The Absolute Abundance of the Chromium Isotopes in Some Secondary Minerals (open access)

The Absolute Abundance of the Chromium Isotopes in Some Secondary Minerals

From abstract: "Isotopic assays have been made on the chromium in samples from fourteen different chrominiferous minerals from different geographic and meteoritic sources. The results of the assays indicate that it is not possible to unequivocally state that variations in isotopic compositions have been observed."
Date: 1962
Creator: Svec, Harry J. (Harry John), 1918-; Flesch, G. D. & Capellen, J.
System: The UNT Digital Library
Acid-Base Equilibria in Tertiary Butyl Alcohol (open access)

Acid-Base Equilibria in Tertiary Butyl Alcohol

From abstract: "The dissociation of acids in tertiary butyl alcohol has been studied by potentiometric, spectrophotometric, and conductimetric methods. Values for the over-all dissociation of perchloric and picric acids and several tetrabutylammonium salts were estimated by the Fuoss-Kraus treatment of conductance data. Potentiometric studies were carried out at constant ionic strength in order to minimize activity coefficient variations. An acidity scale was established from potentiometric measurements at a glass electrode, and conductance values of dissociation constants. A method was developed for the evaluation of the over-all dissociation constant of weak acids using potentiometric data for hydrogen ion activities and conductance data for the corresponding anion activities. Over-all dissociation constants are reported for perchloric acid, picric acid, 2,4-dinitrophenol, and benzoic acid. Apparent dissociation constants from potentiometric measurements at a constant ionic strength were determined for hydrobromic, nitric, hydrochloric, picric, and p-toluenesulfonic acids."
Date: August 6, 1962
Creator: Marple, Leland & Fritz, James S. (James Sherwood), 1924-
System: The UNT Digital Library
Acid-Base Reactions and Kinetics of the Halates in Fused Nitrates (open access)

Acid-Base Reactions and Kinetics of the Halates in Fused Nitrates

From Abstract : "The mechanism of the reactions of the halates, bromate, chlorate, and iodate, with dichromate in fused alkali nitrates has been shown to involve a fast equilibrium followed by a slow rate determining strip to give oxygen and halogen gases as final products." Experiments outlined serve as insight into the structure of fused salts or fused electrolytes.
Date: November 1962
Creator: Schlegel, James Max & Duke, P. R.
System: The UNT Digital Library
The Adsorption and Surface Reactions of Hydrocarbons on Clean Iridium (open access)

The Adsorption and Surface Reactions of Hydrocarbons on Clean Iridium

From abstract: "The adsorption of ethane, ethylene and acetylene on clean iridium in a field emission microscope has been found to cause characteristic changes in the work function of the iridium surface. Further changes, which are time and temperature dependent, result when such surfaces are heated. Flash filament experiments have shown that the changes in work function upon heating are due to desorption reactions and that the desorbed product consists principally of hydrogen. By assuming a linear relationship between surface coverage and work function, it has been possible to determine the desorption kinetics from the observed rates of work function change at various temperatures. The results are consistent with a mechanism involving stepwise surface dehydrogenation in which a pair of hydrogen atoms is removed from the hydrocarbon molecule in each step, followed by desoption of the adsorbed hydrogen. At very high temperatures the remaining carbon atoms are removed, presumably by evaporation."
Date: April 7, 1962
Creator: Arthur, John R., Jr. & Hansen, Robert S.
System: The UNT Digital Library
Analysis of Carbon Monoxide-Nitrogen Mixtures by High Resolution Mass Spectrometry (open access)

Analysis of Carbon Monoxide-Nitrogen Mixtures by High Resolution Mass Spectrometry

