Applied Spectroscopy

Bryan, Ford R.

doi: 10.1366/000370258774615285pmid: N/A

Some simple statistics are derived from the ten-year bibliography of spectroscopic literature compiled by the Bell Telephone Laboratories and published in Applied Spectroscopy. The numbers of indexed articles are tabulated according to subject, year, and periodical in order to observe publication trends over the period including 1948 through 1957. Among the observations is strong evidence of the desirability of organized technical literature searching to obtain adequate coverage of the literature of spectroscopy.

Strasheim, A.

doi: 10.1366/000370258774615311pmid: N/A

A procedure is described for the precise and convenient construction of preliminary emulsion calibration curves using Seidel values. The method employs the calculation of coordinate points representing averages of readings within specific Seidel unit intervals A standard deviation of 1.15% was obtained for gamma values on repetitive calibration exposures using the described preliminary curve construction techniques. The reading of galvanometer deflection directly in Seidel units is recommended for maximum efficiency.

Hullings, Robert S.

doi: 10.1366/000370258774615366pmid: N/A

An emission spectrographic procedure has been developed for the determination of sodium in residual fuel oil, using a.c. spark, excitation. The analysis is done directly on the oil using the rotating platform electrode technique. This technique may be used for the determination of sodium in the oil, as received, and also for very low concentrations, after the oil has been treated to remove the bulk of the sodium.

Rekus, Andrew F.

doi: 10.1366/000370258774615320pmid: N/A

Indium, which is relatively absent in coal, is described as the ideal internal standard for the determination of potassium in coal ash. The chemical composition of the coal ashes examined varied over considerable limits. The standard deviation was slightly less than % 6±. Indium is also suggested as a possible ideal internal standard for sodium determinations.

Molnar, W. S.; Yarborough, V. A.

doi: 10.1366/000370258774615276pmid: N/A

A novel and simple technique for obtaining infrared spectra of microgram quantities of liquid samples is described. The minute liquid sample is enclosed within a micro capillary tube of polyethylene and the spectrum is recorded with a commercial infrared microspectrometer. A modified cold-trap used with the polyethylene micro-capillaries for sampling minute amounts of liquids eluted from gas chromatographic equipment is also described.

Eikrem, L. O.

doi: 10.1366/000370258774615348pmid: N/A

A direct reading attachment for the Baird-Atomic Three Meter Concave Grating Spectrograph is described. The 20-inch plate-holder is replaced by a “DR Head”, an assembly containing focal curve, exit slits, and photomultiplier tubes. Rapid setting of exit slits is facilitated by use of an electronic slit setting attachment. A separate cabinet contains high and low voltage power supplies, the measuring circuitry, and the clock type reading units. The concentrations of eight different elements may be read simultaneously. Stability of optical alignment is assured by the use of a servo monitor which automatically and continuously keeps the spectrum lines precisely aligned with the exit slits.

Green, Milton

doi: 10.1366/000370258774615302pmid: N/A

In some previous work we have found that for SA-II and 103F emulsions on film the logarithm of the density (log D) prelimininary curves are essentially straight lines. This experimental result leads to a rather simple and convenient expression for the equation of the characteristic curve. For SA-I emulsion on film, we found that the linearty of the log D preliminary curve depends considerable on the wave length region for which the measurements were made and the magnitude of the calibration intensity ratio employed, e.g. the step filter ratio.A more careful analysis of preliminary curves of SA-I emulsions shows the reasons for such a behavior. Actually, the log D preliminary curves are always curved and the degree of curvature varies roughly in proportion to the product of the step ratio of the filter and the gamma at the wavelength at which the measurements are made Probably this same condition exists for SA-II and 103F emulsions, but because their gammas are low, the curvature is not readily observable with a step-filter of moderate ratio.In spite of the curvature of the logD preliminary curve of SA-I emulsions, a straight line fits the data well for the useful range of density measurements for spectrochemical purposes, that is, for a range of densities corresponding to a range of transmittance values between 75% and 1%, the fit is nearly perfect.In attempting to fit various analytical functions, theoretically derived by other investigators, to the erperimental data for SA-I emulsion for the wavelength range 4000A-4200A, it was found that the error function gives the best fit.

Wheat, J. Allen

doi: 10.1366/000370258774615357pmid: N/A

Tin, iron, chromium and nickel can be determined as alloying constituents in Zircaloys by the point-to-plane spark method of spectrographic analysis. Under appropriate conditions this method can be applied to the analysis of rolled sheet and thin-walled tubing as well as to the analysis of masssive blocks Coefficients of variation are four per cent for tin, chromium and nickel, and six per cent for iron.

Smith, A. Lee

doi: 10.1366/000370258774615294pmid: N/A

Devaney, Richard G.; Thompson, Avon L.

doi: 10.1366/000370258774615267pmid: N/A