the main objective of this paper is to examine the effect of nanomaterials on mass transfer coefficient in bubble type absorption of carbon dioxide by experiment. the absorption process is carried out in a bubble column and in room temperature. mass transfer coefficient, saturated concentration of co2, and gas holdup are determined in this system. the kinds of nanomaterials, the concentrations ...

This paper investigates the holdup problem in the dynamic search market where buyers and sellers search for their trading partners and specific investments are made after match but before trade. We show that frictionless (competitive) market imposes severe limitations on attainable efficiencies: Markets with small friction make the holdup problem more serious than those with large friction beca...

In this work, feasibility of flow pattern and oil holdup prediction for vertical upward oil–water two–phase flow using pressure fluctuation signals was experimentally investigated. Water and diesel fuel were selected as immiscible liquids. Oil holdup was measured by Quick Closing Valve (QCV) technique, and five flow patterns were identified using high speed photography through a transparent tes...

In airlift reactors transport phenomena are achieved by pneumatic agitation and circulation occurs in a defined cyclic pattern through a loop. In the present work, the effect of geometrical relations on gas holdup and liquid velocity, and consequently on the gas-liquid mass transfer coefficient, was studied in a 6liter airlift bioreactor with AD/AR = 0.63; AD, downcomer cross-sectional area, an...

A novel multiple-airlifting membrane bioreactor is built with four sintered stainless steel tubular filters as the risers and downcomers. This work investigates the hydrodynamics including gas holdup, liquid velocity, liquid circulation and mixing times by aerating different number of risers (one to three) at superficial gas velocities of 0.02–0.07m/s The mass transfer phenomena, including oxyg...

This paper studies bilateral trade in which the seller makes a hidden investment that influences the buyer’s hidden valuation. In general it is impossible to implement both first-best efficient trade and efficient investment using budgetbalanced trading mechanisms. The paper fully characterizes the constrained efficient contracts. It is shown that the optimal tradeoff between allocative efficie...

Three different aeration plates are used to study their effect on gas holdup and flow regime transition in fiber suspensions. The aeration plates differ by their open-area ratios (A=0.57%, 0.99%, and 2.14%), where the hole diameter remains the same while the number of holes increase. Experiments are performed using three different Rayon fiber lengths (L=3, 6, and 12mm) over a range of superfici...

Multivariable regression and artificial neural network procedures were used to modeling of the input power and gas holdup of flotation. The stepwise nonlinear equations have shown greater accuracy than linear ones where they can predict input power, and gas holdup with the correlation coefficients of 0.79 thereby 0.51 in the linear, and R2=0.88 versus 0.52 in the non linear, respectively. ...

Holdup was measured at various frequencies, amplitudes, continuous and dispersed phase flow rates for binary systems in a pulsed plate column capable of providing samples at various heights. The binary systems was so selected as to cover a wide spectrum of interfacial tensions. Dispersed phase holdup was found to increase with height in a logarithmic fashion at conditions away from the flooding...

The holdup problem arises when parties negotiate to divide the surplus generated by their relationship specific investments. We study this problem in a dynamic model of bargaining and investment which, unlike the stylized static model, allows the parties to continue to invest until they agree on the terms of trade. The investment dynamics overturns the conventional wisdom dramatically. First, t...