From abstract: "A single focusing mass spectrometer has been converted into a double focusing instrument. Relatively high resolution is obtained by decreasing the slit widths and minimizing the ion-optic aberrations. A relatively low ion accelerating voltage (2000 volts) is utilized compared to those normally used for high resolution work. The entire construction was performed at these laboratories. Essentially all of the original equipment was reused in the double focusing system. Although the original source slit was decreased from 10 to 0.4 mils and the source α value was decreased from 0.04 to 0.008 radians, sufficient sensitivity is obtained for quantitative gas analysis with the ordinary electrometer tube amplifiers utilizing 4 x 10[^]10 ohms input grid resistors and 100 per cent inverse feedback. Carbon monoxide-nitrogen mixtures were analyzed quantitatively. The results indicate that direct quantitative analysis can be obtained on mixtures ranging from 99 per cent to 10 per cent carbon monoxide in nitrogen. Analysis of lower percentages may be made possible through indirect reading of the peak should it be necessary. It appears that the instrument should be adaptable to research problems concerning these two gases. The immediate problem posed is the analysis of oxygen and nitrogen in metals. Other …
Date: February 1962
Creator: Conzemius, Robert Joseph & Svec, Harry J. (Harry John), 1918-
System: The UNT Digital Library
Angular Distribution of Relativistic Atomic K-Shell Photoelectrons (open access)

Angular Distribution of Relativistic Atomic K-Shell Photoelectrons

From abstract: "Using the high energy limit of the exact Coulomb wave function for the outgoing electron, the differential cross section, correct to three orders in aZ, is calculated for the K-shell photoeffect. An analytic expression, exact in aZ, is obtained for the differential cross section for the special case in which the electron emerges in the forward direction."
Date: 1962
Creator: Weber, T. A. & Mullin, C. J.
System: The UNT Digital Library
The Application of Wax Laps to Vibratory Polishers (open access)

The Application of Wax Laps to Vibratory Polishers

From introduction: "In this paper the adaptation of the wax lab surface vibratory polisher is described. The wax lap requires little maintenance during the life of the lap. It is not necessary to remove any of the holding devices on the bowl to clean and recondition the lap. The bowl is merely washed out, recharged and placed in operation. The wax lap will not wrinkle or tear, nor is it necessary to change it each day such as the silk or nylon cloths."
Date: April 19, 1962
Creator: Hopkins, E. N. & Peterson, D. T.
System: The UNT Digital Library
Automatic Recording Surface Balance (open access)

Automatic Recording Surface Balance

From introduction: "We have previously described simple modifications of a 'Cenco' hydrophil balance which allowed automatic recording of monolayer compression characteristics. This note describes the torsion balance and trough designed and built in this Laboratory as a result of our experience with the previous instrument."
Date: 1962
Creator: Mann, J. Adin, Jr. & Hansen, Robert S.
System: The UNT Digital Library
Boiling Points and Surface Tensions of Mixtures of Benzyl Acetate With Dioxan, Aniline and Meta-Cresol (open access)

Boiling Points and Surface Tensions of Mixtures of Benzyl Acetate With Dioxan, Aniline and Meta-Cresol

Technical report. From Abstract : "Accurate measurements on boiling points and surface tensions of mixtures of benzyl acetate with dioxan, aniline and meta-cresol over the entire range of concentration are reported. The results have been analysed in terms of quasi-crystalline model which is partially successful in representing the composition dependence of heats of mixing, boiling points and surface tension except for composition dependence of boiling points of benzyl acetate and meta-cresol."
Date: September 13, 1962
Creator: Katti, P. K. & Chaudhri, M. M.
System: The UNT Digital Library
Calcium (open access)

Calcium

Technical report outlining the element calcium as well as its occurrences, physical properties, chemical properties, methods of manufacture, economic aspects, and uses.
Date: September 1962
Creator: Carlson, O. N. & Haefling, J. A.
System: The UNT Digital Library
Cation Exchange in Acetone-Water-Hydrochloric Acid (open access)

