scholarly journals Multiscale Analysis of DInSAR Measurements for Multi-Source Investigation at Uturuncu Volcano (Bolivia)

2019 ◽  
Vol 11 (6) ◽  
pp. 703 ◽  
Author(s):  
Andrea Barone ◽  
Maurizio Fedi ◽  
Pietro Tizzani ◽  
Raffaele Castaldo
Keyword(s):  
Multiscale Analysis ◽  
Cross Correlation ◽  
Ground Deformation ◽  
Vertical Component ◽  
Central Zone ◽  
Time Interval ◽  
Volcanic Complex ◽  
Magma Body ◽  
Deep Source ◽  
Good Agreement

Uturuncu volcano (southwestern Bolivia) is localized within one of the largest updoming volcanic zones, the Altiplano Puna Volcanic Complex (APVC). In several geodetic studies the observed uplift phenomenon is analyzed and modeled by considering a deep source, related to the Altiplano Puna Magma Body (APMB). In this framework, we perform a multiscale analysis on the 2003–2010 ENVISAT satellite data to investigate the existence of a multi-source scenario for this region. The proposed analysis is based on Cross-correlation and Multiridge method, pointing out the spatial and temporal multiscale properties of the deformation field. In particular, we analyze the vertical component of ground deformation during two time interval: within the 2005–2008 time interval an inflating source at 18.7 km depth beneath the central zone of the APVC is retrieved; this result is in good agreement with those proposed by several authors for the APMB. Between August 2006 and February 2007, we identify a further inflating source at 4.5 km depth, beneath Uturuncu volcano; the existence of this latter, located just below the 2009–2010 seismic swarm, is supported by petrological, geochemical, and geophysical evidence, indicating as a possible interpretative scenario the action of shallow, temporarily trapped fluids.

scholarly journals Anisotropy, repeating earthquakes, and seismicity associated with the 2008 eruption of Okmok volcano, Alaska

2021 ◽  
Author(s):  
J Johnson ◽  
S Prejean ◽  
Martha Savage ◽  
John Townend
Keyword(s):  
Cross Correlation ◽  
Normal Fault ◽  
Processing Parameters ◽  
Temporal Variations ◽  
Geothermal Field ◽  
Double Difference ◽  
Magma Body ◽  
Seismic Properties ◽  
Northern Portion ◽  
Okmok Volcano

We use shear wave splitting (SWS) analysis and double-difference relocation to examine temporal variations in seismic properties prior to and accompanying magmatic activity associated with the 2008 eruption of Okmok volcano, Alaska. Using bispectrum cross-correlation, a multiplet of 25 earthquakes is identified spanning five years leading up to the eruption, each event having first motions compatible with a normal fault striking NE-SW. Cross-correlation differential times are used to relocate earthquakes occurring between January 2003 and February 2009. The bulk of the seismicity prior to the onset of the eruption on 12 July 2008 occurred southwest of the caldera beneath a geothermal field. Earthquakes associated with the onset of the eruption occurred beneath the northern portion of the caldera and started as deep as 13 km. Subsequent earthquakes occurred predominantly at 3 km depth, coinciding with the depth at which the magma body has been modeled using geodetic data. Automated SWS analysis of the Okmok catalog reveals radial polarization outside the caldera and a northwest-southeast polarization within. We interpret these polarizations in terms of a magma reservoir near the center of the caldera, which we model with a Mogi point source. SWS analysis using the same input processing parameters for each event in the multiplet reveals no temporal changes in anisotropy over the duration of the multiplet, suggesting either a short-term or small increase in stress just before the eruption that was not detected by GPS, or eruption triggering by a mechanism other than a change of stress in the system. © 2010 by the American Geophysical Union.

scholarly journals New Results on the Motions of Asteroids in Resonances

1992 ◽  
Vol 152 ◽  
pp. 145-152 ◽  
Author(s):  
R. Dvorak
Keyword(s):  
Initial Conditions ◽  
Numerical Study ◽  
Equations Of Motion ◽  
Close Approach ◽  
Integration Time ◽  
Time Interval ◽  
Time Intervals ◽  
3 Dimensional ◽  
Special Cases ◽  
Good Agreement

