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Start Over Descriptor "exhaust" Journal nuclear fusion
7 results on '"exhaust"'

1. Evaluation of ITER divertor shunts as a synthetic diagnostic for detachment control.

Author

Orrico, C.A., Ravensbergen, T., Pitts, R.A., Bonnin, X., Kaveeva, E., Park, J.S., Rozhansky, V., Senichenkov, I., Watts, C., and de Baar, M.

Subjects
*FUSION reactor divertors, *PLASMA boundary layers, *COMPUTATIONAL electromagnetics, *REAL-time control, *ELECTRIC potential measurement, *HEAT flux
Abstract

Reliable diagnostics that measure the detached state of the ITER divertor plasma will be necessary to control heat flux to the divertor targets during steady state, burning plasma operation. This paper conducts an initial exploration into the feasibility of the divertor shunt diagnostic as a lightweight, robust, and real-time detachment sensor. This diagnostic is a set of shunt lead pairs that measure the voltage drop along the divertor cassette body, from which the plasma scrape-off layer (SOL) current is calculated. Using SOLPS-ITER simulations for control-relevant ITER plasma scenarios, the thermoelectric current magnitude along the SOL is shown to decrease significantly with the onset of partial detachment at the outer divertor target. Electromagnetic modelling of a simplified divertor cassette is used to develop a control-oriented inductance-resistance circuit model, from which SOL currents can be calculated from shunt pair voltage measurements. The sensitivity and frequency-response of the resulting system indicates that the diagnostic will accurately measure SOL thermoelectric currents during ITER operation. These currents will be a good measure of the detached state of the divertor plasma, making the divertor shunt diagnostic a potentially extremely valuable and physically robust sensor for real-time detachment control. [ABSTRACT FROM AUTHOR]

Published
2023
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2. An overview of the STEP divertor design and the simple models driving the plasma exhaust scenario

Author

S.S. Henderson, R.T. Osawa, S.L. Newton, D. Moulton, L. Xiang, R. Futtersack, M. Kryjak, C. Ridgers, J. Karhunen, A. Jarvinen, A. Hudoba, S. Bakes, F. Eriksson, H. Meyer, M. Lord, A. Tarazona, A. Cureton, A. Barth, B. Chuilon, T. Hebrard, S. Wang, Z. Vizvary, D. Vaccaro, F. Perez Smith, J. Farrington, J. Harrison, B. Dudson, and B. Lipschultz

Subjects
STEP, fusion, divertor, exhaust, reduced models, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

This paper presents a comprehensive overview of the preliminary divertor design and plasma exhaust scenario for the reactor-class Spherical Tokamak for Energy Production project. Due to the smaller size of the machine, with a major radius less than half that of most DEMO concepts, the current design features a double-null divertor geometry, comprising tightly baffled extended outer legs and shorter inner legs approaching an X-divertor. Leveraging a significant database of SOLPS-ITER simulations, the exhaust operational space is mapped out, offering valuable insights into the plasma exhaust dynamics. An approach involving the validation of simple, yet robust models capable of accurately predicting key exhaust parameters is detailed, thereby streamlining the design process. The simple models are used to simulate the entire plasma scenario from the plasma current ramp-up, through the burning phase, to the plasma current ramp-down. Notably, the findings suggest that pronounced detachment, with peak heat loads below engineering limits and electron temperatures below 5 eV, is achievable with a divertor neutral pressure between 10 Pa and 15 Pa during the burning phase, and pressures below 5 Pa during the ramp-up to maximise the auxiliary current-drive efficiency. Throughout the scenario, an Ar concentration of ${\approx}3$ % in the scrape-off layer (SOL) is required, in combination with a core radiation fraction of 70% driven by intrinsic emission and extrinsic injection of Xe seeded fuelling pellets. However, significant uncertainties remain regarding key parameters such as the SOL heat flux width, Ar screening, and plasma kinetic effects.

