ISSN: 2277-3754 ISO 9001:2008 Certified International Journal of Engineering and Innovative Technology (IJEIT) Volume 2, Issue 7, January 2013 Measurement of Dielectric Properties of various Stones of Mewar Region of at X-band Microwave Frequencies Bapna P.C, Joshi S

porosity and mineralogy [2]-[12]. Dielectric dispersion at low Abstract— The natural reservoirs of Marble stones in the frequency are useful to understand the behavior of induced Mewar region of Rajasthan, has tremendous commercial polarization in the material while high frequency importance. These decorative stones prevail in wide variety of measurements are helpful in planning ground penetrating colours and textures. The present paper envisages the dielectric characteristics of such stones at X-band microwave frequencies. A radar surveys and microwave remote sensing of the Earth's measurement setup at X-band is described for the experimental geology of the minerals and rocks[9],[10]. The relative determination of relative dielectric constant of various marble permittivity is directly related to the electronic, atomic and stones. The regular pattern of the relative dielectric constant orientational polarization of the material. The first two of varying with microwave frequency is revealed. The Relative these are induced by the applied field, and are caused by dielectric constant and its correlation with the type; structure and displacement of the electrons within the atom, and atoms chemical composition of marble are described in the frequency within the molecule, respectively. The third only exists in range of 8.8 – 12.2 GHz. The real part of the relative dielectric polar materials, i.e. those with molecules having a permanent constant among the different type of marble change in the range of 9.5-1. The chemical composition gives somewhat complex dipole moment. Electronic and atomic polarization are relation as the impurities are different in varied colour . temperature independent, but orientational polarization, The imaginary parts of relative dielectric constant shows that loss depending on the extent to which the applied field can order tangent decreases with increase in frequency in the range of the permanent dipoles against the disordering effect of the 0.00027 – 0.0688. The loss tangents are different for various types thermal energy of their environment, varies inversely with of marbles due to variation in the chemical composition. Further, absolute temperature[13]. In view of the growing importance the relative dielectric constants (both real and imaginary) are of laboratory measurements of electrical properties and also determined and reported for wet marbles in the paper. The measurement data may be of vital importance for microwave keeping in view the scarcity of such data on Indian rocks, we remote sensing applications. have carried out measurement of dielectric constant and loss tangent of some Marbles in the Microwave frequency range Index Terms— Dielectric Constant, Dielectric Loss Tangent, from 8.8 GHz to 12.2GHz using two point method of Marble, X-Band Frequency. rectangular waveguide. In the present paper, we have reported the measurement results of relative dielectric constant and I. INTRODUCTION loss tangent of four samples of marbles, Green marble of Microwave remote sensing techniques are now a day’s Keshriya ji (Sample G1), Pink marble of Babarmal (Sample widely adopted and used to estimate the presence of natural P1), White marble of medium to coarse grain of Rajnagar resources beneath the ground surface. The determination of (Sample W1) and White colour with black spots of fine grain electrical property of minerals and rocks plays a vital role in (Sample W2). Further we have studied the influence of developing electrical and e.m. modeling of the earth’s moisture content of the samples on these properties. forming minerals and rocks [1]. Considerable efforts have Petrographic study of the samples has also been made and it been made to study the effect of variation in bulk density, has been attempted to correlate the observed features with mineralogical composition and crystalline structure of rocks variations of the dielectric properties of measured samples. and minerals, their dielectric measurements over wide range of frequency. Dielectric properties of rocks and sediments are II. EXPERIMENTAL DETAILS primarily a function of mineralogy, frequency, water A. Materials saturation, porosity, texture, component geometry and Marble samples of different colours and varieties were electrochemical interactions between rock components, it is obtained from the marble mines of Mewar region of Rajasthan primarily controlled by water saturation and secondarily by (India). White marbles from Rajsamand (W1, W2), Pink Table 1: Physical Characteristics [11] Stratigraphic Megascopic ample Place of Position with Characters/ Trade Place of occurrence Petrographic Characters no. occurrence alpha numeric name etc. map numbers

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ISSN: 2277-3754 ISO 9001:2008 Certified International Journal of Engineering and Innovative Technology (IJEIT) Volume 2, Issue 7, January 2013 G1 Rikhabdeo Rikhabdeo Green Serpentine Rikhabdeo (Keshriya ji) Massive fine grained rock with criss (Keshriya ji) ultra mafic marble Udaipur District crosses mesh of antigorite, specks of Udaipur suite iron ore and irregular grains of District Σ pt1r dolomite.

