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Sample records for cs model coil

  1. CS model coil experimental log book

    International Nuclear Information System (INIS)

    Nishijima, Gen; Sugimoto, Makoto; Nunoya, Yoshihiko; Wakabayashi, Hiroshi; Tsuji, Hiroshi

    2001-02-01

    Charging test of the ITER CS Model Coil which is the world's largest superconducting pulse coil and the CS Insert Coil had started at April 11, 2000 and had completed at August 18, 2000. In the campaign, total shot numbers were 356 and the size of the data file in the DAS (Data Acquisition System) was over 20 GB. This report is a database that consists of the log list and the log sheets of every shot. One can access the database, make a search, and browse results via Internet (http://1ogwww.naka.jaeri.go.jp). The database will be useful to quick search to choose necessary shots. (author)

  2. CS model coil experimental log book

    Energy Technology Data Exchange (ETDEWEB)

    Nishijima, Gen; Sugimoto, Makoto; Nunoya, Yoshihiko; Wakabayashi, Hiroshi; Tsuji, Hiroshi [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    2001-02-01

    Charging test of the ITER CS Model Coil which is the world's largest superconducting pulse coil and the CS Insert Coil had started at April 11, 2000 and had completed at August 18, 2000. In the campaign, total shot numbers were 356 and the size of the data file in the DAS (Data Acquisition System) was over 20 GB. This report is a database that consists of the log list and the log sheets of every shot. One can access the database, make a search, and browse results via Internet (http://1ogwww.naka.jaeri.go.jp). The database will be useful to quick search to choose necessary shots. (author)

  3. Performance verification tests of JT-60SA CS model coil

    Energy Technology Data Exchange (ETDEWEB)

    Obana, Tetsuhiro, E-mail: obana.tetsuhiro@LHD.nifs.ac.jp [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Murakami, Haruyuki [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan); Takahata, Kazuya; Hamaguchi, Shinji; Chikaraishi, Hirotaka; Mito, Toshiyuki; Imagawa, Shinsaku [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Kizu, Kaname; Natsume, Kyohei; Yoshida, Kiyoshi [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan)

    2015-11-15

    Highlights: • The performance of the JT-60SA CS model coil was verified. • The CS model coil comprised a quad-pancake wound with a Nb{sub 3}Sn CIC conductor. • The CS model coil met the design requirements. - Abstract: As a final check of the coil manufacturing method of the JT-60 Super Advanced (JT-60SA) central solenoid (CS), we verified the performance of a CS model coil. The model coil comprised a quad-pancake wound with a Nb{sub 3}Sn cable-in-conduit conductor. Measurements of the critical current, joint resistance, pressure drop, and magnetic field were conducted in the verification tests. In the critical-current measurement, the critical current of the model coil coincided with the estimation derived from a strain of −0.62% for the Nb{sub 3}Sn strands. As a result, critical-current degradation caused by the coil manufacturing process was not observed. The results of the performance verification tests indicate that the model coil met the design requirements. Consequently, the manufacturing process of the JT-60SA CS was established.

  4. Magnetic field measurements of JT-60SA CS model coil

    Energy Technology Data Exchange (ETDEWEB)

    Obana, Tetsuhiro, E-mail: obana.tetsuhiro@LHD.nifs.ac.jp [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Takahata, Kazuya; Hamaguchi, Shinji; Chikaraishi, Hirotaka; Mito, Toshiyuki; Imagawa, Shinsaku [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Kizu, Kaname; Murakami, Haruyuki; Natsume, Kyohei; Yoshida, Kiyoshi [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan)

    2015-01-15

    Highlights: • Magnetic fields of the JT-60SA CS model coil were measured. • While the coil current was held constant at 20 kA, magnetic fields varied slightly with several different long time constants. • We investigated coils consisting of CIC conductors and having long time constants. - Abstract: In a cold test of the JT-60SA CS model coil, which has a quad-pancake configuration consisting of a Nb{sub 3}Sn cable-in-conduit (CIC) conductor, magnetic fields were measured using Hall sensors. For a holding coil current of 20 kA, measured magnetic fields varied slightly with long time constants in the range 17–571 s, which was much longer than the time constant derived from a measurement using a short straight sample. To validate the measurements, the magnetic fields of the model coil were calculated using a computational model representing the positions of Nb{sub 3}Sn strands inside the CIC conductor. The calculated results were in good agreement with the measurements. Consequently, the validity of the magnetic field measurements was confirmed. Next, we investigated other coils consisting of CIC conductors and having long time constants. The only commonality among the coils was the use of CIC conductors. At present, there is no obvious way to prevent generation of such magnetic-field variations with long time constants.

  5. TF insert experiment log book. 2nd Experiment of CS model coil

    International Nuclear Information System (INIS)

    Sugimoto, Makoto; Isono, Takaaki; Matsui, Kunihiro

    2001-12-01

    The cool down of CS model coil and TF insert was started on August 20, 2001. It took almost one month and immediately started coil charge since September 17, 2001. The charge test of TF insert and CS model coil was completed on October 19, 2001. In this campaign, total shot numbers were 88 and the size of the data file in the DAS (Data Acquisition System) was about 4 GB. This report is a database that consists of the log list and the log sheets of every shot. This is an experiment logbook for 2nd experiment of CS model coil and TF insert for charge test. (author)

  6. Upgrade of DC power supply system in ITER CS model coil test facility

    International Nuclear Information System (INIS)

    Shimono, Mitsugu; Uno, Yasuhiro; Yamazaki, Keita; Kawano, Katsumi; Isono, Takaaki

    2014-03-01

    Objective of the ITER CS Model Coil Test Facility is to evaluate a large scale superconducting conductor for fusion using the Central Solenoid (CS) Model Coil, which can generate a 13T magnetic field in the inner bore with a 1.5 m diameter. The facility is composed of a helium refrigerator / liquefier system, a DC power supply system, a vacuum system and a data acquisition system. The DC power supply system supplies currents to two superconducting coils, the CS Model Coil and an insert coil. A 50-kA DC power supply is installed for the CS Model Coil and two 30 kA DC power supplies are installed for an insert coil. In order to evaluate superconducting performance of a conductor used for ITER Toroidal Field (TF) coils whose operating current is 68 kA, the line for an insert coil is upgraded. A 10 kA DC power supply was added, DC circuit breakers were upgraded, bus bars and current measuring instrument were replaced. In accordance to the upgrade, operation manual was revised. (author)

  7. Nb3Al insert experiment log book. 3rd experiment of CS model coil

    International Nuclear Information System (INIS)

    Sugimoto, Makoto; Koizumi, Norikiyo; Isono, Takaaki

    2002-10-01

    The cool down of CS model coil and Nb 3 Al insert was started on March 4, 2002. It took almost one month and immediately started coil charge since April 3, 2002. The charge test of Nb 3 Al insert and CS model coil was completed on May 2, 2002. All of the experiments including the warm up was also completed on May 30, 2002. In this campaign, total shot numbers were 102 and the size of the data file in the DAS (Data Acquisition System) was about 5.2 GB. This report is a database that consists of the log list and the log sheets of every shot. (author)

  8. Comparison of the performances of the CS model coil and the Good Joint SULTAN sample

    International Nuclear Information System (INIS)

    Wesche, Rainer; Herzog, Robert; Bruzzone, Pierluigi

    2008-01-01

    The relevance of short sample measurements in SULTAN for the prediction of the performance of the coils of the International Thermonuclear Experimental Reactor (ITER) is assessed using the case of the Nb 3 Sn high-field central solenoid model coil (CSMC) conductor, for which both coil performance and short sample SULTAN results (Good Joint (GJ) sample) are available. A least-squares fit procedure, based on a uniform current distribution among the strands and the Durham scaling relations for the field, temperature and strain dependences of the strand J c provides a thermal strain of -0.294% and a degradation factor of approximately 60% for the GJ sample. In the calculation of the voltage along Layer 1A of the CSMC the hoop stress and the variation of the magnetic field in the conductor cross-section were taken into account. The temperature profile, used in the calculations, is based on published temperature profiles and empirical relations between helium inlet and outlet temperatures. A comparison with the GJ results indicates that short sample measurements in SULTAN provide a conservative estimate of the coil performance

  9. Manufacturing of Nb3Sn Sample Conductor for CFETR Central Solenoid Model Coil

    NARCIS (Netherlands)

    Qin, Jing Gang; Wu, Yu; Xiang, Bing Lun; Dai, Chao; Mao, Zhe Hua; Jin, Huan; Liao, Guo Jun; Liu, Fang; Xue, Tianjun; Wei, Zhou Rong; Devred, Arnaud; Nijhuis, Arend; Zhou, Chao

    2017-01-01

    China fusion engineering test reactor (CFETR) is a new tokamak device, whose magnet system includes the toroidal field, central solenoid (CS), and poloidal field coils. In order to develop the manufacturing process for the full-size CS coil, the CS model coil (CSMC) project was launched first. The

  10. NET model coil test possibilities

    International Nuclear Information System (INIS)

    Erb, J.; Gruenhagen, A.; Herz, W.; Jentzsch, K.; Komarek, P.; Lotz, E.; Malang, S.; Maurer, W.; Noether, G.; Ulbricht, A.; Vogt, A.; Zahn, G.; Horvath, I.; Kwasnitza, K.; Marinucci, C.; Pasztor, G.; Sborchia, C.; Weymuth, P.; Peters, A.; Roeterdink, A.

    1987-11-01

    A single full size coil for NET/INTOR represents an investment of the order of 40 MUC (Million Unit Costs). Before such an amount of money or even more for the 16 TF coils is invested as much risks as possible must be eliminated by a comprehensive development programme. In the course of such a programme a coil technology verification test should finally prove the feasibility of NET/INTOR TF coils. This study report is almost exclusively dealing with such a verification test by model coil testing. These coils will be built out of two Nb 3 Sn-conductors based on two concepts already under development and investigation. Two possible coil arrangements are discussed: A cluster facility, where two model coils out of the two Nb 3 TF-conductors are used, and the already tested LCT-coils producing a background field. A solenoid arrangement, where in addition to the two TF model coils another model coil out of a PF-conductor for the central PF-coils of NET/INTOR is used instead of LCT background coils. Technical advantages and disadvantages are worked out in order to compare and judge both facilities. Costs estimates and the time schedules broaden the base for a decision about the realisation of such a facility. (orig.) [de

  11. Assessment of conductor degradation in the ITER CS insert coil and implications for the ITER conductors

    Science.gov (United States)

    Mitchell, N.

    2007-01-01

    Nb3Sn cable in conduit-type conductors were expected to provide an efficient way of achieving large conductor currents at high field (up to 13 T) combined with good stability to electromagnetic disturbances due to the extensive helium contact area with the strands. Although ITER model coils successfully reached their design performance (Kato et al 2001 Fusion Eng. Des. 56/57 59-70), initial indications (Mitchell 2003 Fusion Eng. Des. 66-68 971-94) that there were unexplained performance shortfalls have been confirmed. Recent conductor tests (Pasztor et al 2004 IEEE Trans. Appl. Supercond. 14 1527-30) and modelling work (Mitchell 2005 Supercond. Sci. Technol. 18 396-404) suggest that the shortfalls are due to a combination of strand bending and filament fracture under the transverse magnetic loads. Using the new model, the extensive database from the ITER CS insert coil has been reassessed. A parametric fit based on a loss of filament area and n (the exponent of the power-law fit to the electric field) combined with a more rigorous consideration of the conductor field gradient has enabled the coil behaviour to be explained much more consistently than in earlier assessments, now fitting the Nb3Sn strain scaling laws when used with measurements of the conductor operating strain, including conditions when the insert coil current (and hence operating strain) were reversed. The coil superconducting performance also shows a fatigue-type behaviour consistent with recent measurements on conductor samples (Martovetsky et al 2005 IEEE Trans. Appl. Supercond. 15 1367-70). The ITER conductor design has already been modified compared to the CS insert, to increase the margin and provide increased resistance to the degradation, by using a steel jacket to provide thermal pre-compression to reduce tensile strain levels, reducing the void fraction from 36% to 33% and increasing the non-copper material by 25%. Test results are not yet available for the new design and performance

  12. The SMES model coil. Fabrication

    International Nuclear Information System (INIS)

    Hanai, Satoshi; Nakamoto, Kazunari; Takahashi, Nobuji

    1998-01-01

    A SMES model coil was fabricated as R and D item in the development of component technologies for a 480 MJ/20 MW SMES pilot plant. The coil consists of four double-pancake windings. The coil is the same diameter but half the number of pancakes that will be needed for a SMES pilot plant. The NbTi cable-in-conduit conductor and superconducting joints between the double pancakes are cooled by a forced flow of supercritical helium. Prior to fabrication, various characteristics of the cable-in-conduit were measured by full-sized short samples from actual conductors and by scaled short samples from scaled conductors. The critical current of the scaled short samples was in agreement with that calculated from one strand of the conductor. The impedance between arbitrary dual-oxide coated strands in the full-size conductor was measured to be smaller than that obtained from two Cr-plated strands, which showed a good degree of stability in another coil. It was estimated that oxide-coated conductors would have high stability. Through fabrication of a model coil, it was demonstrated that a large forced-flow coil for a small-scale 100 kWh SMES device could be manufactured. (author)

  13. The SMES model coil. Fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Hanai, Satoshi; Nakamoto, Kazunari; Takahashi, Nobuji [Toshiba Corp., Yokohama, Kanagawa (Japan)] [and others

    1998-07-01

    A SMES model coil was fabricated as R and D item in the development of component technologies for a 480 MJ/20 MW SMES pilot plant. The coil consists of four double-pancake windings. The coil is the same diameter but half the number of pancakes that will be needed for a SMES pilot plant. The NbTi cable-in-conduit conductor and superconducting joints between the double pancakes are cooled by a forced flow of supercritical helium. Prior to fabrication, various characteristics of the cable-in-conduit were measured by full-sized short samples from actual conductors and by scaled short samples from scaled conductors. The critical current of the scaled short samples was in agreement with that calculated from one strand of the conductor. The impedance between arbitrary dual-oxide coated strands in the full-size conductor was measured to be smaller than that obtained from two Cr-plated strands, which showed a good degree of stability in another coil. It was estimated that oxide-coated conductors would have high stability. Through fabrication of a model coil, it was demonstrated that a large forced-flow coil for a small-scale 100 kWh SMES device could be manufactured. (author)

  14. Finite element coiled cochlea model

    Science.gov (United States)

    Isailovic, Velibor; Nikolic, Milica; Milosevic, Zarko; Saveljic, Igor; Nikolic, Dalibor; Radovic, Milos; Filipović, Nenad

    2015-12-01

    Cochlea is important part of the hearing system, and thanks to special structure converts external sound waves into neural impulses which go to the brain. Shape of the cochlea is like snail, so geometry of the cochlea model is complex. The simplified cochlea coiled model was developed using finite element method inside SIFEM FP7 project. Software application is created on the way that user can prescribe set of the parameters for spiral cochlea, as well as material properties and boundary conditions to the model. Several mathematical models were tested. The acoustic wave equation for describing fluid in the cochlea chambers - scala vestibuli and scala timpani, and Newtonian dynamics for describing vibrations of the basilar membrane are used. The mechanical behavior of the coiled cochlea was analyzed and the third chamber, scala media, was not modeled because it does not have a significant impact on the mechanical vibrations of the basilar membrane. The obtained results are in good agreement with experimental measurements. Future work is needed for more realistic geometry model. Coiled model of the cochlea was created and results are compared with initial simplified coiled model of the cochlea.

  15. Design and modelling of a SMES coil

    Energy Technology Data Exchange (ETDEWEB)

    Yuan Weijia; Campbell, A M; Coombs, T A, E-mail: wy215@cam.ac.u [EPEC Superconductivity group, Engineering Department, 9 JJ Thomson Avenue, Cambridge, CB3 0FA (United Kingdom)

    2010-06-01

    The design of a Superconducting Magnetic Energy Storage (SMES) coil wound by coated conductors has been presented. Based on an existing model for coated conductor pancake coils, this paper analysed the magnetic field and current density distribution of the coil at two different operation temperatures, 77K and 22K. A comparison table of the critical currents and AC losses at these two temperatures has been presented. Several steps to improve the transport current of the coil have been suggested as well.

  16. Analysis of normal zone propagation and hot spot temperature on ITER CS insert coil

    International Nuclear Information System (INIS)

    Suwa, Tomone; Ozeki, Hidemasa; Nabara, Yoshihiro; Saito, Toru; Kawano, Katsumi; Takahashi, Yoshikazu; Isono, Takaaki; Nunoya, Yoshihiko

    2016-01-01

    The Central Solenoid (CS) insert coil consists of a 42-m-long CS conductor, of which the specifications are the same as that of the ITER CS. In order to investigate normal zone propagation and hot spot temperature, a quench test was carried out on the CS insert under End-of-Burn condition at 12.5 T and 45.1 kA of after 16,000 cycles. External heat was applied at nearly the center of the CS insert using an inductive heater, and quench was induced. A current of 45.1 kA was dumped 9.5 s (7 s) after voltage generation (Quench detection, QD). The Normal zone propagation length reached 23.4 m, and the maxim propagation velocity was 3.1 m/s just before dumping. Considering the distribution of temperature, which is calculated by GANDALF, hot spot temperature was expected to reach 227 K. As the result, it was found that the hot spot temperature exceeded the criteria of 150 K which is designed on ITER. However, heating the CS insert to 227 K did not influence conductor performance, because the current sharing temperature was maintained after the quench test. Therefore, the quench detection has a margin of approximately 9.5 s (7 s) after voltage generation (QD) in view of the conductor performance under the conditions applied in this quench test. If the hot spot temperature is kept to less than 150 K, the current should be dumped 7.5 s (5 s) before voltage generation (QD). These results are very useful for designing quench protection of the ITER CS. (author)

  17. Tesla coil theoretical model and experimental verification

    OpenAIRE

    Voitkans, Janis; Voitkans, Arnis

    2014-01-01

    Abstract – In this paper a theoretical model of a Tesla coil operation is proposed. Tesla coil is described as a long line with distributed parameters in a single-wired format, where the line voltage is measured against electrically neutral space. It is shown that equivalent two-wired scheme can be found for a single-wired scheme and already known long line theory can be applied to a Tesla coil. Formulas for calculation of voltage in a Tesla coil by coordinate and calculation of resonance fre...

  18. ITER Side Correction Coil Quench model and analysis

    Science.gov (United States)

    Nicollet, S.; Bessette, D.; Ciazynski, D.; Duchateau, J. L.; Gauthier, F.; Lacroix, B.

    2016-12-01

    Previous thermohydraulic studies performed for the ITER TF, CS and PF magnet systems have brought some important information on the detection and consequences of a quench as a function of the initial conditions (deposited energy, heated length). Even if the temperature margin of the Correction Coils is high, their behavior during a quench should also be studied since a quench is likely to be triggered by potential anomalies in joints, ground fault on the instrumentation wires, etc. A model has been developed with the SuperMagnet Code (Bagnasco et al., 2010) for a Side Correction Coil (SCC2) with four pancakes cooled in parallel, each of them represented by a Thea module (with the proper Cable In Conduit Conductor characteristics). All the other coils of the PF cooling loop are hydraulically connected in parallel (top/bottom correction coils and six Poloidal Field Coils) are modeled by Flower modules with equivalent hydraulics properties. The model and the analysis results are presented for five quench initiation cases with/without fast discharge: two quenches initiated by a heat input to the innermost turn of one pancake (case 1 and case 2) and two other quenches initiated at the innermost turns of four pancakes (case 3 and case 4). In the 5th case, the quench is initiated at the middle turn of one pancake. The impact on the cooling circuit, e.g. the exceedance of the opening pressure of the quench relief valves, is detailed in case of an undetected quench (i.e. no discharge of the magnet). Particular attention is also paid to a possible secondary quench detection system based on measured thermohydraulic signals (pressure, temperature and/or helium mass flow rate). The maximum cable temperature achieved in case of a fast current discharge (primary detection by voltage) is compared to the design hot spot criterion of 150 K, which includes the contribution of helium and jacket.

  19. Biokinetic model for 137 Cs

    International Nuclear Information System (INIS)

    Melo, Dunstana Rabelo de

    1995-01-01

    The main objective of this work was to provide a realistic biokinetic model for 137 Cs metabolism. This model was based on the retention of cesium in 57 people contaminated in the Goiania accident, ages 1 to 73 y old, complemented by data obtained in an experiment with beagle dogs, and data taken from the open literature. Cesium is distributed among all tissues and organs of the body. Its main retention site is the skeletal muscle tissue. Mathematically, cesium retention in the body may be described by a sum of three terms exponential equation. The first term represents the fraction which is rapidly eliminated in urine. This fraction is weight dependent (negative correlation). The second term represents the retention of cesium in tissues and organs of the body. For children and adolescents, the second term biological half-life is a function of the weight. For adults, it is correlated with sex. Men present a higher retention of cesium than women. The third term correspond to a retention fraction of the order of 0,1% of the initial body burden. It is characterized by a very long half-life and represents a subcellular retention of cesium in the skeletal muscle tissue. During pregnancy the transfer factor from the mother to the fetus is correlated to the amount of cesium in the blood and it is equal to 1, if the intake of cesium occurs pregnancy. (author)

  20. Automated de novo phasing and model building of coiled-coil proteins.

    Science.gov (United States)

    Rämisch, Sebastian; Lizatović, Robert; André, Ingemar

    2015-03-01

    Models generated by de novo structure prediction can be very useful starting points for molecular replacement for systems where suitable structural homologues cannot be readily identified. Protein-protein complexes and de novo-designed proteins are examples of systems that can be challenging to phase. In this study, the potential of de novo models of protein complexes for use as starting points for molecular replacement is investigated. The approach is demonstrated using homomeric coiled-coil proteins, which are excellent model systems for oligomeric systems. Despite the stereotypical fold of coiled coils, initial phase estimation can be difficult and many structures have to be solved with experimental phasing. A method was developed for automatic structure determination of homomeric coiled coils from X-ray diffraction data. In a benchmark set of 24 coiled coils, ranging from dimers to pentamers with resolutions down to 2.5 Å, 22 systems were automatically solved, 11 of which had previously been solved by experimental phasing. The generated models contained 71-103% of the residues present in the deposited structures, had the correct sequence and had free R values that deviated on average by 0.01 from those of the respective reference structures. The electron-density maps were of sufficient quality that only minor manual editing was necessary to produce final structures. The method, named CCsolve, combines methods for de novo structure prediction, initial phase estimation and automated model building into one pipeline. CCsolve is robust against errors in the initial models and can readily be modified to make use of alternative crystallographic software. The results demonstrate the feasibility of de novo phasing of protein-protein complexes, an approach that could also be employed for other small systems beyond coiled coils.

  1. Manufacture and mechanical test of a TORE SUPRA model coil

    International Nuclear Information System (INIS)

    Aymar, R.; Claudet, G.; Disdier, F.; Hamelin, J.; Libeyre, P.; Mayaux, G.; Meuris, C.; Parain, J.; Torossian, A.

    1980-09-01

    Inside the qualifying test programme, supporting the Tore Supra Design, a reduced scale model of a Bsub(T) coil was fabricated by a large industrial firm. This model coil is provided with the same features as those retained for the complete magnet. Tests of this model coil have been carried out in such a way that most of stresses which will arise in Tore Supra windings are simulated; simultaneously its cryogenic supply is fully representative of the system retained for the complete machine. Operation of the model coil has been found highly stable; under the conditions of applied field and forces a coil transition could be triggered, by an electrical heater located inside the coil, only when the temperature of the superfluid helium bath was close to Tsub(lambda). Thus, design and manufacturing techniques have been qualified satisfactorily to proceed to the next step: fabrication of the superconducting Bsub(T) coils of Tore Supra

  2. CCBuilder 2.0: Powerful and accessible coiled-coil modeling.

    Science.gov (United States)

    Wood, Christopher W; Woolfson, Derek N

    2018-01-01

    The increased availability of user-friendly and accessible computational tools for biomolecular modeling would expand the reach and application of biomolecular engineering and design. For protein modeling, one key challenge is to reduce the complexities of 3D protein folds to sets of parametric equations that nonetheless capture the salient features of these structures accurately. At present, this is possible for a subset of proteins, namely, repeat proteins. The α-helical coiled coil provides one such example, which represents ≈ 3-5% of all known protein-encoding regions of DNA. Coiled coils are bundles of α helices that can be described by a small set of structural parameters. Here we describe how this parametric description can be implemented in an easy-to-use web application, called CCBuilder 2.0, for modeling and optimizing both α-helical coiled coils and polyproline-based collagen triple helices. This has many applications from providing models to aid molecular replacement for X-ray crystallography, in silico model building and engineering of natural and designed protein assemblies, and through to the creation of completely de novo "dark matter" protein structures. CCBuilder 2.0 is available as a web-based application, the code for which is open-source and can be downloaded freely. http://coiledcoils.chm.bris.ac.uk/ccbuilder2. We have created CCBuilder 2.0, an easy to use web-based application that can model structures for a whole class of proteins, the α-helical coiled coil, which is estimated to account for 3-5% of all proteins in nature. CCBuilder 2.0 will be of use to a large number of protein scientists engaged in fundamental studies, such as protein structure determination, through to more-applied research including designing and engineering novel proteins that have potential applications in biotechnology. © 2017 The Authors Protein Science published by Wiley Periodicals, Inc. on behalf of The Protein Society.

  3. Mechanical behavior of the ATLAS B0 model coil

    CERN Document Server

    Foussat, A; Acerbi, E; Alessandria, F; Berthier, R; Broggi, F; Daël, A; Dudarev, A; Mayri, C; Miele, P; Reytier, M; Rossi, L; Sorbi, M; Sun, Z; ten Kate, H H J; Vanenkov, I; Volpini, G

    2002-01-01

    The ATLAS B0 model coil has been developed and constructed to verify the design parameters and the manufacture techniques of the Barrel Toroid coils (BT) that are under construction for the ATLAS Detector. Essential for successful operation is the mechanical behavior of the superconducting coil and its support structure. In the ATLAS magnet test facility, a magnetic mirror is used to reproduce in the model coil the electromagnetic forces of the BT coils when assembled in the final Barrel Toroid magnet system. The model coil is extensively equipped with mechanical instrumentation to monitor stresses and force levels as well as contraction during a cooling down and excitation up to nominal current. The installed set up of strain gauges, position sensors and capacitive force transducers is presented. Moreover the first mechanical results in terms of expected main stress, strain and deformation values are presented based on detailed mechanical analysis of the design. (7 refs).

  4. Finite element modeling of TFTR poloidal field coils

    International Nuclear Information System (INIS)

    Baumgartner, J.A.; O'Toole, J.A.

    1986-01-01

    The Tokamak Fusion Test Reactor (TFTR) Poloidal Field (PF) coils were originally analyzed to TFTR design conditions. The coils have been reanalyzed by PPPL and Grumman to determine operating limits under as-built conditions. Critical stress levels, based upon data obtained from the reanalysis of each PF coil, are needed for input to the TFTR simulation code algorithms. The primary objective regarding structural integrity has been to ascertain the magnitude and location of critical internal stresses in each PF coil due to various combinations of electromagnetic and thermally induced loads. For each PF coil, a global finite element model (FEM) of a coil sector is being analyzed to obtain the basic coil internal loads and displacements. Subsequent fine mesh local models of the coil lead stem and lead spur regions produce the magnitudes and locations of peak stresses. Each copper turn and its surrounding insulation are modeled using solid finite elements. The corresponding electromagnetic and thermal analyses are similarly modeled. A series of test beams were developed to determine the best combination of MSC/NASTRAN-type finite elements for use in PF coil analysis. The results of this analysis compare favorably with those obtained by the earlier analysis which was limited in scope

  5. The Normal Zone Propagation in ATLAS B00 Model Coil

    NARCIS (Netherlands)

    Boxman, E.W.; Dudarev, A.V.; ten Kate, Herman H.J.

    2002-01-01

    The B00 model coil has been successfully tested in the ATLAS Magnet Test Facility at CERN. The coil consists of two double pancakes wound with aluminum stabilized cables of the barrel- and end-cap toroids conductors for the ATLAS detector. The magnet current is applied up to 24 kA and quenches are

  6. NET model coil test possibilities in the TOSKA TWIN configuration

    International Nuclear Information System (INIS)

    Gruenhagen, A.; Heller, R.; Herz, W.; Hofmann, A.; Jentzsch, K.; Kapulla, H.; Kneifel, B.; Komarek, P.; Lehmann, W.; Maurer, W.; Ulbricht, A.; Vogt, A.; Zahn, G.

    1989-07-01

    This report continues an earlier one on the possibilities of NET model coil testing in the TOSKA Upgrade facility at KfK. The investigation of a 'Cluster Test Facility' and a 'Solenoid Test Facility' is followed by the investigation of two further test arrangements. They are called 'Twin Configurations'. One common feature of both arrangements is that the EURATOM-LCT-coil delivers a background magnetic field. This coil should be operated at a temperature of 1.8 K and an enhanced current up to 20 kA compared to the LCT test where 3.5 K and up to 16 kA were the operating conditions. In one configuration the NET model test coil is adjacent to the LCT coil (ATC = Adjacent Twin Configuration), in the other one the NET model coil is inserted into the bore of LCT coil (ITC = Inserted Twin Configuration) either upright or with a 60 0 C slope. The configurations are investigated with respect to their electromagnetic mechanical and thermo-hydraulic properties. The requirements for the necessary mechanical support structure of the LCT coil were computed. Installation and cooling of the whole system were discussed. The time schedule and the costs for the test facility modification were estimated. Advantages and disadvantages for the configurations were discussed with respect to feasibility of the test arrangement and operation. (orig.) [de

  7. Test of a model coil of TORE SUPRA

    International Nuclear Information System (INIS)

    Aymar, R.; Claudet, G.; Disdier, F.; Hamelin, J.; Libeyre, P.; Mayaux, C.; Meuris, C.; Parain, J.; Torossian, A.

    1980-10-01

    Inside the qualifying test programme, supporting the 'Tore Supra' Tokamak design, a reduced scale model of coil was fabricated by an industrial firm and fully tested. This model coil is provided with the same features as those retained for the complete magnet and is built according to the same design; in particular the Nb-Ti mixed matrix monolithic conductor is cooled by a pressurized superfluid helium bath, supplied from a model of the envisaged complete cryogenic system. Three main objectives have been assigned to this test: operation of the cryogenic system, stability of the superconductor winding under high mechanical stresses, mainly shear, and simulation of coil quench conditions. For this purpose, the model coil (outside bore 0.8 m) is located inside a 4 T magnet, an hydraulic jack applies a 1 MN force along a coil diameter. Operation of the model coil has been found highly stable, under the conditions of applied field and forces, a coil transition can be induced by an electrical heater only when the superfluid bath temperature is close to Tlambda. The 1.8 K cryogenic system provides a useful calorimetric measure of total losses induced inside the winding; its operation has been quite simple and reliable, permitting a sure extrapolation to a much larger size

  8. Tesla Coil Theoretical Model and its Experimental Verification

    OpenAIRE

    Voitkans Janis; Voitkans Arnis

    2014-01-01

    In this paper a theoretical model of Tesla coil operation is proposed. Tesla coil is described as a long line with distributed parameters in a single-wire form, where the line voltage is measured across electrically neutral space. By applying the principle of equivalence of single-wire and two-wire schemes an equivalent two-wire scheme can be found for a single-wire scheme and the already known long line theory can be applied to the Tesla coil. A new method of multiple re...

  9. Test results of the SMES model coil. Pulse performance

    International Nuclear Information System (INIS)

    Hamajima, Takataro; Shimada, Mamoru; Ono, Michitaka

    1998-01-01

    A model coil for superconducting magnetic energy storage (SMES model coil) has been developed to establish the component technologies needed for a small-scale 100 kWh SMES device. The SMES model coil was fabricated, and then performance tests were carried out in 1996. The coil was successfully charged up to around 30 kA and down to zero at the same ramp rate of magnetic field experienced in a 100 kWh SMES device. AC loss in the coil was measured by an enthalpy method as parameters of ramp rate and flat top current. The results were evaluated by an analysis and compared with short-sample test results. The measured hysteresis loss is in good agreement with that estimated from the short-sample results. It was found that the coupling loss of the coil consists of two major coupling time constants. One is a short time constant of about 200 ms, which is in agreement with the test results of a short real conductor. The other is a long time constant of about 30 s, which could not be expected from the short sample test results. (author)

  10. Tesla Coil Theoretical Model and its Experimental Verification

    Directory of Open Access Journals (Sweden)

    Voitkans Janis

    2014-12-01

    Full Text Available In this paper a theoretical model of Tesla coil operation is proposed. Tesla coil is described as a long line with distributed parameters in a single-wire form, where the line voltage is measured across electrically neutral space. By applying the principle of equivalence of single-wire and two-wire schemes an equivalent two-wire scheme can be found for a single-wire scheme and the already known long line theory can be applied to the Tesla coil. A new method of multiple reflections is developed to characterize a signal in a long line. Formulas for calculation of voltage in Tesla coil by coordinate and calculation of resonance frequencies are proposed. The theoretical calculations are verified experimentally. Resonance frequencies of Tesla coil are measured and voltage standing wave characteristics are obtained for different output capacities in the single-wire mode. Wave resistance and phase coefficient of Tesla coil is obtained. Experimental measurements show good compliance with the proposed theory. The formulas obtained in this paper are also usable for a regular two-wire long line with distributed parameters.

  11. Dynamic modelling of Cs-137 contamination in Denmark

    International Nuclear Information System (INIS)

    Oehlenschlaeger, M.

    1989-01-01

    The paper describes the structure of a dynamic food-chain transport model for Cs-137 in the Danish terrestrial environment. The model solves a set of linear, coupled differential equations in order to estimate the inventories and concentrations of Cs-137 in the soil, vegetation, animal tissue and animal product as a function of time based on the Cs-137 concentrations in the air after an accidental release. Meteorological conditions and seasonal variations in agricultural practice are included. (orig.)

  12. Modelling 137Cs uptake in plants from undisturbed soil monoliths

    International Nuclear Information System (INIS)

    Waegeneers, Nadia; Smolders, Erik; Merckx, Roel

    2005-01-01

    A model predicting 137 Cs uptake in plants was applied on data from artificially contaminated lysimeters. The lysimeter data involve three different crops (beans, ryegrass and lettuce) grown on five different soils between 3 and 5 years after contamination and where soil solution composition was monitored. The mechanistic model predicts plant uptake of 137 Cs from soil solution composition. Predicted K concentrations in the rhizosphere were up to 50-fold below that in the bulk soil solution whereas corresponding 137 Cs concentration gradients were always less pronounced. Predictions of crop 137 Cs content based on rhizosphere soil solution compositions were generally closer to observations than those based on bulk soil solution composition. The model explained 17% (beans) to 91% (lettuce) of the variation in 137 Cs activity concentrations in the plants. The model failed to predict the 137 Cs activity concentration in ryegrass where uptake of the 5-year-old 137 Cs from 3 soils was about 40-fold larger than predicted. The model generally underpredicted crop 137 Cs concentrations at soil solution K concentration below about 1.0 mM. It is concluded that 137 Cs uptake can be predicted from the soil solution composition at adequate K nutrition but that significant uncertainties remain when soil solution K is below 1 mM

  13. Modeling of Lossy Inductance in Moving-Coil Loudspeakers

    DEFF Research Database (Denmark)

    Kong, Xiao-Peng; Agerkvist, Finn T.; Zeng, Xin-Wu

    2015-01-01

    The electrical impedance of moving-coil loudspeakers is dominated by the lossy inductance in high frequency range. Using the equivalent electrical circuit method, a new model for the lossy inductance based on separate functions for the magnitude and phase of the impedance is presented. The electr......The electrical impedance of moving-coil loudspeakers is dominated by the lossy inductance in high frequency range. Using the equivalent electrical circuit method, a new model for the lossy inductance based on separate functions for the magnitude and phase of the impedance is presented...

  14. The normal zone propagation in ATLAS B00 model coil

    CERN Document Server

    Boxman, E W; ten Kate, H H J

    2002-01-01

    The B00 model coil has been successfully tested in the ATLAS Magnet Test Facility at CERN. The coil consists of two double pancakes wound with aluminum stabilized cables of the barrel- and end-cap toroids conductors for the ATLAS detector. The magnet current is applied up to 24 kA and quenches are induced by firing point heaters. The normal zone velocity is measured over a wide range of currents by using pickup coils, voltage taps and superconducting quench detectors. The signals coming from various sensors are presented and analyzed. The results extracted from the various detection methods are in good agreement. It is found that the characteristic velocities vary from 5 to 20 m/s at 15 and 24 kA respectively. In addition, the minimum quench energies at different applied magnet currents are presented. (6 refs).

  15. Synthesis, model and stability of helically coiled carbon nanotubes

    DEFF Research Database (Denmark)

    Fejes, Dora; Raffai, Manuella; Hernadi, Klara

    2013-01-01

    . Our experiments focused on the production and development of catalysts for the synthesis of helically coiled CNTs (carbon nanotubes). The catalysts were tested in the decomposition of acetylene by CCVD (Catalytic Chemical Vapor Deposition) method. The carbon deposit was imaged by TEM (Transmission......Structural model of helically coiled carbon nanotubes is proposed. It is constructed by means of topological coordinate method. Relaxation and cohesive energy calculation are performed by molecular mechanics, using second-generation bond order potential for hydrocarbons introduced by D. W. Brenner...

  16. Modelling of a Coil Steam Generator for CSP applications

    DEFF Research Database (Denmark)

    Pelagotti, Leonardo; Sørensen, Kim; Condra, Thomas Joseph

    2014-01-01

    The project investigates a new design for a CSP plant steam generation system, the Coil Steam Generator (CSG). This system allows faster start-ups and therefore higher daily energy production from the Sun. An analytical thermodynamic simulation model of the evaporator and a mechanical analysis...

  17. Completion of the ITER central solenoid model coils installation

    International Nuclear Information System (INIS)

    Tsuji, H.

    1999-01-01

    The short article details how dozens of problems, regarding the central solenoid model coils installation, were faced and successfully overcome one by one at JAERI-Naga. A black and white photograph shows K. Kwano, a staff member of the JAERI superconducting magnet laboratory, to be still inside the vacuum tank while the lid is already being brought down..

  18. Modelling of inductively coupled discharges excited by internal coils

    International Nuclear Information System (INIS)

    Lister, G.G.

    1991-01-01

    Modelling of inductively coupled discharges provides a method for computing parameters such as current, electrical conductivity and electromagnetic field strengths which are difficult to measure experimentally. The models reported in the literature to date deal with discharges which are surrounded by an induction coil where the plasma is considered as a one-turn secondary winding of a transformer. Eckert derived expressions for electromagnetic fields and impedance in discharges assuming Bessel function solutions to the wave and electron density equations, while more recently Denneman solved the non-linear problem, including the effects of a radial conductivity profile on the electromagnetic fields in a Ar-Hg discharge. Modelling of an ICD in which the coil is in the centre of the discharge presents an additional difficulty, since the coil does not provide a natural external boundary condition. In this paper, we compare numerical results from the approaches of Eckert and Denneman applied to discharges with internal coils, with a view to identifying relevant parameters applicable to interpretation of experiments. (author) 2 refs., 2 figs., 1 tab

  19. Equilibrium modeling of the TFCX poloidal field coil system

    International Nuclear Information System (INIS)

    Strickler, D.J.; Miller, J.B.; Rothe, K.E.; Peng, Y.K.M.

    1984-04-01

    The Toroidal Fusion Core Experiment (TFCX) isproposed to be an ignition device with a low safety factor (q approx. = 2.0), rf or rf-assisted startup, long inductive burn pulse (approx. 300 s), and an elongated plasma cross section (kappa = 1.6) with moderate triangularity (delta = 0.3). System trade studies have been carried out to assist in choosing an appropriate candidate for TFCX conceptual design. This report describes an important element in these system studies - the magnetohydrodynamic (MHD) equilibrium modeling of the TFCX poloidal field (PF) coil system and its impact on the choice of machine size. Reference design points for the all-super-conducting toroidal field (TF) coil (TFCX-S) and hybrid (TFCX-H) options are presented that satisfy given PF system criteria, including volt-second requirements during burn, mechanical configuration constraints, maximum field constraints at the superconducting PF coils, and plasma shape parameters. Poloidal coil current waveforms for the TFCX-S and TFCX-H reference designs consistent with the equilibrium requirements of the plasma startup, heating, and burn phases of a typical discharge scenario are calculated. Finally, a possible option for quasi-steady-state operation is discussed

  20. Detailed 3D models of the induced electric field of transcranial magnetic stimulation coils

    International Nuclear Information System (INIS)

    Salinas, F S; Lancaster, J L; Fox, P T

    2007-01-01

    Previous models neglected contributions from current elements spanning the full geometric extent of wires in transcranial magnetic stimulation (TMS) coils. A detailed account of TMS coil wiring geometry is shown to provide significant improvements in the accuracy of electric field (E-field) models. Modeling E-field dependence based on the TMS coil's wire width, height, shape and number of turns clearly improved the fit of calculated-to-measured E-fields near the coil body. Detailed E-field models were accurate up to the surface of the coil body (within 0.5% of measured) where simple models were often inadequate (up to 32% different from measured)

  1. Modelling Wireless Power Transfer Using an Array of Tesla Coils

    Science.gov (United States)

    Pierson, Casey Thomas

    Wireless power transmission, or WPT, is a well-demonstrated property in electrical science and physics. Coil-and-wave transmission (CWT) consists of two Tesla coils, one powered by a controlled voltage source v src and one connected across a generic load Z 0 , at a mid- to long range distance apart with spherical capacitors at each of their top loads. The literature on the different methods of WPT varies widely, but research of CWT is sparse, lacking especially in the area of computer simulation. Recently, a physical experiment was conducted by Marzolf et al. in [1], and yielded surprising resonant frequencies in the high frequency range. The goal of this research is to answer the question of whether these reosnant frequencies originate in unexplained field effects or in non-ideal circuit behavior, and establish a formal model to indicate at what frequencies the resonant peaks occur as a first approximation. By carefully constructing a simulation of the most geometrically simple, power efficient design in the work of Marzolf et al. using the scientific software Octave, we investigate these frequencies computationally: first, an ideal scenario that has no flux leakage or exterior losses is modelled mathematically and simulated, and then, a non-ideal scenario that accounts for losses in the coils and surroundings is modelled mathematically and simulated. Both models utilize a simple formula for spherical capacitance for the top loads. After running these simulations through detailed sampling up to 4 MHz, the ideal model could not account for the resonant peaks, while the non-ideal model indicated the resonant peaks near the exact frequency ranges that were observed. An unexpected characteristic of these results was that coupling coefficients between the coils of the transmitter and receiver played a noticeable part in the indication of resonant peaks. This demonstrates that unknown field effects are not the primary driver of resonance in the ideal or non

  2. Improved transcranial magnetic stimulation coil design with realistic head modeling

    Science.gov (United States)

    Crowther, Lawrence; Hadimani, Ravi; Jiles, David

    2013-03-01

    We are investigating Transcranial magnetic stimulation (TMS) as a noninvasive technique based on electromagnetic induction which causes stimulation of the neurons in the brain. TMS can be used as a pain-free alternative to conventional electroconvulsive therapy (ECT) which is still widely implemented for treatment of major depression. Development of improved TMS coils capable of stimulating subcortical regions could also allow TMS to replace invasive deep brain stimulation (DBS) which requires surgical implantation of electrodes in the brain. Our new designs allow new applications of the technique to be established for a variety of diagnostic and therapeutic applications of psychiatric disorders and neurological diseases. Calculation of the fields generated inside the head is vital for the use of this method for treatment. In prior work we have implemented a realistic head model, incorporating inhomogeneous tissue structures and electrical conductivities, allowing the site of neuronal activation to be accurately calculated. We will show how we utilize this model in the development of novel TMS coil designs to improve the depth of penetration and localization of stimulation produced by stimulator coils.

  3. Fault condition stress analysis of NET 16 TF coil model

    International Nuclear Information System (INIS)

    Jong, C.T.J.

    1992-04-01

    As part of the design process of the NET/ITER toroidal field coils (TFCs), the mechanical behaviour of the magnetic system under fault conditions has to be analysed in some detail. Under fault conditions, either electrical or mechanical, the magnetic loading of the coils becomes extreme and further mechanical failure of parts of the overall structure might occur (e.g. failure of the coil, gravitational support, intercoil structure). The mechanical behaviour of the magnetic system under fault conditions has been analysed with a finite element model of the complete TFC system. The analysed fault conditions consist of: a thermal fault, electrical faults and mechanical faults. The mechanical faults have been applied simultaneously with an electrical fault. This report described the work carried out to create the finite element model of 16 TFCs and contains an extensive presentation of the results, obtained with this model, of a normal operating condition analysis and 9 fault condition analyses. Chapter 2-5 contains a detailed description of the finite element model, boundary conditions and loading conditions of the analyses made. Chapters 2-4 can be skipped if the reader is only interested in results. To understand the results presented chapter 6 is recommended, which contains a detailed description of all analysed fault conditions. The dimensions and geometry of the model correspond to the status of the NET/ITER TFC design of May 1990. Compared with previous models of the complete magnetic system, the finite element model of 16 TFCs is 'detailed', and can be used for linear elastic analysis with faulted loads. (author). 8 refs.; 204 figs.; 134 tabs

  4. Mechanisms and models of 137Cs migration in soil

    International Nuclear Information System (INIS)

    Frid, A.S.

    1999-01-01

    The most wide-spread mechanisms and models of the 137 Cs isotope migration in soil are considered because of urgency of this problem conditioned by global fallout during nuclear weapon tests and contamination of territories due to accidents on nuclear objects (including the East Urals and ChNPP accident). It is shown that the 137 Cs migration models with an account of the sorption-desorption kinetics have from the practical adequacy certain advantage in comparison with other models, though they are mathematically more complex and require complex calculations [ru

  5. Finite element and analytical models for twisted and coiled actuator

    Science.gov (United States)

    Tang, Xintian; Liu, Yingxiang; Li, Kai; Chen, Weishan; Zhao, Jianguo

    2018-01-01

    Twisted and coiled actuator (TCA) is a class of recently discovered artificial muscle, which is usually made by twisting and coiling polymer fibers into spring-like structures. It has been widely studied since discovery due to its impressive output characteristics and bright prospects. However, its mathematical models describing the actuation in response to the temperature are still not fully developed. It is known that the large tensile stroke is resulted from the untwisting of the twisted fiber when heated. Thus, the recovered torque during untwisting is a key parameter in the mathematical model. This paper presents a simplified model for the recovered torque of TCA. Finite element method is used for evaluating the thermal stress of the twisted fiber. Based on the results of the finite element analyses, the constitutive equations of twisted fibers are simplified to develop an analytic model of the recovered torque. Finally, the model of the recovered torque is used to predict the deformation of TCA under varying temperatures and validated against experimental results. This work will enhance our understanding of the deformation mechanism of TCAs, which will pave the way for the closed-loop position control.

  6. Mathematical model of 137Cs dynamics in the deciduous forest

    International Nuclear Information System (INIS)

    Mamikhin, S.V.; Klyashtorin, A.L.

    1999-01-01

    A mathematical model of 137 Cs behaviour in the forest ecosystem is presented. The behaviour of this radionuclide is assumed to obey the same regularities as the behaviour of its stable chemical analogue, potassium. Radionuclide dynamics are considered in parallel with the dynamics of the phytomass. Radionuclides contained in the vegetation are pooled into two basic compartments: external and internal contamination, with separate analysis of each. The model was verified using the data obtained in the 30-km zone of the Chernobyl NPP in 1986-1994. The algorithm described was found to be the most efficient in terms of 137 Cs behaviour in the forest environments

  7. Results of the ITER toroidal field model coil project

    International Nuclear Information System (INIS)

    Salpietro, E.; Maix, R.

    2001-01-01

    In the scope of the ITER EDA one of the seven largest projects was devoted to the development, manufacture and testing of a Toroidal Field Model Coil (TFMC). The industry consortium AGAN manufactured the TFMC based on on a conceptual design developed by the ITER EDA EU Home Team. The TFMC was completed and assembled in the test facility TOSKA of the Forschungszentrum Karlsruhe in the first half of 2001. The first testing phase started in June 2001 and lasted till October 2001. The first results have shown that the main goals of the project have been achieved

  8. Modelling of subsonic COIL with an arbitrary magnetic modulation

    Science.gov (United States)

    Beránek, Jaroslav; Rohlena, Karel

    2007-05-01

    The concept of 1D subsonic COIL model with a mixing length was generalized to include the influence of a variable magnetic field on the stimulated emission cross-section. Equations describing the chemical kinetics were solved taking into account together with the gas temperature also a simplified mixing model of oxygen and iodine molecules. With the external time variable magnetic field the model is no longer stationary. A transformation in the system moving with the mixture reduces partial differential equations to ordinary equations in time with initial conditions given either by the stationary flow at the moment when the magnetic field is switched on combined with the boundary conditions at the injector. Advantage of this procedure is a possibility to consider an arbitrary temporal dependence of the imposed magnetic field and to calculate directly the response of the laser output. The method was applied to model the experimental data measured with the subsonic version of the COIL device in the Institute of Physics, Prague, where the applied magnetic field had a saw-tooth dependence. We found that various values characterizing the laser performance, such as the power density distribution over the active zone cross-section, may have a fairly complicated structure given by combined effects of the delayed reaction to the magnetic switching and the flow velocity. This is necessarily translated in a time dependent spatial inhomogeneity of output beam intensity profile.

  9. Mechanical test of the model coil wound with large conductor

    International Nuclear Information System (INIS)

    Hiue, Hisaaki; Sugimoto, Makoto; Nakajima, Hideo; Yasukawa, Yukio; Yoshida, Kiyoshi; Hasegawa, Mitsuru; Ito, Ikuo; Konno, Masayuki.

    1992-09-01

    The high rigidity and strength of the winding pack are required to realize the large superconducting magnet for the fusion reactor. This paper describes mechanical tests concerning the rigidity of the winding pack. Samples were prepared to evaluate the adhesive strength between conductors and insulators. Epoxy and Bismaleimide-Triazine resin (BT resin) were used as the conductor insulator. The stainless steel (SS) 304 bars, whose surface was treated mechanically and chemically, was applied to the modeled conductor. The model coil was would with the model conductors covered with the insulator by grand insulator. A winding model combining 3 x 3 conductors was produced for measuring shearing rigidity. The sample was loaded with pure shearing force at the LN 2 temperature. The bar winding sample, by 8 x 6 conductors, was measured the bending rigidity. These three point bending tests were carried out at room temperature. The pancake winding sample was loaded with compressive forces to measure compressive rigidity of winding. (author)

  10. Simulation Model solves exact the Enigma named Generating high Voltages and high Frequencies by Tesla Coil

    OpenAIRE

    Simo Janjanin

    2016-01-01

    Simulation model of Tesla coil has been successfully completed, and has been verified the procedure and functioning. The literature and documentation for the model were taken from the rich sources, especially the copies of Tesla patents. The oscillating system‟s electrical scheme consists of the voltage supply 220/50 Hz, Fe transformer, capacitor and belonging chosen electrical components, the air gap in the primary Tesla coil (air transformer) and spark gap in the exit of the coil. The inves...

  11. Modelling and Optimization of Four-Segment Shielding Coils of Current Transformers.

    Science.gov (United States)

    Gao, Yucheng; Zhao, Wei; Wang, Qing; Qu, Kaifeng; Li, He; Shao, Haiming; Huang, Songling

    2017-05-26

    Applying shielding coils is a practical way to protect current transformers (CTs) for large-capacity generators from the intensive magnetic interference produced by adjacent bus-bars. The aim of this study is to build a simple analytical model for the shielding coils, from which the optimization of the shielding coils can be calculated effectively. Based on an existing stray flux model, a new analytical model for the leakage flux of partial coils is presented, and finite element method-based simulations are carried out to develop empirical equations for the core-pickup factors of the models. Using the flux models, a model of the common four-segment shielding coils is derived. Furthermore, a theoretical analysis is carried out on the optimal performance of the four-segment shielding coils in a typical six-bus-bars scenario. It turns out that the "all parallel" shielding coils with a 45° starting position have the best shielding performance, whereas the "separated loop" shielding coils with a 0° starting position feature the lowest heating value. Physical experiments were performed, which verified all the models and the conclusions proposed in the paper. In addition, for shielding coils with other than the four-segment configuration, the analysis process will generally be the same.

  12. Analytical Model and Optimized Design of Power Transmitting Coil for Inductively Coupled Endoscope Robot.

    Science.gov (United States)

    Ke, Quan; Luo, Weijie; Yan, Guozheng; Yang, Kai

    2016-04-01

    A wireless power transfer system based on the weakly inductive coupling makes it possible to provide the endoscope microrobot (EMR) with infinite power. To facilitate the patients' inspection with the EMR system, the diameter of the transmitting coil is enlarged to 69 cm. Due to the large transmitting range, a high quality factor of the Litz-wire transmitting coil is a necessity to ensure the intensity of magnetic field generated efficiently. Thus, this paper builds an analytical model of the transmitting coil, and then, optimizes the parameters of the coil by enlarging the quality factor. The lumped model of the transmitting coil includes three parameters: ac resistance, self-inductance, and stray capacitance. Based on the exact two-dimension solution, the accurate analytical expression of ac resistance is derived. Several transmitting coils of different specifications are utilized to verify this analytical expression, being in good agreements with the measured results except the coils with a large number of strands. Then, the quality factor of transmitting coils can be well predicted with the available analytical expressions of self- inductance and stray capacitance. Owing to the exact estimation of quality factor, the appropriate coil turns of the transmitting coil is set to 18-40 within the restrictions of transmitting circuit and human tissue issues. To supply enough energy for the next generation of the EMR equipped with a Ø9.5×10.1 mm receiving coil, the coil turns of the transmitting coil is optimally set to 28, which can transfer a maximum power of 750 mW with the remarkable delivering efficiency of 3.55%.

  13. Mechanical-Stress Analytical Modeling for the Design of Coils in Power Applications

    Directory of Open Access Journals (Sweden)

    Bellan D.

    2014-12-01

    Full Text Available Modern electrical-power systems are often exploited for transmitting high-frequency carrier signals for communications purposes. Series-connected air-core coils represent the fundamental component allowing such applications by providing a proper filtering in the frequency domain. They must be designed, however, to withstand also the line short-circuit current. When a high-magnitude current flows through a coil, strong mechanical stresses are produced within the conductor, leading to possible damage of the coil. In this paper, an approximate analytical model is derived for the relationship between the maximum mechanical stress and the electrical/geometrical parameters of the coil. Such a model provides the guidelines for a fast and safe coil design, whereas numerical simulations are only needed for the design refinement. The presented approach can be extended to other applications such as, for example, the mechanical stress resulting from the inrush currents in the coils of power transformers.

  14. Evaluation of modelling body burden of Cs-137

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, U; Nordlinder, S

    1996-05-01

    Within the IAEA/CEC VAMP-program one working group studied the precision in dose assessment models when calculating body burden of {sup 137}Cs as a result of exposure through multiple exposure pathways. One scenario used data from southern Finland regarding contamination of various media due to the fallout from the Chernobyl accident. In this study, a time dependent multiple exposure pathway model was constructed based on compartment theory. Uncertainties in model responses due to uncertainties in input parameter values were studied. The initial predictions for body burden were good, within a factor of 2 of the observed, while the time dynamics of levels in milk and meat did not agree satisfactorily. Some results, nevertheless, showed good agreement with observations due to compensatory effects. After disclosure of additional observational data, major reasons for mispredictions were identified as lack of consideration of time dependence of fixation of {sup 137}Cs in soils, and the selection of parameter values. When correction of this was made, a close agreement between predictions and observations was obtained. This study shows that the dose contribution due to {sup 137}Cs in food products from the seminatural environment is important for long-term exposure to man. The evaluation provided a basis for improvements of crucial parts in the model. 14 refs, 18 figs, 8 tabs.

  15. Evaluation of modelling body burden of Cs-137

    International Nuclear Information System (INIS)

    Bergstroem, U.; Nordlinder, S.

    1996-05-01

    Within the IAEA/CEC VAMP-program one working group studied the precision in dose assessment models when calculating body burden of 137 Cs as a result of exposure through multiple exposure pathways. One scenario used data from southern Finland regarding contamination of various media due to the fallout from the Chernobyl accident. In this study, a time dependent multiple exposure pathway model was constructed based on compartment theory. Uncertainties in model responses due to uncertainties in input parameter values were studied. The initial predictions for body burden were good, within a factor of 2 of the observed, while the time dynamics of levels in milk and meat did not agree satisfactorily. Some results, nevertheless, showed good agreement with observations due to compensatory effects. After disclosure of additional observational data, major reasons for mispredictions were identified as lack of consideration of time dependence of fixation of 137 Cs in soils, and the selection of parameter values. When correction of this was made, a close agreement between predictions and observations was obtained. This study shows that the dose contribution due to 137 Cs in food products from the seminatural environment is important for long-term exposure to man. The evaluation provided a basis for improvements of crucial parts in the model. 14 refs, 18 figs, 8 tabs

  16. Test results of the SMES model coil. Cool-down and thermal characteristics

    International Nuclear Information System (INIS)

    Hamada, Kazuya; Kato, Takashi; Kawano, Katsumi

    1998-01-01

    A model coil of a superconducting magnetic energy storage (SMES) device, which is a forced-cooled Nb-Ti coil, has been fabricated and a performance test at cryogenic temperatures has been carried out. The SMES model coil is composed of 4 dual pancakes and its total weight is 4.5 t. The applied conductors are cable-in-conduit conductors cooled by supercritical helium (SHe) at 4.5 K and 0.7 MPa. SHe is supplied to the SMES model coil and the structure by a reciprocating bellows pump. The test facility is located at the International Thermonuclear Experimental Reactor (ITER) common test facility, was constructed for the testing of an ITER central solenoid model coil. In the experiments, cool-down was finished within 10 days under controlled temperature differences in the SMES model coil. During cool-down and 4.5 K operation, pressure drop characteristics of the conductor were measured and the friction factor estimated. The pressure drop characteristics of the SMES model coil were in good agreement with those of the previous cable-in-conduit conductor. During static operation without current, the heat load and refrigerator operation conditions were measured. The heat load of the SMES model coil is 7.5 W, which is within the expected value. (author)

  17. Detailed 3D models of the induced electric field of transcranial magnetic stimulation coils

    Energy Technology Data Exchange (ETDEWEB)

    Salinas, F S; Lancaster, J L; Fox, P T [Research Imaging Center, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229 (United States)

    2007-05-21

    Previous models neglected contributions from current elements spanning the full geometric extent of wires in transcranial magnetic stimulation (TMS) coils. A detailed account of TMS coil wiring geometry is shown to provide significant improvements in the accuracy of electric field (E-field) models. Modeling E-field dependence based on the TMS coil's wire width, height, shape and number of turns clearly improved the fit of calculated-to-measured E-fields near the coil body. Detailed E-field models were accurate up to the surface of the coil body (within 0.5% of measured) where simple models were often inadequate (up to 32% different from measured)

  18. Electrothermal model of choking-coils for the analysis of dc-dc converters

    Energy Technology Data Exchange (ETDEWEB)

    Gorecki, Krzysztof, E-mail: gorecki@am.gdynia.pl [Gdynia Maritime University, Department of Marine Electronics, Morska 83, Gdynia (Poland); Detka, Kalina [Pomeranian Higher School in Gdynia, Opata Hackiego 8-10, Gdynia (Poland)

    2012-09-01

    The paper concerns modelling the choking-coil for the needs of the electrothermal analysis of dc-dc converters. A new electrothermal model of the choking-coil is proposed. This model is dedicated for SPICE software and it takes into account nonlinearity of the dependences of the inductance on the current, selfheating and mutual thermal interactions between the core and the winding. The structure of this model is described in detail and its correctness is experimentally verified for the choking-coils with the ferrite and powder cores. Both the characteristics of the choking-coils and the buck converter with these choking-coils were considered. The satisfying agreement between the results of calculations and measurements is obtained.

  19. Electrothermal model of choking-coils for the analysis of dc–dc converters

    International Nuclear Information System (INIS)

    Górecki, Krzysztof; Detka, Kalina

    2012-01-01

    The paper concerns modelling the choking-coil for the needs of the electrothermal analysis of dc–dc converters. A new electrothermal model of the choking-coil is proposed. This model is dedicated for SPICE software and it takes into account nonlinearity of the dependences of the inductance on the current, selfheating and mutual thermal interactions between the core and the winding. The structure of this model is described in detail and its correctness is experimentally verified for the choking-coils with the ferrite and powder cores. Both the characteristics of the choking-coils and the buck converter with these choking-coils were considered. The satisfying agreement between the results of calculations and measurements is obtained.

  20. Mechanical Design of the SMC (Short Model Coil) Dipole Magnet

    International Nuclear Information System (INIS)

    Regis, F.; Fessia, P.; Bajko, M.; Rijk, G. de; Manil, P.

    2010-01-01

    The Short Model Coil (SMC) working group was set in February 2007 within the Next European Dipole (NED) program, in order to develop a short-scale model of a Nb 3 Sn dipole magnet. The SMC group comprises four laboratories: CERN/TE-MSC group (CH), CEA/IRFU (FR), RAL (UK) and LBNL (US). The SMC magnet was originally conceived to reach a peak field of about 13 T on conductor, using a 2500 A/mm 2 Powder-In-Tube (PIT) strand. The aim of this magnet device is to study the degradation of the magnetic properties of the Nb 3 Sn cable, by applying different level of pre-stress. To fully satisfy this purpose, a versatile and easy-to-assemble structure has to be realized. The design of the SMC magnet has been developed from an existing dipole magnet, the SD01, designed, built and tested at LBNL with support from CEA. In this paper we will describe the mechanical optimization of the dipole, starting from a conceptual configuration based on a former magnetic analysis. Two and three-dimensional Finite Element Method (FEM) models have been implemented in ANSYS and in CAST3M, aiming at setting the mechanical parameters of the dipole magnet structure, thus fulfilling the design constraints imposed by the materials. (authors)

  1. Mechanical Design of the SMC (Short Model Coil) Dipole Magnet

    Energy Technology Data Exchange (ETDEWEB)

    Regis, F.; Fessia, P.; Bajko, M.; Rijk, G. de [European Organization for Nuclear Research - CERN, CH-1211, Geneve 23 (Switzerland); Manil, P. [CEA/Saclay, IRFU/SIS, 91191 Gif-sur-Yvette (France)

    2010-06-15

    The Short Model Coil (SMC) working group was set in February 2007 within the Next European Dipole (NED) program, in order to develop a short-scale model of a Nb{sub 3}Sn dipole magnet. The SMC group comprises four laboratories: CERN/TE-MSC group (CH), CEA/IRFU (FR), RAL (UK) and LBNL (US). The SMC magnet was originally conceived to reach a peak field of about 13 T on conductor, using a 2500 A/mm{sup 2} Powder-In-Tube (PIT) strand. The aim of this magnet device is to study the degradation of the magnetic properties of the Nb{sub 3}Sn cable, by applying different level of pre-stress. To fully satisfy this purpose, a versatile and easy-to-assemble structure has to be realized. The design of the SMC magnet has been developed from an existing dipole magnet, the SD01, designed, built and tested at LBNL with support from CEA. In this paper we will describe the mechanical optimization of the dipole, starting from a conceptual configuration based on a former magnetic analysis. Two and three-dimensional Finite Element Method (FEM) models have been implemented in ANSYS and in CAST3M, aiming at setting the mechanical parameters of the dipole magnet structure, thus fulfilling the design constraints imposed by the materials. (authors)

  2. A model of cumulation of 137Cs in the carp (Cyprinus carpio L.)

    International Nuclear Information System (INIS)

    Kwapulinski, J.; Buszman, A.; Kwapulinska, G.

    1976-01-01

    A model of 137 Cs as accumulation in various stages of carp development is presented. The model includes the influence of body weight and weight increase on 137 Cs concentration. Moreover, an equation is given, illustrating the influence of the activity of bottom sediments and global fallout. The model was checked, using the results of 137 Cs determinations in the years 1965-1970

  3. ITER central solenoid model coil heat treatment complete and assembly started

    International Nuclear Information System (INIS)

    Thome, R.J.; Okuno, K.

    1998-01-01

    A major R and D task in the ITER program is to fabricate a Superconducting Model Coil for the Central Solenoid to establish the design and fabrication methods for ITER size coils and to demonstrate conductor performance. Completion of its components is expected in 1998, to be followed by assembly with structural components and testing in a facility at JAERI

  4. Mechanical Design of the SMC (Short Model Coil) Dipole Magnet

    CERN Document Server

    Regis, F; Fessia, P; Bajko, M; de Rijk, G

    2010-01-01

    The Short Model Coil (SMC) working group was set in February 2007 within the Next European Dipole (NED) program, in order to develop a short-scale model of a Nb$_{3}$Sn dipole magnet. The SMC group comprises four laboratories: CERN/TE-MSC group (CH), CEA/IRFU (FR), RAL (UK) and LBNL (US). The SMC magnet was originally conceived to reach a peak field of about 13 T on conductor, using a 2500 A/mm2 Powder-In-Tube (PIT) strand. The aim of this magnet device is to study the degradation of the magnetic properties of the Nb$_{3}$Sn cable, by applying different level of pre-stress. To fully satisfy this purpose, a versatile and easy-to-assemble structure has to be realized. The design of the SMC magnet has been developed from an existing dipole magnet, the SD01, designed, built and tested at LBNL with support from CEA. In this paper we will describe the mechanical optimization of the dipole, starting from a conceptual configuration based on a former magnetic analysis. Two and three-dimensional Finite Element Method (...

  5. The transfer function model for dynamic response of wet cooling coils

    International Nuclear Information System (INIS)

    Yao Ye; Liu Shiqing

    2008-01-01

    This paper mainly concerned about the dynamic response model of wet cooling coils that is developed by the Laplace transform method. The theoretic equations are firstly established based on the theory of energy conservation. Then, the transfer functions on the transient responses of wet cooling coils have been deduced using the method of Laplace transform. The transfer functions reveal the dynamic relationships between the inlet variables and the outlet ones of the cooling coils. Partial-fraction method and Newton-Raphson method are both used in the inversion of the transfer functions from the s-domain to τ-domain. To make the dynamic model of wet cooling coils more adaptive, RBFNN method is employed to determine the coefficients of heat and mass transfer. Experiments have been done and manifested that the coefficients of heat and mass transfer by RBFNN will be of great value to the validity of the transient response model of wet cooling coils in this study

  6. submitter 16 T Nb$_{3}$Sn Racetrack Model Coil Test Result

    CERN Document Server

    Perez, J C; Bajko, M; Bottura, L; Bordini, B; Chiuchiolo, A; De Rijk, G; Ferracin, P; Feuvrier, J; Grosclaude, P; Juchno, M; Rochepault, E; Rysti, J; Sarasola, X

    2016-01-01

    In the framework of the European project EuCARD, the High Field Magnet project, led by a CERN-CEA collaboration, implied the development of a large aperture Nb$_{3}$Sn dipole magnet called FRESCA2. The magnet uses four double-pancake block-type coils, each about 1.5 m long. In order to characterize strand and cable properties, as well as to qualify the coil fabrication process, CERN started in 2012 the design and fabrication of the Racetrack Model Coil (RMC) magnet, a short model magnet using the same cable as FRESCA2 magnet with only two flat double-pancake coils about 0.8 m long. In 2013, two superconducting coils have been fabricated, making use of two different types of superconductor. In 2014 and 2015, the coils were tested both in a single and in a double-coil configuration in a support structure based on an external aluminum shell pre-loaded with water-pressurized bladders. In this paper, we describe the design of the RMC magnet and its coils, provide the main parameters of the superconductor, and repo...

  7. Quench evolution and hot spot temperature in the ATLAS B0 model coil

    CERN Document Server

    Dudarev, A; Boxman, H; Broggi, F; Dolgetta, N; Juster, F P; Tetteroo, M; ten Kate, H H J

    2004-01-01

    The 9-m long superconducting model coil B0 was built to verify design parameters and exercise the construction of the Barrel Toroid magnet of ATLAS Detector. The model coil has been successfully tested at CERN. An intensive test program to study quench propagation through the coil windings as well as the temperature distribution has been carried out. The coil is well equipped with pickup coils, voltage taps, superconducting quench detectors and temperature sensors. The current is applied up to 24 kA and about forty quenches have been induced by firing internal heaters. Characteristic numbers at full current of 24 kA are a normal zone propagation of 15 m/s in the conductor leading to a turn-to-turn propagation of 0.1 m/s, the entire coil in normal state within 5.5 s and a safe peak temperature in the windings of 85 K. The paper summarizes the quench performance of the B0 coil. Based on this experience the full-size coils are now under construction and first test results are awaited by early 2004. 7 Refs.

