University of Port Elizabeth

About: University of Port Elizabeth is a based out in . It is known for research contribution in the topics: Population & Estuary. The organization has 1067 authors who have published 1538 publications receiving 38560 citations. The organization is also known as: UPE & Universiteit van Port Elizabeth.

Stereotype Reduction Workshop

Abstract: In this paper an organizational intervention in intergroup relations, the Stereotype Reduction Workshop, is described. Outlines of the content, group dynamic processes, theoretical underpinnings and impact of the Stereotype Reduction Workshop are presented.

Radicals of γ-rings

Abstract: (Opgedra aan Prof. Hennie Schutte by geleentheid van sy sestigste verjaarsdag.) Abstract In this note we introduce the concept of a special class of Γ-rings. The upper radical property determined by a special class is then called a special radical. We show that the prime radical, Levitzki nil radical and the nil radical are all special radicals. Next we introduce the notion of a strongly prime Γ-ring and show that the class of all strongly prime r-rings is a special class. Furthermore the special radical determined by the class of all strongly prime r-rings contains the prime radical.

Dissolved oxygen characteristics of the gamtoos estuary, south africa

Abstract: The fall and recovery of dissolved oxygen (DO) is documented throughout the Gamtoos Estuary, South Africa during dry conditions and following light and heavy rainfall over a 13-month period from November 1992 to November 1993. Hypoxic conditions generally occurred in the near-bottom waters of the upper estuary. Localized fluctuations in DO levels are related to the natural diurnal fluctuation associated with photosynthesis of aquatic flora. The drop in DO levels following light rainfall is associated with the volume of oxygen-consuming compounds entering the estuary via runoff from adjacent agricultural fields. This hypoxia was short-lived. Following an extreme rainfall event, however, almost immediate hypoxia was recorded throughout the estuary, and DO levels deteriorated for some time thereafter as a result of the substantial input of organic matter into the estuary. The area of hypoxia and recovery was governed by the freshwater input at the tidal head, estuarine hydrometry and hydrodynamics. Tidal pro...

On uniformly strongly prime gamma rings

Abstract: ,f M and AFM C A, MFA C A, then A is an ideal of M,denoted by A < M. Similar notation will be used for ideals of rings. If A < M,the factor .T-rmg M/A is defined in the natural way. If P <\ M, and U, V < M,UFV C P implies E/CPor^CP, then P is called a prime ideal of M. M is aprime F-ring if the zero ideal of M is prime. The following result is proved along thesame lines as the corresponding one for rings.PROPOSITION 1.1. Let M be a F-ring and let P < M. Then the following areequivalent:(a) P is a prime ideal of M ;(b) For all x,y xFMFy £ P, C P implies x £ P or y £ P.Received 15 September 1987Copyright Clearance Centre, Inc. Serial-fee code: 0004-9729/88 SA2.00+0.00.437

Syngenetic Dolomitization and Sulfide Mineralization

Abstract: Excellent stratigraphic control and diagenetic changes make it possible to demonstrate the temporal relationship as well as the process of Pb-Zn mineralization in well exposed Precambrian rocks of Helikian age on northern Baffin Island, N. W. T., Canada. Initial deposition of shallow-marine, cratonal sediments was interrupted by regional tilting. Emerging areas were extensively karsted and brecciated, affecting in particular laminated algal carbonates. Subsequent subsidence led to the development of a topographically restricted marine environment and in turn to evaporative conditions. The brecciated carbonate and the extensive subsurface channel system which was formed during the preceding episode of karsting, provided perfect passageways for a refluxing dolomitizing brine. Steady-flow conditions and a continuous supply of seawater resulted in the complete dolomitization of the brecciated and channelled hostrock. Seawater must have contributed most if not all the Mg during dolomitization. Continuous circulation of a seawater brine must have introduced other metal ions as well, which were most likely carried as chloride complexes. These combined with a possibly seasonal supply of sulfide ions generated by sulfate-reducing bacteria. Precipitation of Pb and Zn sulfides took place in open fractures (disseminated occurrences) and in channelways (massive occurrences). Karsting, dolomitization and sulfide mineralization were terminated prior to the deposition of another Helikian sequence of clastics and carbonates which are only partially dolomitized and carry no Pb and Zn sulfides.