The adsorption of acetic and oleic acids on the surface of thoria was studied by means of infrared spectroscopy. An infrared analysis of the adsorbates before and after adsorption using differential double bean methods indicated that the adsorption of organic acids on thoria surfaces occurs by an esterification reaction between the organic acid and the hydroxylated thoria surface. Ammonia vapor will not adsorb on thoria, indicated the basic character of the hydroxylated surface.

This technical report constitutes a brief review of the work undertaken, entirely or in part, under the Contract AT(30-1)-1772 with eh United States Atomic Energy Commission. The work published during 1959 is listed at the end of this report and copies of the reprints or reports are attached where available. These investigations have been concerned with the examination of defect production and behavior as it may be observed by high frequency ultrasonic attenuation and velocity (modulus) changes in such materials as quartz, silicon, germanium, alkali halides (especially NaCl and XCl), high purity aluminum, and glass containing boron. The irradiations used are cobalt 60 gamma-ray irradiation and the reactor irradiation obtained in the Brookhaven National Laboratory graphite reactor.

Attempts to secure a high degree of synchronization of cell division of the Krebs mouse ascites carcinoma, by combined use of aminopterin and citrovorum factor, and by use of colchicine and N-acetyl colchinol, were unsuccessful. In the course of the work, a new method for securing smears of ascites tumor cells was out, which we believe will be found useful

The chief purpose of this contract is the development of ceramic materials with high dielectric constant and high dielectric strength values, and suitable for use of dielectrics in capacitors capable of storing large amounts of energy in small volumes. Work performed during the fourth quarter included (1) Material development and sample preparation; (2) Sample testing; (3) discussion of ceramic density measurements; (4) Optical studies of titanates; (5) Fabrication of large ceramics; and (6) Capacitor design.

Infrared spectra of solid NaXO2(Ac)3, with X=U, Np, Pu, and Am, have been observed. From the symmetric and asymmetric stretching frequencies of the O-X-O groups, approximate X-O force constants have been calculated and were found to decrease in the order kU—O>kNp—O>kPu—O> kAm—O, the respective values being about 0.705, 0.698, 0.675, and 0.612 megadyne/cm. From the cell constants for NaXO2(Ac)3 it is apparent that the X-O bond distance decreases in the same order—RU—O>RNp—O>RPu—O>RAm—O. Thus, a decrease in bond distance appears to be accompanied by a decrease in force constant, probably because the bond, though shortened by contraction of the electron shells of the metal, is weakened by interaction with the extra valence shell electrons.

This is the thirty-seventh progress report of the Laboratory for Nuclear Science at the Massachusetts Institute of Technology. Progress during the period of June 1, 1955 through August 31, 1955 is reported on: (1) Chemistry of the fission elements group, (2) Nuclear chemistry (inorganic) group, (3) Nuclear chemistry (organic) group, (4) Cosmic ray group, (5) Elementary particle scattering group, (6) neutron physics group, (7) ONR generator group, (8) Radioactivity group, (9) Cyclotron group, (10) Synchrotron group, (11) Theoretical group, (12) Personnel listing.