An experimental approach is proposed to investigate the gas-solid structure in the vicinity of a sparger nozzle in a fluidized bed. The local hydrodynamics were studied under injection velocities ranging between 0 and 100 m/s and three orientations. A fiber-optic probe was used to measure the instantaneous local particle holdup near the tip of the sparger nozzle. Under the investigated conditio...

We develop a new theory of supplier diversification based on buyer risk. When suppliers are subject to the risk of buyer default, buyers may take costly action to signal creditworthiness so as to obtain more favorable terms. But once signaling costs are sunk, buyers sourcing from a single supplier become vulnerable to future holdup. Although ex ante supply base diversification can be effective ...

Prediction of the gas holdup and pressure drop in a horizontal pipe for gas-non-Newtonian liquid flow using Artificial Neural Networks (ANN) methodology have been reported in this paper from the data acquired from our earlier experiment. The ANN prediction is done using Multilayer Perceptrons (MLP) trained with three different algorithms, namely: Backpropagation (BP), Scaled Conjugate gradient ...

The hydrodynamics of an internal-loop airlift reactor was numerically and experimentally characterized. gas holdup, liquid velocity, shear rate, flow pattern volumetric oxygen transfer coefficient (kLa) were evaluated as a function the air velocity medium rheology. Tap water CMC solutions used Newtonian non-Newtonian fluids, respectively. standard  model employed for modeling turbulence, uns...

Lu Han and Muthanna H. Al-Dahhan A gaseous tracer technique and procedures were developed and implemented to measure the axial dispersion of gas phase in a slurry bubble column reactor using air-water-glass beads (100ìm). Residence time distribution curves were obtained by measuring the response of gaseous tracer pulse input. The gas phase axial dispersion coefficient, Dg, was determined from m...

When faced with a regulatory constraint, firms can either comply, bribe the regulator to get around the rule, or lobby the government to relax it. We analyze this choice, and its consequences, in a simple dynamic model. In equilibrium, when the level of development is low, firms are more inclined to bend the rule through bribery but they tend to switch to lobbying when the level of development ...

Abstract The gas-liquid-solid mixing characteristics in slurry bubble column were studied using the CFD-PBM model under different cross section coverage ratios of tubes. research shows that with increase proportion area vertical tube, flow field tends to be stable, liquid phase rate becomes faster, and large-scale circulation strengthens, resulting decrease gas holdup. As increases, distributio...