Measurements were made of the rate of magnetization, and the magnetization of the series of Dy (Co, Ni)2 compounds to investigate the intrinsic magnetic after effect. This effect is demonstrated by the existence of an intrinsic coercivity such that a critical value of applied field, Hc, must be reached before the domain walls can move freely through the material. However there is some movement of domain walls of fields below Hc, and this gives rise to time dependent magnetization. The mechanisms by which the domain walls overcome the energy barrier to their motion at fields below Hc was investigated in pulsed field, and in steady fields. After measuring the critical field and magnetic moments of each sample, the pulsed field magnetometer results were analysed to show that there is a certain temperature above which the mechanism for domain wall motion appears to be that described by Taylor???s thermal activation model. Below that particular temperature, the magnetization rate depends on the reciprocal of the applied field, and an empirical model is suggested. Estimates are made of the number of spines contained in the average wall kink; the wall jump frequency and the energy barrier. A vibrating sample magnetometer was used to study the magnetization of the specimens in steady fields. The results indicate that both the mechanisms described above are in operation, with thermal activation being a possibility at temperatures as low as 4.2K.

Precision cosmology challenges many aspects of fundamental physics. In particular, quasar absorption lines test the assumed constancy of fundamental constants over cosmological time-scales and distances. Until recently, the most reliable technique was the alkali doublet (AD) method where the measured doublet separation probes variations in the fine-structure constant, ???? e2/??c. However, the recently introduced many-multiplet (MM) method provides several advantages, including a demonstrated ???10-fold precision gain. This thesis presents detailed MM analyses of 3 independent Keck/HIRES samples containing 128 absorption systems with 0.2 &gt zabs &gt 3.7. We find 5.6 ?? statistical evidence for a smaller ?? in the absorption clouds: ????/?? = (-0.574 ?? 0.102) x 10-5. All three samples separately yield consistent, significant ????/??. The data marginally prefer constant d??/dt rather than constant ????/??. The two-point correlation function for ?? and the angular distribution of ????/?? give no evidence for spatial variations. We also analyse 21 Keck/HIRES Si iv doublets, obtaining a 3-fold relative precision gain over previous AD studies: ????/?? = (-0.5 ?? 1.3) x 10-5 for 2.0 &gt zabs &gt 3.1. Our statistical evidence for varying ?? requires careful consideration of systematic errors. Modelling demonstrates that atmospheric dispersion is potentially important. However, the quasar spectra suggest a negligible effect on ????/??. Cosmological variation in Mg isotopic abundances may affect ????/?? at zabs &gt 1.8. Galactic observations and theory suggest diminished 25;26Mg abundances in the low metallicity quasar absorbers. Removing 25;26Mg isotopes yields more negative ????/?? values. Overall, known systematic errors can not explain our results. We also constrain variations in y ?? ?? 2gp, comparing H i 21-cm and millimetrewave molecular absorption in 2 systems. Fitting both the H i and molecular lines yields the tightest, most reliable current constraints: ??y/y = (-0.20??0.44)x10-5 and (-0.16??0.54)x10-5 at zabs = 0.2467 and 0.6847 respectively. Possible line-ofsight velocity differences between the H i and molecular absorbing regions dominate these 1 ?? errors. A larger sample of mm/H i comparisons is required to reliably quantify this uncertainty and provide a potentially crucial check on the MM result.

Bibliography: leaves 207-242. / xiii, 242 leaves : ill. (some col.), maps ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Soil and Water, 2000?

xxi, 230 leaves + photos, tables, graphs ; 30 cm / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.1979) from the Dept. of Soil Science, University of Adelaide

Typewritten copy / 1 v. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, 1958

Over the last century, the problem of a viscous flow past a sphere has received on-going attention due to its many engineering applications. These include combustion processes, sediment transport processes and atmospheric flow problems, where the sphere serves as a good model for more general bluff body particles. In these environments, particles may be subjected to both translational and rotational velocities. The objective of this study was to investigate the effect that sphere rotation, about an axis transverse to the freestream flow, has on the characteristics or the vertical wake structure and the forces exerted on the sphere. That was achieved by solving the time-dependant, incompressible Navier Stokes equations, using a highly accurate Fourier Chebyshev spectral collation method.

Thesis (Ph. D.)--University of New South Wales, 1981. / Also available online.

Thesis (Ph.D.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references (ℓ. 150-163)

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2007. / Härtill 6 uppsatser.

Diss. Stockholm : Handelshögsk., 2001.