Effects of Heterogeneity in Rock Samples on Spatial and Temporal Distribution of Acoustic Emission and Their Significance for Seismology

2004 ◽  
Vol 47 (1) ◽  
pp. 143-148 ◽  
Author(s):  
Sheng-Li MA ◽  
Xing-Lin LEI ◽  
Li-Qiang LIU
Keyword(s):  
Acoustic Emission ◽  
Temporal Distribution ◽  
Spatial And Temporal Distribution ◽  
Rock Samples

Study of Damage and Acoustic Emission Properties of Rocks under Uniaxial Cyclic Load-Unload

2014 ◽  
Vol 887-888 ◽  
pp. 878-881
Author(s):  
Li Song ◽  
Lin Gu ◽  
Sai Ping Wei
Keyword(s):  
Numerical Simulation ◽  
Acoustic Emission ◽  
Damage Evolution ◽  
Cyclic Load ◽  
Temporal Distribution ◽  
Simulation Software ◽  
Spatial And Temporal Distribution ◽  
Rock Damage ◽  
Load Curve ◽  
Kaiser Effect

In order to study the damage and sptial spatial and temporal distribution of acoustic emission of rocks under uniaxial cyclic load-unload, test of rocks with various kinds of heterogeneity under uniaxial cyclic load-unload disturbance was conducted using numerical simulation software RFPA2D.Figure destruction and acoustic emission - load curve of rocks were obtained from the test.The results show that destroy of the rock was produced from tensile stress concentration area surrounding the hole. as the load increases,crack developmented to the edge of the rock.when homogeneity of rock was low, crack development with irregularity due to defects of rocks. with the increasing homogeneity of rock, damage evolution mode under uniaxial cyclic load-unload disturbance transition from ductile to brittle.damage evolvement process can be responsed by acoustic emission. with the increasing homogeneity of rock. The maximum number of acoustic emission Continuously improve and exhibit unexpected. Kaiser effect of acoustic emission under cyclic loading is significantly This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text. .

scholarly journals Intercepted Photosynthetically Active Radiation (PAR) and Spatial and Temporal Distribution of Transmitted PAR under High-Density and Super High-Density Olive Orchards

Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 351
Author(s):  
Adolfo Rosati ◽  
Damiano Marchionni ◽  
Dario Mantovani ◽  
Luigi Ponti ◽  
Franco Famiani
Keyword(s):  
Spatial Variability ◽  
Photosynthetically Active Radiation ◽  
Temporal Distribution ◽  
High Density ◽  
Radiation Use Efficiency ◽  
Spatial And Temporal Distribution ◽  
Active Radiation ◽  
Use Efficiency ◽  
And Performance ◽  
Radiation Use

We quantified the photosynthetically active radiation (PAR) interception in a high-density (HD) and a super high-density (SHD) or hedgerow olive system, by measuring the PAR transmitted under the canopy along transects at increasing distance from the tree rows. Transmitted PAR was measured every minute, then cumulated over the day and the season. The frequencies of the different PAR levels occurring during the day were calculated. SHD intercepted significantly but slightly less overall PAR than HD (0.57 ± 0.002 vs. 0.62 ± 0.03 of the PAR incident above the canopy) but had a much greater spatial variability of transmitted PAR (0.21 under the tree row, up to 0.59 in the alley center), compared to HD (range: 0.34–0.43). This corresponded to greater variability in the frequencies of daily PAR values, with the more shaded positions receiving greater frequencies of low PAR values. The much lower PAR level under the tree row in SHD, compared to any position in HD, implies greater self-shading in lower-canopy layers, despite similar overall interception. Therefore, knowing overall PAR interception does not allow an understanding of differences in PAR distribution on the ground and within the canopy and their possible effects on canopy radiation use efficiency (RUE) and performance, between different architectural systems.

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