OBJECTIVE This in situ study aimed to analyse the impact of different tetrafluorides (TiF(4), ZrF(4) and HfF(4)) and AmF on erosion and erosion plus abrasion of enamel and dentin. DESIGN Ten volunteers took part in this crossover and double-blind study performed in 8 phases of each 3 days. In each phase, 2 bovine enamel and 2 dentin specimens were fixed in intraoral appliances. One enamel and...

A cross-sectional study was performed on 225 textile workers from a wool production company in Montenegro to test the hypothesis of a relationship between exposure to intense industrial noise and tooth abrasion. The group exposed to intense noise (104 dB (A) Leq) consisted of 111 weavers (82 males and 29 females), while the control group (81 dB (A) Leq) consisted of 114 blue-collar workers (32 ...

The taphonomy of assemblages of disarticulated remains of marine vertebrates is not well studied. Examination of a Middle Pennsylvanian chondrichthyan assemblage from Kohl’s Ranch, Naco Formation, central Arizona, contributes to knowledge of such assemblages and reveals a complex taphonomic history. This vertebrate assemblage is restricted to two thin horizons associated with a concentration of...

Climbing on vertical concrete structures like bridge pylons or dams is still a great challenge for autonomous robots. This paper presents the forceand traction control system of the climbing robot Cromsci which uses a negative pressure system for adhesion and driven wheels for propulsion. Especially in vertical environments the propulsion system must be able to produce enough force for carrying...

The results of theoretical and experimental investigations carried out to study the effect load relative sliding speed on abrasive wear behavior in drilling bit teeth surfaces an insert tungsten carbide have been presented. Experimentally, apparatus for tests conducted modified ASTM-G65 was fabricated facilitate loading measurement rate sand/ steel wheel abrasion test, which involves two cases ...

PURPOSE The purpose of this study was to investigate the impact of different surface treatment methods and thermal ageing on the bond strength of autopolymerizing acrylic resin to Co-Cr. MATERIALS AND METHODS Co-Cr alloy specimens were divided into five groups according to the surface conditioning methods. C: No treatment; SP: flamed with the Silano-Pen device; K: airborne particle abrasion w...

Abstract Fusion-bonded and low-diluted overlay welded coatings are frequently very thick (>1mm). High-speed laser cladding is a novel process capable of producing thin fusion-bonded with high coverage rates low heat input. In this study, for the first time, high-speed was used to fabricate relatively Ni-based reinforced chromium carbides onto low-alloy structural quenched tempered steels. Ob...

statement of problem: in some clinical situations, repair of composite restorations is treatment of choice. improving the bond strength between one new and old composite usually requires increased surface roughness to promote mechanical interlocking since chemical bonding might not be adequate. similarly, the treatment of a laboratory fabricated resin composite restoration involves the same pro...

This paper presents a new approach for modelling the wear in wheel-rail contacts wide range of test and contact conditions (material pairing, load, creep, lubrication etc.) mild severe regimes with one set model coefficients. The is based on detailed analysis 56 Twin-Disc experiments combination existing knowledge from literature. considers thickness damaged layer caused by plastic shear deform...

During sowing of pesticide-treated seeds, pesticide-laden dust and abraded seed particles may be emitted to the environment, possibly leading to environmental contamination and posing health risks. In many countries there is currently no legislation concerning the acceptable amount of dust of treated seeds. This study aimed to gain insight in the abrasion potential of available pesticide-treate...