2 MPa) and elongation (300% +/- 50%). The strength of the web was high enough to use as filter without the need of any supporting matrix and could be applicable in the field of self-supporting membranes. The X-ray and DSC analyses of the PA 6 electrospun fibers show the presence
of the gamma-form of PA 6 crystallite that is usually obtained in the condition selleck screening library where a high stress of the fibers is applied. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 1754-1765, 2010″
“We evaluate the sensitivity of multimodal nonlinear resonance spectroscopy to torque changes in a threaded interface. Our system is comprised of a bolt progressively tightened in an aluminum plate. Different modes of the system are studied in the range 1-25 kHz, which MEK activation correspond primarily to bending modes of the plate. Nonlinear parameters expressing the importance of resonance frequency and damping variations are extracted and compared to linear ones. The influence of each mode shape on the sensitivity of nonlinear parameters is discussed. Results suggest that a multimodal measurement is an appropriate and sensitive method for monitoring bolt tightening. Further, we show that the nonlinear components
provide new information regarding the interface, which can be linked to different friction theories. This work has import to study of friction and to nondestructive evaluation of interfaces for widespread application and basic research. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3443578]“
“The thermodynamic study of the sulphonation of polystyrene-butadiene rubber (PSBR) with chlorosulphonic acid for fuel cell application was carried out. This was done to understand the properties of the sulphonation process in terms of the change in enthalpy (Delta H), entropy (Delta S), and the Gibbs free energy (Delta G) relative to product stability. The Delta H(0), Delta S(0), and Delta G(0) were found to be 40.708 kJ, 64.22 J K(-1), and 22.916 kJ, respectively, indicating that the reaction is not thermodynamically
favorable (though non-sponteneous) where products are less favored compared to reactants which thus required energy. However, at elevated temperature (>328 K), a phase change from liquid to solid was encountered which suggests that the optimum temperature to carry out the Rigosertib chemical structure sulphonation of PSBR in chlorosulphonic acid should be within 328 K. Results obtained also revealed that the sulphonation time influenced the qualities such as, proton conductivity, degree of sulphonation, and methanol permeability of the sulphonated PSBR. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 1766-1771, 2010″
“The three-dimensional structures of proteins are stabilized by the interactions between amino acid residues. Here we report a method where four distances are calculated between any two side chains to provide an exact spatial definition of their bonds.