Modelling microbial transport in simulated low-grade heap bioleaching systems: The hydrodynamic dispersion model

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.The hydrodynamic model was developed to describe microbial growth kinetics within heap bioleaching systems. Microbial partitioning between the bulk flowing pregnant leach solution (PLS) and ore-associated phases that exist within the low-grade chalcopyrite ore bed, as a function of microbial transport between these identified phases, was investigated. Microbial transport between the bulk flowing PLS and ore-associated phases was postulated to be driven by the microbial concentration gradient between the phases, with advection and dispersion forces facilitating microbial colonisation of, and transport through, the ore bed. The population balance model (PBM) was incorporated into the hydrodynamic model to estimate mineral dissolution rates as a function of available surface area appropriately. Temporal and spatial variations in microbial concentration in the PLS and ore-associated phases are presented together with model predictions for overall ferrous and ferric iron concentrations, which account for iron concentrations in the bulk flowing PLS and that in the vicinity of the mineral surface. The model predictions for PLS and ore-associated microbial concentrations are validated with experimental data, demonstrating the improvement of this model over the previously presented ‘biomass model’. Based on Michaelis-Menten type kinetics, model-predicted true maximum specific growth rates for Acidithiobacillus ferrooxidans in the PLS and ore-associated phases were found to be 0.0004 and 0.019 h −1 , respectively. Estimated microbial attachment and detachment rates suggest that microbial growth is more prolific in the ore-associated phases with subsequent transport to the bulk flowing PLS. Sensitivity analysis of the hydrodynamic transport model to changes in the advection mass transfer coefficient, dispersion coefficient and inoculum size are discussed. For the current reactor configuration, increasing the irrigation rate from 2 to 2.5 L m −2  h −1 , i.e. increasing the advection mass transfer rate, resulted in a significant decrease in microbial retention within the ore bed.The financial assistance of the Department of Science and Technology (DST) and the National Research Foundation (NRF) of South Africa, through the South African Research Chairs Initiative (SARChI UID64778) is hereby acknowledged. Opinions expressed and conclusions arrived, are those of the author and are not necessarily to be attributed to the NRF

Athens by Sound

Architecture is not only that which is built. Architecture is made up of different aspects, both material and immaterial. The atmosphere, the sounds, the smells, the possibility of interaction between human bodies: these all constitute characteristics of space, characteristics that are assuming an increasing importance within architectural research worldwide. Within this field of thought about “Architecture Beyond Building”, we focus on one particular non-material spatial phenomenon that lies ‘beyond the built’: sound. We have created, thus, an interactive sonic map of Athens, which presents, in an unexpected way, fragments of the atmosphere of the city. What would a non-visual map look like? What would it feel like if you wandered within a forest of headphones, playing sounds from different places in Athens? How would it feel if you found yourself in a ‘map’ that only appeared when you walked in it? What would it be like if the map only appeared when you invited one more person to be with you? The Greek pavilion addresses these questions through an atmospheric interactive ‘game’, presenting fragments of sounds and visual sequences of Athens. The visitor recreates the space around him through his own presence and movement. The map appears only where he walks, and/or when he invites one more person to sit next to him. The bodies of the visitors react with one another and with the space itself, creating a dynamic, changing field. This walk in the pavilion takes you “out there”, through invisible Athens. The pavilion brings forth the aspects of architecture that are ‘beyond the material’: the ‘beyond the built’, the almost unreachable, elusive aspects of space, such as sound, non-visual senses, atmosphere. It challenges, thus, the limits of architecture, the limits of what can be mapped and re-located and what cannot. An edited collection by A. Karandinou, C. Achtypi, S. Giamarelos, including texts by: Ιntothepill, Katie Lloyd Thomas, Martin Parker, Panayiotis Tournikiotis, Mark Wigley, Dorian Wiszniewski, Leslie Kavanaugh, Stephen Cairns, Jonathan Hill, Vassilis Ganiatsas, Anastasios Kotsiopoulos, Constance Classen, Stavros Stavrides, Ole Bouman, William Mitchell, Richard Coyne, Neil Spiller, Kas Oosterhuis, Nora Schueler, Zissis Kotionis, Stelarc, Andreas Angelidakis, Aristide Antonas, Slavoj Žižek, Nikolaos Laskaris, Argyris Rokas, Andreas Kourkoulas, John Peponis, Yorgos Ioannou, Yorgos Tzirtzilakis, Konstantinos Vita, Dionyssis Kapsalis, United Visual Artists, Platon Rivellis, and Dimitris Filippidis. Contributors to the Greek National Participation to the 11th International Architecture Exhibition La Biennale di Venezia "Out there. Architecture beyond building" (2008) Organised by: Hellenic Ministry of Culture [yppo.gr] General Directorate of Modern Culture Directorate of Visual Arts Department for the Promotion of Contemporary Art Curators: Anastasia Karandinou Christina Achtypi Stylianos Giamarelos Video works by Intothepill net [intothepill.net] Artists: Yiannis Grigoriadis Yiannis Isidorou Lina Theodorou Sound Recording / Sound Design Dimitris Miyakis [movement.gr] Vangelis Lympouridis Exhibition Graphics / Catalogue Design Company [company-london.com] Design and Implementation of interactive environment 2monochannels [2monochannels.com] Audiovisual and interactive systems design / acoustic design / construction supervision Iraklis Lampropoulos Giorgos Lampropoulos Software programming Vassilis Boukis Electronic subsystem design Michail Kritsotakis Electrical Design Giorgos Satolias Interconnection of interactive elements Vangelis Lympouridis [inter-axions.com] Dimitris Miyakis Light design L+DG lighting architects [lightingdg.com] Thomas Gravanis Christina Frangeti Construction Gavrilos Michalis [gavrilos.gr] Digital printing Polichromo [polichromo.com] Translations Rachel Howard Nikos Masourides Catalogue photographs Intothepill – Internet video platform Catalogue published by futura publications Marketing communication Chryssa Vrouzi Communication associate Katerina Stamidi Photographer Cathy Cunliffe [cathycunliffeΑΤgmail.com] For their financial and material support for the Greek participation at the 11th International Exhibition of Architecture, La Biennale di Venezia, we express our deepest thanks to the sponsors: Alexander S. Onassis Public Benefit Foundation [onassis.gr] Akzonobel [akzonobel.com] Carteco - Architectural Materials & Design [carteco.gr] L+DG Lighting Architects [lightingdg.com] Plaisio [plaisio.gr] Polichromo Advertising Applications [polichromo.com] iGuzzini illuminazione [iguzzini.com] Diathlasis Architectural Lighting [diathlasis.gr

