveness of continuous chlorination in biofouling control. This information suggests that control of Legionella species in cooling towers can be accomplished by operating the towers under alkaline conditions. To test this possibility, we collected water samples over a period of months from a hospital cooling tower. The samples were analyzed for a variety of chemical parameters. Subsamples were pasteurized and inoculated with non-agar-passaged Legionella pneumophila which had been maintained in tap water. Correlation of subsequent Legionella growth with corresponding pH and alkalinity values revealed statistically significant inverse associations. These data support the hypothesis that operating cooling towers outside of the optimal conditions for Legionella growth (e.g., at elevated alkalinities and a pH greater than 9) may be a useful approach to controlling growth in this habitat.

  11. Removing traffic emissions from CO2 time series measured at a tall tower using mobile measurements and transport modeling

    Science.gov (United States)

    Schmidt, Andres; Rella, Chris W.; Göckede, Mathias; Hanson, Chad; Yang, Zhenlin; Law, Beverly E.

    2014-11-01

    In recent years, measurements of atmospheric carbon dioxide with high precision and accuracy have become increasingly important for climate change research, in particular to inform terrestrial biosphere models. Anthropogenic carbon dioxide emissions from fossil fuel burning have long been recognized to contribute a significant portion of the carbon dioxide in the atmosphere. Here, we present an approach to remove the traffic related carbon dioxide emissions from mole fractions measured at a tall tower by using the corresponding carbon monoxide measurements in combination with footprint analyses and transport modeling. This technique improves the suitability of the CO2 data to be used in inverse modeling approaches of atmosphere-biosphere exchange that do not account for non-biotic portions of CO2. In our study region in Oregon, road traffic emissions are the biggest source of anthropogenic carbon dioxide and carbon monoxide. A three-day mobile campaign covering 1700 km of roads in northwestern Oregon was performed during summer of 2012 using a laser-based Cavity Ring-Down Spectrometer. The mobile measurements incorporated different roads including main highways, urban streets, and back-roads, largely within the typical footprint of a tall CO/CO2 observation tower in Oregon's Willamette Valley. For the first time, traffic related CO:CO2 emission ratios were measured directly at the sources during an on-road campaign under a variety of different driving conditions. An average emission ratio of 7.43 (±1.80) ppb CO per ppm CO2 was obtained for the study region and applied to separate the traffic related portion of CO2 from the mole fraction time series. The road traffic related portion of the CO2 mole fractions measured at the tower site reached maximum values ranging from 9.8 to 12 ppm, depending on the height above the surface, during summer 2012.

  12. Full scale experimental study of a small natural draft dry cooling tower for concentrating solar thermal power plant

    International Nuclear Information System (INIS)

    Li, Xiaoxiao; Duniam, Sam; Gurgenci, Hal; Guan, Zhiqiang; Veeraragavan, Anand

    2017-01-01

    Highlights: • A 20 m high natural draft dry cooling tower is designed and tested. • The cooling tower model is refined and validated with the experimental data. • The performance of the cooling tower utilized in a CST power plant is investigated. • Ambient temperature effect on Rankine cycle and Brayton cycle is discussed. - Abstract: Concentrating solar thermal power system can provide low carbon, renewable energy resources in countries or regions with strong solar irradiation. For this kind of power plant which is likely to be located in the arid area, natural draft dry cooling tower is a promising choice. To develop the experimental studies on small cooling tower, a 20 m high natural draft dry cooling tower with fully instrumented measurement system was established by the Queensland Geothermal Energy Centre of Excellence. The performance of this cooling tower was measured with the constant heat input of 600 kW and 840 kW and with ambient temperature ranging from 20 °C to 32 °C. The cooling tower numerical model was refined and validated with the experimental data. The model of 1 MW concentrating solar thermal supercritical CO_2 power cycle was developed and integrated with the cooling tower model. The influences of changing ambient temperature and the performance of the cooling tower on efficiency of the power system were simulated. The differences of the mechanism of the ambient temperature effect on Rankine cycle and supercritical CO_2 Brayton cycle were analysed and discussed.

  13. Legionella confirmation in cooling tower water

    Science.gov (United States)

    Farhat, Maha; Shaheed, Raja A.; Al-Ali, Haidar H.; Al-Ghamdi, Abdullah S.; Al-Hamaqi, Ghadeer M.; Maan, Hawraa S.; Al-Mahfoodh, Zainab A.; Al-Seba, Hussain Z.

    2018-01-01

    Objectives: To investigate the presence of Legionella spp in cooling tower water. Legionella proliferation in cooling tower water has serious public health implications as it can be transmitted to humans via aerosols and cause Legionnaires’ disease. Methods: Samples of cooling tower water were collected from King Fahd Hospital of the University (KFHU) (Imam Abdulrahman Bin Faisal University, 2015/2016). The water samples were analyzed by a standard Legionella culture method, real-time polymerase chain reaction (RT-PCR), and 16S rRNA next-generation sequencing. In addition, the bacterial community composition was evaluated. Results: All samples were negative by conventional Legionella culture. In contrast, all water samples yielded positive results by real-time PCR (105 to 106 GU/L). The results of 16S rRNA next generation sequencing showed high similarity and reproducibility among the water samples. The majority of sequences were Alpha-, Beta-, and Gamma-proteobacteria, and Legionella was the predominant genus. The hydrogen-oxidizing gram-negative bacterium Hydrogenophaga was present at high abundance, indicating high metabolic activity. Sphingopyxis, which is known for its resistance to antimicrobials and as a pioneer in biofilm formation, was also detected. Conclusion: Our findings indicate that monitoring of Legionella in cooling tower water would be enhanced by use of both conventional culturing and molecular methods. PMID:29436561

  14. Tower-Top Antenna Array Calibration Scheme for Next Generation Networks

    Directory of Open Access Journals (Sweden)

    McCormack Justine

    2007-01-01

    Full Text Available Recently, there has been increased interest in moving the RF electronics in basestations from the bottom of the tower to the top, yielding improved power efficiencies and reductions in infrastructural costs. Tower-top systems have faced resistance in the past due to such issues as increased weight, size, and poor potential reliability. However, modern advances in reducing the size and complexity of RF subsystems have made the tower-top model more viable. Tower-top relocation, however, faces many significant engineering challenges. Two such challenges are the calibration of the tower-top array and ensuring adequate reliability. We present a tower-top smart antenna calibration scheme designed for high-reliability tower-top operation. Our calibration scheme is based upon an array of coupled reference elements which sense the array's output. We outline the theoretical limits of the accuracy of this calibration, using simple feedback-based calibration algorithms, and present their predicted performance based on initial prototyping of a precision coupler circuit for a array. As the basis for future study a more sophisticated algorithm for array calibration is also presented whose performance improves with array size.

  15. An improved model for the analysis of evaporative counterflow cooling towers

    International Nuclear Information System (INIS)

    Nahavandi, A.N.; Oellinger, J.

    1977-01-01

    A rigorous approach is applied to the thermal design of counterflow cooling towers, by obviating the six simplifying assumptions in the classical Merkel method. It is indicated that: (1) neglecting evaporation losses is the main cause of inaccuracy in the Merkel results; (2) the error in the Merkel method may reach 12%; and (3) the present solution provides a more accurate and more ecologically favorable prediction for the cooling water tower. (Auth.)

  16. A Meso-Climatology Study of the High-Resolution Tower Network Over the Florida Spaceport

    Science.gov (United States)

    Case, Jonathan L.; Bauman, William H., III

    2004-01-01

    Forecasters at the US Air Force 45th Weather Squadron (45 WS) use wind and temperature data from the tower network over the Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) to evaluate Launch Commit Criteria and to issue and verify temperature and wind advisories, watches, and warnings for ground operations. The Spaceflight Meteorology Group at the Johnson Space Center in Houston, TX also uses these data when issuing forecasts for shuttle landings at the KSC Shuttle Landing Facility. Systematic biases in these parameters at any of the towers could adversely affect an analysis, forecast, or verification for all of these operations. In addition, substantial geographical variations in temperature and wind speed can occur under specific wind directions. Therefore, the Applied Meteorology Unit (AMU), operated by ENSCO Inc., was tasked to develop a monthly and hourly climatology of temperatures and winds from the tower network, and identify the geographical variation, tower biases, and the magnitude of those biases. This paper presents a sub-set of results from a nine-year climatology of the KSC/CCAFS tower network, highlighting the geographical variations based on location, month, times of day, and specific wind direction regime. Section 2 provides a description of the tower mesonetwork and instrumentation characteristics. Section 3 presents the methodology used to construct the tower climatology including QC methods and data processing. The results of the tower climatology are presented in Section 4 and Section 5 summarizes the paper.

  17. Vibration analysis of three guyed tower designs for intermediate size wind turbines

    Science.gov (United States)

    Christie, R. J.

    1982-01-01

    Three guyed tower designs were analyzed for intermediate size wind turbines. The four lowest natural frequencies of vibration of the three towers concepts were estimated. A parametric study was performed on each tower to determine the effect of varying such tower properties as the inertia and stiffness of the tower and guys, the inertia values of the nacelle and rotor, and the rotational speed of the rotor. Only the two lowest frequencies were in a range where they could be excited by the rotor blade passing frequencies. There two frequencies could be tuned by varying the guy stiffness, the guy attachment point on the tower, the tower and mass stiffness, and the nacelle/rotor/power train masses.

  18. Whitney towers, Gropes and Casson-Gordon style invariants of links

    OpenAIRE

    Kim, Min Hoon

    2014-01-01

    In this paper, we prove a conjecture of Friedl and Powell that their Casson-Gordon type invariant of 2-component link with linking number one is actually an obstruction to being height 3.5 Whitney tower/grope concordant to the Hopf Link. The proof employs the notion of solvable cobordism of 3-manifolds with boundary, which was introduced by Cha. We also prove that the Blanchfield form and the Alexander polynomial of links in $S^3$ give obstructions to height 3 Whitney tower/grope concordance....

  19. Hadron calorimeter towers with a high space resolution

    International Nuclear Information System (INIS)

    Bellettini, G.; Bertani, R.; Bradaschia, C.; Del Fabbro, R.; Scribano, A.; Terreni, G.

    1982-01-01

    The performances of a set of hadron calorimeter towers for measuring the hadron impact point are described. It is shown that an accuracy of 1-2 cm can be achieved with a proper treatment of the data. (orig.)

  20. Performance Evaluation of a Mechanical Draft Cross Flow Cooling Towers Employed in a Subtropical Region

    Science.gov (United States)

    Muthukumar, Palanisamy; Naik, Bukke Kiran; Goswami, Amarendra

    2018-02-01

    Mechanical draft cross flow cooling towers are generally used in a large-scale water cooled condenser based air-conditioning plants for removing heat from warm water which comes out from the condensing unit. During this process considerable amount of water in the form of drift (droplets) and evaporation is carried away along with the circulated air. In this paper, the performance evaluation of a standard cross flow induced draft cooling tower in terms of water loss, range, approach and cooling tower efficiency are presented. Extensive experimental studies have been carried out in three cooling towers employed in a water cooled condenser based 1200 TR A/C plant over a period of time. Daily variation of average water loss and cooling tower performance parameters have been reported for some selected days. The reported average water loss from three cooling towers is 4080 l/h and the estimated average water loss per TR per h is about 3.1 l at an average relative humidity (RH) of 83%. The water loss during peak hours (2 pm) is about 3.4 l/h-TR corresponding to 88% of RH and the corresponding efficiency of cooling towers varied between 25% and 45%.

  1. Volatile Organic Carbon Emissions. Phase 2.

    Science.gov (United States)

    1987-02-01

    accumulating in the automatic sample injection syringe in the GC thereby causing low analytical analyses of the absortent solutions. Figures 6 and 7 show...up, % total solids vs % Na2S205 titrated by iodine , and % Na2S205 titrated by iodine vs % Na2S205 made-up. These solutions were evaluated in the RAAP...consists of a dual-column system for solvent absorption, two distillation towers for solvent recovery, and an abatement facility for treating residual

  2. Natural-draught cooling towers made of reinforced concrete

    International Nuclear Information System (INIS)

    Kraetzig, W.B.; Peters, H.L.; Zerna, W.

    1978-01-01

    Large power plant units and dry cooling tower technology require larger dimensions for natural-draught cooling towers. The main curvation radii in latitudinal and meridian direction are thus increased, which results in a lower three-dimensional support strength. This development is an incentive for constant re-consideration of calculation methods, safety philosophy, and dimensioning criteria. In this context, wind effects have been re-formulated and given a scientific foundation. Constructional measures to improve the static and dynamic behaviour of the structure have been presented and critically assessed. A cost analysis, finally, gave the most rational applications of the new shell construction with reinforcing elements. A cooling tower now under construction gave a realistic example. Fundamental aspects concerning the foundations of cooling tower shells and two special types of foundation are further points to clarify the subject. (orig./HP) [de

  3. TacTowers

    DEFF Research Database (Denmark)

    Ludvigsen, Martin; Fogtmann, Maiken Hillerup; Grønbæk, Kaj

    2010-01-01

    The interactive training equipment, TacTower, is aimed at supporting multiple elite athletes, such as handball players in training their micro-tactical skills in close-contact situations. It focuses on psychomotor abilities and trains the skills involved in reading the opponents’ actions and anti...... for the elite athletic community, as this domain holds interesting challenges while also inspiring relevant, new forms of interaction design for other domains....

  4. Dynamic behavior and identification of failure modes of cooling towers

    International Nuclear Information System (INIS)

    Serhan, S.J.

    1994-01-01

    The major thrust of this paper is to provide an engineering assessment of two hyperboloidal 540-foot high reinforced concrete cooling towers at a nuclear power plant relative to the proposed construction of a new safety-related facility in the shadow of these cooling towers. A three-dimensional full 360-degree finite-element model that is capable of realistically representing the response of the two cooling towers subjected to the plant design-basis safe shutdown earthquake, 90 mph wind, and 300 mph tornado is used to create a data pool which supports the proposed construction of the new facility. Dynamic time history analyses are performed to represent the complex interplay of the dynamic characteristics of the cooling towers and the input wind-pressure excitation in terms of gust factors. This study resulted in the confirmation and enhancement of many of the important aspects in the design/analysis methodologies for cooling towers reported in literature. In summary, this study provides a high confidence that no significant damage will be caused to the two cooling towers when subjected to the plant design-basis safe shutdown earthquake and the 90 mph basic wind velocity. However, the two cooling towers are expected to collapse if subjected in a direct hit to a 300 mph tornado. The nonlinear finite element analyses including base uplift performed for this study and the literature research on past failures of cooling towers due to severe wind storms confirm that the mode of failure will not be the overturning cantilever tree-type and the towers will collapse inwardly with the exception of few isolated debris

  5. TileCal Trigger Tower studies considering additional segmentation on the ATLAS upgrade for high luminosity at LHC

    CERN Document Server

    March, L; The ATLAS collaboration

    2013-01-01

    The Tile Calorimeter (TileCal) is the hadronic calorimeter covering the most central region of the ATLAS experiment at LHC. The TileCal readout consists of about 10000 channels and provides a compact information, called trigger towers (around 2000 signals), to the ATLAS first level online event selection system. The ATLAS upgrade program is divided in three phases: Phase 0 occurs during 2013- 2014 and prepares the LHC to reach peak luminosities of 10^34 cm2s-1; Phase 1, foreseen for 2018-1019, prepares the LHC for peak luminosity up to 2-3 x 10^34 cm2s-1, corresponding to 55 to 80 interactions per bunch-crossing with 25 ns bunch interval; and Phase 2 is foreseen for 2022-2023, whereafter the peak luminosity will reach 5-7 x 1034 cm2s-1 (HL-LHC). The ATLAS experiment is operating very well since 2009 providing large amount of data for physics analysis. The online event selection system (trigger system) was designed to reject the huge amount of background noise generated at LHC and is one of the main systems re...

  6. Radiation scanning aids tower diagnosis at Arun LNG plant

    International Nuclear Information System (INIS)

    Naklie, M.M.; Pless, L.; Gurning, T.P.; Hyasak, M.

    1990-01-01

    Radiation scanning has been used effectively to troubleshoot the treating towers of the Arun LNG plant in Sumatra, Indonesia. The plant is one of the world's largest such facilities. The analysis was part of an investigation aimed at increasing the capacity of the treater section of the plant. Radiation scanning is a tool which, in addition to tower differential pressure and product purity, can aid in diagnosing tower performance

  7. DEVELOPMENT OF METHODS FOR STABILITY ANALYSIS OF TOWER CRANES

    Directory of Open Access Journals (Sweden)

    Sinel'shchikov Aleksey Vladimirovich

    2018-01-01

    Full Text Available Tower cranes are one of the main tools for execution of reloading works during construction. Design of tower cranes is carried out in accordance with RD 22-166-86 “Construction of tower cranes. Rules of analysis”, according to which to ensure stability it is required not to exceed the overturning moment upper limit. The calculation of these moments is carried out with the use of empirical coefficients and quite time-consuming. Moreover, normative methodology only considers the static position of the crane and does not take into account the presence of dynamic transients due to crane functioning (lifting and swinging of the load, boom turning and the presence of the dynamic external load (e.g. from wind for different orientations of the crane. This paper proposes a method of determining the stability coefficient of the crane based on acting reaction forces at the support points - the points of contact of wheels with the crane rail track, which allows us, at the design stage, to investigate stability of tower crane under variable external loads and operating conditions. Subject: the safety of tower cranes operation with regard to compliance with regulatory requirements of ensuring their stability both at the design stage and at the operational stage. Research objectives: increasing the safety of operation of tower cranes on the basis of improving methodology of their design to ensure static and dynamic stability. Materials and methods: analysis and synthesis of the regulatory framework and modern research works on provision of safe operation of tower cranes, the method of numerical simulation. Results: we proposed the formula for analysis of stability of tower cranes using the resulting reaction forces at the supports of the crane at the point of contact of the wheel with the rail track.

  8. Optimization of cooling tower performance analysis using Taguchi method

    Directory of Open Access Journals (Sweden)

    Ramkumar Ramakrishnan

    2013-01-01

    Full Text Available This study discuss the application of Taguchi method in assessing maximum cooling tower effectiveness for the counter flow cooling tower using expanded wire mesh packing. The experiments were planned based on Taguchi’s L27 orthogonal array .The trail was performed under different inlet conditions of flow rate of water, air and water temperature. Signal-to-noise ratio (S/N analysis, analysis of variance (ANOVA and regression were carried out in order to determine the effects of process parameters on cooling tower effectiveness and to identity optimal factor settings. Finally confirmation tests verified this reliability of Taguchi method for optimization of counter flow cooling tower performance with sufficient accuracy.

  9. Solution and scope of utilization of the cross-stream cooling towers

    International Nuclear Information System (INIS)

    Zembaty, W.

    1995-01-01

    Technical solutions and operational properties of the cross-stream cooling towers as well as the scope of their utilization are presented. The differences within thermodynamic calculations of the cross-stream and counter-stream cooling towers due to the direction of the air flow as well as water flow in sprinkling system are discussed. The assessment of the capital and operational costs of the cross-stream cooling towers is given and compared with the cost of counter-stream cooling towers (utilizing as an example a calculation conducted for the cooling towers of the 720, 1100 and 1400 MW units). (author). 6 refs, 9 figs

  10. FLUXNET: A Global Network of Eddy-Covariance Flux Towers

    Science.gov (United States)

    Cook, R. B.; Holladay, S. K.; Margle, S. M.; Olsen, L. M.; Gu, L.; Heinsch, F.; Baldocchi, D.

    2003-12-01

    The FLUXNET global network was established to aid in understanding the mechanisms controlling the exchanges of carbon dioxide, water vapor, and energy across a variety of terrestrial ecosystems. Flux tower data are also being used to validate ecosystem model outputs and to provide information for validating remote sensing based products, including surface temperature, reflectance, albedo, vegetation indices, leaf area index, photosynthetically active radiation, and photosynthesis derived from MODIS sensors on the Terra and Aqua satellites. The global FLUXNET database provides consistent and complete flux data to support global carbon cycle science. Currently FLUXNET consists of over 210 sites, with most flux towers operating continuously for 4 years or longer. Gap-filled data are available for 53 sites. The FLUXNET database contains carbon, water vapor, sensible heat, momentum, and radiation flux measurements with associated ancillary and value-added data products. Towers are located in temperate conifer and broadleaf forests, tropical and boreal forests, crops, grasslands, chaparral, wetlands, and tundra on five continents. Selected MODIS Land products in the immediate vicinity of the flux tower are subsetted and posted on the FLUXNET Web site for 169 flux-towers. The MODIS subsets are prepared in ASCII format for 8-day periods for an area 7 x 7 km around the tower.

  11. Numerical Simulation of Tower Rotor Interaction for Downwind Wind Turbine

    Directory of Open Access Journals (Sweden)

    Isam Janajreh

    2010-01-01

    Full Text Available Downwind wind turbines have lower upwind rotor misalignment, and thus lower turning moment and self-steered advantage over the upwind configuration. In this paper, numerical simulation to the downwind turbine is conducted to investigate the interaction between the tower and the blade during the intrinsic passage of the rotor in the wake of the tower. The moving rotor has been accounted for via ALE formulation of the incompressible, unsteady, turbulent Navier-Stokes equations. The localized CP, CL, and CD are computed and compared to undisturbed flow evaluated by Panel method. The time history of the CP, aerodynamic forces (CL and CD, as well as moments were evaluated for three cross-sectional tower; asymmetrical airfoil (NACA0012 having four times the rotor's chord length, and two circular cross-sections having four and two chords lengths of the rotor's chord. 5%, 17%, and 57% reductions of the aerodynamic lift forces during the blade passage in the wake of the symmetrical airfoil tower, small circular cross-section tower and large circular cross-section tower were observed, respectively. The pronounced reduction, however, is confined to a short time/distance of three rotor chords. A net forward impulsive force is also observed on the tower due to the high speed rotor motion.

  12. Distributed fiber optic interferometric geophone system based on draw tower gratings

    Science.gov (United States)

    Xu, Ruquan; Guo, Huiyong; Liang, Lei

    2017-09-01

    A distributed fiber optic interferometric geophone array based on draw tower grating (DTG) array is proposed. The DTG geophone array is made by the DTG array fabricated based on a near-contact exposure through a phase mask during the fiber drawing process. A distributed sensing system with 96 identical DTGs in an equal separation of 20 m and an unbalanced Michelson interferometer for vibration measurement has been experimentally validated compared with a moving-coil geophone. The experimental results indicate that the sensing system can linearly demodulate the phase shift. Compared with the moving coil geophone, the fiber optic sensing system based on DTG has higher signal-to-noise ratio at low frequency.

  13. Wind-induced Vibrations in the European Court Towers

    DEFF Research Database (Denmark)

    Hansen, Jannick B.; Brincker, Rune; Andersen, Ken G.

    2012-01-01

    Issues regarding occupancy comfort in vibration-sensitive structures are the motivation of this study concerning windinduced vibrations in the European Court Towers in Luxembourg. In one of the two identical towers tuned liquid dampers (TLD) have been installed. Recent studies investigate the cha...

  14. Reality based optimization of steel monopod offshore-towers

    NARCIS (Netherlands)

    Vrouwenvelder, A.C.W.M.

    2008-01-01

    In this work, the implementation of reliability-based optimization (RBO) of a circular steel monopod-offshore-tower with constant and variable diameters (represented by segmentations) and thicknesses is presented. The tower is subjected to the extreme wave loading. For this purpose, the

  15. Distance protection of multiple-circuit shared tower transmission lines with different voltages

    DEFF Research Database (Denmark)

    Silva, Filipe Miguel Faria da; Bak, Claus Leth

    2017-01-01

    combined faults, being advised to increase the resistive limit of the protection zone, if the network has lower short-circuit power. It is recommended to assure that the fault can only happen for cases where the faulted phase from the higher voltage level leads the faulted phase from the lower voltage......Multiple-circuit transmission lines combining different voltage levels in one tower present extra challenges when setting a protection philosophy, as faults between voltage levels are possible. In this study, the fault loop impedance of combined faults is compared with the fault loop impedance......-phase-to-ground faults. It is also demonstrated that the fault loop impedance of combined faults is more resistive, when compared with equivalent single-phase-to-ground faults. It is concluded that the settings used to protect a line against single-phase-to-ground faults are capable of protecting the line against...

  16. Cooling tower wood sampling and analyses: A case study

    International Nuclear Information System (INIS)

    Haymore, J.L.

    1985-01-01

    Extensive wood sampling and analyses programs were initiated on crossflow and counterflow cooling towers that have been in service since 1951 and 1955, respectively. Wood samples were taken from all areas of the towers and were subjected to biological, chemical and physical tests. The tests and results for the analyses are discussed. The results indicate the degree of wood deterioration, and areas of the towers which experience the most advanced degree of degradation

  17. Variation in agricultural CO2 fluxes during the growing season, collected from more than ten eddy covariance towers in the Mississippi Delta Region

    Science.gov (United States)

    Runkle, B.; Suvocarev, K.; Reba, M. L.; Novick, K. A.; White, P.; Anapalli, S.; Locke, M. A.; Rigby, J.; Bhattacharjee, J.

    2016-12-01

    Agriculture is unique as an anthropogenic activity that plays both a large role in carbon and water cycling and whose management activities provide a key opportunity for responses to climate change. It is therefore especially crucial to bring field observations into the modeling community, test remote sensing products, encourage policy debate, and enable carbon offsets markets that generate revenue and fund climate-smart activities. The accurate measurement of agricultural CO2 exchange - both primary productivity and ecosystem respiration - in concert with evapotranspiration provides crucial information on agro-ecosystem functioning and improves our predictive capacity for estimating the impacts of climate change. In this study we report field measurements from more than 10 eddy covariance towers in the Lower Mississippi River Basin taken during the summer months of 2016. Many towers, some recently deployed, are being aggregated into a regional network known as Delta-Flux, which will ultimately include 15-20 towers by 2017. Set in and around the Mississippi Delta Region within Louisiana, Arkansas, and Mississippi, the network will collect flux, micrometeorological, and crop yield data in order to construct estimates of regional CO2 exchange. These time-series data are gap-filled using statistical and process-based models to generate estimates of summer CO2 flux. The tower network is comprised of sites representing widespread agriculture production, including rice, cotton, corn, soybean, and sugarcane; intensively managed pine forest; and bottomland hardwood forest. Unique experimental production practices are represented in the network and include restricted water use, bioenergy, and by-product utilization. Several towers compose multi-field sites testing innovative irrigation or management practices. Current mapping of agricultural carbon exchange - based on land cover layers and fixed crop emission factors - suggests an unconstrained carbon flux estimate in this

  18. EDF's ageing management program for cooling towers

    International Nuclear Information System (INIS)

    Roure, T.; Crolet, Y.

    2015-01-01

    EDF operates a large fleet of cooling towers for its thermal and nuclear plants. Proactive maintenance strategies require ranking the towers according to the risk of failure and the observed damage. The ranking includes monitoring data such as: foundation settlements, material properties, quantified crack patterns, shell deformation, meteorological data, and corrosion. The numerical tool suite includes a finite element analysis of each tower under thermal and mechanical loadings and a corrosion predicting tool, based on carbonation. The first module computes the behavior of cooling towers under five types of loading: soil differential settlement, self-weight, moisture transport, temperature and wind. By comparison with the ultimate resisting capacity of the reinforced concrete cross section, a risk index map is produced for each tower. This risk index is used to rank the cooling towers and then to identify which structures should be monitored more closely or reinforced - if needed - first in the case of an extended operating life. The second module aims to anticipate the corrosion depth of reinforcement steel of the towers in the future. Examination of the existing carbonation is currently done for each structure and evolution of the carbonation depth is computed so as to predict with reasonable assurance when carbonation reaches the rebars. A prediction of the eventual cross-section loss of rebars is then made for long term analysis (i.e. up to 60 years of operating life). When corrosion is predicted the first module takes into account this loss and computes the behavior of the predicted corrosion damaged structure under the same loadings. (authors)

  19. Failure of the Nemo trial: bumetanide is a promising agent to treat many brain disorders but not newborn seizures

    Directory of Open Access Journals (Sweden)

    Yehezkel eBen-Ari

    2016-04-01

    Full Text Available The diuretic bumetanide failed to treat acute seizures due to hypoxic ischemic encephalopathy (HIE in newborn babies and was associated with hearing loss (NEMO trial; 1. On the other hand, clinical and experimental observations suggest that the diuretic might provide novel therapy for many brain disorders including autistic spectrum disorder, schizophrenia, Rett syndrome and Parkinson disease. Here, we discuss the differences between the pathophysiology of severe recurrent seizures in the neonates and neurological and psychiatric disorders stressing the uniqueness of severe seizures in newborn in comparison to other disorders.

  20. 75 FR 63802 - Action Affecting Export Privileges; Parto Abgardan Cooling Towers Co.

    Science.gov (United States)

    2010-10-18

    ... Abgardan Cooling Towers Co. Parto Abgardan Cooling Towers Co., P.O. Box 966, Folsom, CA 95763; and P.O. Box... Making Denial of Export Privileges of Aqua-Loop Cooling Towers, Co. Applicable to Parto Abgardan Cooling...-Loop Cooling Towers, Co. (``Aqua-Loop'') on March 25, 2010 (``Denial Order''), applicable to the...

  1. The optimal operation of cooling tower systems with variable-frequency control

    Science.gov (United States)

    Cao, Yong; Huang, Liqing; Cui, Zhiguo; Liu, Jing

    2018-02-01

    This study investigates the energy performance of chiller and cooling tower systems integrated with variable-frequency control for cooling tower fans and condenser water pumps. With regard to an example chiller system serving an office building, Chiller and cooling towers models were developed to assess how different variable-frequency control methods of cooling towers fans and condenser water pumps influence the trade-off between the chiller power, pump power and fan power under various operating conditions. The matching relationship between the cooling tower fans frequency and condenser water pumps frequency at optimal energy consumption of the system is introduced to achieve optimum system performance.

