In this study, the diffusivity and volumetric mass transfer coefficients for the extraction of β-carotene from crude palm oil using CO2 solvent in supercritical fluid were determined in the pressure range of 7.5-17.5 MPa and temperature range of 80-120 ºC. For this purpose, a statistical method was applied in order to minimize the number of experiments required. The volumetric ma...

abstract   background: irregular working hours, including night work and shift work, have been found to be associated with alteration in various levels of biochemical factors. and some studies have showed association between shift work and blood biochemical disturbances in blood. in this epidemiological study we investigated, whether regular schedule of working hours can minimize the associated...

After a historical introduction to Poisson’s equation for Newtonian gravity, its analog for static gravitational fields in Einstein’s theory is reviewed. It appears that the pressure contribution to the active mass density in Einstein’s theory might also be noticeable at the Newtonian level. A form of its surprising appearance, first noticed by Richard Chase Tolman, was discussed half a century...

in this study, the diffusivity and volumetric mass transfer coefficients for the extraction of β-carotene from crude palm oil using co2 solvent in supercritical fluid were determined in the pressure range of 7.5-17.5 mpa and temperature range of 80-120 ºc. for this purpose, a statistical method was applied in order to minimize the number of experiments required. the volumetric mass transfer coe...

Joule-Thomson cooling systems are used in refrigeration processes such as cryogenic gas liquefaction. Although extensive studies have been carried out by researchers, most of them include cryogenic heat exchangers and their associated fields. In the current study, an attempt was made to indicate the effect of using inappropriate operational conditions in a cryogenic Joule-Thomson cooling system...