Hornung, Hans G.

Combined from CaltechAUTHORS

• Schwartz, Tal and Finch, Peter M., et el. (2023) Laser Absorption Sensor Targeting Potassium for Hypersonic Velocity, Temperature, and Enthalpy Measurements; AIAA Journal; 10.2514/1.j062620
• Finch, Peter M. and Girard, Julian J., et el. (2023) Measurements of T5 Shock Tunnel Freestream Temperature, Velocity, and Composition; AIAA Journal; Vol. 61; No. 4; 1555-1578; 10.2514/1.j062383
• Martinez Schramm, Jan and Hannemann, Klaus, et el. (2023) Hypersonic flow over spherically blunted cone capsules for atmospheric entry. Part 2. Vibrational non-equilibrium effects; Journal of Fluid Mechanics; Vol. 954; Art. No. A32; 10.1017/jfm.2022.1014
• Finch, Peter M. and Schwartz, Tal, et el. (2023) Near-Body Measurements in Hypersonic Wedge Flows in the T5 Reflected Shock Tunnel by Tunable Diode Laser Absorption Spectroscopy; ISBN 978-1-62410-699-6; AIAA SCITECH 2023 Forum; Art. No. 2023-2518; 10.2514/6.2023-2518
• Hornung, H. G. and Gollan, R. J., et el. (2022) Computational analysis of experiments on shock detachment in hypersonic flow of nitrogen and carbon dioxide over a wedge; Journal of Fluid Mechanics; Vol. 951; Art. No. A6; 10.1017/jfm.2022.838
• Yu, Wesley M. and Austin, Joanna M., et el. (2022) Freestream Static Pressure Measurements in the T5 Reflected Shock Tunnel; 10.2514/6.2022-1658
• Finch, Peter M. and Schwartz, Tal, et el. (2022) Near-Body Measurements in Hypersonic Cylinder Flows in the T5 Reflected Shock Tunnel by Tunable Diode Laser Absorption Spectroscopy; ISBN 978-1-62410-631-6; AIAA Scitech 2022 Forum; Art. No. 2022-1705; 10.2514/6.2022-1705
• Girard, Julian J. and Finch, Peter M., et el. (2021) Measurements of Reflected Shock Tunnel Freestream Nitric Oxide Temperatures and Partial Pressure; AIAA Journal; Vol. 59; No. 12; 5266-5275; 10.2514/1.j060596
• Girard, Julian and Finch, Peter M., et el. (2021) Characterization of the T5 Reflected Shock Tunnel Freestream Temperature, Velocity, and Composition using Laser Absorption Spectroscopy; ISBN 978-1-62410-611-8; AIAA Propulsion and Energy 2021 Forum; Art. No. 2021-3525; 10.2514/6.2021-3525
• Schwartz, Tal and Girard, Julian, et el. (2021) Characterization of the Caltech Hypervelocity Expansion Tube via Tunable Diode Laser Absorption Spectroscopy; ISBN 978-1-62410-611-8; AIAA Propulsion and Energy 2021 Forum; Art. No. 2021-3524; 10.2514/6.2021-3524
• Hornung, H. G. and Gollan, R. J., et el. (2021) Unsteadiness boundaries in supersonic flow over double cones; Journal of Fluid Mechanics; Vol. 916; Art. No. A5; 10.1017/jfm.2021.203
• Hornung, H. G. (2021) Shock detachment and drag in hypersonic flow over wedges and circular cylinders; Journal of Fluid Mechanics; Vol. 915; Art. No. A100; 10.1017/jfm.2021.187
• Urie, David and Hornung, Hans G., et el. (2020) Course AE107 case studies in engineering: the SR-71 Blackbird
• Finch, Peter M. and Girard, Julian, et el. (2020) Measurements of Time-Resolved Air Freestream Nitric Oxide Rotational, Vibrational Temperature and Concentration in the T5 Reflected Shock Tunnel; ISBN 978-1-62410-602-6; AIAA Propulsion and Energy 2020 Forum; Art. No. 2020-3714; 10.2514/6.2020-3714
• Hornung, H. G. (2019) Effect of Conical Free Stream on Shock Stand-Off Distance; AIAA Journal; Vol. 57; No. 9; 4115-4116; 10.2514/1.J058385
