Thank you for your interest to our paper. In the article we tried to show that anomalies of acous... more Thank you for your interest to our paper. In the article we tried to show that anomalies of acoustic emission which we observe in Kamchatka in fair weather conditions are determined by rock deformations at the point of emission registration. In order to do that, we make simultaneous registration of rock deformations and of acoustic emission. Rock deformations may be determined both by strong remote earthquake preparation and by local effects at the point of observations. We would like to emphasize that rocks in which we register signals are sedimentary ones. According to the data of well-drilling,
The prevailing view that radioactive decay is the major thermal source for the interior of the pl... more The prevailing view that radioactive decay is the major thermal source for the interior of the planet may create limitations in geophysical modeling efforts. New theoretical insights by Gregori 2002 [1] provide for an electrical source from the coremantle-boundary (CMB) by a tide-driven (TD) geodynamo which is enhanced by various solar induction processes. Joule heating at density boundaries within the upper mantle and base of the lithosphere from CMB electrical emanations may provide some of the hotspot energy for upper mantle melts and associated magmatism driving seafloor spreading and lithospheric rupture. Estimates of the total budget of the endogenous energy of the Earth supporting the electrical hotspot hypothesis are as follows [1].
The seismic sequence in Central Italy that started in August 2016 and is still in progress in Feb... more The seismic sequence in Central Italy that started in August 2016 and is still in progress in February 2017is investigated like a pilot-study in order to focus on a multidisciplinary perspective for a realistic seismic hazard mitigation and management. A clear distinction has to be made with the “bottom-up” approach which is typical of a geologist or of a seismologist, who investigate phenomena after the occurrence of an earthquake, and upon consideration either of a subset of known phenomena – or of “all” them that are available and that preceded every given shock. Statisticians, altogether with seismologists, apply a formally rigorous and careful approach, based on complicated algorithms etc. Their rigorous approach is certainly indicative and useful for hazard management, unlike every less rigorous statistical analysis that cannot be comparably reliable. In fact, the boundary is not always clearly stated between an “implicit suitable assumption” and logical rigor. A first paper (...
American Journal of Engineering and Applied Sciences, 2021
endogenous energy. An additional gauge can be, maybe, represented by the microorganisms that are ... more endogenous energy. An additional gauge can be, maybe, represented by the microorganisms that are endemically generated at ocean floors that can perhaps justify the time evolution of pathogens maybe also some pandemics. In fact, the mutation of deep ocean biota can be, perhaps, related to the evolution of pathogens that since several decades are well-known to require the updating of all vaccines. In addition, these mutations could also be the possible cause of unprecedented pandemics, that perhaps might even impact at a possibly increasing frequency. An improved capability to detect environmental changes with a higher time-resolution is a prerequisite for understanding and managing also these disquieting and unprecedented threats.
American Journal of Engineering and Applied Sciences, 2021
A more detailed summary is given in the last part (1/4th) of the Introduction. An anomalous perio... more A more detailed summary is given in the last part (1/4th) of the Introduction. An anomalous period is in progress, characterized by a very intense release of endogenous energy from the Earth. The cause is an ongoing heartbeat of the Earth's electrocardiogram. Humankind's history spans a much shorter duration. Hence, at present the humans are going to face an unprecedented challenge, maybe even concerning survival. The duration of the climate anomaly of an Earth's heartbeat is a few Ma. The challenge is to avoid that humankind is going toward extinction. The paper attempts to give a general-and largely original and substantially advanced-perspective of Earth's phenomena. As far as possible, the approach is top-down, i.e., start from known laws and infer expected observations-unlike the more usual bottom-up viewpoint, i.e., start from observations and seek regularities. The present text is devoted to applied scientists. The overall scenario is much more focused and precise than standard treatments. The target of the paper is concerned with the possible actions that can-and must-be implemented in order to face this unprecedented challenge-rather than being concerned with a critical discussion and comparison with the present "generally agreed" geophysical models reported in the literature. In particular, the exploitation is considered of a huge reservoir of natural and clean energy. The central focus of the present paper is the exploitation of the electrostatic energy of the atmospheric electrical circuit, which is a clean and almost inexhaustible free source. It should be stressed that-as it has been proven by quantitative and precise observations-the CO2 pollution of anthropic origin provides an irrelevant-or maybe even a negligible-contribution to climate change. Climate change is, rather, caused by the natural, violent, ongoing exhalation of endogenous energy. This anomaly is going to be manifested, perhaps, by an eventual ever-increasing intensity of phenomena-including seismic and volcanic activity, energy and dynamics on the oceans and atmosphere, greater excursions with respect to the mild climate and a (presently unmonitored) change of endemic microorganism generation on the ocean floors (maybe even affecting pandemics). This study is an attempt to synthesize a wide multidisciplinary scenario, as far as possible by a limited number of pages. The purpose is only to start a much more extensive and profound discussion, that-as far as the geophysical items are concerned-is the object of more extensive studies (in preparation).
