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Determination of the Single Interstitial Migration Energy From Stored Energy and Thermal Resistivity Changes in Irradiated Graphite (open access)

Determination of the Single Interstitial Migration Energy From Stored Energy and Thermal Resistivity Changes in Irradiated Graphite

The model used to evaluate the single interstitial migration energy from property changes due to interstitials is extended to account for vacancy contributions. The annealing function obtained can be used to determine the relative contributions of the defects and is sufficiently sensitive to distinguish vacancy effects that are an order of magnitude less than interstitial effects. Application of the model to stored energy and thermal resistivity data yields the same values of the activation energy and temperature independent term obtained from c-axis and macroscopic length expansion rates. The results indicate that the stored energy associated with the di-interstitial is at least ten times greater than the stored energy associated with the vacancy. The minor role of vacancies in phonon scattering is discussed. Analysis of the annealing function obtained from electrical resistivity changes in irradiated graphite indicates that the ratios of charge-carriers to scattering centers varies with irradiation temperature below 55°C. Above this temperature the changes are attributed to equal contributions from vacancies and interstitials.
Date: March 26, 1963
Creator: Schweitzer, Donald G.
System: The UNT Digital Library
Fundamentals of Vacuum Technology (open access)

Fundamentals of Vacuum Technology

Vacuum technology is germaine to and is utilized in an extroardinarily widespread scope of the scientific disciplines. From the medical technician freeze drying hog cholera vaccine to the solid state physicist studying thin film phenomena, vacuum technology is an important auxiliary. When one visits the NASA center at Langley and sees the clustered space environmental chambers, looking like a field of grotesque mushrooms, one realizes that vacuum technology is a vital adjunct in this most recent section of our total national scientific effort.
Date: March 26, 1963
Creator: Gould, C. L.
System: The UNT Digital Library
A Note Concerning the "100% Value" in Iron Absorption Studies by Whole Body Counting (open access)

A Note Concerning the "100% Value" in Iron Absorption Studies by Whole Body Counting

The evaluation of iron absorption using a single crystal whole-body counter is complicated by the inherent difficulty of determining a correct "100% value". Shortly after ingestion, tracer radioiron can be found in the stomach, upper small intestine, portal circulation and liver. Fourteen to twenty days later, the time at which absorption is measured most effectively, the radioiron will be distributed between the red cell mass, liver, spleen, bone marrow and other storage areas. With this mixed distribution there will always be an error because of geometric factors, and hence in counting efficiency, in using the relationship of [formula not transcribed] to calculate iron absorption. In a previous iron absorption study reported from this group, the radioiron retention measured 4 to 10 hours postingestion was used as the "100% value". The present experiments were designed to evaluate the clinical usefulness of the 4 hour postingestion count as the "100% value" as compared to the immediate postingestion body count, and to compare these values with an intravenous Fe59 calibrated absorption. These studies were performed with the realization that there is no absolute solution to the problem.
Date: March 26, 1963
Creator: Schiffer, L.; Price, D. C.; Cuttner, J.; Cohn, S. H. & Cronkite, E. P.
System: The UNT Digital Library
Polymerization in Solid Solutions of Acrylamide in Propionamide (open access)

Polymerization in Solid Solutions of Acrylamide in Propionamide

It has previously been shown that the polymer formed in solid state polymerization of acrylamide is amorphous in spite of the fact that the reaction takes place within a crystalline solid. The stage at which it becomes amorphous is not known at present. Work with dilute solid solutions of acrylamide in propionamide suggests that this occurs after the addition of, at most, a very few monomer units.
Date: March 26, 1963
Creator: Adler, G. & Reams, W.
System: The UNT Digital Library
The Inference of Adsorption from Differential Double Layer Capacitance Measurements (open access)

The Inference of Adsorption from Differential Double Layer Capacitance Measurements

From Abstract : "Dependence of boundary tension and capacitance at the mercury-aqueous 0.1 N HClO4 interface on polarization and organic solute concentration were determined for the colutes n-amyl alcohol and phenol. ... An earlier treatment proposed by this Laboratory based on a (non-thermodynamic) assumption of linear variation of surface charge density with coverage appears adequately justified for inference of fractional surface coverages near the electrocapillary maximum, but must be considered approximate for evaluation of molar area at full coverage in cases where linear variation of charge with coverage has not been demonstrated."
Date: April 26, 1963
Creator: Hansen, Robert S.; Kelsh, Dennis J. & Grantham, D. H.
System: The UNT Digital Library
The Thermal Expansion of Thirteen Tungsten Carbide Cermets from 68 to 1800 F (open access)

