The presence of porosity in a material was first shown by Robert Hooke (1635–1703) who, in his investigations of the natural world using the newly available microscope, observed that the structure of cork was based on regular hollow units which he termed “cells”, because they reminded him of the cells of a monastery. Indeed, the fact that most natural structures are porous is a clear indication...

The presence of capillary pores and air voids influences concrete permeability to a large extent. Concrete density is inversely proportional to its porosity. The ingress of aggressive agents into the pore structure is responsible for various durability problems in concrete structures. Therefore, a durable concrete should have low permeability. Permeability of concrete increases with the increas...

in exploration seismology, estimation of elastic parameters of rocks using seismic amplitudes is considered as inverse problems. nowadays, model-based and more generally optimization-based algorithms are of the most common methods of seismic inversion. these algorithms which are known as deterministic methods, are suffering from two main problems; first, vertical resolution of outputs is very l...