One of the most crucial factors involved in the optimum design and cost estimation of rock sawing process is the rock abrasivity that could result in a significant cost increase. Various methods including direct and indirect tests have been introduced in order to measure rock abrasivity. The Schimazek’s F-abrasiveness factor ( ) is one of the most common indices to assess rock abrasivity.  is t...

Dentifrice abrasiveness and brushing time may increase color change (∆E) and surface roughness (∆Ra) of resin composites. This study aimed to evaluate the effect of mechanical brushing time of dentifrices with different abrasiveness on ∆E and ∆Ra of nanofilled (Z350, 3M ESPE) and nanohybrid (Tetric N-Ceram, Ivoclar Vivadent) resin composites. Sixteen specimens (12 mm diameter x 2 mm thick) were...

Boron carbide (B4C) has been studied under dry sliding conditions for use as a potential finite-life run-in coating. Such a coating has been found to polish its mating surface during dry sliding wear, thereby providing fatigue resistance to the coated part. Employing such run-in coatings requires a complete understanding of the changes that occur in the coating abrasiveness during the polishing...

Understanding interactions between grasses and their herbivores is central to the conservation of species-rich grasslands and the protection of our most important crops against pests. Grasses employ a range of defenses against their natural enemies; silicon-based defenses have been shown to be one of the most effective. Silicon (Si) is laid down on the leaf surface as spines and other sharp bod...

Rock abrasiveness is ability of rock to wear down the working tool during the mutual interaction between the working indentor and the rock in the mechanical rock cutting process. The cutting indentor is worn down during the interaction, which changes its geometric dimensions causing the enlargement of a contact area between the tool and the rock surface. The changes in these dimensions conseque...

Lactose, one of the most commonly used fillers in solid dosage formulations, is well known for producing tablets with high mechanical strength. However, its usage has been eroded by some relatively recent concerns, such as Bovine Spongiform Encephalopathy BSE, Variant Creutzfeldt-Jacob Disease (vCJD), and lactose intolerance. These concerns have led some formulators to evaluate other excipients...

Dietary characteristics and environmental variables are important selective factors directing ecological diversification in rodents. On Madagascar, the introductions and spread of the commensal black rat (Rattus rattus) can be seen as example cases to study dietary niche occupation and dietary adaptation in an insular environment. We investigate how tooth wear as a measure of dietary adaptation...

Finding a wear law that is valid over a wide range of conditions and materials would have enormous practical value. The authors have previously iscovered a simple relationship describing the evolution of the abrasive wear rate of steel sliding against boron carbide-coated coupons, and have eveloped a model accounting for its kinetics. The authors show here that this wear equation accurately des...

The impact of plant-based factors on the population dynamics of mammalian herbivores has been the subject of much debate in ecology, but the role of antiherbivore defences in grasses has received relatively little attention. Silica has been proposed as the primary defence in grasses and is thought to lead to increased abrasiveness of foliage so deterring feeding, as well as reducing foliage dig...