In this article we present a numerical study of the motion of asteroids in the 2:1 and 3:1 resonance with Jupiter. We integrated the equations of motion of the elliptic restricted 3-body problem for a great number of initial conditions within this 2 resonances for a time interval of 104 periods and for special cases even longer (which corresponds in the the Sun-Jupiter system to time intervals up to 106 years). We present our results in the form of 3-dimensional diagrams (initial a versus initial e, and in the z-axes the highest value of the eccentricity during the whole integration time). In the 3:1 resonance an eccentricity higher than 0.3 can lead to a close approach to Mars and hence to an escape from the resonance. Asteroids in the 2:1 resonance with Jupiter with eccentricities higher than 0.5 suffer from possible close approaches to Jupiter itself and then again this leads in general to an escape from the resonance. In both resonances we found possible regions of escape (chaotic regions), but only for initial eccentricities e > 0.15. The comparison with recent results show quite a good agreement for the structure of the 3:1 resonance. For motions in the 2:1 resonance our numeric results are in contradiction to others: high eccentric orbits are also found which may lead to escapes and consequently to a depletion of this resonant regions.

scholarly journals Recharge Impulse Spreading in Western Carpathian’s Mountainous Fissure–Karst Aquifer

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 763 ◽  
Author(s):  
Malík ◽  
Coplák ◽  
Kuvik ◽  
Švasta
Keyword(s):  
Water Temperature ◽  
Karst Aquifer ◽  
Large Body ◽  
Vertical Component ◽  
Groundwater Table ◽  
Time Shift ◽  
Winter Period ◽  
Time Interval ◽  
Spring Discharge ◽  
Groundwater Flux

: Foreseen construction of a highway tunnel in the northern part of the Veľká Fatra Mts. (Slovakia) triggered the need for extensive hydrogeological investigations. The projected tunnel axis would cut through a large body buildup of Middle Triassic carbonate rocks. Dolomites and limestones with fissure–karstic permeability are surrounded by less-permeable marls, so that all springs dewatering this uplifted plate of carbonates are found above the erosion base on its edges. Detailed, hourly-based discharge monitoring of all four major springs was performed during the spring and summer period of 2014. In the meantime, groundwater table observations in two boreholes, located in the center of the fissure–karst aquifer, were run in the same time interval. Based on air temperature and precipitation records, the 2013–2014 winter period was practically without snow cover. In the middle of March 2014, an intense rainfall event caused a sudden rise of the groundwater table in the TK-04 borehole located in the southern part of the carbonate plate. Spreading of this singular hydraulic impulse throughout the structure was differently registered at individual springs within the time shift span of 1.38 to 65.25 days. Groundwater level rise of 0.40 m in the TK-04 borehole was postponed in 5.33 days. The response time of spring discharge to sudden groundwater table rise within the structure occurred later at springs with a higher water temperature. Water temperature differences between individual springs were still within the 2.46 °C narrow interval (5.57–8.03 °C). The vertical component of groundwater flux should play an important role even in a relatively simple, plate-shaped mountainous karstic aquifer fully uplifted above the erosional base, as was the case of the investigated Kopa Mt. hydrogeological structure.

Identification of the Velocity, Thickness, and Interfacial Roughness of Coating Using Full Time-Domain URCPS: Cross-Correlation-Based Inverse Problem

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Zhiyuan Ma ◽  
Li Lin ◽  
Shijie Jin ◽  
Mingkai Lei
Keyword(s):  
Time Domain ◽  
Measurement Errors ◽  
Cross Correlation ◽  
Inversion Method ◽  
Full Time ◽  
Interfacial Roughness ◽  
Measured Velocity ◽  
Detection Frequency ◽  
Relative Errors ◽  
Good Agreement