  8. Computational fluid dynamics (CFD) using porous media modeling predicts recurrence after coiling of cerebral aneurysms.

    Science.gov (United States)

    Umeda, Yasuyuki; Ishida, Fujimaro; Tsuji, Masanori; Furukawa, Kazuhiro; Shiba, Masato; Yasuda, Ryuta; Toma, Naoki; Sakaida, Hiroshi; Suzuki, Hidenori

    2017-01-01

    This study aimed to predict recurrence after coil embolization of unruptured cerebral aneurysms with computational fluid dynamics (CFD) using porous media modeling (porous media CFD). A total of 37 unruptured cerebral aneurysms treated with coiling were analyzed using follow-up angiograms, simulated CFD prior to coiling (control CFD), and porous media CFD. Coiled aneurysms were classified into stable or recurrence groups according to follow-up angiogram findings. Morphological parameters, coil packing density, and hemodynamic variables were evaluated for their correlations with aneurysmal recurrence. We also calculated residual flow volumes (RFVs), a novel hemodynamic parameter used to quantify the residual aneurysm volume after simulated coiling, which has a mean fluid domain > 1.0 cm/s. Follow-up angiograms showed 24 aneurysms in the stable group and 13 in the recurrence group. Mann-Whitney U test demonstrated that maximum size, dome volume, neck width, neck area, and coil packing density were significantly different between the two groups (P CFD and larger RFVs in the porous media CFD. Multivariate logistic regression analyses demonstrated that RFV was the only independently significant factor (odds ratio, 1.06; 95% confidence interval, 1.01-1.11; P = 0.016). The study findings suggest that RFV collected under porous media modeling predicts the recurrence of coiled aneurysms.

  9. Slip-spring model of entangled rod-coil block copolymers

    Science.gov (United States)

    Wang, Muzhou; Likhtman, Alexei E.; Olsen, Bradley D.

    2015-03-01

    Understanding the dynamics of rod-coil block copolymers is important for optimal design of functional nanostructured materials for organic electronics and biomaterials. Recently, we proposed a reptation theory of entangled rod-coil block copolymers, predicting the relaxation mechanisms of activated reptation and arm retraction that slow rod-coil dynamics relative to coil and rod homopolymers, respectively. In this work, we introduce a coarse-grained slip-spring model of rod-coil block copolymers to further explore these mechanisms. First, parameters of the coarse-grained model are tuned to match previous molecular dynamics simulation results for coils, rods, and block copolymers. For activated reptation, rod-coil copolymers are shown to disfavor configurations where the rod occupies curved portions of the entanglement tube of randomly varying curvature created by the coil ends. The effect of these barriers on diffusion is quantitatively captured by considering one-dimensional motion along an entanglement tube with a rough free energy potential. Finally, we analyze the crossover between the two mechanisms. The resulting dynamics from both mechanisms acting in combination is faster than from each one individually.

  10. A homeostatic-partly dynamic model for Cs-137 in trees

    International Nuclear Information System (INIS)

    Frissel, M. J.

    1994-01-01

    To describe the uptake of Cs-137 (hereafter only called Cs) two types of models seem most promising: the simple concentration ratio model and the homeostatic model. The first one calculates the concentration of Cs in the vegetation from the Cs concentration in the soil by applying a multiplication factor which is often called a transfer factor. There is no dynamics in the system, the transfer factor or concentration ratio is a constant, which may depend on the ecological system under study. It is often applied to annual crops. The second type of model assumes that the Cs/K ratio in the soil determines the Cs/K ratio in the vegetation. Also this model is usually static. By taking into account variations of the Cs/K ratio in the soil with time - e.g. as caused by K fertilization - it can be extended into a dynamic model. (author)

  11. The B00 model coil in the ATLAS Magnet Test Facility

    CERN Document Server

    Dudarev, A; ten Kate, H H J; Anashkin, O P; Keilin, V E; Lysenko, V V

    2001-01-01

    A 1-m size model coil has been developed to investigate the transport properties of the three aluminum-stabilized superconductors used in the ATLAS magnets. The coil, named B00, is also used for debugging the cryogenic, power and control systems of the ATLAS Magnet Test Facility. The coil comprises two double pancakes made of the barrel toroid and end-cap toroid conductors and a single pancake made of the central solenoid conductor. The pancakes are placed inside an aluminum coil casing. The coil construction and cooling conditions are quite similar to the final design of the ATLAS magnets. The B00 coil is well equipped with various sensors to measure thermal and electrodynamic properties of the conductor inside the coils. Special attention has been paid to the study of the current diffusion process and the normal zone propagation in the ATLAS conductors and windings. Special pick-up coils have been made to measure the diffusion at different currents and magnetic field values. (6 refs).

  12. Dynamic Models of Heating and Cooling Coils with One—Dimensional Air Distribution

    Institute of Scientific and Technical Information of China (English)

    WangZijie; G.Krauss

    1993-01-01

    This paper presents the simulation models of the plate-fin,air-to-water(or water vapour) heat exchangers used as air-heating or air-cooling and dehumidifying colis in the HVAC(Heating,Ventilation and AIr-Conditioning)systems.The thermal models are used to calculate the heat exchange between distributing air and coil pipes and outlet temperatures of air and heat or chilled fluid.The aerodynamic models are used to account for the pressure drop of the air crossing the coil tubes,They can also be used to optimize the structres of such coils.The models are based on principal laws of teat and mass conservation and fluid mechanics.They are transparent and easy to use.In our work,a coil is considered as an assembly of numbers of basic elements in which all the state variables are unique.Therefore we can conveniently simulate the coils with different structures and different geometric parameters.Two modular programs TRNSYS(Transient System Simulation)and ESACAP are utilized as supporting softwares which make the programming and simulation greatly simplified.The coil elements and a real coil were simulated.The results were compared with the data offered by the manufacturer(company SOFICA) and also with those obtained using critical methods such as NTU method ,etc.and good agreement is attained.

  13. Insulating process for HT-7U central solenoid model coils

    International Nuclear Information System (INIS)

    Cui Yimin; Pan Wanjiang; Wu Songtao; Wan Yuanxi

    2003-01-01

    The HT-7U superconducting Tokamak is a whole superconducting magnetically confined fusion device. The insulating system of its central solenoid coils is critical to its properties. In this paper the forming of the insulating system and the vacuum-pressure-impregnating (VPI) are introduced, and the whole insulating process is verified under the super-conducting experiment condition

  14. Application of the finite element method in the modelling of coil bundles

    International Nuclear Information System (INIS)

    Shibui, M.; Zatz, I.J.; Bialek, J.M.

    1983-01-01

    Three different FEM approaches are presented and evaluated as viable interpretations of an actual coil, each limited for use within specified parameter ranges. One is based on solid elements with correctly defined properties permitting the accurate representation of the global behavior of a coil bundle. The other two are more complex and are based on the combination of various elements each accounting for a different aspect of coil behavior which are best resolved via multi-level substructuring. The choice of the best model for the job rests with the analyst who must first resolve what the goals of the analysis are and given the parameters of the problem, which models can be used. The basic idea behind these models is the application of a systematic modelling technique requiring a close correspondence between the capability of the FE themselves and the true mechanical behavior of that portion of the coil being simulated. In order to have analytical solutions for confirming the bending and torsional capabilities of these coil bundle FEM, their behavior is studied via several basic examples. Laminated beam behavior which categorizes the structural nature of many conventional coil bundles is also examined in some depth. Also discussed is a generalized computer program that was developed to accept the description of any conventional coil section and determine an effective stiffness for it to be used in FEM. The various methodologies described in this paper should be applicable to any bundled coil design. Although only conventional coils are discussed, with the proper modifications the concepts and techniques presented can be applied to other configurations as well, such as superconductors. (orig./HP)

  15. How much detail is needed in modeling a transcranial magnetic stimulation figure-8 coil: Measurements and brain simulations

    Science.gov (United States)

    Mandija, Stefano; Sommer, Iris E. C.; van den Berg, Cornelis A. T.; Neggers, Sebastiaan F. W.

    2017-01-01

    Background Despite TMS wide adoption, its spatial and temporal patterns of neuronal effects are not well understood. Although progress has been made in predicting induced currents in the brain using realistic finite element models (FEM), there is little consensus on how a magnetic field of a typical TMS coil should be modeled. Empirical validation of such models is limited and subject to several limitations. Methods We evaluate and empirically validate models of a figure-of-eight TMS coil that are commonly used in published modeling studies, of increasing complexity: simple circular coil model; coil with in-plane spiral winding turns; and finally one with stacked spiral winding turns. We will assess the electric fields induced by all 3 coil models in the motor cortex using a computer FEM model. Biot-Savart models of discretized wires were used to approximate the 3 coil models of increasing complexity. We use a tailored MR based phase mapping technique to get a full 3D validation of the incident magnetic field induced in a cylindrical phantom by our TMS coil. FEM based simulations on a meshed 3D brain model consisting of five tissues types were performed, using two orthogonal coil orientations. Results Substantial differences in the induced currents are observed, both theoretically and empirically, between highly idealized coils and coils with correctly modeled spiral winding turns. Thickness of the coil winding turns affect minimally the induced electric field, and it does not influence the predicted activation. Conclusion TMS coil models used in FEM simulations should include in-plane coil geometry in order to make reliable predictions of the incident field. Modeling the in-plane coil geometry is important to correctly simulate the induced electric field and to correctly make reliable predictions of neuronal activation PMID:28640923

  16. How much detail is needed in modeling a transcranial magnetic stimulation figure-8 coil: Measurements and brain simulations.

    Science.gov (United States)

    Petrov, Petar I; Mandija, Stefano; Sommer, Iris E C; van den Berg, Cornelis A T; Neggers, Sebastiaan F W

    2017-01-01

    Despite TMS wide adoption, its spatial and temporal patterns of neuronal effects are not well understood. Although progress has been made in predicting induced currents in the brain using realistic finite element models (FEM), there is little consensus on how a magnetic field of a typical TMS coil should be modeled. Empirical validation of such models is limited and subject to several limitations. We evaluate and empirically validate models of a figure-of-eight TMS coil that are commonly used in published modeling studies, of increasing complexity: simple circular coil model; coil with in-plane spiral winding turns; and finally one with stacked spiral winding turns. We will assess the electric fields induced by all 3 coil models in the motor cortex using a computer FEM model. Biot-Savart models of discretized wires were used to approximate the 3 coil models of increasing complexity. We use a tailored MR based phase mapping technique to get a full 3D validation of the incident magnetic field induced in a cylindrical phantom by our TMS coil. FEM based simulations on a meshed 3D brain model consisting of five tissues types were performed, using two orthogonal coil orientations. Substantial differences in the induced currents are observed, both theoretically and empirically, between highly idealized coils and coils with correctly modeled spiral winding turns. Thickness of the coil winding turns affect minimally the induced electric field, and it does not influence the predicted activation. TMS coil models used in FEM simulations should include in-plane coil geometry in order to make reliable predictions of the incident field. Modeling the in-plane coil geometry is important to correctly simulate the induced electric field and to correctly make reliable predictions of neuronal activation.

  17. How much detail is needed in modeling a transcranial magnetic stimulation figure-8 coil: Measurements and brain simulations.

    Directory of Open Access Journals (Sweden)

    Petar I Petrov

    Full Text Available Despite TMS wide adoption, its spatial and temporal patterns of neuronal effects are not well understood. Although progress has been made in predicting induced currents in the brain using realistic finite element models (FEM, there is little consensus on how a magnetic field of a typical TMS coil should be modeled. Empirical validation of such models is limited and subject to several limitations.We evaluate and empirically validate models of a figure-of-eight TMS coil that are commonly used in published modeling studies, of increasing complexity: simple circular coil model; coil with in-plane spiral winding turns; and finally one with stacked spiral winding turns. We will assess the electric fields induced by all 3 coil models in the motor cortex using a computer FEM model. Biot-Savart models of discretized wires were used to approximate the 3 coil models of increasing complexity. We use a tailored MR based phase mapping technique to get a full 3D validation of the incident magnetic field induced in a cylindrical phantom by our TMS coil. FEM based simulations on a meshed 3D brain model consisting of five tissues types were performed, using two orthogonal coil orientations.Substantial differences in the induced currents are observed, both theoretically and empirically, between highly idealized coils and coils with correctly modeled spiral winding turns. Thickness of the coil winding turns affect minimally the induced electric field, and it does not influence the predicted activation.TMS coil models used in FEM simulations should include in-plane coil geometry in order to make reliable predictions of the incident field. Modeling the in-plane coil geometry is important to correctly simulate the induced electric field and to correctly make reliable predictions of neuronal activation.

  18. Modeling of an once through helical coil steam generator of a superheated cycle for sizing analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeon Sik; Sim, Yoon Sub; Kim, Eui Kwang [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-12-31

    A thermal sizing code, named as HSGSA (Helical coil Steam Generator Sizing Analyzer), for a sodium heated helical coil steam generator is developed for KALIMER (Korea Advanced LIquid MEtal Reactor) design. The theoretical modeling of the shell and tube sides is described and relevant correlations are presented. For assessment of HSGSA, a reference plant design case is compared to the calculational outputs from HSGSA simulation. 9 refs., 6 figs. (Author)

  19. Modeling of an once through helical coil steam generator of a superheated cycle for sizing analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeon Sik; Sim, Yoon Sub; Kim, Eui Kwang [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    A thermal sizing code, named as HSGSA (Helical coil Steam Generator Sizing Analyzer), for a sodium heated helical coil steam generator is developed for KALIMER (Korea Advanced LIquid MEtal Reactor) design. The theoretical modeling of the shell and tube sides is described and relevant correlations are presented. For assessment of HSGSA, a reference plant design case is compared to the calculational outputs from HSGSA simulation. 9 refs., 6 figs. (Author)

  20. In vitro study of near-wall flow in a cerebral aneurysm model with and without coils.

    Science.gov (United States)

    Goubergrits, L; Thamsen, B; Berthe, A; Poethke, J; Kertzscher, U; Affeld, K; Petz, C; Hege, H-C; Hoch, H; Spuler, A

    2010-09-01

    Coil embolization procedures change the flow conditions in the cerebral aneurysm and, therefore, in the near-wall region. Knowledge of these flow changes may be helpful to optimize therapy. The goal of this study was to investigate the effect of the coil-packing attenuation on the near-wall flow and its variability due to differences in the coil structure. An enlarged transparent model of an ACA aneurysm was fabricated on the basis of CT angiography. The near-wall flow was visualized by using a recently proposed technique called Wall-PIV. Coil-packing attenuation of 10%, 15%, and 20% were investigated and compared with an aneurysmal flow without coils. Then the flow variability due to the coil introduction was analyzed in 10 experiments by using a packing attenuation of 15%. A small packing attenuation of 10% already alters the near-wall flow significantly in a large part of the aneurysmal sac. These flow changes are characterized by a slow flow with short (interrupted) path lines. An increased packing attenuation expands the wall area exposed to the altered flow conditions. This area, however, depends on the coil position and/or on the 3D coil structure in the aneurysm. To our knowledge, this is the first time the near-wall flow changes caused by coils in an aneurysm model have been visualized. It can be concluded that future hydrodynamic studies of coil therapy should include an investigation of the coil structure in addition to the coil-packing attenuation.

  1. Compartmental Model For Uptake Of 137cs By Pine In Forest Soil ...

    African Journals Online (AJOL)

    A compartmental model of soil to pine tree transfer of 137Cs following the Chernobyl nuclear accident is presented. The model was validated using data collected in 1996 at five sites in Northern Ukraine. The transfer constants of 137Cs between model compartments are estimated using a semi-empirical method.

  2. Spontaneous adsorption of coiled-coil model peptides K and E to a mixed lipid bilayer.

    Science.gov (United States)

    Pluhackova, Kristyna; Wassenaar, Tsjerk A; Kirsch, Sonja; Böckmann, Rainer A

    2015-03-26

    A molecular description of the lipid-protein interactions underlying the adsorption of proteins to membranes is crucial for understanding, for example, the specificity of adsorption or the binding strength of a protein to a bilayer, or for characterizing protein-induced changes of membrane properties. In this paper, we extend an automated in silico assay (DAFT) for binding studies and apply it to characterize the adsorption of the model fusion peptides E and K to a mixed phospholipid/cholesterol membrane using coarse-grained molecular dynamics simulations. In addition, we couple the coarse-grained protocol to reverse transformation to atomistic resolution, thereby allowing to study molecular interactions with high detail. The experimentally observed differential binding of the peptides E and K to membranes, as well as the increased binding affinity of helical over unstructered peptides, could be well reproduced using the polarizable Martini coarse-grained (CG) force field. Binding to neutral membranes is shown to be dominated by initial binding of the positively charged N-terminus to the phospholipid headgroup region, followed by membrane surface-aligned insertion of the peptide at the interface between the hydrophobic core of the membrane and its polar headgroup region. Both coarse-grained and atomistic simulations confirm a before hypothesized snorkeling of lysine side chains for the membrane-bound state of the peptide K. Cholesterol was found to be enriched in peptide vicinity, which is probably of importance for the mechanism of membrane fusion. The applied sequential multiscale method, using coarse-grained simulations for the slow adsorption process of peptides to membranes followed by backward transformation to atomistic detail and subsequent atomistic simulations of the preformed peptide-lipid complexes, is shown to be a versatile approach to study the interactions of peptides or proteins with biomembranes.

  3. Modelling of Moving Coil Actuators in Fast Switching Valves Suitable for Digital Hydraulic Machines

    DEFF Research Database (Denmark)

    Nørgård, Christian; Roemer, Daniel Beck; Bech, Michael Møller

    2015-01-01

    an estimation of the eddy currents generated in the actuator yoke upon current rise, as they may have significant influence on the coil current response. The analytical model facilitates fast simulation of the transient actuator response opposed to the transient electro-magnetic finite element model which......The efficiency of digital hydraulic machines is strongly dependent on the valve switching time. Recently, fast switching have been achieved by using a direct electromagnetic moving coil actuator as the force producing element in fast switching hydraulic valves suitable for digital hydraulic...... machines. Mathematical models of the valve switching, targeted for design optimisation of the moving coil actuator, are developed. A detailed analytical model is derived and presented and its accuracy is evaluated against transient electromagnetic finite element simulations. The model includes...

  4. Modeling radionuclide Cs and C dynamics in an artificial forest ecosystem in Japan -FoRothCs ver1.0-

    Directory of Open Access Journals (Sweden)

    Kazuya eNishina

    2015-09-01

    Full Text Available Predicting the environmental fate of Cs radionuclides in forest ecosystems is important for the effective management and assessment of radioactively contaminated forest areas. A large proportion of the radioactively contaminated areas in Japan consist of forest ecosystems, and most of these areas are artificial forests that are used for timber production (e.g., Japanese cedar (Cryptomeria japonica and red pine (Pinus densiflora. Determining the long-term redistribution of 137Cs in forest ecosystems is important for estimating human doses and understanding the ecological impacts and challenges associated with managing contaminated forests. To facilitate the management and 137Cs decontamination of these forests, we developed a new open-source 137Cs cycling model, ForRothCs, that considers C cycling within forests, as well as biomass production and soil decomposition processes. For the 137Cs inventory, this model estimates the dynamics (Bq m−2 and activity (Bq kg−2 of 137Cs on a decadal time scale, primarily in the leaves, branches, stems, litter layer, and the soil. This model is based on the biomass production and the dynamics of the C cycle models. We tested the model by considering a simple scenario of forest management, i.e., thinning and harvesting, for the first five years following a fallout event. The results showed that these activities have a limited impact on the 137Cs inventory due to the rapid migration of 137Cs from vegetation to soil. Our projections also showed the examined forest management practices resulted in reduced litterfall, which in turn reduced C input to the forest floor and increased the concentration of 137Cs in the litterfall and soil organic layer. Although further validation of the ForRothCs model is required using field observation data, the model can be used to evaluate long-term 137Cs dynamics associated with commonly used forest and decontamination management scenarios.

  5. Analytical model of tilted driver–pickup coils for eddy current nondestructive evaluation

    Science.gov (United States)

    Cao, Bing-Hua; Li, Chao; Fan, Meng-Bao; Ye, Bo; Tian, Gui-Yun

    2018-03-01

    A driver-pickup probe possesses better sensitivity and flexibility due to individual optimization of a coil. It is frequently observed in an eddy current (EC) array probe. In this work, a tilted non-coaxial driver-pickup probe above a multilayered conducting plate is analytically modeled with spatial transformation for eddy current nondestructive evaluation. Basically, the core of the formulation is to obtain the projection of magnetic vector potential (MVP) from the driver coil onto the vector along the tilted pickup coil, which is divided into two key steps. The first step is to make a projection of MVP along the pickup coil onto a horizontal plane, and the second one is to build the relationship between the projected MVP and the MVP along the driver coil. Afterwards, an analytical model for the case of a layered plate is established with the reflection and transmission theory of electromagnetic fields. The calculated values from the resulting model indicate good agreement with those from the finite element model (FEM) and experiments, which validates the developed analytical model. Project supported by the National Natural Science Foundation of China (Grant Nos. 61701500, 51677187, and 51465024).

  6. A Simplified Model to Calculate AC Losses in Large 2G HTS Coils

    DEFF Research Database (Denmark)

    Song, Xiaowei (Andy); Mijatovic, Nenad; Jensen, Bogi Bech

    2015-01-01

    . The model presented uses H formulation which directly solves magnetic fields, and the general partial differential equations (PDEs) module in Comsol Multiphysics is used to implement the model. Afterwards, the model is used to simulate the excitation stage of a racetrack HTS coil with 350 tapes. The AC...

  7. Basic model for the prediction of 137Cs concentration in the organisms of detritus food chain

    International Nuclear Information System (INIS)

    Tateda, Yuzuru

    1997-01-01

    In order to predict 137 Cs concentrations in marine organisms for monitoring, a basic model for the prediction of nuclide levels in marine organisms of detritus food chain was studied. The equilibrated values of ( 137 Cs level in organism)/( 137 Cs level in seawater) derived from calculation agreed with the observed data, indicating validity of modeling conditions. The result of simulation by this basic model showed the following conclusions. 1) ''Ecological half-life'' of 137 Cs in organisms of food chain were 35 and 130 days for detritus feeder and benthic teleosts, respectively, indicating that there was no difference of the ecological half lives in organisms between in detritus food chain and in other food chains. 2) The 137 Cs concentration in organisms showed a peak at 18 and 100 days in detritus and detritus feeder, respectively, after the introduction of 137 Cs into environmental seawater. Their concentration ratios to 137 Cs peak level in seawater were within a range of 2.7-3.8, indicating insignificant difference in the response to 137 Cs change in seawater between in the organisms of detritus food chain and of other food chain. 3) The basic model studies makes it available that the prediction of 137 Cs level in organisms of food chain can be simulated in coastal ecosystem. (author)

  8. Experimental studies of Cs, Sr, Ni, and Eu sorption on Na-illite and the modelling of Cs sorption

    International Nuclear Information System (INIS)

    Poinssot, C.; Baeyens, B.; Bradbury, M.H.

    1999-08-01

    A natural illite (illite du Puy) was purified and converted to the homo-ionic Na-form. The conditioned Na-illite was characterised in terms of its mineralogy, chemical inventory and physico-chemical properties. The structural formula was determined from energy dispersive spectroscopic analyses (SEM/TEM-EDS) and bulk chemistry measurements. A cation exchange capacity of 127 meq kg -1 was determined by the 22 Na isotope dilution method at neutral pH. The Na-CEC was also measured as a function of pH. The stability of Na-illite as a function of pH in the range between 3 and 6 was investigated. At low pH values partial dissolution of the illite occurs releasing the structural elements Al, Si, Mg, and K into solution. The presence of Ca and Sr in solution was interpreted as being due to desorption from cation exchange sites. All of these elements are also present at neutral pH but at considerably lower levels. Such effects cannot be avoided and must be considered in the interpretation of the sorption measurements. The main focus of the experimental work presented here is on the sorption behaviour of Cs, Sr, Ni and Eu on conditioned Na-illite as a function of NaClO 4 background electrolyte concentration (0.1 and 0.01 M), nuclide concentration and pH in the range between 3 and 11. Sorption edge data (R d versus pH) and sorption isotherms (quantity of nuclide sorbed versus equilibrium nuclide concentration) are presented for these four elements. Prior to beginning these experiments, sorption kinetics were measured. The broad based pool of sorption measurements generated from this work will provide the source data sets for subsequent modelling. So far only the Cs sorption measurements have been modelled. A two site cation exchange model was developed to describe the sorption of Cs over the whole range of experimental conditions. The two site types were termed 'frayed edge sites' (FES, high affinity/low capacity) and 'type II sites' (low affinity/high capacity). Selectivity

  9. A homeostatic-partly dynamic model for 137Cs in trees

    International Nuclear Information System (INIS)

    Frissel, M.

    1994-01-01

    A model has been developed to describe the behaviour of 137 Cs in trees. The core of the model is the assumption that 137 Cs/K ratio in soil determines the 137 Cs/K ratio in various parts of a tree. This is an equilibrium model but taking into account the time dependence of Cs/K ratio in the soil (caused by K-fertilization) it has been extended to a dynamic model. The model desribes a growing tree. Four compartments are considered: soil; easily accessible parts of the tree; woody parts difficult to access; fruits or leaves. The model is homeostatic, i.e. all 137 Cs concentrations and fluxes are controlled by K concentrations and fluxes, respectively. The addition of K-fertilizer to the soil manifests itself in an immediate change of the Cs/K ratio in the soil and in the easily accessible plant parts, but only slowly - in the woody parts. Also an excess of Cs in the woody part is only slowly released. Important processes are the discrimination between Cs and K and the luxurious consumption of K. The cycling of K in the system (throughput of K via falling leaves, branches, etc.) is also important. Furthermore, a good insight in accessibility of the various parts of the tree seems required, the division in only three compartments, as in the model is probably unsufficient. (author)

  10. Fixation of Cs to marine sediments estimated by a stochastic modelling approach.

    Science.gov (United States)

    Børretzen, Peer; Salbu, Brit

    2002-01-01

    Dumping of nuclear waste in the Kara Sea represents a potential source of radioactive contamination to the Arctic Seas in the future. The mobility of 137Cs ions leached from the waste will depend on the interactions with sediment particles. Whether sediments will act as a continuous permanent sink for released 137Cs, or contaminated sediments will serve as a diffuse source of 137Cs in the future, depends on the interaction kinetics and binding mechanisms involved. The main purpose of this paper is to study the performance of different stochastic models using kinetic information to estimate the time needed for Cs ions to become irreversibly fixed within the sediments. The kinetic information was obtained from 134Cs tracer sorption and desorption (sequential extractions) experiments, conducted over time, using sediments from the Stepovogo Fjord waste dumping site, on the east coast of Novaya Zemlya. Results show that 134Cs ions interact rapidly with the surfaces of the Stepovogo sediment, with an estimated distribution coefficient Kd(eq) of 300 ml/g (or 13m2/g), and the 134Cs ions are increasingly irreversibly fixed to the sediment over time. For the first time, stochastic theory has been utilised for sediment-seawater systems to estimate the mean residence times (MRTs) of Cs ions in operationally defined sediment phases described by compartment models. In the present work, two different stochastic models (i) a Markov process model (MP) being analogous to deterministic compartment models, and (ii) a semi-Markov process model (SMP) which should be physically more relevant for inhomogeneous systems, have been compared. As similar results were obtained using the two models, the less complicated MP model was utilised to predict the time needed for an average Cs ion to become irreversibly fixed in the Stepovogo sediments. According the model, approximately 1100 days of contact time between Cs ions and sediments is needed before 50% of the 134Cs ion becomes fixed in the

  11. Physical Modeling of the Polyfrequency Filter-Compensating Device Based on the Capacitor-Coil

    Science.gov (United States)

    Butyrin, P. A.; Gusev, G. G.; Mikheev, D. V.; Shakirzianov, F. N.

    2017-12-01

    The paper presents the results of physical modeling and experimental study of the frequency characteristics of the polyfrequency filter-compensating device (PFCD) based on a capacitor-coil. The amplitude- frequency and phase-frequency characteristics of the physical PFCD model were constructed and its equivalent parameters were identified. The feasibility of a PFCD in the form of a single technical device with high technical and economic characteristics was experimentally proven. In the paper, recommendations for practical applications of the capacitor-coil-based PFCD are made and the advantages of the device over known standard passive filter-compensating devices are evaluated.

  12. Intersegment interactions and helix-coil transition within the generalized model of polypeptide chains approach

    Science.gov (United States)

    Badasyan, A. V.; Hayrapetyan, G. N.; Tonoyan, Sh. A.; Mamasakhlisov, Y. Sh.; Benight, A. S.; Morozov, V. F.

    2009-09-01

    The generalized model of polypeptide chains is extended to describe the helix-coil transition in a system comprised of two chains interacting side-by-side. The Hamiltonian of the model takes into account four possible types of interactions between repeated units of the two chains, i.e., helix-helix, helix-coil, coil-helix, and coil-coil. Analysis reveals when the energy Ihh+Icc of (h-h, c-c) interactions overwhelms the energy Ihc+Ich of mixed (h-c, c-h) interactions, the correlation length rises substantially, resulting in narrowing of the transition interval. In the opposite case, when Ihh+Icc

  13. A simplified 137Cs transport model for estimating erosion rates in undisturbed soil

    International Nuclear Information System (INIS)

    Zhang Xinbao; Long Yi; He Xiubin; Fu Jiexiong; Zhang Yunqi

    2008-01-01

    137 Cs is an artificial radionuclide with a half-life of 30.12 years which released into the environment as a result of atmospheric testing of thermo-nuclear weapons primarily during the period of 1950s-1970s with the maximum rate of 137 Cs fallout from atmosphere in 1963. 137 Cs fallout is strongly and rapidly adsorbed by fine particles in the surface horizons of the soil, when it falls down on the ground mostly with precipitation. Its subsequent redistribution is associated with movements of the soil or sediment particles. The 137 Cs nuclide tracing technique has been used for assessment of soil losses for both undisturbed and cultivated soils. For undisturbed soils, a simple profile-shape model was developed in 1990 to describe the 137 Cs depth distribution in profile, where the maximum 137 Cs occurs in the surface horizon and it exponentially decreases with depth. The model implied that the total 137 Cs fallout amount deposited on the earth surface in 1963 and the 137 Cs profile shape has not changed with time. The model has been widely used for assessment of soil losses on undisturbed land. However, temporal variations of 137 Cs depth distribution in undisturbed soils after its deposition on the ground due to downward transport processes are not considered in the previous simple profile-shape model. Thus, the soil losses are overestimated by the model. On the base of the erosion assessment model developed by Walling, D.E., He, Q. [1999. Improved models for estimating soil erosion rates from cesium-137 measurements. Journal of Environmental Quality 28, 611-622], we discuss the 137 Cs transport process in the eroded soil profile and make some simplification to the model, develop a method to estimate the soil erosion rate more expediently. To compare the soil erosion rates calculated by the simple profile-shape model and the simple transport model, the soil losses related to different 137 Cs loss proportions of the reference inventory at the Kaixian site of the

  14. Simple model for the description of a thermionic Cs diode in operation

    International Nuclear Information System (INIS)

    Tschersich, K.G.

    1975-01-01

    Because of the small voltage loss in the space between the electrodes, Cs is the most common work medium in thermionic diodes. With the model calculations of the processes in the space between the electrodes, the author aims to explain the formation of Cs ions and the current transport through the electrode gap at these low voltages. (RW/AK) [de

  15. Prognosis of Cs 137 dynamics in Pripyat river using mathematical modeling

    International Nuclear Information System (INIS)

    Ris, T.V.

    2010-01-01

    The analysis of measured and predicted data of Cs 137 dynamics in the water of Pripyat River are given using mathematical models developed by J. Smith (AQUASCOPE), L. Hakanson, and proposed transport model. (authors)

  16. 137Cs applicability to soil erosion assessment: theoretical and empirical model

    International Nuclear Information System (INIS)

    Andrello, Avacir Casanova

    2004-02-01

    The soil erosion processes acceleration and the increase of soil erosion rates due to anthropogenic perturbation in soil-weather-vegetation equilibrium has influenced in the soil quality and environment. So, the possibility to assess the amplitude and severity of soil erosion impact on the productivity and quality of soil is important so local scale as regional and global scale. Several models have been developed to assess the soil erosion so qualitative as quantitatively. 137 Cs, an anthropogenic radionuclide, have been very used to assess the superficial soil erosion process Empirical and theoretical models were developed on the basis of 137 Cs redistribution as indicative of soil movement by erosive process These models incorporate many parameters that can influence in the soil erosion rates quantification by 137 Cs redistribution. Statistical analysis was realized on the models recommended by IAEA to determinate the influence that each parameter generates in results of the soil redistribution. It was verified that the most important parameter is the 137 Cs redistribution, indicating the necessity of a good determination in the 137 Cs inventory values with a minimum deviation associated with these values. After this, it was associated a 10% deviation in the reference value of 137 Cs inventory and the 5% in the 137 Cs inventory of the sample and was determinate the deviation in results of the soil redistribution calculated by models. The results of soil redistribution was compared to verify if there was difference between the models, but there was not difference in the results determinate by models, unless above 70% of 137 Cs loss. Analyzing three native forests and an area of the undisturbed pasture in the Londrina region, can be verified that the 137 Cs spatial variability in local scale was 15%. Comparing the 137 Cs inventory values determinate in the three native forest with the 137 Cs inventory value determinate in the area of undisturbed pasture in the

  17. Modeling and sizing the coil in boost converters dedicated to photovoltaic sources

    Science.gov (United States)

    Atik, Lotfi; Fares, Mohammed Amine; Zaraket, Jean; Bachir, Ghalem; Aillerie, Michel

    2018-05-01

    The coil is a very important element in a wide range of power electrical systems as such as those used in converter or inverter dedicated to extract and to adapt the value and the shape of the intensity and the voltage delivered by renewable energy sources. Thus, knowing its behavior in converters is paramount to obtain a maximum conversion efficiency and reliability. In this context, this paper presents a global study of a DC/DC boost converter dedicated to photovoltaic sources based on the modeling of the behavior of the coil or the inductance as a function of the switching frequency.

  18. {sup 137}Cs applicability to soil erosion assessment: theoretical and empirical model; Aplicabilidade do {sup 137}Cs para medir erosao do solo: modelos teoricos e empiricos

    Energy Technology Data Exchange (ETDEWEB)

    Andrello, Avacir Casanova

    2004-02-15

    The soil erosion processes acceleration and the increase of soil erosion rates due to anthropogenic perturbation in soil-weather-vegetation equilibrium has influenced in the soil quality and environment. So, the possibility to assess the amplitude and severity of soil erosion impact on the productivity and quality of soil is important so local scale as regional and global scale. Several models have been developed to assess the soil erosion so qualitative as quantitatively. {sup 137}Cs, an anthropogenic radionuclide, have been very used to assess the superficial soil erosion process Empirical and theoretical models were developed on the basis of {sup 137} Cs redistribution as indicative of soil movement by erosive process These models incorporate many parameters that can influence in the soil erosion rates quantification by {sup 137} Cs redistribution. Statistical analysis was realized on the models recommended by IAEA to determinate the influence that each parameter generates in results of the soil redistribution. It was verified that the most important parameter is the {sup 137} Cs redistribution, indicating the necessity of a good determination in the {sup 137} Cs inventory values with a minimum deviation associated with these values. After this, it was associated a 10% deviation in the reference value of {sup 137} Cs inventory and the 5% in the {sup 137} Cs inventory of the sample and was determinate the deviation in results of the soil redistribution calculated by models. The results of soil redistribution was compared to verify if there was difference between the models, but there was not difference in the results determinate by models, unless above 70% of {sup 137} Cs loss. Analyzing three native forests and an area of the undisturbed pasture in the Londrina region, can be verified that the {sup 137} Cs spatial variability in local scale was 15%. Comparing the {sup 137} Cs inventory values determinate in the three native forest with the {sup 137} Cs inventory

  19. The SMC (Short Model Coil) Nb$_{3}$Sn Program: FE Analysis with 3D Modeling

    CERN Document Server

    Kokkinos, C; Guinchard, M; Karppinen, M; Manil, P; Perez, J C; Regis, F

    2012-01-01

    The SMC (Short Model Coil) project aims at testing superconducting coils in racetrack configuration, wound with Nb$_{3}$Sn cable. The degradation of the magnetic properties of the cable is studied by applying different levels of pre-stress. It is an essential step in the validation of procedures for the construction of superconducting magnets with high performance conductor. Two SMC assemblies have been completed and cold tested in the frame of a European collaboration between CEA (FR), CERN and STFC (UK), with the technical support from LBNL (US). The second assembly showed remarkable good quench results, reaching a peak field of 12.5T. This paper details the new 3D modeling method of the SMC, implemented using the ANSYS® Workbench environment. Advanced computer-aided-design (CAD) tools are combined with multi-physics Finite Element Analyses (FEA), in the same integrated graphic interface, forming a fully parametric model that enables simulation driven development of the SMC project. The magnetic and struct...

  20. A quantitative model for estimating mean annual soil loss in cultivated land using 137Cs measurements

    International Nuclear Information System (INIS)

    Yang Hao; Zhao Qiguo; Du Mingyuan; Minami, Katsuyuki; Hatta, Tamao

    2000-01-01

    The radioisotope 137 Cs has been widely used to determine rates of cultivated soil loss, Many calibration relationships (including both empirical relationships and theoretical models) have been employed to estimate erosion rates from the amount of 137 Cs lost from the cultivated soil profile. However, there are important limitations which restrict the reliability of these models, which consider only the uniform distribution of 137 Cs in the plough layer and the depth. As a result, erosion rates they may be overestimated or underestimated. This article presents a quantitative model for the relation the amount of 137 Cs lost from the cultivate soil profile and the rate of soil erosion. According to a mass balance model, during the construction of this model we considered the following parameters: the remaining fraction of the surface enrichment layer (F R ), the thickness of the surface enrichment layer (H s ), the depth of the plough layer (H p ), input fraction of the total 137 Cs fallout deposition during a given year t (F t ), radioactive decay of 137 Cs (k), and sampling year (t). The simulation results showed that the amounts of erosion rates estimated using this model were very sensitive to changes in the values of the parameters F R , H s , and H p . We also observed that the relationship between the rate of soil loss and 137 Cs depletion is neither linear nor logarithmic, and is very complex. Although the model is an improvement over existing approaches to derive calibration relationships for cultivated soil, it requires empirical information on local soil properties and the behavior of 137 Cs in the soil profile. There is clearly still a need for more precise information on the latter aspect and, in particular, on the retention of 137 Cs fallout in the top few millimeters of the soil profile and on the enrichment and depletion effects associated with soil redistribution (i.e. for determining accurate values of F R and H s ). (author)

  1. Modeling of Heat Transfer in the Helical-Coil Heat Exchanger for the Reactor Facility "UNITERM"

    Directory of Open Access Journals (Sweden)

    V. I. Solonin

    2014-01-01

    Full Text Available Circuit heat sink plays an important role in the reactor system. Therefore it imposes high requirements for quality of determining thermal-hydraulic parameters. This article is aimed at modeling of heat exchange process of the helical-coil heat exchanger, which is part of the heat sink circuit of the reactor facility "UNITERM."The simulation was performed using hydro-gas-dynamic software package ANSYS CFX. Computational fluid dynamics of this package allows us to perform calculations in a threedimensional setting, giving an idea of the fluid flow nature. The purpose of the simulation was to determine the parameters of the helical-coil heat exchanger (temperature, velocity at the outlet of the pipe and inter-tubular space, pressure drop, and the nature of the fluid flow of primary and intermediate coolants. Geometric parameters of the model were determined using the preliminary calculations performed by the criterion equations. In calculations Turbulence models k-ε RNG, Shear Stress Transport (SST are used. The article describes selected turbulence models, and considers relationship with wall function.The calculation results allow us to give the values obtained for thermal-hydraulic parameters, to compare selected turbulence models, as well as to show distribution patterns of the coolant temperature, pressure, and velocity at the outlet of the intermediate cooler.Calculations have shown that:- maximum values of primary coolant temperature at the outlet of the heat exchanger surface are encountered in the space between the helical-coil tubes;- higher temperatures of intermediate coolant at the outlet of the coils (in space of helicalcoil tubes are observed for the peripheral row;- primary coolant movement in the inter-tubular space of helical-coil surface is formed as a spiral flow, rather than as a in-line tube bank cross flow.

  2. Development of a single-layer Nb3Sn common coil dipole model

    Energy Technology Data Exchange (ETDEWEB)

    Igor Novitski et al.

    2002-12-13

    A high-field dipole magnet based on the common coil design was developed at Fermilab for a future Very Large Hadron Collider. A short model of this magnet with a design field of 11 T in two 40-mm apertures is being fabricated using the react-and-wind technique. In order to study and optimize the magnet design two 165-mm long mechanical models were assembled and tested. A technological model consisting of magnet straight section and ends was also fabricated in order to check the tooling and the winding and assembly procedures. This paper describes the design and technology of the common coil dipole magnet and summarizes the status of short model fabrication.The results of the mechanical model tests and comparison with FE mechanical analysis are also presented.

  3. Modelling the distribution of 90Sr and 137Cs in the Mediterranean Sea (MTPII-MATER)

    International Nuclear Information System (INIS)

    Sanchez-Cabeza, J.A.; Ortega, M.; Fernandez, V.; Tintore, J.; Monaco, A.

    1999-01-01

    Within the frame of the MTPII-MATER project (MAST), the distribution of 90 Sr and 137 Cs in the Mediterranean Sea was modelled, as these radionuclides are useful tracers of water circulation. The Mediterranean Sea was divided into 81 boxes, corresponding to 21 regions, taking into account water mass circulation, bathymetry and data availability. Transfer rates were obtained from the MOM model run under MEDMEX conditions. The model was run with realistic inputs, which included weapons global fallout, Chernobyl 137 Cs, nuclear industry and river runoff. It was observed that existing data are scarce, especially in the eastern Mediterranean. In general, model predictions agreed well with observations, showing maximum concentrations in surface waters and maxima due to global fallout ( 137 Cs and 90 Sr) and to the Chernobyl accident ( 137 Cs only). (author)

  4. A tokamak with nearly uniform coil stress based on virial theorem

    International Nuclear Information System (INIS)

    Tsutsui, H.

    2002-01-01

    A novel tokamak concept with a new type of toroidal field (TF) coils and a central solenoid (CS) whose stress is much reduced to a theoretical limit determined by the virial theorem has been devised. Recently, we had developed a tokamak with force-balanced coils (FBCs) which are multi-pole helical hybrid coils combining TF coils and a CS coil. The combination reduces the net electromagnetic force in the direction of major radius. In this work, we have extended the FBC concept using the virial theorem. High-field coils should accordingly have same averaged principal stresses in all directions, whereas conventional FBC reduces stress in the toroidal direction only. Using a shell model, we have obtained the poloidal rotation number of helical coils which satisfy the uniform stress condition, and named the coil as virial-limited coil (VLC). VLC with circular cross section of aspect ratio A=2 reduces maximum stress to 60% compared with that of TF coils. In order to prove the advantage of VLC concept, we have designed a small VLC tokamak Todoroki-II. The plasma discharge in Todoroki-II will be presented. (author)

  5. The ITER magnets: Preparation for full size construction based on the results of the model coil programme

    International Nuclear Information System (INIS)

    Huguet, M.

    2003-01-01

    The ITER magnets are long-lead time items and the preparation of their construction is the subject of a major and coordinated effort of the ITER International Team and Participant Teams. The results of the ITER model coil programme constitute the basis and the main source of data for the preparation of the technical specifications for the procurement of the ITER magnets. A review of the salient results of the ITER model coil programme is given and the significance of these results for the preparation of full size industrial production is explained. The model coil programme has confirmed the validity of the design and the manufacturer's ability to produce the coils with the required quality level. The programme has also allowed the optimisation of the conductor design and the identification of further development which would lead to cost reductions of the toroidal field coil case. (author)

  6. Molecular basis of coiled-coil oligomerization-state specificity.

    Science.gov (United States)

    Ciani, Barbara; Bjelic, Saša; Honnappa, Srinivas; Jawhari, Hatim; Jaussi, Rolf; Payapilly, Aishwarya; Jowitt, Thomas; Steinmetz, Michel O; Kammerer, Richard A

    2010-11-16

    Coiled coils are extensively and successfully used nowadays to rationally design multistranded structures for applications, including basic research, biotechnology, nanotechnology, materials science, and medicine. The wide range of applications as well as the important functions these structures play in almost all biological processes highlight the need for a detailed understanding of the factors that control coiled-coil folding and oligomerization. Here, we address the important and unresolved question why the presence of particular oligomerization-state determinants within a coiled coil does frequently not correlate with its topology. We found an unexpected, general link between coiled-coil oligomerization-state specificity and trigger sequences, elements that are indispensable for coiled-coil formation. By using the archetype coiled-coil domain of the yeast transcriptional activator GCN4 as a model system, we show that well-established trimer-specific oligomerization-state determinants switch the peptide's topology from a dimer to a trimer only when inserted into the trigger sequence. We successfully confirmed our results in two other, unrelated coiled-coil dimers, ATF1 and cortexillin-1. We furthermore show that multiple topology determinants can coexist in the same trigger sequence, revealing a delicate balance of the resulting oligomerization state by position-dependent forces. Our experimental results should significantly improve the prediction of the oligomerization state of coiled coils. They therefore should have major implications for the rational design of coiled coils and consequently many applications using these popular oligomerization domains.

  7. Specific activity and concentration model applied to 137Cs movement in a eutrophic lake

    International Nuclear Information System (INIS)

    Vanderploeg, H.A.; Booth, R.S.; Clark, F.H.

    1976-01-01

    A linear systems-analysis model which simulates time-dependent dynamics of specific activity and concentration of radiocesium in lake ecosystems was applied to a shallow, eutrophic lake that had received a pulse input of 137 Cs. Best estimates of transfer coefficients for abiotic compartments (sediment, interstitial water and lake water) and the macrophyte compartment which controlled the mass balance of cesium in water were determined by ''tuning'' our initial estimates of the transfer coefficients to observed data on 137 Cs concentrations and contents of these compartments. In most cases, the optimized transfer coefficients for the abiotic compartments were not greatly different from our independently derived initial estimates, and the simulations for optimized coefficients were close to those based on initial estimates. The 137 Cs concentrations in water as predicted by the optimized transfer coefficients were then used to calculate 137 Cs kinetics in biota other than macrophytes. In general, model simulations were close to concentrations observed in the biota. The agreement between 137 Cs concentrations and simulations in bottom invertebrates supported our assumption that bottom sediments are not a major source of Cs to the biota. Our specific activity and concentration model was compared to the radionuclide content model, the model used in terrestrial ecosystems. For biotic components of aquatic ecosystems, values of α/sub ij/, the transfer coefficients of our model, are easily estimated from turnover rates of radiocesium in individual organisms in the laboratory

  8. Modelling of flexi-coil springs with rubber-metal pads in a locomotive running gear

    Directory of Open Access Journals (Sweden)

    Michálek T.

    2015-06-01

    Full Text Available Nowadays, flexi-coil springs are commonly used in the secondary suspension stage of railway vehicles. Lateral stiffness of these springs is influenced by means of their design parameters (number of coils, height, mean diameter of coils, wire diameter etc. and it is often suitable to modify this stiffness in such way, that the suspension shows various lateral stiffness in different directions (i.e., longitudinally vs. laterally in the vehicle-related coordinate system. Therefore, these springs are often supplemented with some kind of rubber-metal pads. This paper deals with modelling of the flexi-coil springs supplemented with tilting rubber-metal tilting pads applied in running gear of an electric locomotive as well as with consequences of application of that solution of the secondary suspension from the point of view of the vehicle running performance. This analysis is performed by means of multi-body simulations and the description of lateral stiffness characteristics of the springs is based on results of experimental measurements of these characteristics performed in heavy laboratories of the Jan Perner Transport Faculty of the University of Pardubice.

  9. Analytical Model of Coil Spring Damper Based on the Loading Test

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Sung Gook; Park, Woong Ki [INNOSE TECH Co. LTD, Incheon (Korea, Republic of); Furuya, Osamu [Tokyo City University, Tokyo (Japan); Kurabayashi, Hiroshi [Vibro-System, Tokyo (Japan)

    2016-05-15

    The one way of solving such problems is to enhance and to develop an improved damping element used in base-isolation and response control system. A cost reduction of damper for a large scale structure is another important task to upgrade the total response control abilities in the near future. This study has examined a response control device using elastoplastic hysteresis damping of metal material. The proposed damper is designed to be coil spring element shape for a uniform stress of metal and for a reduction of low cyclic fatigue in large deformation to upgrade a repetitive strength during the earthquake motions. By using the metal material of SS400 general structural rolled steel, the corresponding cost issues of the damping element will be effectively reduced. The analytical of elasto-plastic coil spring damper (CSD) is introduced, and basic mechanical properties evaluated experimentally and analytically. This study has been examined the response control damper using elasto-plastic hysteresis characteristics of metal material. The paper described the design method of elasto-plastic coil spring damper, basic mechanical properties evaluated from loading test, and analytical model of damper are summarized. It was confirmed that the damping force and mechanical characteristics of elasto-plastic coil spring damper are almost satisfied the design specifications.

  10. Modeling of coupling mechanism of wireless power transfer system and vibration phenomenon of receiver-coil in three-coil system

    Directory of Open Access Journals (Sweden)

    Suqi Liu

    2017-11-01

    Full Text Available Wireless power transfer (WPT via coupled magnetic resonances has become a focus recently, but the mechanisms responsible for such work are uncertain. We found that WPT system is a self-organization system by utilizing self-organization theory to judge. Firstly, the circuit model was established and transfer characteristic of a system was researched by utilizing circuit theories. Thus, with the introduction of entropy variable S, the energy equation of state can be established from the energy of the transmitter side and the energy of the receiver side. According to the energy equation of state, this paper obtains two equations when the reactance of the transmitter side and the receiver side equate to zero respectively. The vibration phenomenon of the receiver-coil in a three-coil WPT system was predicted and explained. Our findings illuminate the unusual self-organization in the WPT system and explain the vibration phenomenon of the receiver-coil in a three-coil WPT system.

  11. Modeling of coupling mechanism of wireless power transfer system and vibration phenomenon of receiver-coil in three-coil system

    Science.gov (United States)

    Liu, Suqi; Tan, Jianping; Wen, Xue

    2017-11-01

    Wireless power transfer (WPT) via coupled magnetic resonances has become a focus recently, but the mechanisms responsible for such work are uncertain. We found that WPT system is a self-organization system by utilizing self-organization theory to judge. Firstly, the circuit model was established and transfer characteristic of a system was researched by utilizing circuit theories. Thus, with the introduction of entropy variable S, the energy equation of state can be established from the energy of the transmitter side and the energy of the receiver side. According to the energy equation of state, this paper obtains two equations when the reactance of the transmitter side and the receiver side equate to zero respectively. The vibration phenomenon of the receiver-coil in a three-coil WPT system was predicted and explained. Our findings illuminate the unusual self-organization in the WPT system and explain the vibration phenomenon of the receiver-coil in a three-coil WPT system.

  12. A Finite Element Model for Mechanical Analysis of LHC Main Dipole Magnet Coils

    CERN Document Server

    Pojer, Mirko; Scandale, Walter

    2007-01-01

    After years of studies and observations, the mechanical stability of the LHC main dipole magnets still remains an open issue. The robustness of these magnets has already been asserted and their reliability in operation is not far from being proven. However, anomalous mechanical behaviors sometimes observed are not yet completely understood. A finite element model, which has been recently developed at CERN, aims at providing an instrument for better explaining these anomalies. Cable modeling and contact between elements, friction and mechanical hysteresis are the key features of this model. The simulation of the hysteresis experienced by the coil during collaring, presented here, is the starting point for the representation of the whole life cycle of the dipole coil.

  13. A "1"3"7Cs erosion model with moving boundary

    International Nuclear Information System (INIS)

    Yin, Chuan; Ji, Hongbing

    2015-01-01

    A novel quantitative model of the relationship between diffused concentration changes and erosion rates using assessment of soil losses was developed. It derived from the analysis of surface soil "1"3"7Cs flux variation under persistent erosion effect and based on the principle of geochemistry kinetics moving boundary. The new moving boundary model improves the basic simplified transport model (Zhang et al., 2008), and mainly applies to uniform rainfall areas which show a long-time soil erosion. The simulation results for this kind of erosion show under a long-time soil erosion, the influence of "1"3"7Cs concentration will decrease exponentially with increasing depth. Using the new model fit to the measured "1"3"7Cs depth distribution data in Zunyi site, Guizhou Province, China which has typical uniform rainfall provided a good fit with R"2 = 0.92. To compare the soil erosion rates calculated by the simple transport model and the new model, we take the Kaixian reference profile as example. The soil losses estimated by the previous simplified transport model are greater than those estimated by the new moving boundary model, which is consistent with our expectations. - Highlights: • The diffused moving boundary principle analysing "1"3"7Cs flux variation. • The new erosion model applies to uniform rainfall areas. • The erosion effect on "1"3"7Cs will decrease exponentially with increasing depth. • The new model provides two methods of calculating erosion rate.

  14. How much detail is needed in modeling a transcranial magnetic stimulation figure-8 coil: Measurements and brain simulations

    OpenAIRE

    Petrov, Petar I.; Mandija, Stefano; Sommer, Iris E. C.; van den Berg, Cornelis A. T.; Neggers, Sebastiaan F. W.

    2017-01-01

    Background: Despite TMS wide adoption, its spatial and temporal patterns of neuronal effects are not well understood. Although progress has been made in predicting induced currents in the brain using realistic finite element models (FEM), there is little consensus on how a magnetic field of a typical TMS coil should be modeled. Empirical validation of such models is limited and subject to several limitations. Methods: We evaluate and empirically validate models of a figure-of-eight TMS coil t...

  15. Modelling of 137Cs behaviour in the soil-plant system following the application of ameliorants

    International Nuclear Information System (INIS)

    Spiridonov, S.; Fesenko, S.; Sanzharova, N.

    2004-01-01

    A set of countermeasures aimed at reducing 137 Cs uptake by plant products includes agrochemical measures based on changes in the soil properties after the application of ameliorants. The dynamic models for studying the effect of the application of potassium fertilizers and dolomite powder on 137 Cs accumulation in plants are presented. Conceptual approaches to the development of models are based on the identification of mechanisms governing a complex of physico-chemical processes in soil after the use of ameliorants. The following assumptions were used in the development of models: - dynamics of 137 Cs distribution in each soil layer depends on the sorption processes characterized by different time to achieve quasi-equilibrium (exchangeable uptake and fixation by clay minerals) as well as on vertical migration process; - change in 137 Cs content in soil solution results from the radionuclide sorption on selective and nonselective exchange sites; - uptake of extra amounts of K + and Ca 2+ in soil solution produces effect on processes of 137 Cs exchangeable sorption and initiate specific processes responsible for 137 Cs fixation in the crystal lattice of clay minerals; - Ca 2+ and K + cations have a competing effect on 137 Cs uptake by plants from soil solution, which along with the fixation processes, causes lower accumulation of this radionuclide by plants during the application of ameliorants. The developed models were parameterized for soils of the coniferous forest located in the Bryansk region in area suffered from the radioactive fallout after the Chernobyl accident. Effects of ameliorants and time of their application on 137 Cs behaviour in the soil-plant system are assessed. The contribution of soil chemical and biological processes to the decrease in the radionuclide uptake by plants is estimated. (author)

  16. Frequency-difference MIT imaging of cerebral haemorrhage with a hemispherical coil array: numerical modelling.

    Science.gov (United States)

    Zolgharni, M; Griffiths, H; Ledger, P D

    2010-08-01

    The feasibility of detecting a cerebral haemorrhage with a hemispherical MIT coil array consisting of 56 exciter/sensor coils of 10 mm radius and operating at 1 and 10 MHz was investigated. A finite difference method combined with an anatomically realistic head model comprising 12 tissue types was used to simulate the strokes. Frequency-difference images were reconstructed from the modelled data with different levels of the added phase noise and two types of a priori boundary errors: a displacement of the head and a size scaling error. The results revealed that a noise level of 3 m degrees (standard deviation) was adequate for obtaining good visualization of a peripheral stroke (volume approximately 49 ml). The simulations further showed that the displacement error had to be within 3-4 mm and the scaling error within 3-4% so as not to cause unacceptably large artefacts on the images.

  17. Adsorption of zinc ions on bone char using helical coil-packed bed columns and its mass transfer modeling

    DEFF Research Database (Denmark)

    Moreno-Pérez, J.; Bonilla-Petriciolet, A.; Rojas-Mayorga, C. K.

    2016-01-01

    This study reports the assessment of helical coil-packed bed columns for Zn2+ adsorption on bone char. Zn2+ adsorption breakthrough curves have been obtained using helical coil columns with different characteristics and a comparison has been conducted with respect to the results of straight fixed-bed...... columns. Results showed that the helical coil adsorption columns may offer an equivalent removal performance than that obtained for the traditional packed bed columns but using a compact structure. However, the coil diameter, number of turns, and feed flow appear to be crucial parameters for obtaining...... the best performance in this packed-bed geometry. A mass transfer model for a mobile fluid flowing through a porous media was used for fitting and predicting the Zn2+ breakthrough curves in helical coil bed columns. Results of adsorbent physicochemical characterization showed that Zn2+ adsorption on bone...

  18. NCSX Trim Coil Design

    International Nuclear Information System (INIS)

    Kalish, M.; Brooks, A.; Rushinski, J.; Upcavage, R.

    2009-01-01

    The National Compact Stellarator Experiment (NCSX) was being constructed at the Princeton Plasma Physics Laboratory in partnership with Oak Ridge National Laboratory before work was stopped in 2008. The objective of this experiment was to develop the stellarator concept and evaluate it's potential as a model for future fusion power plants. Stellarator design requires very precisely positioned Modular Coils of complex shape to form 3D plasmas. In the design of NCSX, Trim Coils were required to compensate for both the positioning of the coils during assembly and the fabrication tolerances of the Modular Coils. Use of the Trim Coils allowed for larger tolerances increasing ease of assembly and decreasing overall cost. A set of Trim coils was developed to suppress the toroidal flux in island regions due to misalignment, magnetic materials, and eddy currents. The requirement imposed upon the design forced the toroidal flux in island regions below 10% of the total toroidal flux in the plasma. An analysis was first performed to evaluate candidate Trim Coil configurations iterating both the size, number, and position of the coils. The design was optimized considering both performance and cost while staying within the tight restraints presented by the space limited geometry. The final design of the Trim Coils incorporated a 48 Coil top bottom symmetric set. Fabrication costs were minimized by having only two coil types and using a planar conventional design with off the shelf commercial conductor. The Trim Coil design incorporated supports made from simple structural shapes assembled together in a way which allowed for adjustment as well as accommodation for the tolerance build up on the mating surfaces. This paper will summarize the analysis that led to the optimization of the Trim Coils set, the trim coil mechanical design, thermal and stress analysis, and the design of the supporting Trim Coil structure

  19. Fault Analysis of ITER Coil Power Supply System

    International Nuclear Information System (INIS)

    Song, In Ho; Jun, Tao; Benfatto, Ivone

    2009-01-01

    The ITER magnet coils are all designed using superconductors with high current carrying capability. The Toroidal Field (TF) coils operate in a steadystate mode with a current of 68 kA and discharge the stored energy in case of quench with using 9 interleaved Fast Discharge Units (FDUs). The Central Solenoid (CS) coils and Poloidal Field (PF) coils operate in a pulse mode with currents of up to 45 kA and require fast variation of currents inducing more than 10 kV during normal operation on the coil terminals using Switching Network (SN) systems (CSs, PF1 and 6) and Booster and VS converters (PF2 to 5), which are series connected to Main converters. SN and FDU systems comprise high current DC circuit breakers and resistors for generating high voltage (SN) and to dissipate magnetic energy (FDUs). High transient voltages can arise due to the switching operation of SN and FD and the characteristics of resistors and stray components of DC distribution systems. Also, faults in power supply control such as shorts or grounding faults can produce higher voltages between terminals and between terminal and ground. Therefore, the design of the coil insulation, coil terminal regions, feeders, feed throughs, pipe breaks and instrumentation must take account of these high voltages during normal and abnormal conditions. Voltage insulation level can be defined and it is necessary to test the coils at higher voltages, to be sure of reliable performance during the lifetime of operation. This paper describes the fault analysis of the TF, CS and PF coil power supply systems, taking account of the stray parameter of the power supply and switching systems and inductively coupled superconducting coil models. Resistor grounding systems are included in the simulation model and all fault conditions such as converter hardware and software faults, switching system hardware and software faults, DC short circuits and single grounding faults are simulated. The occurrence of two successive faults

  20. Transcranial Magnetic Stimulation: An Automated Procedure to Obtain Coil-specific Models for Field Calculations

    DEFF Research Database (Denmark)

    Madsen, Kristoffer Hougaard; Ewald, Lars; Siebner, Hartwig R.

    2015-01-01

    Background: Field calculations for transcranial magnetic stimulation (TMS) are increasingly implemented online in neuronavigation systems and in more realistic offline approaches based on finite-element methods. They are often based on simplified and/or non-validated models of the magnetic vector...... potential of the TMS coils. Objective: To develop an approach to reconstruct the magnetic vector potential based on automated measurements. Methods: We implemented a setup that simultaneously measures the three components of the magnetic field with high spatial resolution. This is complemented by a novel...... approach to determine the magnetic vector potential via volume integration of the measured field. Results: The integration approach reproduces the vector potential with very good accuracy. The vector potential distribution of a standard figure-of-eight shaped coil determined with our setup corresponds well...

  1. Thermal-hydraulic analysis of LTS cables for the DEMO TF coil using simplified models

    Directory of Open Access Journals (Sweden)

    Lewandowska Monika

    2017-03-01

    Full Text Available The conceptual design activities for the DEMOnstration reactor (DEMO – the prototype fusion power plant – are conducted in Europe by the EUROfusion Consortium. In 2015, three design concepts of the DEMO toroidal field (TF coil were proposed by Swiss Plasma Center (EPFL-SPC, PSI Villigen, Italian National Agency for New Technologies (ENEA Frascati, and Atomic Energy and Alternative Energies Commission (CEA Cadarache. The proposed conductor designs were subjected to complete mechanical, electromagnetic, and thermal-hydraulic analyses. The present study is focused on the thermal-hydraulic analysis of the candidate conductor designs using simplified models. It includes (a hydraulic analysis, (b heat removal analysis, and (c assessment of the maximum temperature and the maximum pressure in each conductor during quench. The performed analysis, aimed at verification whether the proposed design concepts fulfil the established acceptance criteria, provides the information for further improvements of the coil and conductors design.

  2. Conductor fabrication for ITER Model Coils. Status of the EU cabling and jacketing activities

    International Nuclear Information System (INIS)

    Corte, A. della; Ricci, M.V.; Spadoni, M.; Bessette, D.; Duchateau, J.L.; Salpietro, E.; Garre, R.; Rossi, S.; Penco, R.; Laurenti, A.

    1994-01-01

    The conductors for the ITER magnets are being defined according to the operating requirements of the machine. To demonstrate the technological feasibility of the main features of the magnets, two model coils (central solenoid and toroidal field), with bores in the range 2-3 m, will be manufactured. This is the first significant industrial production of full-size conductor (a total of about 6.5 km for these coils). One cabling and one jacketing line have been assembled in Europe. The former can cable up to 1100 m (6 tons) unit lengths; the latter, which can also handle 1000 m conductor lengths, has been assembled in a shorter version (320 m). A description of the lines is reported, together with the results of the trials performed up to now. (author) 2 figs

  3. Testing of ITER central solenoid coil insulation in an array

    International Nuclear Information System (INIS)

    Jayakumar, R.; Martovetsky, N.N.; Perfect, S.A.

    1995-01-01

    A glass-polyimide insulation system has been proposed by the US team for use in the Central Solenoid (CS) coil of the international Thermonuclear Experimental Reactor (ITER) machine and it is planned to use this system in the CS model coil inner module. The turn insulation will consist of 2 layers of combined prepreg and Kapton. Each layer is 50% overlapped with a butt wrap of prepreg and an overwrap of S glass. The coil layers will be separated by a glass-resin composite and impregnated in a VPI process. Small scale tests on the various components of the insulation are complete. It is planned to fabricate and test the insulation in a 4 x 4 insulated CS conductor array which will include the layer insulation and be vacuum impregnated. The conductor array will be subjected to 20 thermal cycles and 100000 mechanical load cycles in a Liquid Nitrogen environment. These loads are similar to those seen in the CS coil design. The insulation will be electrically tested at several stages during mechanical testing. This paper will describe the array configuration, fabrication: process, instrumentation, testing configuration, and supporting analyses used in selecting the array and test configurations

  4. Modelling of 137Cs behaviour in forest ecosystems and prediction of its accumulation in forest products

    International Nuclear Information System (INIS)

    Spiridonov, S.I.; Fesenko, S.V.; Gontarenko, I.A.; Avila, R.

    2001-01-01

    A mathematical model of 137 Cs migration in forest ecosystem contaminated due to the Chernobyl accident presented, which describes the behaviour of this radionuclide in the forest litter-soil system, tress, and forest animals. The model's parameters for different types of forest ecosystems are estimated and model's adequacy is tested through the use of independent experimental data. The sensitivity of the model's output variables is analyzed to variations in the most significant parameters. The differences in the seasonal and mean annual dynamics of 137 Cs concentration in muscles of roe deers and mooses are shown to be defined by specific features of the diets of these animals and variations in 137 Cs content in the main diet components [ru

  5. An Experimental Investigation of FNN Model for Wind Speed Forecasting Using EEMD and CS

    Directory of Open Access Journals (Sweden)

    Jianzhou Wang

    2015-01-01

    Full Text Available With depletion of traditional energy and increasing environmental problems, wind energy, as an alternative renewable energy, has drawn more and more attention internationally. Meanwhile, wind is plentiful, clean, and environmentally friendly; moreover, its speed is a very important piece of information needed in the operations and planning of the wind power system. Therefore, choosing an effective forecasting model with good performance plays a quite significant role in wind power system. A hybrid CS-EEMD-FNN model is firstly proposed in this paper for multistep ahead prediction of wind speed, in which EEMD is employed as a data-cleaning method that aims to remove the high frequency noise embedded in the wind speed series. CS optimization algorithm is used to select the best parameters in the FNN model. In order to evaluate the effectiveness and performance of the proposed hybrid model, three other short-term wind speed forecasting models, namely, FNN model, EEMD-FNN model, and CS-FNN model, are carried out to forecast wind speed using data measured at a typical site in Shandong wind farm, China, over three seasons in 2011. Experimental results demonstrate that the developed hybrid CS-EEMD-FNN model outperforms other models with more accuracy, which is suitable to wind speed forecasting in this area.

  6. Model of vortex dynamics in superconducting films in two-coil measurements of the coherence length

    Science.gov (United States)

    Lemberger, Thomas; Loh, Yen Lee

    In two-coil measurements on superconducting films, a magnetic field from a small coil is applied to the center of the film. When the amplitude of the ac field is increased, the film undergoes a transition from the ``Meissner'' state to a state with vortices and antivortices. Ultimately, the vortex density matches the applied magnetic field and field screening is negligible. Experimentally, the field at the transition is related to the superconducting coherence length, although a full theory of the relationship is lacking. We show that the mutual inductance between drive and pickup coils, on opposite sides of the film, as a function of ac field amplitude is well-described by a phenomenological model in which vortices and antivortices appear together in the film at the radius where the induced supercurrent is strongest, and then they move through a landscape of moderately strong vortex pinning sites. Work at OSU supported by DOE-Basic Energy Sciences through Grant No. FG02-08ER46533.

  7. A Non-Linear Finite Element Model for the LHC Main Dipole Coil Cross-Section

    CERN Document Server

    Pojer, M; Scandale, Walter

    2006-01-01

    The production of the dipole magnets for the Large Hadron Collider is at its final stage. Nevertheless, some mechanical instabilities are still observed for which no clear explanation has been found yet. A FE modelization of the dipole cold mass cross-section had already been developed at CERN, mainly for magnetic analysis, taking into account conductor blocks and a frictionless behavior. This paper describes a new ANSYS® model of the dipole coil cross-section, featuring individual turns inside conductor blocks, and implementing friction and the mechanical non-linear behavior of insulated cables. Preliminary results, comparison with measurements performed in industry and ongoing developments are discussed.

