Reprobing the mechanism of negative thermal expansion in siliceous faujasite

Negative Thermal Expansion

Introduction Many materials which we encounter in everyday life expand on heating. This fact of life is easily highlighted with a simple experiment that we are all familiar with and involves a metallic sphere passing through a metal ring. At room temperature, the sphere is of such a size that it can easily pass through the ring, but after the sphere is heated, it will have expanded with the res...

Negative Thermal Expansion in Ba0.5Sr0.5Zn2SiGeO7

Solid solutions with the composition Ba0.5Sr0.5Zn₂Si2-xGexO₇ and BaZn₂Si2-xGexO₇ were prepared with different values of x using a conventional mixed oxide route. Both compounds exhibit very different thermal expansion, which is due to the different crystal structures. Ba0.5Sr0.5Zn₂Si2-xGexO₇ solid solutions exhibit the structure of high-temperature BaZn₂Si₂O₇ and show negative thermal expansion...

Negative thermal expansion in beta-quartz

M.T. Dove ()) Dept. of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK Abstract Computer modelling and theoretical analysis are used to explain the nearly zero and slightly negative coefficients of thermal expansion in b-quartz well above the a-b phase transition temperature. Quartz was selected for study as an archetypal material with a framework structure of sti...

The origin of uniaxial negative thermal expansion in layered perovskites

‏‎suppression of coke formation in thermal cracking by coke inhibitors‎‏

‏‎the main purpose of this research was to:1.develop a coking model for thermal cracking of naphtha.2.study coke inhibition methods using different coke inhibitors.developing a coking model in naphtha cracking reactors requires a suitable model of the thermal cracking reactor based on a reliable kinetic model.to obtain reliable results all these models shall be solved simultaneously.for this pu...