Universal Behaviour of Metal-Insulator Transitions in the p-SiGe System

Magnetoresistance measurements are presented for a strained p-SiGe quantum well sample where the density is varied through the B=0 metal-insulator transition. The close relationship between this transition, the high field Hall insulator transition and the filling factor $\nu$=3/2 insulating state is demonstrated.Comment: 6 pages, 4 figures. Submitted to EP2DS XIII conference 199

On the thermal broadening of a quantum critical phase transition

The temperature dependence of an integer Quantum Hall effect transition is studied in a sample where the disorder is dominated by short-ranged potential scattering. At low temperatures the results are consistent with a $(T/T_0)^{\kappa}$ scaling behaviour and at higher temperatures by a linear dependence similar to that reported in other material systems. It is shown that the linear behaviour results from thermal broadening produced by the Fermi-Dirac distribution function and that the temperature dependence over the whole range depends only on the scaling parameter T$_0^{\kappa}$

From semiclassical transport to quantum Hall effect under low-field Landau quantization

The crossover from the semiclassical transport to quantum Hall effect is studied by examining a two-dimensional electron system in an AlGaAs/GaAs heterostructure. By probing the magneto-oscillations, it is shown that the semiclassical Shubnikov-de Haas (SdH) formulation can be valid even when the minima of the longitudinal resistivity approach zero. The extension of the applicable range of the SdH theory could be due to the damping effects resulting from disorder and temperature. Moreover, we observed plateau-plateau transition like behavior with such an extension. From our study, it is important to include the positive magnetoresistance to refine the SdH theory.Comment: 11 pages, 5 figure

How to make an entrance: Piranesi comes to Ballarat

"The inside front cover of this publication carries an image of CRCAH's front door, the main gateway to the former Ballarat Gaol. It is a magnificent example of nineteenth century masonry work. The massive bluestone blocks were carved and chiselled into a grand classical edifice, making a fitting southern finale in scale and significance to the great range of buildings on either side of Lydiard Street. The remarkable architectural statement of a confident gold rich city runs from the os­tentatious neo-classical railway station at the northern end past the Art Gallery, the Mining Exchange, the palatial former Post Office (now housing the studios of the university Arts Academy) and on along the facades of banks, hotels, theatres and churches, in a melody of styles from palladian to gothic (with some 20th century intrusions) down to the suitably 'redbrick' buildings of the Ballarat School of Mines. Here the road swings round to the west so the range of prison buildings bookend the whole composition with a dramatic solemn coda " -From forum articl

Microwave radiation induced magneto-oscillations in the longitudinal and transverse resistance of a two dimensional electron gas

We confirm the existance of magneto-resistance oscillations in a microwave-irradiated two-dimensional electron gas, first reported in a series of papers by Zhudov et al. and Mani et al. In our experiments, on a sample with a more moderate mobility, the microwave induced oscillations are observed not only in the longitudinal - but also in the transverse-resistance (Hall resistance). The phase of the oscillations is such that the decrease (increase) in the longitudinal resistance is accompanied by an increase (decrease) in the absolute value of the Hall resistance. We believe that these new results provide valuable new information to better understand the origin of this interesting phenomenon.Comment: Accepted for publication in journal of Solid State Comunication

Mapping Australia felix : maps, myths and mitchell

This investigation into the oeuvre of Thomas Mitchell, the Surveyor-General of New South Wales from 1827 to 1855, intends to reveal the remarkable opus of work he produced and enquire how he achieved it. The feat that won him fame was his discovery of the rich pasturelands and picturesque landscapes in an area that is now western Victoria, which he called Australia Felix. He matched this enthusiastic name with a finely illustrated and densely detailed two-volume journal of his three exploratory journeys - ostensibly to find where the River Darling met the Murray River. Mitchell learnt his trade as a surveyor and mapmaker in Wellington’s army fighting the French in Spain and Portugal, that theatre of the Napoleonic Wars termed the Peninsular War. The objective of this thesis is twofold. The first is the exposition of a rare and remarkable atlas of battlefield plans he was commissioned to survey at the conclusion of the war, a task which took him five years in the field, but was only completed and published 25 years later. There are only two known copies of this immense tome in Australian public libraries. The parallel plan is to relate it to the wealth of imagery with which he illustrated the journal of his expedition in 1836 that discovered Australia Felix. By the artifice of fusing the magnificent maps and landscapes in the atlas with the illustrations in the journals, together with his unpublished artwork, and commissioned structures, a metaphorical map of the new Promised Land can be attempted. Set in a period of revolution and European expansion, it is a study encompassing histories of nationalism, exploration, cartography, colonisation, indigenous relations, warfare, art, and theories of landscape art, architecture, neoclassicism and romanticism, and the aesthetics of the sublime, the beautiful and the picturesque.Doctor of Philosoph

Miners' nystagmus

The increase in the number of certified cases of Ifiners' Nystao-qus and the increase in the duration of disability in a large number of cases have made the condition a question of economic importance. The essential factor in the production of the condition appears beyond doubt to be insufficient illumination. Some improvement has been made in the safety lamps both oil and electric in recent years, but the lighting of most mines is still far from satisfactory.The best method of effecting improvement is the introduction of the electric cap lamp as recommended by the Miners' Nystagmus committee. This it is hoped would soon result in the prevention of Miners' Nystagmus. Failing this the candle power of the hand safety lamps must be increased to at least 3 or 4 c.p.Minor improvements can be effected by white - washing the roadways as far as possible and by providing lamp shields for the journey to the working place.The factor of compensation is responsible for a great deal of the increase in the number of new claims and explains the increased duration of incapacity. Incapacity is, in most cases at least, not due to the actual nystagmus but to neurotic states developing either alone or superimposed upon the nystagmus; and it is this aspect of the disease upon which compensation has had so great an influence.Some alteration in compensation regulations is called for. The duration of compensation may be limited to a definite period, or the rate may be reduced after a certain period. Failing this there should be some machinery for periodic assessment of the capacity or incapacity of cases by medical men with special experience of the disease.In the matter of treatment the important point is to impress the patient that his condition is a benign one, and to persuade him to resume work of some sort at the earliest possible date. Prolonged idleness is the worst possible treatment for these cases.Sympathetic action on the part of the management in providing suitable surface work will be well repaid by results.Errors of refraction should be corrected, and any distressing symptoms such as insomnia should receive suitable therapy

Letter from Samuel Taylor Coleridge to James Augustus Hessey, [1822-25]

Letter from Samuel Taylor Coleridge to his publisher, James Augustus Hessey. The watermark of the paper reads \u27Cowan 1822\u27. The letter discusses the publication of Coleridge\u27s Aids to Reflection in the Formation of a Manly Character, which was first published in 1825. The letter is not published in either The Collected Letters of Samuel Taylor Coleridge or The Unpublished letters of Samuel Taylor Coleridge (both edited by Earl Leslie Griggs). Cf. references to Seneca in the letter to entry no. 5089 in The Notebooks of Samuel Taylor Coleridge (ed. Coburn and Christensen).https://scholarworks.umt.edu/whicker/1018/thumbnail.jp