Aiming at characterizing interfacial roughness of thin coatings with unknown sound velocity and thickness, we derive a full time-domain ultrasonic reflection coefficient phase spectrum (URCPS) as a function of interfacial roughness based on the phase screen approximation theory. The constructed URCPS is used to determine the velocity, thickness, and interfacial roughness of specimens through the cross-correlation algorithm. The effect of detection frequency on the roughness measurement is investigated through the finite element method. A series of simulations were implemented on Ni-coating specimens with a thickness of 400 μm and interfacial roughness of 1.9–39.8 μm. Simulation results indicated that the measurement errors of interfacial roughness were less than 10% when the roughness satisfies the relationship of Rq = 1.6–10.0%λ. The measured velocity and thicknesses were in good agreement with those imported in simulation models with less than 9.3% error. Ultrasonic experiments were carried out on two Ni-coating specimens through a flat transducer with an optimized frequency of 15 MHz. Compared with the velocities measured by time-of-flight (TOF) method, the relative errors of inversed velocities were all less than 10%. The inversed thicknesses were in good agreement with those observed by optical microscopy with less than 10.9% and 7.6% error. The averaged interfacial roughness determined by the ultrasonic inversion method was 16.9 μm and 30.7 μm, respectively. The relative errors were 5.1% and 2.0% between ultrasonic and confocal laser scanning microscope (CLSM) method, respectively.

A Tubeless V-Trough Solar Concentrator

1986 ◽  
Vol 10 (3) ◽  
pp. 135-140
Author(s):  
M. Issa Abdulhadi
Keyword(s):  
Experimental Investigation ◽  
Energy Balance ◽  
Analytical Approach ◽  
Mathematical Expression ◽  
Time Interval ◽  
Solar Concentrator ◽  
Late Afternoon ◽  
Heating And Cooling ◽  
Reliable Source ◽  
Good Agreement

An analytical, experimental investigation of the thermal performance of a tubeless V-trough concentrator has been carried out. Considering the energy balance on the receiver plate, a mathematical expression is developed from which the receiver plate mean temperature can be evaluated for each time interval. The good agreement between the experimental results and the analytical predictions indicate that the construction of a tubeless absorber panel might be valuable and the analytical approach might have the potential for further extensions. It has been found, according to the expermental investigation, that the fluid outlet temperatures vary between 69°C and 91 °C from 10:30 a.m. on up to the termination of operation in the late afternoon. This qualifies the V-trough to be a reliable source for providing temperatures in this range that can be utilized in heating and cooling applications.

scholarly journals Reliability Evaluation of the Data Acquisition Potential of a Low-Cost Climatic Network for Applications in Agriculture

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6597
Author(s):  
Sergio Trilles ◽  
Pablo Juan ◽  
Carlos Díaz-Avalos ◽  
Sara Ribeiro ◽  
Marco Painho
Keyword(s):  
Data Acquisition ◽  
Strong Influence ◽  
Cross Correlation ◽  
Low Cost ◽  
Central Zone ◽  
Climatic Conditions ◽  
The Other ◽  
Sensor Nodes ◽  
Disease Models ◽  
Similarity Analysis

Temperature, humidity and precipitation have a strong influence on the generation of diseases in different crops, especially in vine. In recent years, advances in different disciplines have enabled the deployment of sensor nodes on agricultural plots. These sensors are characterised by a low cost and so the reliability of the data obtained from them can be compromised, as they are built from low-confidence components. In this research, two studies were carried out to determine the reliability of the data obtained by different SEnviro nodes installed in vineyards. Two networks of meteorological stations were used to carry out these studies, one official and the other professional. The first study was based on calculating the homogenisation of the data, which was performed using the Climatol tool. The second study proposed a similarity analysis using cross-correlation. The results showed that the low-cost node can be used to monitor climatic conditions in an agricultural area in the central zone of the province of Castelló (Spain) and to obtain reliable observations for use in previously published fungal disease models.

Structural Integrity Assessment for Various Failure Modes Using a Risk-Based Maintenance Method

2004 ◽  
Author(s):  
Hiroyuki Horikawa ◽  
Masaki Yoshikawa ◽  
Nobuo Takasu
Keyword(s):  
Failure Modes ◽  
Structural Integrity ◽  
Ground Deformation ◽  
Degradation Mechanism ◽  
Risk Level ◽  
Integrity Assessment ◽  
Evaluation Approach ◽  
Actual Damage ◽  
Maintenance Plan ◽  
Good Agreement

