scholarly journals Linking satellite derived LAI patterns with subsoil heterogeneity using large-scale ground-based electromagnetic induction measurements

Geoderma ◽  
2015 ◽  
Vol 241-242 ◽  
pp. 262-271 ◽  
Author(s):  
S. Rudolph ◽  
J. van der Kruk ◽  
C. von Hebel ◽  
M. Ali ◽  
M. Herbst ◽  
...  
Keyword(s):  
Electromagnetic Induction ◽  
Large Scale

Large‐Scale Mapping of Complex Utility Lines with a Broadband Electromagnetic Induction Array

2006 ◽  
Author(s):  
Scott MacIntosh ◽  
Rasmus Tolboll ◽  
Ralf Birken ◽  
Qifu Zhu
Keyword(s):  
Electromagnetic Induction ◽  
Large Scale

LARGE-SCALE MAPPING OF COMPLEX UTILITY LINES WITH A BROADBAND ELECTROMAGNETIC INDUCTION ARRAY

2006 ◽  
Author(s):  
Scott MacIntosh ◽  
Rasmus Tolboll ◽  
Ralf Birken ◽  
Qifu Zhu
Keyword(s):  
Electromagnetic Induction ◽  
Large Scale

scholarly journals Three-dimensional imaging of subsurface structural patterns using quantitative large-scale multiconfiguration electromagnetic induction data

2014 ◽  
Vol 50 (3) ◽  
pp. 2732-2748 ◽  
Author(s):  
Christian von Hebel ◽  
Sebastian Rudolph ◽  
Achim Mester ◽  
Johan A. Huisman ◽  
Pramod Kumbhar ◽  
...  
Keyword(s):  
Electromagnetic Induction ◽  
Large Scale ◽  
Three Dimensional ◽  
Three Dimensional Imaging ◽  
Structural Patterns

scholarly journals The Janus face of modernity: Michael Faraday in the twentieth century

2008 ◽  
Vol 41 (4) ◽  
pp. 477-516 ◽  
Author(s):  
FRANK A. J. L. JAMES
Keyword(s):  
Twentieth Century ◽  
Gold Standard ◽  
Electromagnetic Induction ◽  
Large Scale ◽  
National Government ◽  
British History ◽  
Great War ◽  
Michael Faraday ◽  
The Great War

AbstractSeptember 1931 is seen by historians as one of the key months in interwar British history. It was the first full month of the National Government, the month of the Invergordon Mutiny and of Britain being forced off the gold standard. It was also the month when large-scale celebrations were held to mark the centenary of the discovery of electromagnetic induction by Michael Faraday. This address discusses the specific events of celebrating Faraday and its consequences; it is framed in relation to, and in some instances directly linked with, the crises of that month and some of the consequences of the Great War, especially the growth of the corporate and coordinated state and the rise of modernity.Let us honour if we canThe Vertical manThough we value noneBut the horizontal one.W. H. Auden, Poems, London, 1930, dedication

An Electromagnetic Energy Harvester of Large-scale Bistable Motion by Application of Stochastic Resonance

2021 ◽  
pp. 1-24
Author(s):  
Wei Zhao ◽  
Rencheng Zheng ◽  
Xiangyan Yin ◽  
Xilu Zhao ◽  
Kimihiko Nakano
Keyword(s):  
Energy Harvesting ◽  
Stochastic Resonance ◽  
Electromagnetic Induction ◽  
Large Scale ◽  
Energy Harvester ◽  
Electromagnetic Energy ◽  
Resonance Phenomenon ◽  
Mutual Position ◽  
Mass System ◽  
Systematic Response

Abstract Vibrational energy harvesting has attracted considerable research attention for electrical power collection from ambient vibrations. Thereby, this study firstly developed an electromagnetic energy harvester of large-scale bistable motion by application of stochastic resonance, to enhance energy harvesting efficiency at a broadly low frequency. The electromagnetic energy harvester is fabricated by a magnet-coil generator and an oblique-supported spring-mass system. In the beginning, a weighting function is originally proposed considering mutual position relationship of the magnet and coil, and a motion equation and an electromagnetic induction equation are simultaneously established considering both elastic spring recovery force and electromagnetic induction Lorentz force. Subsequently, numerical analysis is processed to resolve the simultaneous equations to obtain systematic response displacement and the induced voltage, and the numerical solutions are accurately consistent with the measuring results in validation experiments. Furthermore, a damping coefficient is identified considering the mutual effectiveness of the damping forces from the normal friction and electromagnetic induction, and the influence of electromagnetic induction damping on systematic response displacement is carefully discussed. Eventually, experimental results clarified that the stochastic resonance phenomenon actually occurred as a large-scale bistable motion, and it is further validated that power generation efficiency can be noticeably enhanced following amplitude amplifications of systematic response displacement.

