An Unknown French Whitmaniac

Describes a seventy-page French pamphlet by a hitherto unknown French writer and journalist known as R. de Maratray

The Earliest French Review of Whitman (Continued)

Contributes to the discourse surrounding the mystery of the nonexistent French translation of Leaves of Grass announced by the New York Saturday Press in 1860 and described in Ezra Greenspan\u27s note also included in this issue of WWQR

My Discovery and Exploration of the Whitman Continent (1941-1991)

Provides an account of the author\u27s involvement in Whitman scholarship, including his early recognition of Whitman\u27s homosexuality and the writing of L\u27 Evolution de Walt Whitman (The Evolution of Walt Whitman)

Whitman on Robert Burns: A Footnote

Adds a footnote to Gary Scharnhorst\u27s essay, "Whitman on Robert Burns: An Early Essay Recovered," by presenting a handwritten note of Whitman\u27s that was incorporated in Whitman\u27s recovered essay on Burns

Geometrical Optimisation of Receivers for Concentrating Solar Thermal Systems

In concentrated solar thermal technologies, the receiver converts concentrated solar radiation into high-temperature heat. Solar receivers are commonly simulated with a stochastic integration method: Monte-Carlo ray-tracing. The optimisation of the geometry of receivers is challenging when using existing optimisation methods for two reasons: each receiver evaluation using Monte-Carlo ray-tracing requires significant computational effort and the outcome of a simulation involves uncertainty. A series of novel optimisation techniques are proposed to enable gradient-free, stochastic and multi-objective optimisation adapted to such problems. These techniques address the computational load difficulty and the challenge of conducting stochastic optimisation based on uncertain evaluations by introducing the concepts of “Progressive Monte-Carlo Evaluation (PMCE)”, “Intermediate Ray Emission Source (IRES)” and adaptive view-factor calculation. A new “Multi-Objective and Evolutionary PMCE Optimisation (MOEPMCE-O)” method is then built around PMCE to enable multi-objective geometrical optimisation of receivers. PMCE is shown to be able to reduce the computational time of a random search optimisation by more than 90% and is used in the geometrical design of a new receiver for the Australian National University SG4 dish concentrator that achieved 97.1% (±2.2%) of thermal efficiency during on-sun testing. MOE-PMCE-O is applied to a multi-objective tower receiver problem where liquid sodium is used as the receiver heat-carrier in a surround configuration heliostat field. A series of useful geometrical concepts emerge from the results, with geometrical features able to maintain high efficiency while keeping acceptable incident peak flux values with a moderate receiver total mass. Finally, a more fundamental look at the impact of the interaction of concentrating optics on the exergy of radiation available at the receiver location highlights the major role played by concentrator surface slope error in lowering the exergy in concentrated solar thermal systems and quantifies the exergy loss associated with non-ideal match between flux and surface temperature in receivers

Geometrical Shape Optimization of a Cavity Receiver Using Coupled Radiative and Hydrodynamic Modeling

AbstractBy using a two-stage optimisation process we maximise the heat rate output of afour-parameter axisymmetric direct steam generation cavity receiver. The model includes radiative and hydrodynamic considerations. We show that a significant range of geometrical shapes show similar efficiencies while having different wall flux and temperature profiles

Control of Epidermal Differentiation by a Retinoid Analogue Unable to Bind to Cytosolic Retinoic Acid-Binding Proteins (CRABP)

The role played by cytosolic retinoic acid-binding proteins (CRABP) in the control of differentiation and morphogenesis by retinoids remains unclear, which contrasts with the presence of these binding proteins in tissues known to be targets for retinoic acid effects. Human epidermis represents a good system to address this question because 1) the effect of retinoids on keratinocyte differentiation is well documented; 2) epidermis contains CRABP, and the amount of these proteins is modulated both by keratinization and retinoids; 3) the architecture of epidermis obtained in vitro by growing adult human keratinocytes on a dermal substrate can be modulated by retinoids added to the culture medium in a dose-dependent manner; and 4) most markers of epidermal differentiation are also modulated by retinoids in a dose-dependent manner.In this study, we compared, in dose-response experiments, the biologic activities of retinoic acid and CD271, a substance unable to bind to CRABP, but able to bind to nuclear retinoic acid receptors (BAR). Our results show that retinoic acid and CD271 exert similar controls on epidermal morphogenesis and keratinocyte differentiation, as shown by the inhibition of the synthesis of suprabasal keratins, filaggrin, and transglutaminase. Therefore, we exclude a qualitative role for CRABP in the control exerted by retinoids on the differentiation and morphogenesis of cultured human keratinocytes. Instead of being involved in the pathway via which retinoids control epidermal gene expression, CRABP might regulate the amount of intracellular-active retinoic acid and thus control quantitatively the intensity of biologic effects

Limits of the cylindrical absorber design for a sodium receiver

The applicability of the cylindrical arrangement of vertical tube banks is evaluated for liquid sodium concentrating solar thermal receivers and compared with a molten salt reference case through a series of parametric studies. It is shown that sodium receivers experience less thermo-elastic stress load and can operate under higher flux which presents advantages in terms of size reduction and efficiency. While the cylindrical receiver configuration cannot reach the efficiency target of 91% in a high temperature configuration (480 °C to 640 °C), there is potential to improve efficiency by improving heliostat field optics. Flux limitations due to thermo-elastic stresses are less stringent due for sodium receivers due to the better heat transfer properties, and consequently better heliostat field optics would benefit sodium receiver concepts more than molten salts ones