نتایج جستجو برای: pumice powder
تعداد نتایج: 47653 فیلتر نتایج به سال:
Arsenic contamination of water has been recognized as a serious environmental issue and there are reports on its epidemiological problems to human health. The objective of this study was to evaluate the performances of iron-coated pumice and manganese-coated pumice as the adsorbents for removing arsenate from aqueous solutions. The effect of various parameters such as adsorbent dose, contact ti...
A good enamel cleaning before acid etching is necessary to prepare esthetic and functional direct and indirect restorations and fissure sealants [1,2]. Plaque and discolorations are removed by dental prophylaxis technique with pumice powder or paste and rotating brush or small rubber cup [3], there are other techniques like air-flow and bicarbonate jet polisher, which are as operative as the ot...
[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...
background and aims. this study was aimed at evaluating the effect of different prophylaxis methods on microleakage of microfilled composite restorations. materials and methods. in this in vitro study, class v cavities were prepared on buccal surfaces of 84 bovine teeth. the teeth were restored with tetric n-bond adhesive and heliomolar composite resin. subsequent to a thermocycling procedure a...
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