Note presenting a study of the impact behavior of normalized SAE X4130 steel after a variety of repeated stress treatments. Fatigue specimens of several types were used and the effects of surface finish, rest periods, stress amplitude, mean stress, stress concentration, and temperature during repeated stress received consideration.

"A number of factors are considered which influence the static and fatigue strength of materials under practical operating conditions as contrasted with the relations obtaining under conditions of the usual testing procedure. Such factors are interruptions in operation, periodically fluctuating stress limits and mean stresses with periodic succession of several groups and stress states, statistical changes and succession of stress limits and mean stresses, frictional corrosion at junctures, and notch effects" (p. 1).

Note presenting a study to gain information as to the fundamental mechanism of fretting corrosion. The specific questions to be answered were whether chemical action played an important role in fretting of metal surfaces and whether any such action would improve the corrosion resistance of the metal investigated. The results indicated that the chemical action is of primary importance in fretting-corrosion effects and oxide formation does not give any protection to the metals but rather increases the rate of wear.

Supplement updating the list of Texas land grants and patents as of 1945, outlining information documenting acreages, grantees and patentees, patent dates, abstract numbers, and other relevant data, organized by county.

Report presenting a summary of the available information on lateral control. Some of the topics include the criterions used in lateral-control specifications, the factors involved in obtaining satisfactory lateral control, and the methods employed in making lateral-control investigations in flight and wind tunnels.

This document contains reproductions of the technical papers presented at the NACA - University Conference on Aerodynamics held at the Langley Aeronautical Laboratory on June 21, 22, and 23, 1948. The conference was held in recognition of the difficulties, imposed by security restrictions, in keeping abreast of the rapid advances in aerodynamics. The papers were prepared to review the status of a number of fields of interest, to summarize the more important wartime advances that are no longer classified, and to orient reference material for further study.

Volume provides abstracts of agricultural experiments conducted during the year. Also includes statistics, convention reports, bulletins, bibliographies, and listings for Spanish edition publications from the Puerto Rico station. Name and subject indexes start on page 871.

Supplement updating the list of Texas land grants and patents as of 1947, outlining information documenting acreages, grantees and patentees, patent dates, abstract numbers, and other relevant data, organized by county.

Volume provides abstracts of agricultural experiments conducted during the year. Also includes statistics, convention reports, bulletins, bibliographies, and listings for Spanish edition publications from the Puerto Rico Station. Name and subject indexes start on page 893.

Volume provides abstracts of agricultural experiments conducted during the year. Also includes statistics, convention reports, bulletins, bibliographies, and listings for Spanish edition publications from the Puerto Rico station. Name and subject indexes start on page 865.

Volume provides abstracts of agricultural experiments conducted during the year. Also includes statistics, convention reports, bulletins, and bibliographies. Name and subject indexes start on page 865.