High-speed fringe-follower for interferometry

A high-speed fringe-follower with no mechanical moving parts was constructed. This paper describes the basic principles and the results of the fringe-follower. In this method the phase of the signal is determined by comparing a ratio of two fringe signals, which have phase difference pi/2 from each other, with an electronically generated tangent function. The maximum time required to make one measurement was 10 microsec.

Gas-Liquid Chromatographic Analysis of Indole-3-acetic Acid Myoinositol Esters in Maize Kernels

An improved method of fractionating the myoinositol esters of indoleacetic acid (IAA) from maize kernels by gas-liquid chromatography has been developed. Mass spectrometry was employed as an aid in identification of the esters. Maize kernels contain three groups of esters of IAA: (a) IAA myoinositols, (b) IAA myoinositol arabinosides, and (c) IAA myoinositol galactosides. Each group has three chromatographically distinguishable isomers. The glycosylinositols described are unique in that carbon 1 of the sugar is attached to the hydroxyl at C-5 of the myoinositol.

A Quantitative Estimation of Alkali-labile Indole-3-Acetic Acid Compounds in Dormant and Germinating Maize Kernels

An estimate has been made of the quantities of alkali-labile esters of indoleacetic acid (IAA) in kernels of sweet corn (Zea mays). The amount is between 70 to 90 mg of IAA per kilogram of dry kernels. About one-half of the IAA is present as high molecular weight esters and the remaining one-half as esters of myo-inositol. Free IAA, which may have existed in the kernels, or may have resulted from ester hydrolysis during isolation or storage, amounts to between 1 to 10% of the esterified IAA. Five newly observed low molecular weight indoleacetyl compounds are described and their chromatographic behavior reported. The total IAA content of corn kernels and intact seedlings decreases during germination, declining to about 10% of the original content during 96 hr of germination. Difficulties in obtaining quantitative results and the possible physiological significance of these results is discussed.