in this paper, after collecting the rock samples from eight mines and one high way slope, the tests for determination of dry density, uniaxial compressive strength, tensile strength (brazilian test), elastic modulus, schmidt hammer rebound number have been done on samples. in addition, in order to calculating the mean size of rock grains, quartz content, hardness and abrasivity, a thin sections...

In this paper, after collecting the rock samples from eight mines and one high way slope, the tests for determination of dry density, Uniaxial Compressive Strength, tensile Strength (Brazilian Test), elastic modulus, Schmidt hammer rebound number have been done on samples. In addition, in order to calculating the mean size of rock grains, quartz content, hardness and abrasivity, a thin sections...

Among the power drills ( Electrical/ Pneumatic/Battery ) used in Orthopedic surgery, battery drill has got several advantages. Surgeons in low resource settings could not routinely use Orthopedic battery drills (OBD) due to the prohibitive cost of good drills or poor quality of other drills. “Hardware” or Engineering battery drill (HBD) is a viable alternative to OBD. HBD is easy to procure, ru...

In this paper, the piston rebound common to both the Schmidt Impact Hammer and downhole hammer drills has been analyzed and calculated by means of stress wave theory and the energy conservation law. A quantitative relationship between the amount of rebound of the piston and the impact resistance index, or hardness of the rock, has been established. Those analytical results will not only be of b...

among the power drills ( electrical/ pneumatic/battery ) used in orthopedic surgery, battery drill has got several advantages. surgeons in low resource settings could not routinely use orthopedic battery drills (obd) due to the prohibitive cost of good drills or poor quality of other drills. “hardware” or engineering battery drill (hbd) is a viable alternative to obd. hbd is easy to procure, ru...

OBJECTIVES To compare the noise and vibration levels associated with three hand-held rock drills (pneumatic, hydraulic and electric) currently used in South African mines, and a prototype acoustically shielded self-propelled rock drill. METHODS Equivalent A-weighted sound pressure levels were recorded on a geometrical grid, using Rion NL-11 and NL-14 sound level meters. Vibration measurements...

Among the power drills (Electrical/Pneumatic/Battery) used in Orthopedic surgery, battery drill has got several advantages. Surgeons in low resource settings could not routinely use Orthopedic battery drills (OBD) due to the prohibitive cost of good drills or poor quality of other drills. "Hardware" or Engineering battery drill (HBD) is a viable alternative to OBD. HBD is easy to procure, rugge...

Determination and analysis of vibration behavior of structures for at least first few natural frequencies and mode shapes needs several sensors to be connected at different non node points and exciting the structure at one point. Other method for determination of first few mode shapes is to excite several points of the structure at once and sensing the response from one point.  Both methods nee...

Drilling consists of 2 processes: breaking the formation with a bit and removing the drilled cuttings. In rotary drilling, rotational speed and weight on bit are used to control drilling, and the optimization of these parameters can markedly improve drilling performance. Although fluids are used for cuttings removal in terrestrial drilling, most planetary drilling systems conduct dry drilling w...