Published
2024
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3. Heat and particle exhaust in high-performance plasmas in Wendelstein 7-X

Author

Yu Gao, Joachim Geiger, Marcin W. Jakubowski, Arun Pandey, Sergey Bozhenkov, Yuhe Feng, Michael Endler, Jürgen Baldzuhn, Valeria Perseo, Thierry Kremeyer, Georg Schlisio, Aleix Puig Sitjes, Matthias Otte, Dirk Naujoks, Maciej Krychowiak, Ralf König, Daihong Zhang, Tamás Szepesi, Gábor Kocsis, Gábor Cseh, Attila Buzás, Fabio Pisano, Alexander Knieps, and the W7-X Team

Subjects
W7-X, high performance, exhaust, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

The paper reports for the first time the heat and particle exhaust at the plasma boundary through various edge diagnostics for the high-performance plasma obtained after pellet injection on Wendelstein 7-X. The plasma density at the edge is found to be reduced by a factor of 2 in the high-performance phase, supporting the previously reported density peaking at the plasma centre. The plasma beta effect on the magnetic topology is reflected by the appearance of the second strike line, which is well understood with simulation. However, during the rapid decay phase of the enhanced confinement, a transient localized heat flow of up to 16 MW m ^−2 is observed at the leading edge of a poorly cooled divertor component, which has not been understood but raises concerns about machine safety.

Published
2024
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4. Data-driven models in fusion exhaust: AI methods and perspectives

Author

S. Wiesen, S. Dasbach, A. Kit, A.E. Jaervinen, A. Gillgren, A. Ho, A. Panera, D. Reiser, M. Brenzke, Y. Poels, E. Westerhof, V. Menkovski, G.F. Derks, and P. Strand

Subjects
exhaust, modeling, machine learning, AI methods, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

A review is given on the highlights of a scatter-shot approach of developing machine-learning methods and artificial neural networks based fast predictors for the application to fusion exhaust. The aim is to enable and facilitate optimized and improved modeling allowing more flexible integration of physics models in the light of extrapolations towards future fusion devices. The project encompasses various research objectives: (a) developments of surrogate model predictors for power & particle exhaust in fusion power plants; (b) assessments of surrogate models for time-dependent phenomena in the plasma-edge; (c) feasibility studies of micro–macro model discovery for plasma-facing components surface morphology & durability; and (d) enhancements of pedestal models & databases through interpolators and generators exploiting uncertainty quantification. Presented results demonstrate useful applications for machine-learning and artificial intelligence in fusion exhaust modeling schemes, enabling an unprecedented combination of both fast and accurate simulation.

Published
2024
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5. Overview of physics results from MAST upgrade towards core-pedestal-exhaust integration

