Sferics

The properties of sferics (the electric and magnetic fields generated by electrified clouds and lightning flashes) are briefly surveyed; the source disturbance and the influence of propagation being examined. Methods of observing sferics and their meteorological implications are discussed. It is concluded that close observations of electrostatic and radiation fields are very informative, respectively, upon the charge distribution and spark processes in a cloud; that ground-level sferics stations can accurately locate the positions of individual lightning flashes and furnish valuable knowledge on the properties of the discharges; but that satellite measurements only provide general information on the level of thundery activity over large geographical regions

Evaluation of Plantings for Wildlife on a Power Line Right of Way in Southern Arkansas

The combination of types of land preparation and species of plants seeded along a power line right-of-way was evaluated in terms of the effects upon wildlife. Relative population densities of plants, birds, and mammals were determined for each of the areas under study. A study of the reduction in maintenance costs in relation to the initial investment for preparation and seeding of the land was mad

Induction probe determines levels of liquid metals

Mutual-inductance probe accurately measures liquid levels in a variety of liquid metals at elevated temperatures. It can be used in pyrochemical processes for the recovery of spent reactor fuel

Measurements in atmospheric electricity designed to improve launch safety during the Apollo series

Ground test measurements were made during the launches of Apollo 13 and 14 in an effort to better define the electrical characteristics of a large launch vehicle. Of particular concern was the effective electrical length of the vehicle and plume since this parameter markedly affects the likelihood of a lightning stroke being triggered by a launch during disturbed weather conditions. Since no instrumentation could be carried aboard the launch vehicle, the experiments were confined to LF radio noise and electrostatic-field measurements on the ground in the vicinity of the launch pad. The philosophy of the experiment and the instrumentation and layout are described. From the results of the experiment it is concluded that the rocket and exhaust do not produce large-scale shorting of the earth's field out to distances of thousands of feet from the launch pad. There is evidence, however, that the plume does add substantially to the electrical length of the rocket. On this basis, it was recommended that there be no relaxation of launch rules for launches during disturbed weather

Symmetric Functions of \u3ci\u3en\u3c/i\u3e-IC Residues (mod \u3ci\u3ep\u3c/i\u3e)

If p be an odd prime, q is said to be an n- ic residue of p if the congruence xn = q (mod p) has solutions; otherwise q is an n-ic non-residue of p. A necessary and sufficient condition that q be an n-ic residue of p is that (1) q (p- 1)/δ ≡ 1, (mod p), where δ = g.c.d. (p - 1, n). The numberf of n-ic residues of a given prime p is (p-1)/δ. It is with the symmetric functions of these n-ic residues that this paper deals