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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Size Exclusion Chromatography of Poly(2-ethyl-2-oxazoline) Homopolymers and Poly(ethylene oxide)-b-Poly(2-ethyl-2-oxazoline) Copolymers

Barnes, Suzanne R. 18 January 2014 (has links)
Size exclusion chromatography is the method of choice for characterizing molecular weights and molecular weight distributions of polymers. An important advancement in SEC is multidetection SEC which includes multi-angle laser light scattering, viscometry, refractive index and UV spectroscopy to analyze block and graft copolymers as well as polymers with oligomeric molecular weights. Oligomeric molecular weights present special challenges since the light scattering and viscosity detectors are more sensitive to higher molecular weights and both detectors have low molecular weight threshold values. The molecular weights and distributions of poly(2-ethyl-2-oxazoline) oligomers and block copolymers as well as poly(2-ethyl-2-oxazoline) were investigated by SEC using multiple detectors. Both a universal calibration method and light scattering were used to determine molecular weights and molecular weight distributions. The solvent was N-methylpyrrolidone that contained 0.05M LiBr used to minimize interactions among the polymers and solvent. SEC was used to establish that the diblock copolymers had heterogeneous compositional distributions. The low molecular weights of the diblock and homopolymer made it necessary to use the universal calibration method with combined refractive index and viscometry detectors to determine absolute molecular weights. / Master of Science
2

Analýza hlavních sacharidů vína / Analysis of main wine saccharides

Horáková, Hana January 2009 (has links)
This diploma thesis deals with determination of carbohydrates in wine. Theoretical part attends to production of wine from grape to treatment and training of wine. It refers saccharides in wine, especially glucose and fructose. The study provides an overview of the available sources concerning the possibilities of determination of carbohydrates in wine by chromatographic methods and Skalar automated chemistry analyser. The study shortly refers simple analytical methods for determination of wine saccharides. The experimental part based on this search deals with analysis of saccharides by high performance liquid chromatography with refractive index detector and UV detector on aminoalkyl column and determination of reducting sugars by Skalar automated chemistry analyser. Finally, the results of these methods were compared.

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