It is well known that pebble diameter systematically decreases downstream in rivers. The contribution of abrasion is uncertain, in part because (1) diameter is insufficient to characterize pebble mass loss due to abrasion and (2) abrasion rates measured in laboratory experiments cannot be easily extrapolated to the field. A recent geometric theory describes abrasion as a curvature-dependent pro...

There are different test methods to determine the abrasion resistance of concrete subjected to number of various types of abrasion. There are number of different tests used in various countries and it is clear that there is no single test that adequately measures the abrasion resistance of concrete under all conditions. This paper covers the summary and classification of the various abrasion te...

introduction: video-assisted thoracic surgery (vats) is now commonly used for primary spontaneous pneumothorax. in the present study we compared the outcomes of this technique with those obtained by conventional thoracotomy.material and methods: in this cross-sectional stud, forty patients were enrolled into two groups: vats (n=20) and thoracotomy (n=20). in both groups the blebs were resected ...

This study investigated the efficacies of adhesive resin cements (Clearfil SA Luting, Maxcem, G-CEM, RelyX Unicem Clicker, Vitremer Paste) for bonding to Ag-Pd-Cu-Au alloy not surface-pretreated with metal primer. For control, Panavia F 2.0 -developed for use with a proprietary metal primer, Alloy Primer- was tested with and without metal primer application. Pairs of alloy disks (10.0 and 8.0 m...

Purpose: The purpose of this study was to investigate the effects of two air-abrasive prophylaxis systems and the effect of inlet air pressure on the surface of Brhnemark titanium abutment cylinders. Materials and Methods: Single abutment cylinders were treated with either the Prophy-Jet system (sodium bicarbonate abrasive) (Dentsply International, York, PA) or the Microprophy system (aluminum ...

An important factor in material quality is the time duration that materials are used (known as substance lifetime). Lifetime is a function of several factors, and among them wearing and abrasion resistances are more important than the other aspects. In addition, to the physical and mechanical properties, abrasion has a significant effect on the textiles appearance. This phenomenon considerably ...

In the actual working conditions, ship lock concrete is affected by friction of ship’s hull and erosion wear traveling wave during flood period damaged CO2 in air waterfall period. To study performance degradation law under this condition, underwater method was used to approximate physical rising water period, accelerated carbonization simulate falling The duration abrasion are determined accor...

The potential formation and the size of microgaps at material/dentin interface after various surface modifications a resin-matrix computer-aided design/computer-aided manufacturing (CAD/CAM) ceramic following artificial aging was investigated. Fifty human third molars were used, CAD/CAM ceramic, Lava Ultimate, resin cement material, Rely X tested. blocks sectioned, each slab luted on tooth usin...

In this study, the synergistic effects of abrasion and corrosion on AISI 316L stainless steel have been investigated using a micro-abrasion test rig. A series of results from abrasioncorrosion tests conducted using the micro-abrasion rig are presented. AISI 316L stainless steel has been studied under both pure abrasion and abrasion-corrosion conditions simulated by either distilled water or 3.5...

BACKGROUND AND OBJECTIVES The effectiveness of air bags as a safety device in decreasing fatalities and reducing morbidity in frontal impact motor vehicle accidents has been well established. However, case reports have surfaced documenting ocular injuries related to air bag inflation. The purpose of this study was to identify and analyze ocular injuries sustained during air bag inflation. PAT...