Measurement of Viscosity in Liquids Using Reflection Coefficient: Phase Difference Method

Measurement of viscosity of fluids is a critical parameter in determining the state of the fluid (ie. edible products), and the state of the forming solid (ie. molten metals and glasses). Experiments to measure viscosity using ultrasound, have been carried out since as early as 1951 [1]. Ultrasound has potentially offered a non-invasive, in-line method of property and process monitoring [2,3]. Early research has demonstrated that viscosity measurement can be accomplished by ultrasound using different linear and nonlinear techniques [4]. This paper is devoted to furthering the technique called shear reflectance method [5]

The N-terminal domain of the Caulobacter crescentus CgtA protein does not function as a guanine nucleotide exchange factor

The Caulobacter crescentus GTP binding protein CgtA is a member of the Obg/GTP1 subfamily of monomeric GTP binding proteins. In vitro, CgtA displays moderate affinity for both GDP and GTP, and rapid exchange rate constants for either nucleotide. One possible explanation for the observed rapid guanine nucleotide exchange factor (GEF) rates is that CgtA is a bimodal protein with a C-terminal GTP binding domain and an N-terminal GEF domain. In this study we demonstrate that although the N-terminus of CgtA is required for function in vivo, this domain plays no significant role in the guanine nucleotide binding, exchange or GTPase activity. (C) 2000 Federation of European Biochemical Societies.link_to_subscribed_fulltex

Actively mode-locked fiber optical parametric oscillator

Active mode-locking of continuous wave pumped fiber optical parametric oscillators is reported. Stable 10 GHz pulses are obtained with tuning range of 21 nm. © 2009 IEEE.link_to_subscribed_fulltex