ELECTROMAGNETIC WAVES
and particulate materials
- J. Carlos Santamarina
Georgia Institute of Technology
Aussois 2012
ELECTROMAGNETIC WAVES and particulate materials J. Carlos - - PowerPoint PPT Presentation
Aussois 2012 ELECTROMAGNETIC WAVES and particulate materials J. Carlos Santamarina Georgia Institute of Technology References: Santamarina, J.C., in collaboration with Klein, K. and Fam, M. (2001). Soils and Waves, J. Wiley and Sons,
Georgia Institute of Technology
Aussois 2012
References: Santamarina, J.C., in collaboration with Klein, K. and Fam, M. (2001). Soils and Waves, J. Wiley and Sons, Chichester, UK, 488 pages. Klein, K. and Santamarina, J. C. (2003b). "Electrical Conductivity In Soils: Underlying Phenomena." Journal of Environmental & Engineering Geophysics, Vol. 8, No. 4, pp. 263-273. Klein, K. and Santamarina, J. C. (1997). "Methods for Broad-Band Dielectric Permittivity Measurements (Soil- Water Mixtures, 5 Hz to 1.3 GHz)." ASTM Geotechnical Testing Journal, Vol. 20, No. 2, pp. 168-178. Santamarina, J. C. and Fam, M. (1997b). "Dielectric Permittivity of Soils Mixed with Organic and Inorganic Fluids (0.02 GHz to 1.30 GHz)." Journal of Environmental & Engineering Geophysics, Vol. 2, No. 1, pp. 37-52. Santamarina, J. C. and Fam, M. (1995). "Changes in Dielectric Permittivity and Shear Wave Velocity During Concentration Diffusion." Canadian Geotechnical Journal, Vol. 32, No. 4, pp. 647-659. Some pdfs (these and related papers) available at http://pmrl.ce.gatech.edu under "Publications"
Mass Bulk stiffness Capillary forces Seepage rate Dipole Hydration and double layers
O2- H+ H+ 109o
30 60 90 120 150 180 210 240 270 300 330
L=1.25r
30 60 90 120 150 180 210 240 270 300 330
L=10r Cl- Cl- Cl- Cl- C4+
Precipitated salt mineral
pore fluid
double layer
Laponite 1200 H2O 24 Na+
free v surf vol
d dv E s E s
free v
1 E
surf
H d s
H
loop surf
d d H d dt E l s
dt dH E
loop surf surf
d d d d dt H l J s E s
dt dE E H
Gauss' Law of Electricity Gauss' Law of Magnetism Faraday's Law of Induction Ampere-Maxwell's Law
Conductivity Permittivity εo ε* = ε’ - j ε” Permeability
Free space Materials
2 2 2
x ( j t x ) y
Consider solution of the form (fluctuates in y - propagates in x) Then
2
in real materials
x ( j t x ) y
if
Faraday then
j t * x z
x y z
ph 2
In free space
ph
m V c 3 10 s
In non-ferromagnetic dielectric
V '
In free space
j "
2
1 1 tan 1 c 2
Frequency [Hz] Wave Wave length [m] 1022 10-14 1021 Gamma rays 10-13 1020 10-12 1019 10-11 1018 X rays 10-10 1017 10-9 1016 Ultraviolet 10-8 1015 10-7 1014 Visible * 10-6 1013 Infrared 10-5 1012 10-4 1011 Microwaves 10-3 1010 10-2 GHz 109 10-1 108 1 107 101 MHz 106 102 105 Radio waves 103 104 104 KHz 103 105 102 106 101 107
free v
1 E
H dt dH E
dt dE E H
Light-surface interaction (Atlanta Airport) and blue butterflies?
