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Based on the experimentally discovered regularity – emission of micro-sized particles during monoaxial deformation of non-homogeneous structures, such as rocks and concretes, a sensor technology to identify their pre-destruction processes is proposed. At nearing the stressed state until the disintegration of the massifs, exponential increase of particles generation appears. The innovation is applicable to risky rock formations where vertical measurement boreholes are made, by which kernels are obtained. Using the specimens formed by the kernels, through monoaxial load by press in laboratory conditions and corresponding particle emissions, the reference pressure values for different stages of the pre-destructive state development are determined. The reference data from the pressure are compared with the results for the deformation loads in the rock structure, corresponding to the generated particles in a borehole model. The values of the stress determine the occurrence of critical states in the structure. This information is an integrated indicator for the timely identification of pre-destructive processes in rocks. The described system increases the accuracy of determining the appearance of failure conditions. One of the strategic applications of the new technology is in seismically active regions.

Regularity has been observed in the generation of microparticles during uniaxial deformation of rocks and building concretes with the following formula: a previously unknown phenomenon in solid non-regular structures has been experimentally established and investigated, which is expressed in emission of microparticles under the action of strong uniaxial pressures. The size and amount of the fine-dispersed microfractions depend on the substance’s physicalmechanical properties and pressure values. The paper presents the first results of the observed phenomenon in rock structures – granite and limestone originating from some regions of Bulgaria. The effect motivates the option for using the emission process as a new sensor method for assessment of the stress condition of solid-state systems.

A novel method and a device measuring the mobility of majority carriers in semiconductors using the Hall current is proposed and experimentally tested. The geometry of the mobility-determining structures is similar to the topology of the so-called Corbino disk. The semiconductor wafer, in our case, n-silicon, has circular form and two concentric ohmic contacts: one of them in the central zone of the disk, and the other around the circumference. In contrast to this well-known Corbino configuration, the peripheral electrode is interrupted, whereas the size of the so-formed arc is many times smaller than the remaining section of the external perimeter. The two ohmic contacts are brought together to a current source, and the external magnetic field is applied perpendicularly to the disk plane. The ends of the interrupted electrode are connected to an electronic galvanometer measuring the Hall current involved in the Corbino structure. The experiments were carried out at room temperature and in liquid nitrogen. The results obtained with the new device are comparable to the previously known mobility values.