Author

J.R. Harrison, A. Aboutaleb, S. Ahmed, M. Aljunid, S.Y. Allan, H. Anand, Y. Andrew, L.C. Appel, A. Ash, J. Ashton, O. Bachmann, M. Barnes, B. Barrett, D. Baver, D. Beckett, J. Bennett, J. Berkery, M. Bernert, W. Boeglin, C. Bowman, J. Bradley, D. Brida, P.K. Browning, D. Brunetti, P. Bryant, J. Bryant, J. Buchanan, N. Bulmer, A. Carruthers, M. Cecconello, Z.P. Chen, J. Clark, C. Cowley, M. Coy, N. Crocker, G. Cunningham, I. Cziegler, T. Da Assuncao, Y. Damizia, P. Davies, I.E. Day, G.L. Derks, S. Dixon, R. Doyle, M. Dreval, M. Dunne, B.P. Duval, T. Eagles, J. Edmond, H. El-Haroun, S.D. Elmore, Y. Enters, M. Faitsch, F. Federici, N. Fedorczak, F. Felici, A.R. Field, M. Fitzgerald, I. Fitzgerald, R. Fitzpatrick, L. Frassinetti, W. Fuller, D. Gahle, J. Galdon-Quiroga, L. Garzotti, S. Gee, T. Gheorghiu, S. Gibson, K.J. Gibson, C. Giroud, D. Greenhouse, V.H. Hall-Chen, C.J. Ham, R. Harrison, S.S. Henderson, C. Hickling, B. Hnat, L. Howlett, J. Hughes, R. Hussain, K. Imada, P. Jacquet, P. Jepson, B. Kandan, I. Katramados, Y.O. Kazakov, D. King, R. King, A. Kirk, M. Knolker, M. Kochan, L. Kogan, B. Kool, M. Kotschenreuther, M. Lees, A.W. Leonard, G. Liddiard, B. Lipschultz, Y.Q. Liu, B.A. Lomanowski, N. Lonigro, J. Lore, J. Lovell, S. Mahajan, F. Maiden, C. Man-Friel, F. Mansfield, S. Marsden, R. Martin, S. Mazzi, R. McAdams, G. McArdle, K.G. McClements, J. McClenaghan, D. McConville, K. McKay, C. McKnight, P. McKnight, A. McLean, B.F. McMillan, A. McShee, J. Measures, N. Mehay, C.A. Michael, F. Militello, D. Morbey, S. Mordijck, D. Moulton, O. Myatra, A.O. Nelson, M. Nicassio, M.G. O’Mullane, H.J.C. Oliver, P. Ollus, T. Osborne, N. Osborne, E. Parr, B. Parry, B.S. Patel, D. Payne, C. Paz-Soldan, A. Phelps, L. Piron, C. Piron, G. Prechel, M. Price, B. Pritchard, R. Proudfoot, H. Reimerdes, T. Rhodes, P. Richardson, J. Riquezes, J.F. Rivero-Rodriguez, C.M. Roach, M. Robson, K. Ronald, E. Rose, P. Ryan, D. Ryan, S. Saarelma, S. Sabbagh, R. Sarwar, P. Saunders, O. Sauter, R. Scannell, T. Schuett, R. Seath, R. Sharma, P. Shi, B. Sieglin, M. Simmonds, J. Smith, A. Smith, V. A. Soukhanovskii, D. Speirs, G. Staebler, R. Stephen, P. Stevenson, J. Stobbs, M. Stott, C. Stroud, C. Tame, C. Theiler, N. Thomas-Davies, A.J. Thornton, M. Tobin, M. Vallar, R.G.L. Vann, L. Velarde, K. Verhaegh, E. Viezzer, C. Vincent, G. Voss, M. Warr, W. Wehner, S. Wiesen, T.A. Wijkamp, D. Wilkins, T. Williams, T. Wilson, H.R. Wilson, H. Wong, M. Wood, and V. Zamkovska

Subjects
MAST upgrade, exhaust, integrated scenarios, alternative divertors, pedestal, fast ions, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Recent results from MAST Upgrade are presented, emphasising understanding the capabilities of this new device and deepening understanding of key physics issues for the operation of ITER and the design of future fusion power plants. The impact of MHD instabilities on fast ion confinement have been studied, including the first observation of fast ion losses correlated with Compressional and Global Alfvén Eigenmodes. High-performance plasma scenarios have been developed by tailoring the early plasma current ramp phase to avoid internal reconnection events, resulting in a more monotonic q profile with low central shear. The impact of m / n = 3/2, 2/1 and 1/1 modes on thermal plasma confinement and rotation profiles has been quantified, and scenarios optimised to avoid them have transiently reached values of normalised beta approaching 4.2. In pedestal and ELM physics, a maximum pedestal top temperature of ∼350 eV has been achieved, exceeding the value achieved on MAST at similar heating power. Mitigation of type-I ELMs with n = 1 RMPs has been observed. Studies of plasma exhaust have concentrated on comparing conventional and Super-X divertor configurations, while X-point target, X-divertor and snowflake configurations have been developed and studied in parallel. In L-mode discharges, the separatrix density required to detach the outer divertors is approximately a factor 2 lower in the Super-X than the conventional configuration, in agreement with simulations. Detailed analysis of spectroscopy data from studies of the Super-X configuration reveal the importance of including plasma-molecule interactions and D _2 Fulcher band emission to properly quantify the rates of ionisation, plasma-molecule interactions and volumetric recombination processes governing divertor detachment. In H-mode with conventional and Super-X configurations, the outer divertors are attached in the former and detached in the latter with no impact on core or pedestal confinement.