  8. Design and Fabrication of the KSTAR Poloidal Field Coil Structure

    International Nuclear Information System (INIS)

    Park, H. K.; Choi, C. H.; Sa, J. W.

    2005-01-01

    The KSTAR magnet system consists of 16 toroidal field(TF) coils. 4 pairs of central solenoid(CS) coils, and 3 pairs of outer poloidal field(PF) coils. The TF coils are encased in a structure to enhance mechanical stability. The CS coil structure is supported on top of the TF coil structure and supplies a vertical compression of 15 MN to prevent lateral movement due to a repulsive force between the CS coils. The PF coil system is vertically symmetry to the machine mid-plane and consists of 6 coils and 80 support structures(i.e, 16 for PF5, 32 for PF6 and 32 fort PF7). All PF coil structures should absorb the thermal contraction difference between TF coil structure and PF coils due to cool down and endure the vertical and radial magnetic forces due to current charging. In order to satisfy these structural requirements. the PF5 coil structure is designed base on hinges and both of PF6 and PF7 coil structures based on flexible plates. The PF coil structures are assembled on the TF coil structure with an individual basement that is welded on the TF coil structure

  9. Stochastic Modeling and Performance Analysis of Multimedia SoCs

    DEFF Research Database (Denmark)

    Raman, Balaji; Nouri, Ayoub; Gangadharan, Deepak

    2013-01-01

    solutions where each modeling technique has both the above mentioned characteristics. We present a probabilistic analytical framework and a statistical model checking approach to design system-on-chips for low-cost multimedia systems. We apply the modeling techniques to size the output buffer in a video......Reliability and flexibility are among the key required features of a framework used to model a system. Existing approaches to design resource-constrained, soft-real time systems either provide guarantees for output quality or account for loss in the system, but not both. We propose two independent...... decoder. The results shows that, for our stochastic design metric, the analytical framework upper bounds (and relatively accurate) compare to the statistical model checking technique. Also, we observed significant reduction in resource usage (such as output buffer size) with tolerable loss in output...

  10. A theoretical study of CsI:Tl columnar scintillator image quality parameters by analytical modeling

    Energy Technology Data Exchange (ETDEWEB)

    Kalyvas, N., E-mail: nkalyvas@teiath.gr; Valais, I.; Michail, C.; Fountos, G.; Kandarakis, I.; Cavouras, D.

    2015-04-11

    Medical X-ray digital imaging systems such as mammography, radiography and computed tomography (CT), are composed from efficient radiation detectors, which can transform the X-rays to electron signal. Scintillators are materials that emit light when excited by X-rays and incorporated in X-ray medical imaging detectors. Columnar scintillator, like CsI:T1 is very often used for X-ray detection due to its higher performance. The columnar form limits the lateral spread of the optical photons to the scintillator output, thus it demonstrates superior spatial resolution compared to granular scintillators. The aim of this work is to provide an analytical model for calculating the MTF, the DQE and the emission efficiency of a columnar scintillator. The model parameters were validated against published Monte Carlo data. The model was able to predict the overall performance of CsI:Tl scintillators and suggested an optimum thickness of 300 μm for radiography applications. - Highlights: • An analytical model for calculating MTF, DQE and Detector Optical Gain (DOG) of columnar phosphors was developed. • The model was fitted to published efficiency and MTF Monte Carlo data. • A good fit was observed for 300 µm columnar CsI:Tl thickness. • The performance of the 300 µm column thickness CsI:Tl was better in terms of MTF and DOG for radiographic applications.

  11. A Nonlinear Model of Mix Coil Spring – Rubber for Vertical Suspension of Railway Vehicle

    Directory of Open Access Journals (Sweden)

    Dumitriu Mădălina

    2016-03-01

    Full Text Available The paper focuses on a nonlinear model to represent the mechanical behaviour of a mix coil spring - rubber used in the secondary suspension of passenger rail vehicles. The principle of the model relies on overlapping of the forces corresponding to three components - the elastic component, the viscous component and the dry friction component. The model has two sources on non-linearity, in the elastic force and the friction force, respectively. The main attributes of the model are made visible by its response to an imposed displacement-type harmonic excitation. The results thus obtained from the applications of numerical simulation show a series of basic properties of the model, namely the dependence on amplitude and the excitation frequency of the model response, as well as of its stiffness and damping.

  12. Nonlinear instabilities induced by the F coil power amplifier at FTU: Modeling and control

    International Nuclear Information System (INIS)

    Zaccarian, L.; Boncagni, L.; Cascone, D.; Centioli, C.; Cerino, S.; Gravanti, F.; Iannone, F.; Mecocci, F.; Pangione, L.; Podda, S.; Vitale, V.; Vitelli, R.

    2009-01-01

    In this paper we focus on the instabilities caused by the nonlinear behavior of the F coil current amplifier at FTU. This behavior induces closed-loop instability of the horizontal position stabilizing loop whenever the requested current is below the circulating current level. In the paper we first illustrate a modeling phase where nonlinear dynamics are derived and identified to reproduce the open-loop responses measured by the F coil current amplifier. The derived model is shown to successfully reproduce the experimental behavior by direct comparison with experimental data. Based on this dynamic model, we then reproduce the closed-loop scenario of the experiment and show that the proposed nonlinear model successfully reproduces the nonlinear instabilities experienced in the experimental sessions. Given the simulation setup, we next propose a nonlinear control solution to this instability problem. The proposed solution is shown to recover stability in closed-loop simulations. Experimental tests are scheduled for the next experimental campaign after the FTU restart.

  13. Fault diagnosis and comparing risk for the steel coil manufacturing process using statistical models for binary data

    International Nuclear Information System (INIS)

    Debón, A.; Carlos Garcia-Díaz, J.

    2012-01-01

    Advanced statistical models can help industry to design more economical and rational investment plans. Fault detection and diagnosis is an important problem in continuous hot dip galvanizing. Increasingly stringent quality requirements in the automotive industry also require ongoing efforts in process control to make processes more robust. Robust methods for estimating the quality of galvanized steel coils are an important tool for the comprehensive monitoring of the performance of the manufacturing process. This study applies different statistical regression models: generalized linear models, generalized additive models and classification trees to estimate the quality of galvanized steel coils on the basis of short time histories. The data, consisting of 48 galvanized steel coils, was divided into sets of conforming and nonconforming coils. Five variables were selected for monitoring the process: steel strip velocity and four bath temperatures. The present paper reports a comparative evaluation of statistical models for binary data using Receiver Operating Characteristic (ROC) curves. A ROC curve is a graph or a technique for visualizing, organizing and selecting classifiers based on their performance. The purpose of this paper is to examine their use in research to obtain the best model to predict defective steel coil probability. In relation to the work of other authors who only propose goodness of fit statistics, we should highlight one distinctive feature of the methodology presented here, which is the possibility of comparing the different models with ROC graphs which are based on model classification performance. Finally, the results are validated by bootstrap procedures.

  14. Modelling of 137Cs concentration change in organisms of the Japanese coastal food chains

    International Nuclear Information System (INIS)

    Tateda, Y.; Nakahara, M.; Nakamura, R.

    1999-01-01

    In order to predict 137 CS concentrations in marine organisms of Japanese coastal food chains, a basic compartment model being composed of nuclide transfer both from seawater and food chain was investigated. Food chain structure of typical Japanese coastal water is established to include detritus, food chain, benthic food chain and planktonic food chain

  15. A simplified model of a mechanical cooling tower with both a fill pack and a coil

    Science.gov (United States)

    Van Riet, Freek; Steenackers, Gunther; Verhaert, Ivan

    2017-11-01

    Cooling accounts for a large amount of the global primary energy consumption in buildings and industrial processes. A substantial part of this cooling demand is produced by mechanical cooling towers. Simulations benefit the sizing and integration of cooling towers in overall cooling networks. However, for these simulations fast-to-calculate and easy-to-parametrize models are required. In this paper, a new model is developed for a mechanical draught cooling tower with both a cooling coil and a fill pack. The model needs manufacturers' performance data at only three operational states (at varying air and water flow rates) to be parametrized. The model predicts the cooled, outgoing water temperature. These predictions were compared with experimental data for a wide range of operational states. The model was able to predict the temperature with a maximum absolute error of 0.59°C. The relative error of cooling capacity was mostly between ±5%.

  16. The generalized model of polypeptide chain describing the helix-coil transition in biopolymers

    International Nuclear Information System (INIS)

    Mamasakhlisov, E.S.; Badasyan, A.V.; Tsarukyan, A.V.; Grigoryan, A.V.; Morozov, V.F.

    2005-07-01

    In this paper we summarize some results of our theoretical investigations of helix-coil transition both in single-strand (polypeptides) and two-strand (polynucleotides) macromolecules. The Hamiltonian of the Generalized Model of Polypeptide Chain (GMPC) is introduced to describe the system in which the conformations are correlated over some dimensional range Δ (it equals 3 for polypeptide, because one H-bond fixes three pairs of rotation, for double strand DNA it equals to one chain rigidity because of impossibility of loop formation on the scale less than Δ). The Hamiltonian does not contain any parameter designed especially for helix-coil transition and uses pure molecular microscopic parameters (the energy of hydrogen bond formation, reduced partition function of repeated unit, the number of repeated units fixed by one hydrogen bond, the energies of interaction between the repeated units and the solvent molecules). To calculate averages we evaluate the partition function using the transfer-matrix approach. The GMPC allowed to describe the influence of a number of factors, affecting the transition, basing on a unified microscopic approach. Thus we obtained, that solvents change transition temperature and interval in different ways, depending on type of solvent and on energy of solvent- macromolecule interaction; stacking on the background of H-bonding increases stability and decreases cooperativity of melting. For heterogeneous DNA we could analytically derive well known formulae for transition temperature and interval. In the framework of GMPC we calculate and show the difference of two order parameters of helix-coil transition - the helicity degree, and the average fraction of repeated units in helical conformation. Given article has the aim to review the results obtained during twenty years in the context of GMPC. (author)

  17. Liquid rope coiling

    NARCIS (Netherlands)

    Ribe, N.M.; Habibi, M.; Bonn, D.

    2012-01-01

    A thin stream or rope of viscous fluid falling from a sufficient height onto a surface forms a steadily rotating helical coil. Tabletop laboratory experiments in combination with a numerical model for slender liquid ropes reveal that finite-amplitude coiling can occur in four distinct regimes

  18. Modelling and Practical Implementation of 2-Coil Wireless Power Transfer Systems

    Directory of Open Access Journals (Sweden)

    Hong Zhou

    2014-01-01

    Full Text Available Wireless power transfer (WPT based on inductive coupling could be potentially applied in many practical applications. It has attracted a lot of research interests in the last few years. In this paper, the modelling, design, and implementation of a 2-coil WPT system are represented. The prototype system can be implemented using conventional power electronic devices such as MOSFETs with very low costs as it works in relative low frequency range (less than 1 MHz. In order to find out about the optimal working area for the WPT system, the circuit model based on the practical parameters from the prototype is built. The relationships between the exciting frequency, coupling, and output power are analyzed based on the circuit and magnetic principles. Apart from the theoretic study, the detailed implementation of the WPT prototype including the coil design, digital frequency generation, and high frequency power electronics is also introduced in this paper. Experiments are conducted to verify the effectiveness of the circuit analysis. By carefully tuning the circuit parameters, the prototype is able to deliver 20 W power through 2.2 meter distance with 20–30% efficiency.

  19. Engineering design framework for a shape memory alloy coil spring actuator using a static two-state model

    International Nuclear Information System (INIS)

    An, Sung-Min; Cho, Kyu-Jin; Ryu, Junghyun; Cho, Maenghyo

    2012-01-01

    A shape memory alloy (SMA) coil spring actuator is fabricated by annealing an SMA wire wound on a rod. Four design parameters are required for the winding: the wire diameter, the rod diameter, the pitch angle and the number of active coils. These parameters determine the force and stroke produced by the actuator. In this paper, we present an engineering design framework to select these parameters on the basis of the desired force and stoke. The behavior of the SMA coil spring actuator is described in detail to provide information about the inner workings of the actuator and to aid in selecting the design parameters. A new static two-state model, which represents a force–deflection relation of the actuator at the fully martensitic state (M 100% ) and fully austenitic state (A 100% ), is derived for use in the design. Two nonlinear effects are considered in the model: the nonlinear detwinning effect of the SMA and the nonlinear geometric effect of the coil spring for large deformations. The design process is organized into six steps and is presented with a flowchart and design equations. By following this systematic approach, an SMA coil spring actuator can be designed for various applications. Experimental results verified the static two-state model for the SMA coil spring actuator and a case study showed that an actuator designed using this framework met the design requirements. The proposed design framework was developed to assist application engineers such as robotics researchers in designing SMA coil spring actuators without the need for full thermomechanical models. (paper)

  20. Results of 3-dimensional structural FE-modeling of the coil end-regions of the LHC main dipoles

    CERN Document Server

    Hoeck, U; Schillo, M; Perini, D; Siegel, N

    2000-01-01

    The transition region between the straight part and the ends of the coils of the LHC model and prototype dipole magnets are often identified as the origin of training quenches. In order to study how the discontinuities in the material properties of these regions affect coil pre-stress and possibly gain more insight in the quench behavior, a program was set up at CERN to analyze by 3D-FEM these particular regions. The ACCEL team, who performed a similar analysis for the main quadrupoles of the Superconducting Supercollider SSC, is entrusted with this program. In this paper we report on the results of 3D-modeling and analysis of the coil return end region, including the complete coil mass, of a 1-m single bore model magnet. This magnet represents all relevant features of the "two-in-one" LHC main dipole design concerning the winding configuration, the collar pack, the yoke, and the outer shell representing the He-vessel. The transition region between coil ends and straight section is modeled by slicing the magn...

  1. The 137Cs distribution in sediment profiles from the Yangtze River estuary: a comparison of modeling and experimental results

    International Nuclear Information System (INIS)

    Pan, S.M.; Xu, Y.H.; Wang, A.; Povinec, P.P.

    2012-01-01

    It has been generally accepted when estimating sedimentation rates using the 137 Cs dating method that the position of the 137 Cs maximum in a sediment profile represents the year 1963. In this paper we validated this approach by developing a model in which the annual 137 Cs global fallout flux for the Yangtze River estuary was established on the basis of the Tokyo flux corrected for precipitation rates observed in Shanghai. As the 137 Cs maxima in the sediment deposition profiles depend on the sedimentation rates, the sub-sampling intervals were calculated accordingly. Higher measured than the calculated values were found in some cores, what may be due to fluctuating sedimentation rates and an additional deposition of 137 Cs from land-based sources. The study provides useful information on the reliability of the measured 137 Cs maxima in sediment profiles frequently used for dating of sediments in marine (coastal regions, open seas) as well as in terrestrial (lakes) environments. (author)

  2. Empirical component model to predict the overall performance of heating coils: Calibrations and tests based on manufacturer catalogue data

    International Nuclear Information System (INIS)

    Ruivo, Celestino R.; Angrisani, Giovanni

    2015-01-01

    Highlights: • An empirical model for predicting the performance of heating coils is presented. • Low and high heating capacity cases are used for calibration. • Versions based on several effectiveness correlations are tested. • Catalogue data are considered in approach testing. • The approach is a suitable component model to be used in dynamic simulation tools. - Abstract: A simplified methodology for predicting the overall behaviour of heating coils is presented in this paper. The coil performance is predicted by the ε-NTU method. Usually manufacturers do not provide information about the overall thermal resistance or the geometric details that are required either for the device selection or to apply known empirical correlations for the estimation of the involved thermal resistances. In the present work, heating capacity tables from the manufacturer catalogue are used to calibrate simplified approaches based on the classical theory of heat exchangers, namely the effectiveness method. Only two reference operating cases are required to calibrate each approach. The validity of the simplified approaches is investigated for a relatively high number of operating cases, listed in the technical catalogue of a manufacturer. Four types of coils of three sizes of air handling units are considered. A comparison is conducted between the heating coil capacities provided by the methodology and the values given by the manufacturer catalogue. The results show that several of the proposed approaches are suitable component models to be integrated in dynamic simulation tools of air conditioning systems such as TRNSYS or EnergyPlus

  3. Cleanup techniques for Finnish urban environments and external doses from 137Cs - modelling and calculations

    International Nuclear Information System (INIS)

    Moring, M.; Markkula, M.L.

    1997-03-01

    The external doses under various radioactive deposition conditions are assessed and the efficiencies of some simple decontamination techniques (grass cutting, vacuum sweeping, hosing of paved surfaces and roofs, and felling trees) are compared in the study. The present model has been constructed for the Finnish conditions and housing areas, using 137 Cs transfer data from the Nordic and Central European studies and models. The compartment model concerns behaviour and decontamination of 137 Cs in the urban environment under summer conditions. Doses to man have been calculated for wet (light rain) and dry deposition in four typical Finnish building areas: single-family wooden houses, brick terraced-houses, blocks of flats and urban office buildings. (26 refs.)

  4. Yang-Lee zeros for a Potts model of helix-coil transition with nontrivial topology

    International Nuclear Information System (INIS)

    Ananikian, N.; Ananikyan, L.; Artuso, R.; Sargsyan, K.

    2007-07-01

    The Yang-Lee partition function zeros of the Q-state Potts model on a zigzag ladder are studied by a transfer-matrix approach. This Q-state model has a non-trivial topology induced by three-site interactions on a zigzag ladder and is proposed as a description of helix-coil transition in homo-polymers. The Yang-Lee zeros are associated to complex values of the solvent-related coupling constant K (magnetic field) and they are exactly derived for arbitrary values of the system parameters: Q, J (coupling constant of hydrogen binding) and temperature. It is shown that there is only a quasi-phase transition for all temperatures. The densities of the Yang-Lee zeros are singular at the edge singularity points and the critical exponent σ = -1/2. (author)

  5. Crystal field effect in the uranium compounds - model calculations for CsUF/sub 6/, Cs/sub 2/UCl/sub 6/ and UCl/sub 4/

    Energy Technology Data Exchange (ETDEWEB)

    Gajek, Z.; Mulak, J.; Faucher, M.

    1987-01-01

    A practical crystal field model allowing one to estimate the crystal field parameters from first principles is presented and applied to the actinide compounds. The model results directly from the renormalization (and reduction) procedure of the true Schroedinger equation for an effective Hamiltonian acting on the 5f spin-orbitals only. In practice this approach becomes convergent with the ab initio model of Newman. Three ionic uranium compounds: CsUF/sub 6/, Cs/sub 2/UCl/sub 6/ and UCl/sub 4/ have served as examples of the application. The results obtained, particularly for the first two compounds, are in good agreement with the experimental data. The contributions of different mechanisms responsible for the crystal field effect are discussed.

  6. Crystal field effect in the uranium compounds - model calculations for CsUF6, Cs2UCl6 and UCl4

    International Nuclear Information System (INIS)

    Gajek, Z.; Mulak, J.

    1987-01-01

    A practical crystal field model allowing one to estimate the crystal field parameters from first principles is presented and applied to the actinide compounds. The model results directly from the renormalization (and reduction) procedure of the true Schroedinger equation for an effective Hamiltonian acting on the 5f spin-orbitals only. In practice this approach becomes convergent with the ab initio model of Newman. Three ionic uranium compounds: CsUF 6 , Cs 2 UCl 6 and UCl 4 have served as examples of the application. The results obtained, particularly for the first two compounds, are in good agreement with the experimental data. The contributions of different mechanisms responsible for the crystal field effect are discussed. (author)

  7. Modeling of leachable 137Cs in throughfall and stemflow for Japanese forest canopies after Fukushima Daiichi Nuclear Power Plant accident

    International Nuclear Information System (INIS)

    Loffredo, Nicolas; Onda, Yuichi; Kawamori, Ayumi; Kato, Hiroaki

    2014-01-01

    The Fukushima accident dispersed significant amounts of radioactive cesium (Cs) in the landscape. Our research investigated, from June 2011 to November 2013, the mobility of leachable Cs in forests canopies. In particular, 137 Cs and 134 Cs activity concentrations were measured in rainfall, throughfall, and stemflow in broad-leaf and cedar forests in an area located 40 km from the power plant. Leachable 137 Cs loss was modeled by a double exponential (DE) model. This model could not reproduce the variation in activity concentration observed. In order to refine the DE model, the main physical measurable parameters (rainfall intensity, wind velocity, and snowfall occurrence) were assessed, and rainfall was identified as the dominant factor controlling observed variation. A corrective factor was then developed to incorporate rainfall intensity in an improved DE model. With the original DE model, we estimated total 137 Cs loss by leaching from canopies to be 72 ± 4%, 67 ± 4%, and 48 ± 2% of the total plume deposition under mature cedar, young cedar, and broad-leaf forests, respectively. In contrast, with the improved DE model, the total 137 Cs loss by leaching was estimated to be 34 ± 2%, 34 ± 2%, and 16 ± 1% of the total plume deposition under mature cedar, young cedar, and broad-leaf forests, respectively. The improved DE model corresponds better to observed data in literature. Understanding 137 Cs and 134 Cs forest dynamics is important for forecasting future contamination of forest soils around the FDNPP. It also provides a basis for understanding forest transfers in future potential nuclear disasters. - Highlights: • A double exponential model was used to model leachable cesium loss from canopies. • The model could not reproduce variation observed. • Rainfall was identified as the dominant factor controlling the variation. • A rainfall parameter was used to develop an improved double exponential model. • The improved model gives a better estimation

  8. Modelling of flexi-coil springs with rubber-metal pads in a locomotive running gear

    OpenAIRE

    Michálek T.; Zelenka J.

    2015-01-01

    Nowadays, flexi-coil springs are commonly used in the secondary suspension stage of railway vehicles. Lateral stiffness of these springs is influenced by means of their design parameters (number of coils, height, mean diameter of coils, wire diameter etc.) and it is often suitable to modify this stiffness in such way, that the suspension shows various lateral stiffness in different directions (i.e., longitudinally vs. laterally in the vehicle-related coordinate system). Therefore, these sprin...

  9. Development of model for studies on momentum transfer in electrochemical cells with entry region coil as turbulence promoter

    Science.gov (United States)

    Penta Rao, Tamarba; Rajendra Prasad, P.

    2018-04-01

    Entry region swirl promoters gain importance in industry because of its effectiveness in augmentation of mass and heat transfer augmentation. Design of equipment needs momentum transfer data along with mass or heat transfer data. Hence an experimental investigation was carried out with coaxially placed entry region spiral coil as turbulence promoters on momentum transfer in forced convection flow of electrolyte in circular conduits. Aqueous solution of sodium hydroxide and 0.01 M equimolal Ferri-ferro cyanide system was chosen for the study. The study covered parameters like effect of pitch of the coil, effect of length of the coil, diameter of the coil, diameter of the coil wire, diameter of the annular rod. The promoter is measured by limiting current technique using diffusion controlled electrochemical reactions. The study comprises of evaluation of momentum transfer rates at the outer wall of the electrochemical cell. Pressure drop measurements were also made to obtain the energy consumption pattern. Within the range of variables covered. The results are correlated by the momentum transfer similarity function. Momentum transfer coefficients were evaluated from measured limiting currents. Effect of each parameter was studied in terms of friction factor. A model was developed for momentum transfer. The experimental data on momentum transfer was modeled in terms of momentum transfer function and Reynolds number, geometric parameters.

  10. Modelling the Long Term Leaching Behaviour of 137CS from Different Stabilized Waste Matrices

    International Nuclear Information System (INIS)

    El-Kamash, A.M.

    2013-01-01

    Leaching characteristics of ''1''3''7Cs from immobilized waste matrices in different cement-based grouts have been assessed to investigate the influence of the additives on the leaching behavior of the solid waste matrices. The International Atomic Energy's Agency (IAEA) standard leach method has been employed to study the leach pattern of 137 Cs radionuclide from the immobilized waste form. The examination of the leaching data revealed that clay additives reduces the leach rate for the studied radionuclide. The controlling leaching mechanism has been studied and the transport parameters were calculated for all studied waste matrices. Simplified analytical models have been derived to predict the Cumulative Leach Fraction (CLF) of radionuclides over the studied experimental period. These simplified research models could be used as a screening tool to assess the performance of the waste matrix under repository conditions. (author)

  11. Equivalent Coil Model for Computing Levitation Forces Between Permanent Magnets and High Temperatures Superconductors

    International Nuclear Information System (INIS)

    Cavia Santos, S.; Garcia-Tabares, L.

    1998-05-01

    A new simple theory has been developed for the study of levitation forces between a permanent magnet and a HTc superconductor. This theory is based on the assumption that both, the magnet and the superconductor, can be modelled by an equivalent coil placed on their surface. While the current flowing through the permanent magnet is constant, the equivalent current through the superconductor can be iether corresponding to screen the overall flux or a constant current corresponding to critical current density when the superconductor is saturated. A test facility has been designed and built for measuring levitation forces at variable approaching speeds. Comparison between theoretical and experimental measurements are presented in the report as well as a general description of the test facility. (Author)

  12. Comparison of shape memory polymer foam versus bare metal coil treatments in an in vivo porcine sidewall aneurysm model.

    Science.gov (United States)

    Horn, John; Hwang, Wonjun; Jessen, Staci L; Keller, Brandis K; Miller, Matthew W; Tuzun, Egemen; Hartman, Jonathan; Clubb, Fred J; Maitland, Duncan J

    2017-10-01

    The endovascular delivery of platinum alloy bare metal coils has been widely adapted to treat intracranial aneurysms. Despite the widespread clinical use of this technique, numerous suboptimal outcomes are possible. These may include chronic inflammation, low volume filling, coil compaction, and recanalization, all of which can lead to aneurysm recurrence, need for retreatment, and/or potential rupture. This study evaluates a treatment alternative in which polyurethane shape memory polymer (SMP) foam is used as an embolic aneurysm filler. The performance of this treatment method was compared to that of bare metal coils in a head-to-head in vivo study utilizing a porcine vein pouch aneurysm model. After 90 and 180 days post-treatment, gross and histological observations were used to assess aneurysm healing. At 90 days, the foam-treated aneurysms were at an advanced stage of healing compared to the coil-treated aneurysms and showed no signs of chronic inflammation. At 180 days, the foam-treated aneurysms exhibited an 89-93% reduction in cross-sectional area; whereas coiled aneurysms displayed an 18-34% area reduction. The superior healing in the foam-treated aneurysms at earlier stages suggests that SMP foam may be a viable alternative to current treatment methods. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1892-1905, 2017. © 2016 Wiley Periodicals, Inc.

  13. The Short Model Coil (SMC) dipole: an R&D program towards Nb$_{3}$Sn accelerator magnets

    CERN Document Server

    Bajko, M; Canfer, S; Ellwood, G; Feuvrier, J; Guinchard, M; Karppinen, M; Kokkinos, C; Manil, P; Milanese, A; Oberli, L; Perez, J-C; Regis, F; de Rijk, G

    2011-01-01

    The Short Model Coil (SMC) assembly has been designed, as test bench for short racetrack coils wound with Nb$_{3}$Sn cable. The mechanical structure comprises an iron yoke surrounded by a 20 mm thick aluminium alloy shell, and includes four loading pads that transmit the required pre-compression from the outer shell into the two coils. The outer shell is pre-tensioned with mechanical keys that are inserted with the help of pressurized bladders and two 30 mm diameter aluminium alloy rods provide the axial loading to the coil ends. The outer shell, the axial rods, and the coils are instrumented with strain gauges, which allow precise monitoring of the loading conditions during the assembly and at cryogenic temperature during the magnet test. Two SMC assemblies have been completed and cold tested in the frame of a European collaboration between CEA (FR), CERN and STFC (UK) and with the technical support from LBNL (US). This paper describes the main features of the SMC assembly, the experience from the dummy asse...

  14. The SMC (Short Model Coil) dipole: An R&D program for Nb$_{3}$Sn accelerator magnets

    CERN Document Server

    Perez, J C; Bordini, B; Canfer, S; Ellwood, G; Feuvrier, J; Guinchard, M; Karppinen, M; Kokkinos, C; Manil, P; Milanese, A; Oberli, L; Regis, F; de Rijk, G

    2012-01-01

    The Short Model Coil (SMC) assembly has been designed, as test bench for short racetrack coils wound with Nb$_{3}$Sn cable. The mechanical structure comprises an iron yoke surrounded by a 20 mm thick aluminium alloy shell, and includes four loading pads that transmit the required pre-compression from the outer shell into the two coils. The outer shell is pre-tensioned with mechanical keys that are inserted with the help of pressurized bladders and two 30 mm diameter aluminium alloy rods provide the axial loading to the coil ends. The outer shell, the axial rods, and the coils are instrumented with strain gauges, which allow precise monitoring of the loading conditions during the assembly and at cryogenic temperature during the magnet test. Two SMC assemblies have been completed and cold tested in the frame of a European collaboration between CEA (FR), CERN and STFC (UK) and with the technical support from LBNL (US). This paper describes the main features of the SMC assembly, the experience from the dummy ass...

  15. Using finite element modelling and experimental methods to investigate planar coil sensor topologies for inductive measurement of displacement

    Directory of Open Access Journals (Sweden)

    Gregory Moreton

    2018-04-01

    Full Text Available The usage of planar sensors is widespread due to their non-contact nature and small size profiles, however only a few basic design types are generally considered. In order to develop planar coil designs we have performed extensive finite element modelling (FEM and experimentation to understand the performance of different planar sensor topologies when used in inductive sensing. We have applied this approach to develop a novel displacement sensor. Models of different topologies with varying pitch values have been analysed using the ANSYS Maxwell FEM package, furthermore the models incorporated a movable soft magnetic amorphous ribbon element. The different models used in the FEM were then constructed and experimentally tested with topologies that included mesh, meander, square coil, and circular coil configurations. The sensors were used to detect the displacement of the amorphous ribbon. A LabView program controlled both the displacement stage and the impedance analyser, the latter capturing the varying inductance values with ribbon displacement. There was good correlation between the FEM models and the experimental data confirming that the methodology described here offers an effective way for developing planar coil based sensors with improved performance.

  16. Using finite element modelling and experimental methods to investigate planar coil sensor topologies for inductive measurement of displacement

    Science.gov (United States)

    Moreton, Gregory; Meydan, Turgut; Williams, Paul

    2018-04-01

    The usage of planar sensors is widespread due to their non-contact nature and small size profiles, however only a few basic design types are generally considered. In order to develop planar coil designs we have performed extensive finite element modelling (FEM) and experimentation to understand the performance of different planar sensor topologies when used in inductive sensing. We have applied this approach to develop a novel displacement sensor. Models of different topologies with varying pitch values have been analysed using the ANSYS Maxwell FEM package, furthermore the models incorporated a movable soft magnetic amorphous ribbon element. The different models used in the FEM were then constructed and experimentally tested with topologies that included mesh, meander, square coil, and circular coil configurations. The sensors were used to detect the displacement of the amorphous ribbon. A LabView program controlled both the displacement stage and the impedance analyser, the latter capturing the varying inductance values with ribbon displacement. There was good correlation between the FEM models and the experimental data confirming that the methodology described here offers an effective way for developing planar coil based sensors with improved performance.

  17. Dynamic model for the transfer of CS-137 through the soil-grass-lamb foodchain

    DEFF Research Database (Denmark)

    Nielsen, S.P.

    1994-01-01

    A dynamic radioecological model for the transfer of radiocaesium through the soil-grass-lamb foodchain was constructed on the basis of field data collected in 1990–1993 from the Nordic countries: Denmark, Faroe Islands, Finland, Iceland, Norway and Sweden. The model assumes an initial soil...... contamination of one kilobecquerel of 137Cs per square metre and simulates the transfer to grass through root uptake in addition to direct contamination from resuspended activity. The model covers two different soil types: clay-loam and organic, with significantly different transfers of radiocaesium to grass...

  18. Modeling of twisted and coiled polymer (TCP) muscle based on phenomenological approach

    Science.gov (United States)

    Karami, Farzad; Tadesse, Yonas

    2017-12-01

    Twisted and coiled polymers (TCP) muscles are linear actuators that respond to change in temperature. Exploiting high negative coefficient of thermal expansion (CTE) and helical geometry give them a significant ability to change length in a limited temperature range. Several applications and experimental data of these materials have been demonstrated in the last few years. To use these actuators in robotics and control system applications, a mathematical model for predicting their behavior is essential. In this work, a practical and accurate phenomenological model for estimating the displacement of TCP muscles, as a function of the load as well as input electrical current, is proposed. The problem is broken down into two parts, i.e. modeling of the electro-thermal and then the thermo-elastic behavior of the muscles. For the first part, a differential equation, with changing electrical resistance term, is derived. Next, by using a temperature-dependent modulus of elasticity and CTE as well as taking the geometry of the muscles into account, an expression for displacement is derived. Experimental data for different loads and actuation current levels are used for verifying the model and investigating its accuracy. The result shows a good agreement between the simulation and experimental results for all loads.

  19. Application of modeling methods for an estimation of a specific activity 137Cs geologic environment

    International Nuclear Information System (INIS)

    Kalinovskij, A.K.; Batij, V.G.; Pravdivyj, A.A.; Krasnov, V.A.

    2004-01-01

    The manual application of methods of mathematical and physical modeling for an estimation of the specific activity 137 Cs in soils composing a geological profile of site of object 'Ukryttya' is demonstrated. The calculations are executed by the software packages of Micro Shield, CYCLON, MCNP5. The experimental measurements are carried out by logging radiometers of different type on the borehole models. The value of a conversion coefficient of infinite environment for quantitative interpretation of gamma-ray logging data is determined over calculations outcomes and experimental measurements. The calculated and experimental values have agreement among themselves. the error estimation of the obtained outcomes is executed. 26 refs., 3 tab., 10 figs

  20. Modeling dynamics of {sup 137}Cs in forest surface environments: Application to a contaminated forest site near Fukushima and assessment of potential impacts of soil organic matter interactions

    Energy Technology Data Exchange (ETDEWEB)

    Ota, Masakazu, E-mail: ohta.masakazu@jaea.go.jp; Nagai, Haruyasu; Koarashi, Jun

    2016-05-01

    A process-based model for {sup 137}Cs transfer in forest surface environments was developed to assess the dynamic behavior of Fukushima-derived {sup 137}Cs in a Japanese forest. The model simulation successfully reproduced the observed data from 3 year migration of {sup 137}Cs in the organic and mineral soil layers at a contaminated forest near Fukushima. The migration of {sup 137}Cs from the organic layer to the mineral soil was explained by the direct deposition pattern on the forest floor and the turnover of litter materials in the organic layer under certain ecological conditions. Long-term predictions indicated that more than 90% of the deposited {sup 137}Cs would remain within the top 5 cm of the soil for up to 30 years after the accident, suggesting that the forest acts as an effective long-term reservoir of {sup 137}Cs with limited transfer via the groundwater pathway. The model was also used to explore the potential impacts of soil organic matter (SOM) interactions on the mobility and bioavailability of {sup 137}Cs in the soil–plant system. The simulation results for hypothetical organic soils with modified parameters of {sup 137}Cs turnover revealed that the SOM-induced reduction of {sup 137}Cs adsorption elevates the fraction of dissolved {sup 137}Cs in the soil solution, thereby increasing the soil-to-plant transfer of {sup 137}Cs without substantially altering the fractional distribution of {sup 137}Cs in the soil. Slower fixation of {sup 137}Cs on the flayed edge site of clay minerals and enhanced mobilization of the clay-fixed {sup 137}Cs in organic-rich soils also appeared to elevate the soil-to-plant transfer of {sup 137}Cs by increasing the fraction of the soil-adsorbed (exchangeable) {sup 137}Cs. A substantial proportion (approximate 30%–60%) of {sup 137}Cs in these organic-rich soils was transferred to layers deeper than 5 cm decades later. These results suggested that SOM influences the behavior of {sup 137}Cs in forests over a prolonged

  1. An improved FEM model for computing transport AC loss in coils made of RABiTS YBCO coated conductors for electric machines

    DEFF Research Database (Denmark)

    Ainslie, Mark D; Rodriguez Zermeno, Victor Manuel; Hong, Zhiyong

    2011-01-01

    and magnetic field-dependent critical current densities, and the inclusion and exclusion of a magnetic substrate, as found in RABiTS (rolling-assisted biaxially textured substrate) YBCO coated conductors. The coil model is based on the superconducting stator coils used in the University of Cambridge EPEC...

  2. Magnetic Design and Code Benchmarking of the SMC (Short Model Coil) Dipole Magnet

    CERN Document Server

    Manil, P; Rochford, J; Fessia, P; Canfer, S; Baynham, E; Nunio, F; de Rijk, G; Védrine, P

    2010-01-01

    The Short Model Coil (SMC) working group was set in February 2007 to complement the Next European Dipole (NED) program, in order to develop a short-scale model of a Nb$_{3}$Sn dipole magnet. In 2009, the EuCARD/HFM (High Field Magnets) program took over these programs. The SMC group comprises four laboratories: CERN/TE-MSC group (CH), CEA/IRFU (FR), RAL (UK) and LBNL (US). The SMC magnet is designed to reach a peak field of about 13 Tesla (T) on conductor, using a 2500 A/mm2 Powder-In-Tube (PIT) strand. The aim of this magnet device is to study the degradation of the magnetic properties of the Nb$_{3}$Sn cable, by applying different levels of pre-stress. To fully satisfy this purpose, a versatile and easy-to-assemble structure has been realized. The design of the SMC magnet has been developed from an existing dipole magnet, the SD01, designed, built and tested at LBNL with support from CEA. The goal of the magnetic design presented in this paper is to match the high field region with the high stress region, l...

  3. A comparison of three models of 137Cs transfer in forest ecosystems

    International Nuclear Information System (INIS)

    Avila, R.; Bergman, R.; Scimone, M.; Fesenko, S.; Sancharova, N.; Moberg, L.

    2001-01-01

    The predictions of three models of 137 Cs transfer in forest ecosystems (FOA, LOGNAT and FORESTLAND) were compared. The scenario for the model-model comparison consisted of an acute dry deposition of 137 Cs over a coniferous forest. The model predictions were subsequently compared (model-data comparison) with values derived from experimental data measured in forests of the Bryansk region in Russia that were contaminated by the Chernobyl accident and that have similar characteristics to the forests described in the scenario. The predictions of radiocaesium levels in the litter-soil layer, berries, needles, wood, whole tree and moose made with the models were in relatively good agreement with each other (within a factor of 1.4-2.9). The best agreement was observed for berries and moose and the worst for wood. There was also good agreement between the model predictions for the same variables and the experimental data (within a factor of 1.2-3.2). In this case, the best agreement was observed for the litter-soil layer and the worst for wood and the whole tree. Overall, at least for the studied scenario and for the first 10 years after deposition, any of the models can be used if the final aim is to estimate average concentrations in different forest components. The agreement between the model predictions worsens with time and there were differences in the form of the time dependencies predicted by the models, especially for wood. This may lead to larger differences between the model predictions and the experimental data for times beyond the period for which data were available for comparison (10 years after the deposition)

  4. An Evaluation of the Measurement Properties of the Five Cs Model of Positive Youth Development.

    Science.gov (United States)

    Conway, Ronan J; Heary, Caroline; Hogan, Michael J

    2015-01-01

    There is growing recognition of the need to develop acceptable measures of adolescent's positive attributes in diverse contexts. The current study evaluated the measurement properties of the Five Cs model of Positive Youth Development (PYD) scale (Lerner et al., 2005) using a sample of 672 Irish adolescents. Confirmatory factor analyses indicated that a five-factor model provided a good fit to the data. The internal reliability and construct validity of the Five Cs model were supported, with character the strongest predictor of contribution, while connection was the strongest predictor of risky-behaviors. Notably, confidence was significantly negatively related to contribution, and positively related to risky-behaviors. Multi-group hierarchical nested models supported measurement invariance across early- (11-14 years) and late- (15-19 years) adolescent age groups, with partial invariance found across gender. Younger adolescents evinced higher PYD, while PYD was associated with higher contribution and lower depression and risk-behaviors across all groups. The application of the PYD framework as a measure of positive functioning across adolescence is discussed.

  5. Use of Cs-137 for the calibration of the circulation model of Lithuanian coastal waters

    International Nuclear Information System (INIS)

    Davuliene, L.; Trinkunas, G.; Remeikis, V.; Valkunas, L.; Dick, S.

    2002-01-01

    It is well established that radioactive contamination of waters and sediments in the Lithuanian coastal area of the Baltic Sea is distributed unevenly. To describe the distribution of the radionuclides in waters of the Lithuanian coastal area of the Baltic Sea, the model based on the operational circulation model of the Bundesamt fuer Seeschffahrt und Hydrographie (BSH) for the North and Baltic seas was developed. The area under consideration contains both the Lithuanian coast of the Baltic Sea as well as the Curonian Gulf of the fresh water. The interplay between the salt and fresh water flows via the Kaipeda strait has impact on the distribution of radionuclides. For instance, Cs-137 is a typical radionuclide demonstrating this effect. It is experimentally well established that this radionuclide in the salt water is mainly in the dissolved form (about 90%) and just its minor part is concentrated in the suspended matter (about 10%). In fresh water the dissolved/suspended matter ratio for Cs-137 is totally opposite. Therefore, Cs-137 can be considered as the tracer following the fresh and salt water mixing. With samples of the radionuclide concentration in the sea area under consideration at hand, Cs-137 is used to normalize the tracer concentration simulated by the developed circulation model. The model was based on the grade of 1 nautic mile (nm), while the boundary conditions were taken from the more extended BSH model on the 6 nm grade. In order to understand the sensitivity of this local model to the initial conditions, the artificial conditions taken from the more general and coarse model were used. It has been obtained that the effect of the initial conditions is lost within 2-3 weeks. This result is independent of the coarse grain of the grade as calculations carried out on 1 nm and 0.5 nm grades show. The model was adopted for the PC Pentium III, and calculations of the salinity distribution depending on the meteorological conditions were carried out. Real

  6. An assessment of heat transfer models of water flow in helically coiled tubes based on selected experimental datasets

    International Nuclear Information System (INIS)

    Gou, Junli; Ma, Haifu; Yang, Zijiang; Shan, Jianqiang

    2017-01-01

    Highlights: •A review of heat transfer characteristics for water flow in helically coiled tubes are conducted. •An assessment of heat transfer models under different heat transfer modes in helically coiled tubes are performed. •This work could provide references for the use of the correlations and for further studies. -- Abstract: This paper presents an assessment of the heat transfer models under different heat transfer modes for water flow in helically coiled tubes based on the compiled datasets from the reviewed literatures. For single phase flow, most of the correlations of the heat transfer coefficient can fit well to the experiments. The correlations of Xin-Ebadian, Dravid and Kalb-Seader for laminar flow and those of Seban-McLaughlim, Mori-Nakayama, Xin-Ebadian, Hardik, Rogers-Mayhew, Mikaila-Poskas and El-Genk-Schriener for turbulent flow are recommended. For flow boiling heat transfer, Steiner-Taborek correlation could be utilized to predict the boiling heat transfer coefficients in helically coiled tubes for a relatively wide range of parameters. For dryout quality, the correlations of Hwang et al. and Santini et al. give relatively better predictions than others. However, more accurate correlations for flow boiling heat transfer coefficient and dryout quality need to be developed based on further investigations with wider parameter ranges in the future. The present work could provide references for the investigators for future uses of those correlations and for performing further investigations on the heat transfer characteristics of water flow in helically coiled tubes.

  7. Evaluation of sorption distribution coefficient of Cs onto granite using sorption data collected in sorption database and sorption model

    International Nuclear Information System (INIS)

    Nagasaki, S.

    2013-01-01

    Based on the sorption distribution coefficients (K d ) of Cs onto granite collected from the JAERI Sorption Database (SDB), the parameters for a two-site model without the triple-layer structure were optimized. Comparing the experimentally measured K d values of Cs onto Mizunami granite carried out by JAEA with the K d values predicted by the model, the effect of the ionic strength on the K d values of Cs onto granite was evaluated. It was found that K d values could be determined using the content of biotite in granite at a sodium concentration ([Na]) of 1 x 10 -2 to 5 x 10 -1 mol/dm 3 . It was suggested that in high ionic strength solutions, the sorption of Cs onto other minerals such as microcline should also be taken into account. (author)

  8. Evaluation of sorption distribution coefficient of Cs onto granite using sorption data collected in sorption database and sorption model

    Energy Technology Data Exchange (ETDEWEB)

    Nagasaki, S., E-mail: nagasas@mcmaster.ca [McMaster Univ., Hamilton, Ontario (Canada)

    2013-07-01

    Based on the sorption distribution coefficients (K{sub d}) of Cs onto granite collected from the JAERI Sorption Database (SDB), the parameters for a two-site model without the triple-layer structure were optimized. Comparing the experimentally measured K{sub d} values of Cs onto Mizunami granite carried out by JAEA with the K{sub d} values predicted by the model, the effect of the ionic strength on the K{sub d} values of Cs onto granite was evaluated. It was found that K{sub d} values could be determined using the content of biotite in granite at a sodium concentration ([Na]) of 1 x 10{sup -2} to 5 x 10{sup -1} mol/dm{sup 3} . It was suggested that in high ionic strength solutions, the sorption of Cs onto other minerals such as microcline should also be taken into account. (author)

  9. The use of Chernobyl data to test model predictions for interindividual variability of 137Cs concentrations in humans

    International Nuclear Information System (INIS)

    Hoffman, F. Owen; Thiessen, Kathleen M.

    1996-01-01

    Data sets assembled in the aftermath of the Chernobyl accident as a part of the International Atomic Energy Agency's model testing program (VAMP) have provided a rare opportunity for 'blind-testing' predictions made with exposure assessment models. Measurements of Chernobyl-derived 137 Cs in Central Bohemia (Czech Republic) and southern Finland were used to test model predictions for a number of endpoints, including the distribution of whole-body concentrations of 137 Cs in adults in these regions at specified time points. This test endpoint required separation of uncertainty due to stochastic variability (aleatoric uncertainty) and uncertainty due to lack of knowledge about fixed but unknown values (epistemic uncertainty). Predictions of the distribution of whole-body 137 Cs concentrations were made by a minority of the participants in these model-testing exercises. Major reasons for misprediction included bias in the bioavailability of 137 Cs in soil and misestimation of the total intake of 137 Cs in the diet. Overestimation of the amount of interindividual variability often resulted from confusion of uncertainty with variability. The spreads of the distributions for parameters describing interindividual variability were frequently increased to compensate for lack of knowledge about the uptake and metabolism of 137 Cs in the population. Accurate results produced by participants are attributable both to a participant's access to additional site-specific data or choice of appropriate site-specific assumptions and to the effects of compensatory errors

  10. CCHMM_PROF: a HMM-based coiled-coil predictor with evolutionary information

    DEFF Research Database (Denmark)

    Bartoli, Lisa; Fariselli, Piero; Krogh, Anders

    2009-01-01

    tools are available for predicting coiled-coil domains in protein sequences, including those based on position-specific score matrices and machine learning methods. RESULTS: In this article, we introduce a hidden Markov model (CCHMM_PROF) that exploits the information contained in multiple sequence...... alignments (profiles) to predict coiled-coil regions. The new method discriminates coiled-coil sequences with an accuracy of 97% and achieves a true positive rate of 79% with only 1% of false positives. Furthermore, when predicting the location of coiled-coil segments in protein sequences, the method reaches...

  11. A mathematical model for 137Cs uptake and release by filamentous algae

    International Nuclear Information System (INIS)

    Svadlenkova, M.; Dvorak, Z.; Slavik, O.; Institute of Hygiene and Epidemiology, Prague; Jaslovske Bohunice

    1989-01-01

    A mathematical model of the dynamics of radiocaesium transport in the aquatic phase-algae system is suggested in this work. Allowance is made for algae growth and for both reversible and irreversible absorption of this radionuclide by the algae. The algae biomass is divided hypothetically into two compartments with different exchange kinetics. The parameters of the model are time dependent. The model is quantified using experimental data for the concentrations of 137 Cs in Cladophora glomerata filamentous algae and in water, obtained in situ in the environment of a nuclear power station. The model fits the data resonably well and can be applied, for example, in bioindication of radioactivity in aquatic recipients in the environment of nuclear power stations. (author)

  12. Modelling of {sup 137}Cs behaviour in the soil-plant system following the application of ameliorants

    Energy Technology Data Exchange (ETDEWEB)

    Spiridonov, S.; Fesenko, S.; Sanzharova, N. [Russian Institute of Agricultural Radiology and Agroecology, Obninsk (Russian Federation)

    2004-07-01

    A set of countermeasures aimed at reducing {sup 137}Cs uptake by plant products includes agrochemical measures based on changes in the soil properties after the application of ameliorants. The dynamic models for studying the effect of the application of potassium fertilizers and dolomite powder on {sup 137}Cs accumulation in plants are presented. Conceptual approaches to the development of models are based on the identification of mechanisms governing a complex of physico-chemical processes in soil after the use of ameliorants. The following assumptions were used in the development of models: - dynamics of {sup 137}Cs distribution in each soil layer depends on the sorption processes characterized by different time to achieve quasi-equilibrium (exchangeable uptake and fixation by clay minerals) as well as on vertical migration process; - change in {sup 137}Cs content in soil solution results from the radionuclide sorption on selective and nonselective exchange sites; - uptake of extra amounts of K{sup +} and Ca{sup 2+} in soil solution produces effect on processes of {sup 137}Cs exchangeable sorption and initiate specific processes responsible for {sup 137}Cs fixation in the crystal lattice of clay minerals; - Ca{sup 2+} and K{sup +} cations have a competing effect on {sup 137}Cs uptake by plants from soil solution, which along with the fixation processes, causes lower accumulation of this radionuclide by plants during the application of ameliorants. The developed models were parameterized for soils of the coniferous forest located in the Bryansk region in area suffered from the radioactive fallout after the Chernobyl accident. Effects of ameliorants and time of their application on {sup 137}Cs behaviour in the soil-plant system are assessed. The contribution of soil chemical and biological processes to the decrease in the radionuclide uptake by plants is estimated. (author)

  13. Representing environment-induced helix-coil transitions in a coarse grained peptide model

    Science.gov (United States)

    Dalgicdir, Cahit; Globisch, Christoph; Sayar, Mehmet; Peter, Christine

    2016-10-01

    Coarse grained (CG) models are widely used in studying peptide self-assembly and nanostructure formation. One of the recurrent challenges in CG modeling is the problem of limited transferability, for example to different thermodynamic state points and system compositions. Understanding transferability is generally a prerequisite to knowing for which problems a model can be reliably used and predictive. For peptides, one crucial transferability question is whether a model reproduces the molecule's conformational response to a change in its molecular environment. This is of particular importance since CG peptide models often have to resort to auxiliary interactions that aid secondary structure formation. Such interactions take care of properties of the real system that are per se lost in the coarse graining process such as dihedral-angle correlations along the backbone or backbone hydrogen bonding. These auxiliary interactions may then easily overstabilize certain conformational propensities and therefore destroy the ability of the model to respond to stimuli and environment changes, i.e. they impede transferability. In the present paper we have investigated a short peptide with amphiphilic EALA repeats which undergoes conformational transitions between a disordered and a helical state upon a change in pH value or due to the presence of a soft apolar/polar interface. We designed a base CG peptide model that does not carry a specific (backbone) bias towards a secondary structure. This base model was combined with two typical approaches of ensuring secondary structure formation, namely a C α -C α -C α -C α pseudodihedral angle potential or a virtual site interaction that mimics hydrogen bonding. We have investigated the ability of the two resulting CG models to represent the environment-induced conformational changes in the helix-coil equilibrium of EALA. We show that with both approaches a CG peptide model can be obtained that is environment-transferable and that

  14. Cs-selective mineral adsorbents in columns: physico-chemical properties and modeling

    International Nuclear Information System (INIS)

    Michel, Caroline

    2015-01-01

    Following the nuclear disaster in Fukushima Dai-Ichi, thousands of tons of fresh water and seawater were used for cooling the reactors or contaminated as a result of groundwater seepage. Decontamination of these waters is complicated by the presence of other cations (Na + , K + , Ca 2+ , Mg 2+ ) naturally present in these waters. Decontamination process in columns packed was studied in this context with two types of mineral adsorbents: the TERMOXID 35 and the SORBMATECH 202. The first one is a commercial adsorbent and consists of mixed ferrocyanide K/Ni impregnated over a solid matrix Zr(OH) 4 . The second one was synthesized in CEA and is composed of ferrocyanide K/Cu impregnated over a solid matrix SiO 2 . Both materials have shown a high efficiency for Cs decontamination in seawater with K(d,Cs) of about 10 5 mL/g. Batch studies conducted in different solutions (pure water, fresh water and seawater) allowed determining sorption kinetics and ion exchange mechanisms responsible for the sorption of Cs + , taking into account competitive effects of the natural water cations (Na + , K + , Ca 2+ , Mg 2+ ). Modelling of batches was performed with the geochemical code CHESS considering competitive effects according to the Vanselow formalism and selectivity coefficients, developing a specific thermodynamic database. The performances of these materials were then tested in column. The operating parameters such as Darcy's velocity and the H/D ratio were studied for a proper functioning of this process. The T35 has proven to be less efficient mainly because of the slow diffusion of Cs in the pores of the material. The S 2 O 2 has proven to be a good candidate for the application of high flow rates. The breakthrough curves obtained in fresh water have been modelled with the reactive transport codes HYTEC and OPTIPUR using the CHESS thermodynamic database. This approach will eventually help to support the design of a decontamination unit by the operator. (author) [fr

  15. A review of {sup 137}Cs transfer to fungi and consequences for modelling environmental transfer

    Energy Technology Data Exchange (ETDEWEB)

    Gillett, A.G. E-mail: andy.gillett@nottingham.ac.uk; Crout, N.M.J

    2000-03-01

    A review of the published literature describing {sup 137}Cs transfer to fungi was carried out, summarising the collated data to determine factors controlling transfer and identify an appropriate modelling approach to predict future contamination. {sup 137}Cs transfer ratios (TR) are derived for fungi species collected within Europe and the CIS. Considerable variability in TRs is demonstrated, with TRs varying between <0.001 and >10 m{sup 2} kg{sup -1} across all species and over three orders of magnitude for individual species (e.g. Boletus badius). Generally, meta-information (such as habitat and soil attributes) is poorly reported in the literature so that classification of the TR is limited to the effect of nutritional type (P<0.025) in the order mycorrhizal>saprophytic{approx}parasitic. Analysis of the literature data set (a heterogeneous source) suggests that there is no statistical evidence to indicate a decrease in TRs for 10 years after the Chernobyl accident. Spatial analysis of a data set for Belgium indicates variability in {sup 137}Cs transfer within a sampling location, such that fruitbodies collected over a scale of approximately 5 km would show activities as variable as those collected over a much larger scale ({approx} or>50 km). Therefore, it is proposed that the collated data sets for individual species can be used to derive 'best estimates' for the parameters describing the distribution of TRs. These can then be used to estimate an 'effective' TR, which, when combined with local soil deposition level and frequency and effect of culinary practices, can give an estimate of the activity of fungi consumed by the general population.

  16. A review of 137Cs transfer to fungi and consequences for modelling environmental transfer

    International Nuclear Information System (INIS)

    Gillett, A.G.; Crout, N.M.J.

    2000-01-01

    A review of the published literature describing 137 Cs transfer to fungi was carried out, summarising the collated data to determine factors controlling transfer and identify an appropriate modelling approach to predict future contamination. 137 Cs transfer ratios (TR) are derived for fungi species collected within Europe and the CIS. Considerable variability in TRs is demonstrated, with TRs varying between 10 m 2 kg -1 across all species and over three orders of magnitude for individual species (e.g. Boletus badius). Generally, meta-information (such as habitat and soil attributes) is poorly reported in the literature so that classification of the TR is limited to the effect of nutritional type (P saprophytic∼parasitic. Analysis of the literature data set (a heterogeneous source) suggests that there is no statistical evidence to indicate a decrease in TRs for 10 years after the Chernobyl accident. Spatial analysis of a data set for Belgium indicates variability in 137 Cs transfer within a sampling location, such that fruitbodies collected over a scale of approximately 5 km would show activities as variable as those collected over a much larger scale (∼ or>50 km). Therefore, it is proposed that the collated data sets for individual species can be used to derive 'best estimates' for the parameters describing the distribution of TRs. These can then be used to estimate an 'effective' TR, which, when combined with local soil deposition level and frequency and effect of culinary practices, can give an estimate of the activity of fungi consumed by the general population

  17. The adsorption of Cs+, Sr2+ and Ni2+ on bitumen: a mechanistic model

    International Nuclear Information System (INIS)

    Loon, L.R. Van; Kopajtic, Z.

    1991-01-01

    The adsorption of radionuclides on the waste matrix is a positive effect and contributes to the retardation of released radionuclides migrating to the geo-and biosphere. For the safety assessment studies, it is important to know whether or not radionuclides do adsorb on the waste matrix. In the present work the adsorption of 134 Cs + , 85 Sr 2+ and 63 Ni 2+ on bitumen was studied as a function of the pH and ionic strength of the equilibrium solution. Bitumen emulsions with well defined surfaces were used. The surface of bitumen is negatively charged due to the deprotonation of weak acid carboxyl groups at the interface. The functional group density amounts to 1.37.10 18 groups/m 2 and their deprotonation behaviour can be well described by the 'Ionizable Surface Group' model. Cs + , Sr 2+ and Ni 2+ adsorb on the surface by three different processes, i.e. ion exchange, outer sphere complexation and inner sphere surface complexation respectively. The adsorption depends on the pH and the ionic strength of the contact solution. Under near field conditions, Cs + and Sr 2+ do not adsorb on the bitumen due to the competition with Na + , K + and Ca 2+ present in the cement pore water in contact with the bitumen. Ni 2+ adsorption can also be neglected because the formation of neutral and anionic hydroxo complexes in solution competes strongly with the adsorption reaction. Other hydrolysable radionuclides of interest are expected to behave similarly to Ni 2+ . The main conclusion of the study is that the adsorption of radionuclides under near field conditions is expected to be very low. Consequently, this process need not to be considered in safety assessment studies. (author) figs., tabs., 30 refs

  18. Local-scale modelling of the releases of 137-Cs and 90-Sr from Fukushima NPP into the Pacific Ocean

    International Nuclear Information System (INIS)

    Raul, Perianez

    2013-01-01

    The dispersion of 137-Cs and 90-Sr released from Fukushima nuclear power plant to the sea after the March 11th 2011 tsunami has been studied using a numerical model. The 3D dispersion model consists of an advection/diffusion equation with terms describing uptake/release reactions between water and seabed sediments. The dispersion model has been fed with daily currents provided by JCOPE2 ocean model. Seabed sediment 137-Cs computed patterns have been compared with observations. The impact of tides and of atmospheric deposition on sediment contamination has been evaluated as well. First simulations carried out for Sr-90 are described. An evaluation of the amount of this radionuclide released to the sea has been made using a numerical model for the first time. Calculated vertical profiles of this radionuclide have been compared with measured ones. Finally, the variability in 90-Sr/137-Cs activity ratios has been analysed with the model

  19. Computational Fluid Dynamics Model for Solar Thermal Storage Tanks with Helical Jacket Heater and Upper Spiral Coil Heater

    Energy Technology Data Exchange (ETDEWEB)

    Baek, Seung Man [Seoul Nat' l Univ., Seoul (Korea, Republic of); Zhong, Yiming; Nam, Jin Hyun [Daegu Univ., Daegu (Korea, Republic of); Chung, Jae Dong [Sejong Univ., Seoul (Korea, Republic of); Hong, Hiki [Kyung Hee Univ., Seoul (Korea, Republic of)

    2013-04-15

    In a solar domestic hot water (Shadow) system, solar energy is collected using collector panels, transferred to a circulating heat transfer fluid (brine), and eventually stored in a thermal storage tank (Test) as hot water. In this study, a computational fluid dynamics (CAD) model was developed to predict the solar thermal energy storage in a hybrid type Test equipped with a helical jacket heater (mantle heat exchanger) and an immersed spiral coil heater. The helical jacket heater, which is the brine flow path attached to the side wall of a Test, has advantages including simple system design, low brine flow rate, and enhanced thermal stratification. In addition, the spiral coil heater further enhances the thermal performance and thermal stratification of the Test. The developed model was validated by the good agreement between the CAD results and the experimental results performed with the hybrid-type Test in Shadow settings.

  20. Computational Fluid Dynamics Model for Solar Thermal Storage Tanks with Helical Jacket Heater and Upper Spiral Coil Heater

    International Nuclear Information System (INIS)

    Baek, Seung Man; Zhong, Yiming; Nam, Jin Hyun; Chung, Jae Dong; Hong, Hiki

    2013-01-01

    In a solar domestic hot water (Shadow) system, solar energy is collected using collector panels, transferred to a circulating heat transfer fluid (brine), and eventually stored in a thermal storage tank (Test) as hot water. In this study, a computational fluid dynamics (CAD) model was developed to predict the solar thermal energy storage in a hybrid type Test equipped with a helical jacket heater (mantle heat exchanger) and an immersed spiral coil heater. The helical jacket heater, which is the brine flow path attached to the side wall of a Test, has advantages including simple system design, low brine flow rate, and enhanced thermal stratification. In addition, the spiral coil heater further enhances the thermal performance and thermal stratification of the Test. The developed model was validated by the good agreement between the CAD results and the experimental results performed with the hybrid-type Test in Shadow settings

  1. Modeling {sup 137}Cs bioaccumulation in the salmon–resident killer whale food web of the Northeastern Pacific following the Fukushima Nuclear Accident

    Energy Technology Data Exchange (ETDEWEB)

    Alava, Juan José, E-mail: jalavasa@sfu.ca; Gobas, Frank A.P.C.

    2016-02-15

    To track the long term bioaccumulation of {sup 137}Cs in marine organisms off the Pacific Northwest coast of Canada, we developed a time dependent bioaccumulation model for {sup 137}Cs in a marine mammalian food web that included fish-eating resident killer whales. The model outcomes show that {sup 137}Cs can be expected to gradually bioaccumulate in the food web over time as demonstrated by the increase of the apparent trophic magnification factor of {sup 137}Cs, ranging from 0.76 after 1 month of exposure to 2.0 following 30 years of exposure. {sup 137}Cs bioaccumulation is driven by relatively rapid dietary uptake rates, moderate depuration rates in lower trophic level organisms and slow elimination rates in high trophic level organisms. Model estimates of the {sup 137}Cs activity in species of the food web, based on current measurements and forecasts of {sup 137}Cs activities in oceanic waters and sediments off the Canadian Pacific Northwest, indicate that the long term {sup 137}Cs activities in fish species including Pacific herring, wild Pacific salmon, sablefish and halibut will remain well below the current {sup 137}Cs-Canada Action Level for consumption (1000 Bq/kg) following a nuclear emergency. Killer whales and Pacific salmon are expected to exhibit the largest long term {sup 137}Cs activities and may be good sentinels for monitoring {sup 137}Cs in the region. Assessment of the long term consequences of {sup 137}Cs releases from the Fukushima aftermath should consider the extent of ecological magnification in addition to ocean dilution. - Highlights: • A food web bioaccumulation model to assess the biomagnification of {sup 137}Cs is developed. • Cesium 137 exhibits bioaccumulation over time as simulated by the model. • Predicted activities in marine biota are below {sup 137}Cs-food consumption benchmarks. • Long-term monitoring of {sup 137}Cs in the ocean will improve the model predictions.

  2. Modeling 137Cs bioaccumulation in the salmon–resident killer whale food web of the Northeastern Pacific following the Fukushima Nuclear Accident

    International Nuclear Information System (INIS)

    Alava, Juan José; Gobas, Frank A.P.C.

    2016-01-01

    To track the long term bioaccumulation of 137 Cs in marine organisms off the Pacific Northwest coast of Canada, we developed a time dependent bioaccumulation model for 137 Cs in a marine mammalian food web that included fish-eating resident killer whales. The model outcomes show that 137 Cs can be expected to gradually bioaccumulate in the food web over time as demonstrated by the increase of the apparent trophic magnification factor of 137 Cs, ranging from 0.76 after 1 month of exposure to 2.0 following 30 years of exposure. 137 Cs bioaccumulation is driven by relatively rapid dietary uptake rates, moderate depuration rates in lower trophic level organisms and slow elimination rates in high trophic level organisms. Model estimates of the 137 Cs activity in species of the food web, based on current measurements and forecasts of 137 Cs activities in oceanic waters and sediments off the Canadian Pacific Northwest, indicate that the long term 137 Cs activities in fish species including Pacific herring, wild Pacific salmon, sablefish and halibut will remain well below the current 137 Cs-Canada Action Level for consumption (1000 Bq/kg) following a nuclear emergency. Killer whales and Pacific salmon are expected to exhibit the largest long term 137 Cs activities and may be good sentinels for monitoring 137 Cs in the region. Assessment of the long term consequences of 137 Cs releases from the Fukushima aftermath should consider the extent of ecological magnification in addition to ocean dilution. - Highlights: • A food web bioaccumulation model to assess the biomagnification of 137 Cs is developed. • Cesium 137 exhibits bioaccumulation over time as simulated by the model. • Predicted activities in marine biota are below 137 Cs-food consumption benchmarks. • Long-term monitoring of 137 Cs in the ocean will improve the model predictions.

  3. Numerical simulations to model laser-driven coil-capacitor targets for generation of kilo-Tesla magnetic fields

    Directory of Open Access Journals (Sweden)

    F. Schillaci

    2018-02-01

    Full Text Available A coil-capacitor target is modeled using FEM simulations and analytical calculations, which allow to explain the time evolution of such complex target during magnetic field production driven by the flow of an extremely high current generated through the interaction with a high power laser. The numerical model includes a detailed study of the magnetic field produced by the coil-capacitor target, both in the static and transient cases, as well as magnetic force and Joule heating. The model is validated by experimental data reported in literature and can be of interest for several applications. As an example, the combination of two synchronized nanosecond lasers with the purpose of producing a plasma responsible of the proton-boron (p+ + 11B → 8.5 MeV + 3α fusion reaction, and energizing two multi-turn coils with the main purpose of confining such a plasma could enhance the reaction rate. The preliminary conceptual design of a magnetic mirror configuration to be used for confining protons and boron ions up to a few MeV/u in a region of less than 1 mm2 is briefly reported.

  4. Numerical simulations to model laser-driven coil-capacitor targets for generation of kilo-Tesla magnetic fields

    Science.gov (United States)

    Schillaci, F.; De Marco, M.; Giuffrida, L.; Fujioka, S.; Zhang, Z.; Korn, G.; Margarone, D.

    2018-02-01

    A coil-capacitor target is modeled using FEM simulations and analytical calculations, which allow to explain the time evolution of such complex target during magnetic field production driven by the flow of an extremely high current generated through the interaction with a high power laser. The numerical model includes a detailed study of the magnetic field produced by the coil-capacitor target, both in the static and transient cases, as well as magnetic force and Joule heating. The model is validated by experimental data reported in literature and can be of interest for several applications. As an example, the combination of two synchronized nanosecond lasers with the purpose of producing a plasma responsible of the proton-boron (p+ + 11B → 8.5 MeV + 3α) fusion reaction, and energizing two multi-turn coils with the main purpose of confining such a plasma could enhance the reaction rate. The preliminary conceptual design of a magnetic mirror configuration to be used for confining protons and boron ions up to a few MeV/u in a region of less than 1 mm2 is briefly reported.

  5. Mechanical and Electrical Modeling of Strands in Two ITER CS Cable Designs

    CERN Document Server

    Torre, A; Ciazynski, D

    2014-01-01

    Following the test of the first Central Solenoid (CS) conductor short samples for the International Thermonuclear Experimental Reactor (ITER) in the SULTAN facility, Iter Organization (IO) decided to manufacture and test two alternate samples using four different cable designs. These samples, while using the same Nb$_{3}$Sn strand, were meant to assess the influence of various cable design parameters on the conductor performance and behavior under mechanical cycling. In particular, the second of these samples, CSIO2, aimed at comparing designs with modified cabling twist pitches sequences. This sample has been tested, and the two legs exhibited very different behaviors. To help understand what could lead to such a difference, these two cables were mechanically modeled using the MULTIFIL code, and the resulting strain map was used as an input into the CEA electrical code CARMEN. This article presents the main data extracted from the mechanical simulation and its use into the electrical modeling of individual s...

  6. The use of a numerical mass-balance model to estimate rates of soil redistribution on uncultivated land from 137Cs measurements

    International Nuclear Information System (INIS)

    Owens, P.N.; Walling, D.E.