Cation Exchange in Acetone-Water-Hydrochloric Acid

Abstract: Distribution coefficients have been measured for the partition of metal ions between cation exchange resin and acetone-water-hydrochloric acid solutions. the differences in distribution coefficients of metal ions are greater in acetone-water media than in aqueous media of the same hydrochloric acid concentration. Using distribution coefficient data, conditions for column separations of mixtures can be selected. Column separations of metal ion mixtures can be effected by eluting with acetone-water-hydrochloric acid solutions of different compositions. Successful separations of a number of mixtures are reported.
Date: May 10, 1962
Creator: Fritz, James S. (James Sherwood), 1924- & Rettig, Thomas A.
System: The UNT Digital Library
Cation Exchange Separation of Divalent Metal Ions From Rare Earths (open access)

Cation Exchange Separation of Divalent Metal Ions From Rare Earths

From abstract: "The divalent metal ions of calcium, magnesium, nickel, and strontium are eluted from a cation exchange column with 1.5M nitric acid and separated from trivalent rare earths, aluminum and yttrium. Prior sequential elution of other metal ions with hydrochloric acid in acetone-water or with dilute hydrofluoric acid does not interfere with the present separation method."
Date: June 6, 1962
Creator: Fritz, James S. (James Sherwood), 1924- & Garralda, Barbara B.
System: The UNT Digital Library
The Crystal Structure of Bis(Meta-Chlorobenzoyl) Methane (open access)

The Crystal Structure of Bis(Meta-Chlorobenzoyl) Methane

Technical report. From Abstract : "The crystal structure of bis(meta-chlorobenzoyl) methane has been determined by three dimensional anisotropic least squares refinement of scintillation counter data. The molecule was found to be nearly planar with a maximum deviation from the least squares molecular plane of 0.068Å and an average deviation of 0.023Å. Fourier transform techniques to locate phenyl rings provided the key to the structure determination. The intramolecular bond distances and thermal parameters of the oxygen atoms support a resonant, enol ring with a symmetric, intramolecular hydrogen bond. The structure confirms conslusions from the structure of bis(meta-bromobenzoyl) methane where the symmetry of the molecule was forced by the crystal symmetry."
Date: December 13, 1962
Creator: Engebretson, Gordon R. & Rundle, R. E.
System: The UNT Digital Library
Crystal Structure of Bis (Meta-Chlorobenzoyl) Methane (open access)

Crystal Structure of Bis (Meta-Chlorobenzoyl) Methane

Technical report. From Abstract : "The determination of the crystal structure of bis(meta-chlorobenzoyl)-methane was undertaken by x-ray methods in an effort to clarify the ambiguous position of the hydrogen atom on the enolic form of β - diketones and hence in intramolecular hydrogen bonds."
Date: November 1962
Creator: Engebretson, Gordon Roy & Rundle, R. E.
System: The UNT Digital Library
Discussion of Quadrupole Precession (open access)

Discussion of Quadrupole Precession

From abstract: "In this paper the motion of a nucleus with an intrinsic quadrupole moment in an external electrostatic field gradient is discussed from a classical point of view. It is shown that in the classical approximation the angular momentum may precess about the direction of strongest field gradient or about the direction of intermediate field gradient, but not about the direction of weakest field gradient. The classical precession frequencies are found to be related to the quantum mechanical dipole transition frequencies."
Date: May 31, 1962
Creator: Raich, J. C. & Good, R. H. (Roland Hamilton), 1923-
System: The UNT Digital Library
Effect of Oxygen on Mechanical Properties of Niobium (open access)

