No abstract

No abstract

SUMMARYWaveforms arising from power electronics circuits often contain slowly changing segments with highfrequency details concentrated near the switching instants. Such a feature is consistent with the localization property of wavelets which are known in the signal processing literature to be highly suitable for describing fast changing edges embedded in slowly varying backgrounds. This paper considers the application of wavelet approximation to the steady-state analysis of power electronics circuits. The basic procedure of wavelet approximation is reviewed, and an improved approach by mixing wavelets of di erent levels is described. When applied to power electronics circuits, the method yields e cient solutions because only a relatively small number of wavelets are needed and the proposed algorithm involves only matrix operations, permitting the steady-state waveforms to be found fast.

No abstract

Fiber curls, kinks, microcompressions, nodes, crimps, and dislocations have been frequently associated with weak points in biomass fibers that exhibit increased accessibility to enzymes and chemicals. Rapid measurements using fiber quality analysis (FQA) showed that the curl and kink indices were increased by 300% in fibers that were processed at high solids loadings, but these indices were readily reversed by the application of a “straightening” treatment to the fibers. The curlation of fibers increased their susceptibility to shortening when they were exposed to endoglucanases and hydrochloric acid. Increased fiber curl also enhanced cellulose accessibility as measured by Simons staining (SS) and water retention value (WRV) and resulted in the formation of fiber networks with increased bulk. Upon straightening the fibers, these effects were reversed, with the exception of the increases in cellulose accessibility measured by SS and WRV. The induction of fiber curls and kinks also resulted in irreversible increases in cellulose hydrolysis yields of up to 17% that were more pronounced at higher solids loadings. The better hydrolysis at higher solids loadings was likely due to the well-known tendency of curled fibers to form bulkier fiber networks with decreased fiber bonding. The results suggest that it should be possible to simultaneously increase cellulose accessibility when hydrolysis is performed at high solids loadings by the application of appropriate physical treatments. It was apparent that the increased cellulose accessibility measured by SS and WRV and reflected by the enhancement in enzymatic hydrolysis yields was a byproduct of curl and kink induction and thus was not directly measurable using an FQA.

No abstract

This is a repository copy of Rewetting global wetlands effectively reduces major greenhouse gas emissions.

A “one-pot” approach using alkaline-oxygen modified lignin, maximized carbohydrate recovery and increased hydrolysis yields of mechanical pulp more effectively than a pre-hydrolysis approach.