Recently, we have reported on calculation of π-electron ring currents in several smaller fully benzenoid hydrocarbons having up to eight fused benzene rings and five Clar π-aromatic sextets. In contrast to early HMO ring current calculations and more recent ab initio calculations of π-electron density, our current calculations are based on a graph theoretical model in which contributions to ring currents comes from currents associated with individual conjugated circuits. In this contribution, we consider several larger fully benzenoid hydrocarbons having from 9 to 13 fused rings and from six or seven π-aromatic sextets. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011

Bosnia and Herzegovina is distinguished by a very unique mosaic of high biodiversity level. However, current development activities and initiatives for construction of new dams, together with activities in the forestry sector throughout the country, emphasizes the need for establishment of new protected areas in all major ecosystem types that should be ecologically viable and effectively managed. A review of the history of protected areas and administration developments in Bosnia and Herzegovina provide useful input for analysis. However, the data on the current state and size of protected areas in the country are obsolate and inaccurate. The results of the analysis have shown that in spite of a very high biodiversity level, Bosnia and Herzegovina managed to designate only 2.6% of its territory as protected areas, which is far below regional and European level. Lack of protected areas system is one of the main direct threats to biodiversity conservation. The primary objective of establishment of protected area network (PAN) in Bosnia and Herzegovina is to ensure conservation of valuable natural areas, which contain representatives of all main ecosystem types that could be found in the country. Only in this way, sustainable conservation of biodiversity could be achieved.

This paper deals with the FEM simulations of anisotropic flow during bulk forming (forging) of magnesium AZ80 wrought alloy at warm conditions. Anisotropic characteristics are described by the classical formulation of Hill’s (1948) quadratic anisotropic yield law. To define reliable FEM models capable of carrying out numerical simulations of complex bulk forming operations in a reasonable amount of computing time, a simplified approach for determining Hill’s anisotropic coefficients as constants is proposed. On the basis of the determined Hill’s anisotropic coefficients and the mechanical properties, the results of an extensive FEM study of lab-scale and industrial-scale forging are shown. FEM results are also compared to the actual obtained results. It is shown that the approach presented can be successfully used in industrial practice. DOI: http://dx.doi.org/10.5755/j01.mech.18.3.1876