• Hornung, H. G. and Martinez Schramm, Jan, et el. (2019) Hypersonic flow over spherically blunted cone capsules for atmospheric entry. Part 1. The sharp cone and the sphere; Journal of Fluid Mechanics; Vol. 871; 1097-1116; 10.1017/jfm.2019.342
• Hornung, H. G. (2016) A model problem for a supersonic gas jet from a moon; Journal of Fluid Mechanics; Vol. 795; 950-971; 10.1017/jfm.2016.184
• Schmidt, B. E. and Bitter, N. P., et el. (2016) Injection into Supersonic Boundary Layers; AIAA Journal; Vol. 54; No. 1; 161-173; 10.2514/1.J054123
• Hannemann, Klaus and Itoh, Katsuhiro, et el. (2015) Free Piston Shock Tunnels HEG, HIEST, T4 and T5; ISBN 978-3-319-23744-2; Experimental Methods of Shock Wave Research; 181-264; 10.1007/978-3-319-23745-9_7
• Parziale, N. J. and Shepherd, J. E., et el. (2015) Observations of hypervelocity boundary-layer instability; Journal of Fluid Mechanics; Vol. 781; 87-112; 10.1017/jfm.2015.489
• Parziale, N. J. and Schmidt, B. E., et el. (2015) Pulsed Laser Diode for Use as a Light Source for Short-Exposure, High-Frame-Rate Flow Visualization; ISBN 9781624103438; AIAA SciTech : 53rd AIAA Aerospace Sciences Meeting; Art. No. 2015-0530; 10.2514/6.2015-0530
• Parziale, N. J. and Shepherd, J. E., et el. (2015) Geometric Acoustics in High-Speed Boundary Layers; ISBN 978-3-319-16834-0; 29th International Symposium on Shock Waves; 711-716; 10.1007/978-3-319-16835-7_114
• Hornung, Hans G. (2014) Mach Reflection in Steady Flow. I. Mikhail Ivanov's Contributions, II. Caltech Stability Experiments; ISBN 978-0-7354-1265-1; Proceedings of the 29th International Symposium on Rarefied Gas Dynamics; 1384-1393; 10.1063/1.4902753
• Candler, G. V. and Dimotakis, P. E., et el. (2014) Interaction of Chemistry, Turbulence, and Shock Waves in Hypervelocity Flow; 10.7907/wbg4-ra84
• Hornung, H. and Sturtevant, B. (2014) Challenges for high-enthalpy gasdynamics research during the 1990's: Plans for the GALCIT T5 Laboratory; 10.7907/59j9-jp14
• Schmidt, B. E. and Bitter, N. P., et el. (2014) Experimental Investigation of Gas Injection into the Boundary Layer on a Slender Body in Supersonic Flow; ISBN 978-1-62410-293-6; 7th AIAA Theoretical Fluid Mechanics Conference; Art. No. 2014-2496; 10.2514/6.2014-2496
• Parziale, N. J. and Shepherd, J. E., et el. (2014) Free-stream density perturbations in a reflected-shock tunnel; Experiments in Fluids; Vol. 55; No. 2; Art. No. 1665; 10.1007/s00348-014-1665-0
• Parziale, N. J. and Rabinovitch, J., et el. (2013) Proposed Vertical Expansion Tunnel; AIAA Journal; Vol. 51; No. 12; 2792-2799; 10.2514/1.J052389
• Parziale, N. J. and Shepherd, J. E., et el. (2013) Differential Interferometric Measurement of Instability in a Hypervelocity Boundary Layer; AIAA Journal; Vol. 51; No. 3; 750-754; 10.2514/1.J052013
• Parziale, N. J. and Shepherd, J. E., et el. (2013) Differential Interferometric Measurement of Instability at Two Points in a Hypervelocity Boundary Layer; ISBN 9781624101816; 51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition; Art. No. 2013-0521; 10.2514/6.2013-521
• Parziale, N. J. and Shepherd, J. E., et el. (2012) Reflected Shock Tunnel Noise Measurement by Focused Differential Interferometry; ISBN 9781600869334; 42nd AIAA Fluid Dynamics Conference and Exhibit; Art. No. 2012-3261; 10.2514/6.2012-3261