    1988-01-01

    A numerical mass-balance model is developed which can be used to estimate rates of soil redistribution on uncultivated land from measurements of bombderived 137 Cs inventories. The model uses a budgeting approach, which takes account of temporal variations in atmospheric fallout of 137 Cs, radioactive decay, and net gains or losses of 137 Cs due to erosion and deposition processes, combined with parameters which describe internal 137 Cs redistribution processes, to estimate the 137 Cs content of topsoil and the 137 Cs inventory at specific points, from the start of 137 Cs fallout in the 1950s to the present day. The model is also able to account for potential differences in particle size composition and organic matter content between mobilised soil particles and the original soil, and the effect that these may have on 137 Cs concentrations and inventories. By running the model for a range of soil erosion and deposition rates, a calibration relationship can be constructed which relates the 137 Cs inventory at a sampling point to the average net soil loss or gain at that location. In addition to the magnitude and temporal distribution of the 137 Cs atmospheric fallout flux, the soil redistribution rates estimated by the model are sensitive to parameters which describe the relative texture and organic matter content of the eroded or deposited material, and the ability of the soil to retain 137 Cs in the upper part of the soil profile. (Copyright (c) 1988 Elsevier Science B.V., Amsterdam. All rights reserved.)

  7. Investigating the effect of coil model losses on computational electromagnetic exposure of an ASTM phantom at 64 MHz MRI.

    Science.gov (United States)

    Kozlov, Mikhail; Horner, Marc; Kainz, Wolfgang; Angelone, Leonardo M

    2017-07-01

    The goal of this work is to investigate the effect of coil losses on the electromagnetic field generated in an ASTM phantom by a birdcage coil. The study was based on different numerical implementations of an RF body coil at 64 MHz, using the same 3D EM and RF circuit co-simulation procedure. The coil quality factor was evaluated with respect to losses due to power feed mismatch and to resistive losses of the coil components. The results of the study showed that the magnetic field at the coil iso-center, normalized to the square root of the whole body specific absorption rate, depends on the coil quality factor.

  8. Estimation Of 137Cs Using Atmospheric Dispersion Models After A Nuclear Reactor Accident

    Science.gov (United States)

    Simsek, V.; Kindap, T.; Unal, A.; Pozzoli, L.; Karaca, M.

    2012-04-01

    Nuclear energy will continue to have an important role in the production of electricity in the world as the need of energy grows up. But the safety of power plants will always be a question mark for people because of the accidents happened in the past. Chernobyl nuclear reactor accident which happened in 26 April 1986 was the biggest nuclear accident ever. Because of explosion and fire large quantities of radioactive material was released to the atmosphere. The release of the radioactive particles because of accident affected not only its region but the entire Northern hemisphere. But much of the radioactive material was spread over west USSR and Europe. There are many studies about distribution of radioactive particles and the deposition of radionuclides all over Europe. But this was not true for Turkey especially for the deposition of radionuclides released after Chernobyl nuclear reactor accident and the radiation doses received by people. The aim of this study is to determine the radiation doses received by people living in Turkish territory after Chernobyl nuclear reactor accident and use this method in case of an emergency. For this purpose The Weather Research and Forecasting (WRF) Model was used to simulate meteorological conditions after the accident. The results of WRF which were for the 12 days after accident were used as input data for the HYSPLIT model. NOAA-ARL's (National Oceanic and Atmospheric Administration Air Resources Laboratory) dispersion model HYSPLIT was used to simulate the 137Cs distrubition. The deposition values of 137Cs in our domain after Chernobyl Nuclear Reactor Accident were between 1.2E-37 Bq/m2 and 3.5E+08 Bq/m2. The results showed that Turkey was affected because of the accident especially the Black Sea Region. And the doses were calculated by using GENII-LIN which is multipurpose health physics code.

  9. Endovascular treatment of wide-necked aneurysms using stents combined with electrolytic detachable coils in a canine model

    International Nuclear Information System (INIS)

    Liu Jianmin; Zhang Xin; Zhou Xiaoping; Hong Bo; Xu Yi; Huang Qinghai; Zhang Long; She Jiagui; Zhao Rui

    2004-01-01

    Objective: To assess hemodynamics and histology of the aneurysms by treating experimental wide-necked aneurysms endovascularly with a combination of stents and electrolytic detachable coils. Methods: An experimental model was surgically constructed in the necks of six canines for simulating intracranial wide-necked aneurysms. Balloon-expandable metal stents were positioned across the aneurysms in bilateral carotid arteries of six canines with additional intraaneurysmal placement of detachable microcoils in only unilateral carotid artery of each canine. Sonography and angiography were performed in different stages and histologic examinations were achieved finally. Results: Stent placement was successful in all six canines. Aneurysms treated with only stents placement showed no significant thrombus formation with slow growing of neointima over the neck of the aneurysm. Thrombosis occurred in the aneurysms treated with stents and coils in a short time and neointima covered the neck of the aneurysms completely. Conclusions: Endovascular treatment of wide-necked aneurysms using stents combined with electrolytic detachable coils may prevent re-rupture of the aneurysms and promote neointima formation over the neck of the aneurysms. (authors)

  10. ITER toroidal field model coil (TFMC). Test and analysis summary report (testing handbook) chapter 3 TOSKA FACILITY

    International Nuclear Information System (INIS)

    Ulbricht, A.

    2001-05-01

    In the frame of a contract between the ITER (International Thermonuclear Experimental Reactor) Director and the European Home Team Director was concluded the extension of the TOSKA facility of the Forschungszentrum Karlsruhe as test bed for the ITER toroidal field model coil (TFMC), one of the 7 large research and development projects of the ITER EDA (Engineering Design Activity). The report describes the work and development, which were performed together with industry to extend the existing components and add new components. In this frame a new 2 kW refrigerator was added to the TOSKA facility including the cold lines to the Helium dewar in the TOSKA experimental area. The measuring and control system as well as data acquisition was renewed according to the state-of-the-art. Two power supplies (30 kA, 50 kA) were switched in parallel across an Al bus bar system and combined with an 80 kA dump circuit. For the test of the TFMC in the background field of the EURATOM LCT coil a new 20 kA power supply was taken into operation with the existing 20 kA discharge circuit. Two forced flow cooled 80 kA current leads for the TFMC were developed. The total lifting capacity for loads in the TOSKA building was increased by an ordered new 80 t crane with a suitable cross head (125 t lifting capacity +5 t net mass) to 130 t for assembling and installation of the test arrangement. Numerous pre-tests and development and adaptation work was required to make the components suitable for application. The 1.8 K test of the EURATOM LCT coil and the test of the W 7-X prototype coil count to these tests as overall pre-tests. (orig.)

  11. The kinetic model of 137Cs behavior in the system 'soil - plant' accounting of agrochemical soil properties

    International Nuclear Information System (INIS)

    Prister, B.S.; Vinogradskaya, V.D.

    2011-01-01

    From data of the long-term radiological monitoring contaminated after Chernobyl accident lands of Ukraine investigated the dynamics of 137 Cs accumulation by plants in a wide range of environmental conditions. On the basis of modern concepts about the transformation of radionuclides forms in the soil created kinetic model the 137 Cs behavior in the system 'soil - plant', which uses as an argument to a complex estimation of agrochemical properties of soil, calculated according to the triad - the reaction of the soil solution, organic matter content and the amount of absorbed bases. Establish the high accuracy of the model and estimate the possibility of its use for other territories.

  12. Using the integral equations method to model a 2G racetrack coil with anisotropic critical current dependence

    Science.gov (United States)

    Martins, F. G. R.; Sass, F.; Barusco, P.; Ferreira, A. C.; de Andrade, R., Jr.

    2017-11-01

    Second-generation (2G) superconducting wires have already proved their potential in several applications. These materials have a highly nonlinear behavior that turns an optimized engineering project into a challenge. Between several numerical techniques that can be used to perform this task, the integral equations (IE) method stands out for avoiding mesh problems by representing the 2G wire cross-sectional area by a line. While most applications need to be represented in a 3D geometry, the IE is limited to longitudinal or axisymmetric models. This work demonstrates that a complex 3D geometry can be modeled by several coupled simulations using the IE method. In order to prove this statement, the proposed technique was used to simulate a 2G racetrack coil considering the self-field magnitude (B) and incidence angle (θ) on the tape. The J c characteristic was modeled in terms of parallel and normal to the tape plane magnetic field components (J c(B ∥ , B ⊥)) obtained from a V-I(B, θ) characterization of a tape segment. This result was implemented using commercial software with both A-V (vector magnetic potential and scalar voltage potential) and IE coupled simulations solved by finite elements. This solution bypasses the meshing problem due to the tapes slim geometry, considering each turn a single 1D model, all magnetically interacting in two 2D models. The simulations results are in good agreement to what was both expected and observed in the literature. The simulation is compared to the measured V-I characteristic for a single pancake racetrack coil built with same geometry as its simulation models, and a theoretical study demonstrates the possibilities of the proposed tool for analyzing a racetrack coil current density and electric field behavior in each of its turns.

  13. An improved FEM model for computing transport AC loss in coils made of RABiTS YBCO coated conductors for electric machines

    International Nuclear Information System (INIS)

    Ainslie, Mark D; Yuan Weijia; Flack, Timothy J; Coombs, Timothy A; Rodriguez-Zermeno, Victor M; Hong Zhiyong

    2011-01-01

    AC loss can be a significant problem for any applications that utilize or produce an AC current or magnetic field, such as an electric machine. The authors investigate the electromagnetic properties of high temperature superconductors with a particular focus on the AC loss in superconducting coils made from YBCO coated conductors for use in an all-superconducting electric machine. This paper presents an improved 2D finite element model for the cross-section of such coils, based on the H formulation. The model is used to calculate the transport AC loss of a racetrack-shaped coil using constant and magnetic field-dependent critical current densities, and the inclusion and exclusion of a magnetic substrate, as found in RABiTS (rolling-assisted biaxially textured substrate) YBCO coated conductors. The coil model is based on the superconducting stator coils used in the University of Cambridge EPEC Superconductivity Group's all-superconducting permanent magnet synchronous motor design. To validate the modeling results, the transport AC loss of a stator coil is measured using an electrical method based on inductive compensation by means of a variable mutual inductance. Finally, the implications of the findings on the performance of the motor are discussed.

  14. An improved FEM model for computing transport AC loss in coils made of RABiTS YBCO coated conductors for electric machines

    Energy Technology Data Exchange (ETDEWEB)

    Ainslie, Mark D; Yuan Weijia; Flack, Timothy J; Coombs, Timothy A [Department of Engineering, University of Cambridge, 9 J J Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Rodriguez-Zermeno, Victor M [Department of Mathematics, Technical University of Denmark, Kongens Lyngby 2800 (Denmark); Hong Zhiyong, E-mail: mda36@cam.ac.uk [School of Electronic, Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai (China)

    2011-04-15

    AC loss can be a significant problem for any applications that utilize or produce an AC current or magnetic field, such as an electric machine. The authors investigate the electromagnetic properties of high temperature superconductors with a particular focus on the AC loss in superconducting coils made from YBCO coated conductors for use in an all-superconducting electric machine. This paper presents an improved 2D finite element model for the cross-section of such coils, based on the H formulation. The model is used to calculate the transport AC loss of a racetrack-shaped coil using constant and magnetic field-dependent critical current densities, and the inclusion and exclusion of a magnetic substrate, as found in RABiTS (rolling-assisted biaxially textured substrate) YBCO coated conductors. The coil model is based on the superconducting stator coils used in the University of Cambridge EPEC Superconductivity Group's all-superconducting permanent magnet synchronous motor design. To validate the modeling results, the transport AC loss of a stator coil is measured using an electrical method based on inductive compensation by means of a variable mutual inductance. Finally, the implications of the findings on the performance of the motor are discussed.

  15. Modelling the cancer growth process by Stochastic Differential Equations with the effect of Chondroitin Sulfate (CS) as anticancer therapeutics

    Science.gov (United States)

    Syahidatul Ayuni Mazlan, Mazma; Rosli, Norhayati; Jauhari Arief Ichwan, Solachuddin; Suhaity Azmi, Nina

    2017-09-01

    A stochastic model is introduced to describe the growth of cancer affected by anti-cancer therapeutics of Chondroitin Sulfate (CS). The parameters values of the stochastic model are estimated via maximum likelihood function. The numerical method of Euler-Maruyama will be employed to solve the model numerically. The efficiency of the stochastic model is measured by comparing the simulated result with the experimental data.

  16. Design of the pancake-winding central solenoid coil

    International Nuclear Information System (INIS)

    Yoshida, Kiyoshi; Nishi, Masataka; Tsuji, Hirosi

    1995-01-01

    There was a debate over whether a pancake-winding or layer-winding technique is more appropriate for the Central Solenoid (CS) coil for ITER superconducting magnet. The layer-winding CS has the advantage of homogeneous winding supporting the TF centering force without weak joints, but has many difficulties during manufacturing and quality control. On other hand, the pancake-winding has the advantage of better quality control during manufacturing and module testing but has difficulties with joints and feeders, and pipes located in the load path of the bucking force from the toroidal field coils. The compact joints, reinforcement by preformed amour, sharp bending, and double seals are applied to the design of pancake-winding CS coil and demonstrated by hardware developments. The pancake-winding CS coil by using modified existing technology is compatible with the bucking concept of the ITER magnet system. (author)

  17. Estimates of soil erosion and deposition of cultivated soil of Nakhla watershed, Morocco, using 137Cs technique and calibration models

    International Nuclear Information System (INIS)

    Bouhlassa, S.; Moukhchane, M.; Aiachi, A.

    2000-01-01

    Despite the effective threat of erosion, for soil preservation and productivity in Morocco, there is still only limited information on rates of soil loss involved. This study is aimed to establish long-term erosion rates on cultivated land in the Nakhla watershed located in the north of the country, using 137 Cs technique. Two sampling strategies were adopted. The first is aimed at establishing areal estimates of erosion, whereas the second, based on a transect approach, intends to determine point erosion. Twenty-one cultivated sites and seven undisturbed sites apparently not affected by erosion or deposition were sampled to 35 cm depth. Nine cores were collected along the transect of 149 m length. The assessment of erosion rates with models varying in complexity from the simple Proportional Model to more complex Mass Balance Models which attempts to include the processes controlling the redistribution of 137 Cs in soil, enables us to demonstrate the significance of soil erosion problem on cultivated land. Erosion rates rises up to 50 t ha -1 yr -1 . The 137 Cs derived erosion rates provide a reliable representation of water erosion pattern in the area, and indicate the importance of tillage process on the redistribution of 137 Cs in soil. For aggrading sites a Constant Rate Supply (CRS) Model had been adapted and introduced to estimate easily the depositional rate. (author) [fr

  18. Triple Halo Coil: Development and Comparison with Other TMS Coils

    Science.gov (United States)

    Rastogi, Priyam; Hadimani, Ravi; Jiles, David

    Transcranial Magnetic Stimulation (TMS) is a non-invasive stimulation technique that can be used for the treatment of various neurological disorders such as Parkinson's Disease, PTSD, TBI and anxiety by regulating synaptic activity. TMS is FDA approved for the treatment of major depressive disorder. There is a critical need to develop deep TMS coils that can stimulate deeper regions of the brain without excessively stimulating the cortex in order to provide an alternative to surgical methods. We have developed a novel multi-coil configuration called ``Triple Halo Coil'' (THC) that can stimulate deep brain regions. Investigation of induced electric and magnetic field in these regions have been achieved by computer modelling. Comparison of the results due to THC configuration have been conducted with other TMS coils such as ``Halo Coil'', circular coil and ``Figure of Eight'' coil. There was an improvement of more than 15 times in the strength of magnetic field, induced by THC configuration at 10 cm below the vertex of the head when compared with the ``Figure of Eight'' coil alone. Carver Charitable Trust.

  19. Comparative modeling analyses of Cs-137 fate in the rivers impacted by Chernobyl and Fukushima accidents

    Energy Technology Data Exchange (ETDEWEB)

    Zheleznyak, M.; Kivva, S. [Institute of Environmental Radioactivity, Fukushima University (Japan)

    2014-07-01

    The consequences of two largest nuclear accidents of the last decades - at Chernobyl Nuclear Power Plant (ChNPP) (1986) and at Fukushima Daiichi NPP (FDNPP) (2011) clearly demonstrated that radioactive contamination of water bodies in vicinity of NPP and on the waterways from it, e.g., river- reservoir water after Chernobyl accident and rivers and coastal marine waters after Fukushima accident, in the both cases have been one of the main sources of the public concerns on the accident consequences. The higher weight of water contamination in public perception of the accidents consequences in comparison with the real fraction of doses via aquatic pathways in comparison with other dose components is a specificity of public perception of environmental contamination. This psychological phenomenon that was confirmed after these accidents provides supplementary arguments that the reliable simulation and prediction of the radionuclide dynamics in water and sediments is important part of the post-accidental radioecological research. The purpose of the research is to use the experience of the modeling activities f conducted for the past more than 25 years within the Chernobyl affected Pripyat River and Dnieper River watershed as also data of the new monitoring studies in Japan of Abukuma River (largest in the region - the watershed area is 5400 km{sup 2}), Kuchibuto River, Uta River, Niita River, Natsui River, Same River, as also of the studies on the specific of the 'water-sediment' {sup 137}Cs exchanges in this area to refine the 1-D model RIVTOX and 2-D model COASTOX for the increasing of the predictive power of the modeling technologies. The results of the modeling studies are applied for more accurate prediction of water/sediment radionuclide contamination of rivers and reservoirs in the Fukushima Prefecture and for the comparative analyses of the efficiency of the of the post -accidental measures to diminish the contamination of the water bodies. Document

  20. Global Distributions of {sup 137}Cs, {sup 239,240}Pu and the Ratio of {sup 239,240}Pu/{sup 137}Cs in an Ocean General Circulation Model

    Energy Technology Data Exchange (ETDEWEB)

    Tsumune, D.; Tsubono, T.; Misumi, K.; Yoshida, Y. [Environmental Research Laboratory, Central Research Institute of Electric Power Industry, Abiko (Japan); Aoyama, M. [Geochemical Research Department, Meteorological Research Institute, Tsukuba (Japan); Hirose, K. [Sophia University, Tokyo (Japan)

    2013-07-15

    The spatial distributions and the temporal variations of {sup 137}Cs and {sup 239,240}Pu concentrations were simulated by using an ocean general circulation model (OGCM). These radionuclides are introduced into the ocean by global fallout originating from atmospheric nuclear weapons tests. {sup 137}Cs derived from global fallout is transported into the ocean interior by advection and diffusion, and the {sup 137}Cs concentration is reduced by radioactive decay. In contrast to {sup 137}Cs, {sup 239,240}Pu, which is a particle reactive radionuclide, is a biogeochemical tracer. The global distribution of the {sup 239,240}Pu{sup /137}Cs ratio was investigated in an OGCM with a biogeochemical process model. A half regeneration depth (HRD) of {sup 239,240}Pu was estimated from curve fitting of the vertical profile of the {sup 239,240}Pu/{sup 137}Cs ratio. Simulated distribution of the HRD is in good agreement with observation, except in the subarctic gyre. The HRD is a good tool to improve the parameters in the biogeochemical process. (author)

  1. Assessment of wind characteristics and atmospheric dispersion modeling of 137Cs on the Barakah NPP area in the USA

    International Nuclear Information System (INIS)

    Lee, Jong Kuk; Lee, Kun Jai; Yun, Jong IL; Kim, Jae Chul; Belorid, Miloslav; Beeley, Philip A.

    2014-01-01

    This paper presents the results of an analysis of wind characteristics and atmosphere dispersion modeling that are based on computational simulation and part of a preliminary study evaluating environmental radiation monitoring system (ERMS) positions within the Barakah nuclear power plant (BNPP). The return period of extreme wind speed was estimated using the Weibull distribution over the life time of the BNPP. In the annual meteorological modeling, the winds from the north and west accounted for more than 90 % of the wind directions. Seasonal effects were not represented. However, a discrepancy in the tendency between daytime and nighttime was observed. Six variations of cesium-137 ( 137 Cs) dispersion test were simulated under severe accident condition. The 137 Cs dispersion was strongly influenced by the direction and speed of the main wind. A virtual receptor was set and calculated for observation of the 137 Cs movement and accumulation. The results of the surface roughness effect demonstrated that the deposition of 137 Cs was affected by surface condition. The results of these studies offer useful information for developing environmental radiation monitoring systems (ERMSs) for the BNPP and can be used to assess the environmental effects of new nuclear power plant.

  2. PDX toroidal field coils stress analysis

    International Nuclear Information System (INIS)

    Nikodem, Z.D.; Smith, R.A.

    1975-01-01

    A method used in the stress analysis of the PDX toroidal field coil is developed. A multilayer coil design of arbitrary dimensions in the shape of either a circle or an oval is considered. The analytical model of the coil and the supporting coil case with connections to the main support structure is analyzed using the finite element technique. The three dimensional magnetic fields and the non-uniform body forces which are a loading condition on a coil due to toroidal and poloidal fields are calculated. The method of analysis permits rapid and economic evaluations of design changes in coil geometry as well as in coil support structures. Some results pertinent to the design evolution and their comparison are discussed. The results of the detailed stress analysis of the final coil design due to toroidal field, poloidal field and temperature loads are presented

  3. Modeling (137)Cs bioaccumulation in the salmon-resident killer whale food web of the Northeastern Pacific following the Fukushima Nuclear Accident.

    Science.gov (United States)

    Alava, Juan José; Gobas, Frank A P C

    2016-02-15

    To track the long term bioaccumulation of (137)Cs in marine organisms off the Pacific Northwest coast of Canada, we developed a time dependent bioaccumulation model for (137)Cs in a marine mammalian food web that included fish-eating resident killer whales. The model outcomes show that (137)Cs can be expected to gradually bioaccumulate in the food web over time as demonstrated by the increase of the apparent trophic magnification factor of (137)Cs, ranging from 0.76 after 1 month of exposure to 2.0 following 30 years of exposure. (137)Cs bioaccumulation is driven by relatively rapid dietary uptake rates, moderate depuration rates in lower trophic level organisms and slow elimination rates in high trophic level organisms. Model estimates of the (137)Cs activity in species of the food web, based on current measurements and forecasts of (137)Cs activities in oceanic waters and sediments off the Canadian Pacific Northwest, indicate that the long term (137)Cs activities in fish species including Pacific herring, wild Pacific salmon, sablefish and halibut will remain well below the current (137)Cs-Canada Action Level for consumption (1000 Bq/kg) following a nuclear emergency. Killer whales and Pacific salmon are expected to exhibit the largest long term (137)Cs activities and may be good sentinels for monitoring (137)Cs in the region. Assessment of the long term consequences of (137)Cs releases from the Fukushima aftermath should consider the extent of ecological magnification in addition to ocean dilution. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. A model for the transfer of 137Cs from the water to the phytoplankton and simulation of laboratory experiments

    International Nuclear Information System (INIS)

    Smitz, J.S.; Everbecq, E.; Comeliau, B.

    1987-01-01

    Modelisation of the contamination/decontamination phenomenon of the water/algae Scenedesmus system by Cs-137 has a double purpose: help to quantity the different factors which influence the contamination/decontamination of the algae and to show the influence of the different experimental conditions. A simple model is developed using the conservation equations for the water, the algae biomass and Cs-137. It is supposed that the contamination is an adsorption phenomenon. This model represents satisfactorily the laboratory experiments and explains some curious phenomenons noticed by the experimentators. The model shows that the transfer factor at equilibrium depends on the experimental conditions and this factor does not allow an absolute quantification of the radiocontamination phenomenon. (Author)

  5. Modeling of leachable {sup 137}Cs in throughfall and stemflow for Japanese forest canopies after Fukushima Daiichi Nuclear Power Plant accident

    Energy Technology Data Exchange (ETDEWEB)

    Loffredo, Nicolas, E-mail: wataiso@free.fr [Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572 (Japan); Onda, Yuichi [Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572 (Japan); Kawamori, Ayumi [Graduate School of Life and Environmental Sciences, University of Tsukuba (Japan); Kato, Hiroaki [Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572 (Japan)

    2014-09-15

    The Fukushima accident dispersed significant amounts of radioactive cesium (Cs) in the landscape. Our research investigated, from June 2011 to November 2013, the mobility of leachable Cs in forests canopies. In particular, {sup 137}Cs and {sup 134}Cs activity concentrations were measured in rainfall, throughfall, and stemflow in broad-leaf and cedar forests in an area located 40 km from the power plant. Leachable {sup 137}Cs loss was modeled by a double exponential (DE) model. This model could not reproduce the variation in activity concentration observed. In order to refine the DE model, the main physical measurable parameters (rainfall intensity, wind velocity, and snowfall occurrence) were assessed, and rainfall was identified as the dominant factor controlling observed variation. A corrective factor was then developed to incorporate rainfall intensity in an improved DE model. With the original DE model, we estimated total {sup 137}Cs loss by leaching from canopies to be 72 ± 4%, 67 ± 4%, and 48 ± 2% of the total plume deposition under mature cedar, young cedar, and broad-leaf forests, respectively. In contrast, with the improved DE model, the total {sup 137}Cs loss by leaching was estimated to be 34 ± 2%, 34 ± 2%, and 16 ± 1% of the total plume deposition under mature cedar, young cedar, and broad-leaf forests, respectively. The improved DE model corresponds better to observed data in literature. Understanding {sup 137}Cs and {sup 134}Cs forest dynamics is important for forecasting future contamination of forest soils around the FDNPP. It also provides a basis for understanding forest transfers in future potential nuclear disasters. - Highlights: • A double exponential model was used to model leachable cesium loss from canopies. • The model could not reproduce variation observed. • Rainfall was identified as the dominant factor controlling the variation. • A rainfall parameter was used to develop an improved double exponential model. • The

  6. Colloid-Facilitated Transport of 137Cs in Fracture-Fill Material. Experiments and Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Dittrich, Timothy M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Reimus, Paul William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-10-29

    In this study, we demonstrate how a combination of batch sorption/desorption experiments and column transport experiments were used to effectively parameterize a model describing the colloid-facilitated transport of Cs in the Grimsel granodiorite/FFM system. Cs partition coefficient estimates onto both the colloids and the stationary media obtained from the batch experiments were used as initial estimates of partition coefficients in the column experiments, and then the column experiment results were used to obtain refined estimates of the number of different sorption sites and the adsorption and desorption rate constants of the sites. The desorption portion of the column breakthrough curves highlighted the importance of accounting for adsorption-desorption hysteresis (or a very nonlinear adsorption isotherm) of the Cs on the FFM in the model, and this portion of the breakthrough curves also dictated that there be at least two different types of sorption sites on the FFM. In the end, the two-site model parameters estimated from the column experiments provided excellent matches to the batch adsorption/desorption data, which provided a measure of assurance in the validity of the model.

  7. Modelling of Cs-137 availability in soils subjected to contamination after the accident at the Chernobyl NPP

    International Nuclear Information System (INIS)

    Fesenko, S.V.; Spiridonov, S.I.; Sanzharova, N.I.; Aleksakhin, R.M.

    1996-01-01

    Results of the application of the model describing behaviour of the radionuclide in meadow ecosystems for the analysis of the factors governing of the radionuclide availability in soils are presented. The estimation of characteristics of fuel particles in near zone of the Chernobyl NPP is given. It is shown that in the first period after the accident the main factors determining Cs-137 availability in soil are property of soil and mat as well as fallout characteristics. Refs. 6, figs. 5

  8. A model with charges and polarizability for CS2 in an ionic liquid

    Indian Academy of Sciences (India)

    RUTH M LYNDEN-BELL

    the static electrostatic distribution in the CS2 molecule with 7 charged sites and anisotropic polarizability on the carbon site and isotropic .... the charges modified to reproduce the molecular quad- ... face at 1.5 times the van der Waals radii from the nuclei ..... shows the probability distribution of induced dipoles on the C site ...

  9. Risk adjustment models for interhospital comparison of CS rates using Robson's ten group classification system and other socio-demographic and clinical variables.

    Science.gov (United States)

    Colais, Paola; Fantini, Maria P; Fusco, Danilo; Carretta, Elisa; Stivanello, Elisa; Lenzi, Jacopo; Pieri, Giulia; Perucci, Carlo A

    2012-06-21

    Caesarean section (CS) rate is a quality of health care indicator frequently used at national and international level. The aim of this study was to assess whether adjustment for Robson's Ten Group Classification System (TGCS), and clinical and socio-demographic variables of the mother and the fetus is necessary for inter-hospital comparisons of CS rates. The study population includes 64,423 deliveries in Emilia-Romagna between January 1, 2003 and December 31, 2004, classified according to theTGCS. Poisson regression was used to estimate crude and adjusted hospital relative risks of CS compared to a reference category. Analyses were carried out in the overall population and separately according to the Robson groups (groups I, II, III, IV and V-X combined). Adjusted relative risks (RR) of CS were estimated using two risk-adjustment models; the first (M1) including the TGCS group as the only adjustment factor; the second (M2) including in addition demographic and clinical confounders identified using a stepwise selection procedure. Percentage variations between crude and adjusted RRs by hospital were calculated to evaluate the confounding effect of covariates. The percentage variations from crude to adjusted RR proved to be similar in M1 and M2 model. However, stratified analyses by Robson's classification groups showed that residual confounding for clinical and demographic variables was present in groups I (nulliparous, single, cephalic, ≥37 weeks, spontaneous labour) and III (multiparous, excluding previous CS, single, cephalic, ≥37 weeks, spontaneous labour) and IV (multiparous, excluding previous CS, single, cephalic, ≥37 weeks, induced or CS before labour) and to a minor extent in groups II (nulliparous, single, cephalic, ≥37 weeks, induced or CS before labour) and IV (multiparous, excluding previous CS, single, cephalic, ≥37 weeks, induced or CS before labour). The TGCS classification is useful for inter-hospital comparison of CS section rates, but

  10. Mathematical model to determine the dimensions of superconducting cylindrical coils with a given central field – the case study for MgB{sub 2} conductors with isotropic I{sub c}(B) characteristic

    Energy Technology Data Exchange (ETDEWEB)

    Pitel, Jozef, E-mail: jozef.pitel@savba.sk [Institute of Electrical Engineering, Slovak Academy of Sciences, Dúbravská 9, 841 04 Bratislava (Slovakia); Melišek, Tibor [Institute of Electrical Engineering, Slovak Academy of Sciences, Dúbravská 9, 841 04 Bratislava (Slovakia); Tropeano, Matteo; Nardelli, Davide; Tumino, Andrea [Columbus Superconductors, Via delle Terre Rosse 30, I-16133 Genova (Italy)

    2016-08-15

    Highlights: • Influence of the winding geometry on central field of cylindrical coils is studied. • Procedure to determine dimensions of coils with a given central field is developed. • The model is applied to MgB{sub 2}/Ni/Cu conductors with isotropic I{sub c}(B) characteristic. • Influence of the thickness of stabilizing copper on coil parameters is analyzed. • Optimization with respect to coil operating current and wire length is discussed. - Abstract: In this work, we present a mathematical model which enables to design cylindrical coils with a given central field, made of the superconducting conductor with isotropic I{sub c}(B) characteristic. The model results in a computer code that enables to find out the coil dimensions, and to calculate the coil parameters such as critical current, maximum field in the winding and field non-uniformity on the coil axis. The I{sub c}(B) characteristic of the conductor is represented by the set of data measured in discrete points. This approach allows us to express the I{sub c}(B) as a function linearized in parts. Then, it is possible to involve the central field of the coil, coil dimensions, and parameters of the conductor, including its I{sub c}(B) characteristic, in one equation which can be solved using ordinary numerical non-linear methods. Since the coil dimensions and conductor parameters are mutually linked in one equation with respect to a given coil central field, it is possible to analyze an influence of one parameter on the other one. The model was applied to three commercially available MgB{sub 2}/Ni/Cu conductors produced by Columbus Superconductors. The results of simulations with the I{sub c}(B) data at 20 K illustrate that there exists a set of winding geometries that generate a required central field, changing from a disc shape to long thin solenoid. Further, we analyze how the thickness of stabilizing copper influences the coil dimensions, overall conductor length, coil critical current, maximum

  11. Conception of Brownian coil

    OpenAIRE

    Zhang, Jiayuan

    2018-01-01

    This article proposes a conception of Brownian coil. Brownian coil is a tiny coil with the same size of pollen. Once immersed into designed magnetic field and liquid, the coil will be moved and deformed macroscopically, due to the microscopic thermodynamic molecular collisions. Such deformation and movement will change the magnetic flux through the coil, by which an ElectroMotive Force (EMF) is produced. In this work, Brownian heat exchanger and Brownian generator are further designed to tran...

  12. Behaviour of oceanic 137Cs following the Fukushima Daiichi Nuclear Power Plant accident for four years simulated numerically by a regional ocean model

    Science.gov (United States)

    Tsumune, D.; Tsubono, T.; Aoyama, M.; Misumi, K.; Tateda, Y.

    2015-12-01

    A series of accidents at the Fukushima Dai-ichi Nuclear Power Plant (1F NPP) following the earthquake and tsunami of 11 March 2011 resulted in the release of radioactive materials to the ocean by two major pathways, direct release from the accident site and atmospheric deposition.We reconstructed spatiotemporal variability of 137Cs activity in the regional ocean for four years by numerical model, such as a regional scale and the North Pacific scale oceanic dispersion models, an atmospheric transport model, a sediment transport model, a dynamic biological compartment model for marine biota and river runoff model. Direct release rate of 137Cs were estimated for four years after the accident by comparing simulated results and observed activities very close to the site. The estimated total amounts of directly release was 3.6±0.7 PBq. Directly release rate of 137Cs decreased exponentially with time by the end of December 2012 and then, was almost constant. Decrease rate were quite small after 2013. The daily release rate of 137Cs was estimated to be the order of magnitude of 1010 Bq/day by the end of March 2015. The activity of directly released 137Cs was detectable only in the coastal zone after December 2012. Simulated 137Cs activities attributable to direct release were in good agreement with observed activities, a result that implies the estimated direct release rate was reasonable. There is no observed data of 137Cs activity in the ocean from 11 to 21 March 2011. Observed data of marine biota should reflect the history of 137Cs activity in this early period. We reconstructed the history of 137Cs activity in this early period by considering atmospheric deposition, river input, rain water runoff from the 1F NPP site. The comparisons between simulated 137Cs activity of marine biota by a dynamic biological compartment and observed data also suggest that simulated 137Cs activity attributable to atmospheric deposition was underestimated in this early period. The

  13. ANL experimental program for pulsed superconducting coils

    International Nuclear Information System (INIS)

    Wang, S.T.; Kim, S.H.; Praeg, W.F.; Krieger, C.I.

    1978-01-01

    Argonne National Laboratory (ANL) had recognized the clear advantage of a superconducting ohmic-heating (OH) coil and started in aggressive development program in FY 1977. The main objectives for FY 1977 are to develop cryostable basic cable configurations with reasonably low ac losses, to develop 12 kA cryostable cable, using it to design and build a 1.5 MJ pulsed coil, and to develop a rather inexpensive large fiberglass reinforced helium cryostat for the 1.5 MJ pulsed coil. The principal objective in building the 1.5 MJ ac coil is to demonstrate ac cryostability of a large coil ranging from 2 T/s up to 12 T/s. Another objective in the pulsed coil program is to determine the feasibility of parallel coil operation in order to avoid excessive voltage and current requirements and to minimize the number of turns for the equilibrium field (EF) coils, should the EF coils be connected in parallel with the OH coils. A two-coil section model using the 11 kA cable will be built and tested

  14. ANL experimental program for pulsed superconducting coils

    International Nuclear Information System (INIS)

    Wang, S.T.; Kim, S.H.; Praeg, W.F.; Krieger, C.I.

    1977-01-01

    Argonne National Laboratory (ANL) had recognized the clear advantage of a superconducting ohmic-heating (OH) coil and started an aggressive development program in FY 1977. The main objectives for FY 1977 are to develop cryostable basic cable configurations with reasonably low ac losses, to develop 12 kA cryostable cable, using it to design and build a 1.5 MJ pulsed coil, and to develop a rather inexpensive large fiberglass reinforced helium cryostat for the 1.5 MJ pulsed coil. The principal objective in building the 1.5 MJ ac coil is to demonstrate ac cryostability of a large coil ranging from 2 T/s up to 12 T/s. Another objective in the pusled coil program is to determine the feasibility of parallel coil operation in order to avoid excessive voltage and current requirements and to minimize the number of turns for the equilibrium field (EF) coils, should the EF coils be connected in parallel with the OH coils. A two-coil section model using the 11 kA cable will be built and tested

  15. Comparison of 137Cs fallout redistribution analysis and conventional erosion-prediction models (WEPP, USLE)

    International Nuclear Information System (INIS)

    Sparovek, G.; Bacchi, O.O.S.; Ranieri, S.B.L.; Schnug, E.; De-Maria, I.C.

    2002-01-01

    Soil erosion is the most important component of the degradation of tropical agroecosystems. The rates of erosion should be considered in land evaluation and conservation planning assessment. The methods available for erosion prediction are not sufficiently well calibrated or validated for tropical soils, climates and crops. Thus, differences in estimated soil-erosion values may be expected, even if considering a single set of input data. Three methods for the estimation of soil erosion (USLE, WEPP, and 137 Cs) were applied to a watershed cultivated with sugarcane in southeastern Brazil. The absolute erosion-rate values and differences in the spatial distribution were evaluated. The overall results suggest important differences in the estimates obtained by the three methods. The differences occurred both in mean values and in geographic locations. The relative mean values for soil loss were USLE>> 137 Cs>WEPP and for standard deviations were USLE>WEPP> 137 Cs, indicating that USLE predicted the highest erosion values spread out over the widest range. The poor geographical coincidence of the results is evidence that values resulting from non-calibrated erosion methods should be considered only as qualitative indications. The method selection should consider overall site variability in relation to factors to which the methods are known to be sensitive. (author)

  16. Predicting the uptake of Cs, Co, Ni, Eu, Th and U on argillaceous rocks using sorption models for illite

    International Nuclear Information System (INIS)

    Marques Fernandes, Maria; Vér, Nóra; Baeyens, Bart

    2015-01-01

    Highlights: • Contaminant retention in argillaceous rocks controlled by sorption on clay minerals. • Cs, Ni, Co, Eu, Th and UO 2 sorption isotherm measurements on Boda and Opalinus Clay. • Boda and Opalinus Clay exhibit different mineralogies and porewater compositions. • Blind predictions using quasi-mechanistic sorption models developed for illite. • Good agreement between measurements and blind predictions. - Abstract: Reliable predictions of radiocontaminant migration are a requirement for the establishment of radioactive waste repositories. Parametrization of the necessary sorption models seems to be, however, extremely challenging given the multi-mineralic composition of the lithosphere. In this study it is shown for two argillaceous rocks – Boda and Opalinus Clay relevant for the Hungarian and Swiss repository concepts, respectively – that this task can be substantially simplified by taking into account only the most sorptive mineral fraction, namely the 2:1 clay minerals illite and illite/smectite mixed layers. Two different models were required to blind predict the sorption isotherms of Cs, Co, Ni, Eu, Th and UO 2 measured on the two clay rock samples in a synthetic porewater. Cs sorption was modelled with the generalised Cs (GCs) sorption model and the sorption of the other cations with the 2site protolysis non electrostatic surface complexation and cation exchange (2SPNE SC/CE) model. The 2SPNE SC/CE model for illite was extended with surface complexation reactions on weak sites for Co, Ni, Eu, UO 2 and on strong sites for Eu-carbonato complexes. Complementary to the sorption measurements and modelling, extended X-ray absorption fine structure (EXAFS) spectroscopy was used to probe the retention mechanism of Ni on illite, Boda and Opalinus Clay at higher loadings. The reliable blind predictions of the selected metal cations, which are representative for monovalent alkaline metals, divalent transition metals, lanthanides, and trivalent

  17. Three-axis orthogonal transceiver coil for eddy current sounding

    Science.gov (United States)

    Sukhanov, D.; Zavyalova, K.; Goncharik, M.

    2017-08-01

    We propose the new structure of three-axis transceiver magnetic-induction coil for eddy current probing. Due to the orientation of the coils, the direct signal from the transmitting coil to the receiving coil is minimized, which provided a high dynamic range. Sensitivity in all directions is provided by combining coils of different orientations. Numerical simulation and experimental studies of such a system have been carried out and confirmed the applicability of the proposed method and the mathematical model.

  18. Multicoil2: predicting coiled coils and their oligomerization states from sequence in the twilight zone.

    Directory of Open Access Journals (Sweden)

    Jason Trigg

    Full Text Available The alpha-helical coiled coil can adopt a variety of topologies, among the most common of which are parallel and antiparallel dimers and trimers. We present Multicoil2, an algorithm that predicts both the location and oligomerization state (two versus three helices of coiled coils in protein sequences. Multicoil2 combines the pairwise correlations of the previous Multicoil method with the flexibility of Hidden Markov Models (HMMs in a Markov Random Field (MRF. The resulting algorithm integrates sequence features, including pairwise interactions, through multinomial logistic regression to devise an optimized scoring function for distinguishing dimer, trimer and non-coiled-coil oligomerization states; this scoring function is used to produce Markov Random Field potentials that incorporate pairwise correlations localized in sequence. Multicoil2 significantly improves both coiled-coil detection and dimer versus trimer state prediction over the original Multicoil algorithm retrained on a newly-constructed database of coiled-coil sequences. The new database, comprised of 2,105 sequences containing 124,088 residues, includes reliable structural annotations based on experimental data in the literature. Notably, the enhanced performance of Multicoil2 is evident when tested in stringent leave-family-out cross-validation on the new database, reflecting expected performance on challenging new prediction targets that have minimal sequence similarity to known coiled-coil families. The Multicoil2 program and training database are available for download from http://multicoil2.csail.mit.edu.

  19. Soil erosion evaluation in a small watershed in Brazil through 137Cs fallout redistribution analysis and conventional models

    International Nuclear Information System (INIS)

    Bacchi, O.O.S.; Reichard, K.; Sparovek, G.; Ranieri, S.B.L.

    2000-01-01

    An investigation of rates and patterns of soil erosion on agricultural land cultivated with sugarcane was undertaken using the 137 Cs technique, USLE (Universal Soil Loss Equation) and WEPP (Water Erosion Prediction Project) model. The study was carried out on a representative catchment of a small watershed of the Piracicaba river basin, State of Sao Paulo, Brazil, called Ceveiro watershed, well known for its severe soil degradation caused by erosion. The results from the 137 Cs technique indicate that most part of the studied area (94%) are eroded at erosion rates that go up to 59 Mg ha -1 y -1 , with a weighted average rate of 23 Mg ha -1 y -1 . The weighted average rate of infield deposition and sediment retrieval that occurs in only 6% of the total area was estimated to be around 12 Mg ha -1 y -1 . These values led to very high net soil loss from the field, with rates of the order of 21 Mg ha -1 y -1 , which represents a sediment delivery ratio of 97%. A linear correlation between soil erosion rate estimated by the 137 Cs technique and the amount of available K in the top soil layer (0-20 cm) was observed. Based on this correlation the estimated amounts of net and gross K loss in the grid area due to soil erosion were of 0.2 and 1.52 kg ha -1 y -1 , respectively. The erosion rate estimated by USLE was 39 Mg ha -1 y -1 and by WEPP model 16.5 Mg ha -1 y -1 with a sediment delivery of 12.4 Mg ha -1 y -1 (75%). The results are a confirmation that the soil conservation practices adopted in the area are very poor and can explain the high siltation level of water reservoirs in the watershed. (author) [pt

  20. Recent sedimentation rates in the Caravelas estuary (Bahia, Brazil) using unsupported 210Pb and 137Cs modeling

    International Nuclear Information System (INIS)

    Friedmann Angeli, Jose Lourenco; Alves de Lima Ferreira, Paulo; Lopes Figueira, Rubens Cesar; Venturini, Natalia; Univ. of la Republica, Montevideo

    2016-01-01

    The Caravelas estuary is located in a zone of the Brazilian coast (Southern Bahia State) which has been submitted to different kinds of land uses during the last 50 years. This zone has an important ecological role, due to its mangroves and its location next to Abrolhos coral reef, the most important in the Southern Atlantic Ocean. 210 Pb and 137 Cs dating methods, accompanied by a sedimentological study, were applied to sediment cores in order to establish sedimentation rates and identify historical trends of land use and erosive processes. Sedimentation rates were established according to the ''Constant Rate of Supply'' (CRS) 210 Pb dating model, which was preferred rather than the ''Constant Initial Concentration'' (CIC) model. Corrected sedimentation rates obtained from 210 Pb dating were corroborated through a second independent radionuclide tracer such as 137 Cs. The sedimentation rates obtained according to the CRS model for the cores were 1.07 ± 0.13 cm yr -1 for T2 (inner sector), 0.65 ± 0.06 cm yr -1 for T5 and 0.85 ± 0.09 cm yr -1 for T8 (outer sector). The difference in sedimentation rates among the sampling sites could be due to hydrodynamic processes and could be related to the tendency of increase of erosive processes, conditioned by the changes in the landscape and land use to, which this region has been submitted.

  1. Local SAR in High Pass Birdcage and TEM Body Coils for Multiple Human Body Models in Clinical Landmark Positions at 3T

    Science.gov (United States)

    Yeo, Desmond TB; Wang, Zhangwei; Loew, Wolfgang; Vogel, Mika W; Hancu, Ileana

    2011-01-01

    Purpose To use EM simulations to study the effects of body type, landmark position, and RF body coil type on peak local SAR in 3T MRI. Materials and Methods Numerically computed peak local SAR for four human body models (HBMs) in three landmark positions (head, heart, pelvic) were compared for a high-pass birdcage and a transverse electromagnetic 3T body coil. Local SAR values were normalized to the IEC whole-body average SAR limit of 2.0 W/kg for normal scan mode. Results Local SAR distributions were highly variable. Consistent with previous reports, the peak local SAR values generally occurred in the neck-shoulder area, near rungs, or between tissues of greatly differing electrical properties. The HBM type significantly influenced the peak local SAR, with stockier HBMs, extending extremities towards rungs, displaying the highest SAR. There was also a trend for higher peak SAR in the head-centric and heart-centric positions. The impact of the coil-types studied was not statistically significant. Conclusion The large variability in peak local SAR indicates the need to include more than one HBM or landmark position when evaluating safety of body coils. It is recommended that a HBM with arms near the rungs be included, to create physically realizable high-SAR scenarios. PMID:21509880

  2. Analysis of the local worst-case SAR exposure caused by an MRI multi-transmit body coil in anatomical models of the human body

    International Nuclear Information System (INIS)

    Neufeld, Esra; Gosselin, Marie-Christine; Murbach, Manuel; Christ, Andreas; Cabot, Eugenia; Kuster, Niels

    2011-01-01

    Multi-transmit coils are increasingly being employed in high-field magnetic resonance imaging, along with a growing interest in multi-transmit body coils. However, they can lead to an increase in whole-body and local specific absorption rate (SAR) compared to conventional body coils excited in circular polarization for the same total incident input power. In this study, the maximum increase of SAR for three significantly different human anatomies is investigated for a large 3 T (128 MHz) multi-transmit body coil using numerical simulations and a (generalized) eigenvalue-based approach. The results demonstrate that the increase of SAR strongly depends on the anatomy. For the three models and normalization to the sum of the rung currents squared, the whole-body averaged SAR increases by up to a factor of 1.6 compared to conventional excitation and the peak spatial SAR (averaged over any 10 cm 3 of tissue) by up to 13.4. For some locations the local averaged SAR goes up as much as 800 times (130 when looking only at regions where it is above 1% of the peak spatial SAR). The ratio of the peak spatial SAR to the whole-body SAR increases by a factor of up to 47 and can reach values above 800. Due to the potentially much larger power deposition, additional, preferably patient-specific, considerations are necessary to avoid injuries by such systems.

  3. Analysis of the local worst-case SAR exposure caused by an MRI multi-transmit body coil in anatomical models of the human body

    Energy Technology Data Exchange (ETDEWEB)

    Neufeld, Esra; Gosselin, Marie-Christine; Murbach, Manuel; Christ, Andreas; Cabot, Eugenia; Kuster, Niels, E-mail: neufeld@itis.ethz.ch [Foundation for Research on Information Technologies in Society (IT' IS), Zeughausstr. 43, 8004 Zuerich (Switzerland)

    2011-08-07

    Multi-transmit coils are increasingly being employed in high-field magnetic resonance imaging, along with a growing interest in multi-transmit body coils. However, they can lead to an increase in whole-body and local specific absorption rate (SAR) compared to conventional body coils excited in circular polarization for the same total incident input power. In this study, the maximum increase of SAR for three significantly different human anatomies is investigated for a large 3 T (128 MHz) multi-transmit body coil using numerical simulations and a (generalized) eigenvalue-based approach. The results demonstrate that the increase of SAR strongly depends on the anatomy. For the three models and normalization to the sum of the rung currents squared, the whole-body averaged SAR increases by up to a factor of 1.6 compared to conventional excitation and the peak spatial SAR (averaged over any 10 cm{sup 3} of tissue) by up to 13.4. For some locations the local averaged SAR goes up as much as 800 times (130 when looking only at regions where it is above 1% of the peak spatial SAR). The ratio of the peak spatial SAR to the whole-body SAR increases by a factor of up to 47 and can reach values above 800. Due to the potentially much larger power deposition, additional, preferably patient-specific, considerations are necessary to avoid injuries by such systems.

  4. Precision comparison of the erosion rates derived from 137Cs measurements models with predictions based on empirical relationship

    International Nuclear Information System (INIS)

    Yang Mingyi; Liu Puling; Li Liqing

    2004-01-01

    The soil samples were collected in 6 cultivated runoff plots with grid sampling method, and the soil erosion rates derived from 137 Cs measurements were calculated. The models precision of Zhang Xinbao, Zhou Weizhi, Yang Hao and Walling were compared with predictions based on empirical relationship, data showed that the precision of 4 models is high within 50m slope length except for the slope with low slope angle and short length. Relatively, the precision of Walling's model is better than that of Zhang Xinbao, Zhou Weizhi and Yang Hao. In addition, the relationship between parameter Γ in Walling's improved model and slope angle was analyzed, the ralation is: Y=0.0109 X 1.0072 . (authors)

  5. Water cooling coil

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, S; Ito, Y; Kazawa, Y

    1975-02-05

    Object: To provide a water cooling coil in a toroidal nuclear fusion device, in which coil is formed into a small-size in section so as not to increase dimensions, weight or the like of machineries including the coil. Structure: A conductor arranged as an outermost layer of a multiple-wind water cooling coil comprises a hollow conductor, which is directly cooled by fluid, and as a consequence, a solid conductor disposed interiorly thereof is cooled indirectly.

  6. Exploring the limits of a very large Nb3Sn conductor: the 80 kA conductor of the ITER toroidal field model coil

    International Nuclear Information System (INIS)

    Duchateau, J.L.; Ciazynski, D.; Guerber, O.; Park, S.H.; Zani, L.

    2003-01-01

    In Phase II experiment of the International Thermonuclear Experimental Reactor (ITER) Toroidal Field Model Coil (TFMC) the operation limits of its 80 kA Nb 3 Sn conductor were explored. To increase the magnetic field on the conductor, the TFMC was tested in presence of another large coil: the EURATOM-LCT coil. Under these conditions the maximum field reached on the conductor, was around 10 tesla. This exploration has been performed at constant current, by progressively increasing the coil temperature and monitoring the coil voltage drop in the current sharing regime. Such an operation was made possible thanks to the very high stability of the conductor. The aim of these tests was to compare the critical properties of the conductor with expectations and assess the ITER TF conductor design. These expectations are based on the documented critical field and temperature dependent properties of the 720 superconducting strands which compose the conductor. In addition the conductor properties are highly dependent on the strain, due to the compression appearing on Nb 3 Sn during the heat treatment of the pancakes and related to the differential thermal compression between Nb 3 Sn and the stainless steel jacket. No precise model exists to predict this strain, which is therefore the main information, which is expected from these tests. The method to deduce this strain from the different tests is presented, including a thermalhydraulic analysis to identify the temperature of the critical point and a careful estimation of the field map across the conductor. The measured strain has been estimated in the range -0.75% to -0.79 %. This information will be taken into account for ITER design and some adjustment of the ITER conductor design is under examination. (authors)

  7. A new modeling procedure for circuit design and performance prediction of evaporator coils using CO2 as refrigerant

    International Nuclear Information System (INIS)

    Larbi Bendaoud, Adlane; Ouzzane, Mohamed; Aidoun, Zine; Galanis, Nicolas

    2010-01-01

    The replacement of environmentally damaging synthetic refrigerants due to their ODP or GWI potential by natural refrigerants such as CO 2 is now up in the research agenda. Moreover, current energy supply concerns make of efficiency another first priority issue to dictate new stringent design criteria for industrial and commercial equipment. Heat exchangers are the most important components in refrigeration systems where they are used as evaporators or condensers and their design and operation have a considerable impact on overall system performance. Hence, it is important to better understand their thermal and hydrodynamic behaviour in order to improve their design and operation. Numerical simulation represents a very efficient tool for achieving this objective. In this paper, a new modeling approach, accounting for the heat transfer the hydrodynamics of the problem and intended to predict the dynamic behaviour of a refrigeration coil under dry conditions is proposed. A related FORTRAN program was developed, allowing the study of a large range of complex refrigerant circuit configurations. The equations describing these aspects are strongly coupled, and their decoupling is reached by using an original method of resolution. Circuits may have several inlets, outlets, bifurcations and feed one or several other tubes inlets. The coil was subdivided into several elementary control volumes and its analysis provided detailed information in X, Y and Z directions. Validation was performed with data from a CO 2 secondary refrigeration loop test bench built in CanmetENERGY Laboratories. These data were predicted satisfactorily over the operating range corresponding to refrigeration applications. Exemplary simulations were then performed on an evaporator typically employed in supermarkets, showing the effect of circuiting on operation and performance. Even though circuiting is common practice in refrigeration this simulation shows that care must be exercised in making the

  8. Test facility for PLT TF coils

    International Nuclear Information System (INIS)

    Hearney, J.; File, J.; Dreskin, S.

    1975-01-01

    Past experience with the model C stellerator and other toroidal field devices indicates that mechanical and electrical tests of a toroidal field coil prior to maximum field operation of the device is prudent and desirable. This paper describes a test program for the PLT-TF coils. The test stand consists of one test coil, two background coils and a steel supporting structure. The three coil configuration produces a 67.5 kG field at the inner conductor (38 kG at the bore center) and simulates a 1/R field distribution in the bore of the test coil. The resolution of the field force system and resultant stresses within the test structure are discussed. A test procedure is described which maximizes the information obtained from a 100,000 pulse program

  9. Outcomes with single-coil versus dual-coil implantable cardioverter defibrillators: a meta-analysis.

    Science.gov (United States)

    Sunderland, Nicholas; Kaura, Amit; Murgatroyd, Francis; Dhillon, Para; Scott, Paul A

    2018-03-01

    Dual-coil implantable cardioverter defibrillator (ICD) leads have traditionally been used over single-coil leads due to concerns regarding high defibrillation thresholds (DFT) and consequent poor shock efficacy. However, accumulating evidence suggests that this position may be unfounded and that dual-coil leads may also be associated with higher complication rates during lead extraction. This meta-analysis collates data comparing dual- and single-coil ICD leads. Electronic databases were systematically searched for randomized controlled trials (RCT) and non-randomized studies comparing single-coil and dual-coil leads. The mean differences in DFT and summary estimates of the odds-ratio (OR) for first-shock efficacy and the hazard-ratio (HR) for all-cause mortality were calculated using random effects models. Eighteen studies including a total of 138,124 patients were identified. Dual-coil leads were associated with a lower DFT compared to single coil leads (mean difference -0.83J; 95% confidence interval [CI] -1.39--0.27; P = 0.004). There was no difference in the first-shock success rate with dual-coil compared to single-coil leads (OR 0.74; 95%CI 0.45-1.21; P=0.22). There was a significantly lower risk of all-cause mortality associated with single-coil leads (HR 0.91; 95%CI 0.86-0.95; P dual-coil leads. The mortality benefit with single-coil leads most likely represents patient selection bias. Given the increased risk and complexity of extracting dual-coil leads, centres should strongly consider single-coil ICD leads as the lead of choice for routine new left-sided ICD implants. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

  10. Atmospheric Dispersion Modeling of 137Cs generated from Nuclear Spent Fuel under Hypothetic Accidental Condition in the BNPP Area

    Science.gov (United States)

    Lee, Jongkuk; Lee, Kwan-Hee; Yook, Daesik; Kim, Sung Il; Lee, Byung Soo

    2016-04-01

    This study presents the results of atmosphere dispersion modeling using CALPUFF code that are based on computational simulation to evaluate the environmental characteristics of the Barakah nuclear power plant (BNPP) in west area of UAE. According to meteorological data analysis (2012~2013), the winds from the north(7.68%) and west(9.05%) including NNW(41.63%), NW(28.55%), and WNW(6.31%) winds accounted for more than 90% of the wind directions. East(0.2%) and south(0.6%) direction wind, including ESE(0.31%), SE(0.38%), and SSE(0.38%) were rarely distributed during the simulation period. Seasonal effects were not showed. However, a discrepancy in the tendency between daytime and night-time was observed. Approximately 87% of the wind speed was distributed below 5.4m/s (17%, 47% and 23% between the speeds of 0.5-1.8m/s 1.8-3.3m/s and 3.3-5.4m/s, respectively) during the annual period. Seasonal wind speed distribution results presented very similar pattern of annual distribution. Wind speed distribution of day and night, on the other hand, had a discrepancy with annual modeling results than seasonal distribution in some sections. The results for high wind speed (more than 10.8m/s) showed that this wind blew from the west. This high wind speed is known locally as the 'Shamal', which occurs rarely, lasting one or two days with the strongest winds experienced in association with gust fronts and thunderstorms. Six variations of cesium-137 (137Cs) dispersion test were simulated under hypothetic severe accidental condition. The 137Cs dispersion was strongly influenced by the direction and speed of the main wind. From the test cases, east-south area of the BNPP site was mainly influenced by 137Cs dispersion. A virtual receptor was set and calculated for observation of the 137Cs movement and accumulation. Surface roughness tests were performed for the analysis of topographic conditions. According to the surface condition, there are various surface roughness length. Four types

  11. Optimization of the ECT background coil

    International Nuclear Information System (INIS)

    Ballou, J.K.; Luton, J.N.

    1975-01-01

    This study was begun to optimize the Eccentric Coil Test (ECT) background coil. In the course of this work a general optimization code was obtained, tested, and applied to the ECT problem. So far this code has proven to be very satisfactory. The results obtained with this code and earlier codes have illustrated the parametric behavior of such a coil system and that the optimum for this type system is broad. This study also shows that a background coil with a winding current density of less than 3000 A/cm 2 is not feasible for the ECT models presented in this paper

  12. A continuous winding scheme for superconducting tokamak coils with cable-in-conduit conductor

    International Nuclear Information System (INIS)

    Kim, Sang-ho; Chung, Kie-hyung; Lee, Deok Kyo

    2001-01-01

    Superconducting magnet coils are essential for steady-state or long-pulse operation of tokamaks. In an advanced tokamak, the central solenoid (CS) coils are usually divided into several pairs of modules to provide for an extra plasma shaping capability in addition to those available from the shaping (poloidal field) coils. In the conventional pancake winding scheme of superconducting coils, each coil consists of separate superconducting 'double-pancake' coils connected together in series; however, such joints are not superconducting, which is one of the major disadvantages, especially in pulsed operations. A new type of winding was adopted for the ITER CS coil, which consists of cylindrical shell 'layers' joined in series. A disadvantage of this layer winding is its inability to yield modular coils that can provide certain degree of plasma shaping. Joints can be removed in a coil winding pack with the conventional pancake winding scheme, if the conductor is sufficiently long and the winding machine is properly equipped. The compactness, however, cannot be preserved with this scheme. The winding compactness is important since the radial build of the CS coils is one of the major parameters that determine the machine size. In this paper, we present a continuous winding scheme that requires no joints, allows coil fabrication at minimum dimension, and meets the flux swing requirement and other practical aspects

  13. A model for calculating the AC losses of second-generation high temperature superconductor pancake coils

    Energy Technology Data Exchange (ETDEWEB)

    Yuan Weijia; Campbell, A M; Coombs, T A [Electronic, Power and Energy Conversion Group, Engineering Department, University of Cambridge, Cambridge CB2 1PZ (United Kingdom)], E-mail: wy215@cam.ac.uk

    2009-07-15

    A model is presented for calculating the AC losses of a stack of second-generation high temperature superconductor tapes. This model takes as a starting point the model of Clem and co-workers for a stack in which each tape carries the same current. It is based on the assumption that the magnetic flux lines lie parallel to the tapes within the part of the stack where the flux has not penetrated. In this paper we allow for the depth of penetration of field to vary across the stack, and use the Kim model to allow for the variation of J{sub c} with B. The model is applied to the cases of a transport current and an applied field. For a transport current the calculated result differs from the Norris expression for a single tape carrying a uniform current and it does not seem possible to define a suitable average J{sub c} which could be used. Our method also gives a more accurate value for the critical current of the stack than other methods. For an applied field the stack behaves as a solid superconductor with the J{sub c} averaged locally over several tapes, but still allowed to vary throughout the stack on a larger scale. For up to about ten tapes the losses rise rapidly with the number of tapes, but in thicker stacks the tapes shield each other and the losses become that of a slab with a field parallel to the faces.

  14. Dual coil ignition system

    Energy Technology Data Exchange (ETDEWEB)

    Huberts, Garlan J.; Qu, Qiuping; Czekala, Michael Damian

    2017-03-28

    A dual coil ignition system is provided. The dual coil ignition system includes a first inductive ignition coil including a first primary winding and a first secondary winding, and a second inductive ignition coil including a second primary winding and a second secondary winding, the second secondary winding connected in series to the first secondary winding. The dual coil ignition system further includes a diode network including a first diode and a second diode connected between the first secondary winding and the second secondary winding.

  15. A three-dimensional stochastic model of the behavior of radionuclides in forests. Part 2. Cs-137 behavior in forest soils

    International Nuclear Information System (INIS)

    Berg, Mitchell T.; Shuman, Larry J.

    1995-01-01

    Using a three-dimensional stochastic model of radionuclides in forests developed in Part 1, this work simulates the long-term behavior of Cs-137 in forest soil. It is assumed that the behavior of Cs-137 in soils is driven by its advection and dispersion due to the infiltration of the soil solution, and its sorption to the soil matrix. As Cs-137 transport through soils is affected by its uptake and release by forest vegetation, a model of radiocesium behavior in forest vegetation is presented in Part 3 of this paper. To estimate the rate of infiltration of water through the soil, models are presented to estimate the hydrological cycle of the forest including infiltration, evapotranspiration, and the root uptake of water. The state transition probabilities for the random walk model of Cs-137 transport are then estimated using the models developed to predict the distribution of water in the forest. The random walk model is then tested using a base line scenario in which Cs-137 is deposited into a coniferous forest ecosystem

  16. Routine phasing of coiled-coil protein crystal structures with AMPLE

    Directory of Open Access Journals (Sweden)

    Jens M. H. Thomas

    2015-03-01

    Full Text Available Coiled-coil protein folds are among the most abundant in nature. These folds consist of long wound α-helices and are architecturally simple, but paradoxically their crystallographic structures are notoriously difficult to solve with molecular-replacement techniques. The program AMPLE can solve crystal structures by molecular replacement using ab initio search models in the absence of an existent homologous protein structure. AMPLE has been benchmarked on a large and diverse test set of coiled-coil crystal structures and has been found to solve 80% of all cases. Successes included structures with chain lengths of up to 253 residues and resolutions down to 2.9 Å, considerably extending the limits on size and resolution that are typically tractable by ab initio methodologies. The structures of two macromolecular complexes, one including DNA, were also successfully solved using their coiled-coil components. It is demonstrated that both the ab initio modelling and the use of ensemble search models contribute to the success of AMPLE by comparison with phasing attempts using single structures or ideal polyalanine helices. These successes suggest that molecular replacement with AMPLE should be the method of choice for the crystallographic elucidation of a coiled-coil structure. Furthermore, AMPLE may be able to exploit the presence of a coiled coil in a complex to provide a convenient route for phasing.

  17. To the predicted calculations of Cs-137 and Sr-90 migration in soil in the frame of the compartment model

    International Nuclear Information System (INIS)

    Knat'ko, B.A.; Skomorokhov, A.G.

    1994-01-01

    The method of calculation of migration of radionuclides in soil according to compartment model and based on analitical solution of the system of differential equations of the model is proposed. Calculations of the content of radionuclides in the soil layer for Cs-137 and Sr-90 for four types of soil for the periods of 0, 21, 34,46 and 73 months are carried out. Calculations were done for three upper soil layers 0-2.5, 2.5-5, 5.0-15.0 cm, which give the main contribution into transport of radionuclides into plants on meadows and pastures. Such method increases precision of calculations of cesium-137 and strontium-90 migration in comparison with the prosedure, which uses the system of finite difference equations. 6 refs., 1 fig

  18. Biomaterials Made from Coiled-Coil Peptides.

    Science.gov (United States)

    Conticello, Vincent; Hughes, Spencer; Modlin, Charles

    The development of biomaterials designed for specific applications is an important objective in personalized medicine. While the breadth and prominence of biomaterials have increased exponentially over the past decades, critical challenges remain to be addressed, particularly in the development of biomaterials that exhibit highly specific functions. These functional properties are often encoded within the molecular structure of the component molecules. Proteins, as a consequence of their structural specificity, represent useful substrates for the construction of functional biomaterials through rational design. This chapter provides an in-depth survey of biomaterials constructed from coiled-coils, one of the best-understood protein structural motifs. We discuss the utility of this structurally diverse and functionally tunable class of proteins for the creation of novel biomaterials. This discussion illustrates the progress that has been made in the development of coiled-coil biomaterials by showcasing studies that bridge the gap between the academic science and potential technological impact.

  19. Evaluation of inductive heating energy of a PF insert coil conductor by the calorimetric method (Contract research)

    International Nuclear Information System (INIS)

    Matsui, Kunihiro; Nabara, Yoshihiro; Nunoya, Yoshihiko; Koizumi, Norikiyo; Okuno, Kiyoshi

    2009-02-01

    The PF Insert Coil is a single layer solenoid coil using a superconducting conductor designed for ITER, housed in a Poloidal field coil and installed in the bore of the CS Model Coil. A stability test of the conductor will be performed in a magnetic field generated by the CS Model Coil. In this test, the inductive heat of an inductive heater attached to the conductor will be applied to initiate a normal zone in the conductor. Since the conductor for the PF Insert Coil is a cable-in-conduit conductor, it is quite difficult to estimate inductive heating energy theoretically. Thus, the inductive heating energy is measured experimentally by the calorimetric method. The heating energy is in proportion to a constant multiplied by the integrated square of an applied sinusoidal current wave over the heating period. Experimental results show that the proportional constants of the conductor, cable, conduit and dummy conductor are 0.138 [J/A 2 s], 0.028 [J/A 2 s], 0.118 [J/A 2 s] and 0.009 [J/A 2 s], respectively. The first three denote not only the inductive heating but also the joule heating of the inductive heater. The final value denotes joule heating only. Therefore, subtracting the first three constants by the last one, the proportional constants of inductive heating generated in the conductor, cable and conduit are estimated to be 0.129 [J/A 2 s], 0.019 [J/A 2 s] and 0.109 [J/A 2 s], respectively. (author)

  20. The graduate tracking and attainment model at the University of Pécs

    Directory of Open Access Journals (Sweden)

    NORBERT SIPOS

    2013-12-01

    Full Text Available The aim of this study is to provide an overview of the Hungarian higher education system facing changes since 1990. The three major challenges are: the decreasing number of students enrolling since the ‘golden age’ ended; the Bologna-Process and its influence since its introduction in 2006 and the uncertainty about the future role of the state in educational finance. The institutions have to take these changes and the effects on their situation into account and they need to find a way to benefit from them. Thanks to Graduate Follow-Up System (GFS research, they can measure the new graduates performance on the labour-market, their job-related satisfaction levels and possibilities, and furthermore they can have direct information about employers’ expectations, first of all on the level of working skills. This information can be used for the creation of a different approach of how to think about the students and which services could be offered to them. In the following analysis we use data from research conducted in the last three years at the University of Pécs. The focused energy and resource investment is more effective if it is based on specific training and education packages offered within the Alumni framework. It can increase the results of an even more successful Alma Mater service; furthermore it can improve the self-identification of the institution, therefore it is important to have a long-term strategy.

