However, the fluid consistency appears not to be affected selleck products by the presence of starch. It is also concluded that the presence of glass bubbles, xanthan gum, and clay in the fluid tends to determine the final fluid to behave as pseudoplastic. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012″
“A bottom-gate, bottom-contact (BGBC) organic thin-film transistor (OTFT) with carrier-doped regions over source-drain electrodes was investigated. Device simulation with our originally developed device simulator demonstrates that heavily doped layers (p(+) layers) on top of the source-drain contact region can compensate the deficiency of charge carriers at the source-channel interface
during transistor operation, leading to the increase of the drain current and the apparent field-effect mobility. The phenomena expected with the device simulation were experimentally confirmed in typical BGBC pentacene thin-film transistors. The 5-nm-thick p(+) layers, located 10 nm (or 20 nm) over the source-drain electrodes, were prepared by coevaporation of pentacene and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane as an acceptor dopant. Since selleck screening library the molecular doping in this study can increase the drain current without positive
shift of threshold voltage, p(+) layers were formed precisely on top of the source-drain regions. This study shows that common inferior characteristics of bottom-contact OTFT devices mainly derive from the supply shortage of charge carriers to the channel region. The importance of reliable molecular doping techniques or heavily doped semiconductor materials for improving OTFT device performance is clearly suggested. (C) 2011 American Institute of Physics. [doi:10.1063/1.3627240]“
“Adaptation in spatially extended populations entails the propagation of evolutionary novelties across habitat ranges. Driven by natural selection, beneficial mutations
sweep through the population in a “”wave of advance”". The standard model for these traveling waves, due to R. Fisher and A. Kolmogorov, plays an important role in many scientific areas besides evolution, such as ecology, epidemiology, AZD6094 research buy chemical kinetics, and recently even in particle physics. Here, we extend the Fisher-Kolmogorov model to account for mutations that confer an increase in the density of the population, for instance as a result of an improved metabolic efficiency. We show that these mutations invade by the action of random genetic drift, even if the mutations are slightly deleterious. The ensuing class of noise-driven waves are characterized by a wave speed that decreases with increasing population sizes, contrary to conventional Fisher-Kolmogorov waves. When a trade-off exists between density and growth rate, an evolutionary optimal population density can be predicted.