• Parziale, N. J. and Rabinovitch, J., et el. (2012) A Proposed Vertical Expansion Tunnel; ISBN 9781600869334; 42nd AIAA Fluid Dynamics Conference and Exhibit; Art. No. 2012-3263; 10.2514/6.2012-3263
• Marineau, Eric and Hornung, Hans (2012) Heat Flux Calibration of T5 Hypervelocity Shock Tunnel Conical Nozzle in Air; ISBN 978-1-60086-973-0; 47th AIAA Aerospace Sciences Meeting including The New Horizons Forum and Aerospace Exposition; Art. No. 2009-1158; 10.2514/6.2009-1158
• Hornung, Hans G. and Schramm, Jan Martinez, et el. (2012) Sonic Line and Stand-Off Distance on Re-entry Capsule Shapes; ISBN 978-3-642-25684-4; 28th International Symposium on Shock Waves; 605-611; 10.1007/978-3-642-25685-1_92
• Parziale, N. J. and Jewell, J. S., et el. (2012) Shock Tunnel Noise Measurement with Resonantly Enhanced Focused Schlieren Deflectometry; ISBN 978-3-642-25687-5; 28th International Symposium on Shock Waves; 747-752; 10.1007/978-3-642-25688-2_113
• Karl, Sebastian and Hannemann, Klaus, et el. (2012) Bluntness Effects in Hypersonic Flow over Slender Cones and Wedges; ISBN 978-3-642-25684-4; 28th International Symposium on Shock Waves; 691-696; 10.1007/978-3-642-25685-1_105
• Hornung, H. G. (2010) Deriving Features of Reacting Hypersonic Flow from Gradients at a Curved Shock; AIAA Journal; Vol. 48; No. 2; 287-296; 10.2514/1.39993
• Sanderson, S. R. and Austin, J. M., et el. (2010) Reactant jetting in unstable detonation; Progress in Aerospace Sciences; Vol. 46; No. 2-3; 116-131; 10.1016/j.paerosci.2009.11.002
• Wen, Chihyung and Hornung, Hans (2010) Nonequilibrium recombination after a curved shock wave; Progress in Aerospace Sciences; Vol. 46; No. 2-3; 132-139; 10.1016/j.paerosci.2009.11.001
• Marineau, Eric C. and Hornung, Hans G. (2010) Study of Bow-Shock Wave Unsteadiness in Hypervelocity Flow from Reservoir Fluctuations; ISBN 9781600869594; 48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition; Art. No. 2010-382; 10.2514/6.2010-382
• Marineau, Eric C. and Laurence, Stuart J., et el. (2010) Apollo-Shaped Capsule Boundary Layer Transition at High-Enthalpy in T5; ISBN 9781600869594; 48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition; Art. No. 2010-446; 10.2514/6.2010-446
• Wagnild, Ross M. and Candler, Graham V., et el. (2010) Carbon Dioxide Injection for Hypervelocity Boundary Layer Stability; ISBN 978-1-60086-959-4; 48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition; Art. No. 2010-1244; 10.2514/6.2010-1244
• Leyva, Ivett A. and Jewell, Joseph S., et el. (2009) On the impact of injection schemes on transition in hypersonic boundary layers; ISBN 9781600869686; 16th AIAA/DLR/DGLR International Space Planes and Hypersonic Systems and Technologies Conference; Art. No. 2009-7204; 10.2514/6.2009-7204
• Hornung, H. G. and Roshko, A. (2009) In memoriam Prof. Hans W. Liepmann (1914–2009); Shock Waves; Vol. 19; No. 5; 447-448; 10.1007/s00193-009-0223-9
• Marineau, Eric C. and Hornung, Hans G. (2009) High-Enthalpy Nonequilibrium Nozzle Flow of Air: Experiments and Computations; ISBN 9781600869716; 39th AIAA Fluid Dynamics Conference; Art. No. 2009-4216; 10.2514/6.2009-4216
• Sanderson, Simon R. and Austin, Joanna M., et el. (2009) Reactant Jetting in Unstable Detonation; ISBN 1-56347-975-3; 39th AIAA Fluid Mechanics Conference; Art. No. -2009-4325; 10.2514/6.2009-4325
• Hornung, H. G. (2009) Relaxation effects in hypervelocity flow: selected contributions from the T5 Lab; ISBN 9783540851677; Shock Waves; 3-10; 10.1007/978-3-540-85168-4_1
