In the social factory? Immaterial labour, precariousness and cultural work

This article introduces a special section concerned with precariousness and cultural work. Its aim is to bring into dialogue three bodies of ideas -- the work of the autonomous Marxist 'Italian laboratory'; activist writings about precariousness and precarity; and the emerging empirical scholarship concerned with the distinctive features of cultural work, at a moment when artists, designers and (new) media workers have taken centre stage as a supposed 'creative class' of model entrepreneurs. The paper is divided into three sections. It starts by introducing the ideas of the autonomous Marxist tradition, highlighting arguments about the autonomy of labour, informational capitalism and the 'factory without walls', as well as key concepts such as multitude and immaterial labour. The impact of these ideas and of Operaismo politics more generally on the precarity movement is then considered in the second section, discussing some of the issues that have animated debate both within and outside this movement, which has often treated cultural workers as exemplifying the experiences of a new 'precariat'. In the third and final section of the paper we turn to the empirical literature about cultural work, pointing to its main features before bringing it into debate with the ideas already discussed. Several points of overlap and critique are elaborated -- focusing in particular on issues of affect, temporality, subjectivity and solidarity

Effects of carbon dioxide attack on geothermal cement grouts

Studies of carbonation of geotheirmal grouts have shown that the physical criteria recommended by the American Petroleum Institute do not apply for durability in CO/sub 2/-containing fluids. The high silica binders, normally considered desirable because of their high strengths and low permeability, become permeable when carbonated. This allows further attack on the grout, and if the fluids are undersaturated with CaCO/sub 3/, then rapid corrosion will occur. On the other hand, grouts which contain appreciable amounts of calcium hydroxide have proved the most durable in CO/sub 2/-containing fluids despite their low strengths and high permeability. This is due to an impermeable layer of calcium carbonate which forms on the outside of the sample preventing further penetration of reactant species. Unless this layer is corroded, no further attack occurs

Characteristics of high temperature cementitious lost-circulation control materials for geothermal wells

Materials systems have been formulated for the in situ conversion of water-based bentonite drilling fluids into cementitious lost-circulation control materials (CLCM) for use in geothermal wells at temperatures up to 300/sup 0/C. The formulations consist of a cement hardener, a borax admixture, and a fiber glass bridging material which are added to the bentonite fluids. Evaluations of the properties of the slurry and the cured CLCMS revealed that the ions supplied by dissociation of the borax in the CLCM slurry acted to suppress the bentonite hydration and retarded the hardening rate of the cement at elevated temperatures. The CaO-SiO/sub 2/-H/sub 2/O (C-S-H) phases formed during curing of the CLCM play essential roles in improving the quality of the hardened CLCMs. It was observed that xonotlite-truscottite transformation resulted in strength reductions and increased water permeability. The plugging ability of fiber glass depends on the conentration and fiber size. The silicate ions dissolved by hot alkaline disintegration of the fiber glass were chemisorbed with Ca/sup 2 +/ ions from the cement and led to the precipitation of C-S-H compounds on the fiber surfaces, which improved bond strength at the matrix-fiber interfaces

Interaction between BaCO3 and OPC/BFS composite cements at 20 degrees C and 60 degrees C

A BaCO3 slurry, containing radioactive C-14, is produced during the reprocessing of spent nuclear fuel. This slurry is encapsulated in a Portland-blastfurnace slag composite cement. The effect of BaCO3 on the hydration of OPC and Portland-blastfurnace slag cements has been studied in this work. Samples containing a simulant BaCO3 slurry were cured for up to 720 days at 20 and 60 degrees C and analysed by XRD. SEM(EDX) and ICC. BaCO3 reacted with OPC to precipitate BaSO4 from a reaction between soluble sulfate and BaCO3. Calcium monocarboaluminate subsequently formed from the carbonate released. The monocarboaluminate precipitated as crystals in voids formed during hydration. At 60 degrees C in OPC, it was not identified by XRD, suggesting the phase is unstable in this system around this temperature. In the Portland-blastfurnace slag cements containing BaCO3, less monocarboaluminate and BaSO4 were formed, but the hydration of BFS was promoted and monocarboaluminate was stable up to 60 degrees C. (C) 2010 Elsevier Ltd. All rights reserved