Flux through a hole from a shaken granular medium

We have measured the flux of grains from a hole in the bottom of a shaken container of grains. We find that the peak velocity of the vibration, vmax, controls the flux, i.e., the flux is nearly independent of the frequency and acceleration amplitude for a given value of vmax. The flux decreases with increasing peak velocity and then becomes almost constant for the largest values of vmax. The data at low peak velocity can be quantitatively described by a simple model, but the crossover to nearly constant flux at larger peak velocity suggests a regime in which the granular density near the container bottom is independent of the energy input to the system.Comment: 14 pages, 4 figures. to appear in Physical Review

Enthalpies of formation of rare earths and actinide(III) hydroxides: Their acid-base relationships and estimation of their thermodynamic properties

This paper reviews the literature on rare earth(III) and actinide(III) hydroxide thermodynamics, in particular the determination of their enthalpies of formation at 25{degree}C. The hydroxide unit-cell volumes, lanthanide/actinide ion sizes, and solid-solution stability trends have been correlated with a generalized acid-base strength model for oxides to estimate properties for heterogeneous equilibria that are relevant to nuclear waste modeling and to characterization of potential actinide environmental interactions. Enthalpies of formation and solubility-product constants of actinide(III) hydroxides are estimated

Competing C–Br and C–C Bond Fission Following 1[n(O),π∗(C=O)] Excitation in Bromoacetone: Conformation Dependence of Nonadiabaticity at a Conical Intersection

These experiments investigate the competition between C-C and C-Br bond fission in bromoacetone excited in the (1)[n(O),pi(*)(C=O)] absorption, elucidating the role of molecular conformation in influencing the probability of adiabatically traversing the conical intersection along the C-C fission reaction coordinate. In the first part of the paper, measurement of the photofragment velocity and angular distributions with a crossed laser-molecular beam time-of-flight technique identifies the primary photofragmentation channels at 308 nm. The time-of-flight spectra evidence two dissociation channels, C-Br fission and fission of one of the two C-C bonds, BrH2C-COCH3. The distribution of relative kinetic energies imparted to the C-Br fission and C-C fission fragments show dissociation is not occurring via internal conversion to the ground electronic state and allow us to identify these channels in the closely related systems of bromoacetyl- and bromopropionyl chloride. In the second part of the work we focus on the marked conformation dependence to the branching between C-C fission and C-Br fission. Photofragment angular distribution measurements show that C-Br fission occurs primarily from the minor, anti, conformer, giving a beta of 0.8, so C-C fission must dominate the competition in the gauche conformer. Noting that the dynamics of these two bond fission pathways are expected to be strongly influenced by nonadiabatic recrossing of the reaction barriers, we investigate the possible mechanisms for the conformation dependence of the nonadiabatic recrossing with low-level ab initio electronic structure calculations on the C-Br reaction coordinate and qualitative consideration of the conical intersection along the C-C reaction coordinate. The resulting model proposes that C-C bond fission,cannot compete with C-Br fission in the anti conformer because the dissociation samples regions of the phase space near the conical intersection along the CC fission reaction coordinate, where nonadiabaticity inhibits C-C fission, while from the gauche conformer C-C fission can proceed more adiabatically and dominate C-Br fission. A final experiment confirms that the branching ratio changes with the relative conformer populations in accord with this model

The Politics of Pleasure: Promenading on the Corniche and Beachgoing

Can the pleasures of young Palestinian women from refugee camps in promenading on the Beirut seaside Corniche on a warm summer evening be political? Or days spent at women-only beaches? If so, how do we understand such pleasure as everyday practices, as a politics of the present moment, or conversely (or simultaneously) as mechanisms of being co-opted into a broader apparatus of consumerist ideology and capitalist complacency? Drawing on ethnographic research over 2 years I argue that these moments of pleasure are caesuras in the massive apparatus of power – welded from strands of work, neoliberal practice, nationalist certitudes and political exclusion – which binds these women. These acts of pleasure cannot easily be categorised as ‘resistance’ but I argue that they should not facilely be considered reinforcements of hegemonic control either. They are momentary and ephemeral recognitions of ordinary life lived in hard times, attempts at clawing back an instant of joy from the drudgery of the everyday, and a surrender to the enjoyment of conviviality in public and urban spaces. If they are at all political, they are so because such conviviality is ever harder to sustain in the calamity of hopelessness that characterises so much politics today

Contemporary Art and Transitional Justice in Northern Ireland: The Consolation of Form

Abstract Contemporary artworks in Northern Ireland are explored here as critical constellations, in Walter Benjamin’s sense, that engage the cultural processes of transition through their problematisation of it. It is argued that the artworks become sites in which the assumptions of transition are opened up for critical reflection, requesting attention to the foreclosing of the meanings of memory, of past-and-future, of community. A mode of critical questioning of the present renders the present problematic not in terms of exclusions nor with reference to a past that cannot or will not be erased, but in terms of the present’s inability to be conceived through a linear conception of time. That is, the past and its relation to both the present and to the future are set in oscillation as artworks explore the complex temporalities of a present self-consciously attempting to narrate itself away from the past. The artworks, ‘without the bigotry of conviction’ as Seamus Deane put it, suggest that the task of dealing with the past is flawed wherever the past is conceived as a history that can be rendered present to be judged by subjects who are thereby placed beyond it. That is the illusion of a present ‘no-time’ that dovetails with the desires of commercial enterprise and neo-liberal conceptions of freedom. If this suggests an unceasing restlessness, the consolation is that this questioning does take a form, not as judgement or political decision but as artworks which by definition, remain open to reinterpretation and new understandings. These issues are discussed with reference to the work of four artists in Northern Ireland: the paintings of Rita Duffy, the photography and installation work of Anthony Haughey, and the sculptural works of Philip Napier and Mike Hogg

Possible Observation of the 1/2+ [880] Orbital in 249-Cm

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

Anarchism, individualism and communism: William Morris's critique of anarcho-communism

This collection of essays, showing how the boundaries between Marxism and anarchism have been more porous and fruitful than is conventionally recognised, charts a history of radical socialist collaborations from the late 19th ..

Financial phantasmagoria: corporate image-work in times of crisis

Our purpose in this article is to relate the real movements in the economy during 2008 to the ?image-work? of financial institutions. Over the period January?December 2008 we collected 241 separate advertisements from 61 financial institutions published in the Financial Times. Reading across the ensemble of advertisements for themes and evocative images provides an impression of the financial imaginaries created by these organizations as the global financial crisis unfolded. In using the term ?phantasmagoria? we move beyond its colloquial sense of a set of strange images designed to dazzle towards the more technical connotation used by Ranci�re (2004) who suggested that words and images can offer a trace of an overall determining set-up if they are torn from their obviousness so they become phantasmagoric figures. The key phantasmagoric figure we identify here is that of the financial institution as timeless, immortal and unchanging; a coherent and autonomous entity amongst other actors. This notion of uniqueness belies the commonality of thinking which precipitated the global financial crisis as well as the limited capacity for control of financial institutions in relation to market events. It also functions as a powerful naturalizing force, making it hard to question certain aspects of the recent period of ?capitalism in crisis?