• Laurence, Stuart J. and Hornung, H. G. (2009) Image-based force and moment measurement in hypersonic facilities; Experiments in Fluids; Vol. 46; No. 2; 10.1007/s00348-008-0565-6
• Marineau, Eric C. and Hornung, Hans G. (2009) Modeling and Calibration of Fast-Response Coaxial Heat Flux Gages; ISBN 978-1-60086-973-0; 47th AIAA Aerospace Sciences Meeting including The New Horizons Forum and Aerospace Exposition; Art. No. 2009-737; 10.2514/6.2009-737
• Leyva, Ivett A. and Laurence, Stuart, et el. (2009) Transition Delay in Hypervelocity Boundary Layers by Means of CO₂/Acoustic Instability Interactions; ISBN 978-1-60086-973-0; 47th AIAA Aerospace Sciences Meeting including The New Horizons Forum and Aerospace Exposition; Art. No. 2009-1287; 10.2514/6.2009-1287
• Mouton, C. A. and Hornung, H. G. (2009) Experimental investigation of tripping between regular and Mach reflection in the dual-solution domain; ISBN 9783540851806; Shock Waves; 1413-1418; 10.1007/978-3-540-85181-3_100
• Laurence, S. J. and Deiterding, R., et el. (2009) Tandem spheres in hypersonic flow; ISBN 9783540851677; Shock Waves; 713-718; 10.1007/978-3-540-85168-4_115
• Mouton, Christopher and Hornung, Hans G. (2008) Experiments on the mechanism of inducing transition between regular and Mach reflection; Physics of Fluids; Vol. 20; No. 12; Art. No. 126103; 10.1063/1.3042261
• Hornung, H. G. and Pullin, D. I., et el. (2008) On the question of universality of imploding shock waves; Acta Mechanica; Vol. 201; No. 1-4; 31-35; 10.1007/s00707-008-0070-2
• Hornung, H. G. (2008) Deriving Features of Reacting Hypersonic Flows from Gradients at Curved Shocks; ISBN 978-1-60086-995-2; 5th AIAA Theoretical Fluid Mechanics Conference; Art. No. 2008-4340; 10.2514/6.2008-4340
• Hornung, H. G. and Mouton, C. A. (2008) Some More on Transition Between Regular and Mach Reflection of Shock Waves in Steady Flow (Invited); ISBN 978-1-60086-989-1; 38th Fluid Dynamics Conference and Exhibit; Art. No. 2008-3845; 10.2514/6.2008-3845
• Laurence, Stuart J. and Deiterding, R., et el. (2007) Proximal bodies in hypersonic flow; Journal of Fluid Mechanics; Vol. 590; 209-237; 10.1017/S0022112007007987
• Mouton, Christopher A. and Hornung, Hans G. (2007) Mach Stem Height and Growth Rate Predictions; AIAA Journal; Vol. 45; No. 8; 1977-1987; 10.2514/1.27460
• Wright, Michael J. and Olejniczak, Joe, et el. (2006) Modeling of Shock Tunnel Aeroheating Data on the Mars Science Laboratory Aeroshell; Journal of Thermophysics and Heat Transfer; Vol. 20; No. 4; 641-651; 10.2514/1.19896
• Ponchaut, N. F. and Hornung, H. G., et el. (2006) On imploding cylindrical and spherical shock waves in a perfect gas; Journal of Fluid Mechanics; Vol. 560; 130-122; 10.1017/S0022112006000590
• Hornung, Hans G. (2006) Hypersonic Real-Gas Effects on Transition; ISBN 978-1-4020-4149-5; IUTAM Symposium on One Hundred Years of Boundary Layer Research; 335-344; 10.1007/978-1-4020-4150-1_32
• Ponchaut, N. F. and Mouton, C. A., et el. (2005) 3D Particle Tracking Velocimetry Method: Advances and Error Analysis; 10.7907/qnad-cw63
• Shepherd, J. E. and Hornung, H. G. (2005) Blast Waves and Explosions Sound generation by explosive decompression of an airplane; ISBN 978-3-540-22497-6; Shock Waves; 973-978; 10.1007/978-3-540-27009-6_148