Published
2024
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6. Divertor Tokamak Test facility project: status of design and implementation

Author

Francesco Romanelli, on behalf of DTT Contributors, D. Abate, E. Acampora, D. Agguiaro, R. Agnello, P. Agostinetti, M. Agostini, A. Aimetta, R. Albanese, G. Alberti, M. Albino, E. Alessi, S. Almaviva, M. Alonzo, R. Ambrosino, P. Andreoli, M. Angelone, M. Angelucci, C. Angioni, A. Angrisani Armenio, P. Antonini, D. Aprile, G. Apruzzese, M. Aquilini, G. Aragone, P. Arena, M. Ariola, G. Artaserse, L. Aucone, A. Augieri, F. Auriemma, J. Ayllon Guerola, N. Badodi, B. Baiocchi, L. Balbinot, C. Baldacchini, A. Balestri, T. Barberis, G. Barone, L. Barucca, M. Baruzzo, S. Begozzi, V. Belardi, F. Belli, A. Belpane, F. Beone, S. Bertolami, S. Bianucci, S. Bifaretti, S. Bigioni, W. Bin, P. Boccali, B. Boeswirth, E. Bogazzi, R. Bojoi, S. Bollanti, T. Bolzonella, F. Bombarda, M. Bonan, N. Bonanomi, A. Bonaventura, L. Boncagni, M. Bonesso, D. Bonfiglio, R. Bonifetto, D. Bonomi, D. Borgogno, T. Borzone, S. Botti, E. Boz, F. Braghin, M. Brena, S. Brezinsek, M. Brombin, A. Bruschi, S. Buonocore, P. Buratti, D. Busi, G. Calabrò, M. Caldora, G. Calvo, G. Camera, G. Campana, S. Candela, V. Candela, F. Cani, L. Cantone, F. Capaldo, S. Cappello, M. Caponero, S. Carchella, A. Cardinali, D. Carnevale, L. Carraro, C. Carrelli, V. Casalegno, I. Casiraghi, C. Castaldo, A. Castaldo, G. Castro, A. Carpignano, F. Causa, R. Cavazzana, M. Cavedon, M. Cavenago, M. Cecchini, S. Ceccuzzi, G. Celentano, L. Celona, C. Centioli, G.V. Centomani, S. Cesaroni, A.G. Chiariello, R. Chomicz, C. Cianfarani, F. Cichocki, M. Cinque, A. Cioffi, M. Ciotti, M. Cipriani, S. Ciufo, V. Claps, G. Claps, V. Coccorese, D. Coccorese, A. Colangeli, T. Coltella, F. Consoli, F. Cordella, D. Corradini, O. Costa, F. Crea, A. Cremona, F. Crescenzi, F. Crisanti, G. Cristofari, G. Croci, A. Cucchiaro, D. D’Ambrosio, M. Dal Molin, M. Dalla Palma, F. Danè, C. Day, M. De Angeli, V. De Leo, R. De Luca, E. De Marchi, G. De Marzi, G. De Masi, E. De Nardi, C. De Piccoli, G. De Sano, M. De Santis, G. De Tommasi, A. Del Nevo, A. Delfino, A. Della Corte, P. Deodati, S. Desiderati, E. Di Ferdinando, M.G. Di Florio, G. Di Gironimo, L.E. Di Grazia, V. Di Marzo, F. Di Paolo, E. Di Pietro, M. Di Pietrantonio, M. Di Prinzio, A. Di Silvestre, A. Di Zenobio, R. Dima, A. Domenichelli, A. Doria, G. Dose, S. Dubbioso, S. Dulla, I. Duran, M. Eboli, M. Elitropi, E. Emanuelli, B. Esposito, P. Ettorre, C. Fabbri, F. Fabbri, M. Fadone, M.M. Faggiano, F. Falcioni, M.V. Falessi, F. Fanale, P. Fanelli, A. Fassina, M. Favaretto, G. Favero, M. Ferraris, F. Ferrazza, C. Ferretti, A. Ferro, N. Ferron, C. Fiamozzi Zignani, L. Figini, F. Filippi, M. Filippini, A. Fimiani, M. Fincato, F. Fiorenza, D. Fiorucci, D. Flammini, F. Flora, N. Fonnesu, P. Franz, L. Frassinetti, A. Frattolillo, R. Freda, R. Fresa, A. Frescura, P. Frosi, M. Fulici, M. Furno Palumbo, V. Fusco, P. Fusco, L. Gabellier, P. Gaetani, E. Gaio, E. Gajetti, A. Galatà, J. Galdon Quiroga, D.L. Galindo Huertas, S. Gammino, G. Gandolfo, S. Garavaglia, J. Garcia Lopez, M. Garcia Muñoz, P. Gaudio, M. Gelfusa, G. Gervasini, L. Giannini, M. Giarrusso, C. Gil, F. Giorgetti, E. Giovannozzi, G. Giruzzi, L. Giudicotti, M. Gobbin, G. Gorini, G. Granucci, D. Grasso, T. Grasso, S. Grazioso, H. Greuner, G. Griva, G. Grosso, S. Guerini, J.P. Gunn, V. Hauer, J. Hidalgo