Dynamic forces, installation

Centrifugal pumps, as do most other mechanical equipment, generate dynamic forces that must be absorbed by their foundation. The foundation should have a mass that is at least five times that of the installed pump and driver. In addition, the pump assembly must be properly affixed... 

Two conditions were considered in the stress analysis of the safe Y valve installations, namely, the dynamic effects of the safe valve opening and the steady-state flow condition reached after the valve has opened and is exhausting into the stack. During the valve opening time, dynamic forces due to the hydrau3 c transients in the valve are compensated by the reaction forces f the header supports via the header. When the valve has opened, ind the steam is exhausting into the stack, the discharge thrust is compensated by the reaction forces of the stack support structure. 

The consideration of general missile effects on the barrier should include the possible deformation of the structure by local missile effects. If there is no major local deformation of the structure by penetration, then methods of energy balance and momentum balance can be used to predict the deflections or stresses in principal members for the purpose of determining whether the barrier can contain the missile and continue to perform its design function. If, however, local missile effects are severe, as they often are, an appUed force-response time history should be developed and the structural response should be analysed as for an impulse load. The dynamic loads induced by missile impacts should be considered with due attention to the frequency response of the target structure. This is particularly important when the response of the barrier may interfere with the operability of equipment either mounted directly on the barrier or installed in the vicinity of the barrier. 

For all soft matter systems the friction forces dominate any inertial forces as long as the system is viewed with focus on mesoscopic distances. Therefore, the dynamical fluctuation are of the relaxation type. Existing NSE spectrometers cover the range from fractions of a nanosecond to about 10 ns. Routinely, 1 ns-20 ns are available at most installation. After a long period, when only one NSE instrument was existing worldwide in the recent years, besides the ancestor INll, another instrument INI 5 [2] has been built at the ILL. The MESS instrument in Saclay [3] has been operational for several years. In Japan,... 

Unlike two-dimensional or flat representations in a written text or illustration, mine space is dynamic, uncertain, and multi-dimensional. Miners must orient themselves and their equipment in relationship to other miners working in the same section. As miners advance the face, they must move machines and equipment forward. As they cut coal, they change the dimensions of their environment. As they remove coal from the mine haulageways, rock strata shift in response to the changing forces, producing roof falls and eruptions. To prevent roof falls, miners must install temporary supports and, later, permanent roof supports. 

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