Thesis--Wisconsin. / Vita. Includes bibliographical references (leaves 120-128).

Thesis (M.S. in Astronautical Engineering)--Naval Postgraduate School, December 2006. / Thesis Advisor(s): Christopher M. Brophy. "December 2006." Includes bibliographical references (p. 97). Also available in print.

Thesis--Purdue University. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Chicago, 1922. / "Private edition, distributed by the University of Chicago libraries, Chicago, Illinois." "Reprinted from the Physical review, vol. 21., no. 6, June, 1923." Also available on the Internet.

A critical survey has been conducted on the research done in oxygen isotopes. Only those aspects are considered which are of interest to the earth scientists. Oxygen isotopes have been used for geothermometric purposes and for rock genesis problems. The physical principles underlying these two lines of research are stressed. Assumptions which are usually implied are explicitly stated. It is shown that the influence of pressure on the equilibrium constant of oxygen isotope exchange reactions is only a minor one in comparison with the temperature influence. The significance of determined temperatures is discussed in the light of possible oxygen diffusion in silicates and carbonates. It is concluded that diffusion is usually neglected without justification. As far as data are available it is shown that diffusion can be responsible for many discrepancies between oxygen isotope temperatures and' temperatures derived by other means. Studies on the origin of rocks by means of oxygen isotopes are discussed. Attention is focussed on the Southern Californian batholith. The results of Taylor and Epstein's preliminary study of this batholith are interpreted here as evidence in favour of a metamorphic origin of this huge rock body. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

The bromine afterglow emission was studied using the discharge-flow technique. The spectrum of discharged bromine was observed to extend from 6000Å to 22000Å and has been attributed to the Br₂ (₃Π₀⁺u→¹Ε⁺g) and Br₂(³Π₁u→Σ⁺g) transitions. The dependence of the emission intensity on atom concentration was observed to vary between I ∝ [Br]²•º ±º•¹ at short wavelengths, and I∝[Br]¹•⁵±º•¹ in the long wavelength region of the spectrum. In the pressure range studied (O.5 to 2 torr), the intensity was found to be independent of the molecular bromine concentration. By measuring the absolute emission intensity between 6000Å and 12000Å, values of the apparent rate constant, defined as kapp=I/[Br]²[Br₂], were measured. These rate constants were found to depend on atom concentration and pressure and varied between kapp =5.4 x 10¹³ and 1.3 x 10¹⁵ cc²mole⁻² sec⁻¹. A mechanism of the emission reaction is discussed and it is suggested that as much as 15% of the total recombination of bromine atoms may be proceeding via excited states. In a similar study of the chlorine afterglow, all of the emission was attributed to the Cl₂ (³Π₀ +u —>¹Σ⁺g) transition. A study of the emission intensity in narrow bands revealed that I∝[CI]²•⁰±º•¹ at short wavelengths, corresponding to low vibrational levels of the ¹Π₀+u state, while I ∝ [Cl]¹•⁰±º‧¹ at long wavelengths and higher vibrational levels. Similarly, the pressure dependence of the intensity changed from I ∝ [Cl₂]⁰•⁵± º•² at long wavelengths to I ∝ [Cl₂]⁰•⁵±⁰•² at short wavelengths. Absolute emission intensity measurements were made in the region from 5000Å to 12000Å and the rate constants, defined by kapp = I/[Cl]²[Cl₂], were found. Extrapolation of these values of kapp to zero atom concentration yields kapp = 1.8 x 10¹⁴ cc² mole⁻² sec⁻¹. A mechanism for the formation and relaxation of the excited state is discussed. The study of absolute emission intensities was extended to measurements on excited oxygen molecules in a flow system. Observations on the 7619Å band of the O₂(¹Σ⁺g→³Σ⁻) transition yielded [0₂ (¹Σ⁺g)] = 1.77 x 10⁻⁹ moles 1.⁻¹, thereby confirming that this species is a minor constituent in the products of discharged oxygen. Absolute intensity studies on the 6340Å and 7030Å bands of the (0₂ (Δg))₂→(0₂(³Σ⁻))₂ transition indicate that the half life of the (O₂ (¹Δg))₂ collision complex is around 0.1 seconds. The emission spectrum produced when Cl₂ is reacted with H₂O₂ in solution was observed to originate in various transitions involving excited molecular oxygen. A yield of 0₂(¹Δg)of 10% from this reaction was estimated. / Science, Faculty of / Chemistry, Department of / Graduate

An automated sample preparation line has been developed to equilibrate water samples for determination of their oxygen isotope ratio. Preliminary estimates put the repeatability of the sample preparation methods at approximately 0.04°/oof a figure that compares very favourably with the present state of the art. A noteworthy feature of our sample line, is that temperature control is unnecessary during sample equilibration. Errors arising from non-constant temperature conditions are prevented by simultaneously saving all of the equilibrated gas samples in separate reservoirs when the equilibration reaction is complete. Several other innovations in sample rack design are also described. These are: a circular rack geometry; an improved, inexpensive, magnetic stirrer design to agitate water samples; a Peltier cooling device to trap water vapour; and the use of standard Pyrex test tubes as equilibration flasks. The preparation line is highly modular. Up to sixteen racks, each capable of preparing sixteen samples, can be included in the system. Racks may be removed, repaired or modified, and replaced, without disturbing the operation of any other racks in the system. The current configuration is a minimum system with only one rack. The programming concepts used to control operation of the system are new to this application, and hence are a significant contribution. A multi-tasking executive allocates resources amongst the racks on a priority basis. By using linked list structures, the operating system maximises resource and processor utilisation, but does not compromise flexibility and modularity. The operator can submit any rack for preparation at any time, and the system could, with sixteen racks, prepare a full load of 256 samples in a day. A simple handshaking interface has been provided to control the release of samples for analysis. This should make it possible to connect the sample line to any mass spectrometer capable of the automated analysis of carbon dioxide. The user controls sample line operation by commands entered on a teletype keyboard. The command language is deliberately unstructured, and users can type in "natural" English sentences if they wish. All system operations and user sentences are printed on the teletype to provide a permanent record for later scrutiny. Finally a manual command repertoire has been provided. It allows the operator complete control over any rack. All solenoids, registers, and control lines, can be manipulated on an individual basis from the teletype keyboard. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

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Thesis (M.S.)--University of Wisconsin--La Crosse, 2002. / Includes bibliographical references.