Towards an American Postmodernism: Allegory, Appropriation, and Post Studio’s Intervention into Modernism

This project began as an inquiry into the archive of the California Institute of the Arts’ (CalArts) Post Studio Program, whose only relic is a course description written by its founder, artist John Baldessari. An equally important component of this early inquiry was the discovery of Jean-François Lyotard’s palimpsestic text, Pacific Wall, whose frontispiece, “Five Car Stud,” was first publicly displayed at documenta V by artist Edward Kienholz. These two materials led toward a novel articulation of how post studio artistic methodologies – embodied by both Baldessari and Kienholz – intervened in the master narratives of modernism. I argue that the absence of a formal archive of post studio allows for such an intervention. The paucity of materials written on post studio led me to original sources within archives (including the San Francisco Art Institute, Nova Scotia College of Art and Design, and the Getty Research Institute), lending agency to each artist’s voice. By engaging the missing archive of post studio through ventriloquizing its lack, this project deconstructs the normative apparatus of modernism and deromanticizes the sacred space of an artist’s studio. Scholarship generally has understood post studio practice as a methodology eschewing the studio as a space for generating art, its reliance on the political economy of the art market, and its spatialization of sovereign subjectivity. A site of resistance, with aesthetic implications, post studio offers a narrative of its own that defies the artistic conventions of modernism; including, importantly, the authorial legacies, master narratives, and the cult of originalism to which modernism was heavily invested. Informed by French poststructuralism and its debates over postmodernity, I reclaim, posthumously, Craig Owens’s theories on power and representation alongside allegory and appropriation as the key methodologies of post studio artistic practice. These methodologies challenge postmodernity through a heretofore undocumented intervention into modernism.https://digitalmaine.com/academic/1031/thumbnail.jp

Perturbation theory for optical excitations in the one-dimensional extended Peierls--Hubbard model

For the one-dimensional, extended Peierls--Hubbard model we calculate analytically the ground-state energy and the single-particle gap to second order in the Coulomb interaction for a given lattice dimerization. The comparison with numerically exact data from the Density-Matrix Renormalization Group shows that the ground-state energy is quantitatively reliable for Coulomb parameters as large as the band width. The single-particle gap can almost triple from its bare Peierls value before substantial deviations appear. For the calculation of the dominant optical excitations, we follow two approaches. In Wannier theory, we perturb the Wannier exciton states to second order. In two-step perturbation theory, similar in spirit to the GW-BSE approach, we form excitons from dressed electron-hole excitations. We find the Wannier approach to be superior to the two-step perturbation theory. For singlet excitons, Wannier theory is applicable up to Coulomb parameters as large as half band width. For triplet excitons, second-order perturbation theory quickly fails completely.Comment: 32 pages, 12 figures, submtted to JSTA

Size distribution and hygroscopic properties of aerosol particles from dry-season biomass burning in Amazonia

International audienceAerosol particle number size distributions and hygroscopic properties were measured at a pasture site in the southwestern Amazon region (Rondonia). The measurements were performed 11 September-14 November 2002 as part of LBA-SMOCC (Large scale Biosphere atmosphere experiment in Amazonia - SMOke aerosols, Clouds, rainfall and Climate), and cover the later part of the dry season (with heavy biomass burning), a transition period, and the onset of the wet period. Particle number size distributions were measured with a DMPS (Differential Mobility Particle Sizer, 3-850nm) and an APS (Aerodynamic Particle Sizer), extending the distributions up to 3.3 µm in diameter. An H-TDMA (Hygroscopic Tandem Differential Mobility Analyzer) measured the hygroscopic diameter growth factors (Gf) at 90% relative humidity (RH), for particles with dry diameters (dp) between 20-440 nm, and at several occasions RH scans (30-90% RH) were performed for 165nm particles. These data provide the most extensive characterization of Amazonian biomass burning aerosol, with respect to particle number size distributions and hygroscopic properties, presented until now. The evolution of the convective boundary layer over the course of the day causes a distinct diel variation in the aerosol physical properties, which was used to get information about the properties of the aerosol at higher altitudes. The number size distributions averaged over the three defined time periods showed three modes; a nucleation mode with geometrical median diameters (GMD) of ~12 nm, an Aitken mode (GMD=61-92 nm) and an accumulation mode (GMD=128-190 nm). The two larger modes were shifted towards larger GMD with increasing influence from biomass burning. The hygroscopic growth at 90% RH revealed a somewhat external mixture with two groups of particles; here denoted nearly hydrophobic (Gf~1.09 for 100 nm particles) and moderately hygroscopic (Gf~1.26). While the hygroscopic growth factors were surprisingly similar over the periods, the number fraction of particles belonging to each hygroscopic group varied more, with the dry period aerosol being more dominated by nearly hydrophobic particles. As a result the total particle water uptake rose going into the cleaner period. The fraction of moderately hygroscopic particles was consistently larger for particles in the accumulation mode compared to the Aitken mode for all periods. Scanning the H-TDMA over RH (30-90% RH) showed no deliquescence behavior. A parameterization of both Gf(RH) and Gf(dp), is given

Optical excitations of Peierls-Mott insulators with bond disorder

The density-matrix renormalization group (DMRG) is employed to calculate optical properties of the half-filled Hubbard model with nearest-neighbor interactions. In order to model the optical excitations of oligoenes, a Peierls dimerization is included whose strength for the single bonds may fluctuate. Systems with up to 100 electrons are investigated, their wave functions are analyzed, and relevant length-scales for the low-lying optical excitations are identified. The presented approach provides a concise picture for the size dependence of the optical absorption in oligoenes.Comment: 12 pages, 13 figures, submitted to Phys. Rev.

