Fluidization represents an important particulate and multiphase operation, featuring dynamic interactions between a continuum fluid and a discrete phase. It is typically realized in a vertical column or pipe. Various fluidization regimes occur, depending on the property of the fluidizing particles, flow rate, and external field force applied. This chapter describes gas–solid fluidization represented by dense-phase fluidized beds and circulating fluidized beds. Fluidization under the gas–liquid–solid flow conditions is also illustrated with the inclusion of its limiting condition of two-phase flows. Basic topics of fluidization include the fluidization regime classification and characteristics, phase-interaction mechanisms in the dense and dilute phase fluidization as well as nanoparticle fluidization, fluidized bed systems, and multiscaled transport phenomena, such as clustering, agglomeration, breakup, and coalescence of dispersed particles or bubbles. For the numerical modeling of fluidization systems, the Eulerian–Eulerian modeling is extensively used and often coupled with the DEM models or kinetic theory models for collision-induced transport in the dispersed phase.

In classical approaches to regime taxonomy, classifying a particular order within a typology of regimes turns on identifying the particular mix of its most important institutions and their associated purposes. Baogang He and Mark Warren’s past work has unsettled this familiar approach through a combination of innovative theorizing and empirical research. In this chapter, they extend their approach to recent arguments that Confucian ideals of meritocracy have been a significant factor driving China’s astonishing economic growth in recent decades. Beyond contesting the claim that China’s current regime is meritocratic, they reject altogether the view that “political meritocracy” is a regime type that can be coherently contrasted with “democracy.” Distinctions between regime types turn on how power is conferred on officeholders, whereas “meritocracy” refers to the qualities that officeholders possess. “Meritocracy” should be understood as an adjectival modifier of the two core regime types, authoritarianism and democracy. He and Warren draw on empirical research to argue that the current Chinese regime is a hybrid form, “authoritarian meritocracy with democratic characteristics,” that has emerged through innovative combinations of institutional forms. In practice, Chinese innovations sacrificed both democratic and meritocratic features of these institutions to the temptations of authoritarian rule.