Effect of Oxygen on Mechanical Properties of Niobium

From abstract: "The effects of oxygen on some mechanical properties of niobium were studied over the composition range of 20 ppm to 2400 ppm oxygen. The tensile properties of samples of these compositions were studied over the temperature range from room temperature to 500°C. Hardness values were obtained at room temperature only. The following observations and conclusions were made during these studies: 1. Oxygen additions to high purity niobium increase both the yield and tensile strengths of niobium at all temperatures investigated. As the temperature is increased above 250°C the effect of the first 200 ppm of oxygen has more influence than further additions on these strengths of niobium. 2. Strain aging behavior is observed. The peaks in the tensile strength versus temperature curves can be predicted with reliability by the relationship proposed by Cottrell, 3. A mechanism is proposed which, along with Cottrell's segregated atmosphere mechanism, can account for the serrated stress-strain curves obtained. This mechanism offers an explanation of the occurrence of serrations at room temperature, and the mechanism is composition dependent."
Date: May 1962
Creator: Neubauer, Edwin Paul & Wilhelm, H. A.
System: The UNT Digital Library
Electrical Properties of the Tungsten Bronzes (open access)

Electrical Properties of the Tungsten Bronzes

From abstract: "The electrical resistivity of NaxWO3, LixWO3, and KxWO3 has been measured at 300°K. The range of x-values was 0.25 < x < 0.9. All resistivities were characteristic of a metal and lie on a single curve. An extrapolation of the conductivity curve to zero conductivity indicated that the tungsten bronzes should be semiconductors for x < 0.25. The resistivities that have been measured for tungsten bronzes with x < 0.25 showed semiconducting behavior. The resistivity of LixWO3 exhibited an anomalous peak in the ρ vs Τ cuve. The Hall coefficient of Li0.37WO3 indicated one free electron per alkali atom as was previously found for NaxWO3. The Seebeck coefficient of NaxWO3 depended linearly on x[superscript]-2/3 as expected from free electron theory. The implications of these and some other data are discussed."
Date: March 21, 1962
Creator: Shanks, H. R.; Sidles, Paul Howard & Danielson, G. C.
System: The UNT Digital Library
Electrical Resistivity of Rare-Earth Alloys (open access)

Electrical Resistivity of Rare-Earth Alloys

From abstract: "Resistivities of solid solution alloys in the systems Gd-Lu, Tb-Lu, Gd-Er, and Y-Lu were measured from 4.2-320°K to determine the behavior of the resistivity in alloy systems with magnetic phenomena arising from localized magnetic moments. A large contribution to the residual resistivity is caused by the random distribution of these localized moments through the lattice. An analysis of the lattice resistivity of the metals shows large variations across the heavy rare-earth series which are possibly correlated with the change of c/a ratio of the metals and the attendent changes in the Fermi surface geometry."
Date: June 5, 1962
Creator: Smidt, F. A. & Daane, A. H. (Adrian Hill), 1919-
System: The UNT Digital Library
Electron Requirements of Bonds in Metal Borides (open access)

Electron Requirements of Bonds in Metal Borides

From abstract: "Electrical measurements have been made on CaB6, SrB6, BaB6, YB2, YB4, YB6, and YB12 for the purpose of testing models of the electronic structure of the boron atoms in the four boride types represented. The compounds CaB6, SrB6, and BaB6 were found to be semiconductors. The Hall coefficients of YB4 was also measured, but could not be interpreted because the free electron theory does not provide a theoretical value for comparison with experiment. The results are in agreement with the models proposed."
Date: May 28, 1962
Creator: Johnson, Robert W. & Daane, A. H. (Adrian Hill), 1919-
System: The UNT Digital Library
Electronic Spectra of Catacondensed and Pericondensed Aromatic Hydrocarbons (open access)

