A Novel Sensor Effect Applicable in Seismically Active Regions †
Institute of Robotics at Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
*
Author to whom correspondence should be addressed.
†
Presented at the XXXV EUROSENSORS Conference, Lecce, Italy, 10–13 September 2023.
Proceedings 2024, 97(1), 102; https://doi.org/10.3390/proceedings2024097102
Published: 27 March 2024
Abstract
:This paper reports a novel sensor effect in solid non-regular materials with the following formula: a previously unknown phenomenon in solid disordered structures, such as rocks and building concrete, has been experimentally established, which is expressed in the emission of micro-sized particles under the action of uniaxial pressures. The obtained results are an integrated technology indicator for pre-emergency and emergency conditions in mountain massifs and are applicable in seismically active regions.
1. Introduction
In recent years, the study of micro- and nano-sized particles, including the fabrication of nanomaterials, has been a priority in the scientific and technological fields. An important direction is the determination of the physico-mechanical condition of rocks as an indicator for pre-destruction and disintegration processes in the Earth’s crust. The emission of rock microparticles by explosion, as well as the extraction of ores negatively affect the ecosystem. A great number of sensor devices investigating the deformation condition of rock massifs and concrete have been developed. The improvement of the available instruments is very important for the extraction industry, urbanization, bridges, dam walls, and more. There is another strategically significant problem related to various natural catastrophes—the displacement of tectonic plates and seismic faults. The new information about this process expands the database of potential causes through which the earthquake models are improved. Recently, a new phenomenon has been experimentally observed—the emission of microparticles in rock samples under uniaxial pressures. The paper presents the results of this effect and its relation to seismically active regions.
2. Experimental Setup
The methodology of the phenomenon’s investigation involves the following sequence: From a rock piece, a cylindrical, parallelepiped or cube test sample is cut out. The test body is placed into an air-proof, closed box with a regular geometric form. This measurement volume is connected to an air filter and a counter for mineral particles. The rock sample is placed between the plates of a press generating monoaxial pressure. The rock probe is placed inside a closed box—a hollow cylinder, a cube, or a parallelepiped made of hard material without an upper and lower bottom. The two bottom zones of the box, whose size is greater than the size of the rock sample, are enveloped by flexible muffs. To the hollow body, two air conductors are attached, connected to the laser particle counter and the air filter, as shown in Figure 1. The sensor information about the amount and size of the mineral fractions released by the deformed structure was indicated on the counter display. All experiments have been carried out after this algorithm.
3. Results and Conclusions
The experiments were carried out with parallelepiped granite, marble, and limestone specimens. For example, the microparticles from granite shown in Figure 2 and Figure 3 that were detected by the laser counter are in the ranges 0.3–0.5 µm and >5.0 µm, respectively.
When the pressure F neared F ≈ 48 MPa for granite, the number of emitted particles in the range increased faster. When the deformation reached values of about F0 ≈ 51 MPa for granite, an abrupt increase in microparticle emission started, corresponding to an occurring disintegration rock process. At reaching a pressure close to the critical value F0, exponential behaviour of the particles is observed. It has been experimentally proven that the amounts of emitted microfractions, regardless of their sizes, are reproducible for a specific rock.
On the basis of the new phenomenon, the design of sensor systems is in progress, representing technology as an indicator for the purposes of seismology. In Figure 4, a schematic configuration for permanent control of the deformation state by particle emission in the case of tectonic plate folding is shown. The first obtained results are very promising as an integrated parameter for the occurrence of upcoming dynamic processes in mountain massifs and fault zones of seismically active regions.
Author Contributions
Conceptualization, S.L. and C.R.; methodology, A.I. and M.R.; validation, S.L., M.R. and A.I.; investigation, S.L., M.R. and C.R.; resources, C.R.; writing—original draft preparation, S.L.; writing—review and editing, A.I. and C.R.; supervision, C.R.; project administration, S.L.; funding acquisition, C.R. and A.I. All authors have read and agreed to the published version of the manuscript.
Funding
This work was supported by CoC “QUASAR” under Project № BG05M2OP001-1.002-0006.
Institutional Review Board Statement
Not applicable.
Informed Consent Statement
Not applicable.
Data Availability Statement
Data are contained within the article.
Conflicts of Interest
The authors declare no conflicts of interest.
Figure 1.
Arrangement for detection of microparticles: rock test specimen 1; box 2; air filter 3; laser counter 4; press 5; flexible muffs 6; air conductors 7 and 8. The parallelepiped samples with a height of 80 mm and equal lateral ribs measuring 50 mm are subjected to uniaxial loading.
Figure 1.
Arrangement for detection of microparticles: rock test specimen 1; box 2; air filter 3; laser counter 4; press 5; flexible muffs 6; air conductors 7 and 8. The parallelepiped samples with a height of 80 mm and equal lateral ribs measuring 50 mm are subjected to uniaxial loading.
Figure 2.
Intensity of particle emission on uniaxial pressure for granite samples in the range of 0.3–0.5 μm. The experimental error is no more than 5–6%.
Figure 2.
Intensity of particle emission on uniaxial pressure for granite samples in the range of 0.3–0.5 μm. The experimental error is no more than 5–6%.
Figure 3.
Particle emission for granite, >5.0 μm.
Figure 4.
Implementation of the novel effect for seismic purposes: rock massif 1; tectonic plate 2; vertical borehole 3; hermetic stopper 4; air conductors 5 and 6; air filter 7; aerosol particle laser counter 8.
Figure 4.
Implementation of the novel effect for seismic purposes: rock massif 1; tectonic plate 2; vertical borehole 3; hermetic stopper 4; air conductors 5 and 6; air filter 7; aerosol particle laser counter 8.
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MDPI and ACS Style
Lozanova, S.; Ralchev, M.; Ivanov, A.; Roumenin, C. A Novel Sensor Effect Applicable in Seismically Active Regions. Proceedings 2024, 97, 102. https://doi.org/10.3390/proceedings2024097102
AMA Style
Lozanova S, Ralchev M, Ivanov A, Roumenin C. A Novel Sensor Effect Applicable in Seismically Active Regions. Proceedings. 2024; 97(1):102. https://doi.org/10.3390/proceedings2024097102
Chicago/Turabian StyleLozanova, Siya, Martin Ralchev, Avgust Ivanov, and Chavdar Roumenin. 2024. "A Novel Sensor Effect Applicable in Seismically Active Regions" Proceedings 97, no. 1: 102. https://doi.org/10.3390/proceedings2024097102
