 521  222. It is the sun shining on the drops of rain, as they fall, that makes those beautiful colours in the rainbow. It is because every little raindrop is a round ball of water, that the bow itself is curved or round. 223. Serum bilirubin concentrations may be slightly elevated in patients with heart failure and hepatic congestion but a sudden increase in serum bilirubin in cardiac patients has long been known to signify the occurrence of pulmonary infarction. 224. Frequency modulation is accomplished by coupling the modulating signal from the audio amplifier to the base of the oscillator, which causes the oscillator frequency to change. The change is proportional to the amplitude of the audio voltage applied. 225. Thus, an intact hypothalamus and sympathetic nervous system seem to be required for a normal febrile response and complete extirpation of the posterior hypothalamic gray matter prevents the pyrogenic action in most instances. 226. In this example, the forecast was considered to be net income. Sometimes it is preferable to forecast gross income with operating costs remaining constant throughout. This is accomplished by subtracting the present worth of operating costs. 227. Cathodic protection procedures require a low voltage direct current. Thermoelectric generators appear, therefore, to be suited to this application, as their output is d-c in the desired voltage range. 228. Until then only the lodestone was held to be the source of magnetic power. A new and more powerful agency for creating magnetism had thus been discovered. By mathematical analysis Ampere predicted electrodynamic behavior, subsequently proved by experiment. 229. This second master can be in two spool, or endless loop cassette form, the latter probably being the most convenient. This is then played back at a fixed multiple (say 4) of «book speed» by a machine using multiple replay amplifiers, simultaneously, their outputs being fed to the final copy-making machine also running at the same speed. 230. This diode-driving technique and the use of high frequency transistors in the A.G.S. amplifier (fr = 250 mc) results in the frequency response of the A.G.S. loop being controlled almost exclusively by capacitor C. 521 |
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