Electronic Spectra of Catacondensed and Pericondensed Aromatic Hydrocarbons

From abstract: "The electronic spectra arising from the excitations of pi-electrons in homo-nuclear conjugated bond systems are calculated for 37 aromatic hydrocarbons. The theoretical approach used takes into account overlap effects between different a atoms, correlation between different electrons, variations in internuclear distances, and the influence of non-conjugated neighbors, hydrogen and carbon. Four types of approximations are carried trough for the molecules in order to obtain an estimate of the inadequacies of the theory. From the calculated transition energies and oscillator strengths, theoretical spectra are synthesized and compared with observed spectra. In order to help the interpretation, a decomposition of the transition dipoles into atomic contributions is introduced. The spectra of alternant molecules are succesfully predicted, but the limits of the underlying assumptions appear to be exceeded in the applications to non-alternant systems. The calculations are markedly successful for the peri-condensed systems, which had presented an obstacle to previous treatments. It is found that the calculated spectra are fairly sensitive to small variations in interatomic distances. calculations with exact atomic positions, where available, give considerably better agreement with experimental spectra. The calculations lead to an understanding of the general spectral pattern found in all aromatic hydrocarbons. On this basis the …
Date: June 21, 1962
Creator: Hummel, Richard L. & Ruedenberg, Klaus, 1920-
System: The UNT Digital Library
The Enhancement of Acidity of Very Weak Acids in Tertiary Butyl Alcohol (open access)

The Enhancement of Acidity of Very Weak Acids in Tertiary Butyl Alcohol

Technical report. From Abstract : "The acidity of a solution of acid, HX, and salt, MX, is affected by both the concentration of X- and M+ owing to incomplete dissociation of the salt, MX. it was possible to increase the acidity of a solution of 2,6-di-tert-butylphenol - tetrabutylammonium 2,6-di-tert-butylphenolate relative to a dilute solution of tetrabutylammonium hydroxide by increasing the tetrabutylammonium bromide content. This indicates that the dissociation constant of the hydroxide base is sufficiently large that extensive dissociation occurs in dilute solutions. The addition of tetrabutylammonium bromide is therefore recommended as a general method for increasing the acidity and improving the titration characteristics of extremely weak acids."
Date: October 22, 1962
Creator: Marple, Leland & Fritz, J. S.
System: The UNT Digital Library
Experimental Training Model for Closed Chest Cardiac Massage Developed at the Ames Laboratory (open access)

Experimental Training Model for Closed Chest Cardiac Massage Developed at the Ames Laboratory

From introduction: "This article describes a training aid that was at the Ames Laboratory in order to give the plant protection group of the Laboratory an opportunity to practice closed chest cardiac massage on a simulated model. Details of the model are given so that professional or semi-professional people who may be faced with a sudden emergency requiring immediate action may duplicate this training aid."
Date: June 7, 1962
Creator: Padellford, Ralph
System: The UNT Digital Library
Flame Spectra of Vanadium, Niobium, Rhenium, Titanium and Molybdenum (open access)

Flame Spectra of Vanadium, Niobium, Rhenium, Titanium and Molybdenum

Abstract Line spectra of vanadium, niobium, titanium, molybdenum and rhenium of sufficient intensity to allow detection at the 1–10 p.p.m. level can be excited in fuel-rich, oxy-acetylene flames. For the strongest lines of tungsten, the sensitivity of detection is 90 p.p.m. Weak lines of zirconium, hafnium, osmium, tantalum and uranium are also observed in these flames. Recordings of the spectra are given along with wavelength tables of the strongest lines.
Date: July 23, 1962
Creator: Fassel, Velmer A.; Myers, Robert B. & Kniseley, Richard N.
System: The UNT Digital Library
Formation Constants of the Complex Species Formed by Interaction of Rare-Earth Nitrilotriacetate Complexes with an Equivalent Amount of Base (open access)

Formation Constants of the Complex Species Formed by Interaction of Rare-Earth Nitrilotriacetate Complexes with an Equivalent Amount of Base

From abstract: "The formation constants of the RChOH- species, formed by interaction of individual rare-earth nitrilotriacetate species and KOH at 25°C and an ionic strength of 0.1, have been determined by the potentiometric method, i.e., computed from the pH values of equilibrium mixtures containing varying proportions of rare-earth complex and base. The relationship of these constants to the ion-exchange separation of rare earths at high pH has been discussed."
Date: April 13, 1962
Creator: Guptak, Asim K. & Powell, Jack E.
System: The UNT Digital Library