Fast parallel algorithms for Graeffe's root squaring technique

AbstractThis paper presents two parallel algorithms for the solution of a polynomial equation of degree n, where n can be very large. The algorithms are based on Graeffe's root squaring technique implemented on two different systolic architectures, built around mesh of trees and multitrees, respectively. Each of these algorithms requires O(log n) time using O(n2) processors

Initiation mode of explosives vis-a-vis blast performance

Considerable progress has been achieved in recent years in the whole field of blasting science and technology. This applies to explosives formulation, initiation systems and blast simulation through advanced numerical codes. The commercial explosives in the market today are not only generally cheaper and safer than before, but also more flexible in their applications, and also geared for easy transport and delivery into the boreholes in very large volumes. The theoretical treatment of detonation process under both ideal and non-ideal conditions are noteworthy, but they are still based on somewhat hypothetical situations. The actual variables that are essential parts of normal blasting practice have not yet been taken into account in such treatments. These include the various initiation practices employed to detonate a column of explosive, from single point initiation to multi-point initiation in blastholes, and the effect of detonation characteristics of both detonators and explosives under multi-deck and multi-hole blasting conditions. The in-the-hole VOD of an industrial explosive is dependent on explosive’s charge diameter and borehole diameter. The in-the-hole VOD of explosives was measured at four experimental sites in India for different borehole diameters i.e. 150 mm to 311 mm, but the explosive composition being same particle size, density, viscosity and loaded into boreholes with the same degree of confinement. The results of the studies demonstrated that there is definite relationship in in-the-hole VOD of the explosive and the diameter of the blasthole. The study also confirmed that the explosives initiated with concentrated boosters yielded higher VOD in comparison with those explosives that were initiated with multi-point priming. The measured increase in VOD of explosives for increasing diameter of holes was up to 24%. The rate of change in in-the-hole VOD of explosives increases with increasing borehole diameter. It can be further stated that the in-the-hole VOD of the explosive reaches a farly constant value after reaching a limiting/threshold diameter of 311 mm