  2. Legionella safety in cooling towers; Legionellaveiligheid in koeltorens

    Energy Technology Data Exchange (ETDEWEB)

    Kordes, B. [Kordes Advies, (Netherlands); De Bok, F. [KBBL Wijhe, (Netherlands); De Zeeuw, L. [Holland Environment Group, (Netherlands); Settels, P. [Safety, Health Services and Ergonomics, ING, (Netherlands); Oesterholt, F.; Wullings, B. [KWR Watercycle Research Institute, (Netherlands); Guiot, P. [Tevan, Gorinchem (Netherlands); Brands, R. [Cumulus Nederland, Cuijk (Netherlands); Nuijten, O. [Kennisinstituut ISSO, Rotterdam (Netherlands); Wijne, R. [Beer advocaten, Amsterdam (Netherlands)

    2010-04-15

    In 9 articles attention is paid to several aspects with regard to Legionella in cooling towers: representative sampling, the use of copper and silver ionization or hydrogen peroxide to prevent Legionella growth and biofilms, the use of a zero-tolerance model to control a cooling tower installation, detection of DNA of Legionella Pneumophila, legionella safety in air conditioners, the model Legionella risk analysis and control of cooling tower installations, legislation and regulations for the control of cooling tower installations with regard to the Dutch Occupational Health and Safety Act ('Arbo-wet'), and an article about a lawsuit for victims of a Legionella outbreak, caused by careless owners of a cooling tower in Amsterdam, Netherlands. [Dutch] In 9 artikelen wordt in deze aflevering aandacht besteed aan verschillende aspecten m.b.t. Legionella in koeltorens: representatieve monstername, de toepassing van koper en zilver-ionisatie of waterstofperoxide om de groei van Legionella en biofilms te voorkomen, het gebruik van een zero-tolerance model om een koeltoren installatie te controleren, detectie van DNA van Legionella Pneumophila, Legionella veiligheid in luchtbehandelingsinstallaties, het model Legionella risicoanalyse en beheersplan voor koeltoreninstallaties, de rol van de Arbo-wet, en een artikel over een rechtszaak voor slachtoffers van Legionella door onzorgvuldig beheer van een koeltoren in Amsterdam.

  3. Novel partial-subsidence tower-type boiler design in an ultra-supercritical power plant

    International Nuclear Information System (INIS)

    Xu, Gang; Xu, Cheng; Yang, Yongping; Fang, Yaxiong; Zhou, Luyao; Zhang, Kai

    2014-01-01

    Highlights: • The two-pass type and tower-type boilers were compared. • A novel partial-subsidence tower-type boiler design was proposed. • Thermodynamic and economic analyses were quantitatively conducted. • The application of the partial-subsidence boiler to a 700 °C stage unit was further analyzed. - Abstract: An increasing number of tower-type boilers have been applied to ultra-supercritical power plants because of the simple design of the membrane walls and the smooth increase in temperature of such boilers. Nevertheless, the significant height and long steam pipelines of this boiler type will expand the power plant investment cost and increase steam-side pressure losses, especially for higher parameters units requiring high costs of nickel-based alloy materials. Thus, a novel partial-subsidence tower-type boiler design was proposed. In this boiler type, nearly 1/22/3 of the boiler height was embedded underground to reduce the height of the boiler and the length of the steam pipelines significantly. Thermodynamic and economic analyses were conducted on a state-of-the-art 1000 MW ultra-supercritical power plant and a prospective 700 °C-stage double reheat power plant. Results showed that the proposed tower-type boiler design could result in a 0.1% point increase in net efficiency and a $0.56/MW h reduction in the cost of electricity in a 1000 MW power plant. This economic benefit was enhanced for power plants with higher steam parameters and larger capacity. The concept of the proposed boiler design may provide a promising method for tower-type boiler applications, especially in new-generation double reheat plants with higher parameters

  4. Use of cooling tower blow down in ethanol fermentation.

    Science.gov (United States)

    Rajagopalan, N; Singh, V; Panno, B; Wilcoxon, M

    2010-01-01

    Reducing water consumption in bioethanol production conserves an increasingly scarce natural resource, lowers production costs, and minimizes effluent management issues. The suitability of cooling tower blow down water for reuse in fermentation was investigated as a means to lower water consumption. Extensive chemical characterization of the blow down water revealed low concentrations of toxic elements and total dissolved solids. Fermentation carried out with cooling tower blow down water resulted in similar levels of ethanol and residual glucose as a control study using deionized water. The study noted good tolerance by yeast to the specific scale and corrosion inhibitors found in the cooling tower blow down water. This research indicates that, under appropriate conditions, reuse of blow down water from cooling towers in fermentation is feasible.

  5. Potential weather modification caused by waste heat release from large dry cooling towers

    International Nuclear Information System (INIS)

    Lee, J.

    1979-01-01

    A numerical model of a cooling tower plume is employed to study the possible atmospheric effects of thermal plumes from natural draft dry cooling towers. Calculations are performed for both single and multiple towers, each of which can dissipate the waste heat from a nominal 1000 MWe power generating unit, and the results are compared with those for wet cooling towers associated with plants of the same generating capacity. Dry cooling tower plumes are found to have a higher potential for inducing convective clouds than wet cooling tower plumes, under most summertime meteorological conditions. This is due to the fact that both the sensible heat and momentum fluxes from a dry tower in summer are approximately one order of magnitude larger than those from a wet cooling tower

  6. Cooling towers in the landscape

    International Nuclear Information System (INIS)

    Boernke, F.

    1977-01-01

    The cooling tower as a large technical construction is one of the most original industrial buildings. It sticks out as an outlandish element in our building landscape, a giant which cannot be compared with the traditional forms of technical buildings. If it is constructed as a reinforced-concrete hyperboloid, its shape goes beyond all limits of building construction. Judgment of these highly individual constructions is only possible by applying a novel standard breaking completely with tradition. This new scale of height and dimension in industrial construction, and in particular the modern cooling tower, requires painstaking care and design and adaptation to the landscape around it. (orig.) [de

  7. Windfarms and telecommunications towers (Scotland)

    Energy Technology Data Exchange (ETDEWEB)

    Munro, Hector; Kellett-Bowman, Elaine; Harris, David [and others

    1996-10-30

    A debate in the United Kingdom House of Commons on the environmental impact of windfarms and telecommunications towers in Scotland is reported. Concern was expressed over the adverse visual impact of such structures in rural areas which are often of considerable natural beauty. Counter arguments were based on the positive effects of new technology. The need to reconcile environmental protection with technological innovation was expressed. A Government spokesman described the comprehensive planning policy framework which has been put in place to secure sound planning decisions on renewable energy developments and the conditions on amenity protection in the regulations governing the erection of telecommunications towers. (UK)

  8. Windfarms and telecommunications towers (Scotland)

    International Nuclear Information System (INIS)

    Munro, Hector; Kellett-Bowman, Elaine; Harris, David

    1996-01-01

    A debate in the United Kingdom House of Commons on the environmental impact of windfarms and telecommunications towers in Scotland is reported. Concern was expressed over the adverse visual impact of such structures in rural areas which are often of considerable natural beauty. Counter arguments were based on the positive effects of new technology. The need to reconcile environmental protection with technological innovation was expressed. A Government spokesman described the comprehensive planning policy framework which has been put in place to secure sound planning decisions on renewable energy developments and the conditions on amenity protection in the regulations governing the erection of telecommunications towers. (UK)

  9. Performance Evaluation of a Modular Design of Wind Tower with Wetted Surfaces

    Directory of Open Access Journals (Sweden)

    Sajad M.R. Khani

    2017-06-01

    Full Text Available Wind towers or wind catchers, as passive cooling systems, can provide natural ventilation in buildings located in hot, arid regions. These natural cooling systems can provide thermal comfort for the building inhabitants throughout the warm months. In this paper, a modular design of a wind tower is introduced. The design, called a modular wind tower with wetted surfaces, was investigated experimentally and analytically. To determine the performance of the wind tower, air temperature, relative humidity (RH and air velocity were measured at different points. Measurements were carried out when the wind speed was zero. The experimental results were compared with the analytical ones. The results illustrated that the modular wind tower can decrease the air temperature significantly and increase the relative humidity of airflow into the building. The average differences for air temperature and air relative humidity between ambient air and air exiting from the wind tower were approximately 10 °C and 40%, respectively. The main advantage of the proposed wind tower is that it is a modular design that can reduce the cost of wind tower construction.

  10. Wind turbine generator application places unique demands on tower design and materials

    Science.gov (United States)

    Kita, J. P.

    1978-01-01

    The most relevant contractual tower design requirements and goal for the Mod-1 tower are related to steel truss tower construction, cost-effective state-of-the-art design, a design life of 30 years, and maximum wind conditions of 120 mph at 30 feet elevation. The Mod-1 tower design approach was an iterative process. Static design loads were calculated and member sizes and overall geometry chosen with the use of finite element computer techniques. Initial tower dynamic characteristics were then combined with the dynamic properties of the other wind turbine components, and a series of complex dynamic computer programs were run to establish a dynamic load set and then a second tower design.

  11. Evaluation of Tower Shadowing on Anemometer Measurements at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Bruggeman, David Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-14

    The objective of this study is to evaluate the effect of tower shadowing from the meteorology towers at LANL during 2014. This study is in response to the Department of Energy Meteorological Coordinating Council visit in 2015 that recommended an evaluation of any biases in the wind data introduced by the tower and boom alignment at all meteorology towers.

  12. Lower parts of Temelin nuclear power plant cooling towers

    International Nuclear Information System (INIS)

    Sebek, J.

    1988-01-01

    The progress of work is described in detail on the foundations and lower parts of the cooling towers of the Temelin nuclear power plant. The cooling tower is placed on a reinforced concrete footing of a circular layout. Support pillars are erected on the reinforced concrete continuous footing. They consists of oblique shell stanchions. Inside, the footing joins up to monolithic wall and slab structures of the cooling tower tub. The tub bottom forms a foundation plate supporting prefab structures of the cooling tower inner structural systems. The framed support of the chimney shell consists of 56 pairs of prefabricated oblique stanchions. Following their erection into the final position and anchoring in the continuous footing, the concreting of the casing can start of the reinforced conrete chimney. (Z.M.). 3 figs

  13. Parametric study of closed wet cooling tower thermal performance

    Science.gov (United States)

    Qasim, S. M.; Hayder, M. J.

    2017-08-01

    The present study involves experimental and theoretical analysis to evaluate the thermal performance of modified Closed Wet Cooling Tower (CWCT). The experimental study includes: design, manufacture and testing prototype of a modified counter flow forced draft CWCT. The modification based on addition packing to the conventional CWCT. A series of experiments was carried out at different operational parameters. In view of energy analysis, the thermal performance parameters of the tower are: cooling range, tower approach, cooling capacity, thermal efficiency, heat and mass transfer coefficients. The theoretical study included develops Artificial Neural Network (ANN) models to predicting various thermal performance parameters of the tower. Utilizing experimental data for training and testing, the models simulated by multi-layer back propagation algorithm for varying all operational parameters stated in experimental test.

  14. Transient Simulation of Wind Turbine Towers under Lightning Stroke

    Directory of Open Access Journals (Sweden)

    Xiaoqing Zhang

    2013-01-01

    Full Text Available A simulation algorithm is proposed in this paper for lightning transient analysis of the wind turbine (WT towers. In the proposed algorithm, the tower body is first subdivided into a discrete multiconductor system. A set of formulas are given to calculate the electrical parameters of the branches in the multiconductor system. By means of the electrical parameters, each branch unit in the multiconductor system is replaced as a coupled π-type circuit and the multiconductor system is converted into a circuit model. Then, the lightning transient responses can be obtained in different parts on the tower body by solving the circuit equations of the equivalent discretization network. The laboratory measurement is also made by a reduced-scale tower for checking the validity of the proposed algorithm.

  15. Exergy analysis of a distillation tower for crude oil fractionation

    International Nuclear Information System (INIS)

    Rivero, R.

    1990-01-01

    In this paper the application of the exergy method to a crude oil atmospheric distillation tower is presented. The fundamentals and procedures are presented as well as the main parameters used to describe the thermodynamic performance of the system, such as Exergy Losses, Effectiveness and Improvement Potential. A parametric analysis of the influence on the effectiveness of the tower is then performed as a function of the number of trays, the amount of stripping steam, the use of reboilers and the operation pressure. The results obtained are discussed. As expected, the effectiveness of the tower increases with the overall number of trays in the tower and in the stripping columns for a constant operation pressure and a constant amount of stripping steam but there is a limit at which the pressure drop across the trays and the stripping steam requirements make the effectiveness decrease. The use of reboilers in the stripping columns adjacent to the main tower allows an increase in the effectiveness basically due to a greater heat integration. Finally, the increase in the operation pressure of the tower produces an increase of the effectiveness but also an increase in the stripping steam requirements

  16. Power fluctuation and power loss of wind turbines due to wind shear and tower shadow

    Institute of Scientific and Technical Information of China (English)

    Binrong WEN; Sha WEI; Kexiang WEI; Wenxian YANG; Zhike PENG; Fulei CHU

    2017-01-01

    The magnitude and stability of power output are two key indices of wind turbines.This study investigates the effects of wind shear and tower shadow on power output in terms of power fluctuation and power loss to estimate the capacity and quality of the power generated by a wind turbine.First,wind speed models,particularly the wind shear model and the tower shadow model,are described in detail.The widely accepted tower shadow model is modified in view of the cone-shaped towers of modem large-scale wind turbines.Power fluctuation and power loss due to wind shear and tower shadow are analyzed by performing theoretical calculations and case analysis within the framework of a modified version of blade element momentum theory.Results indicate that power fluctuation is mainly caused by tower shadow,whereas power loss is primarily induced by wind shear.Under steady wind conditions,power loss can be divided into wind farm loss and rotor loss.Wind farm loss is constant at 3α(3α-1)R2/(8H2).By contrast,rotor loss is strongly influenced by the wind turbine control strategies and wind speed.That is,when the wind speed is measured in a region where a variable-speed controller works,the rotor loss stabilizes around zero,but when the wind speed is measured in a region where the blade pitch controller works,the rotor loss increases as the wind speed intensifies.The results of this study can serve as a reference for accurate power estimation and strategy development to mitigate the fluctuations in aerodynamic loads and power output due to wind shear and tower shadow.

  17. NEON's Eddy-Covariance Storage Exchange: from Tower to Data Portal

    Science.gov (United States)

    Durden, N. P.; Luo, H.; Xu, K.; Metzger, S.; Durden, D.

    2017-12-01

    NEON's eddy-covariance storage exchange system (ECSE) consists of a suite of sensors including temperature sensors, a CO2 and H2O gas analyzer, and isotopic CO2 and H2O analyzers. NEON's ECSE was developed to provide the vertical profile measurements of temperature, CO2 and H2O concentrations, the stable isotope ratios in CO2 (δ13C) and H2O (δ18O and δ2H) in the atmosphere. The profiles of temperature and concentrations of CO2 and H2O are key to calculate storage fluxes for eddy-covariance tower sites. Storage fluxes have a strong diurnal cycle and can be large in magnitude, especially at temporal scales less than one day. However, the storage term is often neglected in flux computations. To obtian accurate eddy-covariance fluxes, the storage fluxes are calculated and incorporated into the calculations of net surface-atmosphere ecosystem exchange of heat, CO2, and H2O for each NEON tower site. Once the ECSE raw data (Level 0, or L0) is retrieved at NEON's headquarters, it is preconditioned through a sequence of unit conversion, time regularization, and plausibility tests. By utilizing NEON's eddy4R framework (Metzger et al., 2017), higher-level data products are generated including: Level 1 (L1): Measurement-level specific averages of temperature and concentrations of CO2 and H2O. Level 2 (L2): Time rate of change of temperature and concentrations of CO2 and H2O over 30 min at each measurement level along the vertical tower profile. Level 3 (L3): Time rate of change of temperature and concentrations of CO2 and H2O over 30 min (L2), spatially interpolated along the vertical tower profile. Level 4 (L4): Storage fluxes of heat, CO2, and H2O calculated from the integrated time rate of change spatially interpolated profile (L3). The L4 storage fluxes are combined with turbulent fluxes to calculate the net surface-atmosphere ecosystem exchange of heat, CO2, and H2O. Moreover, a final quality flag and uncertainty budget are produced individually for each data stream

  18. IκB Kinase 2 Is Essential for IgE-Induced Mast Cell De Novo Cytokine Production but Not for Degranulation

    Directory of Open Access Journals (Sweden)

    Katrin Peschke

    2014-09-01

    Full Text Available The immunoglobulin E (IgE-mediated mast cell (MC response is central to the pathogenesis of type I allergy and asthma. IκB kinase 2 (IKK2 was reported to couple IgE-induced signals to MC degranulation by phosphorylating the SNARE protein SNAP23. We investigated MC responses in mice with MC-specific inactivation of IKK2 or NF-κB essential modulator (NEMO, or animals with MC-specific expression of a mutant, constitutively active IKK2. We show that the IgE-induced late-phase cytokine response is reduced in mice lacking IKK2 or NEMO in MCs. However, anaphylactic in vivo responses of these animals are not different from those of control mice, and in vitro IKK2-deficient MCs readily phosphorylate SNAP23 and degranulate similarly to control cells in response to allergen or calcium ionophore. Constitutive overactivation of the NF-κB pathway has only slight effects on allergen-triggered MC responses. Thus, IKK2 is dispensable for MC degranulation, and the important question how IgE-induced signals trigger MC vesicle fusion remains open.

  19. 78 FR 10210 - Utility Scale Wind Towers From China and Vietnam

    Science.gov (United States)

    2013-02-13

    ... wind towers. Background The Commission instituted these investigations effective December 29, 2011...)] Utility Scale Wind Towers From China and Vietnam Determinations On the basis of the record \\1\\ developed... with material injury by reason of imports of utility scale wind towers from China and Vietnam, provided...

  20. Galois towers over non-prime finite fields

    DEFF Research Database (Denmark)

    Bassa, Alp; Beelen, Peter; Garcia, Arnaldo

    2014-01-01

    In this paper we construct Galois towers with good asymptotic properties over any non-prime finite field Fℓ; i.e., we construct sequences of function fields N=(N1⊂N2⊂⋯) over Fℓ of increasing genus, such that all the extensions Ni/N1 are Galois extensions and the number of rational places of these...

  1. Seismic response analysis of column supported natural draught cooling tower shells

    International Nuclear Information System (INIS)

    Ramanjaneyulu, K.; Gopalakrishnan, S.; Appa Rao, T.V.S.R.

    2003-01-01

    Natural draught cooling towers (NDCTs) belong to the category of large civil engineering structures and are commonly used in nuclear or thermal power plants. Detailed dynamic analysis has to be carried out for design of cooling towers subjected to seismic excitation, considering the flexibility of the columns. Finite ring element formulations for dynamic analysis of cooling tower shell subjected to seismic excitation are presented in this paper. The geometry of a typical tall natural draught cooling tower is considered in this study for carrying out investigations. Transient response of the hyperbolic cooling tower shell subjected to earthquake loading has been analysed by direct time integration using acceleration-time history of North-South component of El-Centro earthquake. Parametric studies have also been carried out to study the influence of flexibility of column supports and damping on the seismic response of cooling tower shell and the results are discussed in the paper. (author)

  2. Structural problems in the construction of natural draught cooling towers

    International Nuclear Information System (INIS)

    Zerna, W.

    1977-01-01

    The paper deals with the structural requirements and development possibilities for large cooling towers, and in particular discusses parameter investigations into the reinforcement of cooling tower shells and problems of optimisation. In conclusion proposals are made as to how concrete cooling towers of very large dimensions reinforced with steel, as for example are required in dry cooling for large capacity plant, can be developed economically. (orig.) [de

  3. Industrial cooling tower design and operation in the moderate-continental climate conditions

    Directory of Open Access Journals (Sweden)

    Laković Mirjana S.

    2016-01-01

    Full Text Available A large number of producers offer a wide choice of various types of industrial cooling towers. Usually, a proper choice of pre-fabricated cooling tower satisfies end-user needs. However, if there are specific end-user requirements, it is necessary to design cooling tower according to those requirements. For the adhesive factory located in southern region of Serbia, 350 kW mechanical draught wet cooling tower was designed and built. Dimensioning of the cooling tower was done according to parameters of the ambient air, higher than the standard recommendations given in the literature. In this paper, the reasons for deviation from recommendations are given. The analysis of the cooling tower operation based on real meteorological parameters for 2015 is also shown in this paper. According to this analysis, cooling tower provides required water temperature in any season, and gives opportunity for energy savings in winter, with opportunity for heat capacity enlargement if production capacity is raised as it is planned in the factory.

  4. Numerical study of coupled heat and mass transfer in geothermal water cooling tower

    International Nuclear Information System (INIS)

    Bourouni, K.; Bassem, M.M.; Chaibi, M.T.

    2008-01-01

    Cross flow mechanical cooling towers, widely spreads all over the south region of Tunisia are used for cooling geothermal water for agriculture and domestic ends. These towers are sized empirically and present several problems in regard to operation and electrical energy consumption. This work aims to study the thermal behaviour of this type of cooling towers through a developed mathematical model considering the variation of the water mass flow rate inside the tower. The analysis of the water and air temperatures distribution along the cooling tower had underlined the negative convection phenomenon at a certain height of the tower. This analysis has shown also that the difference in water temperature between the inlet and the outlet of the tower is much higher than the one of air due to the dominance of the evaporative potential compared to the convective one. In addition, the variations of the air humidity along the cooling tower and the quantity of evaporated water have been investigated. The loss of water by evaporation is found to be 5.1% of the total quantity of water feeding the cooling tower. Interesting future prospects are expected for validation of the developed model to optimize the operating of the cooling tower

  5. Large wet-type cooling towers and their influence on the environment

    International Nuclear Information System (INIS)

    Schiffers, A.

    1977-01-01

    Large wet-type cooling towers with natural draft are said to be ecologically beneficial today, especially concerning the heat emission from power plants. A description is given of the influence of such cooling towers on the environment and the possible climatic influences are considered in detail. Recent investigations have shown that wet-type cooling towers represent no danger of any kind for fauna and flora as to the bacterial radiation. Physical studies have shown that neither the emitted water vapour nor the heat emitted into the atmosphere, can significantly change the macroclimate and microclimate. At present, wet-type cooling towers cannot be replaced by dry-type or so-called hybrid-type cooling towers, the technical development of which for large units being not yet guaranteed. (orig.) [de

  6. System and method for aligning heliostats of a solar power tower

    Science.gov (United States)

    Convery, Mark R.

    2013-01-01

    Disclosed is a solar power tower heliostat alignment system and method that includes a solar power tower with a focal area, a plurality of heliostats that each reflect sunlight towards the focal area of the solar power tower, an off-focal area location substantially close to the focal area of the solar power tower, a communication link between the off-focal area location and a misaligned heliostat, and a processor that interprets the communication between the off-focal area location and the misaligned heliostat to identify the misaligned heliostat from the plurality of heliostats and that determines a correction for the identified misaligned heliostat to realign the misaligned heliostat to reflect sunlight towards the focal area of the solar power tower.

  7. Fire behaviour of cooling tower packing; Brandverhalten von Kuehlturmeinbauten

    Energy Technology Data Exchange (ETDEWEB)

    Mattausch, Tim [DMT GmbH und Co. KG, Dortmund (Germany). Fachstelle fuer Brandschutz

    2013-10-01

    The rapid burning down of the cooling tower of the shutdown power plant in Schwandorf revealed the potential of a total loss of a cooling tower in case of fire. VGB ordered a research project in order to obtain more knowledge about the fire risk of cooling tower packing currently applied. Depending on kind and age of the plastics used, the results of these tests manifest a big variation of the fire behaviour. For the applications of plastics, it is essential to determine and to adhere to organisational fire protection measures. (orig.)

  8. Sicilian Castles and Coastal Towers

    Directory of Open Access Journals (Sweden)

    Kirk Scott

    2017-11-01

    Full Text Available While much attention has been paid to the development of castles as the hallmark architectural symbol of the Middle Ages, less attention has been given to the changes in European defensive strategies that occurred between the 15th and 17th centuries. It was at this time when the modern nations of Europe began to take form, as sea-based trade between distant nations took precedence over land-based trade routes. This paper examines how this transformation manifested in the defensive structures of Sicily, Italy, where the hilltop castles of the Middle Ages gradually gave way to a more cohesive network of coastal towers around the island. Putting this transition in its historical context, presenting an anthropological model from which to view this transition, and using geospatial methods to track these changes, the results of this study indicate that as defensive towers began to dominate the Sicilian coast around the 16th century, their command over the environment was no greater than that of the feudal castles which were still in use. Yet, unlike the castles of feudal lords, these towers represented an island-wide system of defense and the beginning of an adherence to a more centralized power structure then seen previously.

  9. A Dimensioning Methodology for a Natural Draft Wet Cooling Tower

    Directory of Open Access Journals (Sweden)

    Ioana Opriș

    2017-05-01

    Full Text Available The paper proposes a methodology for the dimensioning of a natural draft wet cooling tower. The main geometrical dimensions depend on the packing type, the cooling and the weather conditions. The study is based on splitting the tower in three main zones: the spray and packing zone, the rain zone and the natural draft zone. The methodology is developed on modular bases, by using block-modules both for the three main zones of the cooling tower and for the inlet/outlet air properties. It is useful in explaining to the students the complex physical phenomena within the cooling tower but also for the development of a computer program to be used in engineering, management and education.

  10. Research on Condition Assessment Method of Transmission Tower Under the Action of Strong Wind

    Science.gov (United States)

    Huang, Ren-mou; An, Li-qiang; Zhang, Rong-lun; Wu, Jiong; Liang, Ya-feng

    2018-03-01

    Transmission towers are often subjected to the external damage of severe weather like strong wind and so on, which may cause the collapse due to the yield and fracture of the tower material. Aiming this issue, an assessment method was proposed in this paper to assess the operation condition of transmission towers under strong wind. With a reasonable assess index system established firstly, then the internal force of the tower material was solved and its stability was determined through the mechanical analysis of the transmission tower finite element model. Meanwhile, the condition risk level of the tower was finally determined by considering the difference among the influences of other factors like corrosion and loose of members, slope on the transmission tower through the analytic hierarchy process. The assessment method was applied to assess the wind-induced collapse of towers in 110kV Bao Yi II line in Wenchang City, Hainan Province, of which the result proves the method can assess the condition of transmission tower under strong wind and of guiding significance for improving the windproof capability of transmission towers.

  11. A new tower with good p-rank meeting Zink’s bound

    DEFF Research Database (Denmark)

    Anbar Meidl, Nurdagül; Beelen, Peter; Nguyen, Nhut

    2017-01-01

    In this article we investigate the asymptotic p-rank of a new tower of function fields defined over cubic finite fields. Its limit meets Zink's bound, but the new feature of this tower is that its asymptotic p-rank for small cubic finite fields is much smaller than that of other cubic towers...

  12. One-year dynamic monitoring of a masonry tower

    Directory of Open Access Journals (Sweden)

    Guidobaldi Marco

    2015-01-01

    Full Text Available The paper presents some results of the continuous dynamic monitoring program carried out on the tallest historic tower in Mantua, Italy. This project follows an extensive diagnostic investigation aimed at assessing the structural condition of the tower after the Italian earthquakes of May 2012. A simple dynamic monitoring system was permanently installed in the upper part of the building and automatic modal identification was performed. The results allow to evaluate the effects of changing temperature on automatically identified natural frequencies, to verify the practical feasibility of damage detection methods based on natural frequencies shifts and provide clear evidence of the possible key role of continuous dynamic monitoring in the preventive conservation of historic towers.

  13. Study of water masses variability in the Mediterranean Sea using in-situ data / NEMO-Med12 model.

    Science.gov (United States)

    Margirier, Félix; Testor, Pierre; Mortier, Laurent; Arsouze, Thomas; Bosse, Anthony; Houpert, Loic; Hayes, Dan

    2016-04-01

    In the past 10 years, numerous observation programs in the Mediterranean deployed autonomous platforms (moorings, argo floats, gliders) and thus considerably increased the number of in-situ observations and the data coverage. In this study, we analyse time series built with profile data on interannual scales. Sorting data in regional boxes, we follow the evolution of different water masses in the basin and generate indexes to characterize their evolution. We then put those indexes in relation with external (atmospheric) forcings and present an intercomparison with the NEMO-Med12 model to estimate both the skill of the model and the relevance of the data-sampling in reproducing the evolution of water masses properties.

  14. Experimental evaluation of the wind effects on an operating power transmission tower

    Directory of Open Access Journals (Sweden)

    Hermes Carvalho

    Full Text Available Abstract Static and dynamic effects on power transmission towers can be evaluated by methodologies available in codes, which suggest the use of linear static analysis. By using numerical simulations, it is possible to observe the strong influence of the geometric nonlinear behavior of transmission cables. Dynamic effects also strongly influence this behavior, with the possibility of resonance between the cables and the structure, but up to the moment, the existent analysis procedures have not been completely validated on an experimental basis. In order to validate a complete analysis methodology, experimental procedures are proposed for a suspension tower of a 138kV transmission line in use. A tridimensional anemometer was installed on this structure in order to measure the values and directions of wind speeds. Simultaneous strain values were collected on the main elements of the tower through optical extensometers. Optical sensor technology with Fiber Bragg Gratings was used, due to the characteristic of immunity to the electromagnetic field occasioned by high electric currents. The string swing angle was evaluated through a high-resolution camera and a tridimensional accelerometer. With this instrumentation, it is possible to create a complete database that correlates wind speeds with the responses of the structural set. At the moment, 5 months of data have been collected and the instrumentation is in the final testing phase and synchronized. After this step, real-time measurements will be performed.

