Expected Performance of CryoArray

WIMP-nucleon cross sections below 10^(-9) pb may be probed by ton-scale experiments with low thresholds and background rates ~20 events per year. An array of cryogenic detectors ("CryoArray") could perform well enough to reach this goal. Sufficient discrimination and background suppression of photons has already been demonstrated. Reduction of neutron backgrounds may be achieved by siting the experiment deep enough. Removal of the surface-electron backgrounds alone has not yet been demonstrated, but the reductions required even for this troublesome background are quite modest and appear achieveable.Comment: 4 pages, 2 figures. Talk at DM2002 Conference, Marina del Rey, CA, Feb 20-22, 200

Towards One Tonne Direct WIMP Detectors: Have we got what it takes?

Experimentally have we got what it takes to pursue the direct observation of WIMP interactions down to sensitivities of a few events /100 kg/year? For a Ge target with a low energy threshold (<20 keVr) this corresponds to a WIMP-nucleon sigma~10^-46 cm^2. A number of recent theoretical papers, making calculations in SUSY-based frameworks, show many (>5) orders of magnitude spread in the possible interaction rates for models consistent with existing Cosmology and Accelerator bounds. Some theorists, but certainly not all, are able to generate models, that lead to interaction rates at the few /kg/day that would be implied by the current DAMA annual modulation signal. All theorists demonstrate models that generate much lower interaction rates. This paper takes an unashamed experimentalist`s view of the issues that arise when looking forward to constructing 1 tonne WIMP detectors.Comment: 12 pages (TeX), 6 figures (eps); IDM2000 3rd International Workshop on the Identification of Dark Matter, York, UK, to be published in proceedings Eds. N. J. C. Spooner and V. Kudryavtsev, World Scientific, Singapore, 2001. Slides available at http://www.hep.ucl.ac.uk/~gaitske

Women, religion and medicine in Johannesburg between the wars

African Studies Seminar series. Paper presented 19 August, 1982In explaining the growth of independent churches among the Shona since the 1930s, Daneel lays great stress on the attraction for ordinary members of the curative powers offered by the church. Many joined because they personally or close relatives were cured in faith healing sessions. Unlike churches of outside origin, the African churches took evil forces seriously and combated them in a way appealing to the patient's mind. Diagnostic sessions grappling with the spiritual causes of misfortune seemed to be the key to success. Daneel, like other modern commentators, takes a much more positive view of prophetic therapeutic treatment, seeing it as essentially Christian in character.(1

Race, gender and imperialism: A century of black girls' education in South Africa

African Studies Seminar series. Paper presented August, 198

'Christian compounds for girls': church hostels for African women in Johannesburg, 1907-1970.

African Studies Seminar series. Paper presented August, 1977Compounds in the mining industry gave Rand and Kimberley capitalists a vital means of industrial and police control of their labour force, as well as enabling them “to provide amenities such as recreation and health supervision” (1), no less important for the smooth running of the mines. Local authorities adapted this idea, in open compounds for casual labourers and, as Davenport has noted, 'it was a short step from the municipal compound to the “native hostel”, which became a common feature of municipal locations in the larger centres under the stimulus of the Urban Areas Act of 1923.'(2) This paper examines three hostels for African women which were established in Johannesburg by missionaries of the Anglican and Methodist Churches, and the American Board Mission

Home and Away:: Creating Female Religious space for 20th-Century Anglican missions in southern Africa

Daheim und auswärts. Das schaffen eines weiblichen religiösen Raumes für anglikanische missionen im südlichen Afrika im 20. Jahrhundert Missionarinnen verkörpern das Verhältnis Religion-Gender-Raum, denn sie verlassen den vertrauten Raum „zu Hause“ und bauen in der Fremde neue religiöse und kulturelle weibliche Räume auf, indem sie versuchen, ihr Glauben auf eine gender-spezifische Weise zu verbreiten. Der Aufsatz zeigt am Beispiel von fünf Anglikanerinnen aus Großbritannien, die zwischen 1907 und 1960 im Süd-Transvaal (Südafrika) bzw. in Mozambique missionarisch tätig waren, dass der sakrale Raum, der solchen Frauen zur Verfügung stand, sich in der ersten Hälfte des 20. Jahrhunderts ausdehnte, ab Mitte des Jahrhunderts jedoch eher schrumpfte – teilweise wegen der Einführung von Apartheid, aber auch wegen des Strebens afrikanischer Frauen, sich von der Vormundschaft europäischer Missionarinnen zu befreien. Der Aufsatz zeigt eine raumbezogene Spannung zwischen einer hohen Wertschätzung der „Häuslichkeit“ und einer hohen Mobilität der Missionarinnen sowie der afrikanischen Christinnen, mit denen sie in Beziehung standen

Female Mission Initiatives: Black and White Women in Three Witwatersrand Churches, 1903-1939.

This thesis is a historical study of the religious initiatives taken by two groups of women - white missionaries and African Christians - in the Anglican, Methodist and American Board Mission Churches on the Witwatersrand, South Africa, before the Second World War. It begins by setting the women in context. The nineteenth century background of women and the church is considered first. Then the recruitment of the female missionaries who worked in Johannesburg is examined and the effects of their social origins and training are explored, In the broad characterisation of the African women of Johannesburg which follows, particular stress is laid on the three main spheres of employment open to them, namely domestic service, beer-brewing and laundry work. The second part of the thesis looks at the important prayer unions founded and run by black women, sometimes with missionary help. In all three missions, African women showed great enthusiasm for public prayer and revivalist preaching. Members were also anxious to preserve the premarital chastity of their daughters. Other common concerns were the wearing of uniforms, fund-raising and campaigning for total abstinence from liquor. The individual history of each church association is outlined first, then the emphases which united them are analysed and accounted for. The last part of the thesis concentrates on three particular areas where white female missionaries were active. They set up hostels for servants and provided housewifery training. Sunday schools and a Christian youth movement for girls were frequently under female supervision, Anglican women pioneered two 'settlement houses' in African townships. The class and racial tensions reflected in all three endeavours are highlighted. A brief epilogue sketches the fate of both types of female mission initiatives

Use of digital imaging for gradation and breakage of railway ballast

The foundation of ballasted railway is usually consisted of a graded layer of granular media of ballast placed above naturally deposited subgrade. The ballast layer is responsible for limiting the vertical stress magnitudes applied to the weaker subgrade and also prevents the vertical and lateral train-induced sleeper movements. In recent years, the progressive use of faster and heavier trains has compromised the ability of ballast to resist such movements due to the increased magnitude of ballast breakage (degradation). Therefore, accurate determination of ballast breakage is important. The amount of ballast breakage can be estimated by comparing the gradation (particle size distribution) curves of fresh and degraded ballast, using a ballast breakage index. However, the Australian railway authorities currently rely on the visual inspection for estimating ballast breakage. Despite the fact that the visual inspection is convenient, as it does not require transport of ballast samples or testing, it is subjective and can lead to uneconomical maintenance cycles. In this paper, an attempt is made to utilise the digital imaging technique for gradation analysis and breakage estimation of ballast. The technique is fast and convenient, and can be applied to both the laboratory and field conditions, hence, can be used successfully to replace the visual inspection of ballast breakage