In this paper, a newly developed system called RBM (Risk-Based Maintenance) is presented. The system is used to describe the structural integrity of buried pipeline based on the index of risk that is defined in the product of the failure frequency and the consequence. Various failure modes corresponding to each degradation mechanism are included, and the estimation of failure probability that the external load exceeds the structure resistance is carried out. As the result of trial evaluation compared with the past earthquake incident, it is in good agreement with actual damage of pipeline subjected to liquefaction and large ground deformation. Furthermore, the system enables operators to maintain the structural integrity for service life by providing the most optimized maintenance plan according to the risk level. The features of the quantitative risk evaluation approach and the benefits of the developed RBM system as a means of structural integrity assessment are also discussed.

scholarly journals Modeling Water Balance of Dammed Lakes Using Computer Code Matlab-Simulink/ Modelowanie Bilansu Wodnego Piętrzonych Jezior Za Pomocą Programu Komputerowego Matlab-Simulink

2014 ◽  
Vol 14 (3) ◽  
pp. 5-14
Author(s):  
Ryszard Błażejewski ◽  
Sadżide Murat-Błażejewska ◽  
Martyna Jędrkowiak
Keyword(s):  
Water Balance ◽  
Computer Code ◽  
Water Levels ◽  
Time Interval ◽  
Lake Surface ◽  
Time Intervals ◽  
Matlab Simulink ◽  
Surface Evaporation ◽  
Flow Through ◽  
Good Agreement

Abstract The paper presents a water balance of a flow-through, dammed lake, consisted of the following terms: surface inflow, underground inflow/outflow based on the Dupuit’s equation, precipitation on the lake surface, evaporation from water surface and outflow from the lake at which a damming weir is located. The balance equation was implemented Matlab-Simulink®. Applicability of the model was assessed on the example of the Sławianowskie Lake of surface area 276 ha and mean depth - 6.6 m, Water balances, performed for month time intervals in the hydrological year 2009, showed good agreement for the first three months only. It is concluded that the balancing time interval should be shorter (1 day) to minimize the errors. For calibration purposes, measurements of ground water levels in the vicinity of the lake are also recommended.

scholarly journals A TIME-SEQUENCE AUTORADIOGRAPHIC STUDY OF THE IN VIVO INCORPORATION OF [1, 2-3H]CHOLESTEROL INTO PERIPHERAL NERVE MYELIN

1973 ◽  
Vol 58 (1) ◽  
pp. 42-53 ◽  
Author(s):  
Frank A. Rawlins
Keyword(s):  
Schwann Cell ◽  
Peripheral Nerve ◽  
Myelin Sheath ◽  
Central Zone ◽  
Autoradiographic Study ◽  
Nerve Fibers ◽  
Time Sequence ◽  
Time Interval ◽  
Electron Microscope Autoradiography

A time-sequence study of the incorporation and distribution of cholesterol in peripheral nerve myelin was carried out by electron microscope autoradiography. [1,2-3H]Cholesterol was injected into 10-day old mice and the sciatic nerves were dissected out at 10, 20, 40, 60, 90, 120, and 180 min after the injection. 20 min after injection the higher densities of grains due to the presence of [3H]cholesterol were confined to the outer and inner edges of the myelin sheath. Practically no cholesterol was detected in the midzone of the myelin sheath. 1 ½ h after injection, cholesterol showed a wider distribution within the myelin sheath, the higher densities of grains occurring over the two peripheral myelin bands, each approximately 3,100 Å wide. Cholesterol was also present in the center of the myelin sheath but to a considerably lesser extent. 3 h after injection cholesterol appeared homogeneously distributed within the myelin sheath. Schwann cell and axon compartments were also labeled at each time interval studied beginning 20 min postinjection. These observations indicate that preformed cholesterol enters myelin first and almost simultaneously through the inner and outer edges of the sheath; only after 90 min does the density of labeled cholesterol in the central zone of myelin reach the same density as that in the outer and inner zones. These findings suggest that cholesterol used by the nerve fibers in the formation and maintenance of the myelin sheath enters the lamellae from the Schwann cell cytoplasm and from the axon. The possibility of a bidirectional movement of molecules, i.e. from the Schwann cell to the axon and from the axon to the Schwann cell through the myelin sheath, is noted. The results are discussed in the light of recent observations on the exchange, reutilization, and transaxonal movement of cholesterol.

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