Maximum Limitation Research Articles

An Investigation of Mechanical Strength of Yarn or Cord Twisted with Other Kinds of Filaments

The object of this study is to discover the most effective law of blending and the maximum limitation on the mechanical strength of a blended yarn or cord composed of two kinds of continuous filaments. In the case of tensile rupture, the fibers making up a blended yarn resist the rupture most effectively if the mixing rate of the fibers of low extensibility is under 25% and the twist on the blended yarns is more than half the permissible maximum twist. In the case of flexing fatigue, an ideal blended cord is obtainable if the parameter of S-N diagrams and the mechanical model of the constituent fibers of the blended cord satisfy equation (27). The tensile strength or fatigue life of even the most effective blended yarn or cord is less than that of the mathematical mean of the constituent fibers. The amount of work (the degree of toughness) needed for the tensile rupture of the yarn or cord exceeds the mathematical mean of the constituent fibers.

Transient Voltage and Current Requirements of Main-Field Circuit Breakers for Synchronous Machines [includes discussion

The purpose of this paper is to analyze a number of the basic design and application requirements of main-field circuit breakers forsynchronous machines. The general functions and requirements of main-field circuit breakers are described with typical circuit diagrams. Transient voltages and currents in the excitation circuit are analyzed under normal switching and fault conditions. A basis is suggested for selecting a value of discharge resistance which will bring about the maximum limitation of armature fault damage without creating undue risk of damage to insulation components of the excitation circuit. Equivalent circuits are developed for testing the interrupting performance of the breakers. Suggested constants for interrupting-test circuits are tabulated, as well as values for momentary, short-time, and high-potential tests, over the range of main-field currents and voltages which is anticipated. Interrupting performance tests and a view of a new field breaker for a 250-volt 1,600-ampere circuit are given.

Estimated Cost of Old-Age and Survivors Insurance

Introduction: scope and plan, 427. — I. Oost estimates for the present old-age and survivors insurance program without change: provisions of the program, 429; the high and low assumptions, 430; the estimates, 431. — II. Cost estimates for the old-age and survivors insurance program with assumed changes: the changes considered, 436; change in lump-sum benefit payments, 437; in benefit payments to parents, 438; in minimum monthly benefit limitation, 439; in maximum monthly benefit limitation, 440; in age of eligibility for women, 442; provision of disability benefits, 442; extension of coverage, 443. — Summary of estimates, 450. — Conclusion, 450.

Congress and the Army: Appropriations

Both House and Senate have established separate legislative and appropriations committees and operate under rules designed to exclude legislation from money bills and to deny funds for purposes which Congress has not previously approved. The authorizations generally carry a maximum limitation which allows legislative committees to exercise continuing control and gives Congress some protection against its liberality, although in the two decades between the wars military authorizations ran considerably ahead of appropriations. The appropriations committees influence policy by determining which among authorized programs are to be supported and to what extent, as well as by incorporating “legislation” in Army supply bills, supposedly only when matters are urgent. They usually consult the military affairs and other committees affected, which may offer no criticism or may complain that their jurisdictions and the will of the house concerned have been disregarded. The objection is not merely one of formalities or competition for prestige, but has solid basis in the belief that legislative committees can give more thorough consideration to the implications of new policies than can appropriations committees. Within authorizations, authority over military appropriations is diffused, but control is pretty much by the House Appropriations Subcommittee on the War Department. Its precedence over the Senate committee results, inter alia, from its initiation and more detailed examination of money measures and the latter's self-confinement largely to the rôle of an appellate agency. And the full committee, divided for purposes of expertise and expedition, usually reviews its recommendations only sketchily and hastily.