P1 Babarmal Aravali Pink Marble Babarmal -Devimata Fine to medium grained rock showing -Devimata Supergroup Udaipur District alternate chlorite, quartz, and Udaipur Pt12ab felspar flaky mineral is muscovite District banded nature and flatening of grains banding is defined by quartz felspathic layers and carbonates. W1 Rajnagar-Ag Aravali W1: White with Rajnagar-Agaria Fine, Medium & coarse grained, aria Supergroup bands, and spider Kelwa inequigranular, granoblastic Kelwa W1: pt12ak web of honey Rajsamand District development of flaky minerals in the Rajsamand W2: pt12dg yellow and green interstices between two carbonate W2 District colour. grains, iron dust over carbonate grains. W2: White Kelwa – W1 : Fine Grained white with slight Blebs of smoky light greenish touch. quartz in white W2 : Medium to coarse grained white background. with black spots.

Table 2: Chemical and Geotechnical Properties [11]

Sample no. Chemical Composition Geotechnical Properties

CaO MgO SiO2 Fe2O3 LOI S.G. W.A. U.C.S.

Green (G1)

18.56 21.29 31.51 5.33 21.82 2.75 0.19 1279

Pink (P1)

20.79 2.21 14.35 0.28 24 2.74 0.07 548

White (W1) White (W2) 33 25 0.01 0.12 36 2.85 0.16 642 30 16 0.06 0.95 44 2.87 0.8 1118

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ISSN: 2277-3754 ISO 9001:2008 Certified International Journal of Engineering and Innovative Technology (IJEIT) Volume 2, Issue 7, January 2013

Table 3: Comparison of Real Part of Relative Dielectric Green 6.59206 at 2.7611 at Constant (ϵ') For Dry Marbles (G1) 9.2GHz 4.74840 9.2GHz 12.2GHz Highest Lowest Average Types Resonance Relative Relative Relative Dielectri 2.742404 9.6 of Dielectric Dielectric Frequencie Pink 6.53969266 constant constant c Marble s (P1) at &11.4GH 4.335845 (ϵ') (ϵ') constant at 9.6GHz (ϵ') 11.4Ghz z 3.08872 9.4,10.6,11. 3.079047 Green 7.53698 White 6.957575 at 9.2,11.8G (G1) at 11.0 6 & 5.06878 at 5.183693 at 9.4 GHz (W1) 9.4GHz Hz GHz 12.0 GHz 12.0GHz

3.771358 Pink 9.673022 2.569849 8.8,9.8,10.6 White 9.260075 at (P1) 4.74840 at 8.8 GHz at 10.0GHz & 11.8 GHz (W2) at No peaks 5.362712 8.8GHz 12.2GHz 9.6, 10.2, White 6.855717 1.244868 Table 6: Imaginary Part of Relative Dielectric Loss Tangent (W1) 11.2&11.8 4.183437 (Tanδ) For Wet Marbles at 9.6 GHz at 9.0 GHz GHz Lowest Average Types Highest Resonance White 7.464399 3.06345 at 9.4, 10.4 & Loss Loss loss of Frequencie (W2) 5.099932 tangent at 9.4GHz 12.0GHz 11.0GHz tangent tangent Marble (tanδ) s (tanδ) (tanδ) Table 4: Imaginary Part of Relative Dielectric Loss Tangent (Tanδ) For Dry Marbles Lowest Average 0.00043198 Types Highest Green 0.04273329 9.0 Loss Loss Resonance loss (G1) 2 at 0.008630 of at9.0GHz &10.8GHz tangent tangent Frequencies tangent 11.0GHz Marble (tan δ) (tan δ) (tan δ) 0.00041805 Pink 0.00836 at 9.8 & 11.0 9.2,9.8,10.6, (P1) 9 at 0.006847 Green 0.0687796 0.0006495 9.8GHz GHZ (G1) 11.0,11.8 & 0.01880 10.0GHz at 10.4GHz at 9.2GHz 12.0GHz White 0.01279181 0.00079224 9.4 & 11.4 0.0002012 9.4,10.0,10. (W1) 0.005868 Pink 0.0236978 0.00684 at 9.6GHz at 11.6 GHz GHz (P1) 61 at 8,11.2, & at 10.0GHz 7 9.0GHz 12.0GHz 0.00011905 White 0.015863 at 11.0 & 0.006185 0.0144607 0.0006356 8.8,9.2,10.8, (W2) 5 at 12.2 White 0.00567 8.8 GHz 12.0GHz 19