  1. Motional properties of unfolded ubiquitin: a model for a random coil protein

    Energy Technology Data Exchange (ETDEWEB)

    Wirmer, Julia [Johann Wolfgang GoeUniversityFrankfurt, Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (Germany); Peti, Wolfgang [Brown University, Department of Molecular Pharmacology, Physiology and Biotechnology (United States); Schwalbe, Harald [Johann Wolfgang GoeUniversityFrankfurt, Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (Germany)], E-mail: schwalbe@nmr.uni-frankfurt.de

    2006-07-15

    The characterization of unfolded states of proteins has recently attracted considerable interest, as the residual structure present in these states may play a crucial role in determining their folding and misfolding behavior. Here, we investigated the dynamics in the denatured state of ubiquitin in 8 M urea at pH2. Under these conditions, ubiquitin does not have any detectable local residual structure, and uniform {sup 15}N relaxation rates along the sequence indicate the absence of motional restrictions caused by residual secondary structure and/or long-range interactions. A comparison of different models to predict relaxation data in unfolded proteins suggests that the subnanosecond dynamics in unfolded states depend on segmental motions only and do not show a dependence on the residue type but for proline and glycine residues.

  2. Study of electric phenomena in energy dumping of LCT coil

    International Nuclear Information System (INIS)

    Oka, Koichi; Tsuji, Hiroshi; Nishi, Masataka; Shimamoto, Susumu

    1980-03-01

    In IEA-LCT coil, electric phenomena in energy dumping were studied analytically and experimentally. Protection resistance of the Japanese LCT coil is chosen as 0.1 Ω considering the quenching voltage, so that temperature rise of the coil is no problem. Energy dumping characteristic of the six-coil system is calculated under different conditions. It is concluded that simultaneous dumping of all the coils with the equivalent resistance values of protection is necessary. Flashover voltage tests of the model in 4.2 K liquid helium, 4.2 K gas helium and 4.2 K boiling helium show margin in practical quenching voltage of the coil. (author)

  3. Examining the Self-Assembly of Rod-Coil Block Copolymers via Physics Based Polymer Models and Polarized X-Ray Scattering

    Science.gov (United States)

    Hannon, Adam; Sunday, Daniel; Windover, Donald; Liman, Christopher; Bowen, Alec; Khaira, Gurdaman; de Pablo, Juan; Delongchamp, Dean; Kline, R. Joseph

    Photovoltaics, flexible electronics, and stimuli-responsive materials all require enhanced methodology to examine their nanoscale molecular orientation. The mechanical, electronic, optical, and transport properties of devices made from these materials are all a function of this orientation. The polymer chains in these materials are best modeled as semi-flexible to rigid rods. Characterizing the rigidity and molecular orientation of these polymers non-invasively is currently being pursued by using polarized resonant soft X-ray scattering (P-RSoXS). In this presentation, we show recent work on implementing such a characterization process using a rod-coil block copolymer system in the rigid-rod limit. We first demonstrate how we have used physics based models such as self-consistent field theory (SCFT) in non-polarized RSoXS work to fit scattering profiles for thin film coil-coil PS- b-PMMA block copolymer systems. We then show by using a wormlike chain partition function in the SCFT formulism to model the rigid-rod block, the methodology can be used there as well to extract the molecular orientation of the rod block from a simulated P-RSoXS experiment. The results from the work show the potential of the technique to extract thermodynamic and morphological sample information.

  4. Estimation of Cs-137 hillslope patterns of Polesje landscapes using geo-information modeling techniques (on example of the Bryansk region)

    Science.gov (United States)

    Linnik, Vitaly; Nenko, Kristina; Sokolov, Alexander; Saveliev, Anatoly

    2015-04-01

    In the result of Chernobyl disaster on 26 April 1986 many regions of Ukraine, Belarus and Russia were contaminated by radionuclides. Vast areas of farmlands and woodlands were contaminated in Russia. The deposited radionuclides continue to cause concern about the possible contamination of food (in particular, mushrooms and berries). But the radioactive materials are also an ideal marker for understanding of hillslope processes in natural and seminatural landscapes. Model area chosen for the research (Opolje landscapes located in the central part of the Bryansk region) is characterized by relatively low levels of Cs-137 contamination. It just 4-33 times higher than global fallout which was equal 1,75 kBq/m2 in 1986 . According the results of air gamma survey (grid size: 100 m x100 m), which was done in 1993, it was explicitly to identify that the processes of Cs-137 lateral migration took place due to nearly fourfold increase of Cs-137 in the lower slope in comparison with the surface of the watershed during a seven-year period after Chernobyl accident. Erosion processes which define Cs-137 pattern in the lowest part of hillslope depend upon such parameters as slope, hillslope forms, vegetation, land use and the roads, which intersect a streamline. GIS-modeling of Cs-137 was carried out in SAGA software. The spatial modeling resolution was equal 100x100 m according the air-gamma data. SRTM data was resampled to a grid 100x100 m. Erosion rates were the highest on the slope of southern exposure. There the processes of lateral migration are more intensive and observed within the entire slope. The main contribution in receipt of Cs-137 to floodplain on the northern slopes comes only from the lower part of the slope and gullies and ravines network. We have used geo-information modeling techniques and some kind of interpolation and statistical models to predict or understand forming of Cs-137 spatial patterns and trends in soil erosion. To study the role of some

  5. An empirical model for salt removal percentage in water under the effect of different current intensities of current carrying coil at different flow rates

    Directory of Open Access Journals (Sweden)

    Rameen S. AbdelHady

    2011-10-01

    Full Text Available The magnetic treatment of hard water is an alternative, simple approach by which the hard water that needs to be treated flows through a magnetic field. This field is created by inducing current in a coil wrapped around a pipe. Consequently some of its properties, such as total dissolved salts (TDS, conductivity (Ec and PH change. The primary purpose of hard water treatment is to decrease TDS in the incoming liquid stream. Using performance data from the application of different magnetic field densities on the different flow levels of water, empirical mathematical models were developed relating the salt removal percentage (SRP to operating flow rate and current of the coil. The obtained experimental results showed that the SRP increased with increasing the current at low flow rates (up to 0.75 ml/s.

  6. A new type of coil structure called pan-shaped coil of wireless charging system based on magnetic resonance

    Science.gov (United States)

    Yue, Z. K.; Liu, Z. Z.; Hou, Y. J.; Zeng, H.; Liang, L. H.; Cui, S.

    2017-11-01

    The problem that misalignment between the transmitting coil and the receiving coil significantly impairs the transmission power and efficiency of the system has been attached more and more attention. In order to improve the uniformity of the magnetic field between the two coils to solve this problem, a new type of coil called pan-shaped coil is proposed. Three-dimension simulation models of the planar-core coil and the pan-shaped coil are established using Ansoft Maxwell software. The coupling coefficient between the transmitting coil and the receiving coil is obtained by simulating the magnetic field with the receiving coil misalignment or not. And the maximum percentage difference strength along the radial direction which is defined as the magnetic field uniformity factor is calculated. According to the simulation results of the two kinds of coil structures, it is found that the new type of coil structure can obviously improve the uniformity of the magnetic field, coupling coefficient and power transmission properties between the transmitting coil and the receiving coil.

  7. CCBuilder: an interactive web-based tool for building, designing and assessing coiled-coil protein assemblies.

    Science.gov (United States)

    Wood, Christopher W; Bruning, Marc; Ibarra, Amaurys Á; Bartlett, Gail J; Thomson, Andrew R; Sessions, Richard B; Brady, R Leo; Woolfson, Derek N

    2014-11-01

    The ability to accurately model protein structures at the atomistic level underpins efforts to understand protein folding, to engineer natural proteins predictably and to design proteins de novo. Homology-based methods are well established and produce impressive results. However, these are limited to structures presented by and resolved for natural proteins. Addressing this problem more widely and deriving truly ab initio models requires mathematical descriptions for protein folds; the means to decorate these with natural, engineered or de novo sequences; and methods to score the resulting models. We present CCBuilder, a web-based application that tackles the problem for a defined but large class of protein structure, the α-helical coiled coils. CCBuilder generates coiled-coil backbones, builds side chains onto these frameworks and provides a range of metrics to measure the quality of the models. Its straightforward graphical user interface provides broad functionality that allows users to build and assess models, in which helix geometry, coiled-coil architecture and topology and protein sequence can be varied rapidly. We demonstrate the utility of CCBuilder by assembling models for 653 coiled-coil structures from the PDB, which cover >96% of the known coiled-coil types, and by generating models for rarer and de novo coiled-coil structures. CCBuilder is freely available, without registration, at http://coiledcoils.chm.bris.ac.uk/app/cc_builder/. © The Author 2014. Published by Oxford University Press.

  8. Status of 137Cs contamination in marine biota along the Pacific coast of eastern Japan derived from a dynamic biological model two years simulation following the Fukushima accident

    International Nuclear Information System (INIS)

    Tateda, Yutaka; Tsumune, Daisuke; Tsubono, Takaki; Misumi, Kazuhiro; Yamada, Masatoshi; Kanda, Jota; Ishimaru, Takashi

    2016-01-01

    Radiocesium ( 134 Cs and 137 Cs) released into the Fukushima coastal environment was transferred to marine biota inhabiting the Pacific Ocean coastal waters of eastern Japan. Though the levels in most of the edible marine species decreased overtime, radiocesium concentrations in some fishes were still remained higher than the Japanese regulatory limit for seafood products. In this study, a dynamic food chain transfer model was applied to reconstruct 137 Cs levels in olive flounder by adopting the radiocesium concentrations in small demersal fish which constitute an important fraction of the diet of the olive flounder particularly inhabiting area near Fukushima. In addition, 137 Cs levels in slime flounder were also simulated using reported radiocesium concentrations in some prey organisms. The simulated results from Onahama on the southern border of the Fukushima coastline, and at Choshi the southernmost point where the contaminated water mass was transported by the Oyashio current, were assessed in order to identify what can be explained from present information, and what remains to be clarified three years after the Fukushima Dai-ichi nuclear power plant (1FNPP) accident. As a result, the observed 137 Cs concentrations in planktivorous fish and their predator fish could be explained by the theoretically-derived simulated levels. On the other hand, the slow 137 Cs depuration in slime flounder can be attributed to uptake from unknown sources for which the uptake fluxes were of a similar magnitude as the excretion fluxes. Since the reported 137 Cs concentrations in benthic invertebrates off Onahama were higher than the simulated values, radiocesium transfer from these benthic detritivorous invertebrates to slime flounder via ingestion was suggested as a cause for the observed slow depuration of 137 Cs in demersal fish off southern Fukushima. Furthermore, the slower depuration in the demersal fish likely required an additional source of 137 Cs, i.e. contaminated

  9. Superconducting magnetic coil

    Science.gov (United States)

    Aized, Dawood; Schwall, Robert E.

    1996-06-11

    A superconducting magnetic coil includes a plurality of sections positioned axially along the longitudinal axis of the coil, each section being formed of an anisotropic high temperature superconductor material wound about a longitudinal axis of the coil and having an associated critical current value that is dependent on the orientation of the magnetic field of the coil. The cross section of the superconductor, or the type of superconductor material, at sections along the axial and radial axes of the coil are changed to provide an increased critical current at those regions where the magnetic field is oriented more perpendicularly to the conductor plane, to thereby increase the critical current at these regions and to maintain an overall higher critical current of the coil.

  10. Comparison of gridded versus observation data to initialize ARAC dispersion models for the Algeciras, Spain steel mill CS-137 release

    International Nuclear Information System (INIS)

    Aluzzi, F J; Pace, J C; Pobanz, B M; Vogt, P J

    1999-01-01

    On May 30, 1998 scrap metal containing radioactive Cesium-137 (Cs-137) was accidentally melted in a furnace at the Acerinox steel mill in Algeciras, Spain. Cs-137 was released from the mill's smokestack, and spread across the western Mediterranean Sea to France and Italy and beyond. The first indication of the release was radiation levels up to 1000 times background reported by Swiss, French, and Italian authorities during the following two weeks. Initially no elevated radiation levels were detected over Spain. A release of hazardous material to the atmosphere is the type of situation the Atmospheric Release Advisory Capability (ARAC) emergency response organization was designed to address. The amount and exact time of the release were unknown, though the incident was thought to have taken place during the last week in May. Using air concentration measurements supplied by colleagues of ARAC in Spain, France, Switzerland, Italy, Sweden, Russia and the European Union, ARAC meteorologists estimated the magnitude and timing of the release (Vogt, 1999). Correctly locating the downwind footprint is the most important goal of emergency response modeling. In this study, we compare predicted results for the Algeciras event based on four wind data sources: (1) US Navy Operational Global Atmospheric Prediction System (NOGAPS) data alone, (2) surface and upper air observations alone, (3) NOGAPS data together with surface and upper air observations, and (4) forecasts from ARAC's in-house execution of the U.S. Navy Operational Regional Atmospheric Prediction System (NORAPS) (without surface or upper air observations). We compare the resulting dispersion predictions from ARAC's diagnostic dispersion modeling system to the measurements supplied by our European colleagues to determine which data source produced the best results

  11. Cooling and dehumidifying coils

    International Nuclear Information System (INIS)

    Murthy, M.V.K.

    1988-01-01

    The operating features of cooling and dehumidifying coils and their constructional details are discussed. The heat transfer relations as applicable to the boiling refrigerant and a single phase fluid are presented. Methods of accounting for the effect of moisture condensation on the air side heat transfer coefficient and the fin effectiveness are explained. The logic flow necessary to analyze direct expansion coils and chilled water coils is discussed

  12. The JET divertor coil

    International Nuclear Information System (INIS)

    Last, J.R.; Froger, C.; Sborchia, C.

    1989-01-01

    The divertor coil is mounted inside the Jet vacuum vessel and is able to carry 1 MA turns. It is of conventional construction - water cooled copper, epoxy glass insulation -and is contained in a thin stainless steel case. The coil has to be assembled, insulated and encased inside the Jet vacuum vessel. A description of the coil is given, together with technical information (including mechanical effects on the vacuum vessel), an outline of the manufacture process and a time schedule. (author)

  13. Three-dimensional deformation response of a NiTi shape memory helical-coil actuator during thermomechanical cycling: experimentally validated numerical model

    Science.gov (United States)

    Dhakal, B.; Nicholson, D. E.; Saleeb, A. F.; Padula, S. A., II; Vaidyanathan, R.

    2016-09-01

    Shape memory alloy (SMA) actuators often operate under a complex state of stress for an extended number of thermomechanical cycles in many aerospace and engineering applications. Hence, it becomes important to account for multi-axial stress states and deformation characteristics (which evolve with thermomechanical cycling) when calibrating any SMA model for implementation in large-scale simulation of actuators. To this end, the present work is focused on the experimental validation of an SMA model calibrated for the transient and cyclic evolutionary behavior of shape memory Ni49.9Ti50.1, for the actuation of axially loaded helical-coil springs. The approach requires both experimental and computational aspects to appropriately assess the thermomechanical response of these multi-dimensional structures. As such, an instrumented and controlled experimental setup was assembled to obtain temperature, torque, degree of twist and extension, while controlling end constraints during heating and cooling of an SMA spring under a constant externally applied axial load. The computational component assesses the capabilities of a general, multi-axial, SMA material-modeling framework, calibrated for Ni49.9Ti50.1 with regard to its usefulness in the simulation of SMA helical-coil spring actuators. Axial extension, being the primary response, was examined on an axially-loaded spring with multiple active coils. Two different conditions of end boundary constraint were investigated in both the numerical simulations as well as the validation experiments: Case (1) where the loading end is restrained against twist (and the resulting torque measured as the secondary response) and Case (2) where the loading end is free to twist (and the degree of twist measured as the secondary response). The present study focuses on the transient and evolutionary response associated with the initial isothermal loading and the subsequent thermal cycles under applied constant axial load. The experimental

  14. Statistical validation of the model of diffusion-convection (MDC) of 137Cs for the assessment of recent sedimentation rates in coastal systems

    International Nuclear Information System (INIS)

    Paulo Alves de Lima Ferreira; Eduardo Siegle; Michel Michaelovitch de Mahiques; Rubens Cesar Lopes Figueira; Carlos Augusto Franca Schettini

    2015-01-01

    This study aimed the validation of the model of diffusion-convection (MDC) of 137 Cs for the calculation of recent sedimentation rates in 13 sedimentary cores of two Brazilian coastal systems, the Cananeia-Iguape and Santos-Sao Vicente estuarine systems. The MDC covers key factors responsible for 137 Cs vertical migration in sediments: its diffusion to the interstitial water and the vertical convection of this water through the sediments. This study successfully validated the MDC use to determine sedimentation rates, which was statistically validated not only with 210 Pb xs (unsupported 210 Pb) models, widely used in oceanographic studies, but also by literature values for those regions. (author)

  15. Phytoremediation modelling - phytoextraction of 137Cs, 133Ba, and 90Sr from liquid media and artificially contaminated soil

    International Nuclear Information System (INIS)

    Smrcek, S.; Masnerova, G.

    2002-01-01

    The phytoremediation model based on experiments with plants cultivated in vitro in media supplemented with radionuclide salts was investigated. The plant species Brassica napus, Sinapis alba, Helianthus annuus, Zea mays and Pisum sativum were cultivated on the Murashige-Skoog basal salt mixture enriched with salts of 137 Cs, 133 Ba, and 90 Sr in aseptic conditions. The time-dependent radioactivity decrease in the medium was determined using LSC, and the phytoextraction curves were plotted. Radioactivity in the plant roots and shoots was measured and the efficiency of phytoextraction and the distribution between the roots and shoots as a measure of radionuclide transport in the plant tissues were calculated for each of the plants used. Cultivation experiments were also performed on artificially contaminated soil. Seeds of the plants were placed into contaminated soil and cultivated for 2 months in conditions similar to those of the in vitro experiments. The extracted radioactivity and distribution between roots and shoots were determined. The in vitro experiments simulated extraction of the radionuclide salt from solution analogously to real extraction from the soil solution, while the processes occurring in the rhizosphere were eliminated. The phytoextraction efficiency in terms of the percentage of the starting radioactivity ranged from 12 to 31 % for 90 Sr, 8 to 24% for 137 Cs, and 12 to 17 % for 133 Ba in a cultivation cycle. The root/shoot radioactivity ratios demonstrate that the plant species used may be suitable for real phytoremediation. The experiments in which the plants were cultivated from seeds in artificial contaminated substrate showed that the ability of roots to extract radionuclide salts from their environment remains unchanged. The relative efficiency values were lower than for the extraction from solutions (3 to 11.5 % for 90 Sr, 1.5 to 4 % for 137 Cs, and 1 to 6.2 %, for 133 Ba), but in this process, the equilibrium between the soil particles

  16. Light output measurements and computational models of microcolumnar CsI scintillators for x-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Nillius, Peter, E-mail: nillius@mi.physics.kth.se; Klamra, Wlodek; Danielsson, Mats [Royal Institute of Technology (KTH), Stockholm SE-100 44 (Sweden); Sibczynski, Pawel [National Centre for Nuclear Research, Otwock 05-400 (Poland); Sharma, Diksha; Badano, Aldo [Division of Imaging, Diagnostics, and Software Reliability, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, FDA, Silver Spring, Maryland 20993 (United States)

    2015-02-15

    Purpose: The authors report on measurements of light output and spatial resolution of microcolumnar CsI:Tl scintillator detectors for x-ray imaging. In addition, the authors discuss the results of simulations aimed at analyzing the results of synchrotron and sealed-source exposures with respect to the contributions of light transport to the total light output. Methods: The authors measured light output from a 490-μm CsI:Tl scintillator screen using two setups. First, the authors used a photomultiplier tube (PMT) to measure the response of the scintillator to sealed-source exposures. Second, the authors performed imaging experiments with a 27-keV monoenergetic synchrotron beam and a slit to calculate the total signal generated in terms of optical photons per keV. The results of both methods are compared to simulations obtained with hybridMANTIS, a coupled x-ray, electron, and optical photon Monte Carlo transport package. The authors report line response (LR) and light output for a range of linear absorption coefficients and describe a model that fits at the same time the light output and the blur measurements. Comparing the experimental results with the simulations, the authors obtained an estimate of the absorption coefficient for the model that provides good agreement with the experimentally measured LR. Finally, the authors report light output simulation results and their dependence on scintillator thickness and reflectivity of the backing surface. Results: The slit images from the synchrotron were analyzed to obtain a total light output of 48 keV{sup −1} while measurements using the fast PMT instrument setup and sealed-sources reported a light output of 28 keV{sup −1}. The authors attribute the difference in light output estimates between the two methods to the difference in time constants between the camera and PMT measurements. Simulation structures were designed to match the light output measured with the camera while providing good agreement with the

  17. Strain and stress of the ASDEX multipole magnetic coils

    International Nuclear Information System (INIS)

    Jandl, O.; Pillsticker, M.

    1978-01-01

    A brief description of the technical concept of the multipole magnetic field coils for the ASDEX tokamak is given. The various loads of the coils are explained in quality. To compute displacement and stress of the coils FEM computer programs are used. The computing models applied to this problem are founded and the results and the conclusions are reported. (orig.) [de

  18. Annual deposition of Sr-90, Cs-137 and Pu-239, 240 from the 1961 - 1980 nuclear explosions: a simple model

    International Nuclear Information System (INIS)

    Hirose, K.; Aoyama, M.; Katsuragi, Y.; Sugimura, Y.

    1987-01-01

    The annual deposition of Sr-90, Cs-137, Pu-239, 240, and Pu-238 were observed from 1959 to 1984 at the Meteorological Research Institute (MRI). In order to interpret the serial trends of the annual radioactive deposition at the MRI, a semi-empirical box model of atmospheric transport was developed. The model divides the atmosphere of the Northern Hemisphere into four compartments: the atmosphere above 21 km, stratosphere below 21 km, active mixing and exchange (AME) layer near the tropopause, and the troposphere. The transfer between the compartments follows the first-order kinetics. The half residence times for transfer between upper and lower stratospheric compartments, between the lower and AME layer compartments, and between the AME layer and troposphere are 0.5, 0.7 and 0.3 yrs, respectively. It is revealed that as a long-term monitoring of the annual deposition of radioactive debris in the mid-latitude area, the model quantitatively permits the calculation of stratospheric inventories and trends of annual deposition of debris injected into the stratosphere which are characterized by apparent residence times of 0.5 to 1.7 yrs. This simple model is useful to predict the annual deposition amount of radioactive debris from the thermonuclear explosion for practical purposes. (author)

  19. Characteristics of bowl-shaped coils for transcranial magnetic stimulation

    Science.gov (United States)

    Yamamoto, Keita; Suyama, Momoko; Takiyama, Yoshihiro; Kim, Dongmin; Saitoh, Youichi; Sekino, Masaki

    2015-05-01

    Transcranial magnetic stimulation (TMS) has recently been used as a method for the treatment of neurological and psychiatric diseases. Daily TMS sessions can provide continuous therapeutic effectiveness, and the installation of TMS systems at patients' homes has been proposed. A figure-eight coil, which is normally used for TMS therapy, induces a highly localized electric field; however, it is challenging to achieve accurate coil positioning above the targeted brain area using this coil. In this paper, a bowl-shaped coil for stimulating a localized but wider area of the brain is proposed. The coil's electromagnetic characteristics were analyzed using finite element methods, and the analysis showed that the bowl-shaped coil induced electric fields in a wider area of the brain model than a figure-eight coil. The expanded distribution of the electric field led to greater robustness of the coil to the coil-positioning error. To improve the efficiency of the coil, the relationship between individual coil design parameters and the resulting coil characteristics was numerically analyzed. It was concluded that lengthening the outer spherical radius and narrowing the width of the coil were effective methods for obtaining a more effective and more uniform distribution of the electric field.

  20. Novel transcranial magnetic stimulation coil for mice

    Science.gov (United States)

    March, Stephen; Stark, Spencer; Crowther, Lawrence; Hadimani, Ravi; Jiles, David

    2014-03-01

    Transcranial magnetic stimulation (TMS) shows potential for non-invasive treatment of various neurological disorders. Significant work has been performed on the design of coils used for TMS on human subjects but few reports have been made on the design of coils for use on the brains of animals such as mice. This work is needed as TMS studies utilizing mice can allow rapid preclinical development of TMS for human disorders but the coil designs developed for use on humans are inadequate for optimal stimulation of the much smaller mouse brain. A novel TMS coil has been developed with the goal of inducing strong and focused electric fields for the stimulation of small animals such as mice. Calculations of induced electric fields were performed utilizing an MRI derived inhomogeneous model of an adult male mouse. Mechanical and thermal analysis of this new TMS helmet-coil design have also been performed at anticipated TMS operating conditions to ensure mechanical stability of the new coil and establish expected linear attraction and rotational force values. Calculated temperature increases for typical stimulation periods indicate the helmet-coil system is capable of operating within established medical standards. A prototype of the coil has been fabricated and characterization results are presented.

  1. SU-E-I-11: Cascaded Linear System Model for Columnar CsI Flat Panel Imagers with Depth Dependent Gain and Blur

    International Nuclear Information System (INIS)

    Peng, B; Lubinsky, A; Zheng, H; Zhao, W; Teymurazyan, A

    2014-01-01

    Purpose: To implement a depth dependent gain and blur cascaded linear system model (CLSM) for optimizing columnar structured CsI indirect conversion flat panel imager (FPI) for advanced imaging applications. Methods: For experimental validation, depth dependent escape efficiency, e(z), was extracted from PHS measurement of different CsI scintillators (thickness, substrate and light output). The inherent MTF and DQE of CsI was measured using high resolution CMOS sensor. For CLSM, e(z) and the depth dependent MTF(f,z), were estimated using Monte Carlo simulation (Geant4) of optical photon transport through columnar CsI. Previous work showed that Monte Carlo simulation for CsI was hindered by the non-ideality of its columnar structure. In the present work we allowed variation in columnar width with depth, and assumed diffusive reflective backing and columns. Monte Carlo simulation was performed using an optical point source placed at different depth of the CsI layer, from which MTF(z,f) and e(z) were computed. The resulting e(z) with excellent matching with experimental measurements were then applied to the CLSM, Monte Carlo simulation was repeated until the modeled MTF, DQE(f) also match experimental measurement. Results: For a 150 micron FOS HL type CsI, e(z) varies between 0.56 to 0.45, and the MTF at 14 cycles/mm varies between 62.1% to 3.9%, from the front to the back of the scintillator. The overall MTF and DQE(f) at all frequencies are in excellent agreement with experimental measurements at all frequencies. Conclusion: We have developed a CLSM for columnar CsI scintillators with depth dependent gain and MTF, which were estimated from Monte Carlo simulation with novel optical simulation settings. Preliminary results showed excellent agreement between simulation results and experimental measurements. Future work is aimed at extending this approach to optimize CsI screen optic design and sensor structure for achieving higher DQE(f) in cone-beam CT, which uses

  2. Uncertainty analysis in estimating Japanese ingestion of global fallout Cs-137 using health risk evaluation model

    International Nuclear Information System (INIS)

    Shimada, Yoko; Morisawa, Shinsuke

    1998-01-01

    Most of model estimation of the environmental contamination includes some uncertainty associated with the parameter uncertainty in the model. In this study, the uncertainty was analyzed in a model for evaluating the ingestion of radionuclide caused by the long-term global low-level radioactive contamination by using various uncertainty analysis methods: the percentile estimate, the robustness analysis and the fuzzy estimate. The model is mainly composed of five sub-models, which include their own uncertainty; we also analyzed the uncertainty. The major findings obtained in this study include that the possibility of the discrepancy between predicted value by the model simulation and the observed data is less than 10%; the uncertainty of the predicted value is higher before 1950 and after 1980; the uncertainty of the predicted value can be reduced by decreasing the uncertainty of some environmental parameters in the model; the reliability of the model can definitively depend on the following environmental factors: direct foliar absorption coefficient, transfer factor of radionuclide from stratosphere down to troposphere, residual rate by food processing and cooking, transfer factor of radionuclide in ocean and sedimentation in ocean. (author)

  3. Quadruple Cone Coil with improved focality than Figure-8 coil in Transcranial Magnetic Stimulation

    Science.gov (United States)

    Rastogi, Priyam; Lee, Erik G.; Hadimani, Ravi L.; Jiles, David C.

    Transcranial Magnetic Stimulation (TMS) is a non-invasive therapy which uses a time varying magnetic field to induce an electric field in the brain and to cause neuron depolarization. Magnetic coils play an important role in the TMS therapy since their coil geometry determines the focality and penetration's depth of the induced electric field in the brain. Quadruple Cone Coil (QCC) is a novel coil with an improved focality when compared to commercial Figure-8 coil. The results of this newly designed QCC coil are compared with the Figure-8 coil at two different positions of the head - vertex and dorsolateral prefrontal cortex, over the 50 anatomically realistic MRI derived head models. Parameters such as volume of stimulation, maximum electric, area of stimulation and location of maximum electric field are determined with the help of computer modelling of both coils. There is a decrease in volume of brain stimulated by 11.6 % and a modest improvement of 8 % in the location of maximum electric field due to QCC in comparison to the Figure-8 coil. The Carver Charitable Trust and The Galloway Foundation.

  4. Active internal corrector coils

    International Nuclear Information System (INIS)

    Thompson, P.A.; Cottingham, J.; Dahl, P.

    1986-01-01

    Trim or corrector coils to correct main magnet field errors and provide higher multipole fields for beam optics purposes are a standard feature of superconducting magnet accelerator systems. This paper describes some of the design and construction features of powered internal trim coils and a sampling of the test results obtained

  5. Compact stellarator coils

    International Nuclear Information System (INIS)

    Pomphrey, N.; Berry, L.A.; Boozer, A.H.

    2001-01-01

    Experimental devices to study the physics of high-beta (β>∼4%), low aspect ratio (A<∼4.5) stellarator plasmas require coils that will produce plasmas satisfying a set of physics goals, provide experimental flexibility, and be practical to construct. In the course of designing a flexible coil set for the National Compact Stellarator Experiment, we have made several innovations that may be useful in future stellarator design efforts. These include: the use of Singular Value Decomposition methods for obtaining families of smooth current potentials on distant coil winding surfaces from which low current density solutions may be identified; the use of a Control Matrix Method for identifying which few of the many detailed elements of the stellarator boundary must be targeted if a coil set is to provide fields to control the essential physics of the plasma; the use of Genetic Algorithms for choosing an optimal set of discrete coils from a continuum of potential contours; the evaluation of alternate coil topologies for balancing the tradeoff between physics objective and engineering constraints; the development of a new coil optimization code for designing modular coils, and the identification of a 'natural' basis for describing current sheet distributions. (author)

  6. iDynoMiCS: next‐generation individual‐based modelling of biofilms

    DEFF Research Database (Denmark)

    Lardon, Laurent; Merkey, Brian; Martins, Sónia

    2011-01-01

    how environmentally fluctuating oxygen availability affects the diversity and composition of a community of denitrifying bacteria that induce the denitrification pathway under anoxic or low oxygen conditions. We tested the hypothesis that the existence of these diverse strategies of denitrification...... and higher at intermediate frequency of change. The highly modular nature of the new computational model made this case study straightforward to implement, and reflects the sort of novel studies that can easily be executed with the new model....

  7. CS Informativeness Governs CS-US Associability

    Science.gov (United States)

    Ward, Ryan D.; Gallistel, C. R.; Jensen, Greg; Richards, Vanessa L.; Fairhurst, Stephen; Balsam, Peter D

    2012-01-01

    In a conditioning protocol, the onset of the conditioned stimulus (CS) provides information about when to expect reinforcement (the US). There are two sources of information from the CS in a delay conditioning paradigm in which the CS-US interval is fixed. The first depends on the informativeness, the degree to which CS onset reduces the average expected time to onset of the next US. The second depends only on how precisely a subject can represent a fixed-duration interval (the temporal Weber fraction). In three experiments with mice, we tested the differential impact of these two sources of information on rate of acquisition of conditioned responding (CS-US associability). In Experiment 1, we show that associability (the inverse of trials to acquisition) increases in proportion to informativeness. In Experiment 2, we show that fixing the duration of the US-US interval or the CS-US interval or both has no effect on associability. In Experiment 3, we equated the increase in information produced by varying the C̅/T̅ ratio with the increase produced by fixing the duration of the CS-US interval. Associability increased with increased informativeness, but, as in Experiment 2, fixing the CS-US duration had no effect on associability. These results are consistent with the view that CS-US associability depends on the increased rate of reward signaled by CS onset. The results also provide further evidence that conditioned responding is temporally controlled when it emerges. PMID:22468633

  8. Organic titanates: a model for activating rapid room-temperature synthesis of shape-controlled CsPbBr3 nanocrystals and their derivatives.

    Science.gov (United States)

    Fang, Shaofan; Li, Guangshe; Li, Huixia; Lu, Yantong; Li, Liping

    2018-04-12

    The application of lead halide perovskite nanocrystals is challenged by the lack of strategies in rapid room-temperature synthesis with controlled morphologies. Here, we report on an initial study of adopting organic titanates as a model activator that promotes rapid room-temperature synthesis of shape-controlled, highly luminescent CsPbBr3 nanocrystals and their derivatives.

  9. SU-F-T-43: Prediction of Dose Increments by Brain Metastases Resection Cavity Shrinkage Model with I-125 and Cs-131 LDR Seed Implantations

    Energy Technology Data Exchange (ETDEWEB)

    Han, D; Braunstein, S; Sneed, P; McDermott, M; Ma, L [University of California San Francisco, San Francisco, CA (United States)

    2016-06-15

    Purpose: This work aims to determine dose variability via a brain metastases resection cavity shrinkage model (RC-SM) with I-125 or Cs-131 LDR seed implantations. Methods: The RC-SM was developed to represent sequential volume changes of 95 consecutive brain metastases patients. All patients underwent serial surveillance MR and change in cavity volume was recorded for each patient. For the initial resection cavity, a prolate-ellipsoid cavity model was suggested and applied volume shrinkage rates to correspond to 1.7, 3.6, 5.9, 11.7, and 20.5 months after craniotomy. Extra-ring structure (6mm) was added on a surface of the resection volume and the same shrinkage rates were applied. Total 31 LDR seeds were evenly distributed on the surface of the resection cavity. The Amersham 6711 I-125 seed model (Oncura, Arlington Heights, IL) and the Model Cs-1 Rev2 Cs-131 seed model (IsoRay, Richland, WA) were used for TG-43U1 dose calculation and in-house-programed 3D-volumetric dose calculation system was used for resection cavity rigid model (RC-RM) and the RC-SM dose calculation. Results: The initial resection cavity volume shrunk to 25±6%, 35±6.8%, 42±7.7%, 47±9.5%, and 60±11.6%, with respect to sequential MR images post craniotomy, and the shrinkage rate (SR) was calculated as SR=56.41Xexp(−0.2024Xt)+33.99 and R-square value was 0.98. The normal brain dose as assessed via the dose to the ring structure with the RC-SM showed 29.34% and 27.95% higher than the RC-RM, I-125 and Cs-131, respectively. The dose differences between I-125 and Cs-131 seeds within the same models, I-125 cases were 9.17% and 10.35% higher than Cs-131 cases, the RC-RM and the RC-SM, respectively. Conclusion: A realistic RC-SM should be considered during LDR brain seed implementation and post-implement planning to prevent potential overdose. The RC-SM calculation shows that Cs-131 is more advantageous in sparing normal brain as the resection cavity volume changes with the LDR seeds implementation.

  10. Tolerance Evaluation of Poloidal Shear Keys for ITER TF Coil

    International Nuclear Information System (INIS)

    Fu Youkun; Neil, M.; Cees Jong

    2006-01-01

    There are 18 ITER Toroidal Field (TF) Coils. Unlike the other ITER coils, these coils are structurally linked. These links consist of friction between the coil legs in the central vault formed by the inner straight legs of the coils, four outer inter-coil structures (OIS) and one inner inter-coil structure (IIS). The OIS consists essentially of bands around all 18 coils to provide shear support by forming shear panels with the coil case, and the IIS consists of poloidal circular keys placed directly between the coil cases. Global analysis of the 'perfect' coil shape has shown high stresses in the IIS, in the poloidal keyways. Optimization has successfully reduced these stresses to acceptable values as regards the expected fatigue resistance. However it is necessary to confirm that the stresses are still acceptable when realistic values of geometry variations are included (i.e. the effect of coil and case tolerances). Because of the extensive mechanical links between coils the poloidal key stresses can also be affected by tolerances elsewhere in the case. As the first step in assessment of the possible variations in stresses, a substructure technique is being used to develop a local model of the key region. The result of geometry variations between individual coils is a loss in the 18 fold symmetry used to simplify previous analyses. With the new and optimized model it should be possible to relax the 18-fold symmetry, but a full analysis of all 18 coils is still not possible. Systematic ways of representing the tolerance variation in the finite element model have been developed so that parametric studies can be undertaken without a full reconstruction of the model. (author)

  11. Bioavailability of Cs radionuclides in forest regions - data acquisition and modelling. Applications and appendix 1-4

    International Nuclear Information System (INIS)

    Klemt, E.

    1999-10-01

    A model of radiocaesium soil-plant transfer is proposed, combining two separate approaches to describe radionuclide distribution in soil-soil solution system and soil solution-plant system. According to the model radiocaesium concentration in soil solution is determined by abilities of soil to fix and selectively sorb radiocaesium as well as cationic composition of soil solution. Soil solution - plant transfer is determined by Cs concentration in soil solution and also by cationic status of soil solution. It is derived that soil-plant transfer factor should be a linear function of availability parameter A of the soil which is a combination of soil parameters and cationic status of soil solution. The parametrisation is tested against the field data on soil-plant transfer for various forest sites in Germany, Russia, Sweden and Switzerland. Satisfactory agreement has been achieved. A simplified method of the parameterisation based on the application standard argochemical characteristics of soil is presented and experimentally tested. The approach can be used in radioecological GIS to map radiocaesium soil-plant transfer factor. (orig.)

  12. Study on the performance improvement of the high temperature superconducting coil with several separated coils at the edges

    International Nuclear Information System (INIS)

    Ishiguri, S.; Oka, T.; Fukui, S.; Ogawa, J.; Sato, T.

    2008-01-01

    In designing high temperature superconducting (HTS) coils, it is important to secure large magnetic fields and stored energy using shorter tape length. Thus, it is necessary to improve the transport current performance of the coils. The critical current and n-value of an HTS tape depend on magnetic fields and flux angles under constant temperature. Considering these dependencies, we established a model to analyze coil critical current. This model clarifies that relatively large electric fields are generated at the coil edges. This adversely affects the transport current performance. In this study, the coil edge is separated into several coils, keeping the total tape length constant. This increases the coil critical current, stored energy, central magnetic field, and also the coil volume, which contains vacancies created by the separation. To estimate coil performance, we calculated the stored energy density, whose denominator is the increased coil volume. This stored energy density reaches its maximum value when the number of the separated coils is eight. At this optimum separation, the central magnetic field increases by 13%, and the stored energy improves by 43%, compared to a rectangular coil wound with the same tape length

  13. Large coil task and results of testing US coils

    International Nuclear Information System (INIS)

    Haubenreich, P.N.

    1986-01-01

    The United States, EURATOM, Japan, and Switzerland have collaborated since 1978 in development of superconducting toroidal field coils for fusion reactor applications. The United States provided a test facility nd three coils; the other participants, one coil each. All coils have the same interface dimensions and performance requirements (stable at 8 T), but internal design was decided by each team. Two US coil teams chose bath-cooled NbTi, 10-kA conductors. One developed a Nb 3 Sn conductor, cooled by internal flow, rated at 18 kA. All US coils have diagnostic instrumentation and imbedded heaters that enable stability tests and simulated nuclear heating experiments. In single-coil tests, each coil operated at full current in self-field (6.4 T). In six-coil tests that began in July 1986, one US coil and the Japanese coil hve been successfully operated at full current at 8 T. The other coils have operated as background coils while awaiting their turn as test coil. Coil tests have been informative and results gratifying. The facility has capably supported coil testing and its operation has provided information that will be useful in designing future fusion systems. Coil capabilities beyond nominal design points will be determined

  14. Switching transients in a superconducting coil

    International Nuclear Information System (INIS)

    Owen, E.W.; Shimer, D.W.

    1983-01-01

    A study is made of the transients caused by the fast dump of large superconducting coils. Theoretical analysis, computer simulation, and actual measurements are used. Theoretical analysis can only be applied to the simplest of models. In the computer simulations two models are used, one in which the coil is divided into ten segments and another in which a single coil is employed. The circuit breaker that interrupts the current to the power supply, causing a fast dump, is represented by a time and current dependent conductance. Actual measurements are limited to measurements made incidental to performance tests on the MFTF Yin-yang coils. It is found that the breaker opening time is the critical factor in determining the size and shape of the transient. Instantaneous opening of the breaker causes a lightly damped transient with large amplitude voltages to ground. Increasing the opening time causes the transient to become a monopulse of decreasing amplitude. The voltages at the external terminals are determined by the parameters of the external circuit. For fast opening times the frequency depends on the dump resistor inductance, the circuit capacitance, and the amplitude on the coil current. For slower openings the dump resistor inductance and the current determine the amplitude of the voltage to ground at the terminals. Voltages to ground are less in the interior of the coil, where transients related to the parameters of the coil itself are observed

  15. Commercial applications for COIL

    Science.gov (United States)

    Solomon, Wayne C.; Carroll, David L.; King, D. M.; Fockler, L. A.; Stromberg, D. S.; Sexauer, M.; Milmoe, A.; Sentman, Lee H.

    2000-01-01

    The chemical oxygen-iodine laser (COIL) is a high power, fiber deliverable tool, which can be used for a number of different industrial applications. COIL is of particular interest because of its short fiber deliverable wavelength, high scaleable continuous wave power, and excellent material interaction properties. In past research the University of Illinois at Urbana-Champaign identified and decommissioning and decontamination (DD) of nuclear facilities as a primary focus for COIL technology. DD will be a major challenge in the coming decades. The use of a robotically driven fiber delivered cutting/ablation tool in contaminated areas promises to lower risks to workers for the DD mission. Further, the high cutting speed of COIL will significantly reduce the time required to cut contaminated equipment, reducing costs. The high power of COIL will permit the dismantling of thick stacks of piping and equipment as well as reactor vessels. COIL is very promising for the removal of material from contaminated surfaces, perhaps to depths thicker than an inch. Laser cutting and ablation minimizes dust and fumes, which reduces the required number of high efficiency particulate accumulator filters, thus reducing costly waste disposal. Other potential industrial applications for COIL are shipbuilding, automotive manufacturing, heavy machinery manufacturing, tasks requiring underwater cutting or welding, and there appear to be very promising applications for high powers lasers in the oil industry.

  16. Open coil traction system.

    Science.gov (United States)

    Vibhute, Pavankumar Janardan

    2012-01-01

    Sliding mechanics have become a popular method for space closure, with the development of preadjusted edgewise appliances. Furthermore, various space closing auxiliaries have been developed and extensively evaluated for their clinical efficiency. Their effectiveness is enhanced with optimum force magnitude and low load deflection rate/force decay. With the advent of nickel-titanium (Ni-Ti) springs in orthodontics, load deflection rates have been markedly reduced. To use Ni-Ti springs, clinicians have to depend upon prefabricated closed coil springs. The open coil traction system, or open coil retraction spring, is developed utilizing Ni-Ti open coil springs for orthodontic space closure. This article describes the fabrication and clinical application of the open coil traction system, which has a number of advantages. It sustains a low load deflection rate with optimum force magnitude, and its design is adjustable for a desired length and force level. It is fail-safe for both activation and deactivation (ie, it cannot be overactivated, and the decompression limit of the open coil is controlled by the operator). The open coil traction system can be offset from the mucosa to help reduce soft tissue impingement.

  17. Three-dimensional simulation of beam propagation and heat transfer in static gas Cs DPALs using wave optics and fluid dynamics models

    Science.gov (United States)

    Waichman, Karol; Barmashenko, Boris D.; Rosenwaks, Salman

    2017-10-01

    Analysis of beam propagation, kinetic and fluid dynamic processes in Cs diode pumped alkali lasers (DPALs), using wave optics model and gasdynamic code, is reported. The analysis is based on a three-dimensional, time-dependent computational fluid dynamics (3D CFD) model. The Navier-Stokes equations for momentum, heat and mass transfer are solved by a commercial Ansys FLUENT solver based on the finite volume discretization technique. The CFD code which solves the gas conservation equations includes effects of natural convection and temperature diffusion of the species in the DPAL mixture. The DPAL kinetic processes in the Cs/He/C2H6 gas mixture dealt with in this paper involve the three lowest energy levels of Cs, (1) 62S1/2, (2) 62P1/2 and (3) 62P3/2. The kinetic processes include absorption due to the 1->3 D2 transition followed by relaxation the 3 to 2 fine structure levels and stimulated emission due to the 2->1 D1 transition. Collisional quenching of levels 2 and 3 and spontaneous emission from these levels are also considered. The gas flow conservation equations are coupled to fast-Fourier-transform algorithm for transverse mode propagation to obtain a solution of the scalar paraxial propagation equation for the laser beam. The wave propagation equation is solved by the split-step beam propagation method where the gain and refractive index in the DPAL medium affect the wave amplitude and phase. Using the CFD and beam propagation models, the gas flow pattern and spatial distributions of the pump and laser intensities in the resonator were calculated for end-pumped Cs DPAL. The laser power, DPAL medium temperature and the laser beam quality were calculated as a function of pump power. The results of the theoretical model for laser power were compared to experimental results of Cs DPAL.

  18. Coil spring venting arrangement

    International Nuclear Information System (INIS)

    McCugh, R.M.

    1975-01-01

    A simple venting device for trapped gas pockets in hydraulic systems is inserted through a small access passages, operated remotely, and removed completely. The device comprises a small diameter, closely wound coil spring which is pushed through a guide temporarily inserted in the access passage. The guide has a central passageway which directs the coil spring radially upward into the pocket, so that, with the guide properly positioned for depth and properly oriented, the coil spring can be pushed up into the top of the pocket to vent it. By positioning a seal around the free end of the guide, the spring and guide are removed and the passage is sealed

  19. Modeling dynamics of "1"3"7Cs in forest surface environments: Application to a contaminated forest site near Fukushima and assessment of potential impacts of soil organic matter interactions

    International Nuclear Information System (INIS)

    Ota, Masakazu; Nagai, Haruyasu; Koarashi, Jun

    2016-01-01

    A process-based model for "1"3"7Cs transfer in forest surface environments was developed to assess the dynamic behavior of Fukushima-derived "1"3"7Cs in a Japanese forest. The model simulation successfully reproduced the observed data from 3 year migration of "1"3"7Cs in the organic and mineral soil layers at a contaminated forest near Fukushima. The migration of "1"3"7Cs from the organic layer to the mineral soil was explained by the direct deposition pattern on the forest floor and the turnover of litter materials in the organic layer under certain ecological conditions. Long-term predictions indicated that more than 90% of the deposited "1"3"7Cs would remain within the top 5 cm of the soil for up to 30 years after the accident, suggesting that the forest acts as an effective long-term reservoir of "1"3"7Cs with limited transfer via the groundwater pathway. The model was also used to explore the potential impacts of soil organic matter (SOM) interactions on the mobility and bioavailability of "1"3"7Cs in the soil–plant system. The simulation results for hypothetical organic soils with modified parameters of "1"3"7Cs turnover revealed that the SOM-induced reduction of "1"3"7Cs adsorption elevates the fraction of dissolved "1"3"7Cs in the soil solution, thereby increasing the soil-to-plant transfer of "1"3"7Cs without substantially altering the fractional distribution of "1"3"7Cs in the soil. Slower fixation of "1"3"7Cs on the flayed edge site of clay minerals and enhanced mobilization of the clay-fixed "1"3"7Cs in organic-rich soils also appeared to elevate the soil-to-plant transfer of "1"3"7Cs by increasing the fraction of the soil-adsorbed (exchangeable) "1"3"7Cs. A substantial proportion (approximate 30%–60%) of "1"3"7Cs in these organic-rich soils was transferred to layers deeper than 5 cm decades later. These results suggested that SOM influences the behavior of "1"3"7Cs in forests over a prolonged period through alterations of adsorption and fixation in

  20. Extending the self-assembly of coiled-coil hybrids

    NARCIS (Netherlands)

    Robson Marsden, Hana

    2009-01-01

    Of the various biomolecular building blocks in use in nature, coiled-coil forming peptides are amongst those with the most potential as building blocks for the synthetic self-assembly of nanostructures. Native coiled coils have the ability to function in, and influence, complex systems composed of

  1. Modeling of 137Cs and 90Sr behavior in the soil-plant system within the territory adjacent to 'Experimental field' technical site in the Semipalatinsk test site

    International Nuclear Information System (INIS)

    Spiridonov, S.I.; Gontarenko, I.A.; Mukusheva, M.K.

    2005-01-01

    Modelling of 137 Cs and 90 Sr behavior in the soil-plant system is presented. Models have been parameterized for the area adjacent to the 'Experimental Field' Technical Site of the Semipalatinsk Test Site. The models describe the main processes responsible for changes of 137 Cs and 90 Sr content in the soil solution and, thereby, dynamics of radionuclides intake by vegetation. Results are presented from perspective and retrospective calculations, that reflect the dynamics of 137 and 90 Sr distribution by species in soil after nuclear explosions. The importance of factors governing radionuclide accumulation in plants within Semipalatinsk test site area is assessed. The analysis of sensitivity of model output variable to change in its parameters has revealed that the key soil properties significantly influence the results of prediction of radionuclide content in plants. (author)

  2. A periodic table of coiled-coil protein structures.

    Science.gov (United States)

    Moutevelis, Efrosini; Woolfson, Derek N

    2009-01-23

    Coiled coils are protein structure domains with two or more alpha-helices packed together via interlacing of side chains known as knob-into-hole packing. We analysed and classified a large set of coiled-coil structures using a combination of automated and manual methods. This led to a systematic classification that we termed a "periodic table of coiled coils," which we have made available at http://coiledcoils.chm.bris.ac.uk/ccplus/search/periodic_table. In this table, coiled-coil assemblies are arranged in columns with increasing numbers of alpha-helices and in rows of increased complexity. The table provides a framework for understanding possibilities in and limits on coiled-coil structures and a basis for future prediction, engineering and design studies.

  3. DESIGNING A COMPETITIVE ADVANTAGE MODEL WITH TECHNOLOGY ORIENTED APPROACH USING FAHP TECHNIQUE: A CASE STUDY IN COIL INDUSTRY

    Directory of Open Access Journals (Sweden)

    ABDOLHAMID S. GHADIKOLAEI

    2013-04-01

    Full Text Available One of the distinctive attributes of today’s successful companies is having at least one competitive advantage in one known area. Technological competency is an important advantage which helps improve the firm’s competitiveness. In fact, suitable use of new technologies can dramatically influence the innovation speed, decrease the time of product development cycle and also increase the rate of new product introduction. Firm-specific technological competencies help explain why a firm is different, how it changes over time, and whether it is capable of remaining competitive. In this study, technological competency factors (technology management, process technology, product technology are prioritized according to the competitive advantage levels(customer satisfaction, brand reputation, new product introduction, market share and competitive priorities (cost, price, quality, flexibility, time using fuzzy Analytic hierarchy process (FAHP with the aim of maximizing the nonfinancial performance at coil manufacture industry. The results indicate that within Iran coil industry, process technology is of greater importance than technology management and product technology.

  4. LHC bending magnet coil

    CERN Multimedia

    A short test version of coil of wire used for the LHC dipole magnets. The high magnetic fields needed for guiding particles around the Large Hadron Collider (LHC) ring are created by passing 12’500 amps of current through coils of superconducting wiring. At very low temperatures, superconductors have no electrical resistance and therefore no power loss. The LHC is the largest superconducting installation ever built. The magnetic field must also be extremely uniform. This means the current flowing in the coils has to be very precisely controlled. Indeed, nowhere before has such precision been achieved at such high currents. Magnet coils are made of copper-clad niobium–titanium cables — each wire in the cable consists of 9’000 niobium–titanium filaments ten times finer than a hair.

  5. Borehole induction coil transmitter

    Science.gov (United States)

    Holladay, Gale; Wilt, Michael J.

    2002-01-01

    A borehole induction coil transmitter which is a part of a cross-borehole electromagnetic field system that is used for underground imaging applications. The transmitter consists of four major parts: 1) a wound ferrite or mu-metal core, 2) an array of tuning capacitors, 3) a current driver circuit board, and 4) a flux monitor. The core is wound with several hundred turns of wire and connected in series with the capacitor array, to produce a tuned coil. This tuned coil uses internal circuitry to generate sinusoidal signals that are transmitted through the earth to a receiver coil in another borehole. The transmitter can operate at frequencies from 1-200 kHz and supplies sufficient power to permit the field system to operate in boreholes separated by up to 400 meters.

  6. Eccentric figure-eight coils for transcranial magnetic stimulation.

    Science.gov (United States)

    Sekino, Masaki; Ohsaki, Hiroyuki; Takiyama, Yoshihiro; Yamamoto, Keita; Matsuzaki, Taiga; Yasumuro, Yoshihiro; Nishikawa, Atsushi; Maruo, Tomoyuki; Hosomi, Koichi; Saitoh, Youichi

    2015-01-01

    Previously we proposed an eccentric figure-eight coil that can cause threshold stimulation in the brain at lower driving currents. In this study, we performed numerical simulations and magnetic stimulations to healthy subjects for evaluating the advantages of the eccentric coil. The simulations were performed using a simplified spherical brain model and a realistic human brain model. We found that the eccentric coil required a driving current intensity of approximately 18% less than that required by the concentric coil to cause comparable eddy current densities within the brain. The eddy current localization of the eccentric coil was slightly higher than that of the concentric coil. A prototype eccentric coil was designed and fabricated. Instead of winding a wire around a bobbin, we cut eccentric-spiral slits on the insulator cases, and a wire was woven through the slits. The coils were used to deliver magnetic stimulation to healthy subjects; among our results, we found that the current slew rate corresponding to motor threshold values for the concentric and eccentric coils were 86 and 78 A/µs, respectively. The results indicate that the eccentric coil consistently requires a lower driving current to reach the motor threshold than the concentric coil. Future development of compact magnetic stimulators will enable the treatment of some intractable neurological diseases at home. © 2014 Wiley Periodicals, Inc.

  7. Improved SNR of phased-array PERES coils via simulation study

    International Nuclear Information System (INIS)

    RodrIguez, Alfredo O; Medina, LucIa

    2005-01-01

    A computational comparison of signal-to-noise ratio (SNR) was performed between a conventional phased array of two circular-shaped coils and a petal resonator surface array. The quasi-static model and phased-array optimum SNR were combined to derive an SNR formula for each array. Analysis of mutual inductance between coil petals was carried out to compute the optimal coil separation and optimum number of petal coils. Mutual interaction between coil arrays was not included in the model because this does not drastically affect coil performance. Phased arrays of PERES coils show a 114% improvement in SNR over that of the simplest circular configuration. (note)

  8. Radiation induced currents in mineral-insulated cables and in pick-up coils: model calculations and experimental verification in the BR1 reactor

    Science.gov (United States)

    Vermeeren, Ludo; Leysen, Willem; Brichard, Benoit

    2018-01-01

    Mineral-insulated (MI) cables and Low-Temperature Co-fired Ceramic (LTCC) magnetic pick-up coils are intended to be installed in various position in ITER. The severe ITER nuclear radiation field is expected to lead to induced currents that could perturb diagnostic measurements. In order to assess this problem and to find mitigation strategies models were developed for the calculation of neutron-and gamma-induced currents in MI cables and in LTCC coils. The models are based on calculations with the MCNPX code, combined with a dedicated model for the drift of electrons stopped in the insulator. The gamma induced currents can be easily calculated with a single coupled photon-electron MCNPX calculation. The prompt neutron induced currents requires only a single coupled neutron-photon-electron MCNPX run. The various delayed neutron contributions require a careful analysis of all possibly relevant neutron-induced reaction paths and a combination of different types of MCNPX calculations. The models were applied for a specific twin-core copper MI cable, for one quad-core copper cable and for silver conductor LTCC coils (one with silver ground plates in order to reduce the currents and one without such silver ground plates). Calculations were performed for irradiation conditions (neutron and gamma spectra and fluxes) in relevant positions in ITER and in the Y3 irradiation channel of the BR1 reactor at SCK•CEN, in which an irradiation test of these four test devices was carried out afterwards. We will present the basic elements of the models and show the results of all relevant partial currents (gamma and neutron induced, prompt and various delayed currents) in BR1-Y3 conditions. Experimental data will be shown and analysed in terms of the respective contributions. The tests were performed at reactor powers of 350 kW and 1 MW, leading to thermal neutron fluxes of 1E11 n/cm2s and 3E11 n/cm2s, respectively. The corresponding total radiation induced currents are ranging from

  9. On modular stellarator reactor coils

    International Nuclear Information System (INIS)

    Rau, F.; Harmeyer, E.; Kisslinger, J.; Wobig, H.

    1985-01-01

    Modular twisted coils are discussed which produce magnetic fields of the Advanced Stellarator WENDELSTEIN VII-AS type. Reducing the number coils/FP offers advantage for maintenance of coils, but increases the magnetic ripple and B m /B o . Computation of force densities within the coils of ASR and ASB yield local maximum values of about 80 and 180 MN/m 3 , respectively. A system of mutual coil support is being developed. Twisted coils in helical arrangement provide a reactor-sized HELIAC system. In order to reduce the magnetic ripple, a large number of 14 coils/FP in special arrangement is used

  10. TFTR toroidal field coil design

    International Nuclear Information System (INIS)

    Smith, G.E.; Punchard, W.F.B.

    1977-01-01

    The design of the Tokamak Fusion Test Reactor (TFTR) Toroidal Field (TF) magnetic coils is described. The TF coil is a 44-turn, spiral-wound, two-pancake, water-cooled configuration which, at a coil current of 73.3 kiloamperes, produces a 5.2-Tesla field at a major radius of 2.48 meters. The magnetic coils are installed in titanium cases, which transmit the loads generated in the coils to the adjacent supporting structure. The TFTR utilizes 20 of these coils, positioned radially at 18 0 intervals, to provide the required toroidal field. Because it is very highly loaded and subject to tight volume constraints within the machine, the coil presents unique design problems. The TF coil requirements are summarized, the coil configuration is described, and the problems highlighted which have been encountered thus far in the coil design effort, together with the development tests which have been undertaken to verify the design

  11. NCSX Toroidal Field Coil Design

    International Nuclear Information System (INIS)

    Kalish M; Rushinski J; Myatt L; Brooks A; Dahlgren F; Chrzanowski J; Reiersen W; Freudenberg K.

    2005-01-01

    The National Compact Stellarator Experiment (NCSX) is an experimental device whose design and construction is underway at the Department of Energy's Princeton Plasma Physics Laboratory (PPPL). The primary coil systems for the NCSX device consist of the twisted plasma-shaping Modular Coils, the Poloidal Field Coils, and the Toroidal Field (TF) Coils. The TF Coils are D-shaped coils wound from hollow copper conductor, and vacuum impregnated with a glass-epoxy resin system. There are 18 identical, equally spaced TF coils providing 1/R field at the plasma. They operate within a cryostat, and are cooled by LN2, nominally, to 80K. Wedge shaped castings are assembled to the inboard face of these coils, so that inward radial loads are reacted via the nesting of each of the coils against their adjacent partners. This paper outlines the TF Coil design methodology, reviews the analysis results, and summarizes how the design and analysis support the design requirements

  12. Coil protection calculator for TFTR

    International Nuclear Information System (INIS)

    Marsala, R.J.; Woolley, R.D.

    1987-01-01

    A new coil protection calculator (CPC) is presented in this paper. It is now being developed for TFTR's magnetic field coils will replace the existing coil fault detector. The existing fault detector sacrifices TFTR operating capability for simplicity. The new CPC will permit operation up to the actual coil limits by accurately and continuously computing coil parameters in real-time. The improvement will allow TFTR to operate with higher plasma currents and will permit the optimization of pulse repetition rates

  13. Wash-off of Sr-90 and Cs-137 from two experimental plots. Model testing using Chernobyl data

    International Nuclear Information System (INIS)

    Konoplev, A.; Bulgakov, A.; Hoffman, O.; Thiessen, K.

    1996-09-01

    Surface water runoff from contaminated land is one of the major processes responsible for the contamination of water bodies. For example, the large area of land contaminated after the Chernobyl accident has become a continuing source of radionuclide contamination for natural waters and the aquatic ecosystem. Based on data from the Chernobyl accident, the 'Wash-off' scenario was developed to provide an opportunity to test models concerned with the movement of trace contaminants from terrestrial sources to water bodies. In particular, this scenario provides an opportunity for (1) evaluation of the movement of contaminants from soil to water, (2) calculation of the alteration and migration of contaminants in soil over different time scales, (3) increased understanding of contaminant transport at the process level, and (4) development and use of methods for estimation of key parameters. Modelers were provided with descriptions of two experimental plots near the Chernobyl NPP, one using simulated heavy rain (plot HR) and one using snow melt (plot SM). Initial information for plot HR included soil properties; hydrographs of rainfall and runoff dynamics; the time of application of rainfall; rainfall amounts, duration, and intensities; soil moisture content before the application of rainfall; regional data on average monthly precipitation and temperature; recorded information on naturally occurring precipitation between May and October 1986; and chemical forms of radionuclides in the soil of the plots prior to the experiments. Information for plot SM included the soil description and properties, snow storage in the snow melt period of 1988, chemical composition of the snow water, a hydrograph of the runoff dynamics, chemical radionuclide forms in the soil at the end of the experiment, and air and soil temperatures for the plot during the snow melt period. For each experimental plot, modelers were requested to estimate the vertical distribution of radionuclides (137 Cs and

  14. Design and modelling of a silicon optical MEMS switch controlled by magnetic field generated by a plain coil

    International Nuclear Information System (INIS)

    Golebiowski, J; Milcarz, Sz

    2014-01-01

    Optical switches can be made as a silicon cantilever with a magnetic layer. Such a structure is placed in a magnetic field of a planar coil. There is a torque deflecting the silicon beam with NiFe layer depending on a flux density of the magnetic field. The study shows an analysis of ferromagnetic layer parameters, beam's dimensions on optical switch characteristics. Different constructions of the beams were simulated for a range of values of magnetic field strength from 100 to 1000 A/m. An influence of the actuators parameters on characteristics was analysed. The loss of stiffness of the beam caused by specific constructions effected in displacements reaching 85 nm. Comsol Multiphysics 4.3b was used for the simulations.

  15. Deep brain transcranial magnetic stimulation using variable "Halo coil" system

    Science.gov (United States)

    Meng, Y.; Hadimani, R. L.; Crowther, L. J.; Xu, Z.; Qu, J.; Jiles, D. C.

    2015-05-01

    Transcranial Magnetic Stimulation has the potential to treat various neurological disorders non-invasively and safely. The "Halo coil" configuration can stimulate deeper regions of the brain with lower surface to deep-brain field ratio compared to other coil configurations. The existing "Halo coil" configuration is fixed and is limited in varying the site of stimulation in the brain. We have developed a new system based on the current "Halo coil" design along with a graphical user interface system that enables the larger coil to rotate along the transverse plane. The new system can also enable vertical movement of larger coil. Thus, this adjustable "Halo coil" configuration can stimulate different regions of the brain by adjusting the position and orientation of the larger coil on the head. We have calculated magnetic and electric fields inside a MRI-derived heterogeneous head model for various positions and orientations of the coil. We have also investigated the mechanical and thermal stability of the adjustable "Halo coil" configuration for various positions and orientations of the coil to ensure safe operation of the system.

  16. 12 tesla test coil. Annual progress report

    International Nuclear Information System (INIS)

    1979-01-01

    The Plasma Fusion Center at MIT has been charged with responsibility for the design, development, fabrication and test operation of a Niobium-3-Tin Superconducting Test Coil. Research is described on DOE's 12 tesla coil demonstration program in which several one-meter diameter superconducting test coils will be inserted and tested in DOE's High Field Test Facility at the Lawrence Livermore Laboratories. The work was initiated at the start of FY 79. FY 79 saw the completion of our Preliminary Design and the initiation of three (3) subcontracts: (1) Westinghouse review of the Preliminary Design, (II) Supercon, Inc. development of a tubular copper matrix, Nb 3 Sn Superconductor and (III) Airco optimization of the LCP-W Nb 3 Sn superconductor for 12T service. In addition, Airco was charged with the production of a 1000 foot length of model 15,000A conductor. Coil winding exercises were initiated at the Everson Electric Company

  17. A prospective, randomized, controlled study demonstrating a novel, effective model of transfer of care between physicians: the 5 Cs of consultation.

    Science.gov (United States)

    Kessler, Chad S; Afshar, Yalda; Sardar, Gurkiran; Yudkowsky, Rachel; Ankel, Felix; Schwartz, Alan

    2012-08-01

    The objective was to evaluate whether a standardized consultation model in the emergency department (ED), the 5 Cs of Consultation (Contact, Communicate, Core Question, Collaboration, and Closing the Loop), would improve physicians' ability to relay appropriate information and communicate successfully during a consultation. This was a prospective, randomized study at a large, academic, urban, tertiary care medical center in Chicago. Forty-three emergency medicine (EM) and EM/internal medicine (EM/IM) residents were randomized into two groups, an intervention group and an unstructured group, stratified by postgraduate year (PGY). Intervention group participants received an interactive educational session on the 5 Cs of Consultation, a standardized consultation model. Intervention and unstructured groups placed two simulated consultation phone calls, based on pretested simulated patient cases, to a standardized consultant. Three raters, naive to the consultation model and blinded to group assignments, individually assessed recordings of each call using a seven-item, five-point global rating scale (GRS). Finally, an attending surgeon and an attending psychiatrist each rated respective cases using a single global rating to provide validity evidence for the scale. Residents trained with the 5 Cs model communicated significantly better, regardless of PGY and clinical case. The intervention group had significantly higher mean GRS scores than the unstructured group (4.1 vs. 3.5, F(1,39) = 33.5, p effectiveness of consultation communication from the ED. Residents trained with the 5 Cs of Consultation scored better on consultation assessments compared with untrained residents. Training programs should consider adopting standardized consultation models. © 2012 by the Society for Academic Emergency Medicine.

  18. Transcranial Magnetic Stimulation-coil design with improved focality

    Science.gov (United States)

    Rastogi, P.; Lee, E. G.; Hadimani, R. L.; Jiles, D. C.

    2017-05-01

    Transcranial Magnetic Stimulation (TMS) is a technique for neuromodulation that can be used as a non-invasive therapy for various neurological disorders. In TMS, a time varying magnetic field generated from an electromagnetic coil placed on the scalp is used to induce an electric field inside the brain. TMS coil geometry plays an important role in determining the focality and depth of penetration of the induced electric field responsible for stimulation. Clinicians and basic scientists are interested in stimulating a localized area of the brain, while minimizing the stimulation of surrounding neural networks. In this paper, a novel coil has been proposed, namely Quadruple Butterfly Coil (QBC) with an improved focality over the commercial Figure-8 coil. Finite element simulations were conducted with both the QBC and the conventional Figure-8 coil. The two coil's stimulation profiles were assessed with 50 anatomically realistic MRI derived head models. The coils were positioned on the vertex and the scalp over the dorsolateral prefrontal cortex to stimulate the brain. Computer modeling of the coils has been done to determine the parameters of interest-volume of stimulation, maximum electric field, location of maximum electric field and area of stimulation across all 50 head models for both coils.

  19. Using plot experiments to test the validity of mass balance models employed to estimate soil redistribution rates from 137Cs and 210Pbex measurements

    International Nuclear Information System (INIS)

    Porto, Paolo; Walling, Des E.

    2012-01-01

    Information on rates of soil loss from agricultural land is a key requirement for assessing both on-site soil degradation and potential off-site sediment problems. Many models and prediction procedures have been developed to estimate rates of soil loss and soil redistribution as a function of the local topography, hydrometeorology, soil type and land management, but empirical data remain essential for validating and calibrating such models and prediction procedures. Direct measurements using erosion plots are, however, costly and the results obtained relate to a small enclosed area, which may not be representative of the wider landscape. In recent years, the use of fallout radionuclides and more particularly caesium-137 ( 137 Cs) and excess lead-210 ( 210 Pb ex ) has been shown to provide a very effective means of documenting rates of soil loss and soil and sediment redistribution in the landscape. Several of the assumptions associated with the theoretical conversion models used with such measurements remain essentially unvalidated. This contribution describes the results of a measurement programme involving five experimental plots located in southern Italy, aimed at validating several of the basic assumptions commonly associated with the use of mass balance models for estimating rates of soil redistribution on cultivated land from 137 Cs and 210 Pb ex measurements. Overall, the results confirm the general validity of these assumptions and the importance of taking account of the fate of fresh fallout. However, further work is required to validate the conversion models employed in using fallout radionuclide measurements to document soil redistribution in the landscape and this could usefully direct attention to different environments and to the validation of the final estimates of soil redistribution rate as well as the assumptions of the models employed. - Highlights: ► Soil erosion is an important threat to the long-term sustainability of agriculture.

