THIS is a volume honoring Dean L. M. K. Boeiter of UCLA on the occasion of his sixty-fifth birthday, and it-consists of thirty-four technical papers authored by his students, colleagues, and associates. In view of the number of papers involved, it is obvious that, no attempt toward individual review can be made here. Basically, the papers are divided into four categories: (a) Heat-mass transfer and thermodynamics; (6) Materials, mechanics, and design; (c) Engineering education; and (d) City planning.

A symbolic notation devised by Reuleaux to describe mechanisms did not recognize the necessary number of variables needed for complete description. A reconsideration of the problem leads to a symbolic notation which permits the complete description of the kinematic properties of all lower-pair mechanisms by means of equations. The symbolic notation also yields a method for studying lower-pair mechanisms by means of matrix algebra; two examples of application to space mechanisms are given.

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A theory of magnetospheric VLF emissions must account for the following features: (a) the triggering of monochromatic emissions by signals of sufficient strength and duration, while the background noise and weak short signals are not amplified, and (b) the occurrence of frequency changes after the emissions have reached a sufficiently large amplitude. A nonlinear mechanism exhibiting these features, with fixed and varying frequencies, is examined analytically and by computer simulation techniques. This mechanism depends on a simultaneous propagation and amplification of wave packets along geomagnetic lines to maintain the nonuniformity ratio R ∝ ▽B0/Bw in the regime |R| ≈ 0.5, corresponding to maximum amplitication. (B0 is the geomagnetic field and Bw is the wave magnetic field.) For a constant frequency, this condition yields triggering thresholds which are related to the properties of the magnetosphere. For a varying frequency ω(t), it yields the condition ∂ω/∂t ∝ ωt² for the large‐amplitude portion of the risers, where ωt ∝ Bw1/2 denotes the trapping frequency of the wave.

Particle simulations of the expansion of a collisionless plasma into vacuum are presented. The cases of a single-electron-temperature plasma and of a two-electron-temperature plasma are considered. The results confirm the existence of an ion front and verify the general features of self-similar solutions behind this front. A cold electron front is clearly observed in the two-electron-temperatures case. The computations also show that for a finite electron-to-ion mass ratio, me/mi, the electron thermal velocity in the expansion region is not constant, but decreases approximately linearly with ξ=x/t, where x is distance and t is time. A self-similar solution, derived from the relation Ten1−γe=const, where Te is the electron temperature, ne is the electron density, and γ is a constant (instead of the isothermal assumption made in earlier theories), yields a linearly decreasing ion acoustic speed, c≃c0−(γ−1) ξ/2, and comparison with computer simulation results show that the constant γ−1 is proportional to (Zme/mi)1/2, where Z is the ion charge number.