The Thermal Expansion of Thirteen Tungsten Carbide Cermets from 68 to 1800 F

The linear thermal expansion of thirteen tungsten carbide cermets with cobalt binder was investigated experimentally over the temperature range from 68 to 1800 F. Cobalt contents varied from 2.5 to 60 per cent. Several compositions included additions of mixed carbides of titanium, tantalum, and columbium. The experimentally observed coefficients of thermal expansion for the various compositions were compared with coefficients analytically computed from the coefficients for the constituents. Three such analytical methods were evaluated. In one method, the coefficient of expansion of the mixture was computed by volume fractions and in a second method by weight fractions. In the third method, the computation accounted for the stresses set up in the mixture by the difference in thermal expansion of the carbide skeleton and the cobalt binder. The expansions of all these cermets agreed with the values computed by weight fractions or by the stress method within 12 per cent, and by volume fractions within 28 per cent. The cermets containing less than one per cent mixed carbides agreed with the expansion computed either by weight fractions or by stress within 8 per cent, the cermets containing more than five per cent mixed carbides agreed with values computed by volume fractions …
Date: April 26, 1963
Creator: Harrington, L. C. & Rowe, G. H.
System: The UNT Digital Library
Colloidal Radioalbumin Aggregates for Organ Scanning : presented at 10th Annual Meeting, Nuclear Medicine Society, Montreal, Canada, June 26-29, 1963 (open access)

Colloidal Radioalbumin Aggregates for Organ Scanning : presented at 10th Annual Meeting, Nuclear Medicine Society, Montreal, Canada, June 26-29, 1963

Abstract: The exhibit shows that colloidal aggregates (10 to 20 mu) of human serum albumin I131 may be used safely by intravenous injection to perform photoscans of the heart, liver, spleen, stomach, and salivary glands in man. Large particle size suspensions (10 to 50 mu) of the same material are being investigated experimentally in animals for scanning the lungs after intravenous injection and the brain following injection into an internal carotid artery. The advantages of this test material are the relatively low radiation exposure to the target organs and the number of organs that may be examined. Radiation exposure is low because of the rapid turnover in the target organs and removal from the body, mainly by urinary excretion, within 72 hours. The mechanism of liver-spleen localization with this organic colloid is the same as for inorganic colloidal radiogold198, namely, rapid removal from the blood by the phagocytic cells of the liver and spleen. However, in contrast to the inorganic colloid, which remains in the phagocytic cells permanently, albumin is digested by proteolytic enzymes and the I131 abel is set free to re-enter the general circulation. With the thyroid blocked, the I131 is excreted mainly in the urine as free …
Date: June 26, 1963
Creator: Taplin, George V.; Dore, Earl K.; Johnson, DeLores E. & Kaplan, Harriet.
System: The UNT Digital Library
High Power Density Development Project: Potter Meter Calibration and Instrumented Fuel Bundle Pressure Drop (open access)

High Power Density Development Project: Potter Meter Calibration and Instrumented Fuel Bundle Pressure Drop

Summary: Technical report describing the testing of eight Potter Meters, for metering inlet flow and measuring exit steam qualities in the Consumers Big Rock Point Instrumented Fuel Assemblies, were individually calibrated for flow and pressure drop up to 500 gpm in the low temperature (130 F) fluid flow facility. The flow calibration comparison made with an ASME orifice installation, agreed to within + - 1 percent among seven of the meters, and meter Serial No. 8 was 2.8 percent lower than the others. Pressure drop among the meters was within about 5 percent. Locked rotor pressure drop data was obtained on one meter. A fully instrumented fuel bundle was tested in the low temperature facility and pressure drop data obtained for the tieplates and meters, spacers, and channel rods. A mock-up of the exit end of the instrumented fuel bundles, composed of 1 foot of fuel rods, tieplate, and Potter Meter was tested in the High Pressure Heat Transfer Facility. Data was obtained for single- and two-phase calibration of total flow and exit steam quality in an instrumented bundle. Each meter was operated, for a minimum of 6-8 hours after bearing modifications necessitated by seizure of the rotors, in the …
Date: July 26, 1963
Creator: Polomik, E. E. & Swan, C. L.
System: The UNT Digital Library