  20. The use of comparative 137Cs body burden estimates from environmental data/models and whole body counting to evaluate diet models for the ingestion pathway

    International Nuclear Information System (INIS)

    Robison, W.L.; Sun, C.

    1997-01-01

    Rongelap and Utirik Atolls were contaminated on 1 March 1954, by a U.S. nuclear test at Bikini Atoll code named BRAVO. The people at both atolls were removed from their atolls in the first few days after the detonation and were returned to their atolls at different times. Detailed studies have been carried out over the years by Lawrence Livermore National Laboratory (LLNL) to determine the radiological conditions at the atolls and estimate the doses to the populations. The contribution of each exposure pathway and radionuclide have been evaluated. All dose assessments show that the major potential contribution to the estimated dose is 137 Cs uptake via the terrestrial food chain. Brookhaven National Laboratory (BNL) has carried out an extensive whole body counting program at both atolls over several years to directly measure the 137 Cs body burden. Here we compare the estimates of the body burdens from the LLNL environmental method with body burdens measured by the BNL whole body counting method. The combination of the results from both methods is used to evaluate proposed diet models to establish more realistic dose assessments. Very good agreement is achieved between the two methods with a diet model that includes both local and imported foods. Other diet models greatly overestimate the body burdens (i.e., dose) observed by whole body counting. The upper 95% confidence limit of interindividual variability around the population mean value based on the environmental method is similar to that calculated from direct measurement by whole body counting. Moreover, the uncertainty in the population mean value based on the environmental method is in very good agreement with the whole body counting data. This provides additional confidence in extrapolating the estimated doses calculated by the environmental method to other islands and atolls. 46 refs., 8 figs., 5 tabs

  1. Cryogenic structures of superconducting coils for fusion experimental reactor 'ITER'

    International Nuclear Information System (INIS)

    Nakajima, Hideo; Iguchi, Masahide; Hamada, Kazuya; Okuno, Kiyoshi; Takahashi, Yoshikazu; Shimamoto, Susumu

    2013-01-01

    This paper describes both structural materials and structural design of the Toroidal Field (TF) coil and Central Solenoid (CS) for the International Thermonuclear Experimental Reactor (ITER). All the structural materials used in the superconducting coil system of the ITER are austenitic stainless steels. Although 316LN is used in the most parts of the superconducting coil system, the cryogenic stainless steels, JJ1 and JK2LB, which were newly developed by the Japan Atomic Energy Agency (JAEA) and Japanese steel companies, are used in the highest stress area of the TF coil case and the whole CS conductor jackets, respectively. These two materials became commercially available based on demonstration of productivity and weldability of materials, and evaluations of 4 K mechanical properties of trial products including welded parts. Structural materials are classified into five grades depending on stress distribution in the TF coil case. JAEA made an industrial specification for mass production based on the ITER requirements. In order to simplify quality control in mass production, JAEA has used materials specified in the material section of 'Codes for Fusion Facilities - Rules on Superconducting Magnet Structure (2008)' issued by the Japan Society of Mechanical Engineers (JSME) in October 2008, which was established using an extrapolation method of 4 K material strengths from room temperature strength and chemical compositions developed by JAEA. It enables steel suppliers to easily control the quality of products at room temperature. JAEA has already started actual production with several manufacturing companies. The first JJ1 product to be used in the TF coil case and the first JK2LB jackets for CS were completed in October and September 2013, respectively. (author)

  2. Superconducting coil protection

    International Nuclear Information System (INIS)

    Woods, E.L.

    1975-01-01

    The protection system is based on a two-phase construction program. Phase I is the development of a reliable hardwired relay control system with a digital loop utilizing firmware and a microprocessor controller. Phase II is an expansion of the digital loop to include many heretofore unmonitored coil variables. These new monitored variables will be utilized to establish early quench detection and to formulate confirmation techniques of the quench detection mechanism. Established quench detection methods are discussed and a new approach to quench detection is presented. The new circuit is insensitive to external pulsed magnetic fields and the associated induced voltages. Reliability aspects of the coil protection system are discussed with respect to shutdowns of superconducting coil systems. Redundance and digital system methods are presented as related topics

  3. Model of diffusion-convection of 137Cs in marine sediments: a mathematical approach for the assessment of recent sedimentation rates

    International Nuclear Information System (INIS)

    Ferreira, Paulo A.L.; Figueira, Rubens C.L.

    2013-01-01

    Under the perspective of knowing the results of the processes which moves the sedimentary dynamics in coastal environments and assisting works related to the historic of impacts generated in these systems by human occupation, this study shows a practical application of the mathematic-chemical model of diffusion-convection (MDC) of the radionuclide 137 Cs in sedimentary columns for the evaluation of recent sedimentation rates in a Brazilian coastal system. 137 Cs is an artificial radionuclide characterized by its high fission yield and half-life of about 30 years. It is already widely used in this kind of study by reason of its 1963's global peak. The MDC will improve the generated results as the levels of radioactivity of this nuclide are low in the Southern Hemisphere, where this element's main source is the atmospheric fallout from past nuclear explosions, and due to the fact that it is an element with non-negligible vertical mobility. (author)

  4. Multiple model testing using Chernobyl fallout data of I-131 in forage and milk and Cs-137 in forage, milk, beef and grain. Pt. 2

    International Nuclear Information System (INIS)

    1991-03-01

    BIOMOVS is an international study for testing and validating model predictions of the transfer of radionuclides and rare stable elements through the biosphere. The BIOMOVS A4 scenario was designed to test model prediction of the transfer of I-131 and Cs-137 from the atmosphere via pasture vegetation to milk and of the Cs-137 transfer from air to beef (via vegetation) and grain. This document is an appendix to the A4 report. It includes tables and figures of time-integrated results, a summary of a statistical analysis of time-dependent and representative figures of time-dependent results. The quantities to be predicted in this scenario were wet, dry and total deposition (Bq m -2 ) of I-131 and Cs-137, contamination of vegetation (Bq kg -1 d.w.), milk (Bq L -1 ), beef and grain (Bq kg -1 ). While with steady state models only time-integrated results for vegetation, milk and beef could be calculated, these quantities also were requested as time-series from users of dynamic models. A detailed description of the participating models is given in Appendix 3, while all collected observations are documented in Appendix 2 of the A4 report. A diskette with all observed data can be obtained from the Swedish National Institute of Radiation Protection, SSI, or from Harry Koehler, IAEA, Vienna, Austria. For time-integrated P/Os, graphs for all locations and all models and sometimes subsets of these are provided. For time-series, graphs are enclosed for the observations and some model results. These values are calculated across locations and across models for time-integrated predictions and for the P/O of entire time-series and subsets of these for the time-dependent predictions. (au)

  5. Switching transients in the MFTF yin-yang coils

    International Nuclear Information System (INIS)

    Owen, E.W.; Shimer, D.W.

    1982-01-01

    This report is a study of the transients caused by the fast dump of large superconducting coils. Theoretical analysis, computer simulation, and actual measurements are used. Theoretical analysis can only be applied to the simplest of models. In the computer simulations two models are used, one in which the coil is divided into ten segments and another in which a single coil is employed. The circuit breaker that interrupts the current to the power supply, causing a fast dump, is represented by a time and current dependent conductance. Actual measurements are limited to measurements made incidental to the coils' performance tests

  6. Geoinformational modelling of the land use of Polesye and Opolje landscapes in Bryansk region (Russia) under conditions of 137Cs radionuclides contamination

    Science.gov (United States)

    Nenko, Christina; Linnik, Vitaliy; Volkova, Nadezhda

    2015-04-01

    Significant part of Russian Federation was contaminated by 137Cs radionuclides due to Chernobyl disaster in 1986. South-western part of Bryansk region has suffered the most. Study area (the central part of Bryansk region, Polesye and high plains landscapes) is situated outside the officially specified zone of contamination with contamination levels under 1 Ci / km2. Nevertheless, such contamination levels (which are 20 times greater than levels of global fallout) require particular attention as it may contain a threat of the land use and the health of population, living within the territory. Radioactive contamination within the model area was formed as a result of a "dry" deposition from the atmosphere. Consequently, the initial contamination of soil by isotopes 137Cs, unlike the western part of the Bryansk region, was spread relatively equally. The main part of 137Cs (up to 90%) in natural landscapes is contained in the top 5 cm of soil, which itself creates danger of biogeochemical migration from soil to plants. In agricultural landscapes under cultivation 137Cs is uniformly spread within a 20 cm layer of soil and can also come from soil to plants grown in the fields. The area of radioactive contamination that was formed during the period of deposition (late April - early May 1986), is exposed to the processes of secondary redistribution. It is influenced by several factors as topography, vegetation type, proportion of arable soils, soil humidity, soil texture etc. In the presented study there was evaluated the impact of these factors on the secondary redistribution of 137Cs. Sustainable development of agricultural production in the contaminated territories requires managing a number of measures to reduce radiation risks to the population. Regarding this point the greatest threat may be represented by milk production, as well as picking berries and mushrooms. Planning of the sustainable use of the territory requires an evaluation of contamination levels within

  7. Evaluation of sediment and 137Cs redistribution in the Oginosawa River catchment near the Fukushima Dai-ichi Nuclear Power Plant using integrated watershed modeling.

    Science.gov (United States)

    Sakuma, Kazuyuki; Malins, Alex; Funaki, Hironori; Kurikami, Hiroshi; Niizato, Tadafumi; Nakanishi, Takahiro; Mori, Koji; Tada, Kazuhiro; Kobayashi, Takamaru; Kitamura, Akihiro; Hosomi, Masaaki

    2018-02-01

    The Oginosawa River catchment lies 15 km south-west of the Fukushima Dai-ichi nuclear plant and covers 7.7 km 2 . Parts of the catchment were decontaminated between fall 2012 and March 2014 in preparation for the return of the evacuated population. The General-purpose Terrestrial Fluid-flow Simulator (GETFLOWS) code was used to study sediment and 137 Cs redistribution within the catchment, including the effect of decontamination on redistribution. Fine resolution grid cells were used to model local features of the catchment, such as paddy fields adjacent to the Oginosawa River. The simulation was verified using monitoring data for river water discharge rates (r = 0.92), suspended sediment concentrations, and particulate 137 Cs concentrations (r = 0.40). Cesium-137 input to watercourses came predominantly from land adjacent to river channels and forest gullies, e.g. the paddy fields in the Ogi and Kainosaka districts, as the ground in these areas saturates during heavy rain and is easily eroded. A discrepancy between the simulation and monitoring results on the sediment discharge rate following decontamination may be explained by fast erosion occurring after decontamination. Forested areas far from the channels only made a minor contribution to 137 Cs input to watercourses, total erosion of between 0.001 and 0.1 mm from May 2011 to December 2015, as ground saturation is infrequent in these areas. The 2.3-6.9% y -1 decrease in the amount of 137 Cs in forest topsoil over the study period can be explained by radioactive decay (approximately 2.3% y -1 ), along with a migration downwards into subsoil and a small amount of export. The amount of 137 Cs available for release from land adjacent to rivers is expected to be lower in future than compared to this study period, as the simulations indicate a high depletion of inventory from these areas by the end of 2015. However continued monitoring of 137 Cs concentrations in river water over future years is advised, as

  8. Cs-137 migration in soil near NPPs

    International Nuclear Information System (INIS)

    Silant'ev, A.N.; Shkuratova, I.G.; Khatskevich, R.N.

    1984-01-01

    A convective-diffusion model has been employed for describing Cs-137 migration in soil. The migration parameters were determined by comparing the calculated vertical distribution profiles with the experimental ones. The migration parameters dependence on the soil state has been studied. Cs-137 penetration rate was found to be function of the soil type, surface state, soil wetness and orography. The obtained values are presented. A method is suggested for revealing the soil surface contamination by Cs-137 produced during NPP operation with distinguishing it from the global contamination background. For this purpose Cs-137 content in the upper 5 mm soil layer is estimated [ru

  9. Trim coil power supplies

    International Nuclear Information System (INIS)

    Haisler, R.; Peeler, H.; Zajicek, W.

    1985-01-01

    The 18 trim coil power supplies have been constructed and are now in place in the K500 pit and pit mezzanine. Final wiring of the primary power and control power is proceeding along with installation of cooling water supplies. The supplies are expected to be ready for final testing into resistive loads at the beginning of June, 1985

  10. Updating the Design of the Poloidal Field Coils for the ITER Magnet System

    International Nuclear Information System (INIS)

    Yoshida, K.; Takahashi, Y.; Mitchell, N.; Jong, C.; Bessette, D.

    2006-01-01

    The ITER superconducting coil system consists of 18 Toroidal Field coils, six Poloidal Field (PF) coils, six Central Solenoid (CS) modules, 18 Correction Coils and their feeders. The six PF coils are attached to the TF coil cases through flexible plates or sliding supports allowing radial displacements. The PF coils and CS modules provide suitable magnetic fields for plasma shaping and position control. The PF coils use NbTi superconductor, cooled by supercritical helium. This gives a substantial cost saving compared to Nb 3 Sn and the elimination of a reaction heat treatment greatly simplifies the insulation of such large diameter coils. The cable configuration is 6 sub-cables arranged around a central cooling space. The conductors have a heavy square walled stainless steel jacket. The latest parameters of conductor design are evaluated by analysis of the minimum quench energy and hotspot temperature. The PF coils are self supporting as regards the radial magnetic loads. The vertical loads on each PF coil are transmitted to the TF coil cases. Load transmission is through flexible plates for the PF2 to PF5 coils or sliding supports for the PF1 and PF6 coils with fibreslip bearing surfaces. The supports for the PF winding consist of a set of clamping plates and stud bolts. The shape of the clamping plates has been designed to minimize stresses in the winding pack insulation. Bolts are pre-tensioned to keep pressure between the winding pack and clamping plate. Because of the difficulties in replacing the PF coils, the most unreliable component (the coil insulation) is designed with extra redundancy. There are two insulation layers with a thin metal screen in between. By monitoring the voltage of the intermediate screen, it is possible to detect an incipient short, defined as a short in only one of the two insulation layers. Adjustment of the screen voltage level may allow the shot growth to the stopped once it is detected. Alternately the faulty double pancake must

  11. Judd–Ofelt modeling, emission lifetimes and non-radiative relaxation for Er{sup 3+} doped Cs{sub 2}NaYF{sub 6} elpasolite crystals

    Energy Technology Data Exchange (ETDEWEB)

    Loiko, P.A. [ITMO University, 49 Kronverkskiy pr., St. Petersburg 197101 (Russian Federation); Vilejshikova, E.V. [Center for Optical Materials and Technologies (COMT), Belarusian National Technical University, 65/17 Nezavisimosti Ave., Minsk 220013 (Belarus); Khaidukov, N.M. [N.S. Kurnakov Institute of General and Inorganic Chemistry, 31 Leninskii Prospekt, Moscow 119991 (Russian Federation); Méndez-Ramos, J. [Departamento de Física, Universidad de La Laguna, La Laguna 38206, Tenerife (Spain); Mateos, X. [Física i Cristallografia de Materials i Nanomaterials (FiCMA-FiCNA), Universitat Rovira i Virgili (URV), Campus Sescelades, c/ Marcellí Domingo, s/n., Tarragona 43007 (Spain); Yumashev, K.V., E-mail: k.yumashev@tut.by [Center for Optical Materials and Technologies (COMT), Belarusian National Technical University, 65/17 Nezavisimosti Ave., Minsk 220013 (Belarus)

    2017-05-15

    Absorption and emission properties of Er{sup 3+} ions in a cubic elpasolite crystal, Cs{sub 2}NaYF{sub 6}, are modeled within the Judd-Ofelt (J-O) theory. The J-O intensity parameters have been determined: Ω{sub 2} = 0.665, Ω{sub 4} = 0.217 and Ω{sub 6} = 0.029 ×10{sup –20} cm{sup 2}. The elpasolite structure of Cs{sub 2}NaYF{sub 6} containing isolated [YF{sub 6}] polyhedra allows high Er{sup 3+} doping levels up to 100 at% without considerable concentration quenching of luminescence and exceptionally long lifetimes of the excited states (in particular, the radiative lifetimes of the {sup 4}I{sub 13/2} and {sup 4}I{sub 11/2} states are as long as 36.7 ms and 113.4 ms, respectively). It also shows weak non-radiative relaxation. Stimulated-emission cross-sections have been determined for the Er{sup 3+} transitions in Cs{sub 2}NaYF{sub 6} at ~2.7 and ~1.5 μm as well as in the visible spectral range.

  12. Present status in {sup 137}Cs contamination in the marine biota along the Pacific coast of eastern Japan derived from a dynamic biological model simulation following the Fukushima accident - A state and problem in {sup 137}Cs contamination in the marine biota along the Pacific coast of eastern Japan derived from the dynamic biological model simulation after the Fukushima accident - A state and problem in {sup 137}Cs contamination in the marine biota along the Pacific coast of eastern Japan derived from the dynamic biological model simulation after the Fukushima accident

    Energy Technology Data Exchange (ETDEWEB)

    Tateda, Y.; Tsumune, D.; Tsubono, K.; Misumi, K. [Environmental Science Research Laboratory, CRIEPI, 1646, Abiko, Chiba, 270-1194 (Japan); Yamada, M. [Institute of radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Bunkyo, Hirosaki, Aomori, 036-8564 (Japan); Kanda, J.; Ishimaru, T. [Tokyo University of Marine Science and Technology, 4-5-7, Konan, Minato, Tokyo, 108-8477 (Japan)

    2014-07-01

    To understand the radioactive matter contamination of coastal biota in case of accidental release to the environment, the {sup 137}Cs levels in coastal biota around the Fukushima were reconstructed by dynamic model simulating non-equilibrated radioactive Cs transfer between seawater and organisms. Since, there is a disagreement between simulated radioactive Cs levels and observed concentrations in benthic organisms, being possibly attributable to the additional contamination source from sediment environment (Tateda et al. 2013), the {sup 137}Cs levels in organisms habituated not close to the sediment are calculated. Using the reconstructed {sup 137}Cs levels in seawater including atmospheric input and direct leakage after 1/March/2011 till 31/December/2012, {sup 137}Cs levels in sedentary organisms such as macro algae, bivalve and surface swimming plankton feeding fish e.g. as white bait were calculated along the Pacific Ocean coastal area of the Eastern Japan. The simulated temporal space distribution of the {sup 137}Cs levels in macro algae, algae feeding invertebrates, coastal bivalves, were generally agreed in the observed temporal profiles corresponding to the same food habitat organisms collected, while the magnitude of the {sup 137}Cs levels were several times lower than observed concentrations. Since the simulated reconstructed seawater levels are only verified by measured values after direct leakage, thus initial levels before the liquid release may be expected to be higher reconstructed level by simulation. The organisms are continuously exposed to initial contaminated seawater, reflecting actual seawater level increase in seawater, thus there may be possible deficit of initial source estimation in coastal surface water e.g. contribution from fine debris deposition to seaward from hydrogen explosion. In other word as shown in overall pushing up measured level compared to reconstructed level in organism, it also suggests the re-distributed {sup 137}Cs

  13. Simulations of the transport and deposition of 137Cs over Europe after the Chernobyl NPP accident: influence of varying emission-altitude and model horizontal and vertical resolution

    Science.gov (United States)

    Evangeliou, N.; Balkanski, Y.; Cozic, A.; Møller, A. P.

    2013-03-01

    The coupled model LMDzORINCA has been used to simulate the transport, wet and dry deposition of the radioactive tracer 137Cs after accidental releases. For that reason, two horizontal resolutions were deployed and used in the model, a regular grid of 2.5°×1.25°, and the same grid stretched over Europe to reach a resolution of 0.45°×0.51°. The vertical dimension is represented with two different resolutions, 19 and 39 levels, respectively, extending up to mesopause. Four different simulations are presented in this work; the first uses the regular grid over 19 vertical levels assuming that the emissions took place at the surface (RG19L(S)), the second also uses the regular grid over 19 vertical levels but realistic source injection heights (RG19L); in the third resolution the grid is regular and the vertical resolution 39 vertical levels (RG39L) and finally, it is extended to the stretched grid with 19 vertical levels (Z19L). The best choice for the model validation was the Chernobyl accident which occurred in Ukraine (ex-USSR) on 26 May 1986. This accident has been widely studied since 1986, and a large database has been created containing measurements of atmospheric activity concentration and total cumulative deposition for 137Cs from most of the European countries. According to the results, the performance of the model to predict the transport and deposition of the radioactive tracer was efficient and accurate presenting low biases in activity concentrations and deposition inventories, despite the large uncertainties on the intensity of the source released. However, the best agreement with observations was obtained using the highest horizontal resolution of the model (Z19L run). The model managed to predict the radioactive contamination in most of the European regions (similar to Atlas), and also the arrival times of the radioactive fallout. As regards to the vertical resolution, the largest biases were obtained for the 39 layers run due to the increase of

  14. Historical review: another 50th anniversary--new periodicities in coiled coils.

    Science.gov (United States)

    Gruber, Markus; Lupas, Andrei N

    2003-12-01

    In 1953, Francis Crick and Linus Pauling both proposed models of supercoiled alpha helices ('coiled coils') for the structure of keratin. These were the first attempts at modelling the tertiary structure of a protein. Crick emphasized the packing mode of the side-chains ('knobs-into-holes'), which required a periodicity of seven residues over two helical turns (7/2) and a supercoil in the opposite sense of the constituent helices. By contrast, Pauling envisaged a broader set of periodicities (4/1, 7/2, 18/5, 15/4, 11/3) and supercoils of both senses. Crick's model became canonical and the 'heptad repeat' essentially synonymous with coiled coils, but 50 years later new crystal structures and protein sequences show that the less common periodicities envisaged by Pauling also occur in coiled coils, adding a variant packing mode ('knobs-to-knobs') to the standard model. Pauling's laboratory notebooks suggest that he searched unsuccessfully for this packing mode in 1953.

  15. Eccentric Coil Test Facility (ECTF)

    International Nuclear Information System (INIS)

    Burn, P.B.; Walstrom, P.L.; Anderson, W.C.; Marguerat, E.F.

    1975-01-01

    The conceptual design of a facility for testing superconducting coils under some conditions peculiar to tokamak systems is given. A primary element of the proposed facility is a large 25 MJ background solenoid. Discussions of the mechanical structure, the stress distribution and the thermal stability for this coil are included. The systems for controlling the facility and diagnosing test coil behavior are also described

  16. Modular coils: a promising toroidal-reactor-coil system

    International Nuclear Information System (INIS)

    Chu, T.K.; Furth, H.P.; Johnson, J.L.; Ludescher, C.; Weimer, K.E.

    1981-04-01

    The concept of modular coils originated from a need to find reactor-relevant stellarator windings, but its usefulness can be extended to provide an externally applied, additional rotational transform in tokamaks. Considerations of (1) basic principles of modular coils, (2) types of coils, (3) types of configurations (general, helically symmetric, helically asymmetric, with magnetic well, with magnetic hill), (4) types of rotational transform profile, and (5) structure and origin of ripples are given. These results show that modular coils can offer a wide range of vacuum magnetic field configurations, some of which cannot be obtained with the classical stellarator or torsatron coil configuration

  17. Optimization of Coil Element Configurations for a Matrix Gradient Coil.

    Science.gov (United States)

    Kroboth, Stefan; Layton, Kelvin J; Jia, Feng; Littin, Sebastian; Yu, Huijun; Hennig, Jurgen; Zaitsev, Maxim

    2018-01-01

    Recently, matrix gradient coils (also termed multi-coils or multi-coil arrays) were introduced for imaging and B 0 shimming with 24, 48, and even 84 coil elements. However, in imaging applications, providing one amplifier per coil element is not always feasible due to high cost and technical complexity. In this simulation study, we show that an 84-channel matrix gradient coil (head insert for brain imaging) is able to create a wide variety of field shapes even if the number of amplifiers is reduced. An optimization algorithm was implemented that obtains groups of coil elements, such that a desired target field can be created by driving each group with an amplifier. This limits the number of amplifiers to the number of coil element groups. Simulated annealing is used due to the NP-hard combinatorial nature of the given problem. A spherical harmonic basis set up to the full third order within a sphere of 20-cm diameter in the center of the coil was investigated as target fields. We show that the median normalized least squares error for all target fields is below approximately 5% for 12 or more amplifiers. At the same time, the dissipated power stays within reasonable limits. With a relatively small set of amplifiers, switches can be used to sequentially generate spherical harmonics up to third order. The costs associated with a matrix gradient coil can be lowered, which increases the practical utility of matrix gradient coils.

  18. Model testing of radioactive contamination by {sup 90}Sr, {sup 137}Cs and {sup 239,240}Pu of water and bottom sediments in the Techa River (Southern Urals, Russia)

    Energy Technology Data Exchange (ETDEWEB)

    Kryshev, I.I. [Scientific and Production Association ' Typhoon' , 82 Lenin Ave., Obninsk, Kaluga Region, 249038 (Russian Federation)], E-mail: ecomod@obninsk.com; Boyer, P.; Monte, L.; Brittain, J.E.; Dzyuba, N.N.; Krylov, A.L.; Kryshev, A.I.; Nosov, A.V.; Sanina, K.D.; Zheleznyak, M.I. [Scientific and Production Association ' Typhoon' , 82 Lenin Ave., Obninsk, Kaluga Region, 249038 (Russian Federation)

    2009-03-15

    This paper presents results of testing models for the radioactive contamination of river water and bottom sediments by {sup 90}Sr, {sup 137}Cs and {sup 239,240}Pu. The scenario for the model testing was based on data from the Techa River (Southern Urals, Russia), which was contaminated as a result of discharges of liquid radioactive waste into the river. The endpoints of the scenario were model predictions of the activity concentrations of {sup 90}Sr, {sup 137}Cs and {sup 239,240}Pu in water and bottom sediments along the Techa River in 1996. Calculations for the Techa scenario were performed by six participant teams from France (model CASTEAUR), Italy (model MARTE), Russia (models TRANSFER-2, CASSANDRA, GIDRO-W) and Ukraine (model RIVTOX), all using different models. As a whole, the radionuclide predictions for {sup 90}Sr in water for all considered models, {sup 137}Cs for MARTE and TRANSFER-2, and {sup 239,240}Pu for TRANSFER-2 and CASSANDRA can be considered sufficiently reliable, whereas the prediction for sediments should be considered cautiously. At the same time the CASTEAUR and RIVTOX models estimate the activity concentrations of {sup 137}Cs and {sup 239,240}Pu in water more reliably than in bottom sediments. The models MARTE ({sup 239,240}Pu) and CASSANDRA ({sup 137}Cs) evaluated the activity concentrations of radionuclides in sediments with about the same agreement with observations as for water. For {sup 90}Sr and {sup 137}Cs the agreement between empirical data and model predictions was good, but not for all the observations of {sup 239,240}Pu in the river water-bottom sediment system. The modelling of {sup 239,240}Pu distribution proved difficult because, in contrast to {sup 137}Cs and {sup 90}Sr, most of models have not been previously tested or validated for plutonium.

  19. Study on electromagnetic characteristics of the magnetic coupling resonant coil for the wireless power transmission system.

    Science.gov (United States)

    Wang, Zhongxian; Liu, Yiping; Wei, Yonggeng; Song, Yilin

    2018-01-01

    The resonant coil design is taken as the core technology in the magnetic coupling resonant wireless power transmission system, which achieves energy transmission by the coupling of the resonant coil. This paper studies the effect of the resonant coil on energy transmission and the efficiency of the system. Combining a two-coil with a three-coil system, the optimum design method for the resonant coil is given to propose a novel coil structure. First, the co-simulation methods of Pspice and Maxwell are used. When the coupling coefficient of the resonant coil is different, the relationship between system transmission efficiency, output power, and frequency is analyzed. When the self-inductance of the resonant coil is different, the relationship between the performance and frequency of the system transmission is analyzed. Then, two-coil and three-coil structure models are built, and the parameters of the magnetic field of the coils are calculated and analyzed using the finite element method. In the end, a dual E-type simulation circuit model is used to optimize the design of the novel resonance coil. The co-simulation results show that the coupling coefficients of the two-coil, three-coil, and novel coil systems are 0.017, 0.17 and 0.0126, respectively. The power loss of the novel coil is 16.4 mW. There is an obvious improvement in the three-coil system, which shows that the magnetic leakage of the field and the energy coupling are relatively small. The new structure coil has better performance, and the load loss is lower; it can improve the system output power and transmission efficiency.

  20. FRC translation into a compression coil

    International Nuclear Information System (INIS)

    Chrien, R.E.

    1985-01-01

    Several features of the problem of FRC translation into a compression coil are considered. First, the magnitude of the guide field is calculated and found to exceed that which would be applied to a flux conserver. Second, energy conservation is applied to FRC translation from a flux conserver into a compression coil. It is found that a significant temperature decrease is required for translation to be energetically possible. The temperature change depends on the external inductance in the compression circuit. An analogous case is that of a compression region composed of a compound magnet; in this case the temperature change depends on the ratio of inner and outer coil radii. Finally, the kinematics of intermediate translation states are calculated using an ''abrupt transition'' model. It is found, in this model, that the FRC must overcome a potential hill during translation, which requires a small initial velocity

  1. Design of the outer poloidal field coils for ITER

    International Nuclear Information System (INIS)

    Sborchia, C.; Mitchell, N.; Yoshida, K.

    1995-01-01

    The ITER poloidal field (PF) system consists of a central solenoid (CS or PF-1), which is not subject of this paper, and six ring coils using a 40 kA forced flow cooled superconductor. The coils, placed around the toroidal field (TF) system, are used to start-up the plasma with typical ramp-up times of 100 s and burn duration of 1000 s. They also provide control and shaping of the plasma, with small, frequent current variations on a 1-5 s time scale. The magnetic field produced by the coils ranges from about 4.5 to 8 T and the AC losses in the conductor are significant: the largest coils require cooling path lengths up to 1000 m as well as the use of 2 in-hand winding. The field level and high thermal loads make the use of Nb 3 Sn strand attractive. This paper describes the basic design of the six ring (outer) coils developed by the ITER Joint Central Team in collaboration with the four Home Teams. The coil structural material is provided by a thick conductor jacket and by a bonded insulation system. The forces acting on the coils during typical operational scenarios and plasma disruption/vertical instabilities have been evaluated: radial forces are self-reacted by hoop stresses in the ring coil, with tensile stresses up to 300 MPa in the conductor jacket, and the vertical forces are resisted by a discrete support system, with shear stresses up to 10 MPa in the insulation. (orig./WL)

  2. Solutions for Safe Hot Coil Evacuation and Coil Handling in Case of Thick and High Strength Steel

    Directory of Open Access Journals (Sweden)

    Sieberer Stefan

    2016-01-01

    Full Text Available Currently hot rolling plants are entering the market segment for thick gauges and high strength steel grades where the elastic bending property of the strip leads to internal forces in the coil during coiling operation. The strip tends to open. Primetals is investigating several possibilities to facilitate safe coil evacuation and coil handling under spring-back conditions. The contribution includes finite element models of such mechanical solutions. Results of parameter variation and stability limits of case studies are presented in the paper.

  3. Multiple model testing using Chernobyl fallout data of I-131 in forage and milk and Cs-137 in forage, milk, beef and grain. Pt. 1

    International Nuclear Information System (INIS)

    Koehler, H.; Peterson, S.R.; Owen Hoffman, F.

    1991-03-01

    Comprehensive measurements of I-131 and Cs-137 in the environment after the Chernobyl accident provided a unique opportunity for the collection of environmental transfer data sets. These come from 13 locations in the northern hemisphere which experienced levels of contamination that spanned approximately three orders of magnitude. Data have been compiled for radionuclide concentrations in air, rain, pasture vegetation, milk, beef and grain. In addition background information has been collated for factors such as prevailing meteorological conditions, location description, and local agricultural practices. Participants were asked to predict radionuclide concentrations in forage, milk, beef and grain from radionuclide concentrations in air, the daily amounts of precipitation and other pertinent information. This was a blind test in that the locations to which the input data referred were not revealed to the participants until after they had submitted their predictions. Twenty-three models were involved in the study. This report compares observations and predictions for deposition, time- integrated concentrations in forage, milk, beef and grain, to help assess understanding of individual processes, time-dependent concentrations in forage, milk and beef. In general, predictions of time-integrated concentration of I-131 and Cs-137 in forage, milk (normalized for forage) and beef are within a factor of 10 of the observations. About 50% of the predictions of I-131 and Cs-137 in forage and just over 30% of the predictions of those nuclides in milk (normalized for forage) fall within a factor of 2 of the observations. Documentation of the measurements, models, methods of analysis and model results is presented in the appendices. (au) (75 refs.)

  4. Split-coil-system SULTAN

    International Nuclear Information System (INIS)

    Vecsey, G.

    1992-08-01

    The high field superconductor test facility SULTAN started operation successfully in May 1992. Originally designed for testing full scale conductors for the large magnets of the next generation fusion reactors, the SULTAN facility installed at PSI (Switzerland) was designed as a common venture of three European Laboratories: ENEA (Italy), ECN (Netherlands) and PSI, and built by ENEA and PSI in the framework of the Euratom Fusion Technology Program. Presently the largest facility in the world, with its superconducting split coil system generating 11 Tesla in a 0.6 m bore, it is ready now for testing superconductor samples with currents up to 50 kA at variable cooling conditions. Similar tests can be arranged also for other applications. SULTAN is offered by the European Community as a contribution to the worldwide cooperation for the next step of fusion reactor development ITER. First measurements on conductor developed by CEA (Cadarache) are now in progress. Others like those of ENEA and CERN will follow. For 1993, a test of an Italian 12 TZ model coil for fusion application is planned. SULTAN is a worldwide unique facility marking the competitive presence of Swiss technology in the field of applied superconductivity research. Based on development and design of PSI, the high field Nb 3 Sn superconductors and coils were fabricated at the works of Kabelwerke Brugg and ABB, numerous Swiss companies contributed to the success of this international effort. Financing of the Swiss contribution of SULTAN was made available by NEFF, BEW, BBW, PSI and EURATOM. (author) figs., tabs., 20 refs

  5. Spiral versus J-shaped coils for neurovascular embolisation - an in-vitro study

    International Nuclear Information System (INIS)

    Sugiu, K.; Tokunaga, K.; Mandai, S.; Martin, J.B.; Jean, B.; Ruefenacht, D.A.

    2003-01-01

    Our purpose was to compare the characteristics of J-shaped detachable platinum coils with those of spiral coils in in-vitro vascular models. J-shaped coils consist of distal semicircular and proximal straight segments, the latter extending for most of the length of the coil. Spiral coils have a helical shape memory and are thus limited in expansion. In in-vitro silicone vascular models simulating intracranial aneurysms and dural arteriovenous fistulae, we compared J-shaped and spiral coils with regard to ease of delivery, anchoring and folding patterns, and stability in various types of vascular lumen. Delivery and retrieval were comparable. In large and irregular aneurysms and venous sinuses, J-shaped coils could form a more complex basket which conformed to the shape of the vascular cavity. The J-shaped coil was always in contact with the vessel wall. In wide-necked aneurysms, coil protrusion was more frequent with J-shaped coils, while spiral coils tended to stay compact and circular. Arteries were occluded in a shorter segment with spiral coils. J-shaped coils were safe and superior for large and irregular aneurysms or sinuses. Spiral coils were preferable for spherical aneurysms and segmental occlusion of arteries. (orig.)

  6. Development of a Mass Transfer Model and Its Application to the Behavior of the Cs, Sr, Ba, and Oxygen ions in an Electrolytic Reduction Process for SF

    International Nuclear Information System (INIS)

    Park, Byung Heung; Kang, Dae Seung; Seo, Chung Seok; Park, Seong Won

    2005-01-01

    Isotopes of alkali and alkaline earth metals (AM and AEM) are the main contributors to the heat load and the radiotoxicity of spent fuel (SF). These components are separated from the SF and dissolved in a molten LiCl in an electrolytic reduction process. A mass transfer model is developed to describe the diffusion behavior of Cs, Sr, and Ba in the SF into the molten salt. The model is an analytical solution of Fick's second law of diffusion for a cylinder which is the shape of a cathode in the electrolytic reduction process. And the model is also applied to depict the concentration profile of the oxygen ion which is produced by the electrolysis of Li 2 O. The regressed diffusion coefficients of the model correlating the experimentally measured data are evaluated to be greater in the order of Ba, Cs, and Sr for the metal ions and the diffusion of the oxygen ion is slower than the metal ions which implies that different mechanisms govern the diffusion of the metal ions and the oxygen ions in a molten LiCl.

  7. Results from a model system of superconducting solenoids and phase shifting bridge for pulsed power studies for proposed tokamak EF coils

    International Nuclear Information System (INIS)

    Fuja, R.E.; Kustom, R.L.; Smith, R.P.

    1977-01-01

    A matched pair of superconducting solenoids and a phase-shifting bridge circuit has been constructed to study energy storage and transfer for application to tokamak EF coils. The intrinsically stable solenoids, each with 4 H self-inductance, incorporate sufficient cooling to allow charging at several hundred volts, corresponding to B approximately equal 1 T/sec. The three-phase inductor-convertor capacitive bridge network operating at up to 150 V rms transfers energy reversibly and at controllable rates from the storage coil to the load coil

  8. Results from a model system of superconducting solenoids and phase shifting bridge for pulsed power studies for proposed tokamak EF coils

    International Nuclear Information System (INIS)

    Fuja, R.E.; Kustom, R.L.; Smith, R.P.

    1977-01-01

    A matched pair of superconducting solenoids and a phase-shifting bridge circuit has been constructed to study energy storage and transfer for application to tokamak EF coils. The intrinsically stable solenoids, each with 4 H self-inductance, incorporate sufficient cooling to allow charging at several hundred volts, corresponding to B = 1 T/sec. The three-phase inductor-convertor capacitive bridge network operating at up to 150 V rms transfers energy reversibly and at controllable rates from the storage coil to the load coil

  9. Supporting device for Toroidal coils

    International Nuclear Information System (INIS)

    Araki, Takao.

    1985-01-01

    Purpose: To reduce the response of a toroidal coil supporting device upon earthquakes and improve the earthquake proofness in a tokamak type thermonuclear device. Constitution: Structural materials having large longitudinal modulus and enduring great stresses, for example, stainless steels are used as the toroidal coil supporting legs and heat insulating structural materials are embedded in a nuclear reactor base mats below the supporting legs. Furthermore, heat insulating concretes are spiked around the heat insulating structural materials to prevent the intrusion of heat to the toroidal coils. The toroidal coils are kept at cryogenic state and superconductive state for the conductors. In this way, the period of proper vibrations of the toroidal coils and the toroidal coil supporting structures can be shortened thereby decreasing the seismic response. Furthermore, since the strength of the supporting legs is increased, the earthquake proofness of the coils can be improved. (Kamimura, M.)

  10. Inductance and resistance measurement method for vessel detection and coil powering in all-surface inductive heating systems composed of outer squircle coils

    Science.gov (United States)

    Kilic, Veli Tayfun; Unal, Emre; Demir, Hilmi Volkan

    2017-05-01

    In this work, we investigate a method proposed for vessel detection and coil powering in an all-surface inductive heating system composed of outer squircle coils. Besides conventional circular coils, coils with different shapes such as outer squircle coils are used for and enable efficient all-surface inductive heating. Validity of the method, which relies on measuring inductance and resistance values of a loaded coil at different frequencies, is experimentally demonstrated for a coil with shape different from conventional circular coil. Simple setup was constructed with a small coil to model an all-surface inductive heating system. Inductance and resistance maps were generated by measuring coil's inductance and resistance values at different frequencies loaded by a plate made of different materials and located at various positions. Results show that in an induction hob for various coil geometries it is possible to detect a vessel's presence, to identify its material type and to specify its position on the hob surface by considering inductance and resistance of the coil measured on at least two different frequencies. The studied method is important in terms of enabling safe, efficient and user flexible heating in an all-surface inductive heating system by automatically detecting the vessel's presence and powering on only the coils that are loaded by the vessel with predetermined current levels.

  11. Initial spread of "1"3"7Cs from the Fukushima Dai-ichi Nuclear Power Plant over the Japan continental shelf. A study using a high-resolution, global-coastal nested ocean model

    International Nuclear Information System (INIS)

    Lai, Z.; Chen, C.; Lin, H.; Shanghai Ocean Univ.; Beardsley, R.; Ji, R.; Shanghai Ocean Univ.; Sasaki, J.; Lin, J.

    2013-01-01

    The 11 March 2011 tsunami triggered by the M9 and M7.9 earthquakes off the Tohoku coast destroyed facilities at the Fukushima Dai-ichi Nuclear Power Plant (FNPP) leading to a significant long-term flow of the radionuclide "1"3"7Cs into coastal waters. A high-resolution, global-coastal nested ocean model was first constructed to simulate the 11 March tsunami and coastal inundation. Based on the model's success in reproducing the observed tsunami and coastal inundation, model experiments were then conducted with differing grid resolution to assess the initial spread of "1"3"7Cs over the eastern shelf of Japan. The "1"3"7Cs was tracked as a conservative tracer (without radioactive decay) in the three-dimensional model flow field over the period of 26 March-31 August 2011. The results clearly show that for the same "1"3"7Cs discharge, the model-predicted spreading of "1"3"7Cs was sensitive not only to model resolution but also the FNPP seawall structure. A coarse-resolution (∝2 km) model simulation led to an overestimation of lateral diffusion and thus faster dispersion of "1"3"7Cs from the coast to the deep ocean, while advective processes played a more significant role when the model resolution at and around the FNPP was refined to ∝5 m. By resolving the pathways from the leaking source to the southern and northern discharge canals, the high-resolution model better predicted the "1"3"7Cs spreading in the inner shelf where in situ measurements were made at 30 km off the coast. The overestimation of "1"3"7Cs concentration near the coast is thought to be due to the omission of sedimentation and biogeochemical processes as well as uncertainties in the amount of "1"3"7Cs leaking from the source in the model. As a result, a biogeochemical module should be included in the model for more realistic simulations of the fate and spreading of "1"3"7Cs in the ocean.

  12. Initial spread of {sup 137}Cs from the Fukushima Dai-ichi Nuclear Power Plant over the Japan continental shelf. A study using a high-resolution, global-coastal nested ocean model

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Z. [Sun Yat-Sen Univ., Guangzhou (China). School of Marine Sciences; Univ. of Massachusetts-Dartmouth, New Bedford, MA (United States). School for Marine Science and Technology; Key Laboratory of Marine Resources and Coastal Engineering in Guangdong Province, Guangzhou (China); Chen, C.; Lin, H. [Univ. of Massachusetts-Dartmouth, New Bedford, MA (United States). School for Marine Science and Technology; Shanghai Ocean Univ. (China). International Center for Marine Studies; Beardsley, R. [Woods Hole Oceanographic Institution, Woods Hole, MA (United States). Dept. of Physical Oceanography; Ji, R. [Woods Hole Oceanographic Institution, Woods Hole, MA (United States). Dept. of Biology; Shanghai Ocean Univ. (China). International Center for Marine Studies; Sasaki, J. [The Univ. of Tokyo, Kashiwa (Japan). Dept. of Socio-Cultural Environmental Studies; Lin, J. [Woods Hole Oceanographic Institution, Woods Hole, MA (United States). Dept. of Geology and Geophysics

    2013-07-01

    The 11 March 2011 tsunami triggered by the M9 and M7.9 earthquakes off the Tohoku coast destroyed facilities at the Fukushima Dai-ichi Nuclear Power Plant (FNPP) leading to a significant long-term flow of the radionuclide {sup 137}Cs into coastal waters. A high-resolution, global-coastal nested ocean model was first constructed to simulate the 11 March tsunami and coastal inundation. Based on the model's success in reproducing the observed tsunami and coastal inundation, model experiments were then conducted with differing grid resolution to assess the initial spread of {sup 137}Cs over the eastern shelf of Japan. The {sup 137}Cs was tracked as a conservative tracer (without radioactive decay) in the three-dimensional model flow field over the period of 26 March-31 August 2011. The results clearly show that for the same {sup 137}Cs discharge, the model-predicted spreading of {sup 137}Cs was sensitive not only to model resolution but also the FNPP seawall structure. A coarse-resolution (∝2 km) model simulation led to an overestimation of lateral diffusion and thus faster dispersion of {sup 137}Cs from the coast to the deep ocean, while advective processes played a more significant role when the model resolution at and around the FNPP was refined to ∝5 m. By resolving the pathways from the leaking source to the southern and northern discharge canals, the high-resolution model better predicted the {sup 137}Cs spreading in the inner shelf where in situ measurements were made at 30 km off the coast. The overestimation of {sup 137}Cs concentration near the coast is thought to be due to the omission of sedimentation and biogeochemical processes as well as uncertainties in the amount of {sup 137}Cs leaking from the source in the model. As a result, a biogeochemical module should be included in the model for more realistic simulations of the fate and spreading of {sup 137}Cs in the ocean.

  13. High voltage investigations for ITER coils

    International Nuclear Information System (INIS)

    Fink, S.; Fietz, W.H.

    2006-01-01

    The superconducting ITER magnets will be excited with high voltage during operation and fast discharge. Because the coils are complex systems the internal voltage distribution can differ to a large extent from the ideal linear voltage distribution. In case of fast excitations internal voltages between conductor and radial plate of a TF coil can be even higher than the terminal voltage of 3.5 kV to ground which appears during a fast discharge without a fault. Hence the determination of the transient voltage distribution is important for a proper insulation co-ordination and will provide a necessary basis for the verification of the individual insulation design and the choice of test voltages and waveforms. Especially the extent of internal overvoltages in case of failures, e. g. malfunction of discharge units and / or arcing is of special interest. Transient calculations for the ITER TF coil system have been performed for fast discharge and fault scenarios to define test voltages for ITER TF. The conductor and radial plate insulation of the ITER TF Model Coil were exposed at room temperature to test voltages derived from the results from these calculations. Breakdown appeared during the highest AC voltage step. A fault scenario for the TF fast discharge system is presented where one fault triggers a second fault, leading to considerable voltage stress. In addition a FEM model of Poloidal Field Coil 3 for the determination of the parameters of a detailed network model is presented in order to prepare detailed investigations of the transient voltage behaviour of the PF coils. (author)

  14. Performance of trim coils made by a novel method

    International Nuclear Information System (INIS)

    Wanderer, P.; Anerella, M.; Cottingham, J.; Ganetis, G.; Garber, M.; Ghosh, A.; Goodzeit, C.; Greene, A.; Gupta, R.; Herrera, J.; Kahn, S.; Kelly, E.; Meade, A.; Morgan, G.; Muratore, J.; Prodell, A.; Rehak, M.; Rohrer, E.P.; Sampson, W.; Shutt, R.; Skaritka, J.; Thompson, P.; Willen, E.

    1991-01-01

    A precision, automated method of manufacturing trim coils based on printed circuit technology has been developed. Excellent quench performance and increased radiation resistance have been achieved in recently-tested models of sextupole trim coils developed for operation inside 40 mm-aperture SSC Main Collider dipoles. 6 refs., 2 figs

  15. Predicting oil and gas compositional yields via chemical structure-chemical yield modeling (CS-CYM): Part 1 - Concepts and implementation

    Energy Technology Data Exchange (ETDEWEB)

    Freund, H.; Walters, C.C.; Kelemen, S.R.; Siskin, M.; Gorbaty, M.L.; Curry, D.J.; Bence, A.E. [ExxonMobil Research & Engineering Co., Annandale, NJ (United States)

    2007-07-01

    We have developed a method to calculate the amounts and composition of products resulting from the thermal decomposition of a solid complex carbonaceous material. This procedure provides a means of using laboratory measurements of complex carbonaceous solids to construct a representative model of its chemical structure (CS) that is then coupled with elementary reaction pathways to predict the chemical yield (CY) upon thermal decomposition. Data from elemental analysis, H, N, O, S, solid state {sup 13}C NMR, X-ray photoelectron spectroscopy (XPS), sulfur X-ray absorption structure spectroscopy (XANES), and pyrolysis-gas chromatography (GC) are used to constrain the construction of core molecular structures representative of the complex carbonaceous material. These core structures are expanded stochastically to describe large macromolecules ({gt} 10{sup 6} cores with similar to 10{sup 6} atoms) with bulk properties that match the experimental results. Gas, liquid and solid product yields, resulting from thermal decomposition, are calculated by identifying reactive functional groups within the CS stochastic ensemble and imposing a reaction network constrained by fundamental thermodynamics and kinetics. An expulsion model is added to the decomposition model to calculate the chemical products in open and closed systems. Product yields may then be predicted under a wide range of time-temperature conditions used in rapid laboratory pyrolysis experiments, refinery processes, or geologic maturation.

  16. A test of hypothetical hill-slope-gully-streambed soil redistribution model using fallout cs-137 a first use of the technique in pakistan

    International Nuclear Information System (INIS)

    Ahmad, M.; Sheikh, M.R.; Akram, W.; Ali, M.; Iqbal, N.

    2007-07-01

    Soil degradation by water erosion, which is further responsible for sedimentation in the conveyance systems and reservoirs, is a matter of growing concern in Pakistan. Caesium-137, a fallout radioisotope produced from atmospheric nuclear weapon tests, has become a well-established radiotracer of soil movement. To assess the potential for application of caesium-137 as an indicator of soil erosion and sedimentation, a hypothetical hill slope-gully-streambed redistribution model was tested in Mangla Watershed, Pakistan, as a first use of the technique in the country. The results indicate that the soil redistribution along the different components follows the hypothetical model, with severe net soil loss (sheet erosion) at the hill-slope, no labeling of gully head, and high sedimentation on the streambed. The reference inventory of 137CS obtained by scraper plate (4380 Bq m-2 was in agreement with the mean value of bulk cores (i.e. 3945 +- 457 Bq m-2). The net soil loss along the hill slope estimated by the profile distribution model was 17.2 t ha-1 yr-l. The sedimentation rate in the main stream was more before the year 1974 (8 cm yr-l) than afterwards reducing to 5.9 cm yr-1 due to re-vegetation. The 137CS technique proved to be less time consuming in the provision of information on soil redistribution rates than direct measurement would have been and can be used to assess watershed management practices in Pakistan. (author)

  17. Test results for a Bi-2223 HTS racetrack coil for generator applications

    International Nuclear Information System (INIS)

    Salasoo, L.; Herd, K.G.; Laskaris, E.T.; Hart, H.R. Jr.; Chari, M.V.K.

    1996-01-01

    Testing, results and analysis of a Bi-2223 model superconducting generator coil produced under the DOE Superconductivity Partnership Initiative are presented. The test arrangement enables coil energization with dc and transient currents over a range of operating temperatures to explore coil performance under conditions analogous to those that would be experienced by a superconducting generator field coil. Analytical calculations of coil ac and ohmic losses and temperature rise compare well with experimental measurements. Good performance is predicted for a typical 3-phase fault condition. Coil steady state and transient performance can be predicted with confidence for full scale superconductor application

  18. Inverse approach for determination of the coils location during magnetic stimulation

    International Nuclear Information System (INIS)

    Marinova, Iliana; Kovachev, Ludmil

    2002-01-01

    An inverse approach using neural networks is extended and applied for determination of coils location during magnetic stimulation. The major constructions of magnetic stimulation coils have been investigated. The electric and magnetic fields are modelled using finite element method and integral equation method. The effects of changing the construction of coils and the frequency to the effect of magnetic stimulation are analysed. The results show that the coils for magnetic stimulation characterize with different focality and magnetic field concentration. The proposed inverse approach using neural networks is very useful for determination the spatial position of the stimulation coils especially when the location of the coil system is required to be changed dynamically. (Author)

  19. Mapping the electron correlation onto a model Hamiltonian for Cs/GaAs(110): a Mott-Hubbard insulator at quarter filling

    CERN Document Server

    Chen Chang Feng

    1998-01-01

    We have constructed an effective model Hamiltonian in the Hubbard formalism for the Cs/GaAs(110) surface at quarter-monolayer coverage with all of the parameters extracted from constrained local-density-approximation (LDA) pseudopotential calculations. The single-particle excitation spectrum of the model has been calculated using an exact-diagonalization technique to help determine the relevant interaction terms. It is shown that the intersite interaction between the nearest-neighbour Ga sites plays the key role in determining the insulating nature of the system and must be included in the model, in contrast to suggestions of some previous work. Our results show that a reliable mapping of LDA results onto an effective model Hamiltonian can be achieved by combining constrained LDA calculations for the Hamiltonian parameters and many-body calculations of the single-particle excitation spectrum for identifying relevant interaction terms. (author)

  20. Acoustic rainbow trapping by coiling up space

    KAUST Repository

    Ni, Xu

    2014-11-13

    We numerically realize the acoustic rainbow trapping effect by tapping an air waveguide with space-coiling metamaterials. Due to the high refractive-index of the space-coiling metamaterials, our device is more compact compared to the reported trapped-rainbow devices. A numerical model utilizing effective parameters is also calculated, whose results are consistent well with the direct numerical simulation of space-coiling structure. Moreover, such device with the capability of dropping different frequency components of a broadband incident temporal acoustic signal into different channels can function as an acoustic wavelength division de-multiplexer. These results may have potential applications in acoustic device design such as an acoustic filter and an artificial cochlea.

  1. Acoustic rainbow trapping by coiling up space

    KAUST Repository

    Ni, Xu; Wu, Ying; Chen, Ze-Guo; Zheng, Li-Yang; Xu, Ye-Long; Nayar, Priyanka; Liu, Xiao-Ping; Lu, Ming-Hui; Chen, Yan-Feng

    2014-01-01

    We numerically realize the acoustic rainbow trapping effect by tapping an air waveguide with space-coiling metamaterials. Due to the high refractive-index of the space-coiling metamaterials, our device is more compact compared to the reported trapped-rainbow devices. A numerical model utilizing effective parameters is also calculated, whose results are consistent well with the direct numerical simulation of space-coiling structure. Moreover, such device with the capability of dropping different frequency components of a broadband incident temporal acoustic signal into different channels can function as an acoustic wavelength division de-multiplexer. These results may have potential applications in acoustic device design such as an acoustic filter and an artificial cochlea.

  2. Zero current measurements using the Rogowski coil

    International Nuclear Information System (INIS)

    Gregor, J.; Jakubova, I.; Kadlec, P.; Senk, J.; Vavra, Z.

    1997-01-01

    The zero current measurements using the Rogowski coil carried out on the model of the extinguishing chamber of hv SF 6 circuit breaker with self-flow generation are presented in the paper. The time course of the post-arc current obtained by numerical integration of the measured induced voltage of the Rogowski coil gives information not only about the value of the residual current after the successful interruption but also about the current changes connected with the dynamic behaviour of the arc during its quenching. (author)

  3. Improving CS regulations.

    Energy Technology Data Exchange (ETDEWEB)

    Nesse, R.J.; Scheer, R.M.; Marasco, A.L.; Furey, R.

    1980-10-01

    President Carter issued Executive Order 12044 (3/28/78) that required all Federal agencies to distinguish between significant and insignificant regulations, and to determine whether a regulation will result in major impacts. This study gathered information on the impact of the order and the guidelines on the Office of Conservation and Solar Energy (CS) regulatory practices, investigated problems encountered by the CS staff when implementing the order and guidelines, and recommended solutions to resolve these problems. Major tasks accomplished and discussed are: (1) legislation, Executive Orders, and DOE Memoranda concerning Federal administrative procedures relevant to the development and analysis of regulations within CS reviewed; (2) relevant DOE Orders and Memoranda analyzed and key DOE and CS staff interviewed in order to accurately describe the current CS regulatory process; (3) DOE staff from the Office of the General Counsel, the Office of Policy and Evaluation, the Office of the Environment, and the Office of the Secretary interviewed to explore issues and problems encountered with current CS regulatory practices; (4) the regulatory processes at five other Federal agencies reviewed in order to see how other agencies have approached the regulatory process, dealt with specific regulatory problems, and responded to the Executive Order; and (5) based on the results of the preceding four tasks, recommendations for potential solutions to the CS regulatory problems developed. (MCW)

  4. Plasmodium vivax antigen discovery based on alpha-helical coiled coil protein motif.

    Directory of Open Access Journals (Sweden)

    Nora Céspedes

    Full Text Available Protein α-helical coiled coil structures that elicit antibody responses, which block critical functions of medically important microorganisms, represent a means for vaccine development. By using bioinformatics algorithms, a total of 50 antigens with α-helical coiled coil motifs orthologous to Plasmodium falciparum were identified in the P. vivax genome. The peptides identified in silico were chemically synthesized; circular dichroism studies indicated partial or high α-helical content. Antigenicity was evaluated using human sera samples from malaria-endemic areas of Colombia and Papua New Guinea. Eight of these fragments were selected and used to assess immunogenicity in BALB/c mice. ELISA assays indicated strong reactivity of serum samples from individuals residing in malaria-endemic regions and sera of immunized mice, with the α-helical coiled coil structures. In addition, ex vivo production of IFN-γ by murine mononuclear cells confirmed the immunogenicity of these structures and the presence of T-cell epitopes in the peptide sequences. Moreover, sera of mice immunized with four of the eight antigens recognized native proteins on blood-stage P. vivax parasites, and antigenic cross-reactivity with three of the peptides was observed when reacted with both the P. falciparum orthologous fragments and whole parasites. Results here point to the α-helical coiled coil peptides as possible P. vivax malaria vaccine candidates as were observed for P. falciparum. Fragments selected here warrant further study in humans and non-human primate models to assess their protective efficacy as single components or assembled as hybrid linear epitopes.

  5. Coiled-coil forming peptides for the induction of silver nanoparticles

    International Nuclear Information System (INIS)

    Božič Abram, Sabina; Aupič, Jana; Dražić, Goran; Gradišar, Helena; Jerala, Roman

    2016-01-01

    Biopolymers with defined sequence patterns offer an attractive alternative for the formation of silver nanoparticle (AgNP). A set of coiled-coil dimer forming peptides was tested for their AgNP formation ability. Seventeen of those peptides mediated the formation of AgNPs in aqueous solution at neutral pH, while the formation of a coiled-coil dimer inhibited the nanoparticle generation. A QSAR regression model on the relationship between sequence and function suggests that in this peptide type the patterns KXQQ and KXEE are favorable, whereas Ala residues appear to have an inhibitory effect. UV–VIS spectra of the obtained nanoparticles gave a peak at around 420 nm, typical for AgNPs in the size range around 40 nm, which was confirmed by dynamic light scattering and transmission electron microscopy. Peptide-induced AgNPs exhibited good antibacterial activity, even after a 15 min contact time, while they had low toxicity to human cells at the same concentrations. These results show that our designed peptides generate AgNPs with antibacterial activity at mild conditions and might be used for antibacterial coatings. - Highlights: • 17 of the 30 tested coiled-coil forming peptides induce AgNP formation. • Coiled-coil dimer formation suppresses AgNP generation of individual peptides. • Size of the peptide-induced silver nanoparticles is around 40 nm. • QSAR analysis points to the importance of KXQQ and KXEE motifs for AgNP generation. • Peptide-induced silver nanoparticles exhibit antibacterial activity.

  6. Coiled-coil forming peptides for the induction of silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Božič Abram, Sabina [Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); Graduate School of Biomedicine, University of Ljubljana, Ljubljana 1000 (Slovenia); Aupič, Jana [Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); Doctoral Programme in Chemical Sciences, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana 1000 (Slovenia); Dražić, Goran [Laboratory for Materials Chemistry, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); Gradišar, Helena [Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); EN-FIST, Centre of Excellence, Trg Osvobodilne fronte 13, Ljubljana 1000 (Slovenia); Jerala, Roman, E-mail: roman.jerala@ki.si [Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); EN-FIST, Centre of Excellence, Trg Osvobodilne fronte 13, Ljubljana 1000 (Slovenia)

    2016-04-08

    Biopolymers with defined sequence patterns offer an attractive alternative for the formation of silver nanoparticle (AgNP). A set of coiled-coil dimer forming peptides was tested for their AgNP formation ability. Seventeen of those peptides mediated the formation of AgNPs in aqueous solution at neutral pH, while the formation of a coiled-coil dimer inhibited the nanoparticle generation. A QSAR regression model on the relationship between sequence and function suggests that in this peptide type the patterns KXQQ and KXEE are favorable, whereas Ala residues appear to have an inhibitory effect. UV–VIS spectra of the obtained nanoparticles gave a peak at around 420 nm, typical for AgNPs in the size range around 40 nm, which was confirmed by dynamic light scattering and transmission electron microscopy. Peptide-induced AgNPs exhibited good antibacterial activity, even after a 15 min contact time, while they had low toxicity to human cells at the same concentrations. These results show that our designed peptides generate AgNPs with antibacterial activity at mild conditions and might be used for antibacterial coatings. - Highlights: • 17 of the 30 tested coiled-coil forming peptides induce AgNP formation. • Coiled-coil dimer formation suppresses AgNP generation of individual peptides. • Size of the peptide-induced silver nanoparticles is around 40 nm. • QSAR analysis points to the importance of KXQQ and KXEE motifs for AgNP generation. • Peptide-induced silver nanoparticles exhibit antibacterial activity.

  7. Strong contributions from vertical triads to helix-partner preferences in parallel coiled coils.

    Science.gov (United States)

    Steinkruger, Jay D; Bartlett, Gail J; Woolfson, Derek N; Gellman, Samuel H

    2012-09-26

    Pairing preferences in heterodimeric coiled coils are determined by complementarities among side chains that pack against one another at the helix-helix interface. However, relationships between dimer stability and interfacial residue identity are not fully understood. In the context of the "knobs-into-holes" (KIH) packing pattern, one can identify two classes of interactions between side chains from different helices: "lateral", in which a line connecting the adjacent side chains is perpendicular to the helix axes, and "vertical", in which the connecting line is parallel to the helix axes. We have previously analyzed vertical interactions in antiparallel coiled coils and found that one type of triad constellation (a'-a-a') exerts a strong effect on pairing preferences, while the other type of triad (d'-d-d') has relatively little impact on pairing tendencies. Here, we ask whether vertical interactions (d'-a-d') influence pairing in parallel coiled-coil dimers. Our results indicate that vertical interactions can exert a substantial impact on pairing specificity, and that the influence of the d'-a-d' triad depends on the lateral a' contact within the local KIH motif. Structure-informed bioinformatic analyses of protein sequences reveal trends consistent with the thermodynamic data derived from our experimental model system in suggesting that heterotriads involving Leu and Ile are preferred over homotriads involving Leu and Ile.

  8. Model for deposition and long-term disposition of 134Cs-labeled fused aluminosilicate particles inhaled by guinea pigs

    International Nuclear Information System (INIS)

    Snipes, M.B.; McClellan, R.O.

    1986-01-01

    When considering which laboratory animal species to use in inhalation studies, it is important to evaluate the similarities and differences in deposition and fate of the inhaled materials in various laboratory animals compared with humans. Beagle dogs have deposition and clearance patterns of inhaled particles similar to humans. However, some studies require smaller laboratory animals to be cost effective or to allow an adequate number of animals to address the scientific questions. This study evaluated the deposition and clearance of a relatively insoluble aerosol inhaled by guinea pigs. The test aerosol was monodisperse 134 Cs-labeled fused aluminosilicate particles inhaled during 75 minute inhalation exposure. The guinea pigs had deposition similar to rats but respiratory tract retention and clearance patterns were similar to dogs and humans. 5 references, 2 figures, 1 table

  9. Comparison of Radioecological Processes on Examples of Villages Polluted by 137Cs and 90Sr Appreciated on the Box Model Method

    International Nuclear Information System (INIS)

    Matvjejeva, I.V.; Kutlakhmedov, Yu.O.; Isajenko, V.M.; Krivorot'ko, V.M.

    2006-01-01

    Results of the analysis of 137 Cs radionuclides flows as an example of village Galusia of the Volyn region and in ecosystem of village Kotsubinchiki in Ternopil region polluted by 90 Sr are considered. The analysis is made by the method of box models. The block diagrams of ecosystems were created, and the mathematical models by the method of box models are developed. It has allowed estimating ways of formation doses of an internal irradiation at the expense of products of meal for different groups of population - working people, pensioners and children, and prognosis dynamics of these doses for the next years after Chornobyl NPP accident. It was established, that doses in these villages formed by other ways, depending on radionuclide, pastures structure and levels of their pollution

  10. Development of a predictive model for distribution coefficient (Kd) of 13'7Cs and 60Co in marine sediments using multiple linear regression analysis

    International Nuclear Information System (INIS)

    Kumar, Ajay; Ravi, P.M.; Guneshwar, S.L.; Rout, Sabyasachi; Mishra, Manish K.; Pulhani, Vandana; Tripathi, R.M.

    2018-01-01

    Numerous common methods (batch laboratory, the column laboratory, field-batch method, field modeling and K 0c method) are used frequently for determination of K d values. Recently, multiple regression models are considered as new best estimates for predicting the K d of radionuclides in the environment. It is also well known fact that the K d value is highly influenced by physico-chemical properties of sediment. Due to the significant variability in influencing parameters, the measured K d values can range over several orders of magnitude under different environmental conditions. The aim of this study is to develop a predictive model for K d values of 137 Cs and 60 Co based on the sediment properties using multiple linear regression analysis

  11. The development of models for the transfer of 137Cs and 90Sr in the pasture-cow-milk pathway using fallout data

    International Nuclear Information System (INIS)

    Haywood, S.M.; Simmonds, J.R.; Linsley, G.S.

    1980-11-01

    Records of the measurements of fallout in the UK between the years 1958-77 have been used to develop versions of a general model for transfer in the pasture-cow-milk pathway for the radionuclides 137 Cs and 90 Sr. The revised models take account of the experimentally observed processes of fixation of caesium in soils and the plant base absorption of strontium. They predict, with reasonable accuracy, the variation of activity levels in milk over the period for which records exist. The form of the models permits examination of the relative contributions of the most important transfer mechanisms and their time dependence in the soil-plant system. The study has indicated an upper limit for the resuspension factor in UK rural environments. (author)

  12. Analyses and Comparison of Bulk and Coil Surface Samples from the DWPF Slurry Mix Evaporator

    International Nuclear Information System (INIS)

    Hay, M.; Nash, C.; Stone, M.

    2012-01-01

    Sludge samples from the DWPF Slurry Mix Evaporator (SME) heating coil frame and coil surface were characterized to identify differences that might help identify heat transfer fouling materials. The SME steam coils have seen increased fouling leading to lower boil-up rates. Samples of the sludge were taken from the coil frame somewhat distant from the coil (bulk tank material) and from the coil surface (coil surface sample). The results of the analysis indicate the composition of the two SME samples are very similar with the exception that the coil surface sample shows ∼5-10X higher mercury concentration than the bulk tank sample. Elemental analyses and x-ray diffraction results did not indicate notable differences between the two samples. The ICP-MS and Cs-137 data indicate no significant differences in the radionuclide composition of the two SME samples. Semi-volatile organic analysis revealed numerous organic molecules, these likely result from antifoaming additives. The compositions of the two SME samples also match well with the analyzed composition of the SME batch with the exception of significantly higher silicon, lithium, and boron content in the batch sample indicating the coil samples are deficient in frit relative to the SME batch composition.

  13. Using plot experiments to test the validity of mass balance models employed to estimate soil redistribution rates from 137Cs and 210Pb(ex) measurements.

    Science.gov (United States)

    Porto, Paolo; Walling, Des E

    2012-10-01

    Information on rates of soil loss from agricultural land is a key requirement for assessing both on-site soil degradation and potential off-site sediment problems. Many models and prediction procedures have been developed to estimate rates of soil loss and soil redistribution as a function of the local topography, hydrometeorology, soil type and land management, but empirical data remain essential for validating and calibrating such models and prediction procedures. Direct measurements using erosion plots are, however, costly and the results obtained relate to a small enclosed area, which may not be representative of the wider landscape. In recent years, the use of fallout radionuclides and more particularly caesium-137 ((137)Cs) and excess lead-210 ((210)Pb(ex)) has been shown to provide a very effective means of documenting rates of soil loss and soil and sediment redistribution in the landscape. Several of the assumptions associated with the theoretical conversion models used with such measurements remain essentially unvalidated. This contribution describes the results of a measurement programme involving five experimental plots located in southern Italy, aimed at validating several of the basic assumptions commonly associated with the use of mass balance models for estimating rates of soil redistribution on cultivated land from (137)Cs and (210)Pb(ex) measurements. Overall, the results confirm the general validity of these assumptions and the importance of taking account of the fate of fresh fallout. However, further work is required to validate the conversion models employed in using fallout radionuclide measurements to document soil redistribution in the landscape and this could usefully direct attention to different environments and to the validation of the final estimates of soil redistribution rate as well as the assumptions of the models employed. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Modeling the washoff of 90Sr and 137Cs from an experimental plot established in the vicinity of the Chernobyl reactor

    International Nuclear Information System (INIS)

    Nair, S.K.; Hoffman, F.O.; Thiessen, K.M.; Konoplev, A.V.

