• Dušanka Lekić University of Banja Luka, Faculty of Natural Sciences, Mladena Stojanovića 2, Banja Luka, Republic of Srpska
  • Sunčica Elezović Hadžić University of Belgrade, Faculty of Physics, Studentski trg 12, Beograd, Serbia
  • Nataša Adžić Department of Theoretical Physics, J. Štefan Institute, Jamova cesta 39, Ljubljana, Slovenia



We studied compact conformations of a ring polymer adsorbed on the non homogeneous (e. g. porous) substrates. Substrates are represented by the generalization of modified rectangular (MR) lattice – a hierarchically constructed family of fractal lattices embedded in 2d space and parameterized with an integer p >1. Analyzing the exact set of recursive relations for arbitrary value of p, we established an asymptotic form of a number of conformations. As a correction to the leading exponential factor we obtained the stretched exponential factor with the exponent s = 1/2 on each member of the fractal family. Although it is believed that the critical exponent s on fractal lattices is determined not only by the fractal dimension of the underlying lattice but also by other lattice parameters, here we found that s had the same value on different fractals with the same fractal dimension (df = 2).


T. Pavlović, D. Milosavljević, D. Mirjanić, Renewable Energy Sources, Academy of Sciences and Arts of the Republic of Srpska, Banja Luka 2013, 1−364.

A. Luque, S. Hegedus, Handbook of Photovoltaic Science and Engineering, Second Edition, 2011, John Wiley & Sons, 1−1166.

T. Pavlović, Z. Pavlović, L. Pantić, Lj. Kostić, Determining optimum tilt angles and orientations of photovoltaic panels in Nis, Serbia, Contemporary Materials, Vol. I−2 (2010) 151−156.

T. Markvart, L. Castafier, Fundamentals of Photovoltaic Modules and Their Applications, 2003, Elsevier Science Ltd., Oxford, UK,

D. Lj. Mirjanić, S. Maksimović, D. Divnić, The study of energy efficiency of monocrystalline silicon modules, Contemporary Materials, Vol. V−2 (2013) 117−124.

E. Skoplaki, J. A. Palyvos, On the temperature dependence of photovoltaic module electrical performance: A review of efficiency/power correlations, Solar Energy, Vol. 83 (2009) 614–624.

G. Xydis, On the energetic capacity factor of a wind e solar power generation system, Journal of Cleaner Production (2012) 1−9.

T. Pavlović, D. Milosavljević, D. Mirjanić, L. Pantić, I. Radonjić, D. Piršl, Assessments and perspectives of PV solar power engineering in the Republic of Srpska (Bosnia and Herzegovina), Renewable and Sustainable Energy Reviews, Vol. 18 (2013) 119–133.

S. Pless, M. Deru, P. Torcellini, S. Hayter, Procedure for Measuring and Reporting the Performance of Photovoltaic Systems in Buildings, 2005, National Renewable Energy Laboratory, Colorado, USA.

H. Haberlin, Photovoltaics: system design and practice, 2012, John Wiley & Sons, UK.