Acoustic Emissions (AE) are effective for monitoring ground deformation and temporal variation of... more Acoustic Emissions (AE) are effective for monitoring ground deformation and temporal variation of its porosity. AE are complementary to seismic information, related to the same area, though AE and earthquakes focus on observational evidence concerned with substantially different space-and timescales. AE information is pertinent (i) either for geodynamically stable areas, where it probes the diurnal thermal and/or tidal deformation, (ii) or for seismic areas where it provides some as yet unexploited precursors, (iii) or for volcanic areas, where it appears capable of recognising precursors originated by some hot fluid that penetrates by diffusion into rock pores, from those associated with eventual plutonic magma intrusions, (iv) and also for monitoring periods of time during which a volcano is «inflated» by underground hot fluids compared to others during which it «deflates». Upon direct comparison between 6 data sets concerned with different physical settings, it seems to be possible (fig. 3 and table II) to distinguish a few significantly different behaviours associated either (i) with a mere compression (such as occurs for Stromboli, Vesuvius, and a sample compressed in the laboratory), or (ii) with a slip strain, such as it typically occurs in association with faulting or with diurnal thermal rock deformation.
A concise threefold illustration is given: (i) of climate change on the gigayear (Ga) time scale ... more A concise threefold illustration is given: (i) of climate change on the gigayear (Ga) time scale through the nanosecond (nsec) time scale, (ii) of the role of the performance of solid materials, concerning both manmade and natural structures with reference to security, and (iii) of the exploitation of the electrostatic energy of the atmospheric electrical circuit—which is an enormous reservoir of natural “clean” energy. Several unfortunate misunderstandings are highlighted that bias the present generally agreed beliefs. The typical natural pace of the Earth’s “electrocardiogram”, ~27.4 Ma, is such that, at present, for the first time humankind must challenge an Earth’s “heartbeat”. A correct use of sensors is needed to get an efficient monitoring of the ongoing climate change. Both anthropic and natural drivers are to be considered. A brief reminder is given about sensors that ought to monitor solid materials—with application (i) to every kind of machinery, building, viaduct or brid...
We emphasise that large regions, of size comparable to a continent, can eventually, or maybe almo... more We emphasise that large regions, of size comparable to a continent, can eventually, or maybe almost permanently, experience a continuous temporal evolution of crustal stress. Such effects, which have close geodynamic implications, can be effectively monitored by some dense array of Acoustic Emission (AE) sensors. They ought to result correlated with other geophysical inferences, such as sea-level variation, GPS monitoring of continental drift, and seismic and/or volcanic activity. A case history is discussed dealing with the Mediterranean basin and with the central Atlantic Ocean, although the AE database is limited to records collected at two sites alone, one in central Italy and one on Vesuvius.
We emphasise that large regions, of size comparable to a continent, can eventually, or maybe almo... more We emphasise that large regions, of size comparable to a continent, can eventually, or maybe almost permanently, experience a continuous temporal evolution of crustal stress. Such effects, which have close geodynamic implications, can be effectively monitored by some dense array of Acoustic Emission (AE) sensors. They ought to result correlated with other geophysical inferences, such as sea-level variation, GPS monitoring
We monitored the acoustic emission activity of the steel blades to be used for the mirror suspens... more We monitored the acoustic emission activity of the steel blades to be used for the mirror suspension system of a gravitational wave interferometer. We have collected several sets of events getting evidence of a material memory effect (Kaiser effect) associated to the dislocation motion in the steel. This result is more evident when we apply a standard fractal analysis procedure (box counting method) to the timing series of acoustic emission bursts. We conclude that a significant reduction of the emission rate is obtained by applying a few stress cycles to the elastic blades.