  15. Potentially pathogenic amoeba-associated microorganisms in cooling towers and their control.

    Science.gov (United States)

    Pagnier, Isabelle; Merchat, Michèle; La Scola, Bernard

    2009-06-01

    Cooling towers provide a favorable environment for the proliferation of microorganisms. Cooling towers generate a biofilm and often aerosolize contaminated water, thereby increasing the risk of microorganism dissemination by human inhalation. This pathogen dissemination was first revealed by the epidemics of Legionnaires' disease that were directly related to the presence of cooling towers, and since then, the ecology of Legionella pneumophila has been well studied. Each country has specific standards regarding the acceptable amount of microorganisms in cooling tower systems. However, those standards typically only concern L. pneumophila, even though many other microorganisms can also be isolated from cooling towers, including protozoa, bacteria and viruses. Microbiological control of the cooling tower system can be principally achieved by chemical treatments and also by improving the system's construction. Several new treatments are being studied to improve the efficiency of disinfection. However, as most of these treatments continue to focus solely on L. pneumophila, reports of other types of pathogens continue to increase. Therefore, how their dissemination affects the human populous health should be addressed now.

  16. Industrial cooling tower design and operation in the moderate-continental climate conditions

    OpenAIRE

    Laković Mirjana S.; Banjac Miloš J.; Laković Slobodan V.; Jović Milica M.

    2016-01-01

    A large number of producers offer a wide choice of various types of industrial cooling towers. Usually, a proper choice of pre-fabricated cooling tower satisfies end-user needs. However, if there are specific end-user requirements, it is necessary to design cooling tower according to those requirements. For the adhesive factory located in southern region of Serbia, 350 kW mechanical draught wet cooling tower was designed and built. Dimensioning of the cooli...

  17. Natural-draught cooling tower of the Philippsburg-1 reactor

    International Nuclear Information System (INIS)

    Ernst, G.; Wurz, D.

    1983-01-01

    In spring 1980 a comprehensive research programm was carried out on the natural-draught cooling tower of the Philippsburg-1 reactor. The study was meant to synchronously acquire all parameters necessary for the evaluation of plant operation and cooling tower emissions. The study is subdivided into 8 sub-projects. Parts 1 to 7 that are included in this progress-of-work report describe experimental work and discuss the results. A critical analysis of measuring results proves that the values for operational behaviour and cooling tower emissions were duly anticipated. Even a very critical judgment of the results can exclude direct or indirect hazards for humans, animals and plants owing to cooling tower emissions. Sub-project 8 compares results from diffusion calculations (24 models) to results gained from experiments. The results of sub-project 8 will be published in a progress report to come. (orig.) [de

  18. Recent developments using TowerJazz SiGe BiCMOS platform for mmWave and THz applications

    Science.gov (United States)

    Kar-Roy, Arjun; Howard, David; Preisler, Edward J.; Racanelli, Marco

    2013-05-01

    In this paper, we report on the highest speed 240GHz/340GHz FT/FMAX NPN which is now available for product designs in the SBC18H4 process variant of TowerJazz's mature 0.18μm SBC18 silicon germanium (SiGe) BiCMOS technology platform. NFMIN of ~2dB at 50GHz has been obtained with these NPNs. We also describe the integration of earlier generation NPNs with FT/FMAX of 240GHz/280GHz into SBC13H3, a 0.13μm SiGe BiCMOS technology platform. Next, we detail the integration of the deep silicon via (DSV), through silicon via (TSV), high-resistivity substrate, sub-field stitching and hybrid-stitching capability into the 0.18μm SBC18 technology platform to enable higher performance and highly integrated product designs. The integration of SBC18H3 into a thick-film SOI substrate, with essentially unchanged FT and FMAX, is also described. We also report on recent circuit demonstrations using the SBC18H3 platform: (1) a 4-element phased-array 70-100GHz broadband transmit and receive chip with flat saturated power greater than 5dBm and conversion gain of 33dB; (2) a fully integrated W-band 9-element phase-controllable array with responsivity of 800MV/W and receiver NETD is 0.45K with 20ms integration time; (3) a 16-element 4x4 phased-array transmitter with scanning in both the E- and H-planes with maximum EIRP of 23-25 dBm at 100-110GHz; (4) a power efficient 200GHz VCO with -7.25dBm output power and tuning range of 3.5%; and (5) a 320GHz 16-element imaging receiver array with responsivity of 18KV/W at 315GHz, a 3dB bandwidth of 25GHz and a low NEP of 34pW/Hz1/2. Wafer-scale large-die implementation of the phased-arrays and mmWave imagers using stitching in TowerJazz SBC18 process are also discussed.

  19. Longitudinal Seismic Behavior of a Single-Tower Cable-Stayed Bridge Subjected to Near-Field Earthquakes

    Directory of Open Access Journals (Sweden)

    J. Yi

    2017-01-01

    Full Text Available Cable-stayed bridges are quite sensitive to large amplitude oscillations from earthquakes and seismic damage was observed for Shipshaw Bridge and Chi-Lu Bridge during past earthquakes. In order to investigate seismic damage of cable-stayed bridges, a 1 : 20 scale model of a single-tower cable-stayed bridge with A-shaped tower was designed, constructed, and tested on shake tables at Tongji University, China. One typical near-field ground motion was used to excite the model from low to high intensity. Test result showed that severe structural damage occurred at the tower of the model including parallel concrete cracks from bottom to nearly half height of the tower, concrete spalling, and exposed bars at top tower 0.2 m above the section where two skewed legs intersect. Posttest analysis was conducted and compared with test results. It is revealed that the numerical model was able to simulate the seismic damage of the test model by modeling nonlinearity of different components for cable-stayed bridges, namely, the tower, bents, superstructure, cables, and bearings. Numerical analysis also revealed that cable relaxation, which was detected during the test, had limited influence on the overall seismic response of the bridge with maximum error of 12%.

  20. Research into spectra transformation of cooling tower droplet drift

    International Nuclear Information System (INIS)

    Mandrykin, G.P.

    1990-01-01

    Empirical droplet-diameter distributions in a cooling tower and outside are well approximated by the Rosin-Rammler-Bennet two-parameter function. Fractional efficiency of eliminators is also approximated by the above function fairly well. The design formulas proposed are universal and allow evaluation of droplet spectra transformation as well as the efficiency of measures for preventing droplet emissions from cooling towers both at the design and operation stages. Estimates of cooling tower droplet emissions calculated by the formulas suggested may be recommended as input data applied to the solution of environmental pollution problems and their assessment

  1. Productivity and CO2 exchange of Great Plains ecoregions. I. Shortgrass steppe: Flux tower estimates

    Science.gov (United States)

    Gilmanov, Tagir G.; Morgan, Jack A.; Hanan, Niall P.; Wylie, Bruce K.; Rajan, Nithya; Smith, David P.; Howard, Daniel M.

    2017-01-01

    The shortgrass steppe (SGS) occupies the southwestern part of the Great Plains. Half of the land is cultivated, but significant areas remain under natural vegetation. Despite previous studies of the SGS carbon cycle, not all aspects have been completely addressed, including gross productivity, ecosystem respiration, and ecophysiological parameters. Our analysis of 1998 − 2007 flux tower measurements at five Bowen ratio–energy balance (BREB) and three eddy covariance (EC) sites characterized seasonal and interannual variability of gross photosynthesis and ecosystem respiration. Identification of the nonrectangular hyperbolic equation for the diurnal CO2 exchange, with vapor pressure deficit (VPD) limitation and exponential temperature response, quantified quantum yield α, photosynthetic capacity Amax, and respiration rate rd with variation ranges (19 \\production from − 900 to + 700 g CO2 m− 2 yr− 1, indicating that SGS may switch from a sink to a source depending on weather. Comparison of the 2004 − 2006 measurements at two BREB and two parallel EC flux towers located at comparable SGS sites showed moderately higher photosynthesis, lower respiration, and higher net production at the BREB than EC sites. However, the difference was not related only to methodologies, as the normalized difference vegetation index at the BREB sites was higher than at the EC sites. Overall magnitudes and seasonal patterns at the BREB and the EC sites during the 3-yr period were similar, with trajectories within the ± 1.5 standard deviation around the mean of the four sites and mostly reflecting the effects of meteorology.

  2. Investigation on Shielding Failure of a Novel 400 kV Composite tower

    DEFF Research Database (Denmark)

    Wang, Qian; Jahangiri, Tohid; Bak, Claus Leth

    2018-01-01

    In this paper, the lightning shielding performance of a newly-designed 400 kV double-circuit composite tower is investigated. Based on a revised EGM method, traditional shielding failure regions, located at both sides of a traditional tower is no longer a big issue for the fully composite tower......, due to its unusual ‘Y’ configuration. Instead, a new unprotected region exists in the tower center. The maximum lightning current that can lead to shielding failure and the shielding failure rate (SFR) of the new tower are calculated. To verify results from the revised EGM method, a scale model test...... is conducted. Spatial shielding failure probability around the tower is calculated based on ratio of discharge paths recorded in the test. Moreover, based on test results, the maximum shielding failure lightning currents are obtained. Analysis and results derived from the revised EGM method and scale model...

  3. Towards safe and economic seismic design of cooling towers of extreme height

    International Nuclear Information System (INIS)

    Kraetzig, W.B.; Meskouris, K.

    1979-01-01

    Nuclear power plants are being increasingly equipped with natural draught cooling towers of heights greater than 160 m. In many arid zones, where high natural draught cooling towers with dry cooling systems are being projected, wind loads are relativelly small while site seismicity is relatively high. Thus the ability of the tower to withstand earthquake induced forces governs its design. On the other hand, most reinforced concrete cooling towers of extreme height built so far were designed to withstand high wind loads and moderate earthquake loads. The effects of special structural measures for obtaining an economic design, such as the introduction of ring stiffened shells, have been studied mainly for those towers. In view of the previous aspects it is the purpose of this paper to analyze the effects of various structural measures and other parameters on the seismic response of such high cooling towers. (orig.)

  4. Mathematical model and calculation of water-cooling efficiency in a film-filled cooling tower

    Science.gov (United States)

    Laptev, A. G.; Lapteva, E. A.

    2016-10-01

    Different approaches to simulation of momentum, mass, and energy transfer in packed beds are considered. The mathematical model of heat and mass transfer in a wetted packed bed for turbulent gas flow and laminar wave counter flow of the fluid film in sprinkler units of a water-cooling tower is presented. The packed bed is represented as the set of equivalent channels with correction to twisting. The idea put forward by P. Kapitsa on representation of waves on the interphase film surface as elements of the surface roughness in interaction with the gas flow is used. The temperature and moisture content profiles are found from the solution of differential equations of heat and mass transfer written for the equivalent channel with the volume heat and mass source. The equations for calculation of the average coefficients of heat emission and mass exchange in regular and irregular beds with different contact elements, as well as the expression for calculation of the average turbulent exchange coefficient are presented. The given formulas determine these coefficients for the known hydraulic resistance of the packed bed element. The results of solution of the system of equations are presented, and the water temperature profiles are shown for different sprinkler units in industrial water-cooling towers. The comparison with experimental data on thermal efficiency of the cooling tower is made; this allows one to determine the temperature of the cooled water at the output. The technical solutions on increasing the cooling tower performance by equalization of the air velocity profile at the input and creation of an additional phase contact region using irregular elements "Inzhekhim" are considered.

  5. Constraints on Nitrous Oxide emissions within the US Corn Belt using tall tower observations and an Eulerian Modeling Approach

    Science.gov (United States)

    Chen, Z.; Griffis, T. J.; Lee, X.; Fu, C.; Dlugokencky, E. J.; Andrews, A. E.

    2017-12-01

    Mitigation of nitrous oxide (N2O) emissions requires a sound understanding of N2O production processes and a robust estimate of N2O budgets. It is critical to understand how emissions vary spatially and temporally, and how they are likely to change given future climate and land management decisions. To address these challenges we have coupled two models including WRF-Chem version 3.8.1 and CLM-GBC-CROP version 4.5 to simulate retrospective and future N2O emissions for the US Corn Belt. Using 7 years (2010-2016) of N2O mixing ratio data from 6 tall tower sites within the US Midwest, we ran the coupled model at a spatial resolution of 0.125o× 0.125o and tested and optimized the simulation of N2O emissions at hourly, seasonal, and inter-annual timescales. Our preliminary results indicate:1) The simulated tall tower mixing ratios for 6 tall towers were all significantly higher than the observations in the growing seasons, indicating a high bias of N2O emissions when using the default N2O production mechanisms in CLM. 2) Following the optimization of N2O production in CLM, the simulated tall tower mixing ratios were strongly correlated with the KCMP and WBI towers, and had moderate correlation with the BAO tower. Overall, the absolute biases in mixing ratios were relatively small. Our next step is to examine 7 years of simulations to assess the spatiotemporal variations of direct and indirect emissions within the US Corn Belt to help identify potential N2O hotspots and hot moments.

  6. Statistical multi-model approach for performance assessment of cooling tower

    International Nuclear Information System (INIS)

    Pan, Tian-Hong; Shieh, Shyan-Shu; Jang, Shi-Shang; Tseng, Wen-Hung; Wu, Chan-Wei; Ou, Jenq-Jang

    2011-01-01

    This paper presents a data-driven model-based assessment strategy to investigate the performance of a cooling tower. In order to achieve this objective, the operations of a cooling tower are first characterized using a data-driven method, multiple models, which presents a set of local models in the format of linear equations. Satisfactory fuzzy c-mean clustering algorithm is used to classify operating data into several groups to build local models. The developed models are then applied to predict the performance of the system based on design input parameters provided by the manufacturer. The tower characteristics are also investigated using the proposed models via the effects of the water/air flow ratio. The predicted results tend to agree well with the calculated tower characteristics using actual measured operating data from an industrial plant. By comparison with the design characteristic curve provided by the manufacturer, the effectiveness of cooling tower can be obtained in the end. A case study conducted in a commercial plant demonstrates the validity of proposed approach. It should be noted that this is the first attempt to assess the cooling efficiency which is deviated from the original design value using operating data for an industrial scale process. Moreover, the evaluated process need not interrupt the normal operation of the cooling tower. This should be of particular interest in industrial applications.

  7. Probabilistic Capacity Assessment of Lattice Transmission Towers under Strong Wind

    Directory of Open Access Journals (Sweden)

    Wei eZhang

    2015-10-01

    Full Text Available Serving as one key component of the most important lifeline infrastructure system, transmission towers are vulnerable to multiple nature hazards including strong wind and could pose severe threats to the power system security with possible blackouts under extreme weather conditions, such as hurricanes, derechoes, or winter storms. For the security and resiliency of the power system, it is important to ensure the structural safety with enough capacity for all possible failure modes, such as structural stability. The study is to develop a probabilistic capacity assessment approach for transmission towers under strong wind loads. Due to the complicated structural details of lattice transmission towers, wind tunnel experiments are carried out to understand the complex interactions of wind and the lattice sections of transmission tower and drag coefficients and the dynamic amplification factor for different panels of the transmission tower are obtained. The wind profile is generated and the wind time histories are simulated as a summation of time-varying mean and fluctuating components. The capacity curve for the transmission towers is obtained from the incremental dynamic analysis (IDA method. To consider the stochastic nature of wind field, probabilistic capacity curves are generated by implementing IDA analysis for different wind yaw angles and different randomly generated wind speed time histories. After building the limit state functions based on the maximum allowable drift to height ratio, the probabilities of failure are obtained based on the meteorological data at a given site. As the transmission tower serves as the key nodes for the power network, the probabilistic capacity curves can be incorporated into the performance based design of the power transmission network.

  8. Siting Background Towers to Characterize Incoming Air for Urban Greenhouse Gas Estimation: A Case Study in the Washington, DC/Baltimore Area

    Science.gov (United States)

    Mueller, K.; Yadav, V.; Lopez-Coto, I.; Karion, A.; Gourdji, S.; Martin, C.; Whetstone, J.

    2018-03-01

    There is increased interest in understanding urban greenhouse gas (GHG) emissions. To accurately estimate city emissions, the influence of extraurban fluxes must first be removed from urban greenhouse gas (GHG) observations. This is especially true for regions, such as the U.S. Northeastern Corridor-Baltimore/Washington, DC (NEC-B/W), downwind of large fluxes. To help site background towers for the NEC-B/W, we use a coupled Bayesian Information Criteria and geostatistical regression approach to help site four background locations that best explain CO2 variability due to extraurban fluxes modeled at 12 urban towers. The synthetic experiment uses an atmospheric transport and dispersion model coupled with two different flux inventories to create modeled observations and evaluate 15 candidate towers located along the urban domain for February and July 2013. The analysis shows that the average ratios of extraurban inflow to total modeled enhancements at urban towers are 21% to 36% in February and 31% to 43% in July. In July, the incoming air dominates the total variability of synthetic enhancements at the urban towers (R2 = 0.58). Modeled observations from the selected background towers generally capture the variability in the synthetic CO2 enhancements at urban towers (R2 = 0.75, root-mean-square error (RMSE) = 3.64 ppm; R2 = 0.43, RMSE = 4.96 ppm for February and July). However, errors associated with representing background air can be up to 10 ppm for any given observation even with an optimal background tower configuration. More sophisticated methods may be necessary to represent background air to accurately estimate urban GHG emissions.

  9. Wind-induced transmission tower foundation loads. A field study-design code comparison

    Energy Technology Data Exchange (ETDEWEB)

    Savory, E. [Department of Mechanical and Materials Engineering, University of Western Ontario, London, Ont. (Canada); Parke, G.A.R.; Disney, P.; Toy, N. [School of Engineering, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

    2008-06-15

    This paper presents a comparison between the wind-induced foundation loads measured on a type L6 transmission line tower during a field study in the UK and those computed using the UK Code of Practice for lattice tower and transmission line design (BS8100). In this work, the Code provisions have been generalised to give the wind-induced strain in each of the tower legs immediately above the foundation as a function of wind direction and wind speed at the top of the tower. The complete data set from the field monitoring has been decomposed to provide a similar formulation for comparison purposes. The analysis shows excellent agreement between the Code calculations and the measured results, within the overall accuracy of the field data. This indicates that, at least for the tower type examined here, the existing design Code provides a reliable transformation of the local wind speed at the top of the tower into tension and compression loads on the foundations. (author)

  10. Easy steel tower elevation. Development of a steel tower elevating aiding device; Tetto shoko wo rakuraku to. Tetto shoko hojo sochi no kaihatsu ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Tobe, Y. [Kansai Electric Power Co. Inc., Osaka (Japan)

    1999-02-10

    Elevation of a transmission line steel tower is performed by an operator`s own force upon fixing a safety device to prevent a fall on a safety wire (SW) previously installed on a specified tower leg. It is a considerable burden for the operator to move the tower having a height of 80 to 100 m up and down several times a day. In order to reduce the fatigue, a portable, small and light-weight steel tower elevation aiding device was developed. The existing SW is used to fix the device, requiring no additional facility to be fixed on the tower. Safety assurance depends on the safety device on the SW as currently used. The device has pulling force of 50 kgf (the device operates in a range of 4 to 50 kgf to assure workability in elevation and stopping), and elevation speed of 15 to 20 m/minute (equivalent to the present work. The braking force can be adjusted in three steps at descent according to the ability of the operator). An Ni-hydrogen battery is used, capable of two returns on a tower per charge. Considering the device to be transported in mountainous area, the shape is such that a single unit can be put into a backpack. The device can also be used in general construction sites. (NEDO)

  11. Active tower damping and pitch balancing - design, simulation and field test

    Science.gov (United States)

    Duckwitz, Daniel; Shan, Martin

    2014-12-01

    The tower is one of the major components in wind turbines with a contribution to the cost of energy of 8 to 12% [1]. In this overview the load situation of the tower will be described in terms of sources of loads, load components and fatigue contribution. Then two load reduction control schemes are described along with simulation and field test results. Pitch Balancing is described as a method to reduce aerodynamic asymmetry and the resulting fatigue loads. Active Tower Damping is reducing the tower oscillations by applying appropiate pitch angle changes. A field test was conducted on an Areva M5000 wind turbine.

  12. Detection of Excessive Wind Turbine Tower Oscillations Fore-Aft and Sideways

    DEFF Research Database (Denmark)

    Knudsen, Torben; Bak, Thomas; Tabatabaeipour, Seyed Mojtaba

    2012-01-01

    Fatigue loads are important for the overall cost of energy from a wind turbine. Loading on the tower is one of the more important loads, as the tower is an expensive component. Consequently, it is important to detect tower loads, which are larger than necessary. This paper deals with both fore......-aft and sideways tower oscillations. Methods for estimation of the amplitude and detection of the cause for vibrations are developed. Good results are demonstrated for real data from modern multi mega watt turbines. It is shown that large oscillations can be detected and that the method can discriminate between...... wind turbulence and unbalanced rotor....

  13. Cooling tower water conditioning study. [using ozone

    Science.gov (United States)

    Humphrey, M. F.; French, K. R.

    1979-01-01

    Successful elimination of cooling tower treatment chemicals was demonstrated. Three towers functioned for long periods of time with ozone as the only treatment for the water. The water in the systems was reused as much as 30 times (cycles of concentration) without deleterious effects to the heat exchangers. Actual system blow-down was eliminated and the only makeup water added was that required to replace the evaporation and mist entrainment losses. Minimum water savings alone are approximately 75.1 1/kg/year. Cost estimates indicate that a savings of 55 percent was obtained on the systems using ozone. A major problem experienced in the use of ozone for cooling tower applications was the difficulty of accurate concentration measurements. The ability to control the operational characteristics relies on easily and accurately determined concentration levels. Present methods of detection are subject to inaccuracies because of interfering materials and the rapid destruction of the ozone.

  14. Fatigue Analysis of a Mono-Tower Platform

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Sørensen, John Dalsgaard; Brincker, Rune

    In this paper, a fatigue reliability analysis of a Mono-tower platform is presented. The failure mode, fatigue failure in the butt welds, is investigated with two different models. The one with the fatigue strength expressed through SN relations, the other with the fatigue strength expressed thro...... of the natural period, damping ratio, current, stress Spectrum and parameters describing the fatigue strength. Further, soil damping is shown to be significant for the Mono-tower.......In this paper, a fatigue reliability analysis of a Mono-tower platform is presented. The failure mode, fatigue failure in the butt welds, is investigated with two different models. The one with the fatigue strength expressed through SN relations, the other with the fatigue strength expressed...... through linear-elastic fracture mechanics (LEFM). In determining the cumulative fatigue damage, Palmgren-Miner's rule is applied. Element reliability as well as systems reliability is estimated using first-order reliability methods (FORM). The sensitivity of the systems reliability to various parameters...

  15. Operating manual for the Tower Shielding Facility

    International Nuclear Information System (INIS)

    1985-12-01

    This manual provides information necessary to operate and perform maintenance on the reactor systems and all equipment or systems which can affect their operation or the safety of personnel at the Tower Shielding Facility. The first four chapters consist of introductory and descriptive material of benefit to personnel in training, the qualifications required for training, the responsibilities of the personnel in the organization, and the procedures for reviewing proposed experiments. Chapter 8, Emergency Procedures, is also a necessary part of the indoctrination of personnel. The procedures for operation of the Tower Shielding Reactor (TSR-II), its water cooling system, and the main tower hoists are outlined in Chapters 5, 6, and 7. The Technical Specification surveillance requirements for the TSR-II are summarized in Chapter 9. The maintenance and calibration schedule is spelled out in Chapter 10. The procedures for assembly and disassembly of the TSR-II are outlined in Chapter 11

  16. The solar two power tower project

    International Nuclear Information System (INIS)

    Chavez, J.M.; Klimas, P.C.; Laquil, P. de III; Skowronski, M.

    1993-01-01

    A consortium of United States utility concerns led by Southern California Edison Company (SCE) has begun a cooperative project with the U.S. Department of Energy (DOE) and industry to convert the 10-MWe Solar One Tower Pilot Plant to molten nitrate salt technology. Successful operation of the convert plant to be called Solar Two, will reduce the economic risks in building the initial commercial power tower projects and accelerate the commercial acceptance of this promising renewable energy technology. In a molten salt power tower plant, sunlight is concentrated by a field of sun-tracking mirrors, called heliostats, onto a centrally located receiver, atop a tower. Molten salt is heated in the receiver and stored until it is needed to generate steam to power a conventional turbine generator. Joining the SCE and DOE in sponsoring in sponsoring this project are the following organizations: Los Alamos department of Water Power, Idaho Power Company, PacifiCorp, Pacific Gas and Electric Company, Sacramento Municipal Utility District, Arizona Public Service Company, Salt River Project, City of Pasadena, California Energy Commission, Electric Power Research Institute, South Coast Air Quality Commission, Electric Power research Institute, South Coast Air Quality Management District, and Bechtel Corporation. The Solar Two project will convert the Solar One heat transfer system from a water/steam type to molten nitrate salt by replacing the water/steam receiver and oil/rock thermal storage system with a nitrate salt receiver, salt thermal storage, and steam generator. The estimate cost of Solar Two, including 3-year test period, is 48.5 millions. The plant will be on line in early 1995. (authors)

  17. On the possibility of a ''dry'' cooling tower application for the APS condensators with a dissociating coolant

    International Nuclear Information System (INIS)

    Mikhalevich, A.A.; Nesterenko, V.B.; Peslyak, V.I.

    1975-01-01

    Calculations have been carried out for a Geller cooling tower of a 1000 MW nuclear power plant aimed at investigating the possibility of using ''dry'' cooling towers to cool condensers of nuclear power plants with N 2 O 4 as coolant, and at estimating specific charges on the process water supply system. Taking into consideration commercialy produced equipment, air condenser plants are assumed to operate with an ordinary surface condenser. The main dimensional and cost parameters of a ''dry'' cooling tower for a thermal cycle version with the maximum temperature of 450 deg C are calculated using the Transelectro (Hungary) nomograms for average annual air temperature. The calculation results show the Geller cooling towers for 1000 MW nuclear power plants to be economically competitive with evaporating cooling towers; and more; besides, is this case atmosphere pollution is avoided and water flow rate for making-up the water supply system is reduced

  18. Virtual and remote control tower research, design, development and validation

    CERN Document Server

    2016-01-01

    The interdisciplinary research and development work carried out in the last ten years which is presented in this book aimed at replacing the conventional airport control tower by a new “remote tower operation” work environment (RTO) which should enhance work efficiency and safety and reduce costs. This revolutionary human–system interface allows for remote aerodrome traffic control without a physical tower building and enables the establishment of remote airport traffic control centers (RTC) of which each may serve several airports from a central location.

  19. Sensor Placement For Structural Monitoring of Transmission Line Towers

    Directory of Open Access Journals (Sweden)

    Benny eRaphael

    2015-11-01

    Full Text Available Transmission line towers are usually analyzed using linear elastic idealized truss models. Due to the assumptions used in the analysis, there are discrepancies between the actual results obtained from full scale prototype testing and the analytical results. Therefore, design engineers are interested in assessing the actual stress levels in transmission line towers. Since it is costly to place sensors on every member of a tower structure, the best locations for sensors need to be carefully selected. This study evaluates a methodology for sensor placement in transmission line towers. The objective is to find optimal locations for sensors such that the real behavior of the structure can be explained from measurements. The methodology is based on the concepts of entropy and model falsification. Sensor locations are selected based on maximum entropy such that there is maximum separation between model instances that represent different possible combinations of parameter values which have uncertainties. The performance of the proposed algorithm is compared to that of an intuitive method in which sensor locations are selected where the forces are maximum. A typical 220 kV transmission tower is taken as case study in this paper. It is shown that the intuitive method results in much higher number of non-separable models compared to the optimal sensor placement algorithm. Thus the intuitive method results in poor identification of the system.

  20. Comparative study of sea ice dynamics simulations with a Maxwell elasto-brittle rheology and the elastic-viscous-plastic rheology in NEMO-LIM3

    Science.gov (United States)

    Raulier, Jonathan; Dansereau, Véronique; Fichefet, Thierry; Legat, Vincent; Weiss, Jérôme

    2017-04-01

    Sea ice is a highly dynamical environment characterized by a dense mesh of fractures or leads, constantly opening and closing over short time scales. This characteristic geomorphology is linked to the existence of linear kinematic features, which consist of quasi-linear patterns emerging from the observed strain rate field of sea ice. Standard rheologies used in most state-of-the-art sea ice models, like the well-known elastic-viscous-plastic rheology, are thought to misrepresent those linear kinematic features and the observed statistical distribution of deformation rates. Dedicated rheologies built to catch the processes known to be at the origin of the formation of leads are developed but still need evaluations on the global scale. One of them, based on a Maxwell elasto-brittle formulation, is being integrated in the NEMO-LIM3 global ocean-sea ice model (www.nemo-ocean.eu; www.elic.ucl.ac.be/lim). In the present study, we compare the results of the sea ice model LIM3 obtained with two different rheologies: the elastic-viscous-plastic rheology commonly used in LIM3 and a Maxwell elasto-brittle rheology. This comparison is focused on the statistical characteristics of the simulated deformation rate and on the ability of the model to reproduce the existence of leads within the ice pack. The impact of the lead representation on fluxes between ice, atmosphere and ocean is also assessed.

  1. Towers of the new 380 kV high-voltage overhead line across the Elbe

    Energy Technology Data Exchange (ETDEWEB)

    Kiessling, F; Sperl, H D; Wagemann, F

    1979-11-01

    As part of the European power transmission line between North Sweden and Southern Italy, a 380 kV rotary-current overhead line crosses the Elbe river south of Hamburg. To achieve the overhead clearance of 80 m required for navigation and the maximum line sag of 85 m, two steel trelliswork towers were constructed about 1200 m apart, each of them 227 m high. The 12 phases (cables) of the line are suspended each on three horizontal beams at a horizontal distance of 16 m. Exceptional loads far beyond the standards set in VDE 0210/5.69 have been assumed for the layout. In the case of the wind loads the frequent gales had to be considered; for ice loads, class I of the IEC/TC 11 Draft on Ice loading on Overhead Lines . Amsterdam 1977, was assumed. Some further loads are described as well as the tender procedure, supply and assembly of the towers.

