Gas holdup and bubble size are important parameters for simulation and designing in bubble column reactors. Because based on these parameters, the available gas-liquid interfacial area is defined for mass transfer. In this paper, the results of applying magnetic fields on the velocity field and volume fraction of gas holdup are reported. Hydrodynamics of the bubble column in the reactors is inv...

Reliable estimation of the porous membranes neck-pore size distribution (NPSD) is the key element in the design and operation of all membrane separation processes. In this paper, a new approach is presented for reliable of NPSD of porous membranes using wet flow-state bubble point test data. For this purpose, a robust method based on the linear regularization theory is developed to extract NPSD...

Nucleate boiling heat transfer coefficients may be strongly reduced by scale formation, even for conditions where the bulk foulant concentration is well below the saturation concentration. Due to the mechanism of micro-layer evaporation, the local concentration at the heat transfer surface can be considerably increased, causing the formation of scale and changes in bubble frequency and bubble d...

The bubble effectiveness in liquid phase cylohexane non-catalytic oxidation process is discussed in this paper. Then the bubble effectiveness and a new proposed kinetic model are used in the mathematical model of the industrial reactor for the cyclohexane non-catalytic oxidation process. Furthermore, simulation and optimization based on this reactor model are carried out. The results of sim...

frothers havea profoundeffectonbubble size and also flotation efficiency. in present study the effect of type and dosage of frothers on the flotation response of coarse particles of quartz was investigated.  therefore, flotation response of coarse particles using frothers such as mibc, pine oil, poly propylene glycol with concentration of 0, 25, 50 and 75 g/t, was obtained respectively. for all...

the dry bubble disease, caused by lecanicillium fungicola, is an important fungal disease of white button mushroom in iranian mushroom production farms. twenty-three isolates of the pathogen collected in iran and identified as l. fungicola var. fungicola, were compared for genetic polymorphism, diversity in growth rate and virulence. ten universal rice primers (urp) were used to evaluate the ge...

the bubble effectiveness in liquid phase cylohexane non-catalytic oxidation process is discussed in this paper. then the bubble effectiveness and a new proposed kinetic model are used in the mathematical model of the industrial reactor for the cyclohexane non-catalytic oxidation process. furthermore, simulation and optimization based on this reactor model are carried out. the results of simulat...

The purpose of this study is to investigate and identify the periods of formation and bursting of speculative bubbles in Iran's capital market by creating a state space model and two-mode switching regime (mode 1 is bubble growth and burst stage and mode 2 is the time of bubble loss) during the period from April 2011 to March 2018. The Oxmetrics 7 software is used to investigate the existence o...

Filtration media are required to have suitable pore size, pore size distribution, pore volume, pore surface area and permeability for performing satisfactorily in applications. It is difficult to encounter all the desired properties in a filtration medium. In this investigation, we have characterized filtration media by flow porometry, used these pre-characterized filtration media to design com...