Turbulent drag reduction (DR) induced by monodispersed high molecular weight λ-DNA in a buffer solution under a turbulent flow was investigated using a rotating disk apparatus. The DR efficiency was maintained over time due to the durability of the λ-DNA in a moderate turbulent shear flow, and this behavior was compared to a water-soluble linear flexible long chain polyacrylamide (PAAM). To investigate the mechanical degradation mechanism of λ-DNA, the maximum drag reducing rotation speed (rpm) of the disk was examined by increasing the rotation speed using two different modes to increase the rpm: a continuous and stepwise mode. The mechanical degradation of λ-DNA with a high turbulent flow was analyzed using an electrophoresis method, which indicated a midpoint scission of the long chain molecules. The DR efficiency at different rotation speeds and results of a long-term experiment also supported the half-length degradation of λ-DNA and strong resistance of the helically stranded λ-DNA structure in a turbulent flow compared to its water-soluble flexible counterpart.

Recent studies involving the linguistic analysis of texts has shown the importance of the interrelationships across the various strata of language. A network based collaborative system represents a major step forward in carrying out such cross-stratum analysis. Two vital prerequisites for developing this system include facilities for retrieval of text resources and a mechanism for capturing complex linguistic information. In this paper, a database framework for collaborative retrieval of complex linguistic information is presented. The framework provides a platform for combining both syntactic and semantic processes of parallel multilingual corpora leading to pattern visualization, speech analysis, speech-to-text transcription and statistical analysis.