Acoustic Emission - Research and Applications, 2013
Several applications of ultrasound monitoring are reported as a standard in the literature and th... more Several applications of ultrasound monitoring are reported as a standard in the literature and they deal with several engineering concerns. However, the method, which is here applied for data handling, for analysis and for physical interpretation, derives from an original procedure 1 which is completely different compared to all previous procedures by other authors that are reported in the literature. The viaduct of the present study is named "Cavalcaferrovia Ostiense" (i.e. "Overpass Ostiense"). It holds three-lanes (altogether 11.5 m wide) in each direction, plus two large sidewalks. It connects the major road "Circonvallazione Ostiense", on its eastern side, with the arterial road "Ostiense" on its western side (figure 1). It is ~ 159 m long, and is located in the Rome neighbourhood named Garbatella. Hence, it is here briefly called "Garbatella bridge" (figure 2, 3 and 4). 2 Its design reminds about a 3-leg spider, with one "leg" on its eastern side. "Side A" is its northern side and "side B" its southern side. Each side is further distinguished, respectively, into its eastern (E) and western (W) segment (figures 3 and 4). It crosses over a four-way railway, i.e. two ways of the Rome urban metro plus two ways of the suburban train Roma-Lido di Ostia. The height of the viaduct with respect to the railway 3 is comparable to the height of a train inside a standard railway tunnel. Every urban train always stops at the Garbatella station, which is very close to the viaduct (figure 1), while every suburban train crosses through it at moderate, although sometimes low, speed. Thermal dilatation is compensated at the two western "legs" of the bridge that can slide longitudinally, while the single eastern "leg" is fixed to its concrete basement. AE monitoring was implemented on December 16 th , 2011 on the occasion of the load test, 4 which was formally carried out on December 17 th , 2011. 5 The total load was made by means of 28 mobile concrete mixers, filled with rubble, everyone of total weight of ~ 3.5 tons. Altogether the load was 9800 kN. The load test was exploited in four steps. During Step 1 the load was symmetric (14 mixers on each side A and B). Step 2 was asymmetric with 14 mixers on side A and no mixer on side B. Step 3 was carried out with 5 mixers over segment A-E and 5 mixers over segment B-W. Step 4 had a load of 8 mixers over segment A-E and 8 mixers over segment BE. Standard monitoring was exploited by means of laser measurements concerning several linear deformations to be compared with model computation. In addition, model computations also 1 The algorithms that are here applied include a few methods that already appeared in a few papers by the authors and co-workers (see below). These procedures are now also a part of a more systematic and compact set of methods for technological applications, which were implemented and patented by G. P. Gregori. Their practical exploitation and applications are in progress at S.M.E.
Acoustic Emission 366 equation is a simple correction that introduces in some approximate way the... more Acoustic Emission 366 equation is a simple correction that introduces in some approximate way the intrinsic nonvanishing volume of a gas molecule. This simple correction, however, can only justify some metastable trend of a gas-liquid mixed system, while a correct description of its equation-ofstate must unavoidably appeal to quantum phenomena. Owing to this same reason, classical electromagnetism alone (Maxwell laws, Faraday, Coulomb, Ampère, Gauss, etc.) has never permitted the exploitation of modern electronics, which rather relies on solid state physics. Quantum bonds play a key role. Quantum phenomena are a fundamental aspect of natural reality. They can even be managed by avoiding formal reference to the Schrödinger equation, Hilbert spaces, Feynman graphs, etc. The cleavage plane of a crystal-hence the ageing of a material-shall never be justified by any model based on "continuity", rather it m u s t r e l y o n a t o m i c b o n d s. A t o m s a r e incompatible with "infinitesimal" quantities, hence with "continuity" (in its strict sense of mathematical analysis). "Homogeneity" is an additional abstraction aimed at fitting the requirements for "simplicity". It correctly applies to manmade structures. But-when dealing with subsystems of the natural environment-it can be applied only within suitable approximations. "Homogeneity" is closely related to the damping of "elastic" waves, which can be propagated through a medium only as far as the wavelength is larger than the mean gaps in the material (these gaps violate homogeneity and continuity). 1 The present paper deals with records of acoustic emission (AE) typically inside a manmade structure-such as a machinery, a building, a bridge, a pipeline, a dam, a rail or road embankment. But AE monitoring can also be carried out in the field, for monitoring crustal stress, volcanic precursors, land slide hazards, etc. As a standard every application is biased by some perturbations that affect the raw AE records. Therefore, a few somewhat different criteria are required while approaching data analysis and interpretation in every specific application. Upon concrete exploitation of this whole approach, the results were found to be heuristically very effective for different algorithms, when they are comparatively applied to different physical systems-either in the laboratory or in the field. The comparison between the different applications resulted very useful for