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Empirical evidence is presented to show that the geometry of tool wear, and the presence of built-up-edge, is strongly controlled by the chip curl. Evidence is also given which shows that some free-machining additives affect only the cutting temperature while others may affect the basic wear mechanism. Two simple theories are presented for calculating the rate of tool wear based on diffusion of tool material into the workpiece. While not conclusive, the results show remarkable agreement between predicted and measured wear based on a model wherein tool atoms jump into excess vacancies created in the chip by the plastic deformation of friction.

In this paper, the mechanism of chip curl is studied, and the importance of chip curl on such practical consequences as tool life and surface finish is noted. A new set of ideas concerning the cause-effect relationship between chip-curl and various metal cutting parameters is set forth.

Construction of the regenerators of glass melting tank furnaces needs careful thought to enable them to outlive the tank proper. Some of the important considerations in designing regenerators and selecting the refractories for their constructions are discussed here.

Summary A case of malignant mucocele of the appendix caused by constriction of its base at the neck of a femoral hernial sac is described. No similar case has been found after a careful search of the literature.

Emergency repressurization of space simulation chambers to test apollo vehicle and train astronauts

A generalized expression for electromagnetic polarization under level crossing in a single-mode gas laser is derived up to the third order in the field strength. This is made possible by the use of the probability integral of complex arguments to avoid the Doppler limit approximation. The level crossing effect is seen to appear in the third order, and its linewidth is shown to be asymmetric. It is also broader than the Lorentzian shape usually obtained under the Doppler limit. The dimensionless intensity parameter of the laser field is seen to lose its symmetry about the resonance value in the presence of level crossing. This is attributed to incoherence among different transitions. Further, the other terms like those describing the two-photon process in the third-order value are briefly discussed.