van Gogh - La Nuit Etoilee
Fresnel’s Ellipse
Conductivity Permittivity ε* = ε’ - j ε” Permeability = ’ - j ”
Ohmic conduction losses Polarization losses ε”ω Magnetization losses ”ω
" tan '
Non-Ferromagnetic
10 20 30 40 2 4 6 8 10 12 concentration [mol/L] conductivity [S/m]
NaOH NaCl CaCl2
At low concentration (P. Annan):
] L / mg [ TDS 15 . ] m / mS [
fl
el soil
Surface conduction Pore fluid Wet Soil
s g el soil
0.001 0.01 0.1 1 0.4 0.5 0.6 0.7 0.8 0.9 1 porosity, n mixture conductivity,
mix [S/m]
c = 0.1 mol/L c = 10-5 mol/L
Archie s fl soil
fl soil
10-6 10-3 100 10-3 100 Controlled by
eln
Ss clays sands
soil [S/m] el [S/m]
el= soil
de-ionized water fresh water sea water Controlled by (1-n)
gSs
10-6 10-3 100 10-3 100
Controlled by n
el
clays
sands
soil [S/m] el [S/m]
el= soil
de-ionized water fresh water sea water
Controlled by (1-n) 2
g λSs
Ss
Electronic (resonance) t =10
(Ultraviolet) Ionic (resonance) t =10
s
(Infrared) Orientational (relaxation) t = 9 × 10
s
(Microwave – water) Direction of Applied Field
1 10 100 1 103 1 104 1 105 1 106 1 107 1 108 1 109 1 10101 1011 1 10121 10131 1014 1 10151 1016 1 10171 1018 50 50 100 150 200
frequency [Hz] " ' spatial
ionic electronic polarization losses conduction losses 1 102 104 106 108 1010 1012 1014 1016 1018
20 30 40 50 60 70 80 90 1 2 3 4 5 6
'
ionic concentration [mol/L]
CaCl2 NaCl KCl LiCl FeCl3
f = 1.3 GHz
Stern layer (Infrared) Bound water (relaxation) (Radio frequency) Double layer (deionized) Double layer (electrolyte) Double layer - Normal particle interactions (surface conduction) Direction of Applied Field
(no relaxation) Maxwell relaxation Wagner relaxation Direction of Applied Field Semi-permeable membrane
single phase material mixture log(frequency/Hz)
visible range electronic resonance ionic reson. molecular
relax scatter grain bound. micro-space polarization double layer macrospace polarization
(interfacial polarization - relaxation) log(size/m)
water 78 ice ~3 most organic fluids 2-6 air, gasses ~1 minerals 5-10
2 ' ' '
1 1
soil m w
n n S nS
' 2 3
3.03 9.3 146.0 76.7
soil v v v
Topp et al. 1980 CRIM
' ' ' m
1 1
soil w
n n S nS
Linear mixture
water 78.5 methanol 32.6 most organic fluids 2 - 6 quartz 4.2 - 5 calcite 7.7 - 8.5 most minerals 6 – 10
Orientational Pol.
25 30 35 40 0.48 0.5 0.52 0.54 0.56 0.58 0.6 0.62 local volumetric water content 1.3 GHz 0.20 GHz DeLoor ' s (Table 11.9) Volumetric Water Content Permittivity
'
2 v v
7 . 18 6 . 87 40 . 1 '
3 v 2 v v
7 . 76 . 146 3 . 9 03 . 3 '
2 v v
2 v v
. 16 8 . 23 14 . 3 '
2 v v v
1600 392 8 . 44 9 . 3 40 '
2 v
9 . 7 n 6 . 1 6 . 2 '
VOLUMETRIC WATER CONTENT
10 20 30 40 50 60 70 80 90 20 40 60 80 100
volumetric water content [%] real relative permittivity [ ]
Kaolinite Bentonite Mixed clays Sands and silts Topp et al. (1980) Selig and Mansukhani (1975) Wang (1980) Wensink (1993) Based on CRI - S=100%
[Photo: U.S. Environmental Protection Agency]
Magnetically separated fraction: hematite Fe2O3 (weakly magnetic), magnetite Fe3O4 and maghemite Fe2O3 (both strongly magnetic).
