This was reacted with benzamide for the preparation of a model compound and with terephthalamide, isophthalmide, and adipamide for the preparation of polyamides in the presence of a mixture of 10 mol % CuI and 20 mol N,N’-dimethylethylenediamine as a catalyst and K(2)CO(3) as a base. The monomer and the model compound were characterized with Fourier transform infrared, proton nuclear magnetic resonance, and elemental analysis.
The prepared polyamides were characterized with Fourier transform infrared, proton nuclear magnetic resonance, differential scanning calorimetry, thermogravimetric analysis, and solubility and viscosity measurements. The obtained polyamides possessed excellent solubility in common organic solvents, and
they exhibited inherent viscosities in the range NU7026 of 0.93-1.19 dL/g. According to the differential scanning calorimetry analysis, the glass-transition temperatures of the polyamides were in the range of 89-154 degrees C. Thermogravimetric analysis indicated that a 2% weight loss of the polyamides occurred in the temperature Nocodazole cell line range of 218-253 degrees C under a nitrogen atmosphere. (C) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 111: 1588-1593, 2009″
“The enhancement of the efficiency in free-electron lasers (FELs) through the use of a tapered wiggler is well known. The physics of the tapered wiggler interaction has been studied in theory and simulation, and large efficiency enhancements have been observed in the laboratory in oscillators and seeded amplifiers. In this paper, we study the differences in the tapered wiggler interaction between seeded amplifiers and in FELs that start up from noise and grow to saturation in a single pass through the wiggler. This configuration is commonly referred to as self-amplified spontaneous emission (SASE). In comparison with seeded amplifiers, SASE FELs exhibit shot-to-shot fluctuations due
to random phase noise in the electron bunches, and our purpose in this paper is to determine the effect of this AZD5363 manufacturer phase noise on the tapered wiggler interaction. To this end, we study the interaction numerically using the MEDUSA simulation code for seeded and SASE FELs operating in the infrared regime. The results of the simulations indicate that the overall efficiencies of the seeded and SASE FELs are comparable for a uniform wiggler but that the output spectrum for the SASE FEL is much broader than for the seeded case. For a tapered wiggler, the efficiency enhancement in the SASE FEL is less than that found in the seeded example due to the broader excited spectrum that detunes the tapered wiggler interaction. (c) 2009 American Institute of Physics. [DOI: 10.1063/1.3131630]“
“BACKGROUNDHydrodynamic shear plays a major role in the formation, maintenance, structure, and metabolism of self-immobilized microbial communities in reactors.