Integrated analysis of multi-scale electrical signatures for characterizing soil water dynamics in century-old biochar enriched agroecosystems

2020 ◽  
Author(s):  
Edmundo Placencia-Gomez ◽  
Victor Burgeon ◽  
Ramin Heidarian-Dehkordi ◽  
Jeroen Meersmans ◽  
Mihai Cimpoiasu ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Soil Moisture ◽  
Soil Water ◽  
Electromagnetic Induction ◽  
Large Scale ◽  
Induced Polarization ◽  
Water Dynamics ◽  
Soil Water Dynamics ◽  
Intermediate Scale ◽  
Multi Scale

<p>Electrical resistivity and induced polarization tomography and electromagnetic induction are widely used in hydrogeophysical applications. In this work we perform a multi-scale analysis of DC-resistivity, spectral induced polarization (SIP) and electromagnetic induction (EMI) measurements to evaluate soil water dynamics of a century-old biochar enriched agroecosystem. Our study aims at comparing the spatio-temporal variations of the electrical signature (resistivity or conductivity) between the natural (reference) soil and soil enriched with biochar visible as black patches ( 0.30 m thick x 20 m of diameter) in the study area and relate this signature to a soil moisture status. In this first overall and qualitative approach we combine 1) field large-scale time-lapse electrical resistivity tomography (ERT) transects (12.6 m) and EMI conductivity maps covering the whole study area (13 ha), 2) intermediate-scale ERT/SIP profiles from on-site pits (2 m L x 1 m W x 1 m D), and 3) laboratory columns-scale (0.10 m L x 0.044 m ID) SIP signatures of undisturbed soil samples.</p><p>Large-scale results show a heterogeneous-resistive soil top horizon in both soil types, but with similar hydrodynamic behaviour following precipitation events. The column scale SIP signatures reveal that texture and pore structure are the main driver of soil moisture dynamics with insignificant role of the biochar content. Large and intermediate scale monitoring campaigns during the entire growing season of two different crops are planned for the current and next year. The ultimate objective is to quantify the effect of century-old biochar on soil water dynamics and root water uptake.</p>

scholarly journals Differentiating tidal and groundwater dynamics from barrier island framework geology: Testing the utility of portable multifrequency electromagnetic induction profilers

Geophysics ◽  
2016 ◽  
Vol 81 (5) ◽  
pp. E347-E361 ◽  
Author(s):  
Bradley A. Weymer ◽  
Mark E. Everett ◽  
Chris Houser ◽  
Phil Wernette ◽  
Patrick Barrineau
Keyword(s):  
Electromagnetic Induction ◽  
Large Scale ◽  
Low Frequency ◽  
Barrier Island ◽  
Step Response ◽  
Small Scale ◽  
Near Surface ◽  
Groundwater Dynamics ◽  
Dry Conditions ◽  
Text Signal

Electromagnetic induction (EMI) techniques are becoming increasingly popular for near-surface coastal geophysical applications. However, few studies have explored the capabilities and limitations of portable multifrequency EMI profilers for mapping large-scale ([Formula: see text]) barrier island hydrogeology. The purpose of this study is to investigate the influence of groundwater dynamics on apparent conductivity [Formula: see text] to separate the effects of hydrology and geology from the [Formula: see text] signal. Shore-normal and alongshore surveys were performed within a highly conductive barrier island/wind-tidal flat system at Padre Island National Seashore, Texas, USA. Assessments of instrument calibration and signal drift suggest that [Formula: see text] measurements are stable, but vary with height and location across the beach. Repeatability tests confirm [Formula: see text] values using different boom orientations collected during the same day are reproducible. Measurements over a 12 h tidal cycle suggest that there is a tide-dependent step response in [Formula: see text], complicating data processing and interpretation. Shore-normal surveys across the barrier/wind-tidal flats show that [Formula: see text] is roughly negatively correlated with topography and these relationships can be used for characterizing different coastal habitats. For all surveys, [Formula: see text] increases with decreasing frequency. Alongshore surveys performed during different seasons and beach states reveal a high degree of variability in [Formula: see text]. Here, it is argued that surveys collected during dry conditions characterize the underlying framework geology, whereas these features are somewhat masked during wet conditions. Differences in EMI signals should be viewed in a relative sense rather than as absolute magnitudes. Small-scale heterogeneities are related to changing hydrology, whereas low-frequency signals at the broadest scales reveal variations in framework geology. Multiple surveys should be done at different times of the year and tidal states before geologic interpretations can confidently be made from EMI surveys in coastal environments. This strategy enables the geophysicist to separate the effects of hydrology and geology from the [Formula: see text] signal.

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