Potential-pH diagrams are reported for iron and nickel in sulfide containing high salinity geothermal brine at 25 and 250 C. Metal sulfides, as well as dissolved chloride complexes, were considered in deriving the diagrams, and the potential-pH relationships for those equilibria involving dissolved H2S or its anions are plotted for a constant total dissolved sulfide content of 10 ppm. The diagrams are used to analyze the general features of the thermodynamic behavior of iron and nickel in geothermal systems, and to identify processes that might be expected to occur in high temperature sulfide containing brines.
This article analyzes the processes whereby a new ‘penal common sense’ aiming to criminalize poverty and thereby normalize precarious wage labor has incubated in America and is being internationalized, alongside the neoliberal economic ideology which it translates and complements in the realm of ‘justice’. Three operations are distinguished in the transatlantic diffusion of this new doxa on ‘security’: (1) the gestation and dissemination of terms, theses, and measures that converge to penalize social insecurity and its consequences; (2) their borrowing, through a work of adaptation to the national cultural idiom and state tradition, by the officials of the different receiving countries; (3) the ‘academicization’ of the categories of neoliberal understanding by pseudo-social research that serves to legitimize the bolstering of the penal state. Denunciations of ‘urban violence’ and increased surveillance of ‘problem neighborhoods’, curfews and the targeting of petty drug offenders, deregulation and privatization of criminal justice services, ‘prison works’ and ‘zero tolerance’: these mottos, notions, and policies promoted by neoconservative think-tanks in the United States and their British trading posts have spread throughout western Europe where they facilitate the transition from a social welfare to a penal management of the rising social misery. Thus one needs to extend the expression ‘Washington consensus’, commonly used to designate neoliberal measures of ‘structural adjustment’ imposed by the rulers of global finance on debtor nations, to encompass the policing and carceral management of the increased poverty and marginality that are the socio-logical consequence of these economic policies in advanced societies.
Dans cet article, l’auteur explicite son approche de l’ethnographie, de la théorie sociale et de la politique du savoir, à travers un entretien au fil duquel il démêle les liens entre ses travaux sur l’incorporation, la marginalité urbaine et l’État pénal. En retraçant son parcours intellectuel, il porte au jour les connexions pratiques et épistémologiques entre ses principaux projets de recherche, spécifie la contribution du travail de terrain à chacun d’eux, et examine les rôles des intellectuels dans les sociétés avancées à l’ère de l’hégémonie néolibérale. Renvoyant dos à dos l’empirisme de Hume et le cognitivisme néo-kantien, l’auteur défend l’usage de l’ethnographie comme instrument de rupture et de construction, souligne la puissance des compétences incarnées, et plaide pour l’impératif de réflexivité épistémique ainsi que pour la multiplication des genres textuels et des styles d’écriture afin de mieux capturer la douleur et la saveur de l’action. Dans la sphère publique, il argue que la science sociale est en mesure d’agir comme dissolvant de la doxa mais aussi comme phare éclairant les propriétés latentes et les tendances inaperçues des transformations sociales, de sorte à perturber et à élargir le débat civique.
Surface science and catalysis have been combined over the last 15 years to study the hydrogenation of the simplest alkene, ethylene, over late-transition-metal catalysts. Ethylene hydrogenation has been used as a model reaction because it yields only one product while permitting molecular information to be gleaned on an important class of chemical reactions. Enormous progress has been achieved in this field in recent years by the application of reaction rate and surface spectroscopic studies. The role of carbon-containing overlayers covering the surface during reaction has been identified, intermediates present during reaction have been observed and detailed molecular mechanisms for this reaction can be proposed.
Surface crystallography with low-energy electron diffraction (LEED) is shown to be developing fast towards solving more complex and diverse kinds of surfaces. This progress is exemplified here with solved structures in three very diverse categories: (1) metal surface reconstructions with multi-layer relaxations: (2) coadsorption of different molecules on metal surfaces; and (3) incommensurate overlayers of graphite on Pt(111). 21 refs., 4 figs.
Localized orbital bonding analysis (LOBA) was employed to probe the oxidation state in cobalt-bis(diaryldithiolene)-catalyzed proton reduction in nonaqueous media. LOBA calculations provide both the oxidation state and chemically intuitive views of bonding in cobalt-bis(diaryldithiolene) species and therefore allow characterization of the role of the redox non-innocent dithiolene ligand. LOBA results show that the reduction of the monoanion species [1Br](-) is metal-centered and gives a cobalt(II) ion species, [1Br](2-), coordinated to two dianionic ene-1,2-dithiolates. This electronic configuration is in agreement with the solution magnetic moment observed for the analogous salt [1F](2-) (μeff = 2.39 μB). Protonation of [1Br](2-) yields the cobalt(III)-hydride [1Br(CoH)](-) species in which the Co-H bond is computed to be highly covalent (Löwdin populations close to 0.50 on cobalt and hydrogen atoms). Further reduction of [1Br(CoH)](-) forms a more basic cobalt(II)-H intermediate [1Br(CoH)](2-) (S = 0) from which protonation at sulfur gives a S-H bond syn to the Co-H bond. Formation of a cobalt-dihydrogen [1Br(CoH2)](-) intermediate is calculated to occur via a homocoupling (H(•) + H(•) → H2) step with a free energy of activation of 5.9 kcal/mol in solution (via C-PCM approach).
Mice lacking the interleukin 7 receptor (IL-7R) generate α/β T cells at a detectable but greatly reduced rate, but γ/δ T cells are completely absent. The special role of IL-7R signaling in γ/δ T cell development has remained unclear. IL-7Rα−/− mice exhibit a paucity of γ gene rearrangements. This striking observation can be explained by a defect in T cell receptor (TCR)-γ gene rearrangement, a defect in TCR-γ gene transcription leading to death of γ/δ lineage cells, and/or a requirement for IL-7R in commitment of cells to the γ/δ lineage. To determine the role of IL-7R signaling in γ/δ T cell development, we examined transcription of a prerearranged TCR-γ transgene in IL-7Rα−/− mice, as well as the effects of IL-7 on transcription of endogenous, rearranged TCR-γ genes in α/β lineage cells. The results demonstrate that IL-7R–mediated signals are necessary for the normal expression of rearranged TCR-γ genes. Equally significant, the results show that the poor expression of TCR-γ genes in IL-7Rα−/− mice is responsible for the selective deficit in γ/δ cells in these mice, since a high copy TCR-γ transgene exhibited sufficient residual expression in IL-7Rα−/− mice to drive γ/δ cell development. The results indicate that the absence of γ/δ T cells in IL-7Rα−/− mice is due to insufficient TCR-γ gene expression.