Controlled exposure to diesel exhaust and traffic noise - Effects on oxidative stress and activation in mononuclear blood cells

Particulate air pollution increases risk of cancer and cardiopulmonary disease, partly through oxidative stress. Traffic-related noise increases risk of cardiovascular disease and may cause oxidative stress. In this controlled random sequence study, 18 healthy subjects were exposed for 3h to diesel exhaust (DE) at 276μg/m(3) from a passenger car or filtered air, with co-exposure to traffic noise at 48 or 75dB(A). Gene expression markers of inflammation, (interleukin-8 and tumor necrosis factor), oxidative stress (heme oxygenase (decycling-1)) and DNA repair (8-oxoguanine DNA glycosylase (OGG1)) were unaltered in peripheral blood mononuclear cells (PBMCs). No significant differences in DNA damage levels, measured by the comet assay, were observed after DE exposure, whereas exposure to high noise levels was associated with significantly increased levels of hOGG1-sensitive sites in PBMCs. Urinary levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine were unaltered. In auxiliary ex vivo experiments whole blood was incubated with particles from the exposure chamber for 3h without effects on DNA damage in PBMCs or intracellular reactive oxygen species production and expression of CD11b and CD62L adhesion molecules in leukocyte subtypes

Excited States of Ladder-type Poly-p-phenylene Oligomers

Ground state properties and excited states of ladder-type paraphenylene oligomers are calculated applying semiempirical methods for up to eleven phenylene rings. The results are in qualitative agreement with experimental data. A new scheme to interpret the excited states is developed which reveals the excitonic nature of the excited states. The electron-hole pair of the S1-state has a mean distance of approximately 4 Angstroem.Comment: 24 pages, 21 figure

Diesel soot aging in urban plumes within hours under cold dark and humid conditions

Fresh and aged diesel soot particles have different impacts on climate and human health. While fresh diesel soot particles are highly aspherical and non-hygroscopic, aged particles are spherical and hygroscopic. Aging and its effect on water uptake also controls the dispersion of diesel soot in the atmosphere. Understanding the timescales on which diesel soot ages in the atmosphere is thus important, yet knowledge thereof is lacking. We show that under cold, dark and humid conditions the atmospheric transformation from fresh to aged soot occurs on a timescale of less than five hours. Under dry conditions in the laboratory, diesel soot transformation is much less efficient. While photochemistry drives soot aging, our data show it is not always a limiting factor. Field observations together with aerosol process model simulations show that the rapid ambient diesel soot aging in urban plumes is caused by coupled ammonium nitrate formation and water uptake.Peer reviewe

Excitons in one-dimensional Mott insulators

We employ dynamical density-matrix renormalization group (DDMRG) and field-theory methods to determine the frequency-dependent optical conductivity in one-dimensional extended, half-filled Hubbard models. The field-theory approach is applicable to the regime of `small' Mott gaps which is the most difficult to access by DDMRG. For very large Mott gaps the DDMRG recovers analytical results obtained previously by means of strong-coupling techniques. We focus on exciton formation at energies below the onset of the absorption continuum. As a consequence of spin-charge separation, these Mott-Hubbard excitons are bound states of spinless, charged excitations (`holon-antiholon' pairs). We also determine exciton binding energies and sizes. In contrast to simple band insulators, we observe that excitons exist in the Mott-insulating phase only for a sufficiently strong intersite Coulomb repulsion. Furthermore, our results show that the exciton binding energy and size are not related in a simple way to the strength of the Coulomb interaction.Comment: 15 pages, 6 eps figures, corrected typos in labels of figures 4,5, and

On the determination of a cloud condensation nuclei from satellite : Challenges and possibilities

We use aerosol size distributions measured in the size range from 0.01 to 10+ μm during Transport and Chemical Evolution over the Pacific (TRACE-P) and Aerosol Characterization Experiment-Asia (ACE-Asia), results of chemical analysis, measured/modeled humidity growth, and stratification by air mass types to explore correlations between aerosol optical parameters and aerosol number concentration. Size distributions allow us to integrate aerosol number over any size range expected to be effective cloud condensation nuclei (CCN) and to provide definition of a proxy for CCN (CCNproxy). Because of the internally mixed nature of most accumulation mode aerosol and the relationship between their measured volatility and solubility, this CCNproxy can be linked to the optical properties of these size distributions at ambient conditions. This allows examination of the relationship between CCNproxy and the aerosol spectral radiances detected by satellites. Relative increases in coarse aerosol (e.g., dust) generally add only a few particles to effective CCN but significantly increase the scattering detected by satellite and drive the Angstrom exponent (α) toward zero. This has prompted the use of a so-called aerosol index (AI) on the basis of the product of the aerosol optical depth and the nondimensional α, both of which can be inferred from satellite observations. This approach biases the AI to be closer to scattering values generated by particles in the accumulation mode that dominate particle number and is therefore dominated by sizes commonly effective as CCN. Our measurements demonstrate that AI does not generally relate well to a measured proxy for CCN unless the data are suitably stratified. Multiple layers, complex humidity profiles, dust with very low α mixed with pollution, and size distribution differences in pollution and biomass emissions appear to contribute most to method limitations. However, we demonstrate that these characteristic differences result in predictable influences on AI. These results suggest that inference of CCN from satellites will be challenging, but new satellite and model capabilities could possibly be integrated to improve this retrieval