varieties of st. john’s wort (hypericum perforatum l.) native to iran possess the largest percentage of hypercin in their leaves and flowers. isotherm curves show the relationship between the relative humidity and moisture content of the plant at a constant temperature. it is essential to understand the isotherms curves for successful storage and drying of the plant. this study used adsorption ...

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...

gaz-angubin is a sweet exudate naturally produced by an insect from the gavan-e-gaz-angubin plant. adsorption and desorption isotherms for a gaz-angubin sample were determined at 15° and 25°c over a range of relative humidity from 0 to 90% using a dynamic vapor sorption system. at different levels of relative humidity, changes in sample mass were continuously measured versus time and described ...

moisture sorption isotherms for pistachio powder were determined by gravimetric method according to cost 90 project at temperatures of 15, 25, 35, and 40oc . maximum hysteresis level in sorption isotherms curve was observed at the range of water activity 0.2-0.7 . on the other hand hysteresis was diminished between adsorption-desorption isotherm curves when temperature reached 40oc. some mathem...

In previous papers, we have described a suitable method to obtain pore size distributions for voids and necks using the Dual Site-Bond Model (DSBM) and Monte Carlo simulations. This method basically consists in the determination of the corresponding size distributions by using adsorption–desorption hysteresis data. Void size frequency functions are featured from the ascending curve. From the de...

The reversíbilíty of the adsorption of phosphate on goethite was measured by dlluting suspensions of goethite on which phosphate was adsorbed with large volumes oí phosphate-frce solution at the same ioníe strength. The effect on the reversibility of various adsorptíon and desorption conditions was studied, particularly pH, temperature, ionic strength and time of reaction. The apparent irrevers...