Electron spin resonance studies instrumentation technique

This volume covers a wide range of fundamental topics in coal maceral science that varies from the biological origin of macerals to their chemical reactivity. Several chapters report novel applications of instrumental techniques for maceral characterization. These new approaches include solid l3C NMR, electron spin resonance, IR spectroscopy, fluorescence microscopy, and mass spectrometry. A recently developed method for maceral separation is also presented many of the new instrumental approaches have been applied to macerals separated by this new method. The contributions in this volume present a sampling of the new directions being taken in the study of coal macerals to further our knowledge of coal petrology and coal chemistry. 

Electron spin resonance (ESR) spectroscopy a technique used for the study of substances that are paramagnetic, a property caused by the presence of unpaired electrons. In biological materials paramagnetism is principally found in two main types of molecular species, free radicals and those that contain a transition metal ion. Some spectroscopists confine the term ESR spectroscopy to the study of free radicals, because they have an identifiable electron spin, and use the term electron paramagnetic resonance (EPR) spectroscopy for the study of transition metals, where paramagnetism arises from the distribution of electrons in the d orbitals. However the spectra are taken with the same instrumentation and most authors use the terms ESR- and EPR spectroscopy either interchangeably or according to personal preference. 

Many approaches have been used to study membrane structure electron microscopy of freeze-fractured and freeze-etched preparations, localization of antigens using ferritin-labelled antibodies, crossed immunoelectrophoresis, chemical probes and cross-linking agents, and instrumental techniques such as nuclear magnetic resonance and electron spin resonance spectroscopy. Their contribution to our present understanding of membrane anatomy has been reviewed by Salton and Owen [24]. 

Various instrumental methods applied or developed at MMI over the past ten years to study liquid state transitions are presented. T>Tg transition studies with an emf asis on polystyrene are discussed. Instrumental techniques cover the areas of dielectric relaxation, thermal methods, dynamic mechanical relaxation, and computer statistical analysis of tabulated literature data, as well as the spectroscopic methods of Fourier transform infrared and electron spin resonance. 

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