understanding the physics of phenomena that-when considered in every single application alone-could be hardly understood. The present discussion refers therefore to AE records measured both in the laboratory and/or in the field. In general, the intensity of the measured AE signal depends (i) on the intensity of its primary original (either known or unknown) source, and (ii) on the damping of the signalhence on the acoustic impedance, which is different for different probes, and for different AE frequencies, temperatures, etc. Let us recall that the acoustic impedance Z = V of a 1 Communication between different scientific communities is important. A specification on terms is therefore important. Consider a sample of matter, and an energy input to it. If the input and output energies are compared with each other, it is found that some energy was lost. Therefore, it is claimed that some energy has been "absorbed", or that the signal has been "damped" in the process, or that some energy has been "radiated" outside by "scattering loss", or it was released by any other speculated mechanism, etc. All these terms are equivalent in Earth's sciences. In other scientific communities specific "technical" distinctions eventually result from undeclared agreements. This evidently seems to be a matter of semantics, while it has little concern when dealing with the scientific interpretation of phenomena. Engineers distinguish damping and absorption, while this distinction has less meaning to Earth's scientists. www.intechopen.com AE for Monitoring Materials Stress and Ageing 367 material is defined as the product of its density and its acoustic velocity V. This is important for the determination of wave transmission and reflection at the boundary of two materials, for assessing the wave absorption, and for designing ultrasonic transducers. In the last respect, however, it should be pointed out that laboratory measurements are easily carried out in a liquid. For instance, one can measure the acoustic impedance inside water and determine its dependence on temperature, frequency, pressure, etc. In contrast, this is impossible in the case of most solid media. The reason is that the propagation of an "elastic wave" inside a solid object-hence its apparent acoustic impedance-is critically controlled by the geometrical shape of the body, due to wave reflection (and refraction) across the outer boundaries of the object. In the case of water these measurements are carried out inside a pool, with an AE source located at its centre. But this is not possible for a solid medium.
Continuous Acoustic Emission (AE) records are being regularly collected at a site in central Ital... more Continuous Acoustic Emission (AE) records are being regularly collected at a site in central Italy, which was recently severely stricken by earthquakes, and which is presently experiencing the release of frequent sounds originated underground. Different kinds of analyses were carried out, including fractal properties. They revealed intriguing correlations with other geodynamic events occurring in the entire Italian area during the
Acoustic Emissions (AE) allow for clear assessment of the times when AE sources appear 3D distrib... more Acoustic Emissions (AE) allow for clear assessment of the times when AE sources appear 3D distributed in space, envisaging a likely origin by hot fluid diffusion through rock pores, in contrast to times when AE sources denote some more 2D than mere 3D spatial distribution, envisaging an origin by micro-cracks, much like e.g. along a cleavage plane of a crystal. Hence, the AE recorded on a dyke of a volcano recognize the role of hot fluids (having great mobility underground) compared to the role of plutonic intrusions (producing cracks, due to the extremely low mobility of magma underground). AE provide per se with a high sensitivity and time resolution, and recognise inflation and deflation times. AE ought to be correlated with soil degassing and topographical micro-deformations. In contrast, seismic monitoring has a much lower time resolution, as it is concerned with time- and energy-integrated effects, which appear likely to be triggered by the weight of the edifice. Vesuvius is a...
The subject is reviewed, notwithstanding the existence of a number of disagreeing and/or controve... more The subject is reviewed, notwithstanding the existence of a number of disagreeing and/or controversial results found in the literature. First, a brief critical reexamination of the methodology is presented. Second, it is attempted to put the results, or partial conclusions, by different authors, using different methods and referring to different geographical regions, into a working scheme. This is done by investigating, as far as possible, the relationships between the electrical conductivity information and other types of geophysical and geological information for each geographical area investigated. It appears almost impossible to draw general conclusions that hold for the entire Earth. Conclusions are given for those areas with some very well-defined geomorphological characters. Unfortunately, the available investigations still appear to give a poor coverage of several types of geographic areas with specific tectonic characteristics, and certainly the scientific coverage by electromagnetic methods of investigation cannot be compared with those available today from seismological methods. Investigating the electrical conductivity structure of the lower crust certainly opens relevant heuristic possibilities, but there appears to be a great need both for a ref'mement in the basic methodology, and for a better coverage of the investigated areas.
