In order to automate the scooping task, it is desirable that the resistive force acting on the bucket be obtained before the scooping is performed. The objective of this study is to derive theoretically the resistive forces acting on the bucket during scooping of piled rock fragments. First, the changes in the shape of the rock pile due to the penetration of it by the bucket are modeled. Based ...

Abstract. The purpose of the Wedge Splitting Test (WST) is to generate stable mode I fracture crack along a pre-established path, and be able to measure the specific fracture energy parameter of the material GF. The test is performed on standard cylindrical notched specimens. In order to make decision on the optimal notch geometry for a specific rock test, a number of WST experiments were simul...

Standards-based score reports interpret test performance with reference to cut scores defining categories like "below basic" or "proficient" or "master." This paper first develops a conceptual framework for validity arguments supporting such interpretations, then presents three applications. Two of these are serve to introduce new standard-setting methods. The conceptual framework lays out the ...

UNLABELLED The Atraumatic Restorative Treatment (ART) approach was suggested to be a suitable method to treat enamel and dentine carious lesions in patients with disabilities. The use of a restorative glass-ionomer with optimal mechanical properties is, therefore, very important. OBJECTIVE To test the null-hypotheses that no difference in diametral tensile, compressive and flexural strengths ...

The particle size distribution of fragmented rock in mines significantly affects operational performance of loading equipment, materials handling and crushing systems. A number of methods to measure rock fragmentation exist at present, however these systems have a number of shortcomings in an underground environment. This paper outlines the first implementation of high resolution 3D laser scann...