Salaverri, M. Hoppe, M. Houry, M. Hoelzl, A. Iaboni, M. Iafrati, A. Iaiunese, V. Imbriani, D. Indrigo, P. Innocente, F. Koechl, B. Končar, A. Kryzhanovskyy, L. Laguardia, D.A. Lampasi, C. Lanchi, F. Lanzotti, A. Lanzotti, M. Laquaniti, F. Leone, J. Li, M. Libè, F. Lisanti, D. Liuzza, F. Locati, R. Lombroni, R. Lorenzini, P. Lorusso, L. Lotto, J. Loureiro, F. Lucca, T. Luda Di Cortemiglia, P. Maccari, G. Maddaluno, S. Magagnino, G. Manca, A. Mancini, P. Mandalà, B. Mandolesi, F. Mandrile, G. Manduchi, S. Manfrin, M. Manganelli, P. Mantica, G. Marchiori, N. Marconato, G. Marelli, A. Mariani, A. Marin, R. Marinari, M. Marinelli, F. Marino, P. Marino, D. Marocco, R. Marsilio, E. Martelli, P. Martin, F. Martinelli, G. Martini, R. Martone, A. Marucci, D. Marzullo, V. Masala, D. Mascali, F. Mascari, A. Masi, N. Massanova, S. Mastrostefano, M. Mattei, G. Mauro, S. Mauro, C. Meineri, L. Melaragni, A. Mele, P. Meller, S. Meloni, I. Menicucci, G. Messina, L. Mezi, G. Miccichè, M. Micheletti, S. Migliori, D. Milanesio, F. Milazzo, R. Milazzo, P. Minelli, S. Minucci, F. Mirizzi, M. Missirlian, D. Monarca, C. Monti, M. Mori, A. Moriani, L. Morici, A. Moro, F. Moro, P. Mosetti, R. Mozzillo, A. Murari, A. Muraro, D. Murra, P. Muscente, S. Musumeci, L. Muzzi, G.F. Nallo, F. Napoli, E. Nardon, E. Naselli, R. Neu, M. Nocente, M. Notazio, S. Nowak, E. Ocello, A. Oliva, V. Orsetti, A. Orsini, F.P. Orsitto, M. Ortino, M. Ottavi, G. Paccagnella, D. Pacella, I. Pagani, N. Paganucci, A. Pagliaro, V. Palazzolo, M. Palermo, S. Palomba, F. Panza, D. Paoletti, M. Parisi, R. Pasqualotto, S. Passarello, M. Passoni, T. Patton, L. Pelliccia, A. Peloso, A. Pepato, E. Perelli, A. Perencin, S. Peruzzo, A. Pesenti, N. Pedroni, P. Petrolini, V. Piergotti, A. Pidatella, L. Pigatto, M. Pillon, T. Pinna, S. Pipolo, S. Piras, C. Piron, L. Piron, A. Pironti, M. Pistilli, D. Placido, A. Pizzuto, P. Platania, A. Polimadei, F. Pollastrone, G.M. Polli, N. Pomaro, F. Pompili, C. Ponti, F. Porcelli, V. Prandelli, A. Previti, A. Princiotta, G. Pucino, F. Quaglia, A. Quercia, F. Raffaelli, G. Ramogida, G. Ranieri, B. Raspante, D. Ravarotto, G.L. Ravera, A. Reale, P. Rebesan, M. Recchia, D. Regine, F. Renno, B. Riccardi, D. Ricci, D. Rigamonti, M. Ripani, N. Rispoli, S. Roccella, G. Rocchi, H. Roche, M. Romanato, F. Romanelli, G. Romanelli, R. Romaniello, A. Romano, M. Romano, R. Romano, R. Rossi, G. Rubinacci, G. Rubino, S. Rubino, J. Rueda Rueda, A. Rufoloni, C. Salvia, P. Salvini, M. Scarpari, A. Salvitti, L. Salvò, S. Sandri, F. Santoro, A. Satriano, L. Savoldi, C. Scardino, G. Schettini, S. Schmuck, J. Scionti, M. Scisciò, M. Scungio, K. Sedlak, L. Senni, G. Sias, A. Sibio, A. Simonetto, L. Singh, A. Sirignano, C. Sozzi, I. Spada, S. Spagnolo, L. Spinicci, G. Spizzo, M. Spolaore, C. Stefanini, H. Strobel, F. Subba, F. Taccogna, B. Taheri, C. Tantos, A. Tarallo, M. Tarantino, G. Tardini, M. Tardocchi, P. Tarfila, A. Tenaglia, C. Terlizzi, D. Terranova, D. Testa, E. Testa, R. Testoni, V. Toigo, G. Torrisi, A. Trotta, G. Trovato, E. Tsitrone, A. Tuccillo, O. Tudisco, M. Turcato, S. Turtù, A. Uccello, M. Ugoletti, O. Uras, M. Uras, M. Utili, V. Vaccaro, F. Valentini, L. Valletti, M. Valisa, D. Van Eester, D. Vanzan, E. Vassallo, G. Vecchi, M. Vellucci, I. Venneri, G. Ventura, M. Veranda, L. Verdini, C. Verona, G. Verona Rinati, F. Veronese, N. Vianello, F. Viganò, O. Villano, R. Villari, F. Villone, P. Vincenzi, V. Vitale, F. Vivio, G. Vlad, M. Wischmeier, H.S. Wu, I. Wyss, R. Zanino, B. Zaniol, F. Zanon, A. Zappatore, G. Zavarise, P. Zito, A. Zoppoli, M. Zucchetti, M. Zuin, and P. Zumbolo

