Quantitative metallography with a digital computer: Application to a Nb-Sn superconducting wire

Abstract

Accurate quanti tative data pertin c nt to the structurc of solid m a terials at the micro size level, w hi ch a re diffi cul t or prohibi tive to ob ta in by trad itiona l manual measure ments are ~ow o btain e~ direc~l y b.v a dig;ital co mpu ter wh ich uses a photomicrograph a s the infor: m atlO n lI1pu t. The histo ry of picture in terpretation experime nts at the Natio na l Bureau of Standards. is. reviewed: The f undamental computer ope ration s are illustrated, together wit h a descnp tlOn of 24 unage processing r outin es no\\" funct ional at a practical level. " . A mi.crograph of a spec ime n of Nb-Sn s up erco ndu ctor wire is exha ustively a na lyzed. IIns SpeCI}lle ll IS found to conta ll1 approxImate ly 70 percent Nb3Sn, nea rly a ll of \\' hi ch i'i mutually lI1terco nn ected . It is a lso fo und that in t hi s Rpecime n the mean free path in the N b3Sn s uperconducting phase i~ onl y 26.5 microns. This sma ll value res ults from th e s pongy str ueture of t h e materi a l and numerous in terruptions caused by voids a nd by part icles of four other solie! phases . The comparative importance of the severa l t ypes of i nte rrup tio ns is m easured. I t is determ ined t hat small vo ids a re the most impor ta nt s ingle ca use of th e short m ean free path , a nd deduced t hat t hese \'oids a ppea r to ha ve formed main ly from the reaction dUI'ing heat treatment.

Automated Biomonitoring Using Real Time Movement Analysis of Euglena gracilis

“…After the early work on the use of computers in quantitative image analysis (Moore and Wyman, 1963;Moore, 1964) it took many years until they could be used to analyze the movement of organisms. In the 1980s systems were developed for detecting the movement of "sh or microorganisms (Yachaida et al, 1981;HaK der and Lebert, 1985).…”

Image Processing Problems in Research on Aerosols and Biological Rheology

“…Problems in automatic scanning of irregular particles and in lineal analysis have been treated by workers such as Hawksley (1954), Smith and Guttman (1953). Allio and Randall ( 1962), Moore ( 1963), and Moore and Wyman ( 1963). Their theoretical and experimental developments facilitate the making of statistical inferences about one-, two-, and three-dimensional geometric properties of particles and other microstructures on the basis of two-dimensional scans of images of random sections.…”

Standard Reference Materials :

“…For iron, the corresponding determinations were 9 and 16, respectively. This gives a total of 108 separate nickel determinations and 25 separate iron determinations.…”

“…The computer which has been used to date is the SEAC ( At present, 28 general operations may be performed on a suitable micrograph. Many of these have been described previously [9]. New operations used in this study are known as "SLICE," "BLOB TRANSFER," "BLOB CUSTER," and "STATIS-TICS" respectively and these will be described herein.…”