in this research work, the dissolution of chalcopyrite was investigated under atmospheric pressure, with sulfate media at low temperatures, in 30°c to 50°c. in the galvanic interaction between chalcopyrite and pyrite, pyrite is used as a leaching catalyst. effects of different parameters such as temperature, stirring speed, pyrite to chalcopyrite ratio, particle size, and solution potential wer...

a refrigeration cycle is a chain of various pieces of equipment including compressors, condensers, evaporators, and expansion devices each of which takes on a particular thermodynamic process duty in the cycle that eventually results in the production of the required refrigeration. the results of optimized mixed refrigerant cycles (mrcs) in part i show that the configuration of mrc is an effect...

agar is a gelling biopolymer that can be extracted from cell wall of some red algae. in this present, response surface methodology was used to investigate the procedure of agar melting point and gelling temperature from cultural algae of gracilariopsis persica. independent variables, alkalinity concentration (2, 3.2, 5, 6.8, -8%), extraction temperature (90, 96, 105, 114, 120°c) and extraction ...

In the present work, a stainless steel wire was etched by hydrochloric acid during a chemical etching process. The obtained black layer on the surface of the fiber was used as sorbent for extraction of trace amount of phthalates in the aqueous samples by solid phase microextraction. New fiber efficiency was investigated using a home-made solid-phase microextraction (SPME) device and gas chr...

since a long time ago raisins has been considered as an exporting item iniran, in which only 15-20 percent of raisins are consumed and the remaining is exported at a low price. also, until 20 years ago,iranwas one of the most important exporters of raisins to european and asian countries. unfortunately because of retarded technology, lack of modern agricultural methods and also lack of suitable...

In this study, a simple and low-cost method was developed for extraction and pre-concentration of brilliant blue(BB) and Tropaeolin O(TO) in food samples using cloud point extraction (CPE) prior to spectrophotometric determination. The effects of main factors such as pH, surfactant and salt concentrations, incubation time and temperature on the cloud point extraction of both dyes were investiga...

Hill activity (oxygen evolution with ferricyanide as the electron acceptor), light-induced absorbance changes at liquid nitrogen temperature associated with the primary activity of photosystem II, and fluorescence yield changes at both low temperature and room temperature were measured with lyophilized spinach chloroplasts before and after extraction with hexane and reconstitution with beta-car...