Subjects
divertor, exhaust, plasma scenarios, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

An overview is presented of the progress since 2021 in the construction and scientific programme preparation of the Divertor Tokamak Test (DTT) facility. Licensing for building construction has been granted at the end of 2021. Licensing for Cat. A radiologic source has been also granted in 2022. The construction of the toroidal field magnet system is progressing. The prototype of the 170 GHz gyrotron has been produced and it is now under test on the FALCON facility. The design of the vacuum vessel, the poloidal field coils and the civil infrastructures has been completed. The shape of the first DTT divertor has been agreed with EUROfusion to test different plasma and exhaust scenarios: single null, double null, X-divertor and negative triangularity plasmas. A detailed research plan is being elaborated with the involvement of the EUROfusion laboratories.

Published
2024
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7. REQUIREMENTS FOR COLLISION DATA ON THE SPECIES HELIUM, BERYLLIUM AND BORON IN MAGNETIC CONFINEMENT FUSION

Subjects
PLASMA, JT-60, JET, TOKAMAK, BEAM, EXCHANGE RECOMBINATION SPECTROSCOPY, TEXTOR, TRANSPORT, EXHAUST
Abstract

Requirements for collision data on helium, beryllium and boron are reviewed in the light of the directions of present and planned tokamak fusion experiments. The occurrence of the atoms and ions of these species and their roles in plasma behaviour and diagnostic measurements are described. Special emphasis is placed on alpha particle detection in reacting plasmas and on beryllium and boron in divertor configuration machines. The atomic reactions required to exploit the species in models and diagnostic analysis are gathered together and their relative importance indicated. The paper is an introduction to the detailed studies of collision cross-sections presented in the other contributions to this volume.

Published
1992

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