Terminal Congestion Research Articles

Notes on the Flow of Scheduled Air Traffic

Some of the effects upon air traffic of scheduling the aircraft and of controlling them en route are presented quantitatively in this report in the form of theoretical studies of four problems: (1) relations between the random en route deviations of aircraft from their schedules, and the resulting stack and total delays; (2) effectiveness of a single en route control point when (a) it reschedules the aircraft in an attempt to reduce terminal congestion; (b) it attempts to bring each plane back onto its original schedule; (3) congestion caused by relaxing the schedule; (4) effect of a sudden shutdown of the terminal. The limiting cases of random arrival and continuous control are discussed briefly, and some aspects of multipoint discrete en route control are treated. Numerical analysis, using IBM punched-card machines, is employed extensively in the first three problems. The fourth problem has been simplified enough so that purely analytic methods could be applied. It is presented merely for comparison purposes.

DIETARY LESIONS OF THE PANCREAS

<h3>A. OBSERVATIONS ON MAN</h3> IN THE course of observations on infants fed diets lacking animal protein, it was found that the first clinical sign of the deficiency syndrome characterized by fatty liver and edema was a decrease and then more or less complete cessation of the pancreatic excretory function. The pancreatic failure took some time, about seven to fourteen days, to appear after the deficient feeding had begun, but it was noted that the younger the subject the earlier the symptoms started. The condition proved to be reversible if sufficient amounts of milk could be given before a final stage was reached.¹ Owing to difficulties imposed by postwar conditions, only a few autopsies could be performed. According to these, the macroscopic appearance of the pancreas was, apart from terminal congestion, normal. Histologic examination revealed in several infants that the acinar cells became small, atrophic and angular and separated from