• Sanderson, S. R. and Hornung, H. G., et el. (2004) The influence of non-equilibrium dissociation on the flow produced by shock impingement on a blunt body; Journal of Fluid Mechanics; Vol. 516; 1-37; 10.1017/S0022112004000357
• Kumar, Sanjay and Hornung, H. G., et el. (2003) Growth of shocked gaseous interfaces in a conical geometry; Physics of Fluids; Vol. 15; No. 10; 3194-3208; 10.1063/1.1608011
• Fujii, Keisuke and Hornung, Hans G. (2003) Experimental Investigation of High-Enthalpy Effects on Attachment-Line Boundary-Layer Transition; AIAA Journal; Vol. 41; No. 7; 1282-1291
• Sanderson, S. R. and Hornung, H. G., et el. (2003) Aspects of planar, oblique and interacting shock waves in an ideal dissociating gas; Physics of Fluids; Vol. 15; No. 6; 1638-1649; 10.1063/1.1572162
• Lemieux, P. and Hornung, H. (2002) Development and application of streakline visualization in hypervelocity flows; Experiments in Fluids; Vol. 33; No. 1; 188-195; 10.1007/s00348-002-0433-8
• Hornung, H. G. (2002) Hypersonic flow over bodies in tandem; Shock Waves; Vol. 11; No. 6; 441-445; 10.1007/s001930200131
• Rasheed, A. and Hornung, H. G., et el. (2002) Experiments on Passive Hypervelocity Boundary-Layer Control Using an Ultrasonically Absorptive Surface; AIAA Journal; Vol. 40; No. 3; 481-489
• Hornung, H. G. and Schwendeman, D. W. (2001) Oblique shock reflection from an axis of symmetry: shock dynamics and relation to the Guderley singularity; Journal of Fluid Mechanics; Vol. 438; 231-245; 10.1017/S0022112001004360
• Fedorov, Alexander V. and Malmuth, Norman D., et el. (2001) Stabilization of Hypersonic Boundary Layers by Porous Coatings; AIAA Journal; Vol. 39; No. 4; 605-610
• Fujii, Keisuke and Hornung, Hans G. (2001) A Procedure to Estimate Absorption Rate of Sound Propagating Through High Temperature Gas; 10.7907/qt5w-pv02
• Schlamp, Stefan and Hornung, Hans G., et el. (2000) Accuracy and uncertainty of single-shot, nonresonant laser-induced thermal acoustics; Applied Optics; Vol. 39; No. 30; 5477-5481
• Schlamp, Stefan and Hornung, Hans G., et el. (2000) Neural network data analysis for laser-induced thermal acoustics; Measurement Science and Technology; Vol. 11; No. 6; 784-794; 10.1088/0957-0233/11/6/323
• Hornung, H. G. (2000) Oblique shock reflection from an axis of symmetry; Journal of Fluid Mechanics; Vol. 409; 1-12; 10.1017/S0022112099007831
• Leyva, I. A. and Hornung, H. G. (2000) Shock Detachment Process in Hypervelocity Flow over a Cone; ISBN 085432707X; Proceedings of the 22nd International Symposium on Shock Waves; 1607-1612; 10.7907/GRNB-AA64
• Schlamp, Stefan and Cummings, Eric B., et el. (1999) Beam Misalignments and Fluid Velocities in Laser-Induced Thermal Acoustics; Applied Optics; Vol. 38; No. 27; 5724-5733
• Cummings, Eric B. and Hornung, Hans G., et el. (1995) Measurement of gas-phase sound speedand thermal diffusivity over a broad pressure range using laser-induced thermal acoustics; Optics Letters; Vol. 20; No. 14; 1577-1579
• Cummings, E. B. and Leyva, I. A., et el. (1995) Laser-induced thermal acoustics (LITA) signals from finite beams; Applied Optics; Vol. 34; No. 15; 3290-3302
• Hornung, Hans G. and Willert, Christian, et el. (1995) The flow field downstream of a hydraulic jump; Journal of Fluid Mechanics; Vol. 287; 299-316; 10.1017/S0022112095000966
