1. The critical mass of uranium is packed with just enough electrons which, when suddenly brought together with another equal mass of electrons, starts a chain reaction.
2. At first glance it would have been daring to interpret the fission phenomenon in the Uranium nucleus as being due to the rare U235 rather than the U238, which is 140 times as abundant, but this turned out to be the case.
3. The Russians are given the credit of having been the first to clear minefields with sweeps.
Although there are other methods of clearing the sea of mines the sweep still holds pride of position and even its modern form varies very little from original practice as introduced by the Russians.
4. The existing types of gas masks might be subject to great modifications in time of war, for the development in this sphere has not stopped and conditions faced may prove to be different from what they are imagined with the existing experience.
5. This type of transmission line uses a wire inside and coaxial with a tubing outer conductor separated from the other one by insulating spacers at regular intervals.
6. Selectivity is the ability of a receiver to respond to signals from one transmitting station without being affected by or responding to the signals from other stations of nearly the same frequency as the one being received.
7. At radio frequencies where every wire carrying r.f. current tends to radiate energy in the form of electromagnetic waves, special design is necessary to minimize radiation and thus cause as much as possible of the power to be delivered to the receiving end of the line.
8. Clearly, no country that professes to take a realistic and objective view of facts and events can frame its policy without regarding the historic changes wrought or now “being wrought in Asia of our day.
9. For the Party really to play the leading role proper to it in all spheres of public life, every Party worker must work perseveringly and known the job, must always be equal to any situation that arises and have a sense of the new.
Being guided by the Marxist-Leninist teaching makes it easier for the Party worker to exercise a leading role in the everyday work of Socialist construction and in the struggle for the general line of the Party.
10. Following the Geneva conference the situation in Asia seemed to improve somewhat, but there are still glowing embers and one cannot help expressing alarm over the fact that a very large part of the world embracing the whole of South-East Asia is menaced by a new danger as a result of aggressive actions on the part of Americans towards the Chinese People’s Republic.
11. Having had talks with Argentineans from various walks of life, one can easily come to the conclusion that the country’s social temperature is to be gauged in terms of the common desire to put an end to the dependence upon foreign corporations, which has burdened both her industrialization and a rise in the living standard.
12. It is known that in 1945 German designers were experimenting over a long range atomic rocket. But it is fairly certain that the menace could hardly have materialized in time for use in the last war even if it had lasted a year or two longer, for the designers would, fortunately, have been bound to have had heating difficulties at the contemplated speed of the rocket of over 2 miles a second.
13. Early in the twentieth century, very much excited about radioactivity, scientists went exploring with their electroscopes putting them deep into the earth and lifting high in the air.
Having measured the penetrating of alpha, beta, and gamma rays through various shields of metal, the scientists were very much surprised to find that no matter how thoroughly the electroscope was shielded on the ground or how high it was lifted above the surface of the earth, there still were traces of electricity discharged at a certain minimum rate recorded by the measuring instrument, the source of the electricity flow proving to be the so called cosmic rays.
14. Allowing an area to become free of gas after the chemical shell explosion by waiting for the sun, wind, and rain to evaporate, disperse, and wash away a chemical warfare agent is termed weathering.
15. One field in which the skin effect must be taken into account is in the design of resistance standards for use with alternating currents. Here the variation of resistance with frequency can be minimized by using either a single wire of small diameter, or litz, which consists of a bundle of small wires, insulated from one another and so interwoven that any one strand is on the average, near outside of the bundle as much as any other strand. Even with the best design, however, corrections for skin effect must be applied to resistance standards when they are used at very high frequencies.
At ultra-high frequencies the reactance of even a short straight wire may be so great that it must be taken into account, and under these circumstances it is impossible to design circuit elements that can be considered as pure resistances, inductances, or capacitances.