Intelligent system for measuring the level and mass of liquid in fuel tanks and tanks during pitching and tilting

An overview of the existing methods for measuring the liquid level and their disadvantages in the case of surface vibrations is presented. A system for continuous measurement of the mass of liquids in fuel tanks and tanks during rolling and tilting of vehicles and ships, implemented in a level gauge based on intelligent sensors, is proposed. The sensors include a microcontroller with an individual calibration characteristic of the volume-level dependence, taking into account the shape of the tank or fuel tank, and nanosensors built into the intelligent sensor (ID) for measuring density, permittivity and ambient temperature. It is established that the actual metrological characteristics of the ID are significantly higher than the characteristics of traditional sensors. The number and dimensions of the plates of flat capacitors are justified and the scheme of their arrangement on the roof of the tanks is presented. The exclusion of movable elements increased the reliability of operation, simplified maintenance and design requirements of the measuring object. Analytical expressions for calculating the level and mass of the liquid, implemented by the microcontroller, are given. The use of the proposed measurement system with complex computational processing and taking into account corrections for temperature, density, humidity and permittivity of the liquid made it possible to increase the accuracy and stability of the level meter readings. Analytical expressions are derived that relate the liquid level and the output frequency of the generator from the composition of the level gauge.

Mining-Induced Tremors Source Modelling Applying InSAR

<p>Mining exploitation is associated with the occurrence of adverse environmental effects. The most serious of such effects is land subsidence. Although land subsidence can be well predicted and mitigated by several methods, nevertheless, the extraction of mineral deposits is also associated with induced seismicity. The occurrence of seismic events causes ground surface vibrations, land surface displacements and, in many cases, has a negative impact on the safety of surface infrastructure and the inhabitants of endangered areas. Despite this, the issue of induced seismicity is much less recognized and often ignored in the assessment of the negative impacts of mining exploitation.</p><p>Induced seismicity is related to stress changes in the reservoir and surrounding rock mass that may be caused by a variety of mechanisms. Consequently, the patterns of induced seismicity vary greatly over time and space for different fields or events within the same field. It is often difficult to determine the correlation between seismicity and mining precisely because of the lack of data detailing the pattern of exploitation at the various wells. As a result, the source mechanism of mining-induced tremor remains a subject of active research.</p><p>The research aimed to better identify the phenomenon of induced seismicity caused by mining operations. Research has been conducted in the area of underground copper ore mining in Poland. Firstly, we investigate the pre-and post-seismic land-surface movements following 8 mining-induced Mw 3.6-4.8 earthquakes that occurred between 2016 and 2018. We use Sentinel 1 data to derive these movements 2 weeks before and 4 weeks after the mainshock. The results of these studies show that no substantial pre-seismic surface movements are indicating the possibility of a seismic event occurring. However, the co-seismic deformation fields are quite symmetrical, the maximum land subsidence is almost 10 cm and occurs within a few days after the mainshock. In addition, the time series of post-seismic deformation shows a gradual decay and a good correspondence with the post-shock distribution.</p><p>Secondly, we use the Mogi model, assuming the elastic half-space, to invert co-seismic deformation fields and to obtain the source parameters of the mine-induced earthquakes. The spatial distribution of the epicenters indicates a correlation with the fields of mining exploitation. The results also show that the average depth of the hypocenter tremor is approx. 650 m. This corresponds to the depth of the stiff sandstone layers adjacent to the exploration. These layers accumulate the stress of post-exploitation voids. In addition, the modeling results indicate an approx. the volume of the displaced rock layers of 1.2 x 105 m3. This value shows a high correlation with the volume of post-shock troughs determined based on InSAR data.</p><p>The results of this study contribute to research into activities related to mining operations resulting in an induced-earthquake occurrence. This demonstrates InSAR's potential for quasi-constant monitoring of large-scale areas against seismic hazards caused by ongoing mining operations.</p>

Modal Analysis of Selected Measuring Bases and Their Impact on the Recorded Level of Surface Accelerations

In predicting the impact of vibrations propagated in a ground on newly designed construction objects, it is extremely important to reliably measure the time histories of velocity or acceleration at the site of the planned investment. As some studies show, the method of coupling accelerometers and geophones to the ground can affect not only the level of peak particle accelerations (PPA) or peak particle velocities (PPV)—commonly used in this type of evaluation—but also vibration frequency distribution of recorded signals. This makes it difficult to compare and analyze the results obtained by various research teams. Conclusions based on this type of comparison may be wrong. For this reason, it is extremely important that reliable dynamic measurements related to the propagation of ground surface vibrations should be carried out using not only appropriately selected measuring equipment (with the required sensitivity and measurement ranges—both in the time domain and frequency domain), but also the measurement bases/setups used for mounting various types of transducers, whose natural frequencies will be outside the frequency range relevant to the possible impact of vibrations on buildings and human beings inside. The paper presents the results of modal analyses carried out with the use of Ansys Engineering Simulation and 3D Design Software (based on the Finite Element Method) for three different types of measuring bases used to coupling accelerometers to the ground. Measuring bases selected for numerical analyses were in the form of a stiff steel spike of an X-shaped cross section (a measuring base No. 1) and two steel spikes of L-shaped cross-sections (a measuring bases No. 2 and No. 3). In the places of screwed accelerometers (three different types of IEPE/ICP transducers of varying sensitivity and a weight) point masses were attached to the measuring bases. As a result of the analyses, it was possible to determine the impact of individual methods of coupling of accelerometers to the ground on the reliability of recorded ground surface accelerations. Among others it was concluded that in each analyzed case the lowest natural frequencies of the measuring bases with attached accelerometers significantly exceeded 100 Hz. The widest frequency band free of resonance vibrations can be provided by the measuring base No. 3 (L50 × 50 × 5).

