Stefan George (1868–1933) was one of the most important and influential poets to have written in German. His work, in its originality and impact, easily ranks with that of Goethe, Holderlin, or ...Rilke. Yet George's reach extended far beyond the sphere of literature. Particularly during his last three decades, George gathered around himself a group of men who subscribed to his homoerotic and idiosyncratic vision of life and sought to transform that vision into reality. George considered his circle to be the embodiment and defender of the real but secret Germany, opposed to the false values of contemporary bourgeois society. Some of his disciples, friends, and admirers were themselves historians, philosophers, and poets. Their works profoundly affected the intellectual and cultural attitudes of Germany's elite during the critical postwar years of the Weimar Republic. Essentially conservative in temperament and outlook, George and his circle occupy a central, but problematic, place in the rise of proto-fascism in Germany. Their own surrogate state offered a miniature model of a future German state: enthusiastic followers submitting themselves without question to the figure and will of a charismatic leader believed to be in possession of mysterious, even quasi-divine, powers. When he died several months after the Nazi takeover, George was one of the most famous and revered figures in Germany. Today the importance of George and his circle has largely been forgotten. In this, the first full biography of George to appear in any language, Robert E. Norton traces the poet's life and rise to fame.
Drawing on recent scholarship on the history of Western esotericism and religious studies on the importance of millenarian thought in Early Modern Europe, this study provides an innovative ...re-examination of Peter the Great's Court in early eighteenth-century Russia.
The number of molecules used in a typical Molecular Dynamics (MD) simulations is orders of magnitude lower than in the thermodynamic limit. It is therefore essential to correct diffusivities computed ...from Molecular Dynamics simulations for finite-size effects. We present a comprehensive review on finite-size effects of diffusion coefficients by considering self-, Maxwell-Stefan, and Fick diffusion coefficients in pure liquids, as well as binary, ternary, and quaternary mixtures. All finite-size corrections, both analytical and empirical, are discussed in detail. The finite-size effects of rotational and confined diffusion are also briefly discussed.
The efficient numerical solution of the one‐phase linear inverse Stefan and Cauchy–Stefan problems is a delicate task owing to the problems' susceptibility to the perturbation of the given data. In ...this context, heuristic a posteriori error indicators are constructed for such inverse problems with noisy data in two dimensions (2D). Given a fixed computational effort, the estimator controls the error due to discretization by the method of fundamental solution (MFS). It is accomplished through two mean‐driven double‐filtering algorithms. Numerical results substantiate the effectiveness of the algorithms.
•Numerical study on flow and heat transfer of SCW flow around particle pair with Stefan flow.•The fluid-particle interactions with different particle pair configurations under the Stefan flow.•The ...analysis of flow field, force, and heat transfer process around particles.
For any flow process of mixtures containing dispersed reactive particles, especially highly concentrated particles, the particle-particle, and fluid-particle interactions are very complex and affect the overall flow. Supercritical water gasification technology is a complex multiphase-flow process that occurs in high-temperature reactors. Under these conditions, the components of the particle surface are heated and gasify to form a Stefan flow (i.e., a mass flow), which modifies fluid-particle interactions. The interaction between particles and the influence of Stefan flow cannot be ignored. In this work, we consider the simplest case of two identical spherical particles with different relative orientations and particle distances and discuss the flow and fluid-particle heat-transfer characteristics by numerical simulation of supercritical water flowing around the fixed two-particle system. We are particularly interested in the fluid-particle interactions with different particle configurations under the influence of Stefan flow. Three particle configurations are possible: tandem, cross, and parallel. The flow field, Nusselt number, drag coefficient, and temperature distribution around the particles are all analyzed. In comparison with a single particle, the two-particle configurations significantly affect the drag coefficient, Nusselt number, and vortex structure and Stefan flow strongly affects the wake vortex structure of two particles with small particle distance, reducing the drag coefficient and Nusselt number.
In the current study, free convection heat transfer of a suspension of Nano–Encapsulated Phase Change Materials (NEPCMs) is simulated and discussed in an inclined porous cavity. The phase change ...materials are capsulated in nano-shells layers, while the core stores/releases large amounts of energy during melting/solidification in the vicinity of the hot/cold walls. The governing equations are introduced and transformed into non–dimensional form before being solved by using the finite element method. Simulation results are validated thoroughly. Thereafter, the consequences of the fusion temperature and the Stefan number on the distributions of streamlines, isotherms, and the heat capacity ratio, as well as the heat transfer characteristics, are analyzed for different inclination angles of the cavity. Inspection of the results demonstrates that the best heat transfer performance occurs for the non–dimensional fusion temperature of 0.5 and the inclination angle of 42°. It is found that a decrease in the Stefan number improves heat transfer. The results also show that the presence of the NEPCM particles generally leads to heat transfer improvement.
•Heat transfer of nano–encapsulated phase change materials (NEPCMs) is addressed.•The porous cavity is filled with a suspension of NEPCM particles.•The finite element method is employed to solve the phase change governing equations.•The effect of fusion temperature on the thermal behaviour of the cavity is examined.•Using NEPCM particles could enhance the heat transfer up to 28%.
•A particle-scale numerical model for char gasification in CO2/O2/H2O was developed.•The reaction properties of the different positions of the particle were discussed.•Stefan flow has a significant ...effect on the gas components around the particle.•The particle surface temperature increases when particle diameter decreases.•The effects of the ash layer is mainly reflected in the convective heat transfer.
CO2 gasification of biomass provides a new approach to the resourceful solidification and utilization of CO2. The level of char conversion is critical to the overall efficiency of the gasification process. The aim of this numerical study was to investigate the external multifactorial effect of char conversion in a hot CO2/O2/H2O atmosphere at the particle scale with considering the effects of particle size and ash layer. The results demonstrated that increasing inlet temperature promotes gasification mainly by convective heat transfer between the gas stream and the particle surface. This effect diminishes as the inlet temperature increases. The promotion by enhanced convection is mainly due to the thinner boundary layer at the head of the particle, which allows for enhanced heat and mass transfer processes. The gasification process is susceptible to changes in O2 concentration. Despite the fivefold increase in H2O mole fraction (0.1 % ∼ 0.5 %), the gasification process was not significantly accelerated. The influence of Stefan flow on the gasification process is mainly reflected in the rate distribution of the homogeneous reactions. When considering the ash layer cover, the temperature of the particle surface is affected by multiple effects of the increased specific surface area of the char core and convective heat transfer.
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