Metal contamination is one of the most serious global problems. This investigation deals with use Aksaray pumice for adsorption cobalt ions. The factors affecting on were examined. Pumice activated at 873 K two hours before contact UV-Vis spectrophotometer was used to measure ions concentrations. response surface methodology utilized evolve predictive model pumice. experimental and predicted ma...

background: a prolonged life of fissure sealant has always been the target for preventing caries in vulnerable newly erupted teeth. the use of preparatory techniques including bur introduction to the fissures is considered among such improving steps. the aim of this investigation was to compare the microleakage level of fissure sealants prepared by a fissurotomy bur or pumice prophylaxis prior ...

in this work, removal of c. i. acid red 14 was investigated by pumice stone as a low cost adsorbent. various parameters such as initial dye solution, contact time and ph were studied. removal of dye were increased by increasing of contact time and initial dye solution and deceased by increasing of ph. three isotherm models were studied. linear and non-linear regression analyses were used for de...

STATEMENT OF THE PROBLEM Demineralization of enamel adjacent to orthodontic appliances frequently occurs, commonly due to insufficient oral hygiene. PURPOSE The aim of this study was to compare two microabrasion techniques on improving the white spot lesions as well as subsequent enamel discoloration. MATERIALS AND METHOD Sixty extracted premolar teeth without caries and hypoplasia were sel...

to assess the effect of time and temperature (in the pumice mixing phase of olive oil extraction) on the quantity and quality features of the extracted oil, a series of experiments comprised of three levels of mixing time (10, 20, and 30 min), and three levels of mixing temperature (30, 45, and 60°c) were carried out. the recorded data were analyzed in the framework of a randomized complete blo...

damavand is a large dormant stratovolcano in the alborz mountains of northern iran located in one of the most populous provinces, which could be adversely affected by tephra fall from damavand. the youngest known eruption is a lava flow on the western flanks with an age of 7.3 ka. the volcanic products are predominantly porphyritic trachyandesite. three major young pumice deposits, named here a...