the aim of this paper is eliminating cr(vi) by natural hap. hap is a inexpensive material which is used from bovine critical bone ash in order to remove heavy metal ions like cr(vi). some experiments in different ph are performed (ph=2,3,7). maximum adsorption was appeared at ph=2, dosage=0.3 gr, c0=10 mg/l. cr(vi) removal depends on ph value and initial amount of cr(vi) result of experiments w...

This paper focuses on some fracture toughness tests performed on the pre-cracked Brazilian specimens of rock-like materials. Also the effect of rock fracture filling on the fracture toughness was considered experimentally.  Fracture toughness is a key parameter for studying the crack propagation and fragmentation processes in rock structures. Fracture mechanics is an applicable tool to improve ...