background: some studies have shown that casein phosphopeptide-amorphous calcium phosphate (cpp-acp) and acidulated phosphate fluoride (apf) gel can protect teeth against erosion. the aim of this study was to assess whether cpp-acp and fluoride could reduce enamel wear rates under erosive conditions simulating abrasion and acidic diet regimen. materials and methods: enamel specimens consisted o...

statement of problem: as a physical property, wear resistance of the materials used in the fabrication of orthodontic retainers play a significant role in the stability and long term use of the appliances. objectives: to evaluate the wear resistance of two commonly used materials for orthodontic retainers: acropars op, i.e. a polymethyl methacrylate based material, and 3a-gs060, i.e. a polyethy...

In this study, the integrated Taguchi-simulated annealing (SA) approach is applied to examine the wear behaviour of silicon nitride (Si3N4)hexagonal boron nitride (hBN). Wear tests for Si3N4-hBN composite versus steel (ASTM 316L) disc were carried out for a dry sliding conditions in a so-called pin-on-disc arrangement. The tests were realized at % volume of hBN 0, 4, 8, 12, 16 in Si3N4 under th...

OBJECTIVE The present study aimed to examine the impact of non-wear activities registered in diaries when using accelerometers to assess physical activity (PA) in young adolescents. DESIGN Data arise from a large-scale cross-sectional study on PA. PA was objectively assessed using Actigraph™ accelerometers (Actigraph MTI, Manufacturing Technology Inc., Pensacola, FL, USA) during seven consecu...

aa8090 is an extra light and deformable group of lithium containing aluminum alloys which have recently replaced some aerospace aluminum alloys, such as 2000 and 7000 series, due to their higher elastic modulus and lower specific weight. in this study, aa8090 matrix composites containing 3, 6 and 9 vol.% sic were cast using a modified stir casting method. the casting billets were deformed thoug...

Journal bearings used in IC engines are prone to premature failures and are likely to fail earlier than the rated life due to highly impulsive and unstable operating conditions and frequent starts/stops. Vibration signature extraction and wear debris analysis techniques are prevalent in industry for condition monitoring of rotary machinery. However, both techniques involve a great deal of techn...

This paper investigates the mechanical erosion of the metal tubes in bagasse-fired boilers with the aid of the acoustic emission technique. By studying the material removal under various collision conditions, the paper analyzes the dependence of the erosion wear upon the impact angle, velocity, size and concentration of the particles. It was found that the material removal mechanisms were mainl...

Wear is a complicated phenomenon caused by the relative movement of two contacting surfaces compressed together by a normal force. Prediction of the wear, in most cases, requires various experiments and microstructural characterization of the contacting surfaces. Mathematical models based on physical concepts could provide considerable help in understanding the physical behavior and hence the p...

Wear is a complicated phenomenon caused by the relative movement of two contacting surfaces compressed together by a normal force. Prediction of the wear, in most cases, requires various experiments and microstructural characterization of the contacting surfaces. Mathematical models based on physical concepts could provide considerable help in understanding the physical behavior and hence the p...