A multiple scales approach to evaporation induced Marangoni convection

This paper considers the stability of thin liquid layers of binary mixtures of a volatile (solvent) species and a non-volatile (polymer) species. Evaporation leads to a depletion of the solvent near the liquid surface. If surface tension increases for lower solvent concentrations, sufficiently strong compositional gradients can lead to Bénard-Marangoni-type convection that is similar to the kind which is observed in films that are heated from below. The onset of the instability is investigated by a linear stability analysis. Due to evaporation, the base state is time dependent, thus leading to a non-autonomous linearised system, which impedes the use of normal modes. However, the time scale for the solvent loss due to evaporation is typically long compared to the diffusive time scale, so a systematic multiple scales expansion can be sought for a finite dimensional approximation of the linearised problem. This is determined to leading and to next order. The corrections indicate that sufficient separation of the top eigenvalue from the remaining spectrum is required for the validity of the expansions, but not the magnitude of the eigenvalues themselves. The approximations are applied to analyse experiments by Bassou and Rharbi with polystyrene/toluene mixtures [Langmuir 2009 (25) 624–632]

A Calculus of Bounded Capacities

Resource control has attracted increasing interest in foundational research on distributed systems. This paper focuses on space control and develops an analysis of space usage in the context of an ambient-like calculus with bounded capacities and weighed processes, where migration and activation require space. A type system complements the dynamics of the calculus by providing static guarantees that the intended capacity bounds are preserved throughout the computation

The role of investment, fundamental Q and financing frictions in agricultural investment decisions: an analysis pre and post financial crisis

JEL classifcation: G31, G32, F34This paper uses a fundamental Q model of investment to consider the role played by nancing frictions in agricultural investment decisions, controlling econometrically for censoring, heterogeneity and errors-in-variables. Our ndings suggest that farmer's in- vestment decisions are not driven by market fundamentals. We nd some evidence that debt overhang restricts investment but investment is not dependent on liquidity or internal funds. The role of nancing frictions in determining investment decisions changes in the post- nancial crisis period when debt overhang becomes a signi cant impediment to farm investment. The evidence suggests that farmers increasingly rely on internal liquidity to drive investment. Finally, we nd no evidence that farmers use o -farm capital to fund on-farm investment.Teagasc Walsh Fellowship Programm

Study of spectral moments in semileptonic decays of the b hadron with the DELPHI detector at LEP

The measurement of the moments of hadronic mass spectrum and of lepton energy spectrum based on a sample of semileptonic decays of the b hadron selected from $Z^0 \to b \bar b$ events recorded with the DELPHI detector at LEP, are presented. These results are interpreted in terms of constraints on the quark masses and on the b-quark kinetic energy value.Comment: Presented at the XXXI Conference on High Energy Physics Amsterdam, July 200

Role of heat generation and thermal diffusion during frontal photopolymerization

Frontal photopolymerization (FPP) is a rapid and versatile solidification process that can be used to fabricate complex three-dimensional structures by selectively exposing a photosensitive monomer-rich bath to light. A characteristic feature of FPP is the appearance of a sharp polymerization front that propagates into the bath as a planar traveling wave. In this paper, we introduce a theoretical model to determine how heat generation during photopolymerization influences the kinetics of wave propagation as well as the monomer-to-polymer conversion profile, both of which are relevant for FPP applications and experimentally measurable. When thermal diffusion is sufficiently fast relative to the rate of polymerization, the system evolves as if it were isothermal. However, when thermal diffusion is slow, a thermal wavefront develops and propagates at the same rate as the polymerization front. This leads to an accumulation of heat behind the polymerization front which can result in a significant sharpening of the conversion profile and acceleration of the growth of the solid. Our results also suggest that a novel way to tailor the dynamics of FPP is by imposing a temperature gradient along the growth directio

The role of fundamental Q and financing frictions in agricultural investment decisions: an analysis pre and post financial crisis

This paper uses a fundamental Q model of investment to consider the role played by financing frictions in agricultural investment decisions, controlling econometrically for censoring, heterogeneity and errors-in-variables. Our findings suggest that farmer's investment decisions are not driven by market fundamentals. We find some evidence that debt overhang restricts investment but investment is not dependent on liquidity or internal funds. The role of financing frictions in determining investment decisions changes in the post-financial crisis period when debt overhang becomes a significant impediment to farm investment. The evidence suggests that farmers increasingly rely on internal liquidity to drive investment. Finally, we find no evidence that farmers use off-farm capital to fund on-farm investment.Credit Constraints, Firm Level Investment, Tobin's Q, Debt

Determinants of Iowa Cropland Cash Rental Rates: Testing Ricardian Rent Theory

Based on the Ricardian rent theory, this study employs the variable profit function to analyze the determinants of Iowa cropland cash rental rates using county-level panel data from 1987 to 2005. Accounting for spatial and temporal autocorrelations, responses of local cash rental rates to changes in output prices and other exogenous variables are estimated. We find that Iowa cash rental rates are largely determined by output/input prices, soil quality, relative location, and other county-specific factors. Cash rents go up by $79 for a$1 increase in corn price in the short run. The marginal value of cropland quality, as represented by row-crop corn suitability rating index, is about $1.05. Ethanol plants are not found to have a significant local effect on cash rental rates, impacting local rental markets mainly through the national futures price. Scale of the local livestock industry and adoption of genetically engineered crops have significant impacts on local cash rental rates. In addition, changes in crop output prices are found to have long-run effects on cash rental rates. The long-run change in cash rents is approximately$109-$114 for a$1 change in corn price and is reached in about four years. Our research may be viewed as a test of the Ricardian rent theory. We find limited support for the theory.Land Economics/Use,

Homosexuality is a Poem: How Gay Poets Remodeled the Lyric, Community and the Ideology of Sex to Theorize a Gay Poetic

SourceURL:file://localhost/Users/christopherhennessy/Desktop/DISS/Dissertation_Hennessy._Final.doc This dissertation approaches the work of three canonical post-war gay poets in an effort to construct a discourse on sexuality and the minoritized writer that argues the lyric functions as a historically contingent, politically invested, value-laden genre in which some subjectivities might be prohibited from or find their expression made to signify in ways that re-inscribe oppression. The first chapter theorizes the possiblitites of a gay poetic and analyzes the gay poet’s subjectivity as one obsessed with the ways in which he is marginalized due to expression. In the chapter on Frank O’Hara, the poet is shown to disfigure the lyric through the unliterary to allow it to speak for the perverse. In the chapter on Jack Spicer, the poet’s concept of ‘we alone’ is shown to outmaneuver subjugating identificatory structures. The chapter on John Wieners shows how his queer failure frustrates the normative lyric’s reception to produce the very marginalizing the gay writer must resist. The final chapter analyzes the poetry published in the years following the beginning of “gay liberation” (1969-1973) and suggests some poets relied on lyric expressivity in their work; others sought to fashion a poetics that married graphic content with radical experimentation and thus produced a more politically and poetically complex liberationist text