Paul D. Foote

CAPILLARY RISE IN SANDS OF UNIFORM SPHERICAL GRAINS

Uniform spheres packed in regular array form a non‐cylindrical cyclic capillary, characterized by a maximum and minimum capillary rise with intermediate positions of possible equilibrium. In practice spheres may be packed to a variety of porosities P thus requiring a mixture of regular and irregular pilings arranged in a very distorted pattern. However the meniscus is also distorted to conform in a general way with the distortions of the lattice. Accordingly positions of maximum and minimum rise may be expected. The meniscus for maximum rise tends to pass through the plane of centers of neighboring spheres. Slight deviations from this condition due to the rise at sphere contacts are shown to be of minor importance. Any piling may be treated statistically as a hexagonal array with a spacing 2r+d where d is computed to give the observed porosity. In such a system three types of cell occur with a definite frequency, and these cell types are assumed present in the meniscus with the same frequency distribution...

Optics in the Oil Industry

The employment of optical principles and equipment is vitally important in many operations of the petroleum industry. At the present time the greatest concentration of optical applications is in spectroscopy. Emission spectroscopy is widely used in almost all operations for rapid reliable analyses of materials for metallic or inorganic elements. These applications range from the measurement of metallic elements present in crude oil to the solving of customer complaints where there is a relation between poor performance and the presence of impurities.The techniques of infrared and ultraviolet absorption spectroscopy are quite widely used to solve many analytical and molecular structure problems encountered in hydrocarbon chemistry. Infrared absorption is particularly valuable for distinguishing between close boiling isomers, and the ultraviolet technique is very extensively used in the analysis for various kinds of aromatics. A specialized branch of infrared absorption wherein the selective absorption properties of gases are utilized is becoming of great importance for the continuous monitoring and automatic control of refining processes.An indirect but extremely important application of optics is in the utilization of thermodynamic quantities derived from spectroscopic data. Fairly complete data from this source are available on about 210 hydrocarbons, and today research on any refining process is seldom undertaken until a preliminary study is made of the thermodynamic data. Various aspects of photochemistry and optical activity are important in the oil business. It has been found practical and convenient to utilize ultraviolet light in accelerated stability tests of products subject to deterioration with age. At present it is known that a hydrocarbon of phenomenal octane number may be prepared by photochemical synthesis. In the study of compounds isolated from petroleum it has been discovered that some of them are optically active. At least one of these has been isolated and studied.Aerial photography occupies a very important place in the mapping work involved in exploration and pipe-line surveys. Stereograms are used for contouring purposes to yield satisfactory topographic maps. Many significant surface geological features may be delineated from stereograms and photomosaics. A field allied to mapping and employing the concepts, if not the equipment, of optics is in radiolocation wherein either direct interferometric techniques or time measurements of wave propagation are employed. Other sciences utilizing common optical concepts are x-ray diffraction, electron diffraction, electron microscopy, and mass spectrometry. All of these are essential to the modern research laboratory of the petroleum industry.

The Spectra of Fifth Group Metals

WE have photographed the absorption spectrum of bismuth and also the spectrum of the thermionic discharge at potentials ranging between 4 and 60 volts. Several stages in the excitation of the arc spectrum, and at least two classes of spark lines, have been recognised; 64 arc lines have been classified. The spectrum of the neutral atom is characterised by wide doublets, and most of the energy-levels so far identified are of p-type.

Some Characteristics of the Marvin Pyrheliometer

University of Minnesota Ph.D. dissertation. May 1917. Major: Physics. Advisor: Dr. Stratton. 1 computer file (PDF); 29 pages.

Excitation of Forbidden Spectral Lines

HANSEN, Takamine, and Werner (Kgl. Danske Videnskab. Selskab Mathfys. Medd. 3) have observed the line 1S – 2p1 (Paschens notation) of mercury in a condensed discharge, and Takamine and Fukuda (Phys. Rev. 25, p. 23, 1925) have found the line strongly developed in the glow of a branched arc. We have excited this line, the corresponding line of zinc, and both 1S – 2p1 and 1S – 2p3 of cadmium in the positive column of a hot-cathode discharge. The positive column was viewed end-on while the cathode glow was confined to a side tube. The potential difference across the entire tube was of the order of 100 volts, but the tubes employed were of such length, 30 to 100 cm., that the voltage drop per mean free path of an electron was quite small. The spectrum is strictly of the arc type, only a few of the more readily excited spark lines appearing, and these in comparatively low intensity.

SOME CHARACTERISTICS OF THE MARVIN PYRHELIOMETER

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