LEVEL: INTERMEDIATE T echniques of both analytical and preparative liquid chromatography have advanced substantially in recent years. Nowadays, samples are often analyzed or purified in systems that incorporate one or more f low-stream changes from one mobile phase to another. It happens, for example, in column switching, in multidimensional separations, and in simulated moving bed (SMB) chroma...

This paper presents an approach to classifying amorphous polymer materials. Temperature is classification involves the determination of mechanical and viscoelastic characteristics considered a descriptive variable clarify specific field practical applications polymers. according reference temperature characterizing behaviour The polymers such as methyl poly-methacr...

introduction corn has been recently used for producing ethanol fuel in the major corn-producing countries such as the us and brazil. recent diversion of corn for biofuel production along with the increased world's demand for this feedstuff has resulted in unprecedented rise in feed cost for poultry worldwide. alternative grains such as wheat and barley can be successfully replaced for corn in p...

The “glass transition problem,” which refers to the spectacular change in dynamic properties of liquids cooled towards their glass transition, remains unsolved. The difficulty is that there are many properties associated with vitrification of a liquid, and these have interrelationships which complicate any analysis. Recently attention has been directed at the spatial heterogeneity of the dynami...

The interest in techniques for enhanced oil recovery has grown due to the need to improve oil productivity reducing water injection and production. Although waterflooding is the most widely used method to recover oil, this process becomes less effective when the mobility ratio is unfavorable and the displacement efficiency is low. Furthermore, great volumes of injected and produced water lead t...

– We investigate the static shear viscosity on the sol side of the vulcanization transition within a minimal mesoscopic model for the Rouse-dynamics of a randomly crosslinked melt of phantom polymers. We derive an exact relation between the viscosity and the resistances measured in a corresponding random resistor network. This enables us to calculate the viscosity exactly for an ensemble of cro...

Dendritic polymers are highly branched polymers with controllable structures, which possess a large population of terminal functional groups, low solution or melt viscosity, and good solubility. Their size, degree of branching and functionality can be adjusted and controlled through the synthetic procedures. These tunable structures correspond to application-related properties, such as biodegra...