• Wen, Chihyung and Hornung, Hans (1995) Experiments on Hypervelocity Dissociating Flow over Spheres; ISBN 978-3-642-78834-5; Shock Waves @ Marseille II - Physico-Chemical Processes and Nonequilibrium Flow; 223-228; 10.1007/978-3-642-78832-1_37
• Bélanger, J. and Hornung, H. (1995) Transverse Jet Mixing and Combustion Experiments in the Hypersonic Shock Tunnel T5 at GALCIT; ISBN 978-3-642-78831-4; Shock Waves @ Marseille I - Hypersonics, Shock Tube & Shock Tunnel Flow; 157-162; 10.1007/978-3-642-78829-1_25
• Germain, P. and Hornung, H. (1995) The Boundary Layer on a Sharp Cone in High-Enthalpy Flow; ISBN 978-3-642-78831-4; Shock Waves @ Marseille I - Hypersonics, Shock Tube & Shock Tunnel Flow; 63-68; 10.1007/978-3-642-78829-1_9
• Hornung, H. G. and Germain, P. (1995) An Exploratory Study of Transition on a Slender Cone in Hypervelocity Flow; ISBN 9783642797675; Laminar-Turbulent Transition; 155-162; 10.1007/978-3-642-79765-1_18
• Hornung, H. G. and Shepherd, J. E., et el. (1994) 20th International Symposium on Shock Waves; Shock Waves; Vol. 4; No. 3; 167-167; 10.1007/bf01417433
• Hornung, H. and Wen, C., et el. (1994) Hypervelocity flow over spheres; ISBN 978-3-211-82495-5; Fluid- and Gasdynamics; 163-170; 10.1007/978-3-7091-9310-5_19
• Hornung, H. and Sturtevant, B., et el. (1992) Performance data of the new free-piston shock tunnel T5 at GALCIT; ISBN 978-3-642-77650-2; Shock Waves; 603-610; 10.1007/978-3-642-77648-9_95
• Hornung, H. G. (1989) Concluding Remarks; ISBN 9783642835865; Symposium Transsonicum III; 501-504; 10.1007/978-3-642-83584-1_40
• Hornung, H. G. (1988) 28th Lanchester Memorial Lecture — Experimental real-gas hypersonics; Aeronautical Journal; Vol. 92; No. 920; 379-389; 10.1017/S0001924000016511
• Hornung, Hans (1986) Regular and Mach reflection of shock waves; Annual Review of Fluid Mechanics; Vol. 18; 33-58; 10.1146/annurev.fl.18.010186.000341
• Hornung, Hans (1985) The effect of viscosity on the mach stem length in unsteady strong shock reflection; ISBN 978-3-540-15989-6; Flow of Real Fluids; 82-91; 10.1007/3-540-15989-4_73
• Hornung, H. G. and Oertel, H., et el. (1979) Transition to Mach reflexion of shock waves in steady and pseudosteady flow with and without relaxation; Journal of Fluid Mechanics; Vol. 90; No. 3; 541-560; 10.1017/S002211207900238X
• Hornung, Hans and Killen, Peter (1977) Laboratory study of a stationary oblique plunging breaker for surfboard testing; ISBN 978-3-540-08253-8; Waves on Water of Variable Depth; 121-128; 10.1007/3540082530_143
• Hornung, H. G. (1976) Non-equilibrium ideal-gas dissociation after a curved shock wave; Journal of Fluid Mechanics; Vol. 74; No. 1; 143-159; 10.1017/S0022112076001730
• Kewley, D. J. and Hornung, H. G. (1974) Non-equilibrium dissociating nitrogen flow over a wedge; Journal of Fluid Mechanics; Vol. 64; No. 4; 725-736; 10.1017/S002211207400187X
• Hornung, H. G. (1972) Non-equilibrium dissociating nitrogen flow over spheres and circular cylinders; Journal of Fluid Mechanics; Vol. 53; No. 1; 149-176; 10.1017/S0022112072000084
• Hornung, H. G. (1972) Non-equilibrium dissociating nitrogen flow over spheres and circular cylinders; Journal of Fluid Mechanics; Vol. 53; No. 1; 149-176; 10.1017/S0022112072000084
• Hornung, H. G. (1969) Some aspects of hypersonic flow over power law bodies; Journal of Fluid Mechanics; Vol. 39; No. 1; 143-162; 10.1017/S0022112069002084