Characterisation of focused ion beam nanostructures by transmission electron microscopy

Ion irradiation is an effective tool for the modifcation and control of the properties of magnetic thin films. Basic magnetic properties such as coercivity and local anisotropy direction can be altered in NiFe (Permalloy) films, whilst for Co/Pd multilayers, ion irradiation results in a transition from perpendicular to in-plane magnetisation. This ability to tailor magnetic properties in a controlled manner can be used as a tool for nanoscale patterning. Results are presented from investigations into the effect of Ga+ ion dose on the magnetic and structural properties of permalloy thin film systems. Systems consisting of a permalloy layer of either 10nm or 20nm, and one or more non-magnetic layers of Al or Au were deposited by thermal evaporation and irradiated in a focused ion beam (FIB) with a 30kV Ga ion source. The presence of the non-magnetic layers allows irradiation induced mixing with the magnetic layer, effectively creating alloyed regions with different properties to the rest of the film. At low ion doses, no signifcant effect on either the magnetic or structural properties were observed. Bright field TEM images of the irradiated regions revealed that increasing the dose to 1x10^15 ions/cm^2 and above caused an increase in mean grain size from ~5nm to ~30nm. The Fresnel mode of Lorentz microscopy revealed that a reduction in the mean moment was also observed at these doses but no clear changes in coercivity or magnetisation reversal behaviour were observed until the systems were rendered non-magnetic. This occurred at 1x10^16 and 3x10^16 ions/cm^2 for systems with 10nm NiFe and 20nm NiFe respectively. Milling of the samples was evident at these high doses, meaning that it was not possible to magnetically pattern these systems without occasioning a change of 2nm and 6nm respectively in the thickness of the samples. Based on the above, structures were created to control the location of magnetic domain walls (DW). Lines were written by FIB in simple elements with dimensions <1micron, the aim being to create a higher density of DW than could be realised in equivalent homogeneous elements. Structures containing high DW densities are attractive for measuring domain wall magnetoresistive effects and have potential application in DW-based storage or logic devices. One geometry of interest is an element with `zigzag' edges. Results are be presented in chapter 4 showing how these can support either quasi-uniform magnetisation or multi-domain structures separated by DW with spacing <100nm. In chapter 5 irradiation of magnetic structures was again carried out, but this time in magnetic wires to create defect or pinning sites. Domain wall traps fabricated by ion irradiation were characterised, and irradiation line defects introduced along the wire. The lines were patterned at 90± and 45± to the length of the wire, and successfully pinned the domain walls at predefned locations. A 90 degree line irradiated at a dose of 1x10^15 ions/cm^2 was not able to provide a strong enough pinning site for a domain wall. However, when the angle of the line was changed to ±45 degrees it was possible to reproducibly pin domain walls at these sites. A relationship between the orientation of the irradiated line and the chirality of the domain wall that pinned at the site was observed. The effcts of irradiation on Co/Pd multilayers with perpendicular magnetic anisotropy was investigated in chapter 6. Irradiation causes magnetic systems with perpendicular magnetisation to undergo a transition from out-of-plane magnetisation to in-plane. A grid pattern was devised so that magnetic states with both in-plane and out-of-plane magnetisation could be observed. A combination of differential phase contrast microscopy and simulations of integrated magnetic induction were used to determine the orientation of magnetisation within the lines

Meta-analyses and adaptive group sequential designs in the clinical development process

Meta-analyses and adaptive group sequential designs in the clinical development proces

Adaptive and non-adaptive group sequential tests

Adaptive and non-adaptive group sequential test

Catholics in a changing Scotland: the Archdiocese of St Andrews and Edinburgh, 1878-1965

Between 1878 and 1965, the Catholic Church in Scotland changed from a small, reclusive and relatively unassertive community to become a force to be reckoned with in social and political terms. The thesis (the first to be based on a thorough examination of the episcopal correspondence of St Andrews and Edinburgh 1878-1965 held in the Scottish Catholic Archives, Edinburgh), argues that this change was caused by the combination of two momentous but unexpected and unconnected events in the 1850s and after — first, the arrival in Scotland of large numbers of economic migrants from Ireland (most of them Catholics) and second, the conversion (through the influence of John Henry Newman) of influential members of the Scottish aristocracy. The former were mainly confined to what is today the geographically small but very densely populated province of Glasgow, the latter, to the geographically more extensive province of St Andrews and Edinburgh, where Irish migrants, much fewer in numbers, integrated more successfully. While Irish migration has been extensively studied by scholars, the conversion of the aristocracy has, with some notable exceptions, remained unappreciated. The thesis contends that it was principally the simultaneous impact of these two phenomena which accounted for the development of the Catholic community in modern Scotland; that it was not only the critical mass of migrants which gave the Catholic Church political leverage but also the networking skills and the funds ofthe convert elites. Other changes in the Catholic Church were subsumed into this larger picture: the role of the clergy was transformed from a pastoral one in 1886 to a combative one in the 1930s and 1940s, while at the same time shifting vis-a-vis the laity (who were themselves moving from subjugation to co-responsibility). The thesis, however, deals not only with the secular clergy but also with the activities of religious orders — the important national provincial Council of Fort Augustus (1886), for example, and the consecration in 1929 of the dynamic Benedictine Abbot Andrew J. McDonald as Archbishop of St Andrews and Edinburgh. By 1918, the virtual collapse of the Catholic school system played into the hands of the government; the resulting financial compromise was mutually beneficial but its price (while it affirmed the Catholic community by providing the educational tools for better employment opportunities), was the loss of autonomy and control. After a series of financial scandals in the 1880s and other examples of mismanagement in the first two decades of the twentieth century, episcopal and parish finances gradually recovered as stricter safeguards were imposed. Between the first and second Vatican Councils a sea-change is visible, not only in the relationship between pope and bishop but also between clergy and laity. The pressure of social and political events 11 gradually transformed the hierarchical pyramid that was the Catholic Church of 1878 into the more egalitarian model of the People of God as embraced in 1965 by the Second Vatican Council

Horizontal studies of cell mediated immune reactions to autologous tumour antigens in patients with operable mammary carcinoma.

The leucocyte migration and guinea-pig macrophage migration procedures were used to assess cell mediated, tumour directed immune reactions in patients with mammary carcinoma undergoing simple mastectomy with or without post-operative irradiation. Forty-seven per cent of patients reacted to autologous tumour antigens and 40% to allogeneic antigens when tested 7 days after operation; 23% reacted to autologous antigens at 2 months, 19% at 6 months and 34% at 1 year after surgery. Reactions to benign tissue fractions were rare. Better discrimination between test and control subjects was obtained when 3000 g sediments rather than nuclei-depleted homogenates (extracts) were used. Irradiation 3-7 weeks post-operatively did not depress the in vitro response at 2 months and yielded a higher rate of positive reactions at 6 months. Correlations of serial LMT responses with certain clinical findings are discussed

Involving Students in the Planning Process

This is the publisher's version, also found at http://sped.org

Nonparametric Estimation of ROC Curves Based on Bayesian Models When the True Disease State is Unknown

Nonparametric Estimation of ROC Curves Based on Bayesian Models When the True Disease State is Unknow