University of Johannesburg

About: University of Johannesburg is a education organization based out in Johannesburg, South Africa. It is known for research contribution in the topics: Population & Tourism. The organization has 8070 authors who have published 22749 publications receiving 329408 citations. The organization is also known as: UJ.

Genesis of High-Grade Iron Ores of the Archean Iron Ore Group around Noamundi, India

Abstract: High-grade hematite ores of the Iron Ore Group in the Noamundi area, Jharkhand state, India, are hosted by a laterally extensive, 220-m-thick banded iron formation (BIF) in a folded greenstone belt succession of Paleoarchean age. Single orebodies, which are up to 3 km long along strike and several hundred meters wide, depending on dip of the beds, are strata bound and composed of two major ore types—namely, hard hematite ore that is of ancient geologic origin and ores related to recent weathering along a lateritized Cretaceous-Cenozoic land surface. The ancient hard hematite orebodies comprise laminated hematite ores in which microplaty hematite is dominant, and massive ores composed almost entirely of martite. Supergene ores, in contrast, are comprised of goethite-rich duricrust and soft saprolitic hematite ores representing the leached zone of the Cretaceous-Cenozoic laterite profile. Hard hematite-martite ores formed by hydrothermal replacement of BIF protolith, not only through leaching of silica but possibly also through introduction of iron by hydrothermal fluids of meteoric origin. Hematite iron ore pebbles in a conglomerate at the base of the Meso- to Neoproterozoic Kolhan Group near Noamundi attest to the antiquity of the hard hematite orebodies. Soft saprolitic iron ores formed as a product of lateritic weathering processes in Cretaceous-Cenozoic times. Supergene alteration took place under the influence of reducing and acidic meteoric water, which is typical for lateritic soil profiles developed under humid tropical climatic conditions with lush plant cover. Goethitic duri-crusts capping the laterite profile suggest alternating wet and dry seasons in this environment.

Measurement of the jet fragmentation function and transverse profile in proton-proton collisions at a center-of-mass energy of 7 TeV with the ATLAS detector

Abstract: The jet fragmentation function and transverse profile for jets with 25 GeV < p(Tjet) < 500 GeV and |eta(jet)| < 1.2 produced in proton-proton collisions with a center-of-mass energy of 7 TeV are presented. The measurement is performed using data with an integrated luminosity of 36 pb(-1). Jets are reconstructed and their momentum measured using calorimetric information. The momenta of the charged particle constituents are measured using the tracking system. The distributions corrected for detector effects are compared with various Monte Carlo event generators and generator tunes. Several of these choices show good agreement with the measured fragmentation function. None of these choices reproduce both the transverse profile and fragmentation function over the full kinematic range of the measurement.

A knowledge economy or an information society in Africa? Thintegration and the mobile phone revolution

Abstract: Much has been written about the impacts of new information and communication technology in Africa and its transformational socio-economic impacts. The penetration of mobile phones in particular has been particularly marked in recent years. This paper seeks to interrogate the hypothesis of transformation by examining the ways in which Africa is integrated into the global mobile phone value chain, and then the uses to which this technology is put on the continent. There is a fundamental distinction between having a knowledge economy and an information society. While mobiles are having significant, and sometimes welfare-enhancing impacts, their use is embedded in existing relations of social support, and also conflict. Consequently, their impacts are dialectical, facilitating change, but also reinforcing existing power relations. While Africa may be an information society, it is not, as yet, developing a knowledge economy. Mobile phone usage then represents a form of thin, rather than thick, integration “thintegration” in the global economy, which, because it does not lead to high value-added exports, does not fundamentally alter the continent's dependent position.

Ant assemblages have darker and larger members in cold environments

Abstract: The Mariepskop transect was financially supported by the NRF and 19 Helicopter Squadron at Hoedspruit provided logistical support. T.R.B. was supported by a NERC studentship.