Statistical Analysis on In-situ Material Properties for Aged Cores of Earth-Cored Fill Dams

2016 ◽  
Vol 16 (3) ◽  
pp. 243-256 ◽  
Author(s):  
DongSoon Park ◽  
Jeheon Oh
Keyword(s):  
Statistical Analysis ◽  
Material Properties

scholarly journals Time-Response-Histogram-Based Feature of Magnetic Barkhausen Noise for Material Characterization Considering Influences of Grain and Grain Boundary under In Situ Tensile Test

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2350
Author(s):  
Jia Liu ◽  
Guiyun Tian ◽  
Bin Gao ◽  
Kun Zeng ◽  
Yongbing Xu ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Tensile Stress ◽  
Material Properties ◽  
Ferromagnetic Material ◽  
Silicon Steel ◽  
Time Response ◽  
Barkhausen Noise ◽  
Time Interval ◽  
Magnetic Barkhausen Noise

Stress is the crucial factor of ferromagnetic material failure origin. However, the nondestructive test methods to analyze the ferromagnetic material properties’ inhomogeneity on the microscopic scale with stress have not been obtained so far. In this study, magnetic Barkhausen noise (MBN) signals on different silicon steel sheet locations under in situ tensile tests were detected by a high-spatial-resolution magnetic probe. The domain-wall (DW) motion, grain, and grain boundary were detected using a magneto-optical Kerr (MOKE) image. The time characteristic of DW motion and MBN signals on different locations was varied during elastic deformation. Therefore, a time-response histogram is proposed in this work to show different DW motions inside the grain and around the grain boundary under low tensile stress. In order to separate the variation of magnetic properties affected by the grain and grain boundary under low tensile stress corresponding to MBN excitation, time-division was carried out to extract the root-mean-square (RMS), mean, and peak in the optimized time interval. The time-response histogram of MBN evaluated the silicon steel sheet’s inhomogeneous material properties, and provided a theoretical and experimental reference for ferromagnetic material properties under stress.

scholarly journals Statistical Analysis of the Main Ionospheric Trough Using Swarm in Situ Measurements

2020 ◽  
Vol 125 (3) ◽  
Author(s):  
Ercha Aa ◽  
Shasha Zou ◽  
Philip J. Erickson ◽  
Shun‐Rong Zhang ◽  
Siqing Liu
Keyword(s):  
Statistical Analysis ◽  
In Situ Measurements ◽  
Main Ionospheric Trough

scholarly journals Identifying Spatial and Temporal Variations in Concrete Bridges with Ground Penetrating Radar Attributes

2021 ◽  
Vol 13 (9) ◽  
pp. 1846
Author(s):  
Vivek Kumar ◽  
Isabel M. Morris ◽  
Santiago A. Lopez ◽  
Branko Glisic
Keyword(s):  
Compressive Strength ◽  
Ground Penetrating Radar ◽  
Material Properties ◽  
Temporal Variations ◽  
Concrete Bridges ◽  
Spatial And Temporal Variation ◽  
Reflected Waves ◽  
Ground Penetrating ◽  
Over Time

Estimating variations in material properties over space and time is essential for the purposes of structural health monitoring (SHM), mandated inspection, and insurance of civil infrastructure. Properties such as compressive strength evolve over time and are reflective of the overall condition of the aging infrastructure. Concrete structures pose an additional challenge due to the inherent spatial variability of material properties over large length scales. In recent years, nondestructive approaches such as rebound hammer and ultrasonic velocity have been used to determine the in situ material properties of concrete with a focus on the compressive strength. However, these methods require personnel expertise, careful data collection, and high investment. This paper presents a novel approach using ground penetrating radar (GPR) to estimate the variability of in situ material properties over time and space for assessment of concrete bridges. The results show that attributes (or features) of the GPR data such as raw average amplitudes can be used to identify differences in compressive strength across the deck of a concrete bridge. Attributes such as instantaneous amplitudes and intensity of reflected waves are useful in predicting the material properties such as compressive strength, porosity, and density. For compressive strength, one alternative approach of the Maturity Index (MI) was used to estimate the present values and compare with GPR estimated values. The results show that GPR attributes could be successfully used for identifying spatial and temporal variation of concrete properties. Finally, discussions are presented regarding their suitability and limitations for field applications.