(W1) 3 at 67 at 11.2 GHz 0 8.8GHz 11.4GHz &12.2GHz 0.0160519 0.0007229 8.8,9.8,10.6, White 0.00624 (W2) 8 at 7 at 11.4 & 3 11.4GHz 9.0GHz 12.0GHz Table 5: Real Part of Relative Dielectric Constant (ϵ') For Wet Marbles

Highest Lowest Resonanc Average Types Relative Relative e Relative of Dielectric Dielectric constant constant Frequenci Dielectric Marble (ϵ') (ϵ') ' es constant (ϵ) Fig1 :( A) Measured Dielectric Constant of Dry Green Marble

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ISSN: 2277-3754 ISO 9001:2008 Certified International Journal of Engineering and Innovative Technology (IJEIT) Volume 2, Issue 7, January 2013

Fig 1 :( B) Measured Loss Tangent of Dry Green Marble Fig 3 (B): Measured Loss Tangent of Dry Pink Marble

Fig 4 (A): Measured Dielectric Constant of Wet Pink Marble

Fig 2 (A): Measured Dielectric Constant of Wet Green Marble

Fig 4 (B): Measured Loss Tangent of Wet Pink Marble

Fig 2 (B): Measured Loss Tangent of Wet Green Marble

Fig 5 (A): Measured Dielectric Constant of Dry Pure White Marble.

Fig 3 (A): Measured Dielectric Constant of Dry Pink Marble Fig 5 (B): Measured Loss Tangent of Dry Pure White Marble

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ISSN: 2277-3754 ISO 9001:2008 Certified International Journal of Engineering and Innovative Technology (IJEIT) Volume 2, Issue 7, January 2013

Fig 6 (A): Measured Dielectric Constant of Wet Pure White Marble Fig 8 (A): Measured Dielectric Constant of Wet Spotted White Marble

Fig 6 (B): Measured Loss of Wet Pure White Marble

Fig 8 (B): Measured Loss Tangent of Wet Spotted White Marble Marbles from Babarmal, Udaipur(P1) and Green Marbles from Keshriya ji, Udaipur(G1). Physical, Chemical & Geotechnical Properties are shown in Table 1 & 2 [11]. Marble blocks were cut by a diamond wheel cutter and sample of marbles were prepared to the size of dielectric cell 68x23x10mm. Surface of sample were made smooth and were Fig 7 (A): Measured Dielectric Constant of Dry Spotted White inserted in dielectric cell. The values of real part of relative Marble dielectric constant (ϵ') and imaginary part of relative dielectric constant (ϵ'') at x-band frequencies were determined by employing the short circuited two point method for rectangular wave guide operating at TE10 mode at room temperature. We have also measured the values of ϵ' and ϵ'' after dipping these samples in water for few days so that they absorb the water completely.

III. RESULTS AND DISCUSSION The chemical compositions and Geotechnical property of all the marble samples are shown in table 2.0. The presence of iron, alumina, and silica may result in the formation of hematite and magnetite. The minerals that result from impurities give marble a wide variety of colours. The purest

Fig 7 (B): Measured Loss Tangent of Dry Spotted White Marble calcite marble is white in colour. Marble containing hematite’s are reddish or pink in colour. Marble that has