Thank you for your interest to our paper. In the article we tried to show that anomalies of acous... more Thank you for your interest to our paper. In the article we tried to show that anomalies of acoustic emission which we observe in Kamchatka in fair weather conditions are determined by rock deformations at the point of emission registration. In order to do that, we make simultaneous registration of rock deformations and of acoustic emission. Rock deformations may be determined both by strong remote earthquake preparation and by local effects at the point of observations. We would like to emphasize that rocks in which we register signals are sedimentary ones. According to the data of well-drilling,
The prevailing view that radioactive decay is the major thermal source for the interior of the pl... more The prevailing view that radioactive decay is the major thermal source for the interior of the planet may create limitations in geophysical modeling efforts. New theoretical insights by Gregori 2002 [1] provide for an electrical source from the coremantle-boundary (CMB) by a tide-driven (TD) geodynamo which is enhanced by various solar induction processes. Joule heating at density boundaries within the upper mantle and base of the lithosphere from CMB electrical emanations may provide some of the hotspot energy for upper mantle melts and associated magmatism driving seafloor spreading and lithospheric rupture. Estimates of the total budget of the endogenous energy of the Earth supporting the electrical hotspot hypothesis are as follows [1].
The seismic sequence in Central Italy that started in August 2016 and is still in progress in Feb... more The seismic sequence in Central Italy that started in August 2016 and is still in progress in February 2017is investigated like a pilot-study in order to focus on a multidisciplinary perspective for a realistic seismic hazard mitigation and management. A clear distinction has to be made with the “bottom-up” approach which is typical of a geologist or of a seismologist, who investigate phenomena after the occurrence of an earthquake, and upon consideration either of a subset of known phenomena – or of “all” them that are available and that preceded every given shock. Statisticians, altogether with seismologists, apply a formally rigorous and careful approach, based on complicated algorithms etc. Their rigorous approach is certainly indicative and useful for hazard management, unlike every less rigorous statistical analysis that cannot be comparably reliable. In fact, the boundary is not always clearly stated between an “implicit suitable assumption” and logical rigor. A first paper (...
American Journal of Engineering and Applied Sciences, 2021
endogenous energy. An additional gauge can be, maybe, represented by the microorganisms that are ... more endogenous energy. An additional gauge can be, maybe, represented by the microorganisms that are endemically generated at ocean floors that can perhaps justify the time evolution of pathogens maybe also some pandemics. In fact, the mutation of deep ocean biota can be, perhaps, related to the evolution of pathogens that since several decades are well-known to require the updating of all vaccines. In addition, these mutations could also be the possible cause of unprecedented pandemics, that perhaps might even impact at a possibly increasing frequency. An improved capability to detect environmental changes with a higher time-resolution is a prerequisite for understanding and managing also these disquieting and unprecedented threats.
American Journal of Engineering and Applied Sciences, 2021
A more detailed summary is given in the last part (1/4th) of the Introduction. An anomalous perio... more A more detailed summary is given in the last part (1/4th) of the Introduction. An anomalous period is in progress, characterized by a very intense release of endogenous energy from the Earth. The cause is an ongoing heartbeat of the Earth's electrocardiogram. Humankind's history spans a much shorter duration. Hence, at present the humans are going to face an unprecedented challenge, maybe even concerning survival. The duration of the climate anomaly of an Earth's heartbeat is a few Ma. The challenge is to avoid that humankind is going toward extinction. The paper attempts to give a general-and largely original and substantially advanced-perspective of Earth's phenomena. As far as possible, the approach is top-down, i.e., start from known laws and infer expected observations-unlike the more usual bottom-up viewpoint, i.e., start from observations and seek regularities. The present text is devoted to applied scientists. The overall scenario is much more focused and precise than standard treatments. The target of the paper is concerned with the possible actions that can-and must-be implemented in order to face this unprecedented challenge-rather than being concerned with a critical discussion and comparison with the present "generally agreed" geophysical models reported in the literature. In particular, the exploitation is considered of a huge reservoir of natural and clean energy. The central focus of the present paper is the exploitation of the electrostatic energy of the atmospheric electrical circuit, which is a clean and almost inexhaustible free source. It should be stressed that-as it has been proven by quantitative and precise observations-the CO2 pollution of anthropic origin provides an irrelevant-or maybe even a negligible-contribution to climate change. Climate change is, rather, caused by the natural, violent, ongoing exhalation of endogenous energy. This anomaly is going to be manifested, perhaps, by an eventual ever-increasing intensity of phenomena-including seismic and volcanic activity, energy and dynamics on the oceans and atmosphere, greater excursions with respect to the mild climate and a (presently unmonitored) change of endemic microorganism generation on the ocean floors (maybe even affecting pandemics). This study is an attempt to synthesize a wide multidisciplinary scenario, as far as possible by a limited number of pages. The purpose is only to start a much more extensive and profound discussion, that-as far as the geophysical items are concerned-is the object of more extensive studies (in preparation).
