bubble columns are gas- liquid contactors that are widely used in chemical and bio- chemical industries. high mixing that result in high heat and mass transfer rates are amongst their advantages. heat transfer in a bubble column having a bundle of heaters investigated and the variation of heat transfer coefficient with variation in heaters pitch to diameter ratios in a bundle of heaters reporte...

conclusions in all of the investigated imported rice samples, the level of afb1 and total afs were found to be lower than the iranian mtl, and no health risk for consumers were detected at these levels of contamination. results the results showed that the highest concentration of afb1 and total afs in the rice samples were 2.3500 and 2.7040 ng/g, respectively. the different mean concentration o...

let a; b; k 2 k and u ; v 2 u(k). we show for any idempotent e 2 k, ( a 0 b 0 ) is e-clean i ( a 0 u(vb + ka) 0 ) is e-clean and if ( a 0 b 0 ) is 0-clean, ( ua 0 u(vb + ka) 0 ) is too.

this article deals with the issues associated with developing a new design methodology for the nonlinear model-predictive control (mpc) of a chemical plant. a combination of multiple neural networks is selected and used to model a nonlinear multi-input multi-output (mimo) process with time delays.  an optimization procedure for a neural mpc algorithm based on this model is then developed. the p...

the potential of six economically cheap agricultural waste materials, viz. rice husk, betel nutpeels, sugarcane molasses, tea waste, mustard oil cake and saw dust, was investigated for copper and leadremoval from aqueous solutions under batch and continuous conditions. the effect of ph, contact time,sorbent dose and initial metal ion concentration on the uptake of copper and lead was first exam...

the pomegranate seed oil (pso), containing 17-α-estradiol, is one of the newly found phytosterols with synergistic health effects on estrogen related physiological conditions. herein, pso was assessed for its potential improving effects on bone characteristics in a rat model of menopausal syndrome. three month old non-pregnant female wistar rats (n = 30) were either sham-operated (sham) or ovar...

A column of alumina modified with sodium dodecyl sulfate (SDS) and dimethylglyoxime (DMG) was prepared for the preconcentration of trace nickel from water samples for flame atomic absorption spectrometry (FAAS) determinations. Under optimized conditions (pH=7.0; flow rate: 20 mlmin-1) nickel was retained on the column. The nickel collected on the column was eluted with 5 mL of 1 M nitric ac...

The present study addresses optimal design of reinforced concrete (RC) columns based on equivalent equations considering deformability regulations of ACI318-14 under axial force and uniaxial bending moment. This study contrary to common approaches working with trial and error approach in design, at first presents an exact solution for intensity of longitudinal reinforcement in column section by...

Abstract: In recent years deadly earthquakes in seismic areas have caused special concerns regarding liquefaction phenomenon by researchers and specialists. Excess pore water pressure in loose sediments may cause phenomena such as boiling, shearing strength and dynamic stiffness reduction and lateral movements cause difficulties. Many remedial methods such as soil replacement with proper materi...