  2. Cell Towers and Songbirds

    Science.gov (United States)

    Klosterman, Michelle; Mesa, Jennifer; Milton, Katie

    2009-01-01

    This article describes how our common addiction to cell phones was used to launch a discussion about their use, impacts on the environment, and connections to issues of civic concern. By encouraging middle school science students to adopt the perspectives of special-interest groups debating communication tower restrictions designed to protect…

  3. Disinfection of bacterial biofilms in pilot-scale cooling tower systems.

    Science.gov (United States)

    Liu, Yang; Zhang, Wei; Sileika, Tadas; Warta, Richard; Cianciotto, Nicholas P; Packman, Aaron I

    2011-04-01

    The impact of continuous chlorination and periodic glutaraldehyde treatment on planktonic and biofilm microbial communities was evaluated in pilot-scale cooling towers operated continuously for 3 months. The system was operated at a flow rate of 10,080 l day(-1). Experiments were performed with a well-defined microbial consortium containing three heterotrophic bacteria: Pseudomonas aeruginosa, Klebsiella pneumoniae and Flavobacterium sp. The persistence of each species was monitored in the recirculating cooling water loop and in biofilms on steel and PVC coupons in the cooling tower basin. The observed bacterial colonization in cooling towers did not follow trends in growth rates observed under batch conditions and, instead, reflected differences in the ability of each organism to remain attached and form biofilms under the high-through flow conditions in cooling towers. Flavobacterium was the dominant organism in the community, while P. aeruginosa and K. pneumoniae did not attach well to either PVC or steel coupons in cooling towers and were not able to persist in biofilms. As a result, the much greater ability of Flavobacterium to adhere to surfaces protected it from disinfection, whereas P. aeruginosa and K. pneumoniae were subject to rapid disinfection in the planktonic state.

  4. Improvement of coal focus and cooling towers of COFRENTES NPP

    International Nuclear Information System (INIS)

    Martinez, I.; Bogh, P.

    1998-01-01

    Cofrentes Nuclear Power Plant is performing a improving program of its cooling towers based on the filling revamping and cooling water circuit improvement. Furthermore, and as consequence of the acquired experience on cooling towers due to the mentioned program, Cofrentes NPP has decided to follow up with this project from a different point of view based on the thermal-hydraulic optimization of the cooling process inside the towers. This program, which is going to be carried out by Cofrentes NPP, Iberinco and Energy Planning and Power Generation (EPPG) provides an improvement on the thermal profile and of the draught inside the cooling towers by improving the water distribution in the towers active area. In order to perform such a program is needed to fulfill a test program to assure a guaranteed performance gain. In this way, Iberinco is developing a test procedure which improves the results which are obtained with the present standards used commonly by the industry. As a consequence of this program, Cofrentes is expecting to obtain a gain of 5 to 8 MWe with a revenue period of 4 to 5 months, results validated in another foreigner Plant which have developed a similar program. (Author)

  5. Removing Traffic Emissions from CO2 Time Series Measured at a Tall Tower Using on-Road Measurements and WRF-Stilt Transport Modeling

    Science.gov (United States)

    Schmidt, A.; Rella, C.; Goeckede, M.; Hanson, C. V.; Yang, Z.; Law, B. E.

    2014-12-01

    In recent years, measurements of atmospheric carbon dioxide with high precision and accuracy have become increasingly important for climate change research, in particular to inform terrestrial biosphere models. Anthropogenic carbon dioxide emissions from fossil fuel burning have long been recognized to contribute a significant portion of the carbon dioxide in the atmosphere. Here, we present an approach to remove the traffic related carbon dioxide emissions from mole fractions measured at a tall tower by using the corresponding carbon monoxide measurements in combination with footprint analyses and transport modeling. This technique improves the suitability of the CO2 data to be used in inverse modeling approaches of atmosphere-biosphere exchange that do not account for non-biotic portions of CO2. In our study region in Oregon, road traffic emissions are the biggest source of anthropogenic carbon dioxide and carbon monoxide. A three-day mobile campaign covering 1700 km of roads in northwestern Oregon was performed during summer of 2012 using a laser-based Cavity Ring Down Spectrometer. The mobile measurements incorporated different roads including main highways, urban streets, and back-roads, largely within the typical footprint of a tall CO2 observation tower in Oregon's Willamette Valley. For the first time, traffic related CO:CO2 emission ratios were measured directly at the sources during an on-road campaign under a variety of different driving conditions. An average emission ratio of 7.43 (±1.80) ppb CO per ppm CO2 was obtained for the study region and applied to separate the traffic related portion of CO2 from the mole fraction time series. The road traffic related portion of the CO2 mole fractions measured at the tower site reached maximum values from 9.8 to 12 ppm, depending on the height above the surface, during summer 2012.

  6. Design of SMART waste heat removal dry cooling tower using solar energy

    International Nuclear Information System (INIS)

    Choi, Yong Jae; Jeong, Yong Hoon

    2014-01-01

    The 85% of cooling system are once-through cooling system and closed cycle wet cooling system. However, many countries are trying to reduce the power plant water requirement due to the water shortage and water pollution. Dry cooling system is investigated for water saving advantage. There are two dry cooling system which are direct and indirect cooling system. In direct type, turbine exhaust is directly cooled by air-cooled condenser. In indirect system, turbine steam is cooled by recirculating intermediate cooling water loop, then the loop is cooled by air-cooled heat exchanger in cooling tower. In this paper, the purpose is to remove SMART waste heat, 200MW by using newly designed tower. The possibility of enhancing cooling performance by solar energy is analyzed. The simple cooling tower and solar energy cooling tower are presented and two design should meet the purpose of removing SMART waste heat, 200MW. In first design, when tower diameter is 70m, the height of tower should be 360m high. In second design, the chimney height decrease from 360m to 180m as collector radius increase from 100m to 500m due to collector temperature enhancement by solar energy, To analyze solar cooling tower further, consideration of solar energy performance at night should be analyzed

  7. Design of SMART waste heat removal dry cooling tower using solar energy

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yong Jae; Jeong, Yong Hoon [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-10-15

    The 85% of cooling system are once-through cooling system and closed cycle wet cooling system. However, many countries are trying to reduce the power plant water requirement due to the water shortage and water pollution. Dry cooling system is investigated for water saving advantage. There are two dry cooling system which are direct and indirect cooling system. In direct type, turbine exhaust is directly cooled by air-cooled condenser. In indirect system, turbine steam is cooled by recirculating intermediate cooling water loop, then the loop is cooled by air-cooled heat exchanger in cooling tower. In this paper, the purpose is to remove SMART waste heat, 200MW by using newly designed tower. The possibility of enhancing cooling performance by solar energy is analyzed. The simple cooling tower and solar energy cooling tower are presented and two design should meet the purpose of removing SMART waste heat, 200MW. In first design, when tower diameter is 70m, the height of tower should be 360m high. In second design, the chimney height decrease from 360m to 180m as collector radius increase from 100m to 500m due to collector temperature enhancement by solar energy, To analyze solar cooling tower further, consideration of solar energy performance at night should be analyzed.

  8. Allegheny County Cell Tower Points

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset portrays cell tower locations as points in Allegheny County. The dataset is based on outbuilding codes in the Property Assessment Parcel Database used...

  9. 45-FOOT HIGH DROP TOWER

    Data.gov (United States)

    Federal Laboratory Consortium — The Drop Tower is used to simulate and measure the impact shocks that are exerted on parachute loads when they hit the ground. It is also used for HSL static lift to...

  10. Modeling of existing cooling towers in ASPEN PLUS using an equilibrium stage method

    International Nuclear Information System (INIS)

    Queiroz, João A.; Rodrigues, Vitor M.S.; Matos, Henrique A.; Martins, F.G.

    2012-01-01

    Highlights: ► Simulation of cooling tower performance under different operating conditions. ► Cooling tower performance is simulated using ASPEN PLUS. ► Levenberg–Marquardt method used to adjust model parameters. ► Air and water outlet temperatures are in good accordance with experimental data. - Abstract: Simulation of cooling tower performance considering operating conditions away from design is typically based on the geometrical parameters provided by the cooling tower vendor, which are often unavailable or outdated. In this paper a different approach for cooling tower modeling based on equilibrium stages and Murphree efficiencies to describe heat and mass transfer is presented. This approach is validated with published data and with data collected from an industrial application. Cooling tower performance is simulated using ASPEN PLUS. Murphree stage efficiency values for the process simulator model were optimized by minimizing the squared difference between the experimental and calculated data using the Levenberg–Marquardt method. The minimization algorithm was implemented in Microsoft Excel with Visual Basic for Applications, integrated with the process simulator (ASPEN PLUS) using Aspen Simulation Workbook. The simulated cooling tower air and water outlet temperatures are in good accordance with experimental data when applying only the outlet water temperature to calibrate the model. The methodology is accurate for simulating cooling towers at different operational conditions.

  11. Reducing water consumption of an industrial plant cooling unit using hybrid cooling tower

    International Nuclear Information System (INIS)

    Rezaei, Ebrahim; Shafiei, Sirous; Abdollahnezhad, Aydin

    2010-01-01

    Water consumption is an important problem in dry zones and poor water supply areas. For these areas use of a combination of wet and dry cooling towers (hybrid cooling) has been suggested in order to reduce water consumption. In this work, wet and dry sections of a hybrid cooling tower for the estimation of water loss was modeled. A computer code was also written to simulate such hybrid cooling tower. To test the result of this simulation, a pilot hybrid tower containing a wet tower and 12 compact air cooled heat exchangers was designed and constructed. Pilot data were compared with simulation data and a correction factor was added to the simulation. Ensuring that the simulation represents the actual data, it was applied to a real industrial case and the effect of using a dry tower on water loss reduction of this plant cooling unit was investigated. Finally feasibility study was carried out to choose the best operating conditions for the hybrid cooling tower configuration proposed for this cooling unit.

  12. Improving Global Gross Primary Productivity Estimates by Computing Optimum Light Use Efficiencies Using Flux Tower Data

    Science.gov (United States)

    Madani, Nima; Kimball, John S.; Running, Steven W.

    2017-11-01

    In the light use efficiency (LUE) approach of estimating the gross primary productivity (GPP), plant productivity is linearly related to absorbed photosynthetically active radiation assuming that plants absorb and convert solar energy into biomass within a maximum LUE (LUEmax) rate, which is assumed to vary conservatively within a given biome type. However, it has been shown that photosynthetic efficiency can vary within biomes. In this study, we used 149 global CO2 flux towers to derive the optimum LUE (LUEopt) under prevailing climate conditions for each tower location, stratified according to model training and test sites. Unlike LUEmax, LUEopt varies according to heterogeneous landscape characteristics and species traits. The LUEopt data showed large spatial variability within and between biome types, so that a simple biome classification explained only 29% of LUEopt variability over 95 global tower training sites. The use of explanatory variables in a mixed effect regression model explained 62.2% of the spatial variability in tower LUEopt data. The resulting regression model was used for global extrapolation of the LUEopt data and GPP estimation. The GPP estimated using the new LUEopt map showed significant improvement relative to global tower data, including a 15% R2 increase and 34% root-mean-square error reduction relative to baseline GPP calculations derived from biome-specific LUEmax constants. The new global LUEopt map is expected to improve the performance of LUE-based GPP algorithms for better assessment and monitoring of global terrestrial productivity and carbon dynamics.

  13. Cellular Phone Towers, File name = CELLTOWERS Contains point file of cell towers and an inclomplete poly cadastral layer of properties with cell towers. http://www.harfordcountymd.gov/gis/Index.cfm, Published in 2011, 1:1200 (1in=100ft) scale, Harford County Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Cellular Phone Towers dataset current as of 2011. File name = CELLTOWERS Contains point file of cell towers and an inclomplete poly cadastral layer of properties...

  14. Role of bacterial adhesion in the microbial ecology of biofilms in cooling tower systems.

    Science.gov (United States)

    Liu, Yang; Zhang, Wei; Sileika, Tadas; Warta, Richard; Cianciotto, Nicholas P; Packman, Aaron

    2009-01-01

    The fate of the three heterotrophic biofilm forming bacteria, Pseudomonas aeruginosa, Klebsiella pneumoniae and Flavobacterium sp. in pilot scale cooling towers was evaluated both by observing the persistence of each species in the recirculating water and the formation of biofilms on steel coupons placed in each cooling tower water reservoir. Two different cooling tower experiments were performed: a short-term study (6 days) to observe the initial bacterial colonization of the cooling tower, and a long-term study (3 months) to observe the ecological dynamics with repeated introduction of the test strains. An additional set of batch experiments (6 days) was carried out to evaluate the adhesion of each strain to steel surfaces under similar conditions to those found in the cooling tower experiments. Substantial differences were observed in the microbial communities that developed in the batch systems and cooling towers. P. aeruginosa showed a low degree of adherence to steel surfaces both in batch and in the cooling towers, but grew much faster than K. pneumoniae and Flavobacterium in mixed-species biofilms and ultimately became the dominant organism in the closed batch systems. However, the low degree of adherence caused P. aeruginosa to be rapidly washed out of the open cooling tower systems, and Flavobacterium became the dominant microorganism in the cooling towers in both the short-term and long-term experiments. These results indicate that adhesion, retention and growth on solid surfaces play important roles in the bacterial community that develops in cooling tower systems.

  15. Trends, Opportunities, and Challenges for Tall Wind Turbine and Tower Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Lantz, Eric; Roberts, Owen; Dykes, Katherine

    2017-06-28

    This presentation summarizes recent analysis focused on characterizing the opportunity for Tall Wind technologies generally and for tall tower technologies specifically. It seeks to illuminate and explain the concept of Tall Wind, its impact on the wind industry to date, and the potential value of Tall Wind in the future. It also explores the conditions and locations under which the impacts of Tall Wind offer the most significant potential to increase wind technology performance. In addition, it seeks to examine the status of tall tower technology as a key sub-component of Tall Wind, focusing on the potential for continued innovation in tubular steel wind turbine towers and the status and potential for a select set of alternative tall tower technologies.

  16. Reducing the risk of Legionnaires' disease associated with cooling towers

    Energy Technology Data Exchange (ETDEWEB)

    Freije, M.R. [HC Information Resources Inc., Carlsbad, CA (United States)

    2008-08-15

    To reduce the health and legal risks associated with Legionnaires' disease, facility managers should take steps to minimize Legionella bacteria in plumbing systems, open industrial equipment, water features, cooling towers, and other aerosolizing water systems. The risk of Legionnaires' disease associated with cooling towers can be reduced by controlling Legionella bacteria in cooling water and preventing transmission of the bacteria from towers to people. This paper presents nine reasonable ways to accomplish these goals. (orig.)

  17. Fire analog: a comparison between fire plumes and energy center cooling tower plumes

    Energy Technology Data Exchange (ETDEWEB)

    Orgill, M.M.

    1977-10-01

    Thermal plumes or convection columns associated with large fires are compared to thermal plumes from cooling towers and proposed energy centers to evaluate the fire analog concept. Energy release rates of mass fires are generally larger than for single or small groups of cooling towers but are comparable to proposed large energy centers. However, significant physical differences exist between cooling tower plumes and fire plumes. Cooling tower plumes are generally dominated by ambient wind, stability and turbulence conditions. Fire plumes, depending on burning rates and other factors, can transform into convective columns which may cause the fire behavior to become more violent. This transformation can cause strong inflow winds and updrafts, turbulence and concentrated vortices. Intense convective columns may interact with ambient winds to create significant downwind effects such as wakes and Karman vortex streets. These characteristics have not been observed with cooling tower plumes to date. The differences in physical characteristics between cooling tower and fire plumes makes the fire analog concept very questionable even though the approximate energy requirements appear to be satisfied in case of large energy centers. Additional research is suggested in studying the upper-level plume characteristics of small experimental fires so this information can be correlated with similar data from cooling towers. Numerical simulation of fires and proposed multiple cooling tower systems could also provide comparative data.

  18. INTEGRATED TWIN TOWERS DAN ISLAMISASI ILMU

    Directory of Open Access Journals (Sweden)

    Syaifuddin Syaifuddin

    2013-05-01

    Full Text Available This paper shows some idea as follows: First, integrated design of the Twin Towers as the changing action from IAIN to UIN Sunan Ampel. The religion and general knowledge’s position of Twin Towers’ integrated design is not mixed into one, but it works individually, and at the certain time are united in mutual dialogue. Second, Islamize design is done in order to criticize the general knowledge which has western sources and are secular, materialistic, and individualistic. In the process to Islamize the knowledge, Islamic knowledge tries to intervene the general knowledge in order to filter it so the knowledge will be Islamized. Consequently, to Islamize knowledge is to give an Islamic concept into general knowledge. Third, there are the similarities and differences between integrated design knowledge based on Islamic knowledge and integrated Twin Towers. The difference is in its epistemology process. The similarity is in the curriculum (ontology and objective (axiology. In the curriculum, the examined knowledge is religion and general knowledge. While the objective, Islamize knowledge and integrated Twin Towers aims to integrate religion and general knowledge, to dialogue, to communicate, and to synergy, so it can be a knowledge which is intact-integral-integrative.

  19. Effect of heliostat size on the levelized cost of electricity for power towers

    Science.gov (United States)

    Pidaparthi, Arvind; Hoffmann, Jaap

    2017-06-01

    The objective of this study is to investigate the effects of heliostat size on the levelized cost of electricity (LCOE) for power tower plants. These effects are analyzed in a power tower with a net capacity of 100 MWe, 8 hours of thermal energy storage and a solar multiple of 1.8 in Upington, South Africa. A large, medium and a small size heliostat with a total area of 115.56 m2, 43.3 m2 and 15.67 m2 respectively are considered for comparison. A radial-staggered pattern and an external cylindrical receiver are considered for the heliostat field layouts. The optical performance of the optimized heliostat field layouts has been evaluated by the Hermite (analytical) method using SolarPILOT, a tool used for the generation and optimization of the heliostat field layout. The heliostat cost per unit is calculated separately for the three different heliostat sizes and the effects due to size scaling, learning curve benefits and the price index is included. The annual operation and maintenance (O&M) costs are estimated separately for the three heliostat fields, where the number of personnel required in the field is determined by the number of heliostats in the field. The LCOE values are used as a figure of merit to compare the different heliostat sizes. The results, which include the economic and the optical performance along with the annual O&M costs, indicate that lowest LCOE values are achieved by the medium size heliostat with an area of 43.3 m2 for this configuration. This study will help power tower developers determine the optimal heliostat size for power tower plants currently in the development stage.

  20. Kaiseraugst nuclear power station: meteorological effects of the cooling towers

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    Considerations of water conservation persuaded the German Government in 1971 not to allow the use of the Aar and Rhine for direct cooling of nuclear power stations. The criticism is often made that the Kaiseraugst cooling towers were built without full consideration of the resulting meteorological effects. The criticism is considered unjustified because the Federal Cooling Tower Commission considered all the relevant aspects before making its recommendations in 1972. Test results and other considerations show that the effect of the kaiseraugst cooling towers on meteorological and climatic conditions is indeed minimal and details are given. (P.G.R.)

  1. Seismic risk assessment of Trani's Cathedral bell tower in Apulia, Italy

    Science.gov (United States)

    Diaferio, Mariella; Foti, Dora

    2017-09-01

    The present paper deals with the evaluation of the seismic vulnerability of slender historical buildings; these structures, in fact, may manifest a high risk with respect to seismic actions as usually they have been designed to resist to gravitational loads only, and are characterized by a high flexibility. To evaluate this behavior, the bell tower of the Trani's Cathedral is investigated. The tower is 57 m tall and is characterized by an unusual building typology, i.e., the walls are composed of a concrete core coupled with external masonry stones. The dynamic parameters and the mechanical properties of the tower have been evaluated on the basis of an extensive experimental campaign that made use of ambient vibration tests and ground penetrating radar tests. Such data have been utilized to calibrate a numerical model of the examined tower. A linear static analysis, a dynamic analysis and a nonlinear static analysis have been carried out on such model to evaluate the displacement capacity of the tower and the seismic risk assessment in accordance with the Italian guidelines.

  2. Modification of the colony tower for the Rio Blanco detonation

    International Nuclear Information System (INIS)

    Blume, J.A.; Freeman, S.A.; Honda, K.K.; Lee, L.A.

    1975-01-01

    Supplemental structural bracing was designed and installed for the 180-ft-tall Colony Tower, an experimental oil shale processing retort structure, in anticipation of its lateral response to the Rio Blanco detonation. The tower is a steel structure with both horizontal and vertical diagonal bracing. Data obtained from the earlier Project Rulison detonation indicated that an evaluation study was necessary. Design criteria that would provide an adequate margin of safety were developed based on predicted Rio Blanco ground motion. The evaluation of the unmodified structure showed that several bracing members would be subjected to forces exceeding their yield strength, and some would reach a level at which failure could occur. Further analyses were made with assumed modified bracing members. A final scheme for modified vertical bracing was established and installed. After modification, the response of the tower during the Rio Blanco detonation was measured by instruments on the ground and at various locations on the tower, and no evidence of damage was discovered. The modification of the Colony Tower and the procedures used to determine these modifications show the usefulness of current ground motion and structural response prediction technology for forecasting dynamic behavior of important structures subjected to ground motion from underground nuclear explosions. (auth)

  3. De Reus van Schimmert : from a water tower to a green data center

    NARCIS (Netherlands)

    Tzanakakis, K.

    2017-01-01

    The water tower of Schimmert is an iconic tower that has served the local community for decades. In 2014 it was decommissioned and currently local companies and authorities are searching for a viable business model for this imposing tower. The present report examines the feasibility of transforming

  4. Experimental Investigation on Strengthening of Bolted Connections in Transmission/Communication Towers

    Science.gov (United States)

    Balagopal, R.; Prasad Rao, N.; Rokade, R. P.; Umesha, P. K.

    2018-02-01

    Due to increase in demand for power supply and increase in bandwidth for communication industry, the existing transmission line (TL) and communication towers needs to be strengthened. The strengthening of existing tower is economical rather than installation of new towers due to constraints in acquisition of land. The size of conductors have to be increased or additional number of antenna needs to be installed in existing TL/communication tower respectively. The compression and tension capacity of members in the existing towers have to be increased to sustain the additional loads due to wind and self-weight of these components. The tension capacity enhancement of existing angle sections in live line condition without power shut-down is a challenging task. In the present study, the use of Glass Fiber Reinforced Plastic (GFRP) plate/angle sections is explored to strengthen existing bolted connections in TL/communication towers. Experimental investigation conducted at component level on strengthening of existing two types of single cover steel butt joint, one made of steel plate and another joint made of steel angle sections respectively. First series of experiment conducted on strengthening the connection using GFRP plate/cleat angle sections. The second series of strengthening experiment is conducted using steel plate/angle sections to replace GFRP sections. The load sharing behaviour of strengthened GFRP and steel section is compared and suitable recommendations are given.

  5. Experimental Investigation on Strengthening of Bolted Connections in Transmission/Communication Towers

    Science.gov (United States)

    Balagopal, R.; Prasad Rao, N.; Rokade, R. P.; Umesha, P. K.

    2018-06-01

    Due to increase in demand for power supply and increase in bandwidth for communication industry, the existing transmission line (TL) and communication towers needs to be strengthened. The strengthening of existing tower is economical rather than installation of new towers due to constraints in acquisition of land. The size of conductors have to be increased or additional number of antenna needs to be installed in existing TL/communication tower respectively. The compression and tension capacity of members in the existing towers have to be increased to sustain the additional loads due to wind and self-weight of these components. The tension capacity enhancement of existing angle sections in live line condition without power shut-down is a challenging task. In the present study, the use of Glass Fiber Reinforced Plastic (GFRP) plate/angle sections is explored to strengthen existing bolted connections in TL/communication towers. Experimental investigation conducted at component level on strengthening of existing two types of single cover steel butt joint, one made of steel plate and another joint made of steel angle sections respectively. First series of experiment conducted on strengthening the connection using GFRP plate/cleat angle sections. The second series of strengthening experiment is conducted using steel plate/angle sections to replace GFRP sections. The load sharing behaviour of strengthened GFRP and steel section is compared and suitable recommendations are given.

  6. Optimum Design and Operation of an HVAC Cooling Tower for Energy and Water Conservation

    Directory of Open Access Journals (Sweden)

    Clemente García Cutillas

    2017-03-01

    Full Text Available The energy consumption increase in the last few years has contributed to developing energy efficiency policies in many countries, the main goal of which is decreasing CO 2 emissions. One of the reasons for this increment has been caused by the use of air conditioning systems due to new comfort standards. In that regard, cooling towers and evaporative condensers are presented as efficient devices that operate with low-level water temperature. Moreover, the energy consumption and the cost of the equipment are lower than other systems like air condensers at the same operation conditions. This work models an air conditioning system in TRNSYS software, the main elements if which are a cooling tower, a water-water chiller and a reference building. The cooling tower model is validated using experimental data in a pilot plant. The main objective is to implement an optimizing control strategy in order to reduce both energy and water consumption. Furthermore a comparison between three typical methods of capacity control is carried out. Additionally, different cooling tower configurations are assessed, involving six drift eliminators and two water distribution systems. Results show the influence of optimizing the control strategy and cooling tower configuration, with a maximum energy savings of 10.8% per story and a reduction of 4.8% in water consumption.

  7. Experimental investigation of the performance characteristics of a counterflow wet cooling tower

    International Nuclear Information System (INIS)

    Lemouari, M.; Boumaza, M.

    2010-01-01

    An experimental investigation of the performance characteristics of a counter flow wet cooling tower represented by the heat rejected by the tower and its thermal effectiveness is presented in this paper. The tower is filled with a 'VGA.' (Vertical Grid Apparatus) type packing which is 0.42 m high and contains four (04) galvanized sheets having a zigzag form, between which are disposed three (03) metallic vertical grids in parallel with a cross-sectional test area of 0.15 m - 0.148 m. The investigation is concerned mainly on the effect of the air, water flow rates and the inlet water temperatures on the thermal effectiveness of the cooling tower as well as the heat rejected by this tower from water to be cooled to the air stream discharged into the atmosphere. The two operating regimes which were observed during the air/water contact inside the tower, a Pellicular Regime (PR) and a Bubble and Dispersion Regime (BDR) appear to be important, as The BDR regime enables to cool larger amount of water flow rates, while the Pellicular regime results with higher thermal effectiveness. (authors)

  8. Design change of tower cooling water system for proton accelerator research center

    International Nuclear Information System (INIS)

    Jeon, G. P.; Kim, J. Y.; Song, I. T.; Min, Y. S.; Mun, K. J.; Cho, J. S.; Nam, J. M.; Park, S. S.; Han, Y. G.

    2012-01-01

    The Tower Cooling Water System (TC) is designed to reject the heat load generated by operating the accelerators and the utility facilities through the component cooling water (CCW) heat exchangers. The circulating water discharged from the circulating water pumps passes through the CCW heat exchangers, the Chiller condenser and the air compressor, and the heated circulating water is return to the cooling tower for the heat removal. In this study, The design of Tower Cooling Water System is changed as follows : At First, The quantity of cells is changed into six in order to operate the cooling tower accurately correspond with condition of each equipment of head loads. The fans of cooling tower are controlled by the signal of TEW installed in the latter parts of it. The type of circulation water pump is modified to centrifugal pump and debris filter system is deleted

  9. Data from an instrumented navigational light tower off the Savanah River estuary

    International Nuclear Information System (INIS)

    Hayes, D.W.; Dicks, A.S.; Blanton, J.O.

    1978-01-01

    An oceanographic and meteorological instrumentation system operating on the Savannah Navigational Light Tower is providing synoptic information on ocean temperatures, currents, tides, and meteorological conditions. The Savannah Navigational Light Tower, an unmanned U.S. Coast Guard tower, is located about nine miles off Savannah Beach, Georgia, in about 16 m of water. The tower is currently instrumented to measure and record water temperatures from six depths, water velocities at two depts, tides, air temperature, barometric pressure, and wind speed and velocity at two heights. The outputs are currently being recorded every 10 minutes. These data aid in the interpretation of the processes governing pollutant transport in the Savannah River marine region and support other DOE funded programs in the southeastern United States. This past year, computer programs were written and are being tested for processing the raw data from the tower and for performing correlative analysis of the data

  10. Design change of tower cooling water system for proton accelerator research center

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, G. P.; Kim, J. Y.; Song, I. T.; Min, Y. S.; Mun, K. J.; Cho, J. S.; Nam, J. M.; Park, S. S.; Han, Y. G. [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    The Tower Cooling Water System (TC) is designed to reject the heat load generated by operating the accelerators and the utility facilities through the component cooling water (CCW) heat exchangers. The circulating water discharged from the circulating water pumps passes through the CCW heat exchangers, the Chiller condenser and the air compressor, and the heated circulating water is return to the cooling tower for the heat removal. In this study, The design of Tower Cooling Water System is changed as follows : At First, The quantity of cells is changed into six in order to operate the cooling tower accurately correspond with condition of each equipment of head loads. The fans of cooling tower are controlled by the signal of TEW installed in the latter parts of it. The type of circulation water pump is modified to centrifugal pump and debris filter system is deleted.

