 554  442. The prevailing concept considers cancers as biologic manifestations which develop in response to carcinogenic stimuli and which assume, once produced, complete biologic independence from the causal agent, thereby becoming disease entities per se. 443. For drilling or tapping units, for which high speeds are required, provision is made for taking drive from the pinion shaft in the main transmission, to enable a step-up ratio of 3:1 to be obtained. A facing head can also be supplied, for securing to the nose of the milling sleeve. 444. During the past ten years travelling-wave tubes have received considerable attention in vacuum tube laboratories, both in this country and abroad. So far their use in operating systems has been somewhat limited, the most notable exceptions being in radio relay service in France, Great Britain, and Japan. 445. A novel method by means of which it has been possible to convert heat directly into electromagnetic energy is based upon operating a thermionic plasma diode in a particular mode of operation and to present some of the experimental results. 446. Speed and direction are both equally difficult to measure and so the available tolerance will be divided equally between these two giving respectively tolerances of 10 m/s and 0.003 radians. 447. Although few data could be obtained, this phenomenon is further shown by the virtual absence of temperature effects on the Walden product, the values obtained at 45° from limiting equivalend conductances in tri-p-totyl phosphite being almost identical with those at 65°. 448. Experimental physics prior to 1900 had demonstrated the exsitance of a wide variety of phenomena, which for the most part were believed to be explicable in terms of what we now call classical theoretical physics. 449. This is a theoretical argument, but if a device is rated for a particular dissipation and a particular peak current maximum, then provided the external circuit conditions are adjusted to prevent these maxima being exceeded, it would seem immaterial whether the current were switched on by gate action, or by anode breakover effect. 554 |
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