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ISSN: 2277-3754 ISO 9001:2008 Certified International Journal of Engineering and Innovative Technology (IJEIT) Volume 2, Issue 7, January 2013 serpentine is green in color. In sample G1 (Green) has higher molecule in the space of inter molecule of dry samples and value of iron, magnesium and silica and lowest calcite in absorbs all the resonance frequencies almost. Similarly the compare to other samples of different colour along with plots of tanδ Vs frequencies are all shows that there are no serpentine. The specific gravity is about 2.75. The fig.1 (a) peaks and dips for the wet samples shown in fig {2(b), 4(b), shows that the values of ϵ' decreases as frequency increases. 6(b) &8(b)} We get highest value 7.53698 at 9.4GHz and lowest 3.088 at 11.0GHz. The average value is 5.0687 though out X-band. IV. CONCLUSION We observe from the plot that there are four peaks at 9.4, The dielectric constants of various marble types are 10.8, 11.6 & 12.0 GHz and dips at 10.4, 11.0, 11.8GHz i.e., measured at x-band frequencies. The dry marbles have shown plot indicates the different resonance frequencies. The Pink wide variation in dielectric constant for different types. The marble sample (P1) has moderate calcite but lowest chemical composition of the marble is probably the key factor magnesium and iron oxides along with some hematite’s as in influencing the dielectric constant of dry marbles. The impurities. The fig.3 (a) shows the highest value of ϵ' is regular decrease in relative dielectric constant with peaks and 9.673022 at 8.8GHz and lowest 2.5698 at 10 GHz, the dips with increase in x-band, these peaks and dips are average value is 4.71508. The peaks are at 8.8, 9.8, 10.2, 10.8 suppressed and shows smooth decline of dielectric constant & 11.8GHz and dips are at 9.3, 10, 11.0 & 12.0GHz. The with increase in frequency. However, the wet marbles Specific gravity is 2.74 The samples of white marbles W1 and saturated with water have shown almost identical values of W2 have highest and lowest silica as impurities. Fig.5 dielectric constant at different x-band frequencies. The (a) W1, shows the variation of ϵ' with frequencies. The typical x- band average dielectric constant of marbles ranges maximum value of ϵ' is 6.8557 at 9.8GHz and minimum of from 4-6 under dry conditions, whereas this range is 4.1 to 4.8 1.244866 at9.0GHz with average value of 4.1834. The peaks for wet marbles. The typical resonance frequencies are 9.4, are at 9.0, 10.0, 10.8 and 11.6GHz with dips at 9.6, 10.2, 11.1 10.6 & 11.8 GHz for different marbles. and 11.8GHz. Fig 6(a)-W2 sample has maximum value 7.4644 at 9.4GHz, Minimum value of 3.063 at 12.0GHz. The REFERENCES average value is 5.0999 with peaks at 9.4, 10.4 and 11.0 and [1] Keller and Frischknecht, " Electrical methods in Geophysical dips at 10.2, 10.8 and 12.0 GHz. Table 3 shows comparison of prospecting." vol.10, Pergamon Press,1966. ' Relative dielectric constant (ϵ) & table 4 shows dielectric loss [2] Alvarez, R.," Complex dielectric permittivity in rocks: A tangent (tanδ) for dry marbles. Whereas table 5 shows method for its measurement and analysis.", Geophysics, 38, comparison dielectric Constant (ϵ' ) & table 6 shows dielectric 920-940, 1973. loss tangent (tanδ) for Wet marbles The calculated values of [3] Ramesh P. Singh, Mahendra P. Singh &- Tarksewar Lal," ' permittivity (ϵ) of dry marbles specimens are plotted against Laboratory measurement of dielectric constant and loss tangent frequency in Figure 1(a),3(a),5(a),7(a) for different colour of Indian rock samples" marbles. These plots show that permittivity of all marbles (http://www.annalsofgeophysics.eu/vol.33 No. (1980). ' decreases with increase in frequency. These decrease in ϵ [4] R.J.Sengwa and A. soni," Dielectric dispersion and microwave believed to be due to polarization associated with charge dielectric study of marble in support of radar investigations." build up at grain boundaries or at grain imperfections of the Indian Journal of pure & applied Physics, vol.43, p 777-782. sample particles of various dielectric properties. Further, the Oct; 2005. contribution of grain size is also an important factor in [5] R.J.Sengwa and A. soni," Dielectric properties of some controlling values of ϵ'[6]-[9]. The samples G1, P1 and W1 minerals of Western Rajasthan.", Indian Journal of Radio & are fine grain marbles but sample W2 is coarse grain white Space physics, vol.37, p 57-63 Feb; 2008. spotted (black) marble. In all samples plot of dry marbles we [6] Q.J.Tain, P.Gang et al, “Reflectance, dielectric constant and observe that number of peaks and drops in values of ϵ' and chemical content of selected sedimentary rocks." International tanδ ( loss tangent) as frequency varies. ϵ′ and ϵ″ cannot vary Journal of remote sensing, 2002, vol. 23, no.23 p5123-5128 independently with frequency, since their frequency (Talyor & Francis). variations are connected through the Kramers–Krönig [7] A. Kumar and S. Sharma, "Measurement of dielectric constant relationship: a drop in ϵ′ with increasing frequency is and loss factor of the dielectric material at microwave necessarily associated with a peak in ϵ″.[14,15]. Loss Tangent frequencies." progress in electromagnetic Research, PIER 69, (tanδ = ϵ'/ϵ") values of these samples are plotted against 47-54, and 2007. frequency in figure {1(b), 3(b),5(b) &7(b)} shows the [8] Magdy F. Iskander and Joel B. DuBow, "Time- and variations similar to the plots of ϵ' accepts the inversion of the frequency-domain techniques for measuring the dielectric peaks and drops i.e., when permittivity increases the loss properties of rocks: A review, Journal of microwave power, 18(1), 1983. tangent has a drop almost at that peak frequency Fig. {2(a), 4(a), 6(a) & 8(a)} shows the variations of dielectric constant [9] Pabitra N. Sen and W.C. Chew, “The frequency dependent with frequencies for wet marbles, they shows that the peaks dielectric and conductivity response of sedimentary rocks." Journal of microwave power, 18(1), 1983. and dips ,which were appearing in the dry conditions are absent in these plots this may be due to the filling of water