  11. Active tower damping and pitch balancing – design, simulation and field test

    International Nuclear Information System (INIS)

    Duckwitz, Daniel; Shan, Martin

    2014-01-01

    The tower is one of the major components in wind turbines with a contribution to the cost of energy of 8 to 12% [1]. In this overview the load situation of the tower will be described in terms of sources of loads, load components and fatigue contribution. Then two load reduction control schemes are described along with simulation and field test results. Pitch Balancing is described as a method to reduce aerodynamic asymmetry and the resulting fatigue loads. Active Tower Damping is reducing the tower oscillations by applying appropiate pitch angle changes. A field test was conducted on an Areva M5000 wind turbine

  12. Wind-induced response of CN-Tower: comparison of model and full scale

    International Nuclear Information System (INIS)

    Monbaliu, J.; Ruigrok, C.; Isyumov, N.

    1985-01-01

    The approximately 555-m high CN Communications Tower in Toronto has now been operational for nearly a decade. The action of wind on this tower was extensively tested at the Boundary Layer Wind Tunnel Laboratory during the design of the tower. This study provided information on the overall wind loads and responses of the structure, the action of wind on various components, and its effects on the tower performance including transmission quality. A program of monitoring and recording the wind induced response and various meteorological data was started in 1977. This paper presents some results of that program and makes comparisons with wind tunnel model data. (author)

  13. Perhitungan Kebutuhan Cooling Tower Pada Rancang Bangun Untai Uji Sistem Kendali Reaktor Riset

    OpenAIRE

    Awwaluddin, Muhammad; Santosa, Puji; Suwardiyono, Suwardiyono

    2012-01-01

    CALCULATION OF THE NEED FOR COOLING TOWER ON DESIGN OF STRAND TEST RESEARCH REACTOR CONTROL SYSTEM. Cooling tower on the strand test engineering research reactor control system functioning as a heat transfer medium from the heat exchanger to air. To get the transfer of heat or cooling is maximal then the determination of cooling tower needs to be precise. Cooling tower is expected to accept and release heat at 1.191 kw from the heat exchanger. To support these needs will require the calculati...

  14. MODELLING AND ANALYSIS OF TOWER INTERVENTION EQUIPMENT OF OIL & GAS WELLS

    Directory of Open Access Journals (Sweden)

    César A. Chagoyén-Méndez

    2015-04-01

    Full Text Available In this paper, the modeling and analysis of one tower Workover Rig belonging to a maintenance facility for oil and gas wells is presented. When performing the maintenance of this tower, it is detected that one of the elements of the structure has some deformation. It was decided not to put it into operation and submit it to research. The modeling of invariants as well as ways of modeling soil structure interaction is discussed. It was necessary to determine the material properties with the performing of test of some samples taken on two components of the tower. The structural behavior of the tower to operating loads are then studied, proving that the effect of the deformed element in the structure is not significant for the stresses to which are subject.

  15. Solar Power Tower Design Basis Document, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    ZAVOICO,ALEXIS B.

    2001-07-01

    This report contains the design basis for a generic molten-salt solar power tower. A solar power tower uses a field of tracking mirrors (heliostats) that redirect sunlight on to a centrally located receiver mounted on top a tower, which absorbs the concentrated sunlight. Molten nitrate salt, pumped from a tank at ground level, absorbs the sunlight, heating it up to 565 C. The heated salt flows back to ground level into another tank where it is stored, then pumped through a steam generator to produce steam and make electricity. This report establishes a set of criteria upon which the next generation of solar power towers will be designed. The report contains detailed criteria for each of the major systems: Collector System, Receiver System, Thermal Storage System, Steam Generator System, Master Control System, and Electric Heat Tracing System. The Electric Power Generation System and Balance of Plant discussions are limited to interface requirements. This design basis builds on the extensive experience gained from the Solar Two project and includes potential design innovations that will improve reliability and lower technical risk. This design basis document is a living document and contains several areas that require trade-studies and design analysis to fully complete the design basis. Project- and site-specific conditions and requirements will also resolve open To Be Determined issues.

  16. Validation of Simplified Load Equations Through Loads Measurement and Modeling of a Small Horizontal-Axis Wind Turbine Tower

    Energy Technology Data Exchange (ETDEWEB)

    Dana, Scott [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Van Dam, Jeroen J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Damiani, Rick R [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-04-24

    As part of an ongoing effort to improve the modeling and prediction of small wind turbine dynamics, the National Renewable Energy Laboratory (NREL) tested a small horizontal-axis wind turbine in the field at the National Wind Technology Center. The test turbine was a 2.1-kW downwind machine mounted on an 18-m multi-section fiberglass composite tower. The tower was instrumented and monitored for approximately 6 months. The collected data were analyzed to assess the turbine and tower loads and further validate the simplified loads equations from the International Electrotechnical Commission (IEC) 61400-2 design standards. Field-measured loads were also compared to the output of an aeroelastic model of the turbine. In particular, we compared fatigue loads as measured in the field, predicted by the aeroelastic model, and calculated using the simplified design equations. Ultimate loads at the tower base were assessed using both the simplified design equations and the aeroelastic model output. The simplified design equations in IEC 61400-2 do not accurately model fatigue loads and a discussion about the simplified design equations is discussed.

  17. Improved reliability of wind turbine towers with active tuned mass dampers (ATMDs)

    Science.gov (United States)

    Fitzgerald, Breiffni; Sarkar, Saptarshi; Staino, Andrea

    2018-04-01

    Modern multi-megawatt wind turbines are composed of slender, flexible, and lightly damped blades and towers. These components exhibit high susceptibility to wind-induced vibrations. As the size, flexibility and cost of the towers have increased in recent years, the need to protect these structures against damage induced by turbulent aerodynamic loading has become apparent. This paper combines structural dynamic models and probabilistic assessment tools to demonstrate improvements in structural reliability when modern wind turbine towers are equipped with active tuned mass dampers (ATMDs). This study proposes a multi-modal wind turbine model for wind turbine control design and analysis. This study incorporates an ATMD into the tower of this model. The model is subjected to stochastically generated wind loads of varying speeds to develop wind-induced probabilistic demand models for towers of modern multi-megawatt wind turbines under structural uncertainty. Numerical simulations have been carried out to ascertain the effectiveness of the active control system to improve the structural performance of the wind turbine and its reliability. The study constructs fragility curves, which illustrate reductions in the vulnerability of towers to wind loading owing to the inclusion of the damper. Results show that the active controller is successful in increasing the reliability of the tower responses. According to the analysis carried out in this paper, a strong reduction of the probability of exceeding a given displacement at the rated wind speed has been observed.

  18. Integration of Small Solar tower Systems into Distributed Power Islands

    Energy Technology Data Exchange (ETDEWEB)

    Romero, M.; Marcos, M. J.; Tellez, F. M.; Blanco, M.; Fernandez, V.; Baonza, F.; Berger, S. [Ciemat, Madrid (Spain)

    2000-07-01

    One of the short-term priorities for renewable energies in Europe is their integration for local power supply into communities and energy islands (blocks of buildings, new neighborhoods in residential areas, shopping centers, hospitals, recreational areas, eco-paks, small rural areas or isolated ones such as islands or mountain communities). Following this strategy, the integration of small tower fields into so-called MIUS (Modular Integrated Utility Systems) is proposed. This application strongly influences field concepts leadings to modular multi-tower systems able to more closely track demand, meet reliability requirements with fewer megawatts of installed power and spread construction costs over time after output has begum. In addition, integration into single-cycle high-efficiency gas turbines plus waste-heat applications clearly increments the solar share. The chief questions are whether solar towers can be redesigned for such distributed markets and the keys to their feasibility. This paper includes the design and performance analysis of a 1.36-MW plant and integration in the MIUS system, as well as the expected cost of electricity and a sensitivity analysis of the small tower plant's performance with design parameters like heliostat configuration and tower height. A practical application is analyzed for a shopping center with 85% power demand during day-time by using a hybrid solar tower and a gas turbine producing electricity and waste heat for hot water and heating and cooling of spaces. The operation mode proposed is covering night demand with power from the grid and solar-gas power island mode during 14 hours daytime with a maximum power production of 1.36 MW. (Author) 26 refs.

  19. Integration of Small Solar Tower Systems Into Distributed Power Islands

    International Nuclear Information System (INIS)

    Romero, M.; Marcos, M. J.; Tellez, F. M.; Blanco, M.; Fernandez, V.; Baonza, F.; Berger, S.

    1999-01-01

    One of the short-term priorities for renewable energies in Europe is their integration for local power supply into communities and energy islands (blocks of buildings, new neighborhoods in residential areas, shopping centers, hospitals, recreational areas, eco-parks, small rural areas or isolated ones such as islands or mountain communities). Following this strategy, the integration of small tower fields into so-called MIUS (Modular Integrated Utility Systems) is proposed. This application strongly influences field concepts leading to modular multi-tower systems able to more closely track demand, meet reliability requirements with fewer megawatts of installed power and spread construction costs over time after output has begun. In addition, integration into single-cycle high-efficiency gas turbines plus waste-heat applications clearly increments the solar share. The chief questions are whether solar towers can be redesigned for such distributed markets and the keys to their feasibility. This paper includes the design and performance analysis of a 1.36-MW plant and integration in the MIUS system, as well as the expected cost of electricity and a sensitivity analysis of the small tower plant's performance with design parameters like heliostats configuration and tower height. A practical application is analyzed for a shopping center with 85% power demand during day-time by using a hybrid solar tower and a gas turbine producing electricity and waste heat for hot water and heating and cooling of spaces. The operation mode proposed is covering night demand with power from the grid and solar-gas power island mode during 14 hours daytime with a maximum power production of 1.36 MW. (Author) 26 refs

  20. Analysis of the evaporative towers cooling system of a coal-fired power plant

    Directory of Open Access Journals (Sweden)

    Laković Mirjana S.

    2012-01-01

    Full Text Available The paper presents a theoretical analysis of the cooling system of a 110 MW coal-fired power plant located in central Serbia, where eight evaporative towers cool down the plant. An updated research on the evaporative tower cooling system has been carried out to show the theoretical analysis of the tower heat and mass balance, taking into account the sensible and latent heat exchanged during the processes which occur inside these towers. Power plants which are using wet cooling towers for cooling condenser cooling water have higher design temperature of cooling water, thus the designed condensing pressure is higher compared to plants with a once-through cooling system. Daily and seasonal changes further deteriorate energy efficiency of these plants, so it can be concluded that these plants have up to 5% less efficiency compared to systems with once-through cooling. The whole analysis permitted to evaluate the optimal conditions, as far as the operation of the towers is concerned, and to suggest an improvement of the plant. Since plant energy efficiency improvement has become a quite common issue today, the evaluation of the cooling system operation was conducted under the hypothesis of an increase in the plant overall energy efficiency due to low cost improvement in cooling tower system.

  1. Theoretical and experimental study of a cross-flow induced-draft cooling tower

    Directory of Open Access Journals (Sweden)

    Abo Elazm Mahmoud Mohamed

    2009-01-01

    Full Text Available The main objective of this study is to find a proper solution for the cross-flow water cooling tower problem, also to find an empirical correlation's controlling heat and mass transfer coefficients as functions of inlet parameters to the tower. This is achieved by constructing an experimental rig and a computer program. The computer simulation solves the problem numerically. The apparatus used in this study comprises a cross-flow cooling tower. From the results obtained, the 'characteristic curve' of cross-flow cooling towers was constructed. This curve is very helpful for designers in order to find the actual value of the number of transfer units, if the values of inlet water temperature or inlet air wet bulb temperature are changed. Also an empirical correlation was conducted to obtain the required number of transfer units of the tower in hot water operation. Another correlation was found to obtain the effectiveness in the wet bulb operation.

  2. Captain Nemo/Lt-General Pitt Rivers and Cleopatra’s Needle — A Story of Flagships

    Directory of Open Access Journals (Sweden)

    Christopher Evans

    2005-11-01

    Full Text Available Recently re-reading Verne’s 20,000 Leagues Beneath the Sea for our children I was struck by the marked similarities between the novel’s elusive protagonist, Captain Nemo, and the renowned later 19th century British archaeologist, Lt.-General Pitt Rivers. Could they have been the same person? How could something so seemingly blatant have gone unnoticed? These questions are, of course, only raised in a spirit of academic tongue-in-check. Yet, in an ethos of ‘learning through amusement’ (itself directly relevant to the themes of this study, exploring the parallels between these two ‘heroic’ individuals provides insights into the nature of 19th century science, Victorian edification and disciplinary institutionalisation (e.g. Levine 1986. This eclectic contribution will, moreover, be introduced with the third component of its headline title – Cleopatra’s Needle – as this provides an appropriately quasinautical parable on the project of 19th century archaeology and the problem of ‘deep time’ (Murray 1993.

  3. New student-designed research and demonstration drop tower

    Science.gov (United States)

    Bell, Donald; Weislogel, Mark

    A new drop tower has been designed and constructed at Portland State University. The ap-proach incorporates innovative features to increase throughput and microgravity quality in a highly public facility. Push button operation with full wireless CCTV coverage and passive magnetic deceleration provides quiet, safe operation from a single control station with low re-cycle time. A two-stage coaxial release mechanism decouples the payload from the drag shield to minimize disturbances to the experiment during release. This is especially important for fluids experiments that are highly sensitive to initial conditions. Performance of the new tower is presented including release, free fall, and deceleration accelerometer data. The two second tower is used for research and educational outreach. The research efforts focus on capillary flows and phenomena relevant to spacecraft fluid systems. The outreach efforts utilize partnerships with local primary, secondary and post-secondary institutions to promote the fields of science, technology, engineering and mathematics.

  4. Fatigue Reliability Analysis of a Mono-Tower Platform

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Sørensen, John Dalsgaard; Brincker, Rune

    1991-01-01

    In this paper, a fatigue reliability analysis of a Mono-tower platform is presented. The failure mode, fatigue failure in the butt welds, is investigated with two different models. The one with the fatigue strength expressed through SN relations, the other with the fatigue strength expressed thro...... of the natural period, damping ratio, current, stress spectrum and parameters describing the fatigue strength. Further, soil damping is shown to be significant for the Mono-tower.......In this paper, a fatigue reliability analysis of a Mono-tower platform is presented. The failure mode, fatigue failure in the butt welds, is investigated with two different models. The one with the fatigue strength expressed through SN relations, the other with the fatigue strength expressed...... through linear-elastic fracture mechanics (LEFM). In determining the cumulative fatigue damage, Palmgren-Miner's rule is applied. Element reliability, as well as systems reliability, is estimated using first-order reliability methods (FORM). The sensitivity of the systems reliability to various parameters...

  5. Optimum Tower Crane Selection and Supporting Design Management

    Directory of Open Access Journals (Sweden)

    Hyo Won Sohn

    2014-08-01

    Full Text Available To optimize tower crane selection and supporting design, lifting requirements (as well as stability should be examined, followed by a review of economic feasibility. However, construction engineers establish plans based on data provided by equipment suppliers since there are no tools with which to thoroughly examine a support design's suitability for various crane types, and such plans lack the necessary supporting data. In such cases it is impossible to optimize a tower crane selection to satisfy lifting requirements in terms of cost, and to perform lateral support and foundation design. Thus, this study is intended to develop an optimum tower crane selection and supporting design management method based on stability. All cases that are capable of generating an optimization of approximately 3,000 ˜ 15,000 times are calculated to identify the candidate cranes with minimized cost, which are examined. The optimization method developed in the study is expected to support engineers in determining the optimum lifting equipment management.

  6. LOOP CALCULUS AND BELIEF PROPAGATION FOR Q-ARY ALPHABET: LOOP TOWER

    Energy Technology Data Exchange (ETDEWEB)

    CHERTKOV, MICHAEL [Los Alamos National Laboratory; CHERNYAK, VLADIMIR [Los Alamos National Laboratory

    2007-01-10

    Loop calculus introduced in [1], [2] constitutes a new theoretical tool that explicitly expresses symbol Maximum-A-Posteriori (MAP) solution of a general statistical inference problem via a solution of the Belief Propagation (BP) equations. This finding brought a new significance to the BP concept, which in the past was thought of as just a loop-free approximation. In this paper they continue a discussion of the Loop Calculus, partitioning the results into three Sections. In Section 1 they introduce a new formulation of the Loop Calculus in terms of a set of transformations (gauges) that keeping the partition function of the problem invariant. The full expression contains two terms referred to as the 'ground state' and 'excited states' contributions. The BP equations are interpreted as a special (BP) gauge fixing condition that emerges as a special orthogonality constraint between the ground state and excited states, which also selects loop contributions as the only surviving ones among the excited states. In Section 2 they demonstrate how the invariant interpretation of the Loop Calculus, introduced in Section 1, allows a natural extension to the case of a general q-ary alphabet, this is achieved via a loop tower sequential construction. The ground level in the tower is exactly equivalent to assigning one color (out of q available) to the 'ground state' and considering all 'excited' states colored in the remaining (q-1) colors, according to the loop calculus rule. Sequentially, the second level in the tower corresponds to selecting a loop from the previous step, colored in (q-1) colors, and repeating the same ground vs excited states splitting procedure into one and (q-2) colors respectively. The construction proceeds till the full (q-1)-levels deep loop tower (and the corresponding contributions to the partition function) are established. In Section 3 they discuss an ultimate relation between the loop calculus and the Bethe

  7. Talking Towers, Making Withs.

    Science.gov (United States)

    Lemke, J. L.

    The notion of a linguistic "register" is useful in posing questions about how the ways language is used differ from one kind of human activity to another. This paper analyzes a videotaped segment of male grade 4/5 students (n=3) who are talking as they work to build a tower from plastic drinking straws and pins. Discussion of the…

  8. Coastal Land Air Sea Interaction: "the" beach towers

    Science.gov (United States)

    MacMahan, J. H.; Koscinski, J. S.; Ortiz-Suslow, D. G.; Haus, B. K.; Thornton, E. B.

    2016-12-01

    As part of the Coastal Land Air Sea Interaction (CLASI) experiment, an alongshore array of 6-m high towers instrumented with ultrasonic 3D anemometers and temperature-relative humidity sensors were deployed at five sandy beaches near the high-tide line in Monterey Bay, CA, in May-June 2016. A cross-shore array of towers was also deployed from within the active surfzone to the toe of the dune at one beach. In addition, waves and ocean temperature were obtained along the 10m isobath for each beach. The dissipative surfzone was O(80m) wide. The wave energy varies among the beaches owing to sheltering and refraction by the Monterey Canyon and headlands. The tides are semi-diurnal mixed, meso-tidal with a maximum tidal range of 2m. This results in a variable beach width from the tower to the tidal line. Footprint analysis for estimating the source region for the turbulent momentum fluxes, suggests that the observations represent three scenarios described as primarily ocean, mixed beach and ocean, and primarily beach. The direct-estimate of the atmospheric stability by the sonic anemometer suggest that all of the beaches are mostly unstable except for a few occurrences in the evening during low wind conditions. The onshore neutral drag coefficient (Cd) estimated at 10m heights is 3-5 times larger than open ocean estimates. Minimal variability was found in Cd based on the footprint analysis. Beach-specific spatial variability in Cd was found related to atmospheric stability and wave energy.

  9. Calibration and field testing of cavity ring-down laser spectrometers measuring CH4, CO2, and δ13CH4 deployed on towers in the Marcellus Shale region

    Directory of Open Access Journals (Sweden)

    N. L. Miles

    2018-03-01

    Full Text Available Four in situ cavity ring-down spectrometers (G2132-i, Picarro, Inc. measuring methane dry mole fraction (CH4, carbon dioxide dry mole fraction (CO2, and the isotopic ratio of methane (δ13CH4 were deployed at four towers in the Marcellus Shale natural gas extraction region of Pennsylvania. In this paper, we describe laboratory and field calibration of the analyzers for tower-based applications and characterize their performance in the field for the period January–December 2016. Prior to deployment, each analyzer was tested using bottles with various isotopic ratios, from biogenic to thermogenic source values, which were diluted to varying degrees in zero air, and an initial calibration was performed. Furthermore, at each tower location, three field tanks were employed, from ambient to high mole fractions, with various isotopic ratios. Two of these tanks were used to adjust the calibration of the analyzers on a daily basis. We also corrected for the cross-interference from ethane on the isotopic ratio of methane. Using an independent field tank for evaluation, the standard deviation of 4 h means of the isotopic ratio of methane difference from the known value was found to be 0.26 ‰ δ13CH4. Following improvements in the field tank testing scheme, the standard deviation of 4 h means was 0.11 ‰, well within the target compatibility of 0.2 ‰. Round-robin style testing using tanks with near-ambient isotopic ratios indicated mean errors of −0.14 to 0.03 ‰ for each of the analyzers. Flask to in situ comparisons showed mean differences over the year of 0.02 and 0.08 ‰, for the east and south towers, respectively. Regional sources in this region were difficult to differentiate from strong perturbations in the background. During the afternoon hours, the median differences of the isotopic ratio measured at three of the towers, compared to the background tower, were &minus0.15 to 0.12 ‰ with standard deviations of the 10

  10. Calibration and field testing of cavity ring-down laser spectrometers measuring CH4, CO2, and δ13CH4 deployed on towers in the Marcellus Shale region

    Science.gov (United States)

    Miles, Natasha L.; Martins, Douglas K.; Richardson, Scott J.; Rella, Christopher W.; Arata, Caleb; Lauvaux, Thomas; Davis, Kenneth J.; Barkley, Zachary R.; McKain, Kathryn; Sweeney, Colm

    2018-03-01

    Four in situ cavity ring-down spectrometers (G2132-i, Picarro, Inc.) measuring methane dry mole fraction (CH4), carbon dioxide dry mole fraction (CO2), and the isotopic ratio of methane (δ13CH4) were deployed at four towers in the Marcellus Shale natural gas extraction region of Pennsylvania. In this paper, we describe laboratory and field calibration of the analyzers for tower-based applications and characterize their performance in the field for the period January-December 2016. Prior to deployment, each analyzer was tested using bottles with various isotopic ratios, from biogenic to thermogenic source values, which were diluted to varying degrees in zero air, and an initial calibration was performed. Furthermore, at each tower location, three field tanks were employed, from ambient to high mole fractions, with various isotopic ratios. Two of these tanks were used to adjust the calibration of the analyzers on a daily basis. We also corrected for the cross-interference from ethane on the isotopic ratio of methane. Using an independent field tank for evaluation, the standard deviation of 4 h means of the isotopic ratio of methane difference from the known value was found to be 0.26 ‰ δ13CH4. Following improvements in the field tank testing scheme, the standard deviation of 4 h means was 0.11 ‰, well within the target compatibility of 0.2 ‰. Round-robin style testing using tanks with near-ambient isotopic ratios indicated mean errors of -0.14 to 0.03 ‰ for each of the analyzers. Flask to in situ comparisons showed mean differences over the year of 0.02 and 0.08 ‰, for the east and south towers, respectively. Regional sources in this region were difficult to differentiate from strong perturbations in the background. During the afternoon hours, the median differences of the isotopic ratio measured at three of the towers, compared to the background tower, were &minus0.15 to 0.12 ‰ with standard deviations of the 10 min isotopic ratio differences of 0.8

  11. Humidification tower for humid air gas turbine cycles: Experimental analysis

    International Nuclear Information System (INIS)

    Traverso, A.

    2010-01-01

    In the HAT (humid air turbine) cycle, the humidification of compressed air can be provided by a pressurised saturator (i.e. humidification tower or saturation tower), this solution being known to offer several attractive features. This work is focused on an experimental study of a pressurised humidification tower, with structured packing. After a description of the test rig employed to carry out the measuring campaign, the results relating to the thermodynamic process are presented and discussed. The experimental campaign was carried out over 162 working points, covering a relatively wide range of possible operating conditions. It is shown that the saturator behaviour, in terms of air outlet humidity and temperature, is primarily driven by, in decreasing order of relevance, the inlet water temperature, the inlet water over inlet dry air mass flow ratio and the inlet air temperature. The exit relative humidity is consistently over 100%, which may be explained partially by measurement accuracy and droplet entrainment, and partially by the non-ideal behaviour of air-steam mixtures close to saturation. Experimental results have been successfully correlated using a set of new non-dimensional groups: such a correlation is able to capture the air outlet temperature with a standard deviation σ = 2.8 K.

  12. How tall can gelatin towers be? An introduction to elasticity and buckling

    Science.gov (United States)

    Taberlet, Nicolas; Ferrand, Jérémy; Camus, Élise; Lachaud, Léa; Plihon, Nicolas

    2017-12-01

    The stability of elastic towers is studied through simple hands-on experiments. Using gelatin-based stackable bricks, one can investigate the maximum height a simple structure can reach before collapsing. We show through experiments and by using the classical linear elastic theory that the main limitation to the height of such towers is the buckling of the elastic structures under their own weight. Moreover, the design and architecture of the towers can be optimized to greatly improve their resistance to self-buckling. To this aim, the maximum height of hollow and tapered towers is investigated. The experimental and theoretical developments presented in this paper can help students grasp the fundamental concepts in elasticity and mechanical stability.

  13. Induced flocculation of Pachysolen tannophilus using the tower fermentor

    Energy Technology Data Exchange (ETDEWEB)

    Deverell, K.F.; Clark, T.A.

    1985-12-01

    This article reports the induction of flocculation with Pachysolen tannophilus by the use of controlled aeration in a tower fermentor. The observed environmental and physiological conditions for flocculent growth are described. Although most studies with P. tannophilus have used oxylose as substrate, a synthetic glucose medium was chosen for this study as the faster growth rate of the organism on glucose was considered to favor more rapid selection of a flocculent strain. Due to flocculation, the concentration of yeast cells retained in the tower was up to 16 times greater than in the overflow. Ethanol yields approaching theoretical were achieved at low specific oxygen uptake rates, conditions which also favored maximum flocculation. Future work will involve continuous tower fermentation of sugar mixtures representative of the composition of wood hydrolysates.

  14. Cooling Tower Overhaul of Secondary Cooling System in HANARO

    Energy Technology Data Exchange (ETDEWEB)

    Park, Young Chul; Lee, Young Sub; Jung, Hoan Sung; Lim, In Chul [KAERI, Daejeon (Korea, Republic of)

    2007-07-01

    HANARO, an open-tank-in-pool type research reactor of 30 MWth power in Korea, has been operating normally since its initial criticality in February, 1995. For the last about ten years, A cooling tower of a secondary cooling system has been operated normally in HANARO. Last year, the cooling tower has been overhauled for preservative maintenance including fills, eliminators, wood support, water distribution system, motors, driving shafts, gear reducers, basements, blades and etc. This paper describes the results of the overhaul. As results, it is confirmed that the cooling tower maintains a good operability through a filed test. And a cooling capability will be tested when a wet bulb temperature is maintained about 28 .deg. C in summer and the reactor is operated with the full power.

  15. Measurements on cooling tower plumes. Pt. 3

    International Nuclear Information System (INIS)

    Fortak, H.

    1975-11-01

    In this paper an extended field experiment is described in which cooling tower plumes were investigated by means of three-dimensional in situ measurements. The goal of this program was to obtain input data for numerical models of cooling tower plumes. Data for testing or developing assumptions for sub-grid parametrizations were of special interest. Utilizing modern systems for high-resolution aerology and small aircraft, four measuring campaigns were conducted: two campaigns (1974) at the cooling towers of the RWE power station at Neurath and also two (1975) at the single cooling tower of the RWE power station at Meppen. Because of the broad spectrum of weather situations, it can be assumed that the results are representative with regard to the interrelationship between the structure of cooling tower plumes and the large-scale meteorological situation. A large number of flights with a powered glider ASK 16 (more than 100 flight hours) crossing the plumes on orthogonal tracks was performed. All flights showed that the plume could be identified up to large downwind distances by discontinuous jumps of temperature and vapour pressure. Therefore a definite geometry of the plume could always be defined. In all cross sections a vertical circulation could be observed. At the plumes boundaries, which could be defined by the mentioned jumps of temperature and vapour pressure, a maximum of downward vertical motion was observed in most cases. Entrainment along the boundary of a cross section seems to be very small, except at the lower part of the plume. There, the mass entrainment is maximum and is responsible for plume rise as well as for enlargement of the cross section. The visible part of the plume (cloud) was only a small fraction of the whole plume. The discontinuities of temperature and vapour pressure show that the plume fills the space below the visible plume down to the ground. However, all effects decrease rapidly towards the ground. It turned out that high

  16. Design and Manufacturing of Composite Tower Structure for Wind Turbine Equipment

    Science.gov (United States)

    Park, Hyunbum

    2018-02-01

    This study proposes the composite tower design process for large wind turbine equipment. In this work, structural design of tower and analysis using finite element method was performed. After structural design, prototype blade manufacturing and test was performed. The used material is a glass fiber and epoxy resin composite. And also, sand was used in the middle part. The optimized structural design and analysis was performed. The parameter for optimized structural design is weight reduction and safety of structure. Finally, structure of tower will be confirmed by structural test.

  17. Wind Shear Characteristics at Central Plains Tall Towers (presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, M.; Elliott, D.

    2006-06-05

    The objectives of this report are: (1) Analyze wind shear characteristics at tall tower sites for diverse areas in the central plains (Texas to North Dakota)--Turbines hub heights are now 70-100 m above ground and Wind measurements at 70-100+ m have been rare. (2) Present conclusions about wind shear characteristics for prime wind energy development regions.

  18. Wind towers architecture, climate and sustainability

    CERN Document Server

    Bahadori, Mehdi N; Sayigh, Ali

    2014-01-01

    This book offers a holistic treatment of wind towers, from their underlying scientific principles to design and operation. Includes suggestions for optimization based on the authors' own research findings from recent analytical studies.

  19. Two upward lightning at the Eagle Nest tower

    OpenAIRE

    Montañá Puig, Juan; Van der Velde, Oscar Arnoud; Romero Durán, David; March Nomen, Víctor; Solà de Las Fuentes, Gloria; Pineda Ruegg, Nicolau; Soula, Serge; Hermoso Alameda, Blas

    2012-01-01

    A new instrument composed by a high speed camera, two high energy detectors, a E-field antenna and a VHF antenna were installed at the Eagle Nest tower (northeast of Spain) during summer 2011. With this equipment several lightning flashes to the tower and its vicinity have been observed. This paper presents two examples: the first was an upward negative leader triggered by a close c1oud-to-ground flash and the second was an upward negative flash not associated with previous lightning activity...