Acoustic Emissions (AE) are effective for monitoring ground deformation and temporal variation of... more Acoustic Emissions (AE) are effective for monitoring ground deformation and temporal variation of its porosity. AE are complementary to seismic information, related to the same area, though AE and earthquakes focus on observational evidence concerned with substantially different space-and timescales. AE information is pertinent (i) either for geodynamically stable areas, where it probes the diurnal thermal and/or tidal deformation, (ii) or for seismic areas where it provides some as yet unexploited precursors, (iii) or for volcanic areas, where it appears capable of recognising precursors originated by some hot fluid that penetrates by diffusion into rock pores, from those associated with eventual plutonic magma intrusions, (iv) and also for monitoring periods of time during which a volcano is «inflated» by underground hot fluids compared to others during which it «deflates». Upon direct comparison between 6 data sets concerned with different physical settings, it seems to be possible (fig. 3 and table II) to distinguish a few significantly different behaviours associated either (i) with a mere compression (such as occurs for Stromboli, Vesuvius, and a sample compressed in the laboratory), or (ii) with a slip strain, such as it typically occurs in association with faulting or with diurnal thermal rock deformation.
A concise threefold illustration is given: (i) of climate change on the gigayear (Ga) time scale ... more A concise threefold illustration is given: (i) of climate change on the gigayear (Ga) time scale through the nanosecond (nsec) time scale, (ii) of the role of the performance of solid materials, concerning both manmade and natural structures with reference to security, and (iii) of the exploitation of the electrostatic energy of the atmospheric electrical circuit—which is an enormous reservoir of natural “clean” energy. Several unfortunate misunderstandings are highlighted that bias the present generally agreed beliefs. The typical natural pace of the Earth’s “electrocardiogram”, ~27.4 Ma, is such that, at present, for the first time humankind must challenge an Earth’s “heartbeat”. A correct use of sensors is needed to get an efficient monitoring of the ongoing climate change. Both anthropic and natural drivers are to be considered. A brief reminder is given about sensors that ought to monitor solid materials—with application (i) to every kind of machinery, building, viaduct or brid...
We emphasise that large regions, of size comparable to a continent, can eventually, or maybe almo... more We emphasise that large regions, of size comparable to a continent, can eventually, or maybe almost permanently, experience a continuous temporal evolution of crustal stress. Such effects, which have close geodynamic implications, can be effectively monitored by some dense array of Acoustic Emission (AE) sensors. They ought to result correlated with other geophysical inferences, such as sea-level variation, GPS monitoring of continental drift, and seismic and/or volcanic activity. A case history is discussed dealing with the Mediterranean basin and with the central Atlantic Ocean, although the AE database is limited to records collected at two sites alone, one in central Italy and one on Vesuvius.
We emphasise that large regions, of size comparable to a continent, can eventually, or maybe almo... more We emphasise that large regions, of size comparable to a continent, can eventually, or maybe almost permanently, experience a continuous temporal evolution of crustal stress. Such effects, which have close geodynamic implications, can be effectively monitored by some dense array of Acoustic Emission (AE) sensors. They ought to result correlated with other geophysical inferences, such as sea-level variation, GPS monitoring
We monitored the acoustic emission activity of the steel blades to be used for the mirror suspens... more We monitored the acoustic emission activity of the steel blades to be used for the mirror suspension system of a gravitational wave interferometer. We have collected several sets of events getting evidence of a material memory effect (Kaiser effect) associated to the dislocation motion in the steel. This result is more evident when we apply a standard fractal analysis procedure (box counting method) to the timing series of acoustic emission bursts. We conclude that a significant reduction of the emission rate is obtained by applying a few stress cycles to the elastic blades.
