For several years some of the graduate students, under the supervision of Dr. Scherer, have been investigating the chemical, or physical, reactions which take place in xanthation of soda cellulose. Following the previous work carried out by Scherer, Miller (1), Lin (2), and others in determining the effect of various factors (i.e. effects of temperature and aging) on rate of xanthation, the purpose of this investigation was to determine the effect of bulk number, or degree of mechanical subdivision, on rate of xanthation. In studying this it was hoped to find additional information on the relation between structure of soda cellulose and its reactions with carbon disulfide. It is possible to eliminate the factor of mechanical subdivision from consideration of the rate of reaction between CS₂ and soda cellulose. The only apparent effect is that the denser material offers greater resistance to solution and in that way very slightly modifies the degree of xanthation owing to the necessity for a somewhat longer dispersion period with the resultant possibility of decomposition. The effect of bulk number variation on either rate of reaction, or distribution of the carbon disulfide, was well within the limit of experimental error and may be disregarded. / M.S.

A method of extracting gallium from a Virginia feldspar has been determined. The steps in this method are: 1. Grinding of the ore to a very small particle size (200 mesh) 2. Extraction of gallium by “leaching” the ore with sodium hydroxide 3. Acidification of the sodium hydroxide solution with hydrochloric acid and subsequent extraction of the acid solution with ether to separate the gallium from aluminum, vanadium, and titatium, and other metals 4. Removal of iron by precipitation of ferrous sulphide with hydrogen sulphide 5. Precipitation of gallium by cupferron 6. Ignition of the cupferron precipitate to gallium oxide / M.S.

M.S.

The objectives of the study were three-fold: first, to present a picture of the family patterns and the attitudes and behavior of the youth in a selected group of families; second to study the association between the family patterns and the attitude of the youth; and third, on the basis or the findings of the study to offer suggestions for helping parents and children maintain a more wholesome parent-child relationship. / Master of Science

In the preparation of practically all chemicals there is the necessity of drying, either of the final product or of one or more of the materials used in its preparation. If the material is in solution, or in a suspension, it can be easily handled by drying upon the surface of an internally heated drum. Continuous sheets such as paper and cloth are also dried this way. If the material is easily damaged by high temperatures it may be dried under a partial vacuum. Considering their adaptability, ease of operation, and relative efficiency of operation, it is not surprising that the drum driers are extensively used... / Master of Science

Master of Science

Spray drying is the process by which the solids are recovered from a liquid solution or slurry by spraying the liquid into a stream of heated drying gas under certain conditions which permit recovery of a dry, granular product. Some of the factors which govern the characteristics of the product are: (a) the physical and chemical nature of the substance; (b) the amount of drying gas used; (c) the size of the droplets; (d) the temperature of the inlet drying gas; (e) the concentration of the solution; (f) the temperature of the solution; and (g) the rate of solidification of the substance. It was the purpose of this investigation to design and construct an adequate, laboratory-size spray dryer, together with the necessary auxiliary equipment, and to study the effects of variation in the degree of atomization, the amount of drying air, and the concentration of the solution on the drying conditions and the physical characteristics of the dried material. Only inorganic materials were used in this investigation. Preliminary tests were made with magnesium sulfate and sodium sulfate in order to get the dryer to function properly. Four tests were made, using sodium sulfate solutions, in order to determine the effect of the degree of atomization. Three tests were made, using sodium sulfate solutions, in order to determine the effect of the amount of drying air. Five tests were made, using sodium chloride solutions, in order to determine the effect of concentration of solution. One test was made using a ten per cent (by weight) solution of sodium bicarbonate. The physical characteristics of the dried materials determined were total water content and moisture content, bulk density, particle size, and the nature of the particles. It was found that magnesium sulfate dried as a mixture of hydrates; that the two-fluid nozzle used did not give much variation in the degree of atomization above an air pressure of 20 pounds per square inch gauge; that the moisture content of the spray-dried sodium sulfate distinctly varied with the amount of drying air, but the bulk density or particle size did not; that the bulk density and moisture content of the spray-dried sodium chloride did not vary appreciably with the concentration of the solution dried, while the particle size seemed to vary erratically with the concentration; and that sodium bicarbonate solution when spray dried gave sodium bicarbonate which was to some extent decomposed to sodium carbonate. / Master of Science

Master of Science

Master of Science

A complete summary of this thesis would be too lengthy due to the amount of material covered, so only the most important points will be brought out. (a) The journal bearing is one of the most important elements of machinery. (b) An outline of the fundamentals of oiling and grooving bearings has been given. The bearing metals and the lubricants in use today and the functions of the lubricating engineer have been discussed. (c) Present day journal bearing practices have been described for the following types of equipment: automobile engines, aircraft engines, Diesel engines, steam turbines, electric motors, and generators, rolling mills, railroad cars and engines, heavy duty equipment, line shafting, gyroscopes, ships and steam engines. (d) The basic theory of the perfectly lubricated journal bearing is understood, but exact mathematical solution of the phenomena occurring within the bearing is as yet impossible. (e) By coordinating mathematical investigation and experimental evidence, a fairly good analysis can be made of journal bearing behavior. (f) Needs rational method of designing bearings is a good example of well coordinated mathematical investigation and experimental results. This method of analysis gives the designer a fairly accurate indication of the performance of a journal bearing to be expected. (g) Because of the limitations of theory a large number of manufacturers do extensive research and experimental work in conjunction with their products, to aid in the development of the Journal bearings used. (h) Those interested in further study on this subject are advised to study references 79 and 80 in addition to those already mentioned. Reference 79 is a survey of bearing practice undertaken in 1934 by H.A.S. Howarth. This survey is a valuable adjunct to this thesis, yet is too long to repeat here. Reference 80 is another article by Howarth summarizing the important formulas and charts that had been offered by bearing analysts during the years prior to 1935. / Master of Science