  20. Legionnaires' Disease Outbreak at a Long-Term Care Facility Caused by a Cooling Tower Using an Automated Disinfection System--Ohio, 2013.

    Science.gov (United States)

    Quinn, Celia; Demirjian, Alicia; Watkins, Louise Francois; Tomczyk, Sara; Lucas, Claressa; Brown, Ellen; Kozak-Muiznieks, Natalia; Benitez, Alvaro; Garrison, Laurel E; Kunz, Jasen; Brewer, Scott; Eitniear, Samantha; DiOrio, Mary

    2015-12-01

    On July 9, 2013, an outbreak of Legionnaires' disease (LD) was identified at Long-Term Care Facility A in central Ohio. This article describes the investigation of the outbreak and identification of the outbreak source, a cooling tower using an automated biocide delivery system. In total, 39 outbreak LD cases were identified; among these, six patients died. Water samples from a cooling tower were positive for Legionella pneumophila serogroup 1, reactive to monoclonal antibody 2, with matching sequence type to a patient isolate. An electronic control system turned off cooling tower pumps during low-demand periods, preventing delivery of disinfectant by a timed-release system, and leading to amplification of Legionella in the cooling tower. Guidelines for tower maintenance should address optimal disinfection when using automated systems.

  1. Visibility analysis of fire lookout towers in the Boyabat State Forest Enterprise in Turkey.

    Science.gov (United States)

    Kucuk, Omer; Topaloglu, Ozer; Altunel, Arif Oguz; Cetin, Mehmet

    2017-07-01

    For a successful fire suppression, it is essential to detect and intervene forest fires as early as possible. Fire lookout towers are crucial assets in detecting forest fires, in addition to other technological advancements. In this study, we performed a visibility analysis on a network of fire lookout towers currently operating in a relatively fire-prone region in Turkey's Western Black Sea region. Some of these towers had not been functioning properly; it was proposed that these be taken out of the grid and replaced with new ones. The percentage of visible areas under the current network of fire lookout towers was 73%; it could rise to 81% with the addition of newly proposed towers. This study was the first research to conduct a visibility analysis of current and newly proposed fire lookout towers in the Western Black Sea region and focus on its forest fire problem.

  2. Comparative study on thermal performance of natural draft cooling towers with finned shells

    International Nuclear Information System (INIS)

    Goodarzi, Mohsen

    2016-01-01

    The cooling efficiency of natural draft cooling towers under crosswind condition should be improved. In the present research work three different externally finned shells were considered for a typical natural draft cooling tower to investigate the cooling improvement. They were numerically simulated under normal and crosswind conditions. Numerical results show that twisting four fin plates over the tower shell along the 45 peripheral angle, could improve the cooling efficiency up to 6.5 %. Because of the periodic shape of the fin plates, the cooling efficiency of the cooling tower with finned shell is less sensitive to the change of wind.

  3. Comparative study on thermal performance of natural draft cooling towers with finned shells

    Energy Technology Data Exchange (ETDEWEB)

    Goodarzi, Mohsen [Bu-Ali Sina Univ., Hamedan (Iran, Islamic Republic of). Dept. of Mechanical Engineering

    2016-10-15

    The cooling efficiency of natural draft cooling towers under crosswind condition should be improved. In the present research work three different externally finned shells were considered for a typical natural draft cooling tower to investigate the cooling improvement. They were numerically simulated under normal and crosswind conditions. Numerical results show that twisting four fin plates over the tower shell along the 45 peripheral angle, could improve the cooling efficiency up to 6.5 %. Because of the periodic shape of the fin plates, the cooling efficiency of the cooling tower with finned shell is less sensitive to the change of wind.

  4. Wind tunnel experiments on cooling tower plumes. Pt. 2

    International Nuclear Information System (INIS)

    Andreopoulos, J.

    1986-01-01

    The basic characteristics of plumes issuing into a boundary layer type of cross flow are reported. The flow can be considered as an interaction between two vorticity fields with different length scales and turbulence intensities. The large eddies of the oncoming boundary layer are responsible for the observed sudden changes in the plume direction. The type of structures emanating the tower depends on the instantaneous velocity ratio. Mean velocities and normal velocity gradients are smaller than in the case of uniform cross-flow (Andreopoulos, 1986) and therefore the measured turbulence intensities were lower too. The cross-stream turbulence brings high momentum fluid into the wake region and the velocity defect decays very rapidly. Dilution of the plumes takes place faster in the presence of external turbulence than in the case with uniform cross-flow. The spreading rate is increased dramatically by the external turbulence which causes different effects on the hydrodynamic and thermal fields. (orig.) [de

  5. Further investigation on the performance of a shower cooling tower

    International Nuclear Information System (INIS)

    Qi Xiaoni; Liu Zhenyan

    2008-01-01

    This study was prompted by the need to design towers for applications in which, due to salt deposition on the packing and subsequent blockage, the use of tower packing is not practical. In the previous model we presented [Qi Xiaoni, Liu Zhenyan, Li Dandan. Performance characteristics of a shower cooling tower. Energy Convers Manage 2007;48(1):193-203.], three critical assumptions were made to reduce the complexity and computational time, which can also reduce the models' accuracy. Accurate modelling of the operating process is a determining factor both for designing the shower cooling tower (SCT) and for optimising its operation. In this paper, we derive a new model without applying the three assumptions. According to the condition of the outlet air, the governing equations consider two cases, including the supersaturated and unsaturated states. This model is used to predict the performance of a full scale SCT located in China with different conditions for validation. The differences in the heat and mass transfer analyses of the two models are described at different atmospheric conditions

  6. 40 CFR 61.134 - Standard: Naphthalene processing, final coolers, and final-cooler cooling towers.

    Science.gov (United States)

    2010-07-01

    ... coolers, and final-cooler cooling towers. 61.134 Section 61.134 Protection of Environment ENVIRONMENTAL... Standard: Naphthalene processing, final coolers, and final-cooler cooling towers. (a) No (“zero”) emissions are allowed from naphthalene processing, final coolers and final-cooler cooling towers at coke by...

  7. Experimental investigation of the hydraulic characteristics of a counter flow wet cooling tower

    International Nuclear Information System (INIS)

    Lemouari, M.; Boumaza, M.; Kaabi, A.

    2011-01-01

    Thermal and nuclear electric power plants as well as several industrial processes invariably discharge considerable energy to their surrounding by heat transfer. Although water drawn from a nearby river or lake can be employed to carry away this energy, cooling towers offer an excellent alternative particularly in locations where sufficient cooling water cannot be easily obtained from natural sources or where concern for the environment imposes some limits on the temperature at which cooling water can be returned to the surrounding. This paper concerns an experimental investigation of the hydraulic characteristics of a counter flow wet cooling tower. The tower contains a 'VGA.' (Vertical Grid Apparatus) type packing which is 0.42 m high and consists of four (04) galvanised sheets having a zigzag form, between which are disposed three (03) metallic vertical grids in parallel with a cross sectional test area of 0.15 m x 0.148 m. The present investigation is focused mainly on the effect of the air and water flow rates on the hydraulic characteristics of the cooling tower, for different inlet water temperatures. The two hydrodynamic operating regimes which were observed during the air/water contact operation within the tower, namely the Pellicular Regime (PR) and the Bubble and Dispersion Regime (BDR) have enabled to distinguish two different states of pressure drop characteristics. The first regime is characterized by low pressure drop values, while in the second regime, the pressure drop values are relatively much higher than those observed in the first one. The dependence between the pressure drop characteristics and the combined heat and mass transport (air-water) through the packing inside the cooling tower is also highlighted. The obtained results indicate that this type of tower possesses relatively good hydraulic characteristics. This leads to the saving of energy. -- Highlights: → Cooling towers are widely used to reject waste heat from thermal and nuclear

  8. Design of cooling towers by the effectiveness-NTU method

    International Nuclear Information System (INIS)

    Jaber, H.; Webb, R.L.

    1989-01-01

    This paper develops the effectiveness-NTU, number of transfer units, design method for cooling towers. The definitions for effectiveness and NTU are totally consistent with the fundamental definitions used in heat exchanger design. Sample calculations are presented for counter and crossflow cooling towers. Using the proper definitions, a person competent in heat transfer design can easily use the same basic method to design a cooling tower of counter, cross, or parallel flow configuration. The problems associated with the curvature of the saturated air enthalpy line are also treated. A one-increment design ignores the effect of this curvature. Increased precision can be obtained by dividing the cooling range into two or more increments. The standard effectiveness-NYU method is then used for each of the increments. Calculations are presented to define the error associated with different numbers of increments. This defines the number of increments required to attain a desired degree of precision. The authors also summarize the LMED method introduced by Berman, and show that this is totally consistent with the effectiveness-NTU method. Hence, using proper and consistent terms, heat exchanger designers are shown how to use either the standard Log-Mean Enthalpy Method (LMED) or effectiveness-NTU design methods to design cooling towers

  9. Tokyo Tower and Tokyo Skytree: History and Symbolism in Contemporary Japan

    Directory of Open Access Journals (Sweden)

    Yunuen Ysela Mandujano-Salazar

    2016-12-01

    Full Text Available The Tokyo Tower and the Tokyo Skytree are the two most recognizable landmarks on the skyline of Japan’s capital. By means of a documental revision, a textual interpretative analysis of media contents, participant observation and unstructured interviews, the objective of this article is to identify the development of these towers as symbols of Tokyo and Japan. It is found that, with more than half a century of existence, the Tokyo Tower represents the successful post-war Japanese society, while in just five years the Tokyo Skytree has become a symbol of Japanese national spirit and resilience in an era of multiple crises. Both broadcasting towers are regularly portrayed in Japanese media linked to narratives of romance, dreams, family and community. Also, enhanced by their special lightening at night, they stand as attractive backgrounds for locals and visitors in relevant events in their lives.

  10. Prevalence and Molecular Characteristics of Waterborne Pathogen Legionella in Industrial Cooling Tower Environments.

    Science.gov (United States)

    Li, Lijie; Qin, Tian; Li, Yun; Zhou, Haijian; Song, Hongmei; Ren, Hongyu; Li, Liping; Li, Yongguang; Zhao, Dong

    2015-10-12

    Cooling towers are a source of Legionnaires' disease. It is important from a public health perspective to survey industrial cooling towers for the presence of Legionella. Prospective surveillance of the extent of Legionella pollution was conducted at factories in Shijiazhuang, China between March 2011 and September 2012. Overall, 35.7% of 255 industrial cooling tower water samples showed Legionella-positive, and their concentrations ranged from 100 Colony-Forming Units (CFU)/liter to 88,000 CFU/liter, with an average concentration of 9100 CFU/liter. A total of 121 isolates were obtained. All isolates were L. pneumophila, and the isolated serogroups included serogroups 1 (68 isolates, 56.2%), 6 (25, 20.7%), 5 (12, 9.9%), 8 (8, 6.6%), 3 (6, 5.0%) and 9 (2, 1.6%). All 121 isolates were analyzed by pulsed-field gel electrophoresis (PFGE) and 64 different patterns were obtained. All 121 isolates were analyzed sequence-based typing (SBT), a full 7-allele profile was obtained from 117 isolates. One hundred and seventeen isolates were divided into 49 sequence types. Two virulence genes, lvh and rtxA, are analyzed by polymerase chain reaction (PCR). 92.6% (112/121) and 98.3% (119/121) isolates carried lvh and rtxA respectively and 90.9% (110/121) of tested isolates carried both genes. Our results demonstrated high prevalence and genetic polymorphism of L. pneumophila in industrial cooling tower environments in Shijiazhang, China, and the SBT and virulence gene PCR results suggested that the isolates were pathogenic. Improved control and prevention strategies are urgently needed.

  11. Prevalence and Molecular Characteristics of Waterborne Pathogen Legionella in Industrial Cooling Tower Environments

    Directory of Open Access Journals (Sweden)

    Lijie Li

    2015-10-01

    Full Text Available Cooling towers are a source of Legionnaires’ disease. It is important from a public health perspective to survey industrial cooling towers for the presence of Legionella. Prospective surveillance of the extent of Legionella pollution was conducted at factories in Shijiazhuang, China between March 2011 and September 2012. Overall, 35.7% of 255 industrial cooling tower water samples showed Legionella-positive, and their concentrations ranged from 100 Colony-Forming Units (CFU/liter to 88,000 CFU/liter, with an average concentration of 9100 CFU/liter. A total of 121 isolates were obtained. All isolates were L. pneumophila, and the isolated serogroups included serogroups 1 (68 isolates, 56.2%, 6 (25, 20.7%, 5 (12, 9.9%, 8 (8, 6.6%, 3 (6, 5.0% and 9 (2, 1.6%. All 121 isolates were analyzed by pulsed-field gel electrophoresis (PFGE and 64 different patterns were obtained. All 121 isolates were analyzed sequence-based typing (SBT, a full 7-allele profile was obtained from 117 isolates. One hundred and seventeen isolates were divided into 49 sequence types. Two virulence genes, lvh and rtxA, are analyzed by polymerase chain reaction (PCR. 92.6% (112/121 and 98.3% (119/121 isolates carried lvh and rtxA respectively and 90.9% (110/121 of tested isolates carried both genes. Our results demonstrated high prevalence and genetic polymorphism of L. pneumophila in industrial cooling tower environments in Shijiazhang, China, and the SBT and virulence gene PCR results suggested that the isolates were pathogenic. Improved control and prevention strategies are urgently needed.

  12. A modular restoration tower for electric power line transmission

    Energy Technology Data Exchange (ETDEWEB)

    Nicolazzi, L.C.; Pereira, J.C.; Leonel, C.E.L.; Rocha, G.B.; Bianchezzi, V.; Mendes, F. [Universidade Federal Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica], Emails: lauro@grante.ufsc.br, jcarlos@grante.ufsc.br; Luz, R.L. [ELETROSUL Centrais Eletricas S.A., Florianopolis, SC (Brazil)], Email: rluz@eletrosul.gov.br

    2009-07-01

    The main target of this R and D project is to develop an restoration tower for electric energy lines transmission. Whereas these towers should present the main features like transport facility, easiest assembling associated with a low cost of manufacture, it was applied the single-column tower concepts supported by stays, modularized, framed and articulated at the base. The concepts used for this development was a design methodology. From the different definition situations of load, numerical models have been developed focusing the design to the best of structural element arrangements of its modules. Then, tests were performed in laboratory to determine the module structural performance for different work load situations. These tests served to identify inconsistencies in the numerical models and proposed adjustments in its design to improve its performance on the strength and stability. (author)

  13. Towards Cooling Tower Efficiency-An Energy Audit Approach

    Directory of Open Access Journals (Sweden)

    Long Su Weng Alwin

    2017-01-01

    Full Text Available This research studied the power generation trends from national grid and gas for a period of 4 years. Energy audit of critical systems like this is needful for optimal energy utilization. An energy audit was carried outon 6 industrial cooloing towers and their annual operating cost calculated. Variable speed drive suggested was installed and corresponding annual energy savings of 114,900 kWh/year cost saving of RM30,000 was achieved at a case study plant located in Malaysia. Cooling towers with smart systems was recommended for higher energy savings.

  14. Performance assessment of oxidants as a biocide for biofouling control in industrial seawater cooling towers

    KAUST Repository

    Al-Bloushi, Mohammed; Saththasivam, Jayaprakash; Jeong, Sanghyun; Amy, Gary L.; Leiknes, TorOve

    2017-01-01

    Biofouling can significantly hamper the efficiency of seawater cooling towers. The aim of this study was to investigate the effectiveness of alternative oxidants (i.e. ozone (O3) and chlorine dioxide (ClO2)) comparing with commonly being used chlorine in biofouling control. Effects of cycle of concentration, temperature and oxidant dosage along with residual decay and kinetics were studied. Even at lower oxidant dosage (total residual oxidant equivalent=0.1mg/L Cl2), ClO2 showed a better disinfection effect compared to chlorine and O3. Results of bench-scale studies will be helpful in the selection of appropriate oxidant for seawater cooling tower operation.

  15. Performance assessment of oxidants as a biocide for biofouling control in industrial seawater cooling towers

    KAUST Repository

    Al-Bloushi, Mohammed

    2017-10-14

    Biofouling can significantly hamper the efficiency of seawater cooling towers. The aim of this study was to investigate the effectiveness of alternative oxidants (i.e. ozone (O3) and chlorine dioxide (ClO2)) comparing with commonly being used chlorine in biofouling control. Effects of cycle of concentration, temperature and oxidant dosage along with residual decay and kinetics were studied. Even at lower oxidant dosage (total residual oxidant equivalent=0.1mg/L Cl2), ClO2 showed a better disinfection effect compared to chlorine and O3. Results of bench-scale studies will be helpful in the selection of appropriate oxidant for seawater cooling tower operation.

  16. Isolation of Legionella pneumophila from hospital cooling towers in Johor, Malaysia.

    Science.gov (United States)

    Abdul Samad, B H; Suhaili, M R; Baba, N; Rajasekaran, G

    2004-08-01

    Water-based cooling towers and their water supply at two hospitals in Johor were surveyed for the presence Legionella pneumophila. L. pneumophila were grown from 19 (76%) out of 25 collected water samples. One hospital cooling tower was contaminated with L. pneumophila serogroup 1.

  17. Laboratory Experiment and Numerical Analysis of a New Type of Solar Tower Efficiently Generating a Thermal Updraft

    Directory of Open Access Journals (Sweden)

    Yuji Ohya

    2016-12-01

    Full Text Available A new type of solar tower was developed through laboratory experiments and numerical analyses. The solar tower mainly consists of three components. The transparent collector area is an aboveground glass roof, with increasing height toward the center. Attached to the center of the inside of the collector is a vertical tower within which a wind turbine is mounted at the lower entry to the tower. When solar radiation heats the ground through the glass roof, ascending warm air is guided to the center and into the tower. A solar tower that can generate electricity using a simple structure that enables easy and less costly maintenance has considerable advantages. However, conversion efficiency from sunshine energy to mechanical turbine energy is very low. Aiming to improve this efficiency, the research project developed a diffuser-type tower instead of a cylindrical tower, and investigated a suitable diffuser shape for practical use. After changing the tower height and diffuser open angle, with a temperature difference between the ambient air aloft and within the collector, various diffuser tower shapes were tested by laboratory experiments and numerical analyses. As a result, it was found that a diffuser tower with a semi-open angle of 4° is an optimal shape, producing the fastest updraft at each temperature difference in both the laboratory experiments and numerical analyses. The relationships between thermal updraft speed and temperature difference and/or tower height were confirmed. It was found that the thermal updraft velocity is proportional to the square root of the tower height and/or temperature difference.

  18. A highly efficient Francis turbine designed for energy recovery in cooling towers

    Directory of Open Access Journals (Sweden)

    Daqing Zhou

    2015-03-01

    Full Text Available In China, cooling water entering cooling towers still retains surplus pressure between 39,240 and 147,150 Pa. In order to utilize this wasted energy, it is suggested that the surplus water energy can be harnessed to drive a type of hydroturbine installed in the inner platform of cooling tower and make the fan rotate via its coupled shafts. However, conventional hydroturbines are not suited for this job because of their low efficiency or unmatched rotating speed with that of the fan under the operating conditions of cooling towers. In this article, according to the requirements of turbine work environment in cooling towers, a new type of hydroturbine, Francis turbine with ultra-low specific speed (ns  = 50 m.kW, was designed to replace the fan motor in a cooling tower. Primarily, the shape, position, and number of runner blades were designed and optimized through theoretical analyses and computational fluid dynamics simulations. Additionally, metal elliptical volute and single-row ring guide vanes were applied to scale down the structural dimensions. Finally, the optimal scheme of the new Francis turbine was proven to have a high efficiency of 88% and good operation stability through testing of a physical model and can achieve the goal of harvesting renewable energy in the cooling tower.

  19. Wind Climate Analyses for a 61-M Tower in the Southeast

    International Nuclear Information System (INIS)

    Weber, A.H.

    2003-01-01

    The Savannah River Technology Center's (SRTC) Atmospheric Technologies Group (ATG) has operated nine 61-m tower sites including the Central Climatology (CC) tower which is located near the center of the Savannah River Site (SRS) since 1985. Data from the weather instruments on this tower have provided answers to questions involving risk analyses, dose studies, forecast verifications, and wind/temperature conditions during extreme events and planned tests. Most recently, data from these towers are being used for initial and boundary conditions for computationally intensive numerical simulations using mesoscale forecasting models that are run on a three-hourly basis by ATG for SRS and the surrounding vicinity. We found that a series of wind roses based on relatively short time scales (from two weeks to one hour) were a convenient method to depict the predominant wind speeds and directions at anemometer sites in the Southeast operated by the NWS. That report also revealed some interesting spatial and temporal relationships among thirteen NWS stations in the Carolinas, Georgia, and Florida. Our study here will focus on the CC tower to show changes in the wind speed and direction distributions with height during diurnal and annual cycles. This study will concentrate on mean wind speed and direction statistics

  20. Dwelling towers of Czech castles

    Czech Academy of Sciences Publication Activity Database

    Durdík, Tomáš

    2009-01-01

    Roč. 63, - (2009), s. 139-150 ISSN 1875-2896. [Meeting of Europa Nostra Scientific Council /44./. Kilkenny, 27.09.2008-02.10.2008] Institutional research plan: CEZ:AV0Z80020508 Keywords : castle * castellology * dwelling tower * donjon * keep * medieval archaeology * architecture * Bohemia * Middle Ages Subject RIV: AC - Archeology, Anthropology, Ethnology

  1. An exergy analysis on the performance of a counterflow wet cooling tower

    International Nuclear Information System (INIS)

    Muangnoi, Thirapong; Asvapoositkul, Wanchai; Wongwises, Somchai

    2007-01-01

    Cooling towers are used to extract waste heat from water to atmospheric air. An energy analysis is usually used to investigate the performance characteristics of cooling tower. However, the energy concept alone is insufficient to describe some important viewpoints on energy utilization. In this study, an exergy analysis is used to indicate exergy and exergy destruction of water and air flowing through the cooling tower. Mathematical model based on heat and mass transfer principle is developed to find the properties of water and air, which will be further used in exergy analysis. The model is validated against experimental data. It is noted from the results that the amount of exergy supplied by water is larger than that absorbed by air, because the system produces entropy. To depict the utilizable exergy between water and air, exergy of each working fluid along the tower are presented. The results show that water exergy decreases continuously from top to bottom. On the other hand, air exergy is expressed in terms of convective and evaporative heat transfer. Exergy of air via convective heat transfer initially loses at inlet and slightly recovers along the flow before leaving the tower. However, exergy of air via evaporative heat transfer is generally high and able to consume exergy supplied by water. Exergy destruction is defined as the difference between water exergy change and air exergy change. It reveals that the cooling processes due to thermodynamics irreversibility perform poorly at bottom and gradually improve along the height of the tower. The results show that the lowest exergy destruction is located at the top of the tower

  2. LaGuardia air traffic control tower.

    Science.gov (United States)

    2011-01-01

    To celebrate FAA and its LaGuardia Airport employees past, : present, and future this booklet outlines the airports history and accomplishments and includes copies of some of the photographs in the : air traffic control towers history g...

  3. Radiation Testing of PICA at the Solar Power Tower

    Science.gov (United States)

    White, Susan

    2010-01-01

    Sandia National Laboratory's Solar Power Tower was used to irradiate specimens of Phenolic Impregnated Carbon Ablator (PICA), in order to evaluate whether this thermal protection system material responded differently to potential shock layer radiative heating than to convective heating. Tests were run at 50, 100 and 150 Watts per square centimeter levels of concentrated solar radiation. Experimental results are presented both from spectral measurements on 1- 10 mm thick specimens of PICA, as well as from in-depth temperature measurements on instrumented thicker test specimens. Both spectral measurements and measured in-depth temperature profiles showed that, although it is a porous, low-density material, PICA does not exhibit problematic transparency to the tested high levels of NIR radiation, for all pragmatic cm-to-inch scale thicknesses. PICA acted as a surface absorber to efficiently absorb the incident visible and near infrared incident radiation in the top 2 millimeter layer in the Solar Power Tower tests up to 150 Watts per square centimeter.

  4. Dimensions of Air Traffic Control Tower Information Needs: From Information Requests to Display Design

    Science.gov (United States)

    Durso, Francis T.; Johnson, Brian R.; Crutchfield, Jerry M.

    2010-01-01

    In an effort to determine the information needs of tower air traffic controllers, instructors from the Federal Aviation Administration's Academy in Oklahoma City were asked to control traffic in a high-fidelity tower cab simulator. Information requests were made apparent by eliminating access to standard tower information sources. Instead,…

  5. Research Based on the Acoustic Emission of Wind Power Tower Drum Dynamic Monitoring Technology

    Science.gov (United States)

    Zhang, Penglin; Sang, Yuan; Xu, Yaxing; Zhao, Zhiqiang

    Wind power tower drum is one of the key components of the wind power equipment. Whether the wind tower drum performs safety directly affects the efficiency, life, and performance of wind power equipment. Wind power tower drum in the process of manufacture, installation, and operation may lead to injury, and the wind load and gravity load and long-term factors such as poor working environment under the action of crack initiation or distortion, which eventually result in the instability or crack of the wind power tower drum and cause huge economic losses. Thus detecting the wind power tower drum crack damage and instability is especially important. In this chapter, acoustic emission is used to monitor the whole process of wind power tower drum material Q345E steel tensile test at first, and processing and analysis tensile failure signal of the material. And then based on the acoustic emission testing technology to the dynamic monitoring of wind power tower drum, the overall detection and evaluation of the existence of active defects in the whole structure, and the acoustic emission signals collected for processing and analysis, we could preliminarily master the wind tower drum mechanism of acoustic emission source. The acoustic emission is a kind of online, efficient, and economic method, which has very broad prospects for work. The editorial committee of nondestructive testing qualification and certification of personnel teaching material of science and technology industry of national defense, "Acoustic emission testing" (China Machine Press, 2005.1).

  6. Restoration of the Serranos Towers in Valencia.

    Directory of Open Access Journals (Sweden)

    Camilla Mileto

    2003-12-01

    Full Text Available The recent restoration of the emblematic Serranos Towers carried out by an interdisciplinary team of specialists was an excuse to delve into the history and masonry of the towers, from their initial building and use as a prison to the restorations works practised in the 19th century and subsequent repairs. The cleaning of the walls permitted a direct study of the masonry, which provided a great deal of information that complemented the rigorous historical investigation. The maintenance scheme planned for the future is an interesting proposal, where good sense prevails over improvisation, so often a reality in the restoration of monuments today.

  7. Cooling tower water circuits with raceways

    International Nuclear Information System (INIS)

    Nicollet, G.

    1981-02-01

    Two physical models built at the National Hydraulics Laboratory in Chatou have led to the determination of the design of the works. This new design economizes 4 to 5 MW on pumping power for each cooling tower [fr

  8. Dry cooling towers - the Schmehausen example

    International Nuclear Information System (INIS)

    Weber, P.

    1977-01-01

    In a prototype, there are often problems which require special static, constructive, and assembling measures for their solution. In the case of the Schmehausen dry cooling tower, the demands on the assembling technology are particularly high. (orig.) [de

  9. Performance Evaluation on Transmission Tower-Line System with Passive Friction Dampers Subjected to Wind Excitations

    Directory of Open Access Journals (Sweden)

    Bo Chen

    2015-01-01

    Full Text Available The vibration control and performance evaluation on a transmission-tower line system by using friction dampers subjected to wind excitations are carried out in this study. The three-dimensional finite element (FE model of a transmission tower is firstly constructed. A two-dimensional lumped mass model of a transmission tower is developed for dynamic analysis. The analytical model of transmission tower-line system is proposed by taking the dynamic interaction between the tower and the transmission lines into consideration. The mechanical model of passive friction damper is presented by involving the effects of damper axial stiffness. The equation of motion of the transmission tower-line system incorporated with the friction dampers disturbed by wind excitations is established. A real transmission tower-line system is taken as an example to examine the feasibility and reliability of the proposed control approach. An extensive parameter study is carried out to find the optimal parameters of friction damper and to assess the effects of slipping force axial stiffness and hysteresis loop on control performance. The work on an example structure indicates that the application of friction dampers with optimal parameters could significantly reduce wind-induced responses of the transmission tower-line system.

  10. Alternative geometry for cylindrical natural draft cooling tower with higher cooling efficiency under crosswind condition

    International Nuclear Information System (INIS)

    Goodarzi, M.; Ramezanpour, R.

    2014-01-01

    Highlights: • Alternative cross sections for natural draft cooling tower were proposed. • Numerical solution was applied to study thermal and hydraulic performances. • Thermal and hydraulic performances were assessed by comparative parameters. • Cooling tower with elliptical cross section had better thermal performance under crosswind. • It could successfully used at the regions with invariant wind direction. - Abstract: Cooling efficiency of a natural draft dry cooling tower may significantly decrease under crosswind condition. Therefore, many researchers attempted to improve the cooling efficiency under this condition by using structural or mechanical facilities. In this article, alternative shell geometry with elliptical cross section is proposed for this type of cooling tower instead of usual shell geometry with circular cross section. Thermal performance and cooling efficiency of the two types of cooling towers are numerically investigated. Numerical simulations show that cooling tower with elliptical cross section improves the cooling efficiency compared to the usual type with circular cross section under high-speed wind moving normal to the longitudinal diameter of the elliptical cooling tower

  11. Experimental study on the thermal performance of a mechanical cooling tower with different drift eliminators

    International Nuclear Information System (INIS)

    Lucas, M.; Martinez, P.J.; Viedma, A.

