Whereas the critical value D(c)(loc) for local stability may be discontinuous across a magnetic phase boundary, the critical value D(c)(glo) >= D(c)(loc) for global stability must be continuous. We demonstrate this behavior across the phase boundary between collinear three and four sublattice phases that are stable for large D. (C) 2011 American Institute of Physics. [doi:

10.1063/1.3553780]“
“A new ionic polyacetylene was prepared by the activation polymerization of 2-ethynylpyridine with 2-(bromomethyl)-5-nitrofuran https://www.selleckchem.com/products/acy-738.html in high yield without any additional initiator or catalyst. This polymerization proceeded well in a homogeneous manner to give a high yield of the polymer (92%). The activated acetylenic triple bond of N-(5-nitro-2-furanmethylene)-2-ethynylpyridinium bromide, formed in the first quaternerization process, was found to be susceptible to linear polymerization. This polymer was completely soluble in such polar organic solvents as dimethylformamide, dimethyl sulfoxide, and N,N-dimethylacetamide. The inherent check details viscosities of the resulting polymers were in the range 0.12-0.19 dL/g, and X-ray diffraction analysis data indicated that

this polymer was mostly amorphous. The polymer structure was characterized by various instrumental methods to have a polyacetylene backbone structure with the designed substituent. The photoluminescence peak was observed at 593 nm; this corresponded to a photon energy of 2.09 eV. The polymer exhibited irreversible electrochemical behaviors between the doping and undoping peaks. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 122: 987-992, 2011″
“Oxygen transfer was evaluated in three internal-loop

airlift reactors (ALRs) of different working volumes (2, 5, and 10 dm(3)) and similar geometric configuration utilizing eight Newtonian and five non-Newtonian fluids. The effects of the superficial gas velocity (U(GR)) and liquid viscosity (mu(L)) had opposite effects on the volumetric oxygen transfer coefficient (k(L)alpha). However, they presented the same orders of magnitude showing that the viscosity MX69 price effect on oxygen mass transfer cannot be neglected. A correlation for k(L)alpha based on dimensional analysis considering the effects of the geometric parameters, the physical properties of the fluid, and the operational conditions presented a very good fitting to the experimental data. The correlation shows that the influence of the reactor internal diameter on k(L)alpha was considered positive. Therefore, in larger-scale reactors an appropriate oxygen transfer can be reached under smaller aeration conditions. (C) 2010 Elsevier B.V. All rights reserved.