Electron orbits
Diamagnetism Electron spin unpaired Paramagnetism Alignment within domains move domain walls Ferromagnetism
domain 1 domain 2 wall
iron fillings in kaolinite – f = 10 kHz
'
rel
volume fraction of iron filings
0.05 0.1 0.15 0.2 0.25 0.3 0.35
1 1.5 2 2.5 3
μ’rel= 1 + 4 vFe+ 7 vFe μ’rel= 1 + 3 vFe Maxwell Wagner
iron in kaolinite – f = 10 kHz
0.1 0.2 0.3 0.4 0.5 102 103 104 105 106 107 Series1 Series2 Series3 Series4 Series5 Series6 Series7
1 1.2 1.4 1.6 1.8 2 2.2
(a) (b) (c) (d) (e) (f) (g) (a) (b) (c) (d) (e) (f) (g) frequency [Hz] frequency [Hz] "
rel
'
rel
102 103 104 105 106 107
Fe
1 3v
2 Fe Fe
1 4v 7v
Single materials water, quartz, kaolinite
(diamagnetic)
~0.9999 montmorillonite, illite, granite, hematite
(paramagnetic)
1.00002-1.0005 nickel, iron
(ferromagnetic)
> 300 Predictive relations spherical ferromagnetic inclusions for vFe<0.2 Kaolinite with iron filings (at 10 kHz) for vFe<0.3
Quasi-DC Wave propagation Standing wave
R, C, L Complex Reflectivity V α
V R i
V j L i V 1 j i C
Resistor (R) Inductor (L) Capacitor (C)
C j R 1 1 i V * Z C 1 L j R i V * Z
SG V1 V2
2 4 6 8 Resistance [k ] Depth [cm]
X-Ray
Varved Clay
Rfix VN VS SG
Photograph X-Ray
2 4 6 8 Resistance [k ] Depth [cm]
2 4 6 8 Resistance [k ] Depth [cm]
Needle probe measurements
1 2 3 16 15 14 13 12 11 10 9 8 7 6 5 4 1 2 3 16 15 14 13 12 11 10 9 8 7 6 5 4
high conductivity anomaly
JY Lee see also Fotti et al.
Coarse aggregate
(honeycomb)
Fresh concrete Fresh concrete Time (10-9 sec)
2 4 6 8 10 12 14 16 18 20 22 24
Reflection at the probe tip
Penetration depth [cm]
5 20 25 30 10 15
Cone in TDR-mode
MS Cha
Syscal Kid Switch 24 Resistivity range: 0.001 to 10,000 Ohm meter Depth less than 70m Typical pulse duration: ~0.5s to 2s.
(images from http://www.terraplus.com)
EM38 Ground Conductivity Instrument Very shallow (~<1m) Conductivity range: 100, 1000mS/m Frequency 14.6kHz Geonics (Mississauga): http://web.idirect.com/~geonics/index.html Images from the Terraplus (Colorado) site: http://www.terraplus.com EM 34 - Ground Conductivity Instrument Shallow (<60 m) Intercoil spacing and operating frequency: 10m at 6.4kHz, 20m at 1.6kHz, 40m at 0.4kHz Conductivity Ranges 10, 100, 1000 mS/m
Sensors and Software (Mississauga) Borehole Antennas (50, 100, 200 MHz) Pulse EKKO 100 antenna frequencies; 12.5, 25, 50, 100, and 200 MHz (also borehole) Pulse EKKO 1000 antenna frequencies; 110, 225, 450, 900, 1200 MHz
(permittivity … conductivity and permeability)
www.sensoft.ca
www.sensoft.ca
www.sensoft.ca
typically non-ferromagnetic caution otherwise (e.g., some mine waste, fly ash) ionic concentration … and mobility fresh water: clay surface conduction Simple measurement: ERT, Needle Probe (invasive) free water orientation (microwave frequency) GPR TDR probe (invasive) V V when
el and
Sd Sd when
el
Use volumetric water content consolidation advect./diffus. fluid fronts salt water intrusion freezing fronts hydrates spatial variability buried anomalies