the thermal degradation of polyethylene (pe) was carried out in the absence and presence ofcatalystes x-zeolite and silica-alumina at different temperatures. the optimum pe/catalysisratio was 0.25:0.05 g/g, which produced highest degradation value. pe and pe/catalysis werecharacterized by thermogravimetric analysis. the thermal degradation properties of polymerhave been studied by infrared spec...

We report a new local exchange-correlation energy functional that has significantly improved across-the-board performance, including main-group and transition metal chemistry and solid-state physics, especially atomization energies, ionization potentials, barrier heights, noncovalent interactions, isomerization energies of large moleucles, and solid-state lattice constants and cohesive energies.

Symmetry and pairing energies of atomic nuclei are related to the differences between the excitation energies of isobaric analog states in the same nucleus. Numerous such excitation energies are known experimentally. In addition, a comprehensive global set can be deduced from the available experimental masses by applying Coulomb energy corrections. Replacing the experimental mass data by availa...

The remarkable development of sciences and technologies in the world of]o today has apparently brought mankind comfort and well-being, but it has also created new problems for humans including environmental pollution, widespread changes in world weather conditions, etc. Fossil fuels cause numerous environmental pollutions. In other words, on the one hand poisonous gases enter the environment fo...

Let graph energy is a graph--spectrum--based quantity‎, ‎introduced in the 1970s‎. ‎After a latent period of 20--30 years‎, ‎it became a popular topic of research both‎ ‎in mathematical chemistry and in ``pure'' spectral graph theory‎, ‎resulting in‎ ‎over 600 published papers‎. ‎Eventually‎, ‎scores of different graph energies have‎ ‎been conceived‎. ‎In this article we...