Co-author: Lúıs Castro We will present a study of the Fredholm property for matrix Wiener-Hopf plus/minus Hankel operators with semi-almost periodic Fourier symbols. The Fredholm property will be described based on certain factorizations of the representatives at infinity of the original symbols, and on the geometrical mean values of the corresponding factors. The Fredholm indices of those oper...

A comparison of the performance of molecular descriptors of different types was conducted. The study was concentrated on determining which descriptors are included in the best linear multivariate regression models constructed for modeling various physicochemical properties (melting point, boiling point, refractive index, molar volume, and density) and biological activities (anaesthetic activity...

The study of topological indices - graph invariants that can be used for describing and predicting physicochemical or pharmacological properties of organic compounds - is currently one of the most active research fields in chemical graph theory. In this paper we study the Schultz index and find a relation with the Wiener index of the armchair polyhex nanotubes TUV C(6)[2p; q]. An exact expressi...

Different topological indices will always be valuable in a variety of disciplines, including chemistry, economics, electronics, business studies, social sciences and medicine. According to the dominating set number, Wiener index for neutrosophic graphs (NG) studied considerable detail this research.
 Additionally, Average an NG has been defined, several associated theorems have introduced.

For a nontrivial graph G, its first Zagreb coindex is defined as the sum of degree sum over all non-adjacent vertex pairs in G and the second Zagreb coindex is defined as the sum of degree product over all non-adjacent vertex pairs in G. Till now, established results concerning Zagreb coindices are mainly related to composite graphs and extremal values of some special graphs. The existing liter...

Problems of Nehari type are studied for matrix valued k-variable almost periodic Wiener functions: Find contractive k-variable almost periodic Wiener functions having prespeciied Fourier coeecients with indices in a given halfspace of R k. We characterize the existence of a solution, give a construction of the solution set, and exhibit a particular solution that has a certain maximizing propert...

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...

A biological assessment of the Tang Sorkh River (Iran) was studied from July 2013 to August 2014 using benthic macroinvertebrate communities. Samples were gathered every two months, from five stations using a Surber sampler( 30×30cm), fixed in formalin (4%) and then separated and identified in the laboratory. Environmental conditions (current velocity, temperature, depth, width, dissolve oxygen...