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...

BACKGROUND Prosthetic replacement of spinal discs is emerging as a treatment option for degenerative disc disease. Posterior dynamic transpedicular stabilization (PDTS) and prosthetic disc nucleus (PDN) devices have been used sporadically in spinal surgery. METHODS This was a prospective study of 13 patients averaging 40.9 years of age with degenerative disc disease who underwent posterior pl...

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 slope difference between the two surfaces is a physical magnitude that needs to be measured in areas such as therapy diagnoses, construction, machinery, geology, geophysics, sports sciences, orthopedics. One of devices used measure inclination wireless inclinometer. inclinometer allows you find surface relative ground. Inclinometers are widely biomedical device, especially field therapy. th...

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...