A structural approach to the description and planning of universities

Available from British Library Document Supply Centre- DSC:D32876/80 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Generation of alternative designs in architectural problems using Shape Grammars defined with animation tools - a computer implementation of shape grammars using modelling and animation software

We present a model of generation of alternative designs to selected architectural and spatial configurations of small complexity. Specifically we present a production pipeline of architectural / spatial configurations using the context of animation and time based design tools. Our model consists of time and space design constraints of boundaries / objects affecting a given architectural design, thus producing an alternative solution for every timeframe of the animation cycle. The alternative designs vary from the original according to their temporal and/or spatial distance from the original object on the animation time-line.  The constraints placed upon the objects, used as actuators of Shape Grammars, are defined informally by the user/designer while their influence can vary according to time, speed, location, configuration of the object and/or the constraint itself. However the constraints further function as formal rules for the Shape Grammar creation so that our model tries to predict ahead of time the emergence of alternate designs. The employ of animation tools [shape driven curves, speed and time-line functions,parent child relationships] in the shape generation of our model empowers the user/designer to configure whole sets of shapes and designs interactively and without the need to define every solution independently. Simultaneously, a different, time-focused view of our model describes its use on designs that develop different configurations over time. Thus a duality of our model is established: either the animated schema may be a sum or family of various designs or the animated time-line represents a single design which changes over time. Finally the possibility of an automated analysis of every design is discussed, using Space Syntax diagrams so the designer can quickly evaluate the various spatial configurations produced by a single original

Responsive Architecture: an Integrated Approach for the Future

An integrated approach towards a responsive architecture is presented. This new direction in architecture is based on recent scientific advances and on available technology in materials, telecommunications, electronics and sustainability principles. The integrated responsive architecture is not confined to offices or housing, but may well extend to intelligent neighborhoods and to intelligent cities. The dynamics of these future systems focus on security, comfort and health for the inhabitants

A Broker Architecture for Integrating Data Using a Web Services Environment

The web service protocol stack provides capabilities for loosely integrating software services but does not provide the higher level support needed for rapid evolution. An experimental system is described for integrating the data from autonomous organizations within the UK health service domain. The results of this experiment have confirmed the need for an integration layer on top of the web service stack to provide the required higher level functionality. In this paper, we summarise our progress to date, and highlight several key research issues of general concern to the web services field, which have emerged from our prototype system. These are set in a general context of providing better ways to provide a service-based model to IT users