The broad spectral bandwidth of the excitation
pulses obviously promotes the feasibility of the observed two-photon channel. Theoretical estimates concerning the contribution of nonlinear absorbance strongly support the experimental findings. The essential conditions for proper utilization of this process are discussed. (C) 2010 American Institute of Physics. [doi:10.1063/1.3468632]“
“Poly(lactic acid), as a natural source polymer, was used to prepare pervaporation dense membranes. The performance of these membranes for the separation of the methanol (MeOH)/methyl tert-butyl ether (MTBE) mixtures was investigated. The effects of different operating conditions, including the feed concentration of MeOH, temperature, and flow rate, were examined. Several characterization tests were performed as well. The swelling results, scanning electron microscopy images, contact ARO 002 angles, and mechanical strength measurements are presented. These membranes were found to be selective to MeOH, particularly for traces of MeOH in MTBE with a separation factor of more than 30. There was a small decrease in the separation factor when the feed temperature was increased; meanwhile, the total flux increased to some extent. This could be explained AZD4547 with respect to the thermal motions of the polymer chains and the permeating molecules. With an increase in the feed flow rate,
both the selectivity and total flux increased because the concentration and temperature polarizations decreased. At higher flow rates, the feed components were homogeneously
distributed over the membrane surface, whereas there may have been a concentration or temperature gradient at lower flow rates. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 1364-1371, 2010″
“Enhancing waste activated sludge (WAS) anaerobic digestion by thermal pretreatment has become of high interest. However, thermal treatment has been mainly combined to mesophilic anaerobic digestion. This paper presents the combination of sludge thermal pretreatment (110, 165 and 220 Q and batch thermophilic anaerobic digestion (55 degrees C). Optimal conditions of thermal pretreatment were shown to be 165 degrees C, involving a chemical Vactosertib in vivo oxygen demand (COD) and volatile solids (VS) solubilisation of 18 and 15% and a biodegradability increase from 47 to 61%. Treatments at 165 C were carried out in electric and steam modes and no significant difference on the impact of heating mode oil sludge anaerobic biodegradability was observed. Moreover, it may be recommended not to carry Out Successive batch experiments to assess thermophilic BMP of sludge as accumulation of volatile fatty acids (VFA), particularly propionate, and a decrease of VFA uptake rates may occur. However, thermal pretreatment at 165 C allowed the decrease of propionate accumulation and an higher methane production. (C) 2009 Elsevier B.V. All rights reserved.