Testing methods resonance techniques

The hydrogen content of fuel oil can also be measured by low-resolution magnetic resonance spectroscopy (ASTM D-3701, ASTM D-4808). The method is claimed to provide a simple and more precise alternative to existing test methods, specifically combustion techniques (ASTM D-5291), for determining the hydrogen content of a variety of petroleum-related materials. 

Laboratory testing methods are presently used on almost an exclusive basis to establish the requisite information for seafloor soils. These testing methods typically include the cyclic triaxial test (ASTM D5311), the cyclic simple shear, and the resonant column (ASTM D4015) techniques. The range of strain levels produced by these test apparatus are... 

Combining separation and analysis techniques (hyphenated techniques) can produce powerful tools for chtiracteriz-ing viscous oils. Thus, liquid chromatography or gas chromatography can be used to separate a sample for subsequent characterization by mass spectrometry (LC/MS or GC/MS). Research into suitable methods for the analysis of viscous oils is underway, but no standard tests have yet been prepared. Extensive research on both proton and carbon-13 nuclear magnetic resonance spectroscopy shows promise as a tool for the analysis of lubricant base oils and other viscous oils. Both near-infrared spectroscopy (NIR) and Fourier-transform IR (FTIR) are the subjects of active research into methods to characterize hydrocarbons and for quality control during production of petroleum products. Standard test methods using these techniques should become available in the future. 

The room temperature in-plane shear, interlaminar shear, and axial Young s moduli of beams cut from plates of two different C/C laminates have been determined by a resonant beam method. The technique and evaluation method are described in detail. The results are discussed and compared to data from static tests. 

On page 25 of the November 2001 issue of Adhaesion, Kleben Dichten, the nuclear magnetic resonance contact technique was introduced as a new sort of method for non-destructive characterisation of polymers. This article uses examples from the area of epoxy resins and thick-layer bondings to give an impression of typical, potential applications for this new non-destructive testing method. 2 refs. 

With this procedure, as with the double-resonance methods in atomic physics, Zeeman and Stark splittings, hyperfine structures and A doublings in molecules can be measured with high precision, even if the observed level splittings are far less than the optical dopp-ler width. From the width of the rf resonance and from the time response of the pumped systems, orientation relaxation rates can be evaluated for individual v J") levels. Other possible applications of this promising technique have been outlined by Zare 30) Experiments to test some of these proposals are currently under investigation and their results will be reported elsewhere. 

---