In this paper, the adsorption of Congo red dye from an aqueous solution using chitosan-coated pumice (CCP) has been studied. The abundant natural Irind mine (Republic Armenia) was successfully activated by acid activation method and modified with chitosan. adsorbent applied as a low-cost, environmentally-friendly for removal solution. samples were characterized Fourier-transform infrared spectr...

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 ...

Pumice rafts are floating mobile accumulations of low-density pumice clasts generated by silicic volcanic eruptions. Pumice in rafts can drift for years, become waterlogged and sink, or become stranded on shorelines. Here we show that the pumice raft formed by the impressive, deep submarine eruption of the Havre caldera volcano (Southwest Pacific) in July 2012 can be mapped by satellite imagery...

Pumice aggregate, which has high reserves in our country, is used the production of lightweight concrete, however, it not preferred as a structural concrete since its low mechanical properties. The properties pumice aggregates can be improved by coating their surfaces. In this way, coated to produce concrete. This study investigated potential Kayseri and Ahlat with cement paste. flow diameter, ...

AIM & OBJECTIVES The purpose of this in vitro study was to evaluate and compare the microleakage of pit and fissure sealants after using six different preparation techniques: (a) brush, (b) pumice slurry application, (c) bur, (d) air polishing, (e) air abrasion, and (f) longer etching time. MATERIAL & METHOD The study was conducted on 60 caries-free first premolars extracted for orthodontic p...

A novel concept in internal curing of High Performance Concrete is based on dispersing very small, saturated lightweight aggregates (LWA) in the concrete, containing sufficient water to counteract self-desiccation. With this approach, the amount of water in the LWA can be minimized, thus economizing on the amount of the LWA. In this study, the pore structure of different size fractions of pumic...

The purpose of this study was to describe the radiological features of pleural, parenchymal and mediastinal damage due to occupational inhalation of pumice. In total, 31 workers were evaluated for annual follow-up. Spiral computed tomography (CT) was obtained in the three patients with evident parenchymal abnormalities at chest radiograph. High-resolution computed tomography (HRCT) was performe...

PURPOSE The purpose of this in vitro study was to evaluate microleakage of pit and fissure sealants after using three different pit and fissure preparation techniques: (1) traditional pumice prophylaxis and acid etching, (2) fissure enameloplasty and acid etching and (3) air abrasion and acid etching. METHODS Sixty extracted third molars with no clinical evidence of caries were randomly divid...

Pumice is an extremely effective rafting agent that can dramatically increase the dispersal range of a variety of marine organisms and connect isolated shallow marine and coastal ecosystems. Here we report on a significant recent pumice rafting and long-distance dispersal event that occurred across the southwest Pacific following the 2006 explosive eruption of Home Reef Volcano in Tonga. We hav...