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ISSN: 2277-3754 ISO 9001:2008 Certified International Journal of Engineering and Innovative Technology (IJEIT) Volume 2, Issue 7, January 2013 [10] Xiangyun Wang Huadong Guo et al, “Relative dielectric constant from dry rocks", Chinese Science bulletin, vol. 44, issue 24, Dec; 1999, pp 2286-2293. [11] Rosmary Knight and Anthony Endres, " A new concept in modelling the dielectric response of sand stones: defining a wetted rock and bulk water system." Geophysics, vol. 55 no.5 (May1990) p 586-594. [12] Alex Martinez and Alan P. Byrnes, " Modelling Dielectric constant values of geological material: An aid to ground-penetrating Radar data collection and interpretation." Current research in Earth Sciences bulletin 247,part 1. [13] R.N. Clarke, “Dielectric property of Material." NPL, book chapter2.6.5.(htpp://www.kayelaby.npl.co.uk/general_physics /2_6/2_6_5html) [14] Marble resources’ of Rajasthan, An overview in the light of district resources maps by Geological Survey of India.-Dr. R.S.Goyal, J.V. Natani & Dr. K.D. Chowdhary. [15] Natani J.V.," Geoenvironmental impact assessment studies of Marble mining area, Nagaur district, Rajasthan." Rec. Geol. Surv. Ind. Vol. 133 Pt.7, pp. 64-65(2000). [16] Natani J.V., Geoenvironmental impact assessment studies of Makrana Marble. AUTHOR’S PROFILE

Bapna,P.C is Associate Professor at the Department of Electronics & Communication, College of Engineering and Technology, Udaipur. He did B.E. and MBA. He is pursuing Ph.D in Faculty of Engineering from SGV University, Jaipur,. His main research areas are microwave remote sensing, Wireless communication. He has 32 Yrs of experience in engineering field.

Dr. Sunil Joshi is Professor & Head at the Department of Electronics & Communication, College of Engineering and Technology, Udaipur. He did B.E. and ME from MBM Jodhpur. He has awarded Ph.D in Faculty of Engineering from MNIT Jaipur,. His main research areas are millimeter waves, microwave remote sensing Wireless Broadband Channel Modeling, OFC, MIMO Systems .He has 21 Yrs of experience in engineering field

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