Application of solid-phase microextraction-gas chromatography-mass spectrometry to characterize intermediates in a joint solar-microbial process for total mineralization of Aroclor 1254

A combined solid-phase microextraction-GC-MS analytical technique was used to monitor the formation of metabolites in the biodegradation of biphenyl, which were originally obtained from the solar photodechlorination of Aroclor 1254 by Pseudomonas pseudoalcaligenes KF707 and Burkholderia sp LB400. In both cases, the following metabolites were detected: 2-hydroxybiphenyl (2-OH-BP), 2,3-dihydroxybiphenyl (2,3-di-OH-BP), and benzoic acid, which was detected as its benzoate derivative 1-methylethylbenzoate. A time course study for the formation and disappearance of these metabolites was used to construct a degradation pathway, which in both cases, involved the formation of 2-OH-BP and 2,3-di-OH-BP.     

Ftir study of the protonation of a retinyl schiff base in chloroform/methanol mixtures

Fourter transform infrared spectra of a retinyl Schiff base in the presence of one of a series of acids were recorded in solvents containing chloroform and methanol in different proportions. The spectra show that methanol makes it possible for weak acids to achieve complete protonation of the Schiff base. This leads to the hypothesss that water or other OH containing molecules could play a role in bringing about complete protonation of the Schiff base chromophore in rhodopsins.     

Decay rates of the solution of the Cauchy thermoelastic Bresse system

We consider two Cauchy problems for the one-dimensional thermoelastic Bresse model. Using the energy method in the Fourier space, we show that for the first model, the \({L^{2}}\)-norm of the solution decays with the rate \({(1+t)^{-1/12}}\). In addition, the same decay rate has been obtained for the second model.     

Asynchronous multisplitting methods for nonlinear fixed point problems

Our aim is to present for nonlinear problems asynchronous multisplitting algorithms including both the basic situation of O'Leary and White and the discrete analogue of Schwarz's alternating method and its multisubdomain extensions and moreover their two-stage counterparts. The analysis of these methods is based on El Tarazi’s convergence theorem for asynchronous iterations and leads to a good level of asynchronism in each of the considered situations. This revised version was published online in August 2006 with corrections to the Cover Date.