[1] Using a high-speed video camera, we studied oblique collisions of lapilli-size pumice cylinders (with no rotation before impact) on flat pumice targets. Our results show that the rebound angle, the ratios of the components of velocities and the energy loss vary with the impact angle. In particular, in collisions with an average yaw angle approximately equal to zero, we observed relatively l...

We report the results of a research carried out in Turkey in 2004 to determine the effectiveness of different levels of pumice amendments to soil using strawberry plants. Two grades (2-4 mm and 4-8 mm) of pumice were added to soil and three amendment levels (15%, 30% and 45% by volume) were applied. Finally 6 different growing media types were formulated. The amount of moisture retained at diff...

The Sangiran dome is the primary stratigraphic window for the Plio-Pleistocene deposits of the Solo basin of Central Jawa. The dome has yielded nearly 80 Homo erectus fossils, around 50 of which have known findspots. With a hornblende (40)Ar/(39)Ar plateau age of 1.66 +/- 0.04 mega-annum (Ma) reportedly associated with two fossils [Swisher, C.C., III, Curtis, G. H., Jacob, T., Getty, A. G., Sup...

Volcanic eruptions are a widespread force of geological and ecological disturbance and present recurrent opportunities for the study of biological responses to novel habitat formation. However, scientific study of such events is difficult given their short duration and often distant location. Here we report results from opportunistic sampling of unique volcano-generated habitats formed during t...

The aim of this study was to evaluate the use of fluoride varnish as a prophylaxis method with self etching primer (SEP) and its comparison with pumice before orthodontic bonding. Thirty seven orthodontic patients participated in a prospective clinical trial. A split mouth technique was used in each patient, one quadrant was assigned to fluoride varnish and the contralateral quadrant to pumice ...

OBJECTIVES Plaque and stains are removed by prophylaxis methods from tooth surfaces. Since prophylaxis methods can have a detrimental effect on the surface finish of restorations, the aim of this in vitro study was to investigate the effect of three prophylaxis methods, including pumice with rubber cup, pumice with brush, and air-powder polishing device (APD) on the surface roughness of giomer....

conclusions according to this study, pumice powder and slurry used in dental laboratories of hamadan are contaminated. therefore, the laboratory staff should be aware of the hazards posed by the presence of pathogens in dental laboratories. materials and methods forty specimens, including 20 pumice powders and 20 pumice slurries were collected from 10 randomly selected dental laboratories and i...

The method of preparing the distilled nutrient medium has been improved, thus rendering the cultivation of the bacillus leprae in this medium much more potent for the preparation of leprolin. Small pieces of pumice stone are washed and dried in the sun, and then made to absorb beef extract; they are then placed in bottles having a wide central tube leading to the bottom, aiuKin outlet tube at t...

Colored effluents are one of the important environment pollution sources since they contain unused dye compounds which are toxic and less-biodegradable. In this work removal of Acid Red 14 and Acid Red 18 azo dyes was investigated by acidic treated pumice stone as an efficient adsorbent at various experimental conditions. Removal of dye increased with increase in contact time and initial dye co...