Dielectric properties of α-d-glucose aqueous solutions at 2450 MHz
Abstract Using a cavity perturbation technique, dielectric properties of α- d -glucose aqueous solution at 2450 MHz were measured at concentrations ranging from 10 to 60% in the temperature range of 0–70 °C. Dielectric constant increases with temperature in a quadratic manner while linearly decreasing with glucose concentration. Dielectric loss factor decreases with temperature in a quadratic way. The loss factor–concentration relationship depends on the temperature. At lower temperature, loss factor increases linearly with concentration up to a certain concentration then decreases. At temperatures higher than 40 °C, loss factor linearly increases with concentration at all concentration ranges studied. The results are useful for studying volumetric heating of these solutions by microwave energy, and chemical changes such as Maillard reaction and mutarotation involving glucose aqueous solutions in microwave field.
Abstract Polyacrylamide gel electrophoresis in discontinuous buffer systems often gives very narrow zones. This technique involves some disadvantages, however, which are discussed. Although our experience so far is rather limited, it would indicate that the resolving power is independent of whether a continuous or discontinuous buffer system is used, provided that the starting zone is sharpened to the same width in the two systems. A zone sharpening can easily be achieved by giving the sample a lower conductivity than the buffer.