Acoustic Emission - Research and Applications, 2013
Several applications of ultrasound monitoring are reported as a standard in the literature and th... more Several applications of ultrasound monitoring are reported as a standard in the literature and they deal with several engineering concerns. However, the method, which is here applied for data handling, for analysis and for physical interpretation, derives from an original procedure 1 which is completely different compared to all previous procedures by other authors that are reported in the literature. The viaduct of the present study is named "Cavalcaferrovia Ostiense" (i.e. "Overpass Ostiense"). It holds three-lanes (altogether 11.5 m wide) in each direction, plus two large sidewalks. It connects the major road "Circonvallazione Ostiense", on its eastern side, with the arterial road "Ostiense" on its western side (figure 1). It is ~ 159 m long, and is located in the Rome neighbourhood named Garbatella. Hence, it is here briefly called "Garbatella bridge" (figure 2, 3 and 4). 2 Its design reminds about a 3-leg spider, with one "leg" on its eastern side. "Side A" is its northern side and "side B" its southern side. Each side is further distinguished, respectively, into its eastern (E) and western (W) segment (figures 3 and 4). It crosses over a four-way railway, i.e. two ways of the Rome urban metro plus two ways of the suburban train Roma-Lido di Ostia. The height of the viaduct with respect to the railway 3 is comparable to the height of a train inside a standard railway tunnel. Every urban train always stops at the Garbatella station, which is very close to the viaduct (figure 1), while every suburban train crosses through it at moderate, although sometimes low, speed. Thermal dilatation is compensated at the two western "legs" of the bridge that can slide longitudinally, while the single eastern "leg" is fixed to its concrete basement. AE monitoring was implemented on December 16 th , 2011 on the occasion of the load test, 4 which was formally carried out on December 17 th , 2011. 5 The total load was made by means of 28 mobile concrete mixers, filled with rubble, everyone of total weight of ~ 3.5 tons. Altogether the load was 9800 kN. The load test was exploited in four steps. During Step 1 the load was symmetric (14 mixers on each side A and B). Step 2 was asymmetric with 14 mixers on side A and no mixer on side B. Step 3 was carried out with 5 mixers over segment A-E and 5 mixers over segment B-W. Step 4 had a load of 8 mixers over segment A-E and 8 mixers over segment BE. Standard monitoring was exploited by means of laser measurements concerning several linear deformations to be compared with model computation. In addition, model computations also 1 The algorithms that are here applied include a few methods that already appeared in a few papers by the authors and co-workers (see below). These procedures are now also a part of a more systematic and compact set of methods for technological applications, which were implemented and patented by G. P. Gregori. Their practical exploitation and applications are in progress at S.M.E.
Acoustic Emission 366 equation is a simple correction that introduces in some approximate way the... more Acoustic Emission 366 equation is a simple correction that introduces in some approximate way the intrinsic nonvanishing volume of a gas molecule. This simple correction, however, can only justify some metastable trend of a gas-liquid mixed system, while a correct description of its equation-ofstate must unavoidably appeal to quantum phenomena. Owing to this same reason, classical electromagnetism alone (Maxwell laws, Faraday, Coulomb, Ampère, Gauss, etc.) has never permitted the exploitation of modern electronics, which rather relies on solid state physics. Quantum bonds play a key role. Quantum phenomena are a fundamental aspect of natural reality. They can even be managed by avoiding formal reference to the Schrödinger equation, Hilbert spaces, Feynman graphs, etc. The cleavage plane of a crystal-hence the ageing of a material-shall never be justified by any model based on "continuity", rather it m u s t r e l y o n a t o m i c b o n d s. A t o m s a r e incompatible with "infinitesimal" quantities, hence with "continuity" (in its strict sense of mathematical analysis). "Homogeneity" is an additional abstraction aimed at fitting the requirements for "simplicity". It correctly applies to manmade structures. But-when dealing with subsystems of the natural environment-it can be applied only within suitable approximations. "Homogeneity" is closely related to the damping of "elastic" waves, which can be propagated through a medium only as far as the wavelength is larger than the mean gaps in the material (these gaps violate homogeneity and continuity). 1 The present paper deals with records of acoustic emission (AE) typically inside a manmade structure-such as a machinery, a building, a bridge, a pipeline, a dam, a rail or road embankment. But AE monitoring can also be carried out in the field, for monitoring crustal stress, volcanic precursors, land slide hazards, etc. As a standard every application is biased by some perturbations that affect the raw AE records. Therefore, a few somewhat different criteria are required while approaching data analysis and interpretation in every specific application. Upon concrete exploitation of this whole approach, the results were found to be heuristically very effective for different algorithms, when they are comparatively applied to different physical systems-either in the laboratory or in the field. The comparison between the different applications resulted very useful for understanding the physics of