Identification of the ground movements caused by mining-induced seismicity with the satellite interferometry

The assessment of the impact of mining-induced seismicity on the natural environment and infrastructure is often limited to the analysis of terrain surface vibrations. However, similar seismic phenomena, like earthquakes, may also imply dislocations and deformations of the rock mass. Such ground movements may occur in areas which are not directly under the influence of the mining. The study of the displacement field caused by mining-induced seismicity is usually carried out with the use of geodetic methods. Classical geodetic measurements provide discrete information about observed ground movements. As a result, they generally do not provide spatially and temporally relevant estimates of the total range and values of ground movements for specific periods of interest. Moreover, mining-induced seismicity causes a severe threat to buildings. That is why, regarding the complexity of the mechanism of occurrence of mining-induced seismicity and their impact on ground movements, this problem remains a substantial research issue. The presented research aimed to analyse the ground movements caused by mining-induced seismicity. The ground displacements were established based on data from Sentinel-1 satellites applying differential interferometric synthetic aperture radar (DInSAR). The results of the investigation in the copper mining area of the Lower Silesia region of Poland revealed that the observed subsidence caused by mining-induced seismicity usually has a shape of a regular ellipse. The radius of these ground movements does not exceed approximately 2–3 km from the mining-induced tremor's epicenter, and the total subsidence reaches ca. 10–20 cm. More than 50 % of the total subsidence is observed on the surface within a few days after the mining tremor occurrence. Furthermore, the deformations of the surface occur when the energy of mining-induced tremor reaches values of the order of 105 J or higher. The presented research can contribute to better identification and evaluation of the mechanism of the rock mass deformation process caused by mining-induced seismicity. In addition, the use of satellite radar interferometry improves the quality of monitoring of these dynamic phenomena significantly. The data retrieved using this method allow for quasi-continuous monitoring of the local subsidence bowls caused by mining-induced seismicity.

On Image Fusion of Ground Surface Vibration for Mapping and Locating Underground Pipeline Leakage: An Experimental Investigation

This paper is concerned with imaging techniques for mapping and locating underground pipeline leakage. Ground surface vibrations induced by the propagating axisymmetric wave can be measured by an array of acoustic/vibration sensors, with the extraction of magnitude information used to determine the position of leak source. A method of connected graph traversal is incorporated into the vibroacoustic technique to obtain the spatial image with better accuracy compared to the conventional magnitude contour plot. Measurements are made on a dedicated cast iron water pipe by an array of seven triaxial geophones. The spectral characteristics of the propagation of leak noise signals from underground water pipes to the ground surface are reported. Furthermore, it is demonstrated that suspicious leakage areas can be readily identified by extracting and fusing the feature patterns at low frequencies where leak noise dominates. The results agree well with the real leakage position in the underground pipeline.

Volume and Frequency-Independent Spreading of Droplets Driven by Ultrasonic Surface Vibration

Many industrial processes depend on the wetting of liquids on various surfaces. Understanding the wetting effects due to ultrasonic vibration could provide a means for changing the behavior of liquids on any surface. In previous studies, low-frequency surface vibrations have been used to alter wetting states of droplets by exciting droplet volume modes. While high-frequency (>20 kHz) surface vibration can also cause droplets to wet or spread on a surface, this effect is relatively uncharacterized. In this study, droplets of various liquids with volumes ranging from 2 to 70 µL were vibrated on hydrophobic-coated (FluoroSyl) glass substrates fixed to a piezoelectric transducer at varying amplitudes and at a range of frequencies between 21 and 42 kHz. The conditions for contact line motion were evaluated, and the change in droplet diameter under vibration was measured. Droplets of all tested liquids initially begin to spread out at a similar surface acceleration level. The results show that the increase in diameter is proportional to the maximum acceleration of the surface. Finally, liquid properties and surface roughness may also produce some secondary effects, but droplet volume and excitation frequency do not significantly change the droplet spreading behavior within the parameter range studied.

Quantifying the Stiffness of Biceps Muscle Using Accelerometer

With increasing awareness of health benefits from incorporating exercise for a more physically active lifestyle, a natural increase in injuries to connective tissues within the body is inevitable. Determining the condition of these tissues by current imaging techniques is expensive, difficult, and not entirely reliable. Using a Modally Hand Impact Hammer and 3D accelerometers, shear wave propagation from surface vibrations of superficial skeletal muscle was measured. The use of accelerometers in this technique contribute some advantages over other techniques. The ability to mount the accelerometers directly to subject area provides greater flexibility for the subject and the investigator. Utilizing this method provides low cost, non-invasive, reliable and repeatable measure of material characteristics. An increase in shear wave propagation and Modulus of Elasticity were observed in 10 subjects as the number of excited muscle fibers within the biceps brachii increased (muscular contraction) and decreased lower than initial resting values post muscular contraction. This technique may prove more practical in clinical settings for swift in-house or on-site assessments of muscle stiffness to help determine the condition. In a broader relationship, this process further demonstrates that techniques developed through mechanical engineering are beneficial to the health and biology fields.