Alternative statements of optimal load-bearing structure design problems

We analyze the well-known statements of optimal design problems for load-bearing maximum rigidity structures in which a principle of the minimum of total potential energy of structure deformation is used. A version of the generalized statement of optimization problems for processes described by linear equations with a symmetric operator is proposed. On the basis of the version outlined, we present a mathematical algorithm for obtaining beam structures of maximum rigidity, in which the finite element method is used to solve an analytical problem. We give the numerical results of solving two problems of optimal design of maximum rigidity structures that are simulated by cantilever and statically indeterminate beams.     

Mineralization of wastes of human vital activity and plants to be used in a Life Support System

Available methods for mineralizing wastes of human activity and inedible biomass of plants used in this country and abroad are divided into two types: dry mineralization at high temperatures up to 1270 K with subsequent partial dissolution of the ash and the other--wet oxidation by acids. In this case mineralization is performed at a temperature of 470-460 K and a pressure of 220-270 atmospheres in pure oxygen with the output of mineral solution and dissoluble sediments in the form of scale. The drawback of the first method is the formation of dioxins, CO, SO2, NO2 and other toxic compounds. The latter method is too sophisticated and is presently confined to bench testing. The here proposed method to mineralize the wastes is in mid-position between the thermal and physical chemical methods. At a temperature of 80-90 degrees C the mixture was exposed to a controlled electromagnetic field at normal atmospheric pressure. The method merits simplicity, reliability, produces no dissoluble sediment or emissions noxious for human and plants. The basic difference from the above said methods is to employ as an oxidizer atomic oxygen, its active forms including OH-radicals with hydrogen peroxide as the source. Hydrogen peroxide can be produced with electric power from water inside the Life Support System (LSS).