phenomena that-when considered in every single application alone-could be hardly understood. The present discussion refers therefore to AE records measured both in the laboratory and/or in the field. In general, the intensity of the measured AE signal depends (i) on the intensity of its primary original (either known or unknown) source, and (ii) on the damping of the signalhence on the acoustic impedance, which is different for different probes, and for different AE frequencies, temperatures, etc. Let us recall that the acoustic impedance Z = V of a 1 Communication between different scientific communities is important. A specification on terms is therefore important. Consider a sample of matter, and an energy input to it. If the input and output energies are compared with each other, it is found that some energy was lost. Therefore, it is claimed that some energy has been "absorbed", or that the signal has been "damped" in the process, or that some energy has been "radiated" outside by "scattering loss", or it was released by any other speculated mechanism, etc. All these terms are equivalent in Earth's sciences. In other scientific communities specific "technical" distinctions eventually result from undeclared agreements. This evidently seems to be a matter of semantics, while it has little concern when dealing with the scientific interpretation of phenomena. Engineers distinguish damping and absorption, while this distinction has less meaning to Earth's scientists. www.intechopen.com AE for Monitoring Materials Stress and Ageing 367 material is defined as the product of its density and its acoustic velocity V. This is important for the determination of wave transmission and reflection at the boundary of two materials, for assessing the wave absorption, and for designing ultrasonic transducers. In the last respect, however, it should be pointed out that laboratory measurements are easily carried out in a liquid. For instance, one can measure the acoustic impedance inside water and determine its dependence on temperature, frequency, pressure, etc. In contrast, this is impossible in the case of most solid media. The reason is that the propagation of an "elastic wave" inside a solid object-hence its apparent acoustic impedance-is critically controlled by the geometrical shape of the body, due to wave reflection (and refraction) across the outer boundaries of the object. In the case of water these measurements are carried out inside a pool, with an AE source located at its centre. But this is not possible for a solid medium.
Continuous Acoustic Emission (AE) records are being regularly collected at a site in central Ital... more Continuous Acoustic Emission (AE) records are being regularly collected at a site in central Italy, which was recently severely stricken by earthquakes, and which is presently experiencing the release of frequent sounds originated underground. Different kinds of analyses were carried out, including fractal properties. They revealed intriguing correlations with other geodynamic events occurring in the entire Italian area during the
Acoustic Emissions (AE) allow for clear assessment of the times when AE sources appear 3D distrib... more Acoustic Emissions (AE) allow for clear assessment of the times when AE sources appear 3D distributed in space, envisaging a likely origin by hot fluid diffusion through rock pores, in contrast to times when AE sources denote some more 2D than mere 3D spatial distribution, envisaging an origin by micro-cracks, much like e.g. along a cleavage plane of a crystal. Hence, the AE recorded on a dyke of a volcano recognize the role of hot fluids (having great mobility underground) compared to the role of plutonic intrusions (producing cracks, due to the extremely low mobility of magma underground). AE provide per se with a high sensitivity and time resolution, and recognise inflation and deflation times. AE ought to be correlated with soil degassing and topographical micro-deformations. In contrast, seismic monitoring has a much lower time resolution, as it is concerned with time- and energy-integrated effects, which appear likely to be triggered by the weight of the edifice. Vesuvius is a...
The subject is reviewed, notwithstanding the existence of a number of disagreeing and/or controve... more The subject is reviewed, notwithstanding the existence of a number of disagreeing and/or controversial results found in the literature. First, a brief critical reexamination of the methodology is presented. Second, it is attempted to put the results, or partial conclusions, by different authors, using different methods and referring to different geographical regions, into a working scheme. This is done by investigating, as far as possible, the relationships between the electrical conductivity information and other types of geophysical and geological information for each geographical area investigated. It appears almost impossible to draw general conclusions that hold for the entire Earth. Conclusions are given for those areas with some very well-defined geomorphological characters. Unfortunately, the available investigations still appear to give a poor coverage of several types of geographic areas with specific tectonic characteristics, and certainly the scientific coverage by electromagnetic methods of investigation cannot be compared with those available today from seismological methods. Investigating the electrical conductivity structure of the lower crust certainly opens relevant heuristic possibilities, but there appears to be a great need both for a ref'mement in the basic methodology, and for a better coverage of the investigated areas.
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