    2009-01-01

    Cooling towers are equipment devices commonly used to dissipate heat from power generation units, water-cooled refrigeration, air conditioning and industrial processes. Water drift emitted from cooling towers is objectionable for several reasons, mainly due to human health hazards. It is common practice to fit drift eliminators to cooling towers in order to minimize water loss from the system. It is foreseeable that the characteristics of the installed drift eliminators, like their pressure drop, affect the thermal performance of the cooling tower. However, no references regarding this fact have been found in the reviewed bibliography. This paper studies the thermal performance of a forced draft counter-flow wet cooling tower fitted with different drift eliminators for a wide range of air and water mass flow rates. The data registered in the experimental set-up were employed to obtain correlations of the tower characteristic, which defines the cooling tower's thermal performance. The outlet water temperature predicted by these correlations was compared with the experimentally registered values obtaining a maximum difference of ±3%

  12. Study of blade-tower interaction using a 2D Navier-Stokes solver

    Energy Technology Data Exchange (ETDEWEB)

    Bertagnolio, F [Risoe National Lab., Wind Energy and Atmospheric Physics Dept., Roskilde (Denmark)

    1999-03-01

    The aim of this work is to model and study the dynamic interaction of the fluid flow with the structure which occurs when the blades of a wind turbine are passing in front of (or possibly behind) the tower. In order to capture the whole complexity of this phenomenon, the full unsteady Navier-Stokes equations for an incompressible fluid are used as a model. A new computational technique is described. For the sake of simplicity, we restrict ourselves to two-dimensional cases. The present methodology is illustrated by the computation of a wind turbine-like configuration in a periodic domain. (au)

  13. Optimization of cooling tower performance analysis using Taguchi method

    OpenAIRE

    Ramkumar Ramakrishnan; Ragupathy Arumugam

    2013-01-01

    This study discuss the application of Taguchi method in assessing maximum cooling tower effectiveness for the counter flow cooling tower using expanded wire mesh packing. The experiments were planned based on Taguchi’s L27 orthogonal array .The trail was performed under different inlet conditions of flow rate of water, air and water temperature. Signal-to-noise ratio (S/N) analysis, analysis of variance (ANOVA) and regression were carried out in order to determine the effects of process...

  14. Legionella in industrial cooling towers: monitoring and control strategies.

    Science.gov (United States)

    Carducci, A; Verani, M; Battistini, R

    2010-01-01

    Legionella contamination of industrial cooling towers has been identified as the cause of sporadic cases and outbreaks of legionellosis among people living nearby. To evaluate and control Legionella contamination in industrial cooling tower water, microbiological monitoring was carried out to determine the effectiveness of the following different disinfection treatments: (i) continuous chlorine concentration of 0.01 ppm and monthly chlorine shock dosing (5 ppm) on a single cooling tower; (ii) continuous chlorine concentration of 0.4 ppm and monthly shock of biocide P3 FERROCID 8580 (BKG Water Solution) on seven towers. Legionella spp. and total bacterial count (TBC) were determined 3 days before and after each shock dose. Both strategies demonstrated that when chlorine was maintained at low levels, the Legionella count grew to levels above 10(4) CFU l(-1) while TBC still remained above 10(8 )CFU l(-1). Chlorine shock dosing was able to eliminate bacterial contamination, but only for 10-15 days. Biocide shock dosing was also insufficient to control the problem when the disinfectant concentration was administered at only one point in the plant and at the concentration of 30 ppm. On the other hand, when at a biocide concentration of 30 or 50 ppm was distributed throughout a number of points, depending on the plant hydrodynamics, Legionella counts decreased significantly and often remained below the warning limit. Moreover, the contamination of water entering the plant and the presence of sediment were also important factors for Legionella growth. For effective decontamination of outdoor industrial cooling towers, disinfectants should be distributed in a targeted way, taking into account the possible sources of contamination. The data of the research permitted to modify the procedure of disinfection for better reduce the water and aerosol contamination and consequently the exposure risk.

  15. A Large Community Outbreak of Legionnaires' Disease Associated With a Cooling Tower in New York City, 2015.

    Science.gov (United States)

    Weiss, Don; Boyd, Christopher; Rakeman, Jennifer L; Greene, Sharon K; Fitzhenry, Robert; McProud, Trevor; Musser, Kimberlee; Huang, Li; Kornblum, John; Nazarian, Elizabeth J; Fine, Annie D; Braunstein, Sarah L; Kass, Daniel; Landman, Keren; Lapierre, Pascal; Hughes, Scott; Tran, Anthony; Taylor, Jill; Baker, Deborah; Jones, Lucretia; Kornstein, Laura; Liu, Boning; Perez, Rodolfo; Lucero, David E; Peterson, Eric; Benowitz, Isaac; Lee, Kristen F; Ngai, Stephanie; Stripling, Mitch; Varma, Jay K

    Infections caused by Legionella are the leading cause of waterborne disease outbreaks in the United States. We investigated a large outbreak of Legionnaires' disease in New York City in summer 2015 to characterize patients, risk factors for mortality, and environmental exposures. We defined cases as patients with pneumonia and laboratory evidence of Legionella infection from July 2 through August 3, 2015, and with a history of residing in or visiting 1 of several South Bronx neighborhoods of New York City. We describe the epidemiologic, environmental, and laboratory investigation that identified the source of the outbreak. We identified 138 patients with outbreak-related Legionnaires' disease, 16 of whom died. The median age of patients was 55. A total of 107 patients had a chronic health condition, including 43 with diabetes, 40 with alcoholism, and 24 with HIV infection. We tested 55 cooling towers for Legionella, and 2 had a strain indistinguishable by pulsed-field gel electrophoresis from 26 patient isolates. Whole-genome sequencing and epidemiologic evidence implicated 1 cooling tower as the source of the outbreak. A large outbreak of Legionnaires' disease caused by a cooling tower occurred in a medically vulnerable community. The outbreak prompted enactment of a new city law on the operation and maintenance of cooling towers. Ongoing surveillance and evaluation of cooling tower process controls will determine if the new law reduces the incidence of Legionnaires' disease in New York City.

  16. A Large Community Outbreak of Legionnaires’ Disease Associated With a Cooling Tower in New York City, 2015

    Science.gov (United States)

    Boyd, Christopher; Rakeman, Jennifer L.; Greene, Sharon K.; Fitzhenry, Robert; McProud, Trevor; Musser, Kimberlee; Huang, Li; Kornblum, John; Nazarian, Elizabeth J.; Fine, Annie D.; Braunstein, Sarah L.; Kass, Daniel; Landman, Keren; Lapierre, Pascal; Hughes, Scott; Tran, Anthony; Taylor, Jill; Baker, Deborah; Jones, Lucretia; Kornstein, Laura; Liu, Boning; Perez, Rodolfo; Lucero, David E.; Peterson, Eric; Benowitz, Isaac; Lee, Kristen F.; Ngai, Stephanie; Stripling, Mitch; Varma, Jay K.

    2017-01-01

    Objectives: Infections caused by Legionella are the leading cause of waterborne disease outbreaks in the United States. We investigated a large outbreak of Legionnaires’ disease in New York City in summer 2015 to characterize patients, risk factors for mortality, and environmental exposures. Methods: We defined cases as patients with pneumonia and laboratory evidence of Legionella infection from July 2 through August 3, 2015, and with a history of residing in or visiting 1 of several South Bronx neighborhoods of New York City. We describe the epidemiologic, environmental, and laboratory investigation that identified the source of the outbreak. Results: We identified 138 patients with outbreak-related Legionnaires’ disease, 16 of whom died. The median age of patients was 55. A total of 107 patients had a chronic health condition, including 43 with diabetes, 40 with alcoholism, and 24 with HIV infection. We tested 55 cooling towers for Legionella, and 2 had a strain indistinguishable by pulsed-field gel electrophoresis from 26 patient isolates. Whole-genome sequencing and epidemiologic evidence implicated 1 cooling tower as the source of the outbreak. Conclusions: A large outbreak of Legionnaires’ disease caused by a cooling tower occurred in a medically vulnerable community. The outbreak prompted enactment of a new city law on the operation and maintenance of cooling towers. Ongoing surveillance and evaluation of cooling tower process controls will determine if the new law reduces the incidence of Legionnaires’ disease in New York City. PMID:28141970

  17. Mapping carbon flux uncertainty and selecting optimal locations for future flux towers in the Great Plains

    Science.gov (United States)

    Gu, Yingxin; Howard, Daniel M.; Wylie, Bruce K.; Zhang, Li

    2012-01-01

    Flux tower networks (e. g., AmeriFlux, Agriflux) provide continuous observations of ecosystem exchanges of carbon (e. g., net ecosystem exchange), water vapor (e. g., evapotranspiration), and energy between terrestrial ecosystems and the atmosphere. The long-term time series of flux tower data are essential for studying and understanding terrestrial carbon cycles, ecosystem services, and climate changes. Currently, there are 13 flux towers located within the Great Plains (GP). The towers are sparsely distributed and do not adequately represent the varieties of vegetation cover types, climate conditions, and geophysical and biophysical conditions in the GP. This study assessed how well the available flux towers represent the environmental conditions or "ecological envelopes" across the GP and identified optimal locations for future flux towers in the GP. Regression-based remote sensing and weather-driven net ecosystem production (NEP) models derived from different extrapolation ranges (10 and 50%) were used to identify areas where ecological conditions were poorly represented by the flux tower sites and years previously used for mapping grassland fluxes. The optimal lands suitable for future flux towers within the GP were mapped. Results from this study provide information to optimize the usefulness of future flux towers in the GP and serve as a proxy for the uncertainty of the NEP map.

  18. Interception and retention of simulated cooling tower drift by vegetation

    International Nuclear Information System (INIS)

    Taylor, F.G. Jr.; Parr, P.D.

    1978-01-01

    A key issue concerning environmental impacts from cooling tower operation is the interception of drift by vegetation and the efficiency of plants in retaining the residue scavenged from the atmosphere. Chromated drift water, typical of the cooling towers of the Department of Energy's uranium enrichment facilities at Oak Ridge, Tennessee, was prepared using radio-labelled chromium. A portable aerosol generator was used to produce a spectrum of droplets with diameters (100 to 1300 μ) characteristic of cooling towers using state-of-the-art drift eliminators. Efficiency of interception by foliage varied according to leaf morphology with yellow poplar seedlings intercepting 72% of the deposition mass in contrast to 45% by loblolly pine and 24% by fescue grass. Retention patterns of intercepted deposition consisted of a short-time component (0 to 3 days) and a long-time component (3 to 63 days). Retention times, estimated from the regression equation of the long component, indicated that drift contamination from any deposition event may persist from between 8 and 12 weeks. In field situations adjacent to cooling towers, the average annual concentration of drift on vegetation at any distance remains relatively constant, with losses from weathering being compensated by chronic deposition

  19. The WACMOS-ET project – Part 1: Tower-scale evaluation of four remote sensing-based evapotranspiration algorithms

    KAUST Repository

    Michel, D.

    2015-10-20

    The WACMOS-ET project has compiled a forcing data set covering the period 2005–2007 that aims to maximize the exploitation of European Earth Observations data sets for evapotranspiration (ET) estimation. The data set was used to run 4 established ET algorithms: the Priestley–Taylor Jet Propulsion Laboratory model (PT-JPL), the Penman–Monteith algorithm from the MODIS evaporation product (PM-MOD), the Surface Energy Balance System (SEBS) and the Global Land Evaporation Amsterdam Model (GLEAM). In addition, in-situ meteorological data from 24 FLUXNET towers was used to force the models, with results from both forcing sets compared to tower-based flux observations. Model performance was assessed across several time scales using both sub-daily and daily forcings. The PT-JPL model and GLEAM provide the best performance for both satellite- and tower-based forcing as well as for the considered temporal resolutions. Simulations using the PM-MOD were mostly underestimated, while the SEBS performance was characterized by a systematic overestimation. In general, all four algorithms produce the best results in wet and moderately wet climate regimes. In dry regimes, the correlation and the absolute agreement to the reference tower ET observations were consistently lower. While ET derived with in situ forcing data agrees best with the tower measurements (R2 = 0.67), the agreement of the satellite-based ET estimates is only marginally lower (R2 = 0.58). Results also show similar model performance at daily and sub-daily (3-hourly) resolutions. Overall, our validation experiments against in situ measurements indicate that there is no single best-performing algorithm across all biome and forcing types. An extension of the evaluation to a larger selection of 85 towers (model inputs re-sampled to a common grid to facilitate global estimates) confirmed the original findings.

  20. Study on Remote Monitoring System of Crossing and Spanning Tangent Tower

    Science.gov (United States)

    Chen, Da-bing; Zhang, Nai-long; Zhang, Meng-ge; Wang, Ze-hua; Zhang, Yan

    2017-05-01

    In order to grasp the vibration state of overhead transmission line and ensure the operational security of transmission line, the remote monitoring system of crossing and spanning tangent tower was studied. By use of this system, the displacement, velocity and acceleration of the tower, and the local weather data are collected automatically, displayed on computer of remote monitoring centre through wireless network, real-time collection and transmission of vibration signals are realized. The applying results show that the system is excellent in reliability and accuracy and so on. The system can be used to remote monitoring of transmission tower of UHV power transmission lines and in large spanning areas.

  1. Cost-benefit of the bubble tower concept as a containment passive safety system

    International Nuclear Information System (INIS)

    Iotti, R.C.; Bardach, H.; Shin, J.J.; Parnes, M.J.

    1994-01-01

    Containment system integrity for both PWRs and BWRs can be assured by passive measures highlighted the use of an accessory Bubble Tower. The utilization of the Bubble Tower precludes the possibility of containment overpressurization. From the thermodynamic standpoint, the Bubble Tower is simply water column of about 120 ft. height attached to the containment and connected to the air space above the suppression pool of a BWR, or a PWR In-containment Refueling Water Storage Tank. From the radiological protection standpoint, the Bubble Tower is a water column sufficient to effect decontamination factors of at least 100 for nuclide species other than the noble gases, and with the addition of organic solubilizers sufficient to effect decontamination factors of at least 10 iodides and at least 100 for other nuclide species. When containment steam or noncondensable gas passes through the Bubble Tower, a significant fraction of the radionuclides is absorbed by the water column. When a cost-benefit dose evaluation is performed relative to the utilization of a Bubble Tower, even under conditions where the dollars per man-rem is taken as $1000, the results are favorable. They are substantially more favorable when the dollars per man-rem is taken as $5000 or $10,000 as are the current trends. (author)

  2. Evaluating the Effectiveness of Wildlife Detection and Observation Technologies at a Solar Power Tower Facility.

    Science.gov (United States)

    Diehl, Robert H; Valdez, Ernest W; Preston, Todd M; Wellik, Michael J; Cryan, Paul M

    2016-01-01

    Solar power towers produce electrical energy from sunlight at an industrial scale. Little is known about the effects of this technology on flying animals and few methods exist for automatically detecting or observing wildlife at solar towers and other tall anthropogenic structures. Smoking objects are sometimes observed co-occurring with reflected, concentrated light ("solar flux") in the airspace around solar towers, but the identity and origins of such objects can be difficult to determine. In this observational pilot study at the world's largest solar tower facility, we assessed the efficacy of using radar, surveillance video, and insect trapping to detect and observe animals flying near the towers. During site visits in May and September 2014, we monitored the airspace surrounding towers and observed insects, birds, and bats under a variety of environmental and operational conditions. We detected and broadly differentiated animals or objects moving through the airspace generally using radar and near solar towers using several video imaging methods. Video revealed what appeared to be mostly small insects burning in the solar flux. Also, we occasionally detected birds flying in the solar flux but could not accurately identify birds to species or the types of insects and small objects composing the vast majority of smoking targets. Insect trapping on the ground was somewhat effective at sampling smaller insects around the tower, and presence and abundance of insects in the traps generally trended with radar and video observations. Traps did not tend to sample the larger insects we sometimes observed flying in the solar flux or found dead on the ground beneath the towers. Some of the methods we tested (e.g., video surveillance) could be further assessed and potentially used to automatically detect and observe flying animals in the vicinity of solar towers to advance understanding about their effects on wildlife.

  3. Evaluating the effectiveness of wildlife detection and observation technologies at a solar power tower facility

    Science.gov (United States)

    Diehl, Robert H.; Valdez, Ernest W.; Preston, Todd M.; Wellik, Mike J.; Cryan, Paul

    2016-01-01

    Solar power towers produce electrical energy from sunlight at an industrial scale. Little is known about the effects of this technology on flying animals and few methods exist for automatically detecting or observing wildlife at solar towers and other tall anthropogenic structures. Smoking objects are sometimes observed co-occurring with reflected, concentrated light (“solar flux”) in the airspace around solar towers, but the identity and origins of such objects can be difficult to determine. In this observational pilot study at the world’s largest solar tower facility, we assessed the efficacy of using radar, surveillance video, and insect trapping to detect and observe animals flying near the towers. During site visits in May and September 2014, we monitored the airspace surrounding towers and observed insects, birds, and bats under a variety of environmental and operational conditions. We detected and broadly differentiated animals or objects moving through the airspace generally using radar and near solar towers using several video imaging methods. Video revealed what appeared to be mostly small insects burning in the solar flux. Also, we occasionally detected birds flying in the solar flux but could not accurately identify birds to species or the types of insects and small objects composing the vast majority of smoking targets. Insect trapping on the ground was somewhat effective at sampling smaller insects around the tower, and presence and abundance of insects in the traps generally trended with radar and video observations. Traps did not tend to sample the larger insects we sometimes observed flying in the solar flux or found dead on the ground beneath the towers. Some of the methods we tested (e.g., video surveillance) could be further assessed and potentially used to automatically detect and observe flying animals in the vicinity of solar towers to advance understanding about their effects on wildlife.

  4. Reuse of refinery's tertiary-treated wastewater in cooling towers: microbiological monitoring.

    Science.gov (United States)

    Dos Santos, Vera Lúcia; Veiga, Andréa Azevedo; Mendonça, Rafael Silva; Alves, Andrea Lima; Pagnin, Sérgio; Santiago, Vânia M J

    2015-02-01

    The study was planned to quantify the distribution of bacteria between bulk water and biofilm formed on different materials in an industrial scale cooling tower system of an oil refinery operating with clarified and chlorinated freshwater (CCW) or chlorinated tertiary effluent (TRW) as makeup water. The sessile and planktonic heterotrophic bacteria and Pseudomonas aeruginosa densities were significantly higher in the cooling tower supplied with clarified and chlorinated freshwater (CTCW) (p towers, the biofilm density was higher on the surface of glass slides and stainless steel coupons than on the surface of carbon steel coupons. The average corrosion rates of carbon steel coupons (0.4-0.8 millimeters per year (mpy)) and densities of sessile (12-1.47 × 10(3) colony-forming unit (CFU) cm(-1)) and planktonic (0-2.36 × 10(3) CFU mL(-1)) microbiota remained below of the maximum values of reference used by water treatment companies as indicative of efficient microbial control. These data indicate that the strategies of the water treatment station (WTS) (free chlorine) and industrial wastewater treatment station (IWTS) followed by reverse electrodialysis system (RES) (free chlorine plus chloramine) were effective for the microbiological control of the two makeup water sources.

  5. Control of droplet size in rain-zone in wet cooling tower

    Directory of Open Access Journals (Sweden)

    Vitkovicova Rut

    2018-01-01

    Full Text Available The performance of the wet cooling tower is significantly affected by the droplet size occurring in the rain zone. In order to effectively manage the size of these droplets, it was necessary to experimentally determine the effect of the fills of the cooling towers on droplets. Five types of cooling fillers were used for experimental measurements: 3 film fills and 2 splash fills - trickle and grid. Drop size measurements were performed using the LIF method. Histograms of droplets size were obtained from measured droplet sizes under each fill, and for each fill, the Sauter droplet diameter was then calculated. According to a theoretical analysis of a breakdown of droplets, the combinations of some fills and the effect of their surface treatment on the droplet diameter were then measured for comparison.

  6. Investigation of Airflow Patterns in a New Design of Wind Tower with a Wetted Surface

    Directory of Open Access Journals (Sweden)

    Madjid Soltani

    2018-04-01

    Full Text Available Passive cooling systems, such as wind towers, can help to reduce energy consumption in buildings and at the same time reduce greenhouse gas (GHG emissions. Wind towers can naturally ventilate buildings and also can create enhanced thermal comfort for occupants during the warm months. This study proposes a modern wind tower design with a moistened pad. The new design includes a fixed column, a rotating and movable head, an air opening with a screen, and two windows at the end of the column. The wind tower can be installed on roof-tops to take advantage of ambient airflow. The wind tower’s head can be controlled manually or automatically to capture optimum wind velocity based on desired thermal condition. To maximize its performance, a small pump was considered to circulate and spray water on an evaporative cooling pad. A computational fluid dynamics (CFD simulation of airflow around and inside the proposed wind tower is conducted to analyze the ventilation performance of this new design of wind tower. Thereby, the velocity, total pressure, and pressure coefficient distributions around and within the wind tower for different wind velocities are examined. The simulation results illustrate that the new wind tower design with a moistened pad can be a reasonable solution to improve naturally the thermal comfort of buildings in hot and dry climates.

  7. Collapse and pull - down analysis of high voltage electricity transmission towers subjected to cyclonic wind

    International Nuclear Information System (INIS)

    Ahmed, Ammar; Arthur, Craig; Edwards, Mark

    2010-01-01

    Bulk electricity transmission lines are linear assets that can be very exposed to wind effects, particularly where they traverse steep topography or open coastal terrain in cyclonic regions. Interconnected nature of the lattice type towers and conductors also, present complex vulnerabilities. These relate to the direction of wind attack to the conductors and the cascading failure mechanisms in which the failure of a single tower has cascading effects on neighbouring towers. Such behaviour is exacerbated by the finely tuned nature of tower design which serves to minimize cost and reserve strength at design wind speeds. There is a clear need to better quantify the interdependent vulnerabilities of these critical infrastructure assets in the context of the severe wind hazard. This paper presents a novel methodology developed for the Critical Infrastructure Protection Modelling and Analysis (CIPMA) capability for assessing local wind speeds and the likelihood of tower failure for a range of transmission tower and conductor types. CIPMA is a program managed by the Federal Attorney-General's Department and Geoscience Australia is leading the technical development. The methodology then involves the development of heuristically derived vulnerability models that are consistent with Australian industry experience and full-scale static tower testing results, considering isolated tower loss along with three interdependent failure mechanisms to give overall likelihoods of failure.

  8. Optimization of Structural Design for Sustainable Construction of Transmission Tower Based on Topographical Algorithm

    International Nuclear Information System (INIS)

    Muda, Zakaria Che; Thiruchelvam, Sivadass; Mustapha, Kamal Nasharuddin; Omar, Rohayu Che; Usman, Fathoni; Alam, Md Ashrafu

    2013-01-01

    Optimization of transmission tower structures is traditionally based on either optimization of members sizes with fixed topographical shape or based on structural analysis modelling strategies without taking cognizance of fabrication and constructability issue facing the contractors . This paper look into an integrated optimum design approach strategies whereby size, shape and topology are combined together with the fabrication issues in the construction of the transmission tower. The topographical algorithm is based on changing the inclination degree of the legs of the tower at first with optimum individual members sizing and later rationalized member sizes are performed through member groupings for the ease fabrication and construction of the transmission tower. The optimum weight using topographical algorithm obtained for the transmission tower is 10,924 kg for singular members and 18,430 kg for element grouping at 10° inclination angle.

  9. Hospital-acquired legionellosis originating from a cooling tower during a period of thermal inversion.

    Science.gov (United States)

    Engelhart, Steffen; Pleischl, Stefan; Lück, Christian; Marklein, Günter; Fischnaller, Edith; Martin, Sybille; Simon, Arne; Exner, Martin

    2008-07-01

    A case of hospital-acquired legionellosis occurred in a 75-year-old male patient who underwent surgery due to malignant melanoma. Legionellosis was proven by culture of Legionella pneumophila serogroup 1 from bronchoalveolar lavage (BAL) fluid. Being a chronic smoker the patient used to visit the sickroom balcony that was located about 90 m to the west of a hospital cooling tower. Routine cooling tower water samples drawn during the presumed incubation period revealed 1.0x10(4) CFU/100 ml (L. pneumophila serogroup 1). One of three isolates from the cooling tower water matched the patient's isolate by monoclonal antibody (mab)- and genotyping (sequence-based typing). Horizontal transport of cooling tower aerosols probably was favoured by meteorological conditions with thermal inversion. The case report stresses the importance of routine maintenance and microbiological control of hospital cooling towers.

  10. An integrated reliability-based design optimization of offshore towers

    International Nuclear Information System (INIS)

    Karadeniz, Halil; Togan, Vedat; Vrouwenvelder, Ton

    2009-01-01

    After recognizing the uncertainty in the parameters such as material, loading, geometry and so on in contrast with the conventional optimization, the reliability-based design optimization (RBDO) concept has become more meaningful to perform an economical design implementation, which includes a reliability analysis and an optimization algorithm. RBDO procedures include structural analysis, reliability analysis and sensitivity analysis both for optimization and for reliability. The efficiency of the RBDO system depends on the mentioned numerical algorithms. In this work, an integrated algorithms system is proposed to implement the RBDO of the offshore towers, which are subjected to the extreme wave loading. The numerical strategies interacting with each other to fulfill the RBDO of towers are as follows: (a) a structural analysis program, SAPOS, (b) an optimization program, SQP and (c) a reliability analysis program based on FORM. A demonstration of an example tripod tower under the reliability constraints based on limit states of the critical stress, buckling and the natural frequency is presented.

  11. An integrated reliability-based design optimization of offshore towers

    Energy Technology Data Exchange (ETDEWEB)

    Karadeniz, Halil [Faculty of Civil Engineering and Geosciences, Delft University of Technology, Delft (Netherlands)], E-mail: h.karadeniz@tudelft.nl; Togan, Vedat [Department of Civil Engineering, Karadeniz Technical University, Trabzon (Turkey); Vrouwenvelder, Ton [Faculty of Civil Engineering and Geosciences, Delft University of Technology, Delft (Netherlands)

    2009-10-15

    After recognizing the uncertainty in the parameters such as material, loading, geometry and so on in contrast with the conventional optimization, the reliability-based design optimization (RBDO) concept has become more meaningful to perform an economical design implementation, which includes a reliability analysis and an optimization algorithm. RBDO procedures include structural analysis, reliability analysis and sensitivity analysis both for optimization and for reliability. The efficiency of the RBDO system depends on the mentioned numerical algorithms. In this work, an integrated algorithms system is proposed to implement the RBDO of the offshore towers, which are subjected to the extreme wave loading. The numerical strategies interacting with each other to fulfill the RBDO of towers are as follows: (a) a structural analysis program, SAPOS, (b) an optimization program, SQP and (c) a reliability analysis program based on FORM. A demonstration of an example tripod tower under the reliability constraints based on limit states of the critical stress, buckling and the natural frequency is presented.

  12. A construction method of reinforced-concrete very high stacks and natural draft cooling towers

    International Nuclear Information System (INIS)

    Miyamoto, Takao; Hosokawa, Osamu

    1978-01-01

    The new Shimizu flex-lip system was developed by the Shimizu Construction Co., Ltd. for constructing very high (about 200 m) towers made of reinforced concrete. Utilizing this system, towers of any shape, circular, triangular, square and polygonal, can be constructed. The wall thickness can be varied from 200 mm to 1 m. The diameter of towers can be enlarged from 3 m to any valve and the inclination of tower walls can be designed in any way between +1/5 and -1/5. The advantage of this system is to use the jack down mechanism, to test concrete strength without sampling, to reduce the connections of reinforcing steel bars and to adopt the continuous, and to use automatic measuring system using laser for checking up positional error. The design and analysis of high tower structures were systemized and automated with the development of the flex-lip construction method. The several past records of having applied this method to industrial areas are shown. As for natural draft cooling towers, the Shimizu jump-up system has been studied for the cooling water capacity of 60,000 m 3 /h. The towers are 120 m high, 110 m in diameter at the bottom and 65 m in diameter at the top. The advantage of this construction method, the plan of concrete jump-up and the construction test are explained. (Nakai, Y.)

  13. An investigation of digital creative of the Chih-Kan-Tower

    Science.gov (United States)

    Lin, Hsiao-Man; Lu, Fang-Chuan; Tsai, J. C.

    2011-10-01

    Utilization of the developed digital archives could stimulate the spirit of humanity and creativity, especially for Chinese people in Taiwan, and also satisfy cultural passion and pursuit of knowledge. Furthermore, this study creates simulated informational digital archives of Tainan Chih-Kan-Tower in order to effectively integrate the multiple unique and useful historical records and information. Examples include Chih-Kan- Tower's historical change and Taiwan's ancient map. The study also creates a three dimension (3D) visualization and a two dimension (2D) motion video which, provided by Google Earth, can enhance the experience of media interaction, improve cultural interaction as well as multi-level knowledge by better understanding . With further research on application of digital archives in multiple facets, the finally developed digital archives have great potential to become a very useful tool to promote the most valuable cultural heritage in the nation.

  14. Chemical basics of spray tower's development for separation of CO{sub 2} from flue gases. New process. Known technology; Chemische Grundlagen der Entwicklung eines Spruehwaeschers zur Abtrennung von CO{sub 2} aus Rauchgasen. Neues Verfahren. Bekannte Technik

    Energy Technology Data Exchange (ETDEWEB)

    Brechtel, Kevin; Schaeffer, Anke; Galindo Cifre, Paula; Seyboth, Oliver [Stuttgart Univ. (Germany). Abt. Brennstoffe und Rauchgasreinigung; Scheffknecht, Guenter [Stuttgart Univ. (DE). Inst. fuer Feuerungs- und Kraftwerkstechnik (IFK)

    2011-07-01

    Post-combustion capture by amine scrubbing is one technology for CO{sub 2} capture from flue gases. The basic process is well known from industrial applications and is suitable for retrofitting to power plants. Besides the development of new solvents, the IFK is currently investigating the use of open spray towers as alternative concepts to packed columns. Therefore, different operational parameters for several solvents have been determined within lab scale tests. Based on these data and the knowledge from wet FGD systems show that the use of spray towers for CO{sub 2} capture is a promising alternative. (orig.)

