The development of a new highly sensitive electron paramagnetic resonance probe suitable for measuring low oxygen concentrations in biological cells and tissues is reported. This probe consists of a char prepared from glucose. This char exhibits an EPR spectrum with marked oxygen-dependent linewidth
Development of a Heterodyne Photon Correlation Spectroscopy Measuring Probe for Highly Concentrated Dispersions
β Scribed by Alexander W. Willemse; Henk G. Merkus; Brian Scarlett
- Publisher
- Elsevier Science
- Year
- 1998
- Tongue
- English
- Weight
- 137 KB
- Volume
- 204
- Category
- Article
- ISSN
- 0021-9797
No coin nor oath required. For personal study only.
β¦ Synopsis
A new FOQELS setup is described for use in concentrated dispersions. A fiber-to-fiber coupler is introduced as an extra local oscillator source. This results in a reliable determination of the diffusion coefficient of concentrated dispersions where the heterodyne mode appertains at every concentration. This system is compared with others and results are presented of measurements of a 176-nm latex dispersion and a 230-nm titanium-dioxide dispersion. The diffusion coefficients measured with the new setup clearly differ from those measured with a single optical fiber probe, which are within the mixed homodyne-heterodyne regime; when taking this degree of mixing into account, the latter results can be transferred to the value of the true diffusion coefficients. For prolonged and robust measurement of highly concentrated dispersion, however, direct measurements with heterodyne probes arepreferred. Copyright 1998 Academic Press.
π SIMILAR VOLUMES
The suitability of photon correlation spectroscopy (PCS) for the determination of concentration and size distribution of colloidal matter was tested in a surface water and.in a deep groundwater. Well-defined colloids (sizes predominately in the range 50-500 nm) of a-FezO,, y-AI(O SiOz, kaolinite, il