The measurement of groundwater temperature in shallow piezometers and standpipes

2005 ◽  
Vol 42 (5) ◽  
pp. 1377-1390 ◽  
Author(s):  
Matthew D Alexander ◽  
Kerry TB MacQuarrie
Keyword(s):  
Finite Element ◽  
Statistical Analysis ◽  
Transport Model ◽  
Shallow Groundwater ◽  
Subsurface Temperature ◽  
Groundwater Temperature ◽  
Monitoring Well ◽  
Laboratory Results ◽  
The Impact

Accurate measurements of in situ groundwater temperature are important in many groundwater investigations. Temperature is often measured in the subsurface using an access tube in the form of a piezometer or monitoring well. The impact of standpipe materials on the conduction of heat into the subsurface has not previously been examined. This paper reports on the results of a laboratory experiment and a field experiment designed to determine if different standpipe materials or monitoring instrument configurations preferentially conduct heat into the shallow sub surface. Simulations with a numerical model were also conducted for comparison to the laboratory results. Statistical analysis of the laboratory results demonstrates that common standpipe materials, such as steel and polyvinylchloride (PVC), do not affect temperature in the subsurface. Simulations with a finite element flow and heat transport model also confirm that the presence of access tube materials does not affect shallow groundwater temperature measurements. Field results show that different instrument configurations, such as piezometers and water and air filled and sealed well points, do not affect subsurface temperature measurements.Key words: groundwater temperature, temperature measurement, conduction, piezometers, piezometer standpipes, thermal modelling.

Alteration by Cerium Element on Primary and Eutectic Mg2Si Phases in Al-20%Mg2Si In Situ Composite

2015 ◽  
Vol 1125 ◽  
pp. 23-27 ◽  
Author(s):  
Nur Azmah Nordin ◽  
Saeed Farahany ◽  
T. Abubakar ◽  
Esah Hamzah
Keyword(s):  
Material Properties ◽  
Microstructural Analysis ◽  
Eutectic Cell ◽  
Characteristic Parameters ◽  
In Situ Composite ◽  
Melt Treatment ◽  
Morphology Effect ◽  
Polygonal Shape ◽  
Fibre Form

Owing to its beneficial material properties, Al-Mg2Si in-situ composite has recently received wide attention and application in the manufacture of automotive and aerospace components. Melt treatment of the in-situ composite with the addition of Ce has resulted in a change in the primary and eutectic Mg2Si phases to refined morphology, which would be expected to improve the mechanical properties of the composite. Characteristic parameters of Mg2Si particles have been investigated via thermal and microstructural analysis. This has revealed that the addition of 0.8wt.% Ce produced optimum refinement effects on Mg2SiP because the coarse structure has been changed to a polygonal shape and reduced in size. Similarly, the flake-like morphology of Mg2SiE has been transformed into a rod-like or fibre form in addition to reduction of the eutectic cell area. The result also showed an increase in nucleation temperature TN of Mg2SiP while depressed for Mg2SiE, which also corresponds to the refinement morphology effect.

Interplanetary dust observations with the Solar Orbiter RPW instrument: a first year of data.

2021 ◽  
Author(s):  
Arnaud Zaslavsky ◽  
Ingrid Mann ◽  
Stuart Bale ◽  
Andrzej Czechowski ◽  
Karine Issautier ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Interstellar Dust ◽  
Plasma Waves ◽  
Interplanetary Dust ◽  
First Year ◽  
Voltage Waveform ◽  
Dust Density ◽  
Spacecraft Trajectory ◽  
Impact Data

<p>Impacts of dust grains on spacecraft are known to produce typical impulsive signals in the voltage waveform recorded at the terminals of electric antennas. Such signals are, as could be expected, routinely detected by the radio and plasma waves (RPW) instrument aboard Solar Orbiter, therefore providing in-situ measurements of the interplanetary dust density along the spacecraft trajectory.<br><br>We present a statistical analysis of the first year and half of dust impact data recorded by Solar Orbiter RPW between 1 AU and 0.5 AU. We discuss the results in terms of constraints that can be put on beta-meteoroids and interstellar dust fluxes, and compare them to results obtained by STEREO at 1 AU and more recently by Parker Solar Probe at 0.5 AU.</p>

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