  15. A Model for Interpreting High-Tower CO2 Concentration Records for the Surface Carbon Balance Information

    Science.gov (United States)

    Chen, B.; Chen, J. M.; Higuchi, K.; Chan, D.; Shashkov, A.

    2002-05-01

    Atmospheric CO2 concentration measurements have been made by scientists of Meteorological Service of Canada on a 40 m tower for the last 10 years at 15 minute intervals over a mostly intact boreal forest near Fraserdale (50N, 81W), Ontario, Canada. The long time records of CO2 as well as basic meteorological variables provide a unique opportunity to investigate any potential changes in the ecosystem in terms of carbon balance. A model is needed to decipher the carbon cycle signals from the diurnal and seasonal variation patterns in the CO2 record. For this purpose, the Boreal Ecosystem Productivity Simulator (BEPS) is expanded to include a one-dimensional CO2 vertical transfer model involving the interaction between plant canopies and the atmosphere in the surface layer and the diurnal dynamics of the mixed layer. An analytical solution of the scalar transfer equation within the surface layer is found using an assumption that the diurnal oscillation of CO2 concentration at a given height is sinusoidal, which is suitable for the investigation of the changes in diurnal variation pattern over the 10 year period. The complex interactions between the daily cycle of the atmosphere and vegetation CO2 exchange and the daily evolution of mixed layer entrainment of CO2 determines the CO2 variation pattern at a given height. The expanded BEPS can simulate within ñ2 ppm the hourly CO2 records at the 40 m measurement height. The annual totals of gross primary productivity (GPP), net primary productivity (NPP) and net ecosystem productivity (NEP), summed up from the hourly results, agree within 5% of previous estimates of BEPS at daily steps, indicating the internal consistency of the hourly model. The model is therefore ready for exploring changes in the CO2 record as affected by changes in the forest ecosystems upwind of the tower. Preliminary results indicate that the diurnal variation amplitude of CO2 has increased by 10-20% over the 10 years period, and this change can

  16. Implementation of the NEMO model for estimating the spread of leakage from chemical munitions in the Baltic Sea - the first approach

    Science.gov (United States)

    Andrzejewski, Jan

    2017-04-01

    After the Second World War, during the Potsdam Conference a decision about demilitarization of Germany was made, and as a consequence, ammunition including chemical warfare agents (CWA) was dumped into the basins of the Baltic Sea. This type of weapon was stored in metal barrels that were under strong influence of electrochemical oxidation, also known as corrosion. Several tens years later, scientists were wondering what consequences for marine ecosystem could a leakage from this weapon bring. Although over 70 years passed since the Second World War, the influence of potential leakage of the CWA has not been properly estimated. Thus, the main goal of this work is to estimate dangerous area caused by potential leakage using the NEMO (Nucleus for European Modelling of the Ocean) ocean model. The NEMO ocean model is developed by the European Consortium including research institutes from France, England and Italy. The first step of this work is to implement the model for the area of the Baltic Sea. It requires generation of horizontal and vertical grid, bathymetry, atmospheric forces and lateral boundary conditions. Implemented model will have to be checked - it means it will have to pass a validation process. The Baltic Sea is one of the best measured sea in the World - as a consequence a lot of data are freely available for researchers. After validation and tuning up the model, implementation of passive tracer is planned. Passive tracer is the prognostic variable that could represent concentration of potential leakage and does not have influence on the density of the model. Based on distribution of the passive tracer, dangerous areas in the locations of dumpsites will be assessed. The research work was funded by the European Union (European Regional Development Fund) under the Interreg Baltic Sea Region Programme 2014-2020, project #R013 DAIMON (Decision Aid for Marine Munitions).

  17. Acoustic emission monitoring of medieval towers considered as sensitive earthquake receptors

    Directory of Open Access Journals (Sweden)

    A. Carpinteri

    2007-01-01

    Full Text Available Many ancient masonry towers are present in Italian territory. In some cases these structures are at risk on account of the intensity of the stresses they are subjected to due to the high level of regional seismicity. In order to preserve this inestimable cultural heritage, a sound safety assessment should take into account the evolution of damage phenomena. In this connection, acoustic emission (AE monitoring can be highly effective. This study concerns the structural stability of three medieval towers rising in the centre of Alba, a characteristic town in Piedmont (Italy. During the monitoring period a correlation between peaks of AE activity in the masonry of these towers and regional seismicity was found. Earthquakes always affect structural stability. Besides that, the towers behaved as sensitive earthquake receptors. Here a method to correlate bursts of AE activity in a masonry building and regional seismicity is proposed. In particular, this method permits to identify the premonitory signals that precede a catastrophic event on a structure, since, in most cases, these warning signs can be captured well in advance.

  18. Influence of stainless steel Internals on Corrosion of tower wall materials

    Science.gov (United States)

    Chen, Bing; Ren, Ke

    2017-12-01

    In view of the galvanic corrosion of the tower wall material in the tower of a refinery atmospheric vacuum distillation unit, the electrochemical behavior of Q345R steel, stainless steel (201, 304 cold-rolled plate, 304 hot rolled plate and 316L) in 3.5%NaCl solution was studied by electrochemical method. The results show that the corrosion potential of Q345R is much lower than that of stainless steel, and the corrosion rate of Q345R is higher than that of stainless steel. As the anode is etched as the anode corrosion, the anode polarizability of stainless steel shows strong polarization ability, which is anodic polarization control, and Q345R is anode Active polarization control; Q345R / 201 galvanic pair may be the most serious corrosion, and Q345R/316L galvanic couple may be relatively slight. Therefore, in the actual production of tower equipment, material design or tower to upgrade the replacement, it are recommended to use the preferred anode and cathode potential difference with the use of materials.

  19. Comparative assessment of anti-sway control strategy for tower crane system

    Science.gov (United States)

    Samin, Reza Ezuan; Mohamed, Zaharuddin

    2017-09-01

    Tower crane is also known as rotary crane and widely used in constructions due to limited human capability to carry the various types of load at the construction site. In general crane is used for the purpose of loading and unloading heavy material from one place to another. However, in order to transfer the material in minimum time from one location to another, swaying of the payload will occur. Hence, this research presents the investigation of tower crane system which mainly focusing on the swaying angle of the payload by implementing conventional and intelligent controllers. Its mathematical modeling is developed using the Newton's Second Law and simulation is done within the MATLAB/Simulink environment. Simulation results are presented in cart trajectory capability and payload sway angle reduction. A comparative assessment between conventional controller and intelligent controller for the tower crane system are presented and discussed. Furthermore, the effect of various rope length and payload mass of the tower crane system to the performance of trajectory capability and sway angle reduction are also presented and discussed.

  20. Dry cooling tower operating experience in the LOFT reactor

    International Nuclear Information System (INIS)

    Hunter, J.A.

    1980-01-01

    A dry cooling tower has been uniquely utilized to dissipate heat generated in a small experimental pressurized water nuclear reactor. Operational experience revealed that dry cooling towers can be intermittently operated with minimal wind susceptibility and water hammer occurrences by cooling potential steam sources after a reactor scram, by isolating idle tubes from the external atmosphere, and by operating at relatively high pressures. Operating experience has also revealed that tube freezing can be minimized by incorporating the proper heating and heat loss prevention features

  1. Cooling tower drift: experiment design for comprehensive case study

    International Nuclear Information System (INIS)

    Laulainen, N.S.

    1978-01-01

    A drift experiment program to develop a data base which can be used for validation of drift deposition models has been formulated. The first field effort is designed for a suitable mechanical-draft cooling tower to be selected after site visits have been conducted. The discussion here demonstrates the importance of characterizing the droplet size spectrum emitted from the tower and to accurately account for droplet evaporation, because the downwind droplet deposition patterns and near-surface airborne concentrations are extremely sensitive to these parameters

  2. Legionnaires' Disease Outbreaks and Cooling Towers, New York City, New York, USA.

    Science.gov (United States)

    Fitzhenry, Robert; Weiss, Don; Cimini, Dan; Balter, Sharon; Boyd, Christopher; Alleyne, Lisa; Stewart, Renee; McIntosh, Natasha; Econome, Andrea; Lin, Ying; Rubinstein, Inessa; Passaretti, Teresa; Kidney, Anna; Lapierre, Pascal; Kass, Daniel; Varma, Jay K

    2017-11-01

    The incidence of Legionnaires' disease in the United States has been increasing since 2000. Outbreaks and clusters are associated with decorative, recreational, domestic, and industrial water systems, with the largest outbreaks being caused by cooling towers. Since 2006, 6 community-associated Legionnaires' disease outbreaks have occurred in New York City, resulting in 213 cases and 18 deaths. Three outbreaks occurred in 2015, including the largest on record (138 cases). Three outbreaks were linked to cooling towers by molecular comparison of human and environmental Legionella isolates, and the sources for the other 3 outbreaks were undetermined. The evolution of investigation methods and lessons learned from these outbreaks prompted enactment of a new comprehensive law governing the operation and maintenance of New York City cooling towers. Ongoing surveillance and program evaluation will determine if enforcement of the new cooling tower law reduces Legionnaires' disease incidence in New York City.

  3. An experimental study on natural draft-dry cooling tower as part of the passive system for the residual decay heat removal

    International Nuclear Information System (INIS)

    Caruso, G.; Fatone, M.; Naviglio, A.

    2007-01-01

    An experimental apparatus has been built in order to perform sensitivity analysis on the performance of a natural draft-dry cooling tower. This component plays an important role in the passive system for the residual heat decay removal foreseen in the MARS reactor and in the GCFR of the Generation IV reactors. The sensitivity analysis has investigated: 1) the heat exchanger arrangement; two different arrangements have been considered: a horizontal arrangement, in which a system of electrical heaters are placed at the inlet cross section of the tower, and a vertical arrangement, with the heaters distributed vertically around the circumference of the tower. 2) The shape of the cooling tower; by varying the angle of the shell inclination it is possible to obtain a different shape for the tower itself. An upper and a lower angle inclination were modified and by a calculation procedure eleven different configuration were selected. 3) The effect of cross wind on the tower performance. An equation-based procedure to design the dry-cooling tower is presented. In order to evaluate the influence of the shape and the heat exchanger arrangement on the performance of the cooling tower, a geometrical factor (FG) and a thermal factor (FT) are introduced. By analyzing the experimental results, engineering design relations are obtained to model the cooling tower performance. The comparison between the experimental heat transfer coefficient and the heat transfer coefficient obtained by the mathematical procedure shows that there is a good agreement. The obtained results show that it is possible to evaluate the shape and the heat exchanger arrangement to optimize the performance of the cooling tower either in wind-less condition either in presence of cross wind. (authors)

  4. Structural inspection and wind analysis of redwood cooling towers at the Portsmouth Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    Chung, T.; Solack, T.; Hortel, J.

    1991-01-01

    As part of the plant upgrade program, structural analyses and field inspections were performed on four redwood cooling towers at the DOE Portsmouth gaseous diffusion plant located in Piketon, Ohio. The cooling towers are categorized as important hazard facilities. The loadings are derived from UCRL-15910 according to the pertinent hazard category. In addition to the seismic and wind loadings, the wood cooling towers are constantly subject to adverse environmental effects such as elevated temperature, chemical attack, icing and snow load, and motor vibrations. A thorough structural evaluation for all load combinations was performed for each of the cooling towers based on the structural code requirements of the Cooling Tower Institute and National Forest Products Association. Most stress criteria are unique for the redwood material. This evaluation was performed using finite element techniques on the global structural integrity and supplemented by hand calculations on the individual connection joints. Overloaded wood structural members and joints are identified by the analysis. The rectangular tower structure sits on a concrete basin that span across 60 ft by 200 ft. A major part of the cooling towers upgrading program involved field inspections of the individual cells of each tower. The primary purpose of these inspections was to identify any existing structural damage or deficiencies such as failed members, degraded wood, and deficiencies resulting from poor construction practice. Inspection of 40 cells identified some generic deficiencies that mostly are consistent with the analytical finding. Based on the analysis, some effective but inexpensive upgrading techniques were developed and recommended to bring the cooling towers into compliance with current DOE requirements

  5. Development of a mechanistically based computer simulation of nitrogen oxide absorption in packed towers

    International Nuclear Information System (INIS)

    Counce, R.M.

    1981-01-01

    A computer simulation for nitrogen oxide (NO/sub x/) scrubbing in packed towers was developed for use in process design and process control. This simulation implements a mechanistically based mathematical model, which was formulated from (1) an exhaustive literature review; (2) previous NO/sub x/ scrubbing experience with sieve-plate towers; and (3) comparisons of sequential sets of experiments. Nitrogen oxide scrubbing is characterized by simultaneous absorption and desorption phenomena: the model development is based on experiments designed to feature these two phenomena. The model was then successfully tested in experiments designed to put it in jeopardy

  6. Landscape-level terrestrial methane flux observed from a very tall tower

    Science.gov (United States)

    Desai, Ankur R.; Xu, Ke; Tian, Hanqin; Weishampel, Peter; Thom, Jonthan; Baumann, Daniel D.; Andrews, Arlyn E.; Cook, Bruce D.; King, Jennifer Y.; Kolka, Randall

    2015-01-01

    Simulating the magnitude and variability of terrestrial methane sources and sinks poses a challenge to ecosystem models because the biophysical and biogeochemical processes that lead to methane emissions from terrestrial and freshwater ecosystems are, by their nature, episodic and spatially disjunct. As a consequence, model predictions of regional methane emissions based on field campaigns from short eddy covariance towers or static chambers have large uncertainties, because measurements focused on a particular known source of methane emission will be biased compared to regional estimates with regards to magnitude, spatial scale, or frequency of these emissions. Given the relatively large importance of predicting future terrestrial methane fluxes for constraining future atmospheric methane growth rates, a clear need exists to reduce spatiotemporal uncertainties. In 2010, an Ameriflux tower (US-PFa) near Park Falls, WI, USA, was instrumented with closed-path methane flux measurements at 122 m above ground in a mixed wetland–upland landscape representative of the Great Lakes region. Two years of flux observations revealed an average annual methane (CH4) efflux of 785 ± 75 mg CCH4 m−2 yr−1, compared to a mean CO2 sink of −80 g CCO2 m−2 yr−1, a ratio of 1% in magnitude on a mole basis. Interannual variability in methane flux was 30% of the mean flux and driven by suppression of methane emissions during dry conditions in late summer 2012. Though relatively small, the magnitude of the methane source from the very tall tower measurements was mostly within the range previously measured using static chambers at nearby wetlands, but larger than a simple scaling of those fluxes to the tower footprint. Seasonal patterns in methane fluxes were similar to those simulated in the Dynamic Land Ecosystem Model (DLEM), but magnitude depends on model parameterization and input data, especially regarding wetland extent. The model was unable to simulate short

  7. Continuous measurements of methane from a tower network over Siberia

    International Nuclear Information System (INIS)

    Sasakawa, M.; Machida, T.; Saeki, T.; Koyama, Y.; Maksyutov, S.; Shimoyama, K.; Tsuda, N.; Suto, H.; Arshinov, M.; Davydov, D.; Fofonov, A.; Krasnov, O.

    2010-01-01

    We have been conducting continuous measurements of Methane (CH 4 ) concentration from an expanding network of towers (JR-STATION: Japan-Russia Siberian Tall Tower Inland Observation Network) located in taiga, steppe and wetland biomes of Siberia since 2004. High daytime means (>2000 ppb) observed simultaneously at several towers during winter, together with in situ weather data and NCEP/NCAR reanalysis data, indicate that high pressure systems caused CH 4 accumulation at subcontinental scale due to the widespread formation of an inversion layer. Daytime means sometimes exceeded 2000 ppb, particularly in the summer of 2007 when temperature and precipitation rates were anomalously high over West Siberia, which implies that CH 4 emission from wetlands were exceptionally high in 2007. Many hot spots detected by MODIS in the summer of 2007 illustrate that the contribution of biomass burning also cannot be neglected. Daytime mean CH 4 concentrations from the Siberian tower sites were generally higher than CH 4 values reported at NOAA coastal sites in the same latitudinal zone, and the difference in concentrations between two sets of sites was reproduced with a coupled Eulerian-Lagrangian transport model. Simulations of emissions from different CH 4 sources suggested that the major contributor to variation switched from wetlands during summer to fossil fuel during winter.

  8. Geologic Map of the Tower Peak Quadrangle, Central Sierra Nevada, California

    Science.gov (United States)

    Wahrhaftig, Clyde

    2000-01-01

    Introduction The Tower Peak quadrangle, which includes northernmost Yosemite National Park, is located astride the glaciated crest of the central Sierra Nevada and covers an exceptionally well-exposed part of the Sierra Nevada batholith. Granitic plutonic rocks of the batholith dominate the geology of the Tower Peak quadrangle, and at least 18 separate pre-Tertiary intrusive events have been identified. Pre-Cretaceous metamorphic rocks crop out in the quadrangle in isolated roof pendants and septa. Tertiary volcanic rocks cover granitic rocks in the northern part of the quadrangle, but are not considered in this brief summary. Potassium-argon (K-Ar) age determinations for plutonic rocks in the quadrangle range from 83 to 96 million years (Ma), including one of 86 Ma for the granodiorite of Lake Harriet (Robinson and Kistler, 1986). However, a rubidium-strontium whole-rock isochron age of 129 Ma has been obtained for the Lake Harriet pluton (Robinson and Kistler, 1986), which field evidence indicates is the oldest plutonic body within the quadrangle. This suggests that some of the K-Ar ages record an episode of resetting during later thermal events and are too young. The evidence indicates that all the plutonic rocks are of Cretaceous age, with the youngest being the Cathedral Peak Granodiorite at about 83 Ma. The pre-Tertiary rocks of the Tower Peak quadrangle fall into two groups: (1) an L-shaped area of older plutonic and metamorphic rocks, 3 to 10 km wide, that extends diagonally both northeast and southeast from near the center of the quadrangle; and (2) a younger group of large, probably composite intrusions that cover large areas in adjacent quadrangles and extend into the Tower Peak quadrangle from the east, north, and southwest.

  9. The influence and analysis of natural crosswind on cooling characteristics of the high level water collecting natural draft wet cooling tower

    Science.gov (United States)

    Ma, Libin; Ren, Jianxing

    2018-01-01

    Large capacity and super large capacity thermal power is becoming the main force of energy and power industry in our country. The performance of cooling tower is related to the water temperature of circulating water, which has an important influence on the efficiency of power plant. The natural draft counter flow wet cooling tower is the most widely used cooling tower type at present, and the high cooling tower is a new cooling tower based on the natural ventilation counter flow wet cooling tower. In this paper, for high cooling tower, the application background of high cooling tower is briefly explained, and then the structure principle of conventional cooling tower and high cooling tower are introduced, and the difference between them is simply compared. Then, the influence of crosswind on cooling performance of high cooling tower under different wind speeds is introduced in detail. Through analysis and research, wind speed, wind cooling had little impact on the performance of high cooling tower; wind velocity, wind will destroy the tower inside and outside air flow, reducing the cooling performance of high cooling tower; Wind speed, high cooling performance of cooling tower has increased, but still lower than the wind speed.

  10. Desalination using spray tower and vapour compression refrigeration system

    International Nuclear Information System (INIS)

    Sathish Kumar, S.; Mani, A.

    2006-01-01

    A desalination system using a spray tower and Vapour Compression Refrigeration (VCR) system is proposed for obtaining fresh water from brackish water. In the spray tower, simultaneous heat and mass transfer take place between the brackish water and air, which results in the evaporation of the brackish water and humidification of the air. Fresh water is obtained from the humidified air by condensing the water vapour using a VCR system. Parametric studies were carried out to study the effect of various operational parameters on the fresh water production rate. (author)

  11. 78 FR 11146 - Utility Scale Wind Towers From the People's Republic of China: Antidumping Duty Order

    Science.gov (United States)

    2013-02-15

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-981] Utility Scale Wind Towers...''), the Department is issuing an antidumping duty order on utility scale wind towers (``wind towers...) 482-3936, or (202) 482-4852, respectively. SUPPLEMENTARY INFORMATION: Background In accordance with...

  12. Influence of acidification of circulating water on differential distribution of dispersed phase

    Directory of Open Access Journals (Sweden)

    Oleksandr B. Gulyaenko

    2015-06-01

    Full Text Available The paper analyzes the connection between processing technologies of circulating water cooling tower and coagulation-aggregation properties of colloidal particles of the dispersed phase. In circulating water cooling tower when clarifying additional water the reduction of HCO3- and CO32- concentrations happens with corresponding pH increase. Absorption of atmospheric carbon dioxide by cooling tower circulating water offsets this increase. The estimation of the probability of adhesion to the surface of the dispersed phase, distributed in the volume of circulation water, and the heat exchange surface of the condenser for different degrees of evaporation of the coolant is made. The distribution of cooling water micro-disperse particles which are adsorbed on the heat exchange surfaces of the condenser (deposit formation and on the surface of larger particles (particle aggregation reflects the efficiency of applied water treatment technology. It is shown that acidification of additional water facilitates solution of most fine fractions and increases hardness of treated water.

  13. Quasi-integrable non-linear Schrödinger models, infinite towers of exactly conserved charges and bright solitons

    Science.gov (United States)

    Blas, H.; do Bonfim, A. C. R.; Vilela, A. M.

    2017-05-01

    Deformations of the focusing non-linear Schrödinger model (NLS) are considered in the context of the quasi-integrability concept. We strengthen the results of JHEP 09 (2012) 103 10.1007/JHEP06(2015)177" TargetType="URL"/> for bright soliton collisions. We addressed the focusing NLS as a complement to the one in JHEP 03 (2016) 005 10.1007/JHEP06(2015)177" TargetType="URL"/> , in which the modified defocusing NLS models with dark solitons were shown to exhibit an infinite tower of exactly conserved charges. We show, by means of analytical and numerical methods, that for certain two-bright-soliton solutions, in which the modulus and phase of the complex modified NLS field exhibit even parities under a space-reflection symmetry, the first four and the sequence of even order charges are exactly conserved during the scattering process of the solitons. We perform extensive numerical simulations and consider the bright solitons with deformed potential V=2η /2+\\upepsilon{({|ψ |}^2)}^{2+\\upepsilon},\\upepsilon \\in \\mathbb{R},η <0 . However, for two-soliton field components without definite parity we also show numerically the vanishing of the first non-trivial anomaly and the exact conservation of the relevant charge. So, the parity symmetry seems to be a sufficient but not a necessary condition for the existence of the infinite tower of conserved charges. The model supports elastic scattering of solitons for a wide range of values of the amplitudes and velocities and the set { η, ɛ}. Since the NLS equation is ubiquitous, our results may find potential applications in several areas of non-linear science.

  14. Modified corrosion protection coatings for Concrete tower of Transmission line

    Science.gov (United States)

    Guo, Kai; Jing, Xiangyang; Wang, Hongli; Yue, Zengwu; Wu, Yaping; Mi, Xuchun; Li, Xingeng; Chen, Suhong; Fan, Zhibin

    2017-12-01

    By adding nano SiO2 particles, an enhanced K-PRTV anti-pollution flashover coating had been prepared. Optical profile meter (GT-K), atomic force microscopy (AFM) and infrared spectrometer (FT-IR) characterization were carried out on the coating surface analysis. With the use of modified epoxy resin as the base material, the supplemented by phosphate as a corrosion stabilizer, to achieve a corrosion of steel and galvanized steel with rust coating. Paint with excellent adhesion, more than 10MPa (1), resistant to neutral salt spray 1000h does not appear rust point. At the same time coating a large amount of ultra-fine zinc powder can be added for the tower galvanized layer zinc repair function, while the paint in the zinc powder for the tower to provide sacrificial anode protection, to achieve self-repair function of the coating. Compared to the market with a significant reduction in the cost of rust paint, enhance the anti-corrosion properties.

  15. Hydroaerothermal investigations conducted in the USSR to justify the construction of large cooling towers

    International Nuclear Information System (INIS)

    Goncharov, V.V.

    1989-01-01

    The multi-purpose task of improving water cooling systems of thermal and nuclear power plants is aimed at the development of efficient designs of cooling towers and other types of industrial coolers which call for comprehensive scientific justification. Cooling towers of 60-70 thou m 3 /h capacity with a chimney height of 130 m and those of 80-100 thou m 3 /h capacity with a chimney height of 150 m were developed. For circulating water systems of large power plants the design of a counterflow chimney cooling tower of 180 thou m 3 /h capacity has been recently developed. At present the work is being conducted on developing a new three-cell cooling tower featuring high reliability, operational flexibility and cost-effectiveness of the design. This cooling tower, besides having higher operating reliability than the conventional one of circular shape, can ensure the commissioning, current repairs and overhauls of water cooling arrangements in a cell-wise sequence, i.e. without shutting down the power generating units. Laboratory and field investigations of the spray-type cooling towers having no packing (fill), studies on heat and mass exchanges processes, aerodynamics of droplet flows and new designs of sprayers made it possible to come to a conclusion that their cooling capacity can be substantially increased and brought up to the level of the cooling towers with film packings. The pilot cooling towers were designed according to the counterflow, crossflow and cross-counterflow schemes. The basic investigation method remains to be the experimental one. On the test rigs and aerodynamic models the heat and mass transfer and aerodynamic resistance coefficients are determined. These studies and subsequent calculations are based on the heat balance equation

  16. INVESTIGATION OF THE PERFORMANCE OF AN ATMOSPHERIC COOLING TOWER USING FRESH AND SALTED WATER

    Directory of Open Access Journals (Sweden)

    A Haddad

    2012-01-01

    Full Text Available Cooling towers are extensively used to evacuate large quantities of heat at modest temperatures through a change of phase of the flowing cooling fluid. Based on this classical principle, the present study investigates the influence of salty water on the heat exchange produced. For that purpose, experiments are carried out using fresh and salty water. Furthermore, a comparison with the results produced through an approach involving the solution of energy equation involving the flow of air on an evaporating film of fluid. The detailed results show a preponderance of fresh water over the salty.

  17. BOREAS TF-3 NSA-OBS Tower Flux, Meteorological, and Soil Temperature Data

    Science.gov (United States)

    Wofsy, Steven; Sutton, Doug; Goulden, Mike; Hall, Forrest G. (Editor); Huemmrich, Karl (Editor)

    2000-01-01

    The BOReal Ecosystem-Atmosphere Study Tower Flux (BOREAS TF-3) team collected tower flux, surface meteorological, and soil temperature data at the BOREAS Northern Study Area-Old Black Spruce (NSA-OBS) site continuously from the March 1994 through October 1996. The data are available in tabular ASCII files.

  18. Emission of a natural-draught wet cooling tower and flow conditions at the brim of the cooling tower

    International Nuclear Information System (INIS)

    Baer, E.; Billet, W.; Dittrich, H.; Ernst, G.; Roller, W.; Wurz, D.

    1975-01-01

    Between July 1973 and September 1974, measurements were carried out around a natural-draught wet cooling tower during different weather conditions. The results of these measurements are to serve as basic material for the calculation of plume diffusion. (orig./TK) [de

  19. Acoustic results of the Boeing model 360 whirl tower test

    Science.gov (United States)

    Watts, Michael E.; Jordan, David

    1990-09-01

    An evaluation is presented for whirl tower test results of the Model 360 helicopter's advanced, high-performance four-bladed composite rotor system intended to facilitate over-200-knot flight. During these performance measurements, acoustic data were acquired by seven microphones. A comparison of whirl-tower tests with theory indicate that theoretical prediction accuracies vary with both microphone position and the inclusion of ground reflection. Prediction errors varied from 0 to 40 percent of the measured signal-to-peak amplitude.

  20. Vertical Deformation Monitoring of the Suspension Bridge Tower Using GNSS: A Case Study of the Forth Road Bridge in the UK

    Directory of Open Access Journals (Sweden)

    Qusen Chen

    2018-02-01

    Full Text Available The vertical deformation monitoring of a suspension bridge tower is of paramount importance to maintain the operational safety since nearly all forces are eventually transferred as the vertical stress on the tower. This paper analyses the components affecting the vertical deformation and attempts to reveal its deformation mechanism. Firstly, we designed a strategy for high-precision GNSS data processing aiming at facilitating deformation extraction and analysis. Then, 33 months of vertical deformation time series of the southern tower of the Forth Road Bridge (FRB in the UK were processed, and the accurate subsidence and the parameters of seasonal signals were estimated based on a classic function model that has been widely studied to analyse GNSS coordinate time series. We found that the subsidence rate is about 4.7 mm/year, with 0.1 mm uncertainty. Meanwhile, a 15-month meteorological dataset was utilised with a thermal expansion model (TEM to explain the effects of seasonal signals on tower deformation. The amplitude of the annual signals correlated quite well that obtained by the TEM, with the consistency reaching 98.9%, demonstrating that the thermal effect contributes significantly to the annual signals. The amplitude of daily signals displays poor consistency with the ambient temperature data. However, the phase variation tendencies between the daily signals of the vertical deformation and the ambient temperature are highly consistent after February 2016. Finally, the potential contribution of the North Atlantic Drift (NAD to the characteristics of annual and daily signals is discussed because of the special geographical location of the FRB. Meanwhile, this paper emphasizes the importance of collecting more detailed meteorological and other loading data for the investigation of the vertical deformation mechanism of the bridge towers over time with the support of GNSS.