Electronic control hydraulic impactor based on pressure feedback
The impact energy of the traditional hydraulic impactor can be regulated manually between the second and the third grade, and its impact frequency can not be adjusted independently. Also, they have to stop working for adjustment. In order to alter this situation, a new hydraulic impactor DBS500, which controlled by micro-electronic system, has been designed and its functions are showed as following: The impact energy can reach 500 joules and its impact frequency also realizes regulation from 0 to 8Hz steplessly. It can estimate the work object's nature by piston's rebound behavior. It can self-regulate the impact energy and frequency according to the object's nature, so that can improve the working efficiency and adapt the power of the loader.
Dynamic Determination of Pile Capacity
A method is presented for determining the axial static pile capacity from dynamic measurements of force and acceleration made under the impact of a large hammer. The basic equation for calculation of the forces resisting pile penetration is derived. The limitations of the basic resistance equation are discussed and illustrative examples of field measurements are given. With the availability of this derivation, it is possible to prove that the Case Pile Wave Analysis Program (CAPWAP) resistance force distribution is unique. Using the assumption that the resistance to penetration can be divided into static and dynamic parts, an expression is developed for calculating the dynamic, resistance to penetration. The resulting method requires the selection of a damping constant which is shown empirically, to relate to soil size distribution. A correlation of Case Method capacity and the capacity observed in static logd tests is given for 69 statically tested piles that were also tested dynamically.
Physical Chemistry for the Life Sciences
PART 1 - BIOCHEMICAL THERMODYNAMICS PART 2- THE KINETICS OF LIFE PROCESSES PART 3 - BIOMOLECULAR STRUCTURE PART 4 - BIOMOLECULAR SPECTROSCOPY