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    Application of the linear principle for the strongly-correlated variables: Calculations of differences between spectra
    (Elsevier Science Bv, 2011) Nigmatullin, R. R.; Popov, I. I.; Baleanu, D.; Dinc, E.; Solak, A. O.; Eksi, H.; Guzel, R.
    In this paper the authors suggest a new method of detection of possible differences between similar near infrared (NIR) spectra based on the self-similar (fractal) property. This property is a general characteristic that belongs to a wide class of the strongly-correlated systems. As an example we take a set of NIR spectra measured for three systems: (1) glassy carbon (GC) electrodes, (2) GC electrodes affected by azobenzene (AB) substance and finally (3) films (AB-FILM). Besides the physical model that should describe the intrinsic properties of these substances we found the fitting function that follow from the linear principle for the strongly-correlated variables. This function expressed in the form of linear combination of 4 power-law functions describes with the high accuracy the integrated curves that were obtained from the averaged values of the initially measured spectra. The nine fitting parameters can be considered as the quantitative finger prints for detection of the differences between similar spectra. Besides this result we established the self-similar behavior of the remnant functions. In other words, the difference between the initially integrated function and its fitting function can be expressed in the form of linear combinations of periodical functions having a set of frequencies following to relationship omega(k) = omega(0)xi(k), where the initial frequency omega(0) and scaling factor xi are determined by the eigen-coordinates method. This behavior in the NIR spectra was discovered in the first time and physical reasons of such behavior merit an additional research. (C) 2011 Published by Elsevier B.V.
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    Removal of cadmium and lead from aqueous solution by calcite
    (Hard, 2007) Yavuz, Oe.; Guzel, R.; Aydin, F.; Tegin, I.; Ziyadanogullari, R.
    The removal of toxic cadmiurn(II) and lead(II) from aqueous solutions was investigated using calcite, which is inexpensive and widespread over the globe, as the effective inorganic adsorbent. The experimental data of the removal equilibrium were correlated by either the Langmuir or Freundlich equations. Results indicate that the Langmuir model gave a better fit to the experimental data than the Freundlich equation. Maximum adsorption capacities were determined as 18.52 mg/g Cd and 19.92 mg/g Pb for natural calcite at 25 degrees C, respectively.