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...

The input admittance at the bridge, measured by hammer testing, is often regarded as the most useful and convenient measurement of the vibrational behavior of a bowed string instrument. However, this method has been questioned, due especially to differences between human bowing and hammer impact. The goal of the research presented here is to investigate the reliability and accuracy of this clas...

Slips are a leading cause of falls. (Manning, Ayers et al. 1988; Bentley and Haslam 1998) In the work environment, slipping has been identified as the primary antecedent event to falls on both stairs and level surfaces. (Bentley and Haslam 1998) Among community dwelling elderly, slips contributed to 38% and 17% of falls experienced by men and women, respectively. (Berg, Alessio et al. 1997) In ...

Currently, in civil engineering, high performance concrete i.e. concretes whose minimum compression strength is equal or more than 65 MPa are increasingly used. Side effect of it is need for determination of their construction strength. In particular, recently built high performance structures suffer from sampling of drill cores. Therefore, noninvasive impact hammers – to be specific Schmitt im...

Row hammer attacks exploit electrical interactions between neighboring memory cells in high-density dynamic random-access memory (DRAM) to induce memory errors. By rapidly and repeatedly accessing DRAMs with specific patterns, an adversary with limited privilege on the target machine may trigger bit flips in memory regions that he has no permission to access directly. In this paper, we explore ...

In the construction industry, non-destructive testing (NDT) methods are gaining more popularity for their ability to examine the in-situ component properties without damaging the structure. One of the most common NDTs for measuring the concrete compressive strength on site is the Rebound Hammer Test. Using the rebound value obtained from the test hammer, the concrete compressive strength can be...

Introduction: This study aims to determine the amount of hand-arm vibration transmitted from heavy electric destruction tools and the effect of using chisel with different lengths and shapes when demolishing concrete surfaces. Material and Methods: To evaluate the magnitude of hand-arm vibration on the left and right handles of two powerful electric demolition hammers commonly applied in Irani...