we derived explicit formulae for the eccentric connectivity index and wiener index of2-dimensional square-octagonal tuc4c8(r) lattices with open and closed ends. newcompression factors for both indices are also computed in the limit n-->∞.

Chemical structures are mathematically modeled using chemical graphs. The graph invariants including algebraic polynomials and topological indices related to the structure of molecules. Hosoya polynomial is a distance based closed form several indices. This article devoted compute two different atomic configurations (C4C8(R) C4C8(S)) C4C8 Carbon Nanosheets. nanosheets most stable, flexible unif...

Rattans (subfamily Calamoideae) are an important component of the forests of the Old World. However, few studies have been conducted on the distribution of these abundant palms within different habitats, specifically in Peninsular Malaysia. This study was aimed at assessing rattan diversity, abundance and biomass change across two different habitat types, namely, dipterocarp forests and fresh-w...

In the drug design process, one wants to construct chemical compounds with certain properties. In order to establish the mathematical basis for the connections between molecular structures and physicochemical properties of chemical compounds, some so-called structure-descriptors or ”topological indices” have been put forward. Among them, the Wiener index is one of the most important. A long sta...

Forests are biologically diverse systems, representing some of the richest biological areas on Earth. They offer a variety of habitats for plants, animals and micro-organisms. However, forest biodiversity is increasingly threatened as a result of deforestation, fragmentation, climate change and other stressors. Biodiversity is the variation of life forms within a given ecosystem, biome, or on t...

In theoretical chemistry, distance-based molecular structure descriptors are used for modeling physical, pharmacologic, biological and other properties of chemical compounds. We introduce a generalizedWiener polarity indexWk(G) as the number of unordered pairs of vertices {u, v} of G such that the shortest distance d(u, v) between u and v is k. For k = 3, we get standard Wiener polarity index. ...