209 research outputs found
Mapping the disaster : global prediction and the medium of ‘digital earth’
No full textThis paper explores the mapping of disaster in digital prediction models. Concentrating on the imminent disaster of climate change, the author asks how global digital models can be expanded to incorporate a wild nature and wild data. This theme is considered through an examination of the ‘nature’ of disaster and its reportage, GISs and their extension into physical space, the language of climate change, and the role of digital machines in these experiments with climate. The author concludes with an examination of expanded forms of mapping to suggest possible reconfigurations of the terms of the disaster
An Interview with Elizabeth Grosz: Geopower, Inhumanism and the Biopolitical
No full text© 2017, © The Author(s) 2017. This article is an interview with Elizabeth Grosz by Kathryn Yusoff and Nigel Clark. It primarily addresses Grosz’s approaches to ‘geopower’, and the discussion encompasses an exploration of her ideas on biopolitics, inhuman forces and material experimentation. Grosz describes geopower as a force that subtends the possibility of politics. The interview is accompanied by a brief contextualizing introduction examining the themes of geophilosophy and the inhumanities in Grosz’s work
An Interview with Elizabeth Povinelli: Geontopower, Biopolitics and the Anthropocene
No full text© 2017, © The Author(s) 2017. This article is an interview with Elizabeth Povinelli, by Mathew Coleman and Kathryn Yusoff. It addresses Povinelli’s approaches to ‘geontologies’ and ‘geontopower’, and the discussion encompasses an exploration of her ideas on biopolitics, her retheorization of power in the current conditions of late liberalism, and the situation of the inhuman within philosophical and anthropological economies. Povinelli describes a mode of power that she calls geontopower, which operates through the governance of Life and Nonlife. The interview is accompanied by a brief contextualizing introduction
Processing, Microstructure And Properties Of In Situ Copper Reinforced Tungsten Carbide Nanostructured Composite
No full textThe present work investigates characteristics and properties of in situ nanostructured copper-tungsten carbide composite prepared by mechanical alloying (MA) and powder metallurgy (PM). Elemental powders of Cu (copper), W (tungsten) and graphite (C) were milled in a planetary ball mill using different ball size, milling time and milling speed. Then the product was compacted at different pressures and sintered at different temperatures and times. In situ tungsten carbide phases (WC and W2C) were only present after a combination of MA and sintering. W2C was first to be observed and the formation of WC began with longer milling times and speeds, in accordance to a decreased crystallite size and an increased of internal strain of Cu during MA. W2C was formed as a result of C deficiency whereas WC through transformation from W2C to WC during sintering
Combustion and Society: A Fire-Centred History of Energy Use
No full textFire is a force that links everyday human activities to some of the most powerful energetic movements of the Earth. Drawing together the energy-centred social theory of Georges Bataille, the fire-centred environmental history of Stephen Pyne, and the work of a number of ‘pyrotechnology’ scholars, the paper proposes that the generalized study of combustion is a key to contextualizing human energetic practices within a broader ‘economy’ of terrestrial and cosmic energy flows. We examine the relatively recent turn towards fossil-fuelled ‘internal combustion’ in the light of a much longer human history of ‘broadcast’ burning of vegetation and of artisanal pyrotechnologies – the use of heat to transform diverse materials. A combustion-centred analysis, it is argued, brings human collective life into closer contact with the geochemical and geologic conditions of earthly existence, while also pointing to the significance of explorative, experimental and even playful dispositions towards energy and matter. © 2014, SAGE Publications. All rights reserved
Effect of Ball Size on Nanostructured Copper-tungsten Carbide Composite Prepared by Mechanical Alloying
No full textIn this study, nanostructured copper tungsten carbide composite was produced by mechanical alloying. Mechanical alloying was carried out by milling of copper (Cu), tungsten (W) and graphite mixture at 40 h with milling speed of 400 rpm in planetary ball mill using two different ball sizes. The crystallite size of the powder milled with 10 mm ball is smaller than 20 mm ball due to higher collision frequency. Lower expansion of Cu lattice was found for the powder milled with 20 mm ball than that of 10 mm ball. The composite obtain by milling with 20 mm ball had produced greater impact energy that facilitated the formation of tungsten carbide (WC)
In Situ Tungsten Carbide Formation in Nanostructured Copper Matrix Composite Using Mechanical Alloying and Sintering
No full textIn this study, an in situ nanostructured copper tungsten carbide composite was synthesized by mechanical alloying (MA) and the powder metallurgy route. The microstructure and phase changes of the composite were characterized by X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy. Tungsten carbide phases (WC and W2C) were only present after MA and combination of sintering. Higher energy associated with a longer milling time was beneficial for the formation of WC. Formation of W2C and WC resulted from internal refinement due to heavy plastic deformation in the composite. The solubility of the phases in the as-milled and sintered composite was described by the changes of the lattice parameter of Cu. Chemical analysis of the surface of a composite of W 4f and C 1s revealed that the increased defects introduced by MA affect the atomic binding of the W-C interaction
In-situ formation of NbC in mechanically alloyed Cu-Nb-C At different temperatures
No full textIn this study, a high-energy ball milling called mechanical alloying was applied to synthesis in- situ copper-based composite reinforced with niobium carbide particle. Cu, Nb and graphite powder mixture were mechanically alloyed for 32 h in a planetary ball with composition of Cu-11.77 %Nb-1.52 %C. The samples of the as-milled powder were compacted at 300 MPa to produce 10 mm diameter pellets. In order to investigate the effect of temperature on the carbide formation, the green compact were sintered in an argon atmosphere at different sintering temperature i.e. 600, 700, 800 and 900 °C. The change of phase and microstructure of the sintered compact were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The result from XRD shows that the NbC phase was not detected at sintering temperatures lower than 900 °C due to not having enough energy to initiate the reaction of Nb and C in Cu matrix. Cu shows an increase in the crystallite size while the internal strain decreases with increasing sintering temperature. The crystallite size of NbC was unresolved since the NbC peak is poorly defined at lower sintering temperature. From EDX analysis, higher oxide content was observed in Cu
Study on the Morphology Stability of TiO2 Nanotube Arrays towards Temperature as a Potential Toxic Gas Sensor
No full textAbstractTiO2 nanotube arrays were prepared by electrochemical anodization of titanium foil in mixed electrolyte solution of NH4F, water, and glycerol. The anodized TiO2 nanotube arrays were calcined at various temperatures and characterized using scanning electron microscope to study the morphology transformation. The results show that at low calcination temperature (300̊C) highly ordered TiO2 nanotube arrays are observed and remained up to 500̊C. At 700̊C, TiO2 nanotube arrays are completely destroyed and transformed to irregular shaped particle
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