    1996-01-01

    After the Chernobyl event, a large area of land was contaminated following the deposition of radionuclides. This area became a continuing source of radionuclides to natural waters and aquatic ecosystems. In 1986, an experimental plot was constructed in a contaminated area near the Chernobyl Nuclear Power Plant to study the washoff of radionuclides by surface runoff. Concentrations of 137 Cs and 90 Sr were measured in the top 10 cm of the soil prior to the experiments. During two separate experiments, intense artificial rainfall was applied to the plot. A washoff scenario was prepared with site-specific information on initial soil contamination, duration and quantities of rainfall and runoff, physicochemical properties of the topsoil, and some climatological data. Modelers were asked to predict (a) the vertical distributions of the initial concentrations of 137 Cs and 90 Sr in various chemical forms in the topsoil, (b) concentrations of these radionuclides in various chemical forms in the runoff water during each experiment, and (c) the total amounts of these radionuclides in various chemical forms in the runoff water during each experiment, and (c) the total amounts of these radionuclides that were washed off during each experiment. A vertical, one-dimensional, multiphase, multispecies transport model was then developed to simulate the movement of contaminants in the topsoil during the 160-d period between the Chernobyl event and the experiments as well as the washouts of contaminants by runoff during the experiments and during the 24-h period thereafter. The model provided very good predictions of the vertical distributions of total contaminant concentrations in the top 10 cm of the soil; however, the concentrations in individual chemical forms were not predicted as accurately. The complete modeling approach and comparisons of model predictions with measurements and with predictions from other modelers are presented. 19 refs., 22 figs., 8 tabs

  15. CS Bond formation by

    Indian Academy of Sciences (India)

    2017-02-02

    Feb 2, 2017 ... a thiol substituent at position-2 of the quinazoline ring. ... coupling reactions represent great contribution to the recent growth of organic synthesis.2 ... Difficulties in C-S ...... Experimental Advances (Amsterdam: Elsevier) 19; (b).

  16. Coil Optimization for HTS Machines

    DEFF Research Database (Denmark)

    Mijatovic, Nenad; Jensen, Bogi Bech; Abrahamsen, Asger Bech

    An optimization approach of HTS coils in HTS synchronous machines (SM) is presented. The optimization is aimed at high power SM suitable for direct driven wind turbines applications. The optimization process was applied to a general radial flux machine with a peak air gap flux density of ~3T...... is suitable for which coil segment is presented. Thus, the performed study gives valuable input for the coil design of HTS machines ensuring optimal usage of HTS tapes....

  17. Large superconducting coil fabrication development

    International Nuclear Information System (INIS)

    Brown, R.L.; Allred, E.L.; Anderson, W.C.; Burn, P.B.; Deaderick, R.I.; Henderson, G.M.; Marguerat, E.F.

    1975-01-01

    Toroidal fields for some fusion devices will be produced by an array of large superconducting coils. Their size, space limitation, and field requirements dictate that they be high performance coils. Once installed, accessibility for maintenance and repairs is severely restricted; therefore, good reliability is an obvious necessity. Sufficient coil fabrication will be undertaken to develop and test methods that are reliable, fast, and economical. Industrial participation will be encouraged from the outset to insure smooth transition from development phases to production phases. Initially, practice equipment for three meter bore circular coils will be developed. Oval shape coil forms will be included in the practice facility later. Equipment that is more automated will be developed with the expectation of winding faster and obtaining good coil quality. Alternate types of coil construction, methods of winding and insulating, will be investigated. Handling and assembly problems will be studied. All technology developed must be feasible for scaling up when much larger coils are needed. Experimental power reactors may need coils having six meter or larger bores

  18. How much detail is needed in modeling a transcranial magnetic stimulation figure-8 coil : Measurements and brain simulations

    NARCIS (Netherlands)

    Petrov, Petar I.; Mandija, Stefano; Sommer, Iris E.C.; Van Den Berg, Cornelis A.T.; Neggers, Sebastiaan F.W.

    2017-01-01

    Background: Despite TMS wide adoption, its spatial and temporal patterns of neuronal effects are not well understood. Although progress has been made in predicting induced currents in the brain using realistic finite element models (FEM), there is little consensus on how a magnetic field of a

  19. Automatic treatment of multiple wound coils in 3D finite element problems including multiply connected regions

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, P.J.; Lai, H.C.; Eastham, J.F.; Al-Akayshee, Q.H. [Univ. of Bath (United Kingdom)

    1996-05-01

    This paper describes an efficient scheme for incorporating multiple wire wound coils into 3D finite element models. The scheme is based on the magnetic scalar representation with an additional basis for each coil. There are no restrictions on the topology of coils with respect to ferromagnetic and conductor regions. Reduced scalar regions and cuts are automatically generated.

  20. Derivation of 137Cs deposition density from measurement of 137Cs inventories in undisturbed soils

    International Nuclear Information System (INIS)

    Hien, P.D.; Hiep, H.T.; Quang, N.H.; Huy, N.Q.; Binh, N.T.; Hai, P.S.; Long, N.Q.; Bac, V.T

    2012-01-01

    The 137 Cs inventories in undisturbed soils were measured for 292 locations across the territory of Vietnam. the logarithmic inventory values were regressed against characteristics of sampling sites, such as geographical coordinates, annual rainfall and physico-chemical parameters of soil. The regression model containing latitude and annual rainfall as determinants could explain 76% of the variations in logarithmic inventory values across the territory. The model part was interpreted as the logarithmic 137 Cs deposition density. At the 95% confidence level, 137 Cs deposition density could be predicted be the model ± 7% relative uncertainty. the latitude mean 137 Cs deposition density increases northward from 237 Bq m -2 to 1097 Bq m -2 , while the corresponding values derived from the UNSCEAR (1969) global pattern are 300 Bq m -2 and 600 Bq m -2 . High 137 Cs inputs were found in high-rainfall areas in northern and central parts of the territory. (author)

  1. The coiled coil motif in polymer drug delivery systems

    Czech Academy of Sciences Publication Activity Database

    Pechar, Michal; Pola, Robert

    2013-01-01

    Roč. 31, č. 1 (2013), s. 90-96 ISSN 0734-9750 R&D Projects: GA ČR GA203/08/0543; GA MŠk 1M0505 Institutional research plan: CEZ:AV0Z40500505 Keywords : coiled coil * hydrophilic polymer * recombinant protein Subject RIV: CD - Macromolecular Chemistry Impact factor: 8.905, year: 2013

  2. FRC translation into a compression coil

    International Nuclear Information System (INIS)

    Chrien, R.E.

    1986-01-01

    The equilibrium and translational kinematics of Field-Reversed Configurations (FRCs) in a cylindrical coil which does not conserve flux are problems that arise in connection with adiabatic compressional heating. In this paper, they consider several features of the problem of FRC translation into a compression coil. First, the magnitude of the guide field is calculated and found to exceed that which would be applied to a flux conserver. Second, energy conservation is applied to FRC translation from a flux conserver into a compression coil. It is found that a significant temperature decrease is required for translation to be energetically possible. The temperature change depends on the external inductance in the compression circuit. An analogous case is that of a compression region composed of a compound magnet; in this case the temperature change depends on the ratio of inner and outer coil radii. Finally, the kinematics of intermediate translation states are calculated using an abrupt transition model. It is found, in this model, that the FRC must overcome a potential hill during translation, which requires a small initial velocity

  3. Differential Search Coils Based Magnetometers: Conditioning, Magnetic Sensitivity, Spatial Resolution

    Directory of Open Access Journals (Sweden)

    Timofeeva Maria

    2012-03-01

    Full Text Available A theoretical and experimental comparison of optimized search coils based magnetometers, operating either in the Flux mode or in the classical Lenz-Faraday mode, is presented. The improvements provided by the Flux mode in terms of bandwidth and measuring range of the sensor are detailed. Theory, SPICE model and measurements are in good agreement. The spatial resolution of the sensor is studied which is an important parameter for applications in non destructive evaluation. A general expression of the magnetic sensitivity of search coils sensors is derived. Solutions are proposed to design magnetometers with reduced weight and volume without degrading the magnetic sensitivity. An original differential search coil based magnetometer, made of coupled coils, operating in flux mode and connected to a differential transimpedance amplifier is proposed. It is shown that this structure is better in terms of volume occupancy than magnetometers using two separated coils without any degradation in magnetic sensitivity. Experimental results are in good agreement with calculations.

  4. Structural design of the superconducting Poloidal Field coils for the Tokamak Physics Experiment

    International Nuclear Information System (INIS)

    O'Connor, T.G.; Zbasnik, J.P.

    1993-01-01

    The Tokamak Physics Experiment concept design uses superconducting coils made from cable-in-conduit conductor to accomplish both magnetic confinement and plasma initiation. The Poloidal Field (PF) magnet system is divided into two subsystems, the central solenoid and the outer ring coils, the latter is focus of this paper. The eddy current heating from the pulsed operation is excessive for a case type construction; therefore, a ''no case'' design has been chosen. This ''no case'' design uses the conductor conduit as the primary structure and the electrical insulation (fiberglass/epoxy wrap) as a structural adhesive. The model integrates electromagnetic analysis and structural analysis into the finite element code ANSYS to solve the problem. PF coil design is assessed by considering a variety of coil current wave forms, corresponding to various operating modes and conditions. The structural analysis shows that the outer ring coils are within the requirements of the fatigue life and fatigue crack growth requirements. The forces produced by the Toroidal Field coils on the PF coils have little effect on the maximum stresses in the PF coils. In addition in an effort to reduce the cost of the coils new elongated PF coils design was proposed which changes the aspect ratio of the outer ring coils to reduce the number of turns in the coils. The compressive stress in the outer ring coils is increased while the tensile stress is decreased

  5. Conceptual design of dump resistor for superconducting CS of SST-1

    International Nuclear Information System (INIS)

    Roy, Swati; Pradhan, Subrata; Panchal, Arun

    2015-01-01

    During the upgradation of SST-1, the resistive central solenoid (CS) coil has been planned to be replaced with Nb 3 Sn based superconducting coil. The superconducting CS will store upto 3.5MJ of magnetic energy per operation cycle with operating current upto 14kA. In case of coil quench, the energy stored in the coils is to be extracted rapidly with a time constant of 1.5s. This will be achieved by inserting a 20m Ohm dump resistor in series with the superconducting CS which is normally shorted by circuit breakers. As a vital part of the superconducting CS quench protection system, a conceptual design of the 20m Ohm dump resistor has been proposed. In this paper, the required design aspects and a dimensional layout of the dump resistor for the new superconducting CS has been presented. Natural air circulation is proposed as cooling method for this dump resistor. The basic structure of the proposed dump resistor comprises of stainless steel grids connected in series in the shape of meander to minimize the stray inductance and increase the surface area for cooling. The entire dump resistor will be an array of such grids connected in series and parallel to meet electrical as well as thermal parameters. The maximum temperature of the proposed dump resistor is upto 350 °C during dump 3.5MJ energy. The proposed design permits indigenous fabrication of the dump resistor using commercially available welding techniques. (author)

  6. Design of Electromagnetic Moving-coil type Voice Coil Motor for Scanning mirror of Barcode reader

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Bu Hyun; Lee, Jeong Woo; Shim, Hyun Ho; Park, Sang Goo [Hanbat National Univ., Daejeon (Korea, Republic of); Lee, Seung Yop [Sogang Univ., Seoul (Korea, Republic of)

    2016-01-15

    A voice coil actuator with moving coil type for scanning mirror system of barcode reader has been developed. The actuator has a simple structure including a magnet, a coil and a pin. The performance of the actuator is analyzed by a linearized theoretical model. And the dynamic performance of the proposed actuator is predicted through motor constant and restoring constant obtained by finite element simulations. The theoretical model was verified by the prototype which has 64 Hz resonance frequency and 60 deg reflecting angle. We also discovered that that 3 V input can make the actuator rotate over 61.8 deg reflecting angle at 50 Hz resonance frequency. The proposed actuator can simplify its driving configuration because of its implementation of open-loop control.

  7. Investigation on biokinetics of 134Cs and 241Am radionuclides in three different organisms and a new evaluation by using discrete time model

    International Nuclear Information System (INIS)

    Guengoer, N.

    1999-05-01

    In this study, 134 Cs and 241 Am biokinetic experiments have been observed originally for Black Sea condition with using the gastropod Patella coerulea and the macro algae Enteremorpha linza and the common mussel Mytilus galloprovlncialis as bio indicator organisms. The experiments that have at least three originality, have been carried out very carefully and biokinetic parameters have been calculated by using classical model. The results are compared with the proportionally similar experiments in the literature globally. In this thesis, a new model application has proposed for the biokinetic evaluation for loss experiments of organisms. That is discrete time model. Loss experiments can be evaluated proportionally in a quick and easy way by using this model. Then, it can be observed that the calculated decreasing factor (r) by discrete time model, shows the loss process quality. Moreover, the loss experiments can be stopped when the decreasing factor goes to 1. So, the loss experiment can be evaluated rapidly and quickly with the adequate reliability by using discrete time model. Furthermore, the loss process in the organisms becomes slower and biologic half-lives becomes longer, when the decreasing factor (r) goes to 1. On the other hand, the biological depuration rate (k) goes to nearly zero. So, the proposed discrete time model that is applied in this thesis originally for biokinetic, can be evident that it has an adequate reliability for the biokinetic evaluation

  8. Transfer of 137Cs to wild vegetables

    International Nuclear Information System (INIS)

    Ito, Nobuhiko; Natsuhori, Masahiro; Mezawa, Akane; Kawakami, Akira

    1998-01-01

    For the evaluation of internal radiation dose, it is needed to estimate the amount of radionuclide incorporated to human body using a simulation model. 137 Cesium (Cs) is easily transferred associating with food intake as well as potassium and so, Cs is an important nuclide for evaluation of internal radiation. 137 Cs concentrations in wild vegetables are higher than those of cultured vegetables and milk. Therefore, the transfer coefficients of 137 Cs from soil to wild vegetables were estimated in this study. Wild vegetables and soils of their farms were collected in the Hakkoda Mountain range of Aomori Prefecture. The levels of 137 Cs in wild vegetables were 0.42-18.35 (Bq/kg), whereas those in cabbage and spinach were 0.08 and 0.01 (Bq/kg), respectively, indicating that the Cs level is dozens to several hundreds times higher in wild vegetables than cultured ones. And the transfer coefficient was estimated as 0.003-0.94 for the former and 0.001-0.8 for the latter. On the other hand, 1 37 Cs levels of the soils on which wild vegetables grew was 28.0 Bq/kg and it was 3.9 Bq/kg for the farm soil. Furthermore, the effects of water content and pH of the soil on the transfer coefficient were studied. (M.N.)

  9. Adsorption of Cs+, Ni2+ and lanthanides onto a kaolinite and Na-montmorillonite up to 1500C: an experimental and modeling study

    International Nuclear Information System (INIS)

    Tertre, E.

    2005-10-01

    The motivation for this study is to assess the temperature effect on the clay minerals sorption properties. Sorption and desorption of Cs + , Ni 2+ et Ln 3+ onto a montmorillonite and a kaolinite were performed by batch experiments between 25 and 150 C, and in different pH and ionic strengths conditions. Sorption enthalpies varying between 0 and 80 kJ/mol were then calculated. For europium, surface spectroscopic analyses confirmed that the mechanism involved is adsorption, including at 150 C. Moreover, this method allowed us to obtain qualitatively the different adsorption equilibrium occurring during the reaction. An acid/base study of the clay surfaces was performed in order to assess the temperature effect on the surface charge of these minerals. Then, a surface complexation model including edge sites and structural sites was proposed to interpret the acid/base data and the europium sorption data. (author)

  10. Numerical characterization of a flexible circular coil for magnetic resonance imaging

    Science.gov (United States)

    Bautista, T.; Hernandez, R.; Solis-Najera, S. E.; Rodriguez, A. O.

    2012-10-01

    Numerical simulations of the magnetic field generated by a flexible surface coil were conducted to study its behavior for applications of animal models at 7 Tesla. This coil design is able to fully cover a volume of interest. The Finite Difference Method in Time Domain (FDTD) was used because of its ability to accurately model complex problems in electromagnetism. This particular coil design is best suited for regions of interests with a spherical shape, since B1 uniformity is not significantly attenuated as in the case of a circular-loop coil. It still remains to investigate the feasibility to actually construct a coil prototype.

  11. The IEA Large Coil Task

    International Nuclear Information System (INIS)

    Beard, D.S.; Klose, W.; Shimamoto, S.; Vecsey, G.

    1988-01-01

    A multinational program of cooperative research, development, demonstrations, and exchanges of information on superconducting magnets for fusion was initiated in 1977 under an IEA agreement. The first major step in the development of TF magnets was called the Large Coil Task. Participants in LCT were the U.S. DOE, EURATOM, JAERI, and the Departement Federal de l'Interieur of Switzerland. The goals of LCT were to obtain experimental data, to demonstrate reliable operation of large superconducting coils, and to prove design principles and fabrication techniques being considered for the toroidal magnets of thermonuclear reactors. These goals were to be accomplished through coordinated but largely independent design, development, and construction of six test coils, followed by collaborative testing in a compact toroidal test array at fields of 8 T and higher. Under the terms of the IEA Agreement, the United States built and operated the test facility at Oak Ridge and provided three test coils. The other participants provided one coil each. Information on design and manufacturing and all test data were shared by all. The LCT team of each participant included a government laboratory and industrial partners or contractors. The last coil was completed in 1985, and the test assembly was completed in October of that year. Over the next 23 months, the six-coil array was cooled down and extensive testing was performed. Results were gratifying, as tests achieved design-point performance and well beyond. (Each coil reached a peak field of 9 T.) Experiments elucidated coil behavior, delineated limits of operability, and demonstrated coil safety. (orig./KP)

  12. Superconducting cyclotron magnet coil short

    International Nuclear Information System (INIS)

    Mallory, M.L.; Blosser, H.G.; Clark, D.J.; Launer, H.; Lawton, D.; Miller, P.; Resmini, F.

    1982-01-01

    In February 1981, a short circuit appeared in the superconducting coil of the K500 cyclotron. The short is resistive in character and therefore has no effect on steady state operation of the magnet. The resistance of the short varies, sometimes being below threshold of detection as a heat load on the cooling system and sometimes being significant. The resistance under certain conditions shows approximately cyclic phenomena with time constants in the range of seconds and other approximately cyclic phenomena which correlate with gross operating parameters of the magnet (shifting current from one coil to another at high field and lowering and raising the liquid helium level). A number of diagnostic studies of the short have been made, using 1) an array of flux sensing loops to sense the magnetic effect of the short, 2) voltage comparisons between upper and lower sections of the coil, 3) comparisons of forces in the nine member coil support system and 4) the effect of the short on the thermal charactersitics of the coil. Insulation failure or a metal chip shorting out turns have been explored in some detail but a convincing determination of the exact cause of the short may never be available, (even the extreme step of unwinding the coil having a significant probability that an imperfection with the observed characteristics would pass unnoticed). Analysis of the characteristics of the short indicated that the most serious consequence would be failure of the coils mechanical support system in the event that the magnet was quickly discharged, as in a dump or quench. To deal with this hazard, the support system has been modified by installing solid supports which prevent the coil from moving by an amount sufficient to damage the support system. We have also reexamined the data and calculations used in the original coil design and have made some additional measurements of the properties of the materials (yield strength, friction coefficient, Young's modulus) used in the

  13. Modeling the washoff of 90Sr and 137Cs from an experimental plot established in the vicinity of the Chernobyl reactor.

    Science.gov (United States)

    Nair, S K; Hoffman, F O; Thiessen, K M; Konoplev, A V

    1996-12-01

    After the Chernobyl event, a large area of land was contaminated following the deposition of radionuclides. This area became a continuing source of radionuclides to natural waters and aquatic ecosystems. In 1986, an experimental plot was constructed in a contaminated area near the Chernobyl Nuclear Power Plant to study the washoff of radionuclides by surface runoff. Concentrations of 137Cs and 90Sr were measured in the top 10 cm of the soil prior to the experiments. During two separate experiments, intense artificial rainfall was applied to the plot. A washoff scenario was then prepared with site-specific information on initial soil contamination, duration and quantities of rainfall and runoff, physicochemical properties of the topsoil, and some climatological data. Modelers were asked to predict (a) the vertical distributions of the initial concentrations of 137Cs and 90Sr in various chemical forms in the topsoil, (b) concentrations of these radionuclides in various chemical forms in the runoff water during each experiment, and (c) the total amounts of these radionuclides that were washed off during each experiment. Stochastically generated local rainfall data were used in a water budget model to generate annual average runoff and infiltration rates. A vertical, one-dimensional, multiphase, multispecies transport model was then developed to simulate the movement of contaminants in the topsoil during the 160-d period between the Chernobyl event and the experiments as well as the washouts of contaminants by runoff during the experiments and during the 24-h period thereafter. The model provided very good predictions of the vertical distributions of total contaminant concentrations in the top 10 cm of the soil; however, the concentrations in individual chemical forms were not predicted as accurately. Initially, the model overpredicted the washout of contaminants for the two experiments and the 24-h period thereafter. Fraction of runoff that flows as interflow and

  14. Environmental sciences: general. 2. Water Adsorption/Absorption by CsOH Particles

    International Nuclear Information System (INIS)

    Riggs, C.A.; Ghosh, T.K.; Tompson, R.V.; Loyalka, S.K.; Viswanath, D.S.

    2001-01-01

    . Following regeneration, samples were cooled to a predetermined temperature by circulating water through a heat exchanger coil wrapped around the glass hang-down tube. Water vapor was introduced incrementally from a reservoir containing degassed-water. Temperature and mass change were monitored on strip chart recorders, with system pressure logged after each increment of the system pressure. The data were recorded once the system reached its equilibrium as indicated by the constant pressure and weight of the system. Water adsorption/absorption data on CsOH exhibited a significant departure from the Langmuir model. The data were Type III isotherms at low pressures, whereas they were step-like isotherms at the higher pressures (see Fig. 2). The isotherms in Fig. 2 indicate that a phase transformation of CsOH took place during the experimentation that was dependent on the relative pressure of water vapor. It appears that CsOH transformed from monohydrate to hexa-hydrate according to Eq. (2): CsOH.H 2 O (s) + 5H 2 O ↔ CsOH.6H 2 O (l) . (2) The isotherms obtained in this research could be used to predict the amount of water vapor absorbed/adsorbed by CsOH particles released during a reactor transient. Large CsOH wetted agglomerates would be available to rapidly react with radioactive iodine released according to Eq. (1). This would limit the amount of radioactive iodine available for off-site release. The water adsorption data could also be used for input of cesium chemical species data into computer codes used in the study of containment aerosols such as CONTAIN, MELCOR, and SCDAP/RELAP (Refs. 4, 5, and 6, respectively). This will help to improve calculation of the effect of various chemical species on the amount of radioactive iodine released off-site. (authors)

  15. Superconducting poloidal coils for STARFIRE commercial reactor

    International Nuclear Information System (INIS)

    Wang, S.T.; Evans, K. Jr.; Turner, L.R.; Huang, Y.C.; Prater, R.; Alcorn, J.

    1979-01-01

    STARFIRE is considered to be the tenth commercial tokamak power plant. A preliminary design study on its superconducting poloidal coil system is presented. Key features of the design studies are: the elimination of the ohmic heating coil; the trade-off studies of the equilibrium field coil locations; and the development of a conceptual design for the superconducting equilibrium field coils. Described are the 100 kA cryostable conductor design, the coil structure, and evaluation of the coil forces

  16. Endothelial cell proliferation in swine experimental aneurysm after coil embolization.

    Directory of Open Access Journals (Sweden)

    Yumiko Mitome-Mishima

    Full Text Available After coil embolization, recanalization in cerebral aneurysms adversely influences long-term prognosis. Proliferation of endothelial cells on the coil surface may reduce the incidence of recanalization and further improve outcomes after coil embolization. We aimed to map the expression of proliferating tissue over the aneurysmal orifice and define the temporal profile of tissue growth in a swine experimental aneurysm model. We compared the outcomes after spontaneous thrombosis with those of coil embolization using histological and morphological techniques. In aneurysms that we not coiled, spontaneous thrombosis was observed, and weak, easily detachable proliferating tissue was evident in the aneurysmal neck. In contrast, in the coil embolization group, histological analysis showed endothelial-like cells lining the aneurysmal opening. Moreover, immunohistochemical and morphological analysis suggested that these cells were immature endothelial cells. Our results indicated the existence of endothelial cell proliferation 1 week after coil embolization and showed immature endothelial cells in septal tissue between the systemic circulation and the aneurysm. These findings suggest that endothelial cells are lead to and proliferate in the former aneurysmal orifice. This is the first examination to evaluate the temporal change of proliferating tissue in a swine experimental aneurysm model.

  17. Electric field depth-focality tradeoff in transcranial magnetic stimulation: simulation comparison of 50 coil designs.

    Science.gov (United States)

    Deng, Zhi-De; Lisanby, Sarah H; Peterchev, Angel V

    2013-01-01

    Various transcranial magnetic stimulation (TMS) coil designs are available or have been proposed. However, key coil characteristics such as electric field focality and attenuation in depth have not been adequately compared. Knowledge of the coil focality and depth characteristics can help TMS researchers and clinicians with coil selection and interpretation of TMS studies. To quantify the electric field focality and depth of penetration of various TMS coils. The electric field distributions induced by 50 TMS coils were simulated in a spherical human head model using the finite element method. For each coil design, we quantified the electric field penetration by the half-value depth, d(1/2), and focality by the tangential spread, S(1/2), defined as the half-value volume (V(1/2)) divided by the half-value depth, S(1/2) = V(1/2)/d(1/2). The 50 TMS coils exhibit a wide range of electric field focality and depth, but all followed a depth-focality tradeoff: coils with larger half-value depth cannot be as focal as more superficial coils. The ranges of achievable d(1/2) are similar between coils producing circular and figure-8 electric field patterns, ranging 1.0-3.5 cm and 0.9-3.4 cm, respectively. However, figure-8 field coils are more focal, having S(1/2) as low as 5 cm(2) compared to 34 cm(2) for circular field coils. For any coil design, the ability to directly stimulate deeper brain structures is obtained at the expense of inducing wider electrical field spread. Novel coil designs should be benchmarked against comparison coils with consistent metrics such as d(1/2) and S(1/2). Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Coil protection calculator for TFTR

    International Nuclear Information System (INIS)

    Marsala, R.J.; Lawson, J.E.; Persing, R.G.; Senko, T.R.; Woolley, R.D.

    1989-01-01

    A new coil protection system (CPS) is being developed to replace the existing TFTR magnetic coil fault detector. The existing fault detector sacrifices TFTR operating capability for simplicity. The new CPS, when installed in October of 1988, will permit operation up to the actual coil stress limits parameters in real-time. The computation will be done in a microprocessor based Coil Protection Calculator (CPC) currently under construction at PPL. THe new CPC will allow TFTR to operate with higher plasma currents and will permit the optimization of pulse repetition rates. The CPC will provide real-time estimates of critical coil and bus temperatures and stresses based on real-time redundant measurements of coil currents, coil cooling water inlet temperature, and plasma current. The critical parameter calculations are compared to prespecified limits. If these limits are reached or exceeded, protection action will be initiated to a hard wired control system (HCS), which will shut down the power supplies. The CPC consists of a redundant VME based microprocessor system which will sample all input data and compute all stress quantities every ten milliseconds. Thermal calculations will be approximated every 10ms with an exact solution occurring every second. The CPC features continuous cross-checking of redundant input signal, automatic detection of internal failure modes, monitoring and recording of calculated results, and a quick, functional verification of performance via an internal test system. (author)

  19. Spectroscopic studies, theoretical models and structural characterization. II. Synthesis and X-ray powder diffraction of the elpasolites Cs2NaSmCl6

    International Nuclear Information System (INIS)

    Poblete, V.; Acevedo, R.

    1998-01-01

    In this research work, we report the synthesis and structural characterization of the stoichiometric elpasolite Cs 2 NaSmCl 6 . The synthesis was performed under a solid state reaction in nitrogen atmosphere from the chemicals CsCl, NaCl and SmCl 3 weighted stoichiometrically. The best possible crystallization temperature was obtained using thermal studies of the type DTA/TGA (the thermal treatment was allowed to proceed for 2.5 hours at 755 Centigrade, showing a temperature gradient of 10 Centigrade/minute). The structural characterization by powder X-ray diffraction (XDR) indicates that this elpasolite belongs to the Fm 3m (O h 5 ) space group and the optimized structural parameters are as follows: a 0 = 10.8342 Armstrong, V 1271.72 Armstrong 3 , Z=4, M=651.88, D x =3.406 y D exp=3.41 ± 0.01. The profile refinement, using the Rietveld method, allowed us to fit the experimental and the calculated intensities of a total of 32 lines. The above result indicates that the condition R exp 2+ + 3Cl -1 and the counter ions filling the octahedral holes, in full agreement with anti fluorite type crystal. According to the above description, these elpasolite adopt the form (M 1/3 □ 2/3 ) 4 X 2 , where M labels the central metal, X stand for the chlorine ions and □ represent the vacancies, which may accommodate a significant amount of defects without collapsing. This experimental study provides the necessary input to test theoretical models against experimental data. (Author)

  20. Study on the optimum design of a high temperature superconducting coil

    International Nuclear Information System (INIS)

    Ishiguri, Shinichi; Yamaguchi, Mitsugi; Fukui, Satoshi; Ogawa, Jun; Sato, Takao

    2005-01-01

    It is in particular of importance for HTS coils to secure a larger central magnetic field, a large stored energy, etc. with shorter length of HTS tapes. The critical current of an HTS tape depends on both the flux density and the flux angle with respect to tapes. In view of this, the performance improvement of HTS coils is taken into account with an analytical model. As a coil shape, the minimum volume coil derived from the Fabry Factor constant curve is taken up, which is often employed at low temperature coils. The electric field distribution within a coil cross-section is calculated to examine effects on a current carrying capability. It is clear that high electric field portions appear at the coil edge region due primarily to inclined magnetic fluxes against HTS tapes. Considering this, a grade winding method of a coil is proposed, where the winding density of conductors is reduced at coil edge portions. With this coil winding structure, the critical current of an HTS coil is improved since the magnetic field is reduced at edge portions. The stored energy per HTS tape length and the central magnetic field of the coil can be remarkably increased by this kind of grade winding method

  1. Composite Coiled Tubing for Extended Reach in Horizontal Oil Wells

    DEFF Research Database (Denmark)

    Costache, Andrei; Berggreen, Christian

    2017-01-01

    Conventional steel coiled tubing cannot reach along the entire length of very long horizontal oil wells. A lighter and more buoyant coiled tube is made possible using composite materials. The high stiffness to weight ratio of fiber reinforced polymers, coupled with a lower coefficient of friction......, has the potential of greatly extending the reach in horizontal oil wells. This study shows how to design composite coiled tubing and gives a comprehensive discussion about the most influential parameters. Several solutions, using glass-fiber and carbon are considered. Finite element models are used...

  2. Numerical dosimetry of transcranial magnetic stimulation coils

    Science.gov (United States)

    Crowther, Lawrence; Hadimani, Ravi; Jiles, David

    2014-03-01

    Transcranial magnetic stimulation (TMS) is a non-invasive neuromodulation technique capable of stimulating neurons by means of electromagnetic induction. TMS can be used to map brain function and shows promise for the diagnosis and treatment of neurological and psychiatric disorders. Calculation of fields induced in the brain are necessary to accurately identify stimulated neural tissue during TMS. This allows the development of novel TMS coil designs capable of stimulating deeper brain regions and increasing the localization of stimulation that can be achieved. We have performed numerical calculations of magnetic and electric field with high-resolution anatomically realistic human head models to find these stimulated brain regions for a variety of proposed TMS coil designs. The realistic head models contain heterogeneous tissue structures and electrical conductivities, yielding superior results to those obtained from the simplified homogeneous head models that are commonly employed. The attenuation of electric field as a function of depth in the brain and the localization of stimulating field have been methodically investigated. In addition to providing a quantitative comparison of different TMS coil designs the variation of induced field between subjects has been investigated. We also show the differences in induced fields between adult, adolescent and child head models to preemptively identify potential safety issues in the application of pediatric TMS.

  3. Multiple-animal MR imaging using a 3T clinical scanner and multi-channel coil for volumetric analysis in a mouse tumor model

    International Nuclear Information System (INIS)

    Mitsuda, Minoru; Yamaguchi, Masayuki; Furuta, Toshihiro; Fujii, Hirofumi; Nabetani, Akira; Hirayama, Akira; Nozaki, Atsushi; Niitsu, Mamoru

    2011-01-01

    Multiple small-animal magnetic resonance (MR) imaging to measure tumor volume may increase the throughput of preclinical cancer research assessing tumor response to novel therapies. We used a clinical scanner and multi-channel coil to evaluate the usefulness of this imaging to assess experimental tumor volume in mice. We performed a phantom study to assess 2-dimensional (2D) geometric distortion using 9-cm spherical and 32-cell (8 x 4 one-cm 2 grids) phantoms using a 3-tesla clinical MR scanner and dedicated multi-channel coil composed of 16 5-cm circular coils. Employing the multi-channel coil, we simultaneously scanned 6 or 8 mice bearing sarcoma 180 tumors. We estimated tumor volume from the sum of the product of tumor area and slice thickness on 2D spin-echo images (repetition time/echo time, 3500/16 ms; in-plane resolution, 0.195 x 0.195 x 1 mm 3 ). After MR acquisition, we excised and weighed tumors, calculated reference tumor volumes from actual tumor weight assuming a density of 1.05 g/cm 3 , and assessed the correlation between the estimated and reference volumes using Pearson's test. Two-dimensional geometric distortion was acceptable below 5% in the 9-cm spherical phantom and in every cell in the 32-cell phantom. We scanned up to 8 mice simultaneously using the multi-channel coil and found 11 tumors larger than 0.1 g in 12 mice. Tumor volumes were 1.04±0.73 estimated by MR imaging and 1.04±0.80 cm 3 by reference volume (average±standard deviation) and highly correlated (correlation coefficient, 0.995; P<0.01, Pearson's test). Use of multiple small-animal MR imaging employing a clinical scanner and multi-channel coil enabled accurate assessment of experimental tumor volume in a large number of mice and may facilitate high throughput monitoring of tumor response to therapy in preclinical research. (author)

  4. Random coil chemical shifts in acidic 8 M urea: Implementation of random coil shift data in NMRView

    International Nuclear Information System (INIS)

    Schwarzinger, Stephan; Kroon, Gerard J.A.; Foss, Ted R.; Wright, Peter E.; Dyson, H. Jane

    2000-01-01

    Studies of proteins unfolded in acid or chemical denaturant can help in unraveling events during the earliest phases of protein folding. In order for meaningful comparisons to be made of residual structure in unfolded states, it is necessary to use random coil chemical shifts that are valid for the experimental system under study. We present a set of random coil chemical shifts obtained for model peptides under experimental conditions used in studies of denatured proteins. This new set, together with previously published data sets, has been incorporated into a software interface for NMRView, allowing selection of the random coil data set that fits the experimental conditions best

  5. Radioanalytical assessment of sedimentation rates in Guajara Bay (Amazon Estuary, N Brazil). A study with unsupported 210Pb and 137Cs modeling

    International Nuclear Information System (INIS)

    Patricia Andrade Neves; Paulo Alves de Lima Ferreira; Marcia Caruso Bicego; Rubens Cesar Lopes Figueira

    2014-01-01

    Guajara Bay is an integral part of the Amazon Estuary system, and functions as the main receiver of urban and industrial wastes from the city of Belem, capital city of PA State (N Brazil). There is a lack of knowledge regarding quantitative measures of sedimentation, such as sedimentation rates, in the literature for this area of the Amazon Estuary. This study aimed the evaluation of recent (time range of 100 years) sedimentation rates in three sediment profiles collected in the coastal system of Guajara Bay with a radioanalytical approach of unsupported 210 Pb and 137 Cs modeling. The mean sedimentation rates for the cores obtained were 0.85 ± 0.12 cm year -1 for Anadim core, 1.02 ± 0.17 cm year -1 for Outeiro core and 0.53 ± 0.04 cm year -1 for Tucunduba core. With the use of three models of sedimentation rate models, it was observed that Anadim and Outeiro core presented constant sedimentation rates for the evaluated time range, but Tucunduba did not. This difference in sedimentation rates was probably due to their different sampling locations that present diverse hydrodynamic regime, with deposition of fine sediments in the upper area of the bay and stronger fluvial currents in the southernmost region. (author)

  6. Stent-assisted coil embolization for cavernous carotid artery aneurysms.

    Science.gov (United States)

    Kono, Kenichi; Shintani, Aki; Okada, Hideo; Tanaka, Yuko; Terada, Tomoaki

    2014-01-01

    Internal carotid artery (ICA) occlusion with or without a bypass surgery is the traditional treatment for cavernous sinus (CS) aneurysms with cranial nerve (CN) dysfunction. Coil embolization without stents frequently requires retreatment because of the large size of CS aneurysms. We report the mid-term results of six unruptured CS aneurysms treated with stent-assisted coil embolization (SACE). The mean age of the patients was 72 years. The mean size of the aneurysms was 19.8 mm (range: 13-26 mm). Before treatment, four patients presented with CN dysfunction and two patients had no symptoms. SACE was performed under local or general anesthesia in three patients each. Mean packing density was 29.1% and tight packing was achieved. There were no neurological complications. CN dysfunction was cured in three patients (75%) and partly resolved in one patient (25%). Transient new CN dysfunction was observed in two patients (33%). Clinical and imaging follow-up ranged from 6 to 26 months (median: 16 months). Recanalization was observed in three patients (50%; neck remnant in two patients and dome filling in one patient), but no retreatment has yet been required. No recurrence of CN dysfunction has occurred yet. In summary, SACE increases packing density and may reduce requirement of retreatment with an acceptable cure rate of CN dysfunction. SACE may be a superior treatment for coiling without stents and be an alternative treatment of ICA occlusion for selected patients, such as older patients and those who require a high-flow bypass surgery or cannot receive general anesthesia.

  7. Coil for LEAR extraction septum

    CERN Multimedia

    CERN PhotoLab

    1982-01-01

    Which way does the current flow ? This intriguing object is the coil for the LEAR extraction septum. There were two septa, first a thin one, then this one, not so thin, somewhat on the borderline between septum and bending magnet.

  8. First coil for the SC

    CERN Multimedia

    CERN PhotoLab

    1955-01-01

    The coils for the SC magnet were stored in the large hangar of the Cointrin Airport (to make sure that they would be available before snow and ice would block the roads and canals from Belgium, where they were built).

  9. Requirements for qualification of manufacture of the ITER Central Solenoid and Correction Coils

    Energy Technology Data Exchange (ETDEWEB)

    Libeyre, Paul, E-mail: paul.libeyre@iter.org [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul lez Durance (France); Li, Hongwei [ITER China, 15B Fuxing Road, Beijing 100862 (China); Reiersen, Wayne [US ITER Project Office, 1055 Commerce Park Dr., Oak Ridge, TN 37831 (United States); Dolgetta, Nello; Jong, Cornelis; Lyraud, Charles; Mitchell, Neil; Laurenti, Adamo [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul lez Durance (France); Sgobba, Stefano [CERN, CH-1211 Genève 23 (Switzerland); Turck, Bernard [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul lez Durance (France); Martovetsky, Nicolai; Everitt, David; Freudenberg, K.; Litherland, Steve; Rosenblad, Peter [US ITER Project Office, 1055 Commerce Park Dr., Oak Ridge, TN 37831 (United States); Smith, John; Spitzer, Jeff [General Atomics, P.O. Box 85608, San Diego, CA 92186-5608 (United States); Wei, Jing; Dong, Xiaoyu; Fang, Chao [ASIPP, Shushan Hu Road 350, Hefei, Anhui 230031 (China); and others

    2015-10-15

    Highlights: • A manufacturing line is installed for the ITER Correction Coils. • A manufacturing line is under installation for the ITER Central Solenoid. • Qualification of the manufacturing procedures has started for both manufacturing lines and acceptance criteria set. • Winding procedure of Correction Coils is qualified. - Abstract: The manufacturing line of the ITER Correction Coils (CC) at ASIPP in Hefei (China) was completed in 2013 and the manufacturing line of the ITER Central Solenoid (CS) modules is under installation at General Atomic premises in Poway (USA). In both cases, before starting production of the first coils, qualification of the manufacturing procedures is achieved by the construction of a set of mock-ups and prototypes to demonstrate that design requirements defined by the ITER Organization are effectively met. For each qualification item, the corresponding mock-ups are presented with the tests to be performed and the related acceptance criteria. The first qualification results are discussed.

  10. Design study of superconducting coils for the fusion DEMO plant at JAERI

    International Nuclear Information System (INIS)

    Isono, T.; Koizumi, N.; Okuno, K.; Kurihara, R.; Nishio, S.; Tobita, K.

    2006-01-01

    A design study of the TF coil for the fusion DEMO plant at JAERI is in progress. A major issue is to estimate the maximum fields generated by the TF coils for three tokamak options and two conductor options. Three tokamak options are proposed varying the aspect ratio and the role of the CS coil. Two kinds of conductors using advanced superconducting materials are candidates for the TF coils: Nb 3 Al and high temperature superconductor (HTS). In order to evaluate achievable magnetic fields, a simple method was adopted to calculate mechanical properties. The estimated maximum fields are 17-20 T by the HTS conductor and 16-17 T by the Nb 3 Al conductor. There is a possibility of a 0.7 T enhancement using grading of Nb 3 Al winding

  11. Structural analysis for the joint of the ITER ELM coil

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shanwen, E-mail: zhangshanwen123@163.com [College of Mechanical Engineering Yangzhou University, Yangzhou 225127 (China); Song, Yuntao; Wang, Zhongwei; Ji, Xiang [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 200031 (China); Zhang, Jianfeng [College of Mechanical Engineering Yangzhou University, Yangzhou 225127 (China)

    2017-01-15

    Highlights: • The FE sub-model method is feasible and rapid for the joint design. • The components meet the static and fatigue criteria. • Nuclear heat is the key factor for the joint design. - Abstract: The joint is an important component of the Edge Localized Modes (ELM) coils in fusion reactor, which is used to connect the ELM coils. Like the ELM coils, the joints work in an environment with high radiation levels, high temperature and high magnetic field. These joints are mainly subject to nuclear heat from the plasma and cyclic electromagnetic (EM) loads induced by the interaction of ELM coil current with magnetic fields. Take the joint of ITER ELM coil for example. In order to assure the structural integrity of joints under these loads, it is necessary to estimate the strength and fatigue of the joints. As a local model, the joint without ELM coil is investigated by the sub-model method. Results show that the finite element sub-model method is feasible and rapid for the joint design. The maximum magnetic flux intensity occurs in the axial direction for the joint local reference, which parallels with the current and corresponds to the toroidal direction of the ITER. The two areas at the top of the Inconel sleeve appear high temperature. For the joint, the conductor, jacket and sleeve can meet the static and fatigue criteria and the joint design is valid and feasible. The thermal load from the nuclear heat is the key factor for the joint design.

  12. Radiation resistant ducted superconductive coil

    International Nuclear Information System (INIS)

    Schleich, A.

    1976-01-01

    The radiation-resistant ducted superconductive coil consists of a helically wound electrical conductor constituted by an electrically conductive core of superconductive material provided with a longitudinally extending cooling duct. The core is covered with a layer of inorganic insulating material and the duct is covered by an electrically conductive metallic gas-tight sheath. The metallic sheaths on adjacent turns of the coil are secured together. 2 Claims, 4 Drawing Figures

  13. The Swiss LCT-coil

    International Nuclear Information System (INIS)

    Vecsey, G.; Benz, H.; Horvath, I.

    1985-01-01

    With delivery of the coil to ORNL on February 4, 1984, the second phase of the Swiss Large Coil Program - design and construction - was terminated. Mainlines of the Swiss design concept are summarized and related to theoretical calculations, experimental results of the supporting program, fabricational experience and first successful test results. An attempt is made to draw preliminary conclusions with regard to the design of future toroidal systems such as NET

  14. Simulation of thermal processes in superconducting pancake coils cooled by GM cryocooler

    International Nuclear Information System (INIS)

    Lebioda, M; Rymaszewski, J; Korzeniewska, E

    2014-01-01

    This article presents the thermal model of a small scale superconducting magnetic energy storage system with the closed cycle helium cryocooler. The authors propose the use of contact-cooled coils with maintaining the possibility of the system reconfiguring. The model assumes the use of the second generation superconducting tapes to make the windings in the form of flat discs (pancakes). The paper presents results for a field model of the single pancake coil and the winding system consisting of several coils.

  15. Equilibrium field coil concepts for INTOR

    International Nuclear Information System (INIS)

    Strickler, D.J.; Peng, Y.K.M.; Brown, T.G.

    1981-08-01

    Methods are presented for reducing ampere-turn requirements in the EF coil system. It is shown that coil currents in an EF coil system external to the toroidal field coils can be substantially reduced by relaxing the triangularity of a D-shaped plasma. Further reductions are realized through a hybrid EF coil system using both internal and external coils. Equilibrium field coils for a poloidally asymmetric, single-null INTOR configuration are presented. It is shown that the shape of field lines in the plasma scrapeoff region and divertor channel improves as triangularity is reduced, but it does so at the possible expense of achievable stable beta values

  16. Validation of the GATE Monte Carlo simulation platform for modelling a CsI(Tl) scintillation camera dedicated to small-animal imaging

    International Nuclear Information System (INIS)

    Lazaro, D; Buvat, I; Loudos, G; Strul, D; Santin, G; Giokaris, N; Donnarieix, D; Maigne, L; Spanoudaki, V; Styliaris, S; Staelens, S; Breton, V

    2004-01-01

    Monte Carlo simulations are increasingly used in scintigraphic imaging to model imaging systems and to develop and assess tomographic reconstruction algorithms and correction methods for improved image quantitation. GATE (GEANT4 application for tomographic emission) is a new Monte Carlo simulation platform based on GEANT4 dedicated to nuclear imaging applications. This paper describes the GATE simulation of a prototype of scintillation camera dedicated to small-animal imaging and consisting of a CsI(Tl) crystal array coupled to a position-sensitive photomultiplier tube. The relevance of GATE to model the camera prototype was assessed by comparing simulated 99m Tc point spread functions, energy spectra, sensitivities, scatter fractions and image of a capillary phantom with the corresponding experimental measurements. Results showed an excellent agreement between simulated and experimental data: experimental spatial resolutions were predicted with an error less than 100 μm. The difference between experimental and simulated system sensitivities for different source-to-collimator distances was within 2%. Simulated and experimental scatter fractions in a [98-82 keV] energy window differed by less than 2% for sources located in water. Simulated and experimental energy spectra agreed very well between 40 and 180 keV. These results demonstrate the ability and flexibility of GATE for simulating original detector designs. The main weakness of GATE concerns the long computation time it requires: this issue is currently under investigation by the GEANT4 and the GATE collaborations

  17. Endovascular rescue method for undesirably stretched coil.

    Science.gov (United States)

    Cho, Jae Hoon

    2014-10-01

    Undesirable detachment or stretching of coils within the parent artery during aneurysm embolization can be related with thrombus formation, which can be caused occlusion of parent artery or embolic event(s). To escape from this situation, several rescue methods have been reported. A case with undesirably stretched coil in which another rescue method was used, is presented. When the stretched coil is still located in the coil delivery microcatheter, the stretched coil can be removed safely using a snare and a handmade monorail microcatheter. After a snare is lodged in the handmade monorail microcatheter, the snare is introduced over the coil delivery micorcatheter and located in the distal part of the stretched coil. After then, the handmade monorail microcatheter captures the stretched coil and the snare as one unit. This technique using a handmade monorail microcatheter and a snare can be a good rescue modality for the undesirably stretched coil, still remained within the coil delivery microcatheter.

  18. Power conditioner for a coil-gun

    International Nuclear Information System (INIS)

    Zabar, Z.; Joshi, P.N.

    1987-01-01

    This paper describes a power conditioning scheme for introducing currents sequentially into a linear array of coils which form the barrel of a coil-gun. The projectile, a conducting cylindrical sleeve, is driven by the force exerted on it by a traveling magnetic wave-packet created by the barrel currents. Since the rate of energy transfer is proportional to the projectile velocity, it was convenient to divide the barrel into three separate sections. These correspond to the low, medium and high velocity parts of the projectile motion. Each section is excited by a different method, chosen to satisfy the need for most efficient usage of energy stored in the power supply capacitors. Experiments are described with a breadboard model that test the feasibility of the medium-velocity power conditioning scheme

  19. Numerical Modeling of 90Sr and 137Cs Transport from a Spill in the B-Cell of the 324 Building, Hanford Site 300 Area

    Energy Technology Data Exchange (ETDEWEB)

    Rockhold, Mark L.; Bacon, Diana H.; Freedman, Vicky L.; Lindberg, Michael J.; Clayton, Ray E.

    2012-03-19

    To characterize the extent of contamination under the 324 Building, a pit was excavated on the north side of the building in 2010 by Washington Closure Hanford LLC (WCH). Horizontal closed-end steel access pipes were installed under the foundation of the building from this pit and were used for measuring temperatures and exposure rates under the B-Cell. The deployed sensors measured elevated temperatures of up to 61 C (142 F) and exposure rates of up to 8,900 R/hr. WCH suspended deactivation of the facility because it recognized that building safety systems and additional characterization data might be needed for remediation of the contaminated material. The characterization work included additional field sampling, laboratory measurements, and numerical flow and transport modeling. Laboratory measurements of sediment physical, hydraulic, and geochemical properties were performed by Pacific Northwest National Laboratory (PNNL) and others. Geochemical modeling and subsurface flow and transport modeling also were performed by PNNL to evaluate the possible extent of contamination in the unsaturated sand and gravel sediments underlying the building. Historical records suggest that the concentrated 137Cs- and 90Sr-bearing liquid wastes that were spilled in B-Cell were likely from a glass-waste repository testing program associated with the Federal Republic of Germany (FRG). Incomplete estimates of the aqueous chemical composition (no anion data provided) of the FRG waste solutions were entered into a geochemical speciation model and were charge balanced with nitrate to estimate waste composition. Additional geochemical modeling was performed to evaluate reactions of the waste stream with the concrete foundation of the building prior to the stream entering the subsurface.

  20. Numerical evaluation of Cs adsorption in PB column by extended Langmuir formula and one-dimensional adsorption model

    International Nuclear Information System (INIS)

    Hiroshi Ogawa; Akiko Kitajima; Hisashi Tanaka; Tohru Kawamoto

    2015-01-01

    Adsorption property of granulated Prussian blue adsorbent on radioactive cesium was evaluated for efficient decontamination in Fukushima area. The adsorbent was found to show an inflective adsorption isotherm, which was expressed by extended Langmuir formula with three adsorption sites. Adsorption speeds of each site were evaluated by time-dependent batch experiment. The simulation using derived parameters and one-dimensional adsorption model successfully reproduced the experimental data of cesium decontamination by small and large columns. (author)

  1. Molecular CsF 5 and CsF 2 +

    KAUST Repository

    Rogachev, Andrey Yu.; Miao, Mao-sheng; Merino, Gabriel; Hoffmann, Roald

    2015-01-01

    D5h star-like CsF5, formally isoelectronic with known XeF5− ion, is computed to be a local minimum on the potential energy surface of CsF5, surrounded by reasonably large activation energies for its exothermic decomposition to CsF+2 F2, or to CsF3 (three isomeric forms)+F2, or for rearrangement to a significantly more stable isomer, a classical Cs+ complex of F5−. Similarly the CsF2+ ion is computed to be metastable in two isomeric forms. In the more symmetrical structures of these molecules there is definite involvement in bonding of the formally core 5p levels of Cs.

  2. Molecular CsF 5 and CsF 2 +

    KAUST Repository

    Rogachev, Andrey Yu.

    2015-06-03

    D5h star-like CsF5, formally isoelectronic with known XeF5− ion, is computed to be a local minimum on the potential energy surface of CsF5, surrounded by reasonably large activation energies for its exothermic decomposition to CsF+2 F2, or to CsF3 (three isomeric forms)+F2, or for rearrangement to a significantly more stable isomer, a classical Cs+ complex of F5−. Similarly the CsF2+ ion is computed to be metastable in two isomeric forms. In the more symmetrical structures of these molecules there is definite involvement in bonding of the formally core 5p levels of Cs.

  3. Coil supporting device in nuclear fusion apparatus

    International Nuclear Information System (INIS)

    Hoshi, Ryo; Imura, Yasuya.

    1974-01-01

    Object: To secure intermediate fittings with a coil fixed thereon by an insulating tape to a fixed body by means of fittings, thereby supporting the coil in a narrow space. Structure: A coil is secured to intermediate fittings by means of an insulating tape, after which the intermediate fittings is mounted on a fixed body through fittings to support the coil in a narrow clearance portion between a plasma sealed vessel and a main coil. (Kamimura, M.)

  4. Thermal and hydraulic analyses of TFTR cooling water system and magnetic field coils

    International Nuclear Information System (INIS)

    Lee, A.Y.

    1975-10-01

    The TFTR toroidal field coils, ohmic heating, hybrid and equilibrium field coils are cooled by water from the machine area cooling water system. The system has the following major equipment and capacities: flow rate of 3600 gpm; ballast tank volume of 5500 gal; pumps of 70.4 m head; chiller refrigeration rating of 3300 tons and connecting pipe of 45.7 cm I.D. The performance of the closed loop system was analyzed and found to be adequate for the thermal loads. The field coils were analyzed with detailed thermal and hydraulic models, including a simulation of the complete water cooling loop. Under the nominal operating mode of one second of toroidal field flat top time and 300 seconds of pulse cycle time, the maximum temperature for the TF coils is 53 0 C; for the OH coils 46 0 C and for the EF coils 39 0 C, which are well below the coil design limit of 120 0 C. The maximum TF coil coolant temperature is 33 0 C which is below the coolant design limit of 100 0 C. The overall pressure loss of the system is below 6.89 x 10 5 Pa (100 psi). With the given chiller refrigeration capacity, the TF coils can be operated to yield up to 4 seconds of flat top time. The TF coils can be operated on a steady state basis at up to 20% of the pulsed duty design current rating of 7.32 kA/coil

  5. Power Loss Analysis and Comparison of Segmented and Unsegmented Energy Coupling Coils for Wireless Energy Transfer.

    Science.gov (United States)

    Tang, Sai Chun; McDannold, Nathan J

    2015-03-01

    This paper investigated the power losses of unsegmented and segmented energy coupling coils for wireless energy transfer. Four 30-cm energy coupling coils with different winding separations, conductor cross-sectional areas, and number of turns were developed. The four coils were tested in both unsegmented and segmented configurations. The winding conduction and intrawinding dielectric losses of the coils were evaluated individually based on a well-established lumped circuit model. We found that the intrawinding dielectric loss can be as much as seven times higher than the winding conduction loss at 6.78 MHz when the unsegmented coil is tightly wound. The dielectric loss of an unsegmented coil can be reduced by increasing the winding separation or reducing the number of turns, but the power transfer capability is reduced because of the reduced magnetomotive force. Coil segmentation using resonant capacitors has recently been proposed to significantly reduce the operating voltage of a coil to a safe level in wireless energy transfer for medical implants. Here, we found that it can naturally eliminate the dielectric loss. The coil segmentation method and the power loss analysis used in this paper could be applied to the transmitting, receiving, and resonant coils in two- and four-coil energy transfer systems.

  6. Bi-2223 HTS winding in toroidal configuration for SMES coil

    International Nuclear Information System (INIS)

    Kondratowicz-Kucewicz, B; Kozak, S; Kozak, J; Wojtasiewicz, G; Majka, M; Janowski, T

    2010-01-01

    Energy can be stored in the magnetic field of a coil. Superconducting Magnetic Energy Storage (SMES) is very promising as a power storage system for load levelling or power stabilizer. However, the strong electromagnetic force caused by high magnetic field and large coil current is a problem in SMES systems. A toroidal configuration would have a much less extensive external magnetic field and electromagnetic forces in winding. The paper describes the design of HTS winding for SMES coil in modular toroid configuration consist of seven Bi-2223 double-pancakes as well as numerical analysis of SMES magnet model using FLUX 3D package. As the results of analysis the paper presents the optimal coil configuration and the parameters such as radius of toroidal magnet, energy stored in magnet and magnetic field distribution.

  7. Study on Dynamic Alignment Technology of COIL Resonator

    International Nuclear Information System (INIS)

    Xiong, M D; Zou, X J; Guo, J H; Jia, S N; Zhang, Z B

    2006-01-01

    The performance of great power chemical oxygen-iodine laser (COIL) beam is decided mostly by resonator mirror maladjustment and environment vibration. To improve the performance of light beam, an auto-alignment device is used in COIL resonator, the device can keep COIL resonator collimating by adjusting the optical components of resonator. So the coupling model of COIL resonator is present. The multivariable self study fuzzy uncoupling arithmetic and six-dimensional micro drive technology are used to design a six-input-three-output uncoupling controller, resulting in the realization of the high precision dynamic alignment. The experiments indicate that the collimating range of this system is 8 mrad, precision is 5 urad and frequency response is 20Hz, which meet the demand of resonator alignment system

  8. A novel design methodology for active shim coil

    International Nuclear Information System (INIS)

    Du, Jun-Jie; Yuan, Ping; Ma, Li-Zhen; Wu, Wei; Yang, Xiao-Liang

    2012-01-01

    A novel design approach for active shimming coils for superconducting magnets is proposed to compensate for the previous ten components of the field deviation. The analytic method is first used to obtain the topologies of coils of various order fields and establish a coil model. Then the particle swarm optimization method is adopted to optimize parameters, and the deviation of the magnetic field is taken as the fitness function for minimization of the bias of a magnetic field. The results from the analytic method are taken as a reference to set the initial value ranges of parameters. The results have shown that, compared with the traditional analytic method, the coils with this method can generate a field of better quality. Also the method involves less internal memory and CPU usage than the pure numerical algorithm. In addition, it has fast searching ability and demonstrates high efficiency; and the global solution can be effectively found, which facilitates directly winding. (paper)

  9. Conceptual design of Dump resistor for Superconducting CS of SST-1

    Science.gov (United States)

    Roy, Swati; Raj, Piyush; Panchal, Arun; Pradhan, Subrata

    2017-04-01

    Under upgradation activities for SST-1, the existing resistive central solenoid (CS) coil will be replaced with Nb3Sn based superconducting coil. Design of Central solenoid had been completed and some of the initiative has already taken for its manufacturing. The superconducting CS will store upto 3 MJ of magnetic energy per operation cycle with operating current upto 14 kA. During quench, energy stored in the coils has to be extracted rapidly with a time constant of 1.5 s by inserting a 20 mΩ dump resistor in series with the superconducting CS which is normally shorted by circuit breakers. As a critical part of the superconducting CS quench protection system, a conceptual design of the 20 mΩ dump resistor has been proposed. The required design aspects and a dimensional layout of the dump resistor for the new superconducting CS has been presented and discussed. The basic structure of the proposed dump resistor comprises of stainless steel grids connected in series in the form of meander to minimize the stray inductance and increase the surface area for cooling. Such an array of grids connected in series and parallel will cater to the electrical as well as thermal parameters. It will be cooled by natural convection. During operation, the estimated maximum temperature of the proposed dump resistor will raise upto 600 K.

  10. Rice Cellulose SynthaseA8 Plant-Conserved Region Is a Coiled-Coil at the Catalytic Core Entrance

    Energy Technology Data Exchange (ETDEWEB)

    Rushton, Phillip S.; Olek, Anna T.; Makowski, Lee; Badger, John; Steussy, C. Nicklaus; Carpita, Nicholas C.; Stauffacher, Cynthia V. (NEU); (Purdue)

    2016-11-22

    The crystallographic structure of a rice (Oryza sativa) cellulose synthase, OsCesA8, plant-conserved region (P-CR), one of two unique domains in the catalytic domain of plant CesAs, was solved to 2.4 Å resolution. Two antiparallel α-helices form a coiled-coil domain linked by a large extended connector loop containing a conserved trio of aromatic residues. The P-CR structure was fit into a molecular envelope for the P-CR domain derived from small-angle X-ray scattering data. The P-CR structure and molecular envelope, combined with a homology-based chain trace of the CesA8 catalytic core, were modeled into a previously determined CesA8 small-angle X-ray scattering molecular envelope to produce a detailed topological model of the CesA8 catalytic domain. The predicted position for the P-CR domain from the molecular docking models places the P-CR connector loop into a hydrophobic pocket of the catalytic core, with the coiled-coil aligned near the entrance of the substrate UDP-glucose into the active site. In this configuration, the P-CR coiled-coil alone is unlikely to regulate substrate access to the active site, but it could interact with other domains of CesA, accessory proteins, or other CesA catalytic domains to control substrate delivery.

  11. Hybridization of Single Nanocrystals of Cs4PbBr6 and CsPbBr3.

    Science.gov (United States)

    Weerd, Chris de; Lin, Junhao; Gomez, Leyre; Fujiwara, Yasufumi; Suenaga, Kazutomo; Gregorkiewicz, Tom

    2017-09-07

    Nanocrystals of all-inorganic cesium lead halide perovskites (CsPbX 3 , X = Cl, Br, I) feature high absorption and efficient narrow-band emission which renders them promising for future generation of photovoltaic and optoelectronic devices. Colloidal ensembles of these nanocrystals can be conveniently prepared by chemical synthesis. However, in the case of CsPbBr 3 , its synthesis can also yield nanocrystals of Cs 4 PbBr 6 and the properties of the two are easily confused. Here, we investigate in detail the optical characteristics of simultaneously synthesized green-emitting CsPbBr 3 and insulating Cs 4 PbBr 6 nanocrystals. We demonstrate that, in this case, the two materials inevitably hybridize, forming nanoparticles with a spherical shape. The actual amount of these Cs 4 PbBr 6 nanocrystals and nanohybrids increases for synthesis at lower temperatures, i.e., the condition typically used for the development of perovskite CsPbBr 3 nanocrystals with smaller sizes. We use state-of-the-art electron energy loss spectroscopy to characterize nanoparticles at the single object level. This method allows distinguishing between optical characteristics of a pure Cs 4 PbBr 6 and CsPbBr 3 nanocrystal and their nanohybrid. In this way, we resolve some of the recent misconceptions concerning possible visible absorption and emission of Cs 4 PbBr 6 . Our method provides detailed structural characterization, and combined with modeling, we conclusively identify the nanospheres as CsPbBr 3 /Cs 4 PbBr 6 hybrids. We show that the two phases are independent of each other's presence and merge symbiotically. Herein, the optical characteristics of the parent materials are preserved, allowing for an increased absorption in the UV due to Cs 4 PbBr 6 , accompanied by the distinctive efficient green emission resulting from CsPbBr 3 .

  12. 137Cs in man organism

    International Nuclear Information System (INIS)

    Marej, A.N.; Barkhudarov, R.M.

    1980-01-01

    Considered are the levels of 137 Cs content in the organism of adult urban population of the USSR and the main regularities of their alterations during 1962-1974. The non-uniform distribution of levels of 137 Cs buildup in adult population is shown to be connected with soil and geographic conditions. Food stuffs of local production have a noticeable effect on the levels of 137 Cs buildup in the organism of urban population. Calculation methods are used to study 137 Cs administration in a human organism. No significant difference is found between the indexes of 137 Cs content in the organism of rural and urban population. Presented are the levels of 137 Cs content in the organisms of inhabitants of such regions as Far North and Byelorussian-Ukrainian woodlands. Given are the reasons for the increased content of 137 Cs in the organism of rural population of these zones

  13. Thermal analysis of track based coils

    Energy Technology Data Exchange (ETDEWEB)

    Davey, K [American MAGLEV, Inc., Edgewater, FL (United States); Zowarka, R [CEM, Austin, TX (United States)

    1996-12-31

    This document examines the temperature rise of coils embedded in a concrete matrix. The ultimate goal is to predict the steady state temperature of the coils subject to a repeated passage of vehicles at a regular interval. The primary concern is in maintaining a maximum temperature which is less than that which would compromise the integrity of the insulation used on the wires. Three techniques are used to examine the problem. First, an analytical approach is used to determine not only the immediate temperature rise of the wire material itself, but also a consevative estimate of the steady state temperature expected. Second, the equations are examined for a one dimensional transient profile of the temperature with time. Finally, a two dimensional steady state boundary element solution is employed to estimate the steady state temperature profile both within the coils and within the rail. In this two dimensional boundary element assessment, an iterative approach is employed to accurately model the heat transfer coefficient h which ultimately defines the steady state temperature. (orig.)

  14. Modelling of the transfer of CS-137 from air to crops, milk, beef and human body following the Chernobyl accident, in a location in Central Bohemia. Test of the model PRYMA T1

    International Nuclear Information System (INIS)

    Carrasco, E.; Garcia-Olivares, A.; Suanez, A.; Robles, B. Simon, I.; Cancio, D.

    1994-01-01

    This work was made in the frame of the research programme on validation of models for the transfer of radionuclides in the terrestrial, urban and aquatic environments. The acronym of this programme is VAMP (Validation of Model Predictions) and is coordinated by the International Atomic Energy Agency (IAEA) and the Commission of the European Communities (CEC). The scenario was named CB and was presented by the Multiple Pathway Working group. The scenario description was at the beginning a blind test, that is without knowing the location or the measured concentrations and doses. The input information included data of contamination in Cs-137 from the Chernobyl accident in Central Europe, in air and soils and more description of the scenario (data about crops, cattele, demography, human diet, etc.). The aim of the exercise was the contrast between model results and between observed data and model predictions. In this work the results obtained by the CIEMAT-IMA group of modelers are shown and discussed

  15. Development of Multiorgan Finite Element-Based Prostate Deformation Model Enabling Registration of Endorectal Coil Magnetic Resonance Imaging for Radiotherapy Planning

    International Nuclear Information System (INIS)

    Hensel, Jennifer M.; Menard, Cynthia; Chung, Peter W.M.; Milosevic, Michael F.; Kirilova, Anna; Moseley, Joanne L.; Haider, Masoom A.; Brock, Kristy K.

    2007-01-01

    Purpose: Endorectal coil (ERC) magnetic resonance imaging (MRI) provides superior visualization of the prostate compared with computed tomography at the expense of deformation. This study aimed to develop a multiorgan finite element deformable method, Morfeus, to accurately co-register these images for radiotherapy planning. Methods: Patients with prostate cancer underwent fiducial marker implantation and computed tomography simulation for radiotherapy planning. A series of axial MRI scans were acquired with and without an ERC. The prostate, bladder, rectum, and pubic bones were manually segmented and assigned linear elastic material properties. Morfeus mapped the surface of the bladder and rectum between two imaged states, calculating the deformation of the prostate through biomechanical properties. The accuracy of deformation was measured as fiducial marker error and residual surface deformation between the inferred and actual prostate. The deformation map was inverted to deform from 100 cm 3 to no coil. Results: The data from 19 patients were analyzed. Significant prostate deformation occurred with the ERC (mean intrapatient range, 0.88 ± 0.25 cm). The mean vector error in fiducial marker position (n = 57) was 0.22 ± 0.09 cm, and the mean vector residual surface deformation (n = 19) was 0.15 ± 0.06 cm for deformation from no coil to 100-cm 3 ERC, with an image vector resolution of 0.22 cm. Accurately deformed MRI scans improved soft-tissue resolution of the anatomy for radiotherapy planning. Conclusions: This method of multiorgan deformable registration enabled accurate co-registration of ERC-MRI scans with computed tomography treatment planning images. Superior structural detail was visible on ERC-MRI, which has potential for improving target delineation

  16. Theoretical study of the Cs isotope exchange reaction of CsI + Cs' → Cs + ICs' (Contract research)

    International Nuclear Information System (INIS)

    Kobayashi, Takanori; Hashimoto, Masashi; Yokoyama, Keiichi

    2015-12-01

    To discuss the exchange reaction of Cs isotope by CsI + Cs' → Cs + ICs', the structure and chemical properties of Cs 2 I intermediate and potential energy surface of the entrance reaction are calculated using M06/def2-TZVPPD density functional calculation. The calculation shows that the reaction to the intermediate has no barrier and the two Cs-I bonds of Cs 2 I are chemically equivalent. These results suggest that the rate of the Cs exchange reaction of CsI + Cs' → Cs + ICs' is as high as the collision rate. (author)

  17. Frameworks in CS1

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak; Caspersen, Michael Edelgaard

    2002-01-01

    In this paper we argue that introducing object-oriented frameworks as subject already in the CS1 curriculum is important if we are to train the programmers of tomorrow to become just as much software reusers as software producers. We present a simple, graphical, framework that we have successfull...... point for introducing graphical user interface frameworks such as Java Swing and AWT as the students are not overwhelmed by all the details of such frameworks right away but given a conceptual road-map and practical experience that allow them to cope with the complexity....

