background: catalytic ozonation has recently been applied as a new method of contaminant removal from water and wastewater. in this study, copper coated pumice and zeolite were used to catalyze the ozonation of phenol as a target pollutant from aqueous solutions. methods: the pumice and zeolite stone were modified by cuso 4 (1n). modified pumice and zeolite were characterized by adsorption/deso...

The reutilization of wastewater is a key issue with regard to long-term space missions and planetary habitation. This study reports the design, test runs and microbiological analyses of a fixed bed biofiltration system which applies pumice grain (16-25 mm grain size, 90 m(2)/m(3) active surface) as matrix and calcium carbonate as buffer. For activation, the pumice was inoculated with garden soi...

PURPOSE The purpose of this study was to evaluate the effect of material characteristics, preparation techniques, and fissure morphology on the microleakage and penetrability of pit and fissure sealants. METHODS Sealants used in the study included: (1) Aegis; (2) Conseal f; (3) Admira Seal; (4) Triage; and (5) Delton Opaque. A total of 100 extracted permanent molars were randomly assigned to ...

PURPOSE The purpose of this study was to evaluate the effect of provisional cement removal by different dentin cleaning protocols (dental explorer, pumice, cleaning bur, Er:YAG laser) on the shear bond strength between ceramic and dentin. MATERIALS AND METHODS In total, 36 caries-free unrestored human third molars were selected as tooth specimens. Provisional restorations were fabricated and ...

The rubbing application of a hydrochloric acid-pumice mixture has been advocated for the removal of fluorotic-like areas of permanent teeth. However, there have been no previous reports as to the amount of enamel removed during this process. The objective of this project was to measure the amount of enamel lost during successive rubbing applications of an 18% HCl-pumice mixture. Nine extracted ...

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. MATERIALS AND METHODS Ninety freshly extracted healthy maxillary premolar teeth were randomly selected for this investigation. Teeth were then di...

Cooling rates inferred from water speciation in rhyolitic glass inclusions in quartz phenocrysts from the Bishop Tuff, California, vary over more than 5 orders of magnitude from about 10 to <10–4 C s–1. Many of the cooling rates are within the previously published, experimentally calibrated range of this technique but the slowest rates (<10–4 C s–1) are extrapolated. Such extrapolation suggests...

This paper presents and discusses the Neutron Activation Analysis (NAA) results newly obtained from pumice pieces found decades ago at the Egyptian sites of Maiyana, Sedment, Kahun, and Amarna – now in the collections of the Ashmolean Museum, Oxford, and the Petrie Museum of Egyptian Archaeology, London – which could be successfully related to several volcanic eruptions in the Mediterranean. Th...