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The Action of Penetrating Radiations on Yeast Cells

Description: This report demonstrates that x-rays affect cell division in yeast cells more than metabolism and that radiations cause morphological mutations in these cells.
Date: January 1, 0195
Creator: Tobias, C. A.; Mortimer, R. K.; Gunther, R. L. & Welch, G. P.
Partner: UNT Libraries Government Documents Department

PAR Loop Schedule Review

Description: The schedule for the installation of the PAR slurry loop experiment in the South Facility of the ORR has been reviewed and revised. The design, fabrication, and installation is approximately two weeks behind schedule at this time due to many factors; however, indications are that this time can be made up. Design is estimated to be 56 per cent complete, fabrication 27 per cent complete-and installation 11 per cent complete:
Date: March 31, 0958
Creator: Schaffer, Jr. & W.F.
Partner: UNT Libraries Government Documents Department

Three-dimensional Numerical Investigation of Electron Transport with Rotating Spoke in a Cylindrical Anode Layer Hall Plasma Accelerator

Description: The oscillation behavior described in [Tang et. al, Phys. Plasmas 19, 073519 (2012)] di ers too greatly from previous experimental and numerical studies to claim observation of the same phenomenon. Most signi cantly, the rotation velocity in [Tang et. al, Phys. Plasmas 19, 073519 (2012)] is three orders of magnitude larger than that of typical \rotating spoke" phenomena. Several physical and numerical considerations are presented to more accurately understand the numerical results of [Tang et. al, Phys. Plasmas 19, 073519 (2012)] in light of previous studies.
Date: August 27, 1012
Creator: Ellison, C. Leland; Matyash, K.; Parker, J. B.; Raitses, Y. & Fisch, N. J.
Partner: UNT Libraries Government Documents Department

The Precipitation of Uranium Peroxide in the Presence of Fluorides

Description: The large-scale recovery of uranium from materials which also contained great quantities of fluorides did not give a product which had a low enough fluoride content to be treated satisfactorily by the other extraction process. The objective of the investigations carried out in this laboratory was a method of reducing the amount of fluoride which accompanied the uranium. The material from which the uranium was recovered in the industrial process was a slag containing (in addition to uranium) magnesium fluoride, calcium and dolomitic lines, crucible dross, and other waste products from the reaction of magnesium metal and uranium hexafluoride. Most of the fluoride was removed from this mixture by heating the roasted and ground slag with sulfuric acid. The residue was mixed with water and much of the caclium sulfate and fluoride, magnesium fluoride, and hydrated ferric oxide and alumina was precipitated by reducing the acidity. After filtering off the precipitate, ammonium sulfate was added to the solution and uranium peroxide (UO{sub 4} {center_dot} 2H{sub 2}O) was precipitated by addition of hydrogen peroxide. The pH of the solution was maintained between 3.0 and 3.5 during the precipitation by addition of sodium hydroxide. The uranium peroxide, even after washing, contained between 2 and 3% fluoride. The percentage of fluoride could be reduced to 0.5% by precipitating the peroxide from a more acidic solution but this required the use of much larger amounts of hydrogen peroxide.
Date: January 1, 1941
Creator: King, Edward J.
Partner: UNT Libraries Government Documents Department

Production of DsSub 2$O for Use in the Fission of Uranium

Description: Brief discussions of experimental methods, kinetics, and the catalysts used in the production of D{sub 2}O are presented (J.E.D.)
Date: June 23, 1941
Creator: Urey, H. C.; Grosse, A. V. & Walden, G.
Partner: UNT Libraries Government Documents Department

Chemical Properties of Uranium Hexafluoride, UF6

Description: Uranium hexafluoride has the distinction of being the only stable gaseous compound of uranium known up to the present moment. Because of this property it is the only compound that can be used for processes of isotope separation, such as diffusion, thermal diffusion, centrifuge separation, distillation, and other of a similar nature. Here is a short description of the properties of UF{sub 6} and is intended for a reader interested only casually in this compound. UF{sub 6} is a very reactive compound and a very strong fluorinating agent. It is immediately hydrolized by water. In fluorinating reactions it is reduced to the green highly stable UF{sub 4}. It reacts instantaneously with hydrogen at room temperature. It fluorinates many metals; sodium and mercury are attacked in the cold, lead, zinc, tin and iron on heating; platinum and gold react only above 400 C. With organic compounds like alcohol, ether, benzene or toluene, immediate fluorination takes place with formation of HF and carbon or carbonaceous material. The compound forms colorless, very volatile, beautiful transparent crystals of high refractive index. Melting point = 69.5{sup o}; boiling point at 760 mm = 56.2{sup o}; D20{sup o} = 4.68. The crystals melt water pressure to a transparent colorless liquid of high density, but great mobility.
Date: June 25, 1941
Creator: Grosse, Aristid V.
Partner: UNT Libraries Government Documents Department

Purification of Uranium Oxide

Description: No Description Available.
Date: April 21, 1942
Creator: Hoffman, J.I.
Partner: UNT Libraries Government Documents Department

Establishing Site X: Letter, Arthur H. Compton to Enrico Fermi, September 14, 1942

Description: This letter from Compton to Fermi describes developments bearing on the establishment of ``site X`` (which, as of the letter date, is definitely determined as at the Tennessee Valley) for the construction of a pile and associated pilot plant buildings, describes the situation as of the letter date, and offers counsel as to how to proceed.
Date: September 14, 1942
Creator: Compton, A. H.
Partner: UNT Libraries Government Documents Department

Theory of High Frequency Rectification by Silicon Crystals

Description: The excellent performance of British ''red dot'' crystals is explained as due to the knife edge contact against a polished surface. High frequency rectification depends critically on the capacity of the rectifying boundary layer of the crystal. C. For high conversion efficiency, the product of this capacity and of the ''forward'' (bulk) resistance R{sub b} of the crystal must be small. For a knife edge, this product depends primarily on the breadth of the knife edge and very little upon its length. The contact can therefore have a rather large area which prevents burn-out. For a wavelength of 10 cm. the computations show that the breadth of the knife edge should be less than about 10{sup -3} cm. For a point contact the radius must be less than 1.5 x 10{sup -3} cm. and the resulting small area is conductive to burn-out. The effect of ''tapping'' is probably to reduce the area of contact.
Date: October 29, 1942
Creator: Bethe, H.A.
Partner: UNT Libraries Government Documents Department

The Production of Uranium Metal by Metal Hydrides Incorporated

Description: Metal Hydrides Incorporated was a pioneer in the production of uranium metal on a commercial scale and supplied it to all the laboratories interested in the original research, before other methods for its production were developed. Metal Hydrides Inc. supplied the major part of the metal for the construction of the first experimental pile which, on December 2, 1942, demonstrated the feasibility of the self-sustaining chain reaction and the release of atomic energy.
Date: January 1, 1943
Creator: Alexander, P. P.
Partner: UNT Libraries Government Documents Department