  18. CS Seminar Videos

    OpenAIRE

    Ong, Derek; Tona, Glen; Gibb, Kyle; Parbadia, Sivani

    2013-01-01

    Main site for our project can be found at this URL: http://vtechworks.lib.vt.edu/handle/10919/19036. From here you can find videos of all the CS seminars and distinguished lectures given this semester. Each video has its own abstract and description. The files attached in this section are a final report in both raw Word Document and archival PDF formats and a presentation in both raw Powerpoint and archival PDF formats. Computer Science seminars are a very educational and interesting as...

  19. Frameworks in CS1

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak; Caspersen, Michael Edelgaard

    2002-01-01

    point for introducing graphical user interface frameworks such as Java Swing and AWT as the students are not overwhelmed by all the details of such frameworks right away but given a conceptual road-map and practical experience that allow them to cope with the complexity.......In this paper we argue that introducing object-oriented frameworks as subject already in the CS1 curriculum is important if we are to train the programmers of tomorrow to become just as much software reusers as software producers. We present a simple, graphical, framework that we have successfully...

  20. Redesigning existing transcranial magnetic stimulation coils to reduce energy: application to low field magnetic stimulation

    Science.gov (United States)

    Wang, Boshuo; Shen, Michael R.; Deng, Zhi-De; Smith, J. Evan; Tharayil, Joseph J.; Gurrey, Clement J.; Gomez, Luis J.; Peterchev, Angel V.

    2018-06-01

    Objective. To present a systematic framework and exemplar for the development of a compact and energy-efficient coil that replicates the electric field (E-field) distribution induced by an existing transcranial magnetic stimulation coil. Approach. The E-field generated by a conventional low field magnetic stimulation (LFMS) coil was measured for a spherical head model and simulated in both spherical and realistic head models. Then, using a spherical head model and spatial harmonic decomposition, a spherical-shaped cap coil was synthesized such that its windings conformed to a spherical surface and replicated the E-field on the cortical surface while requiring less energy. A prototype coil was built and electrically characterized. The effect of constraining the windings to the upper half of the head was also explored via an alternative coil design. Main results. The LFMS E-field distribution resembled that of a large double-cone coil, with a peak field strength around 350 mV m‑1 in the cortex. The E-field distributions of the cap coil designs were validated against the original coil, with mean errors of 1%–3%. The cap coil required as little as 2% of the original coil energy and was significantly smaller in size. Significance. The redesigned LFMS coil is substantially smaller and more energy-efficient than the original, improving cost, power consumption, and portability. These improvements could facilitate deployment of LFMS in the clinic and potentially at home. This coil redesign approach can also be applied to other magnetic stimulation paradigms. Finally, the anatomically-accurate E-field simulation of LFMS can be used to interpret clinical LFMS data.

  1. Transient voltage oscillations in coils

    International Nuclear Information System (INIS)

    Chowdhuri, P.

    1985-01-01

    Magnet coils may be excited into internal voltage oscillations by transient voltages. Such oscillations may electrically stress the magnet's dielectric components to many times its normal stress. This may precipitate a dielectric failure, and the attendant prolonged loss of service and costly repair work. Therefore, it is important to know the natural frequencies of oscillations of a magnet during the design stage, and to determine whether the expected switching transient voltages can excite the magnet into high-voltage internal oscillations. The series capacitance of a winding significantly affects its natural frequencies. However, the series capacitance is difficult to calculate, because it may comprise complex capacitance network, consisting of intra- and inter-coil turn-to-turn capacitances of the coil sections. A method of calculating the series capacitance of a winding is proposed. This method is rigorous but simple to execute. The time-varying transient voltages along the winding are also calculated

  2. Diffusion tensor imaging using multiple coils for mouse brain connectomics.

    Science.gov (United States)

    Nouls, John C; Badea, Alexandra; Anderson, Robert B J; Cofer, Gary P; Allan Johnson, G

    2018-04-19

    The correlation between brain connectivity and psychiatric or neurological diseases has intensified efforts to develop brain connectivity mapping techniques on mouse models of human disease. The neural architecture of mouse brain specimens can be shown non-destructively and three-dimensionally by diffusion tensor imaging, which enables tractography, the establishment of a connectivity matrix and connectomics. However, experiments on cohorts of animals can be prohibitively long. To improve throughput in a 7-T preclinical scanner, we present a novel two-coil system in which each coil is shielded, placed off-isocenter along the axis of the magnet and connected to a receiver circuit of the scanner. Preservation of the quality factor of each coil is essential to signal-to-noise ratio (SNR) performance and throughput, because mouse brain specimen imaging at 7 T takes place in the coil-dominated noise regime. In that regime, we show a shielding configuration causing no SNR degradation in the two-coil system. To acquire data from several coils simultaneously, the coils are placed in the magnet bore, around the isocenter, in which gradient field distortions can bias diffusion tensor imaging metrics, affect tractography and contaminate measurements of the connectivity matrix. We quantified the experimental alterations in fractional anisotropy and eigenvector direction occurring in each coil. We showed that, when the coils were placed 12 mm away from the isocenter, measurements of the brain connectivity matrix appeared to be minimally altered by gradient field distortions. Simultaneous measurements on two mouse brain specimens demonstrated a full doubling of the diffusion tensor imaging throughput in practice. Each coil produced images devoid of shading or artifact. To further improve the throughput of mouse brain connectomics, we suggested a future expansion of the system to four coils. To better understand acceptable trade-offs between imaging throughput and connectivity

  3. Evaluation of a model framework to estimate soil and soil organic carbon redistribution by water and tillage using 137Cs in two U.S. Midwest agricultural fields

    Science.gov (United States)

    Young, Claudia J.; Liu, Shuguang; Schumacher, Joseph A.; Schumacher, Thomas E.; Kaspar, Thomas C.; McCarty, Gregory W.; Napton, Darrell; Jaynes, Dan B.

    2014-01-01

    Cultivated lands in the U.S. Midwest have been affected by soil erosion, causing soil organic carbon (SOC) redistribution in the landscape and other environmental and agricultural problems. The importance of SOC redistribution on soil productivity and crop yield, however, is still uncertain. In this study, we used a model framework, which includes the Unit Stream Power-based Erosion Deposition (USPED) and the Tillage Erosion Prediction (TEP) models, to understand the soil and SOC redistribution caused by water and tillage erosion in two agricultural fields in the U.S. Midwest. This model framework was evaluated for different digital elevation model (DEM) spatial resolutions (10-m, 24-m, 30-m, and 56-m) and topographic exponents (m = 1.0–1.6 and n = 1.0–1.3) using soil redistribution rates from 137Cs measurements. The results showed that the aggregated 24-m DEM, m = 1.4 and n = 1.0 for rill erosion, and m = 1.0 and n = 1.0 for sheet erosion, provided the best fit with the observation data at both sites. Moreover, estimated average SOC redistributions were 1.3 ± 9.8 g C m− 2 yr− 1 in field site 1 and 3.6 ± 14.3 g C m− 2 yr− 1 in field site 2. Spatial distribution patterns showed SOC loss (negative values) in the eroded areas and SOC gain (positive value) in the deposition areas. This study demonstrated the importance of the spatial resolution and the topographic exponents to estimate and map soil redistribution and the SOC dynamics throughout the landscape, helping to identify places where erosion and deposition from water and tillage are occurring at high rates. Additional research is needed to improve the application of the model framework for use in local and regional studies where rainfall erosivity and cover management factors vary. Therefore, using this model framework can help to improve the information about the spatial distribution of soil erosion across agricultural landscapes and to gain a better understanding of SOC

  4. Large coil program support structure conceptual design

    International Nuclear Information System (INIS)

    Litherland, P.S.

    1977-01-01

    The purpose of the Large Coil Program (LCP) is to perform tests on both pool boiling and force cooled superconducting toroidal field coils. The tests will attempt to approximate conditions anticipated in an ignition tokamak. The test requirements resulted in a coil support design which accommodates up to six (6) test coils and is mounted to a structure capable of resisting coil interactions. The steps leading to the present LCP coil support structure design, details on selected structural components, and the basic assembly sequence are discussed

  5. Cooling device of superconducting coils

    International Nuclear Information System (INIS)

    Duthil, R.; Lottin, J.C.

    1985-01-01

    This device is rotating around an horizontal axis. The superconducting coils are contained in a cryogenic enclosure feeded in liquid helium forced circulation. They are related to an electric generator by electric mains each of them comprising a gas exchanger, and an exchanger-evaporator set between the cryogenic device and those exchangers. The exchanger-evaporator is aimed at dissipating the heat arriving by conductors connected to the superconducting coils. According to the invention, the invention includes an annular canalization with horizontal axis in which the connection conductors bathe in liquid helium [fr

  6. Determination of Cs-134 and Cs-137 rain water samples

    International Nuclear Information System (INIS)

    Lima, M.F.; Mazzilli, B.

    1988-01-01

    In order to setting an environmental monitoring program at IPEN, was developed a fast and simple methodology for concentration of Cs-134 and Cs-137 in rain water. This procedure consists in the precipitation of cesium and others cathions of its family (NH 4 + , K + and Rb + ) by ammonium molybdophosphate. The measures of the desintegration rates of Cs-134 and Cs-137 was done by gamma spectrometry in a Ge(Li) detector. After setting up the ideal experimental conditions, the procedure was used to analyze four samples of rain water. (author) [pt

  7. Phonon dispersion curves for CsCN

    International Nuclear Information System (INIS)

    Gaur, N.K.; Singh, Preeti; Rini, E.G.; Galgale, Jyostna; Singh, R.K.

    2004-01-01

    The motivation for the present work was gained from the recent publication on phonon dispersion curves (PDCs) of CsCN from the neutron scattering technique. We have applied the extended three-body force shell model (ETSM) by incorporating the effect of coupling between the translation modes and the orientation of cyanide molecules for the description of phonon dispersion curves of CsCN between the temperatures 195 and 295 K. Our results on PDCs in symmetric direction are in good agreement with the experimental data measured with inelastic neutron scattering technique. (author)

  8. Validation of a CATHENA fuel channel model for the post blowdown analysis of the high temperature thermal-chemical experiment CS28-1, I - Steady state

    International Nuclear Information System (INIS)

    Rhee, Bo Wook; Kim, Hyoung Tae; Park, Joo Hwan

    2008-01-01

    To form a licensing basis for the new methodology of the fuel channel safety analysis code system for CANDU-6, a CATHENA model for the post-blowdown fuel channel analysis for a Large Break LOCA has been developed, and tested for the steady state of a high temperature thermal-chemical experiment CS28-1. As the major concerns of the post-blowdown fuel channel analysis of the current CANDU-6 design are how much of the decay heat can be discharged to the moderator via a radiation and a convective heat transfer at the expected accident conditions, and how much zirconium sheath would be oxidized to generate H 2 at how high a fuel temperature, this study has focused on understanding these phenomena, their interrelations, and a way to maintain a good accuracy in the prediction of the fuel and the pressure tube temperatures without losing the important physics of the involved phenomena throughout the post-blowdown phase of a LBLOCA. For a better prediction, those factors that may significantly contribute to the prediction accuracy of the steady state of the test bundles were sought. The result shows that once the pressure tube temperature is predicted correctly by the CATHENA heat transfer model between the pressure tube and the calandria tube through a gap thermal resistance adjustment, all the remaining temperatures of the inner ring, middle ring and outer ring FES temperatures can be predicted quite satisfactorily, say to within an accuracy range of 20-25 deg. C, which is comparable to the reported accuracy of the temperature measurement, ±2%. Also the analysis shows the choice of the emissivity of the solid structures (typically, 0.80, 0.34, 0.34 for FES, PT, CT), and the thermal resistance across the CO 2 annulus are factors that significantly affect the steady state prediction accuracy. A question on the legitimacy of using 'transparent' assumption for the CO 2 gas annulus for the radiation heat transfer between the pressure tube and the calandria tube in CATHENA

  9. Computation of the Mutual Inductance between Air-Cored Coils of Wireless Power Transformer

    International Nuclear Information System (INIS)

    Anele, A O; Hamam, Y; Djouani, K; Chassagne, L; Alayli, Y; Linares, J

    2015-01-01

    Wireless power transfer system is a modern technology which allows the transfer of electric power between the air-cored coils of its transformer via high frequency magnetic fields. However, due to its coil separation distance and misalignment, maximum power transfer is not guaranteed. Based on a more efficient and general model available in the literature, rederived mathematical models for evaluating the mutual inductance between circular coils with and without lateral and angular misalignment are presented. Rather than presenting results numerically, the computed results are graphically implemented using MATLAB codes. The results are compared with the published ones and clarification regarding the errors made are presented. In conclusion, this study shows that power transfer efficiency of the system can be improved if a higher frequency alternating current is supplied to the primary coil, the reactive parts of the coils are compensated with capacitors and ferrite cores are added to the coils. (paper)

  10. Large Coil Program magnetic system design study

    International Nuclear Information System (INIS)

    Moses, S.D.; Johnson, N.E.

    1977-01-01

    The primary objective of the Large Coil Program (LCP) is to demonstrate the reliable operation of large superconducting coils to provide a basis for the design principles, materials, and fabrication techniques proposed for the toroidal magnets for the THE NEXT STEP (TNS) and other future tokamak devices. This paper documents a design study of the Large Coil Test Facility (LCTF) in which the structural response of the Toroidal Field (TF) Coils and the supporting structure was evaluated under simulated reactor conditions. The LCP test facility structural system consists of six TF Coils, twelve coil-to-coil torsional restraining beams (torque rings), a central bucking post with base, and a Pulse Coil system. The NASTRAN Finite Element Structural Analysis computer Code was utilized to determine the distribution of deflections, forces, and stresses for each of the TF Coils, torque rings, and the central bucking post. Eleven load conditions were selected to represent probable test operations. Pulse Coils suspended in the bore of the test coil were energized to simulate the pulsed field environment characteristic of the TNS reactor system. The TORMAC Computer Code was utilized to develop the magnetic forces in the TF Coils for each of the eleven loading conditions examined, with or without the Pulse Coils energized. The TORMAC computer program output forces were used directly as input load conditions for the NASTRAN analyses. Results are presented which demonstrate the reliability of the LCTF under simulated reactor operating conditions

  11. Complex study of transport AC loss in various 2G HTS racetrack coils

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yiran, E-mail: yc315@cam.ac.uk [University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Zhang, Min; Chudy, Michal; Matsuda, Koichi; Coombs, Tim [University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA (United Kingdom)

    2013-04-15

    Highlights: ► Comparing transport AC losses of two types of 2G HTS racetrack coils. ► The magnetic substrate in the MAG RABITS coil is the main difference. ► Experimental data agree well with simulation results. ► The transport AC loss in the MAG RABITS coil is 36% higher than that in the IBAD coil. ► It is better to keep all the substrate non-magnetic. -- Abstract: HTS racetrack coils are becoming important elements of an emerging number of superconducting devices such as generators or motors. In these devices the issue of AC loss is crucial, as performance and cooling power are derived from this quantity. This paper presents a comparative study of transport AC loss in two different types of 2G HTS racetrack coils. In this study, both experimental measurements and computer simulation approaches were employed. All the experiments were performed using classical AC electrical method. The finite-element computer model was used to estimate electromagnetic properties and calculate transport AC loss. The main difference between the characterized coils is covered inside tape architectures. While one coil uses tape based on RABITS magnetic substrate, the second coil uses a non-magnetic tape. Ferromagnetic loss caused by a magnetic substrate is an important issue involved in the total AC loss. As a result, the coil with the magnetic substrate surprised with high AC loss and rather low performance.

  12. BPX toroidal field coil design

    International Nuclear Information System (INIS)

    Heitzenvoeder, D.J.

    1992-01-01

    This paper reports on the toroidal field (TF) coil system of the Burning Plasma Experiment (BPX) which consists of (18) beryllium copper magnets arrayed in a wedged configuration with a major radius of 2.6 meters and a field strength capability on axis of 9.0 Tesla. The toroidal array is constructed from six (3)-coil modules to facilitate remote recovery in the event of a magnet failure after nuclear activation precludes hands-on servicing. The magnets are of a modified Bitter plate design with partial cases of type 316-LN stainless steel welded with Inconel 182 weld wire. The coil turn plates are fabricated from CDA C17510 beryllium copper with optimized mechanical, thermal, and electrical characteristics. joints within the turns and between turns are made by welding with C17200 filler wire. Cryogenic cooling is employed to reduce power dissipation and to enhance performance. The magnets are cooled between experimental pulses by pressurized liquid nitrogen flowing through channels in the edges of the coil turns. This arrangement makes possible one full-power pulse per hour. Electrical insulation consists of polyimide-glass sheets bonded in place with vacuum-pressure impregnated epoxy/glass

  13. Demonstration poloidal coil test facility

    International Nuclear Information System (INIS)

    Sato, Masahiko; Kawano, Katumi; Tada, Eisuke

    1989-01-01

    A new compact cryogenic cold compressor was developed by Japan Atomic Energy Research Institute (JAERI) in collaboration with Isikawajima-Harima Heavy Industries Co., Ltd. (IHI) in order to produce the supercritical helium below 4.2 K for Demonstration Poloidal Coils (DPC) which are forced-flow cooled type superconducting pulse coils. This compressor is one of key components for DPC test facility. The cold compressor reduces pressure in liquid helium bath, which contains liquid helium of around 3,000 l, down to 0.5 atm efficiently. Consequently, supercritical helium down to 3.5 K is produced and supplied to the DPC coils. A centrifugal compressor with dynamic gas bearing is selected as a compressor mechanism to realize high adiabatic efficiency and large flow rate. In this performance tests, the compressor was operated for 220 h at saturated condition from 0.5 to 1.0 atm without any failure. High adiabatic efficiency (more than 60 %) is achieved with wide flow range (25-65 g/s) and the design value is fully satisfied. The compressor can rotate up to 80,000 rpm at maximum then the coil supply temperature of supercritical helium is 3.5 K. (author)

  14. Open-Coil Retraction Spring

    Directory of Open Access Journals (Sweden)

    Pavankumar Janardan Vibhute

    2011-01-01

    Full Text Available Sliding mechanic has become a popular method for space closure with developments in preadjusted edgewise appliance. Furthermore, various space closing auxiliaries have been developed and evaluated extensively for their clinical efficiency. Their effectiveness enhanced with optimum force magnitude and low-load deflection rate (LDR/force decay. With the advent of NiTi springs in orthodontics, LDRs have been markedly reduced. For use of NiTi, clinician has to depend upon prefabricated closed coil springs. “Open Coil Retraction Spring (OCRS” is developed utilizing NiTi open-coil spring for orthodontic space closure. This paper describes fabrication and clinical application of OCRS which have number of advantages. It sustains low LDR with optimum force magnitude. Its design is adjustable for desired length and force level. It is fail-safe for both activation and deactivation (i.e., it cannot be over activated, and decompression limit of open coil is also controlled by the operator, resp.. A possibility to offset the OCRS away from mucosa helps to reduce its soft-tissue impingement.

  15. Distribution and behavior of {sup 137}Cs in undisturbed soil

    Energy Technology Data Exchange (ETDEWEB)

    Satta, Naoya [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.

    1996-04-01

    The depth distribution of {sup 137}Cs in soils which has not been artificially disturbed for 100 years was compared to fallout history. The model of {sup 137}Cs distribution rate was established to estimate fallout history from soil samples. (J.P.N.)

  16. Foundation Fireworks CS4

    CERN Document Server

    Smith, N; Heerema, Matt; Mallott, Chuch; King, R; Erskine, Craig

    2009-01-01

    Are you a web designer who is looking for a new and quicker way to prototype and create for the web? Perhaps you are a programmer who finds most design tools to be overkill for what you need to get done. Or, maybe you're an old Fireworks pro, who wants to keep up to date on the latest changes in Creative Suite 4. Either way, this book has something for you. * Coverage of all that's new and powerful for the Web designer and developer in Fireworks CS4* Targets developers who want design tools that don't get in their way and designers who want development tools that don't constrain their creativi

  17. Frameworks in CS1

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak; Caspersen, Michael Edelgaard

    2002-01-01

    point for introducing graphical user interface frameworks such as Java Swing and AWT as the students are not overwhelmed by all the details of such frameworks right away but given a conceptual road-map and practical experience that allow them to cope with the complexity.......In this paper we argue that introducing object-oriented frameworks as subject already in the CS1 curriculum is important if we are to train the programmers of tomorrow to become just as much software reusers as software producers. We present a simple, graphical, framework that we have successfully...... used to introduce the principles of object-oriented frameworks to students at the introductory programming level. Our framework, while simple, introduces central abstractions such as inversion of control, event-driven programming, and variability points/hot-spots. This has provided a good starting...

  18. Mechanical design and construction qualification program on ITER correction coils structures

    Energy Technology Data Exchange (ETDEWEB)

    Foussat, A., E-mail: arnaud.foussat@iter.org [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Weiyue, Wu; Jing, Wei; Shuangsong, Du [Academy of Science Institute of Plasma Physics, PO 1126, Hefei, Anhui 230031 (China); Sgobba, S. [European Center for Nuclear Research, CH-1211 Geneva 23 (Switzerland); Hongwei, Li [China International Nuclear Fusion Energy Program Execution Center, Ministry of Science and Technology, 15B Fuxing Rd., Beijing 100862 (China); Libeyre, Paul; Jong, Cornelis; Klofac, Kamil; Mitchell, Neil [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France)

    2014-04-01

    The ITER Magnet system consists of 4 main coils sub-systems, i.e. 18 toroidal field coils (TFC), a central solenoid (CS), 6 poloidal field coils (PF) and 3 sets of correction coils (CC). The ITER fusion project has selected the stainless steel 316LN as main material for the magnet structure. The CC contribute to reducing the range of magnetic error fields created by imperfections in the location and geometry of the other coils used to confine, heat, and shape the plasma. During plasma operation, a large number of loading condition scenarios have been considered and structural analysis performed on key items like Cable-In-Conduit Conductor and the coil case. The results obtained are used for both static and fatigue structural assessment defining the present baseline design. For the construction of the structural cases, welding techniques such as GTAW (Gas Tungsten Arc Welding) and techniques resulting in low distortion and shrinkage like EBW (Electron Beam Welding) or Laser Beam Welding (LBW) with filler metal wire have been selected. Those methods are considered for future qualifications to guarantee proper weld parameters and specified weld properties. In order to determine the strength and fracture toughness of 316LN stainless steel welds with respect to design criteria, some mechanical tests have been carried out at 7 K (or 77 K), and room temperature.

  19. Bow-shaped toroidal field coils

    International Nuclear Information System (INIS)

    Bonanos, P.

    1981-05-01

    Design features of Bow-Shaped Toroidal Field Coils are described and compared with circular and D shaped coils. The results indicate that bow coils can produce higher field strengths, store more energy and be made demountable. The design offers the potential for the production of ultrahigh toroidal fields. Included are representative coil shapes and their engineering properties, a suggested structural design and an analysis of a specific case

  20. Analytical solutions to SSC coil end design

    International Nuclear Information System (INIS)

    Bossert, R.C.; Brandt, J.S.; Carson, J.A.; Fulton, H.J.; Lee, G.C.; Cook, J.M.

    1989-03-01

    As part of the SCC magnet effort, Fermilab will build and test a series of one meter model SSC magnets. The coils in these magnets will be constructed with several different end configurations. These end designs must satisfy both mechanical and magnetic criteria. Only the mechanical problem will be addressed. Solutions will attempt to minimize stresses and provide internal support for the cable. Different end designs will be compared in an attempt to determine which is most appropriate for the SSC dipole. The mathematics required to create each end configuration will be described. The computer aided design, programming and machine technology needed to make the parts will be reviewed. 2 refs., 10 figs

  1. Plasmodium vivax antigen discovery based on alpha-helical coiled coil protein motif

    DEFF Research Database (Denmark)

    Céspedes, Nora; Habel, Catherine; Lopez-Perez, Mary

    2014-01-01

    Protein α-helical coiled coil structures that elicit antibody responses, which block critical functions of medically important microorganisms, represent a means for vaccine development. By using bioinformatics algorithms, a total of 50 antigens with α-helical coiled coil motifs orthologous to Pla...

  2. Sensitive quench detection of the HTS coil using a co-winding coil

    International Nuclear Information System (INIS)

    Takagi, Tomohiro; Ariyama, Takahiro; Takao, Tomoaki; Tsukamoto, Osami

    2017-01-01

    The authors have studied the co-winding coil method (CW method) using the co-wound coil electrically insulated from the HTS coil. In this method, the quench is detected by the voltage difference between the coil of the HTS tape (HTS coil) and the coil of the normal conductor (CW coil). The voltage induced in the CW coil caused by the change of the magnetic field is almost the same as that in the HTS coil because the coils are magnetically coupled close to each other. Therefore, it is expected that the induced voltage will be canceled with high accuracy and that the resistive voltage in the HTS coil will be detected with greater sensitivity compared to the bridge balance method, which is used commonly. In this study, quench detection applying the CW method is demonstrated using an experimental double-pancake coil. A tape with the copper layer deposited on the polymer substrate was used as the insulated conductor wire to form the CW coil. An additional pancake coil was used to expose the experimental double-pancake coil to the external magnetic field asymmetrically. It was shown that the CW method can detect the resistive voltage with greater sensitivity even when the HTS coil was exposed to the changing asymmetric external magnetic field. (author)

  3. Status of the Swiss LCT-coil

    International Nuclear Information System (INIS)

    Zichy, J; Benz, H.; Horvath, I.; Jakob, B.; Marinucci, C.; Vecsey, G.; Weymuth, P.; Zellweger, J.

    1983-01-01

    The Swiss coil is a forced flow coil cooled by supercritical helium. A brief review of the design considerations, some of its specific features, and the progress in fabrication are described. A discussion of both the instrumentation and the cryogenic characteristics of the coil is presented

  4. Linear motor coil assembly and linear motor

    NARCIS (Netherlands)

    2009-01-01

    An ironless linear motor (5) comprising a magnet track (53) and a coil assembly (50) operating in cooperation with said magnet track (53) and having a plurality of concentrated multi-turn coils (31 a-f, 41 a-d, 51 a-k), wherein the end windings (31E) of the coils (31 a-f, 41 a-e) are substantially

  5. Split Coil Forms for Rotary Transformers

    Science.gov (United States)

    Mclyman, C. W. T.

    1982-01-01

    Split cores for rotor and stator windings of rotary transformer mounted around their respective coils (which are in bobbins) and cemented together. This arrangement simplifies winding of stator coil to go in a slot in inner diameter of stator coil. One practical application of rotary transformers fabricated according to this technique is for centrifuges, in which conventional sliprings are of uncertain reliability.

  6. Startup of large coil test facility

    International Nuclear Information System (INIS)

    Haubenreich, P.N.; Bohanan, R.E.; Fietz, W.A.; Luton, J.N.; May, J.R.

    1984-01-01

    The Large Coil Test Facility (LCTF) is being used to test superconducting toroidal field coils about one-third the size of those for INTOR. Data were obtained on performance of refrigerator, helium distribution, power supplies, controls, and data acquisition systems and on the acoustic emission, voltages, currents, and mechanical strains during charging and discharging the coils. (author)

  7. Novel method of aligning ATF-1 coils

    International Nuclear Information System (INIS)

    Rome, J.A.; Harris, J.H.; Neilson, G.H.; Jernigan, T.C.

    1983-08-01

    The coils for the Advanced Toroidal Facility (ATF-1) torsatron may be easily aligned before the machine is placed under vacuum. This is done by creating nulls in the magnetic field by energizing the coils in various configurations. All of the nulls in vertical bar B vector vertical bar occur on the z-axis. When the nulls coincide, the coils are properly aligned

  8. Self-Assembly of Rod-Coil Block Copolymers

    National Research Council Canada - National Science Library

    Jenekhe, S

    1999-01-01

    ... the self-assembly of new rod-coil diblock, rod- coil-rod triblock, and coil-rod-coil triblock copolymers from solution and the resulting discrete and periodic mesostmctares with sizes in the 100...

  9. The Permanent Magnet Operating Mechanism of Double Coil Parallel Driven at a High Speed

    Directory of Open Access Journals (Sweden)

    WEI Xau-Lao

    2017-02-01

    Full Text Available Abstract:Operating mechanism is the main part of breaker,and the quality of breaker will directly influence the safe operation of power system. Because of the continuous improvement requirements of switch,in order to mak this actuator faster and more powerful closing,this paper proposes a double coil parallel driven permanent magnet actuator at a high speed. This paper expounds the working principle of single and double coil parallel driven permanent magnet actuator. It uses Ansoft building model and contrasts test results. In prance we designed and produced the single and double coil parallel driven permanent magnet actuator for experimental study. The simulation and experiment results show that double coil parallel driven permanent magnet actuator,compared with single coil parallel driven permanent magnet actuator,has a better and faster action performance. Thus,the double coil parallel driven permanent magnet actuator achieves a kind of optimization.

  10. A 1.5 MJ cryostatic stable superconducting ohmic-heating coil

    International Nuclear Information System (INIS)

    Wang, S.-T.; Kim, S.H.; Praeg, W.F.; Krieger, C.I.

    1978-01-01

    As early as FY 1975, ANL had recognized the clear advantage of a superconducting ohmic-heating (OH) coil and proposed a five-year pulsed coil and power supply development program to ERDA. With modest funding made available by ERDA in FY 1977 and the use of substantial equipment inventory at ANL, a small but agressive development program was advanced to the construction of a 1.5 MJ model coil. The principle objective in building the 1.5 MJ ac coil is to demonstrate ac cryostability of a large coil with a dB/dt ranging from 2 T/s up to 14 T/s. The results of basic cable development and tests will be described. The design and construction of a prototype 1.5 MJ cryostable pulsed coil and its nonmetallic cryostat will be presented. (author)

  11. Performance of long J-shaped coils in large and giant intracranial aneurysms: an in vitro study

    International Nuclear Information System (INIS)

    Tokunaga, K.; Tanaka, N.; Sugiu, K.; Levrier, O.; Martin, J.B.; Ruefenacht, D.A.

    2002-01-01

    We evaluated the performance of long straight coils (Detach-18 trademark J-shaped coils) in large and giant in-vitro aneurysms. The coils consisted of a distal semicircular part 7 or 15 mm in diameter and a proximal 70 cm straight part having three types of stiffness: soft, standard, and stiff. We first investigated the ease of passage through a microcatheter in a realistic cerebral vessel model. Second, we made silicone models simulating lateral-type aneurysms of various spherical dome diameters (12, 15, 20 and 30 mm) and neck sizes (3-10 mm; dome-to-neck ratio approximately 3:1) and connected them to a pulsating circulatory pump. We evaluated the anchoring and folding patterns of the coils, stability of the microcatheter and coils in the aneurysm, and smoothness of delivery and retrieval of coils. Third, we compared the conformability of a coil in a large, irregular aneurysm with that of a spiral coil. The long J-shaped coils were easily advanced and retrieved through a microcatheter in a tortuous vessel model. In 12 mm spherical aneurysms, each coil made a complex framework, and knot formation or damage to the coil during withdrawal was often observed. In 15 mm aneurysms, the coils were all easily delivered and retrieved; standard-stiffness coils adapted best to this size. In 20 mm aneurysms, frameworks were less complex but still good with a standard or stiff coil, but those with soft coil were unstable and changed significantly within 3 min of detachment due to gravity and pulsatile flow. In 30 mm aneurysms, soft coils filled only the lower part during introduction, whereas a stiff coil still made a favourable framework. Conformability of a long J-shaped coil was superior to that of a spiral coil in a large, irregular aneurysm. Long J-shaped coils conform well to various configurations of large and giant aneurysms and can shorten procedures since a larger implant volume can be delivered with a single coil. Their principle of action may promote more favourable

  12. Compensation of the ux modulation distortion using an additional coil in a loudspeaker unit

    DEFF Research Database (Denmark)

    Antonello, Niccoló; Agerkvist, Finn T.

    2014-01-01

    Flux modulation is one of the main causes of distortion in electrodynamic loudspeaker units. A new com- pensation technique that eliminates this type of non-linearity using an additional compensation coil in the speaker unit is presented. An equivalent circuit model of the device including...... the compensation coil is de- rived. The compensation technique consists on feeding the compensation coil and voice coil with ltered versions of the wanted audio signal. Simulations show that a signicant reduction in ux modulation distor- tion can be achieved with this technique. A simple magnetic circuit has been...

  13. Compensation of the flux modulation distortion using an additional coil in a loudspeaker unit

    DEFF Research Database (Denmark)

    Antonello, Niccoló; Agerkvist, Finn T.

    2014-01-01

    the compensation coil is derived. The compensation technique consists on feeding the compensation coil and voice coil with filtered versions of the wanted audio signal. Simulations show that a significant reduction in flux modulation distortion can be achieved with this technique. A simple magnetic circuit has......Flux modulation is one of the main causes of distortion in electrodynamic loudspeaker units. A new compensation technique that eliminates this type of non-linearity using an additional compensation coil in the speaker unit is presented. An equivalent circuit model of the device including...

  14. Differences between two definitions of the critical current of HTS coils

    International Nuclear Information System (INIS)

    Pitel, Jozef

    2013-01-01

    Definition of the critical current of a coil made of anisotropic high temperature superconducting conductor is rather complicated and ambiguous, since the magnetic field generated across the winding can differ considerably in relation to both its magnitude and orientation. Two definitions of the critical current of such coils are discussed. The first definition, very often used in calculations to analyze the current carrying capacity, electric field and power dissipation of individual turns, represents an operating current at which an electric field of 1 μV cm −1 appears on one turn. The second definition represents an integral approach, and is used in experiments. This definition introduces the critical current of the coil as an operating current at which an average electric field E s , usually 0.1 μV cm −1 , appears on coil terminals. As an example, the distribution of the critical current and electric field of individual turns in the winding of a BSCCO model coil was analyzed. Critical currents of the coil as a function of an external magnetic field parallel with the coil axis were calculated according to both definitions. The results show that the first definition, which characterizes the winding at the local level, is suitable for HTS coils either operating in self-field or in a low external field, because the differences between the critical currents and n-indices of individual turns are considerable. The second criterion is suitable for the HTS coils operating in high fields, i.e. like high field insert coils. The self-field of a high field insert coil is negligible if the external field is high. As a result, the critical currents of all turns are almost identical, and the anisotropy in I c (B) characteristic plays practically no role. Rather unexpected behavior of the voltage–current characteristic of the model coil is predicted if an external field is applied. (paper)

  15. Coil Migration through a Neuroform 3 Stent during Endovascular Coiling. A Case Report.

    LENUS (Irish Health Repository)

    O'Hare, A

    2009-07-29

    Summary: A 43-year-old woman attended for stent assisted coiling. A Neuroform 30 x 4.5 mm stent had been successfully placed over the left periophthalmic aneurysm. During the coiling the first coil migrated through the crowns in the stent, lodging at the MCA bifurcation. We believe that the coil herniated through the overlying stent due to the carotid siphon curvature and the open cell design. Furthermore the distal markers of the stent impeded coil extraction with a MERCI device.

  16. An inflatable surface coil for rectal imaging

    International Nuclear Information System (INIS)

    Martin, J.F.; Hajek, P.C.; Baker, L.L.; Gylys-Morin, V.; Mattrey, R.F.

    1986-01-01

    Surface coils have become ubiquitous in MR imaging of the body because of substantial gains in signal-to-noise ratio. Unfortunately, there are some anatomic regions, such as the prostate, for which surface coils have insufficient depth sensitivity. The authors have developed an inflatable, distributed capacitance, passively decoupled surface coil which is collapsed for insertion and reinflated for imaging. Images of the prostate are dramatically improved due to proximity of the coil. Lesions in cadaver specimens were observed which were not seen with body coil imaging. Clinical trials are expected to begin in September

  17. Pulse coil concepts for the LCP Facility

    International Nuclear Information System (INIS)

    Nelson, B.E.; Burn, P.B.

    1977-01-01

    The pulse coils described in this paper are resistive copper magnets driven by time-varying currents. They are included in the Large Coil Test Facility (LCTF) portion of the Large Coil Program (LCP) to simulate the pulsed field environment of the toroidal coils in a tokamak reactor. Since TNS (a 150 sec, 5MA, igniting tokamak) and the Oak Ridge EPR (Experimental Power Reactor) are representative of the first tokamaks to require the technology developed in LCP, the reference designs for these machines, especially TNS, are used to derive the magnetic criteria for the pulse coils. This criteria includes the magnitude, distribution, and rate of change of pulsed fields in the toroidal coil windings. Three pulse coil concepts are evaluated on the basis of magnetic criteria and factors such as versatility of design, ease of fabrication and cost of operation. The three concepts include (1) a pair of poloidal coils outside the LCTF torus, (2) a single poloidal coil threaded through the torus, and (3) a pair of vertical axis coil windings inside the bore of one or more of the toroidal test coils

  18. Performance evaluation of matrix gradient coils.

    Science.gov (United States)

    Jia, Feng; Schultz, Gerrit; Testud, Frederik; Welz, Anna Masako; Weber, Hans; Littin, Sebastian; Yu, Huijun; Hennig, Jürgen; Zaitsev, Maxim

    2016-02-01

    In this paper, we present a new performance measure of a matrix coil (also known as multi-coil) from the perspective of efficient, local, non-linear encoding without explicitly considering target encoding fields. An optimization problem based on a joint optimization for the non-linear encoding fields is formulated. Based on the derived objective function, a figure of merit of a matrix coil is defined, which is a generalization of a previously known resistive figure of merit for traditional gradient coils. A cylindrical matrix coil design with a high number of elements is used to illustrate the proposed performance measure. The results are analyzed to reveal novel features of matrix coil designs, which allowed us to optimize coil parameters, such as number of coil elements. A comparison to a scaled, existing multi-coil is also provided to demonstrate the use of the proposed performance parameter. The assessment of a matrix gradient coil profits from using a single performance parameter that takes the local encoding performance of the coil into account in relation to the dissipated power.

  19. Activity standardization of 134Cs and 137Cs

    International Nuclear Information System (INIS)

    Sochorová, Jana; Auerbach, Pavel

    2014-01-01

    The paper presents the results from a primary standardization of 137 Cs using two independent methods – efficiency tracing using PC-NaI coincidence and the TDCR method. The nuclides 60 Co and 134 Cs were used as the tracers. Primary standardization of the 134 Cs is also discussed. The efficiency extrapolation was carried out by measuring samples of varying mass and using the wet extrapolation method. The results obtained are in good agreement; the differences did not exceed 0.5%. The advantages, pitfalls and also possibilities for improvement of the procedures are discussed

  20. Coiled transmission line pulse generators

    Science.gov (United States)

    McDonald, Kenneth Fox

    2010-11-09

    Methods and apparatus are provided for fabricating and constructing solid dielectric "Coiled Transmission Line" pulse generators in radial or axial coiled geometries. The pour and cure fabrication process enables a wide variety of geometries and form factors. The volume between the conductors is filled with liquid blends of monomers, polymers, oligomers, and/or cross-linkers and dielectric powders; and then cured to form high field strength and high dielectric constant solid dielectric transmission lines that intrinsically produce ideal rectangular high voltage pulses when charged and switched into matched impedance loads. Voltage levels may be increased by Marx and/or Blumlein principles incorporating spark gap or, preferentially, solid state switches (such as optically triggered thyristors) which produce reliable, high repetition rate operation. Moreover, these Marxed pulse generators can be DC charged and do not require additional pulse forming circuitry, pulse forming lines, transformers, or an a high voltage spark gap output switch. The apparatus accommodates a wide range of voltages, impedances, pulse durations, pulse repetition rates, and duty cycles. The resulting mobile or flight platform friendly cylindrical geometric configuration is much more compact, light-weight, and robust than conventional linear geometries, or pulse generators constructed from conventional components. Installing additional circuitry may accommodate optional pulse shape improvements. The Coiled Transmission Lines can also be connected in parallel to decrease the impedance, or in series to increase the pulse length.

  1. Comparison of the induced fields using different coil configurations during deep transcranial magnetic stimulation.

    Directory of Open Access Journals (Sweden)

    Mai Lu

    Full Text Available Stimulation of deeper brain structures by transcranial magnetic stimulation (TMS plays a role in the study of reward and motivation mechanisms, which may be beneficial in the treatment of several neurological and psychiatric disorders. However, electric field distributions induced in the brain by deep transcranial magnetic stimulation (dTMS are still unknown. In this paper, the double cone coil, H-coil and Halo-circular assembly (HCA coil which have been proposed for dTMS have been numerically designed. The distributions of magnetic flux density, induced electric field in an anatomically based realistic head model by applying the dTMS coils were numerically calculated by the impedance method. Results were compared with that of standard figure-of-eight (Fo8 coil. Simulation results show that double cone, H- and HCA coils have significantly deep field penetration compared to the conventional Fo8 coil, at the expense of induced higher and wider spread electrical fields in superficial cortical regions. Double cone and HCA coils have better ability to stimulate deep brain subregions compared to that of the H-coil. In the mean time, both double cone and HCA coils increase risk for optical nerve excitation. Our results suggest although the dTMS coils offer new tool with potential for both research and clinical applications for psychiatric and neurological disorders associated with dysfunctions of deep brain regions, the selection of the most suitable coil settings for a specific clinical application should be based on a balanced evaluation between stimulation depth and focality.

  2. An analysis of England's nursing policy on compassion and the 6Cs: the hidden presence of M. Simone Roach's model of caring.

    Science.gov (United States)

    Bradshaw, Ann

    2016-03-01

    In 2012, chief nursing officers (CNO) in England published a policy on compassion in response to serious criticisms of patients' care. Because their objective is fundamentally to shape nursing, this study argues, following Popper, that the policy should be analysed. An appraisal tool, developed from Popper, Gadamer, Jauss and Thiselton, is the framework for this analysis. The CNO policy document identified six values and behaviours, termed '6Cs', required by all nurses, midwives and care staff. The document contains no data, references or acknowledgements, but is similar to the 6Cs defined by the Canadian nursing nun, Sister M. Simone Roach, in her theory of caring published 30 years earlier. Roach considered caring and the components of it, including compassion, to be moral virtues, an inner motivation to care. This study suggests that without explicit reference to Roach's ideas, and her underlying theoretical base, the CNO requirement has the effect of turning virtues into commodities and a form of external control, described by Ritzer as a McDonaldized dehumanization. This study, which has international relevance beyond England and the UK, suggests that the CNO revise their policy by acknowledging Roach's 6Cs and openly discuss the implications of her work for their policy. © 2015 John Wiley & Sons Ltd.

  3. Equivalent Coil Model for Computing Levitation Forces Between Permanent Magnets and High Temperatures Superconductors; Modelo de Espira Equivalente para el Calculo de Fuerzas de Levitacion Magnetica entre Imanes Permanentes y Superconductores de Alta Temperatura Critica

    Energy Technology Data Exchange (ETDEWEB)

    Cavia Santos, S; Garcia-Tabares, L

    1998-05-01

    A new simple theory has been developed for the study of levitation forces between a permanent magnet and a HTc superconductor. This theory is based on the assumption that both, the magnet and the superconductor, can be modelled by an equivalent coil placed on their surface. While the current flowing through the permanent magnet is constant, the equivalent current through the superconductor can be iether corresponding to screen the overall flux or a constant current corresponding to critical current density when the superconductor is saturated. A test facility has been designed and built for measuring levitation forces at variable approaching speeds. Comparison between theoretical and experimental measurements are presented in the report as well as a general description of the test facility. (Author)

  4. Enhancing the design of a superconducting coil for magnetic energy storage systems

    International Nuclear Information System (INIS)

    Indira, Gomathinayagam; UmaMaheswaraRao, Theru; Chandramohan, Sankaralingam

    2015-01-01

    Highlights: • High magnetic flux density of SMES coil to reduce the size. • YBCO Tapes for the construction of HTS magnets. • Relation between energy storage and length of the coil wound by various materials. • Design with a certain length of second-generation HTS. - Abstract: Study and analysis of a coil for Superconducting Magnetic Energy Storage (SMES) system is presented in this paper. Generally, high magnetic flux density is adapted in the design of superconducting coil of SMES to reduce the size of the coil and to increase its energy density. With high magnetic flux density, critical current density of the coil is degraded and so the coil is wound with High Temperature Superconductors (HTS) made of different materials. A comparative study is made to emphasize the relationship between the energy storage and length of the coil wound by Bi2223, SF12100, SCS12100 and YBCO tapes. Recently for the construction of HTS magnets, YBCO tapes have been used. Simulation models for various designs have been developed to analyze the magnetic field distribution for the optimum design of energy storage. The design which gives the maximum stored energy in the coil has been used with a certain length of second-generation HTS. The performance analysis and the results of comparative study are done

  5. Enhancing the design of a superconducting coil for magnetic energy storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Indira, Gomathinayagam, E-mail: gindu80@gmail.com [EEE Department, Prince Shri Venkateshwara Padmavathy Engineering College, Chennai (India); UmaMaheswaraRao, Theru, E-mail: umesh.theru@gmail.com [Divison of Power Engineering and Management, Anna University, Chennai (India); Chandramohan, Sankaralingam, E-mail: cdramo@gmail.com [Divison of Power Engineering and Management, Anna University, Chennai (India)

    2015-01-15

    Highlights: • High magnetic flux density of SMES coil to reduce the size. • YBCO Tapes for the construction of HTS magnets. • Relation between energy storage and length of the coil wound by various materials. • Design with a certain length of second-generation HTS. - Abstract: Study and analysis of a coil for Superconducting Magnetic Energy Storage (SMES) system is presented in this paper. Generally, high magnetic flux density is adapted in the design of superconducting coil of SMES to reduce the size of the coil and to increase its energy density. With high magnetic flux density, critical current density of the coil is degraded and so the coil is wound with High Temperature Superconductors (HTS) made of different materials. A comparative study is made to emphasize the relationship between the energy storage and length of the coil wound by Bi2223, SF12100, SCS12100 and YBCO tapes. Recently for the construction of HTS magnets, YBCO tapes have been used. Simulation models for various designs have been developed to analyze the magnetic field distribution for the optimum design of energy storage. The design which gives the maximum stored energy in the coil has been used with a certain length of second-generation HTS. The performance analysis and the results of comparative study are done.

  6. Magnetic resonance imaging of rodent spinal cord with an improved performance coil at 7 Tesla

    Science.gov (United States)

    Solis-Najera, S. E.; Rodriguez, A. O.

    2014-11-01

    Magnetic Resonance Imaging of animal models provide reliable means to study human diseases. The image acquisition particularly determined by the radio frequency coil to detect the signal emanated from a particular region of interest. A scaled-down version of the slotted surface coil was built based on the previous results of a magnetron-type surface coil for human applications. Our coil prototype had a 2 cm total diameter and six circular slots and was developed for murine spinal cord at 7 T. Electromagnetic simulations of the slotted and circular coils were also performed to compute the spatially dependent magnetic and electric fields using a simulated saline-solution sphere. The quality factor of both coils was experimentally measured giving a lower noise figure and a higher quality factor for the slotted coil outperforming the circular coil. Images of the spinal cord of a rat were acquired using standard pulse sequences. The slotted surface coil can be a good tool for spinal cord rat imaging using conventional pulse sequences at 7 T.

  7. Conformational switching in the coiled-coil domains of a proteasomal ATPase regulates substrate processing.

    Science.gov (United States)

    Snoberger, Aaron; Brettrager, Evan J; Smith, David M

    2018-06-18

    Protein degradation in all domains of life requires ATPases that unfold and inject proteins into compartmentalized proteolytic chambers. Proteasomal ATPases in eukaryotes and archaea contain poorly understood N-terminally conserved coiled-coil domains. In this study, we engineer disulfide crosslinks in the coiled-coils of the archaeal proteasomal ATPase (PAN) and report that its three identical coiled-coil domains can adopt three different conformations: (1) in-register and zipped, (2) in-register and partially unzipped, and (3) out-of-register. This conformational heterogeneity conflicts with PAN's symmetrical OB-coiled-coil crystal structure but resembles the conformational heterogeneity of the 26S proteasomal ATPases' coiled-coils. Furthermore, we find that one coiled-coil can be conformationally constrained even while unfolding substrates, and conformational changes in two of the coiled-coils regulate PAN switching between resting and active states. This switching functionally mimics similar states proposed for the 26S proteasome from cryo-EM. These findings thus build a mechanistic framework to understand regulation of proteasome activity.

  8. 1+ collective states of 124Cs and 126Cs nuclei

    International Nuclear Information System (INIS)

    Ivanova, S.P.; Kuliev, A.A.; Salamov, D.I.

    1977-01-01

    Within the framework of the random phase approximation β-decay properties of the 1 + states of 124 Cs and 126 Cs have been investigated. Greatly collectivized 1 + states in odd-odd nuclei are produced by the spin-dependent charge-exchange nucleon interaction. For numerical calculations the scheme of single-particle levels in the deformed Saxon-Woods potential has been used

  9. Simulations of the transport and deposition of {sup 137}Cs over Europe after the Chernobyl Nuclear Power Plant accident. Influence of varying emission-altitude and model horizontal and vertical resolution

    Energy Technology Data Exchange (ETDEWEB)

    Evangeliou, N.; Balkanski, Y.; Cozic, A. [Institut Pierre et Simon Laplace, Gif sur Yvette (France). Lab. des Sciences du Climat et de l' Environnement; Moeller, A.P. [Univ. Paris-Sud, Orsay (France). Lab. d' Ecologie, Systematique et Evolution

    2013-07-01

    The coupled model LMDZORINCA has been used to simulate the transport, wet and dry deposition of the radioactive tracer {sup 137}Cs after accidental releases. For that reason, two horizontal resolutions were deployed and used in the model, a regular grid of 2.5 x 1.27 , and the same grid stretched over Europe to reach a resolution of 0.66 x 0.51 . The vertical dimension is represented with two different resolutions, 19 and 39 levels respectively, extending up to the mesopause. Four different simulations are presented in this work; the first uses the regular grid over 19 vertical levels assuming that the emissions took place at the surface (RG19L(S)), the second also uses the regular grid over 19 vertical levels but realistic source injection heights (RG19L); in the third resolution the grid is regular and the vertical resolution 39 levels (RG39L) and finally, it is extended to the stretched grid with 19 vertical levels (Z19L). The model is validated with the Chernobyl accident which occurred in Ukraine (ex-USSR) on 26 May 1986 using the emission inventory from Brandt et al. (2002). This accident has been widely studied since 1986, and a large database has been created containing measurements of atmospheric activity concentration and total cumulative deposition for {sup 137}Cs from most of the European countries. According to the results, the performance of the model to predict the transport and deposition of the radioactive tracer was efficient and accurate presenting low biases in activity concentrations and deposition inventories, despite the large uncertainties on the intensity of the source released. The best agreement with observations was obtained using the highest horizontal resolution of the model (Z19L run). The model managed to predict the radioactive contamination in most of the European regions (similar to De Cort et al., 1998), and also the arrival times of the radioactive fallout. As regards to the vertical resolution, the largest biases were obtained

  10. Simulations of the transport and deposition of "1"3"7Cs over Europe after the Chernobyl Nuclear Power Plant accident. Influence of varying emission-altitude and model horizontal and vertical resolution

    International Nuclear Information System (INIS)

    Evangeliou, N.; Balkanski, Y.; Cozic, A.; Moeller, A.P.

    2013-01-01

    The coupled model LMDZORINCA has been used to simulate the transport, wet and dry deposition of the radioactive tracer "1"3"7Cs after accidental releases. For that reason, two horizontal resolutions were deployed and used in the model, a regular grid of 2.5 x 1.27 , and the same grid stretched over Europe to reach a resolution of 0.66 x 0.51 . The vertical dimension is represented with two different resolutions, 19 and 39 levels respectively, extending up to the mesopause. Four different simulations are presented in this work; the first uses the regular grid over 19 vertical levels assuming that the emissions took place at the surface (RG19L(S)), the second also uses the regular grid over 19 vertical levels but realistic source injection heights (RG19L); in the third resolution the grid is regular and the vertical resolution 39 levels (RG39L) and finally, it is extended to the stretched grid with 19 vertical levels (Z19L). The model is validated with the Chernobyl accident which occurred in Ukraine (ex-USSR) on 26 May 1986 using the emission inventory from Brandt et al. (2002). This accident has been widely studied since 1986, and a large database has been created containing measurements of atmospheric activity concentration and total cumulative deposition for "1"3"7Cs from most of the European countries. According to the results, the performance of the model to predict the transport and deposition of the radioactive tracer was efficient and accurate presenting low biases in activity concentrations and deposition inventories, despite the large uncertainties on the intensity of the source released. The best agreement with observations was obtained using the highest horizontal resolution of the model (Z19L run). The model managed to predict the radioactive contamination in most of the European regions (similar to De Cort et al., 1998), and also the arrival times of the radioactive fallout. As regards to the vertical resolution, the largest biases were obtained for

  11. Simulations of the transport and deposition of 137Cs over Europe after the Chernobyl Nuclear Power Plant accident: influence of varying emission-altitude and model horizontal and vertical resolution

    Science.gov (United States)

    Evangeliou, N.; Balkanski, Y.; Cozic, A.; Møller, A. P.

    2013-07-01

    The coupled model LMDZORINCA has been used to simulate the transport, wet and dry deposition of the radioactive tracer 137Cs after accidental releases. For that reason, two horizontal resolutions were deployed and used in the model, a regular grid of 2.5° × 1.27°, and the same grid stretched over Europe to reach a resolution of 0.66° × 0.51°. The vertical dimension is represented with two different resolutions, 19 and 39 levels respectively, extending up to the mesopause. Four different simulations are presented in this work; the first uses the regular grid over 19 vertical levels assuming that the emissions took place at the surface (RG19L(S)), the second also uses the regular grid over 19 vertical levels but realistic source injection heights (RG19L); in the third resolution the grid is regular and the vertical resolution 39 levels (RG39L) and finally, it is extended to the stretched grid with 19 vertical levels (Z19L). The model is validated with the Chernobyl accident which occurred in Ukraine (ex-USSR) on 26 May 1986 using the emission inventory from Brandt et al. (2002). This accident has been widely studied since 1986, and a large database has been created containing measurements of atmospheric activity concentration and total cumulative deposition for 137Cs from most of the European countries. According to the results, the performance of the model to predict the transport and deposition of the radioactive tracer was efficient and accurate presenting low biases in activity concentrations and deposition inventories, despite the large uncertainties on the intensity of the source released. The best agreement with observations was obtained using the highest horizontal resolution of the model (Z19L run). The model managed to predict the radioactive contamination in most of the European regions (similar to De Cort et al., 1998), and also the arrival times of the radioactive fallout. As regards to the vertical resolution, the largest biases were obtained for

  12. Quench and protection characteristics of the GEM test coil

    International Nuclear Information System (INIS)

    Chaniotakis, E.A.; Marston, P.G.

    1994-01-01

    The GEM test coil, will be wound from 70 m of conductor identical to that used in the full scale magnet. The coil configuration will duplicate the field distribution of the full scale magnet and current control will duplicate full scale current decay characteristics. Therefore, quench/protection analysis of this coil will reveal very important information about the behavior of the full scale model. Due to the uncertainty associated with the contact between the cable, the conduit and the sheath, a parametric analysis has been performed in order to determine and bracket the behavior. With no electrical contact the quench evolves normally until, due to heat transfer from the sheath into the cable, the superconductor temperature becomes critical and the entire length becomes normal

  13. Thermal analysis of laser welding for ITER correction coil case

    Energy Technology Data Exchange (ETDEWEB)

    Fang, C., E-mail: fangchao@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 200031 (China); Lappeenranta University of Technology, Skinnarilankatu 34, 53850 Lappeenranta (Finland); Song, Y.T.; Wu, W.Y.; Wei, J.; Xin, J.J. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 200031 (China); Wu, H.P.; Salminen, A. [Lappeenranta University of Technology, Skinnarilankatu 34, 53850 Lappeenranta (Finland)

    2015-11-15

    Highlights: • Morphology of simulated heat source is found to be close to the welded joint sample. • The FEA temperature distribution shows good agreement with experimental measurements. • Laser welding process used on ITER correction coil case will not harm the winding pack. - Abstract: This paper presents the simulation results of 3D finite element analysis (FEA) of laser welding processes for the ITER correction coil case welding; predicts the temperature distribution and compares it with the experimental result to evaluate the impact to the properties of winding pack during the welding process. A specimen of coil case was modeled and simulated by using specialized welding simulation software SYSWELD, Modeling used austenitic stainless steel 316LN as the specimen material and a 3D Conical Gaussian was used as a heat source model. A plate sample was welded before the FE modeling in order to obtain the laser welding parameters and the Gaussian parameters of molten pool. To verify the simulation results, a coil case sample was welded using laser welding with welding parameters that matched the model, and the corresponding temperature values were measured using thermocouples. Compared with the FEA results, it was found that the FEA temperature distribution shows good agreement with the experimental measurements and the laser welding process will not harm the winding pack.

  14. Transcranial magnetic stimulation: Improved coil design for deep brain investigation

    Science.gov (United States)

    Crowther, L. J.; Marketos, P.; Williams, P. I.; Melikhov, Y.; Jiles, D. C.; Starzewski, J. H.

    2011-04-01

    This paper reports on a design for a coil for transcranial magnetic stimulation. The design shows potential for improving the penetration depth of the magnetic field, allowing stimulation of subcortical structures within the brain. The magnetic and induced electric fields in the human head have been calculated with finite element electromagnetic modeling software and compared with empirical measurements. Results show that the coil design used gives improved penetration depth, but also indicates the likelihood of stimulation of additional tissue resulting from the spatial distribution of the magnetic field.

  15. Dynamics and rheology of finitely extensible polymer coils: An overview

    Science.gov (United States)

    Yao, Donggang

    2017-05-01

    One contemporary research issue in non-Newtonian fluid mechanics is to accurately and effectively model viscoelastic polymer flow of practical relevance. In the past several years, we have been working on the formulation of a finitely extensible coil model for polymer flow, particularly including these elements: (1) decoupled equations for kinematical and dynamical variables, (2) logarithmic relaxation at large deformation, (3) rotational retardation, (4) controllable straining, and (5) finite stretch. In this paper, we provide a constructive overview of this nonlinear coil formulation focusing on integration of these elements in a single, unified constitutive model with a minimal number of model parameters that are linked with corresponding physical processes. We also use this opportunity to share the rationale and thought process in the model development. In one particular implement of the general formulation, three parameters are used to tackle with the principal dynamics of a deforming polymer coil: one for finite stretch dictated by a ceiling stretch of the coil, the second one for rotational recovery/retardation, and the third one for adjusting stretch hardening of the rubbery coil. The new model, even in a single mode, is able to simultaneously predict practical material functions in simple shear and coaxial extension and to fit well to representative experimental data. Particularly in the steady-state (or quasi-steady state) flow case, a nearly closed-form stress to velocity gradient relationship can be derived with which shear thinning and elongational thickening can be simultaneously considered while computational advantages of a classical GNF model is retained. The model also fits reasonably well to representative experimental transient data for both shear and extension.

  16. Knudsen cell mass spectrometric study of the Cs2IOH(g) molecule thermodynamics

    International Nuclear Information System (INIS)

    Roki, F-Z.; Ohnet, M-N.; Fillet, S.; Chatillon, C.; Nuta, I.

    2013-01-01

    Highlights: • The pronounced ionic character leads to only dissociative ionization processes. • Ions formed are same as those coming from pure dimmers. • De-convolution of the ions origin needs accurate thermodynamic values for the pure gas phase. • Mass spectrometric interpretation has to be performed gradually and as a function of suitable condensed compositions. • Thermal functions have to be fully estimated. -- Abstract: The gas phase of the CsI + CsOH system is analyzed by high temperature Knudsen cell mass spectrometry in order to confirm the existence of the Cs 2 IOH(g) complex molecule. The mass spectrometric analysis is quite complex since such molecules undergo dissociative ionization into fragment ions that mix with the same ions from dimers of the pure compounds in the same vapor phase. Varying the chemical conditions for vaporization by using different CsI + CsOH mixture contents showed that the ionization of the Cs 2 IOH(g) molecule led to five different fragment ions, Cs 2 OH + , Cs 2 I + , Cs + , CsOH + and CsI + . This complex ionization pattern was studied in relation with previous assessed values for the vaporization of CsOH and CsI pure compounds in which monomer and dimer molecules are predominant. The equilibrium constant for the reaction CsI(g) + CsOH(g) = Cs 2 IOH(g) was determined and, after modeling the structure of the Cs 2 IOH molecule, the enthalpy of formation was determined using the third law of thermodynamics, as follows: Δ f H°(Cs 2 IOH, g, 298.15 K) = −578 ± 14.7 kJ · mole −1

  17. Modelling of the transfer of Cs-137 from air to crops, milk, beef and human body following the Chernobyl accident in a location in Central Bohemia. Test of the model PRYMA T1

    Energy Technology Data Exchange (ETDEWEB)

    Carrasco, E; Garcia-Olivares, A; Suanez, A; Robles, B; Simon, I; Cancio, D

    1994-07-01

    This work was made in the frame of the research programme on validation od models for the transfer of radionuclides in the terrestrial, urban and aquatic environments. the acronym of this programme is VAMP (Validation of Model Predictions) and is co-ordinated by the International Atomic energy Agency (IAEA) and the Commission of the european Communities (CEC). The scenario was named CB and Was presented by the Multiple Pathway Working group. the scenario description was at the beginning a blind test, that is without knowing the location or the measured concentrations and doses. the input information included data of contamination in Cs-137 from the Chernobyl accident in Central Europe, in air and soils and ore, description of the scenario (data about crops, cattle, demography, human diet, etc.). the aim of the exercise was the contrast between model results and between observed data and model predictions. In this work the results obtained by the CIEMAT-IMA group of modelers are shown and discussed. (Author) 24 refs.

  18. Modelling of the transfer of Cs-137 from air to crops, milk, beef and human body following the Chernobyl accident in a location in Central Bohemia. Test of the model PRYMA T1

    International Nuclear Information System (INIS)

    Carrasco, E.; Garcia-Olivares, A.; Suanez, A.; Robles, B.; Simon, I.; Cancio, D.

    1994-01-01

    This work was made in the frame of the research programme on validation od models for the transfer of radionuclides in the terrestrial, urban and aquatic environments. the acronym of this programme is VAMP (Validation of Model Predictions) and is co-ordinated by the International Atomic energy Agency (IAEA) and the Commission of the european Communities (CEC). The scenario was named CB and Was presented by the Multiple Pathway Working group. the scenario description was at the beginning a blind test, that is without knowing the location or the measured concentrations and doses. the input information included data of contamination in Cs-137 from the Chernobyl accident in Central Europe, in air and soils and ore, description of the scenario (data about crops, cattle, demography, human diet, etc.). the aim of the exercise was the contrast between model results and between observed data and model predictions. In this work the results obtained by the CIEMAT-IMA group of modelers are shown and discussed. (Author) 24 refs

  19. Remote maintenance of tandem mirror hybrid coils

    International Nuclear Information System (INIS)

    Dietz, L.P.

    1983-01-01

    Hybrid Coils (superconducting coils with normal conducting inserts) are being employed with increasing frequency on Tandem Mirror Devices to obtain high field strengths. The normal conducting copper inserts are short lived in comparison to their encircling superconductors. It becomes desirable, therefore, to devise design features and maintenance procedures to replace the inner normal conducting coils without simultaneously replacing the longer lived (and significantly more costly) superconducting coils. The high neutron wall loadings require that the task be accomplished by remote control. The approach is to permanently mount the coil assemblies on track mounted carriages which serve, during machine operation merely as structural supports, but during maintenance procedures as moveable transport devices. The carriages incorporate all necessary provisions to facilitate remote maintenance operations and to adjust and align the coil assemblies with respect to adjacent machine components. The vacuum vessel is severed on both sides of the hybrid coil by means of a remote cutting machine. The entire coil is transported horizontally, normal to the machine axis to a nearby repair station. Prepositioned carriage mounted repair equipment at the repair station withdraws the damaged normal coil as a single entity and inserts a preassembled spare unit. The repaired hybrid coil is reassembled to the reactor. A cost and risk effective procedure has been evolved to maintain one of the more critical components of a Tandem Mirror Machine

  20. Discussion of discrete D shape toroidal coil

    International Nuclear Information System (INIS)

    Kaiho, Katsuyuki; Ohara, Takeshi; Agatsuma, Ko; Onishi, Toshitada

    1988-01-01

    A novel design for a toroidal coil, called the D shape coil, was reported by J. File. The coil conductors are in pure tension and then subject to no bending moment. This leads to a smaller number of emf supports in a simpler configuration than that with the conventional toroidal coil of circular cross-section. The contours of the D shape are given as solutions of a differential equation. This equation includes the function of the magnetic field distribution in the conductor region which is inversely proportional to the winding radius. It is therefore important to use the exact magnetic field distribution. However the magnetic field distribution becomes complicated when the D shape toroidal coil is comprised of discrete coils and also depends on the D shape configuration. A theory and a computer program for designing the practical pure-tension toroidal coil are developed. Using this computer code, D shape conductors are calculated for various numbers of discrete coils and the results are compared. Electromagnetic forces in the coils are also calculated. It is shown that the hoop stress in the conductors depends only on the total ampere-turns of the coil when the contours of the D shape are similar. (author)

  1. Large coil test facility conceptual design report

    International Nuclear Information System (INIS)

    Nelms, L.W.; Thompson, P.B.; Mann, T.L.

    1978-02-01

    In the development of a superconducting toroidal field (TF) magnet for The Next Step (TNS) tokamak reactor, several different TF coils, about half TNS size, will be built and tested to permit selection of a design and fabrication procedure for full-scale TNS coils. A conceptual design has been completed for a facility to test D-shaped TF coils, 2.5 x 3.5-m bore, operating at 4-6 K, cooled either by boiling helium or by forced-flow supercritical helium. Up to six coils can be accommodated in a toroidal array housed in a single vacuum tank. The principal components and systems in the facility are an 11-m vacuum tank, a test stand providing structural support and service connections for the coils, a liquid nitrogen system, a system providing helium both as saturated liquid and at supercritical pressure, coils to produce a pulsed vertical field at any selected test coil position, coil power supplies, process instrumentation and control, coil diagnostics, and a data acquisition and handling system. The test stand structure is composed of a central bucking post, a base structure, and two horizontal torque rings. The coils are bolted to the bucking post, which transmits all gravity loads to the base structure. The torque ring structure, consisting of beams between adjacent coils, acts with the bucking structure to react all the magnetic loads that occur when the coils are energized. Liquid helium is used to cool the test stand structure to 5 K to minimize heat conduction to the coils. Liquid nitrogen is used to precool gaseous helium during system cooldown and to provide thermal radiation shielding

  2. Analysis of quench in the NHMFL REBCO prototype coils for the 32 T Magnet Project

    International Nuclear Information System (INIS)

    Breschi, M; Cavallucci, L; Ribani, P L; Gavrilin, A V; Weijers, H W

    2016-01-01

    A 32 T all-superconductive magnet with high field REBCO inner coils is under development at the National High Magnetic Field Laboratory, Tallahassee, Florida, USA. As part of the development activity, two prototype coils with full scale radial dimensions and final design features, but with reduced axial length were constructed. The prototype coils consist of six dry-wound double pancakes modules with uninsulated conductor and insulated stainless steel cowind. Quench studies on one of the prototype coils at 4.2 K in self-field and in a background magnetic field of 15 T were performed by activating a set of quench protection heaters. In this paper, we present a numerical analysis of the experimental results of the quench tests of one of the prototype coils. The numerical analysis was carried out through a coupled electro-thermal FEM model developed at the University of Bologna. The model is based on the coupling with distributed contact resistances of the coil pancakes described as 2D elements. A homogenization procedure of the REBCO tape and other coil materials is presented, which allows reducing the number of degrees of freedom and the computational effort. The model is applied to the analysis of the current and voltage evolutions during the experimental quench tests on the prototype coil. (paper)