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Filteraids are used in challenging filtration applications, suchas the deliquoring of biomass suspensions and separation of fine particlesfrom liquids. Organic filter aids, typically composed of cellulose,may be the preferred option in the case of bioprocesses because theirenergy content can be recovered together with the primary filter cake.In this study, a laboratory-scale pressure filter was used in orderto investigate the effect of various filter aids on the filtrationof an enzymatically hydrolyzed biomass suspension. Various organicand inorganic filter aids were used in two modes: as a body feed andas a precoat. According to the results, the average specific resistanceof the cakes could be best reduced using the body feed mode. Filteraids also helped to reduce the moisture content of the cakes and toincrease the corresponding filtration capacities. Additionally, aprocess scheme enabling utilization of the solids was proposed. [ABSTRACT FROM AUTHOR]

AbstractWe present a delayed stochastic model of transcription at the single nucleotide level. The model accounts for the promoter open complex formation and includes alternative pathways to elongation, namely pausing, arrest, misincorporation and editing, pyrophosphorolysis, and premature termination. We confront the dynamics of this detailed model with a single-step multi-delayed stochastic model and with measurements of expression of a repressed gene at the single molecule level. At low expression rates both models match the experiments but, at higher rates the two models differ significantly, with consequences to cell-to-cell phenotypic variability. The alternative pathway reactions, due to, for example, causing polymerases to collide more often on the template, are the cause for the difference in dynamical behaviors. Next, we confront the model with measurements of the transcriptional dynamics at the single RNA level of an induced gene and show that RNA production, besides its bursting dynamics, also exhibits pulses (2 or more RNAs produced in intervals smaller than the smallest interval between initiations). The distribution of occurrences and amplitudes of pulses match the experimental measurements. This pulsing and the noise at the elongation stage are shown to play a role in the dynamics of a genetic switch. [ABSTRACT FROM AUTHOR]