Imaging Process Control for Mining and Cominution of Construction Materials
Extraterrestrial mining activities will at first be concerned with the production of construction materials. Rock and earth materials can provide the strongest and most cost effective solutions. Scarce resources (energy, human intervention) in extraterrestrial mining operations, will limit many types of activities. At the same time, construction materials need to be processed, including blasting, crushing, screening, and milling, to exact specifications. Automation is the key to minimizing resource utilization, and optical sizing is crucial for these tasks, enabling automated process control without requiring excessive human quality control strategies.
History and expansion of the Panama Canal
Abstract PREFACE: 'The creation of the Panama Canal was far more than a vast, unprecedented feat of engineering. It was a profoundly important historic event and a sweeping human drama not unlike that of war. Apart from wars, it represented the largest, most costly single effort ever before mounted anywhere on earth. It held the world's attention over a span of forty years. It affected the lives of tens of thousands of people at every level of society and of virtually every race and nationality. Great reputations were made and destroyed. For numbers of men and women it was the adventure of a lifetime. Because of it one nation, France, was rocked to its foundations. Another, Colombia, lost its most prized possession, the Isthmus of Panama. Nicaragua, on the verge of becoming a world crossroads, was left to wait for some future chance. The Republic of Panama was born. The United States was embarked on a role of global involvement'. The widening of the Panama Canal to approximately 40 m (130 ft) for its enti...
Three-dimensional elasticity problems for the prismatic bar
A general solution is given to the three-dimensional linear elastic problem of a prismatic bar subjected to arbitrary tractions on its lateral surfaces, subject only to the restriction that they can be expanded as finite power series in the axial coordinate z. The solution is obtained by repeated differentiation of the tractions with respect to z, establishing a set of sub-problems . A recursive procedure is then developed for generating the solution to from that for . This procedure involves three steps: integration of the stress and displacement fields with respect to z, using an appropriate Papkovich–Neuber (P–N) representation; solution of two-dimensional in-plane and antiplane corrective problems for the tractions in that are independent of z; and expression of these corrective solutions in P–N form. The method is illustrated by an example.