Uplifted cool gas and heating by mixing in cooling flows

We analyze our earlier three-dimensional hydrodynamical numerical simulation of jet-inflated bubbles in cooling flow clusters, and find that dense gas that was not heated by the jets' activity and that resides around the hot jet-inflated bubbles can be identified as uplifted gas as observed in some clusters.During the build up of the dense gas around the hot bubble, mixing of hot bubble gas with other regions of the intracluster medium(ICM) heats the ICM. The vortices that mix the ICM with the hot bubble gas also excite shock waves, sound waves and turbulence. Sound waves, shocks, turbulence and uplifted gas might be easier to detect than the mixing process and hence attract more attention, but we argue that the contributions of these processes to the heating of the ICM do not add up to the level of contribution of the mixing-heating process.     

Planned Shopping Centres

Planned shopping centres affect the geographical direction of retailing and the nature of retailing in general. As major marketing outlets for national and international chains they are especially attractive to consumers. This paper examines shopping centres in New Zealand and their impact on stand alone retailers and includes a case study of the Queensgate shopping centre in Lower Hutt.     

Object-oriented data modelling for spatial databases

Data modelling is a critical stage of database design. Recent research has focused upon object-oriented data models, which appear more appropriate for certain applications than either the traditional relational model or the entity-relationship approach. The object-oriented approach has proved to be especially fruitful in application areas, such as the design of geographical information systems which have a richly structured knowledge domain and are associated with multimedia databases. This article discusses the key concepts in object-oriented modelling and demonstrates the applicability of an object-oriented design methodology to the design of geographical information systems. In order to show more clearly how this methodology may be applied, the paper considers the specific object-oriented data model IFO. Standard cartographic primitives are represented using IFO, which are then used in the modelling of some standard administrative units in the United Kingdom. The paper concludes by discussing current research issues and directions in this area.     

Comment on ' ... Magmatic Conditions of the Fish Canyon Tuff, Central San Juan Volcanic Field, Colorado ' by Whitney & Stormer (1985)

Magmatic conditi ons inferred from the composition of the FishCanyon Tuff by Whitney &Stormer (J. Petrology, 26, 726–62(1985)) and Stormer & Whitney (Am. Miner. 70, 52–64(1985)) differ from studies of other ash-flow tuff and calderasystems, in that they consider the magma to have been unzonedand to have resided at {small tilde}9 kb pressure just priorto eruption. We find these conclusions unconvincing becauseof incomplete sampling of the Fish Canyon Tuff, alteration ofthe tuff after emplacement, and, in particular, serious limitationsof coupled Fe-Ti oxide and two-feldspar geothermobarometry.