Biofilm reactor technology as an alternative to control fungal filamentous bulking caused by Galactomyces geotrichum

The present work aims to evaluate a strategy for solving fungal filamentous bulking caused by Galactomyces geotrichum. For this study, four sequencing batch reactors (SBR) fed with acetate were operated without (SBR1) and with support for biofilm growth [5 % (SBR2), 10 % (SBR3) and 20 % (SBR4) of the reactor volume]. The results demonstrated an overabundance of G. geotrichum in the SBR operating just with suspended biomass. The incorporation of an optimized amount of support for biofilm growth (10 %) seemed to suppress the overgrowth of the G. geotrichum filaments probably due to the combined effect of a decreased biomass loading and an increased shear force

Análise de tendências na temperatura do ar e na precipitação pluvial na região de Passo Fundo, RS.

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Flat-band induced local Hilbert space fragmentation

We demonstrate that a complete class of flat-band lattices with underlying commutative local symmetries exhibit a locally fragmented Hilbert space. The equitable partition theorem ensures distinct parities for the compact localized states (CLSs) present in this class of flat-band lattices and the extended eigenstates of the system. In the presence of on-site bosonic interactions, such models exhibit a conserved quantity, the parity of the number of particles located in all the CLSs in a unit cell. As a consequence, the Hilbert space presents local fragmentation, which is only revealed upon rotating the basis of the Hamiltonian that decouples the CLSs at the single-particle level. We find that the fragmentation is strong and also robust to the addition of long-range interactions. As an example, we numerically analyze the fragmentation of the one-dimensional Pyrochlore chain, which exhibits both nonintegrable sectors, effective single-particle sectors, and frozen states. We also show that the entanglement entropies form a nested-dome structure typical of these fragmented systems and that thermalization is restricted to each sub-sector.Comment: 10 pages, 2 figure

Autonomous Light Management in Flexible Photoelectrochromic Films Integrating High Performance Silicon Solar Microcells

Commercial smart window technologies for dynamic light and heat management in building and automotive environments traditionally rely on electrochromic (EC) materials powered by an external source. This design complicates building-scale installation requirements and substantially increases costs for applications in retrofit construction. Self-powered photoelectrochromic (PEC) windows are an intuitive alternative wherein a photovoltaic (PV) material is used to power the electrochromic device, which modulates the transmission of the incident solar flux. The PV component in this application must be sufficiently transparent and produce enough power to efficiently modulate the EC device transmission. Here, we propose Si solar microcells (μ-cells) that are i) small enough to be visually transparent to the eye, and ii) thin enough to enable flexible PEC devices. Visual transparency is achieved when Si μ-cells are arranged in high pitch (i.e. low-integration density) form factors while maintaining the advantages of a single-crystalline PV material (i.e., long lifetime and high performance). Additionally, the thin dimensions of these Si μ-cells enable fabrication on flexible substrates to realize these flexible PEC devices. The current work demonstrates this concept using WO₃ as the EC material and V₂O₅ as the ion storage layer, where each component is fabricated via sol-gel methods that afford improved prospects for scalability and tunability in comparison to thermal evaporation methods. The EC devices display fast switching times, as low as 8 seconds, with a modulation in transmission as high as 33%. Integration with two Si μ-cells in series (affording a 1.12 V output) demonstrates an integrated PEC module design with switching times of less than 3 minutes, and a modulation in transmission of 32% with an unprecedented EC:PV areal ratio

Troubleshooting of filamentous bulking using hybdrid systems

The present work aims to evaluate filamentous bulking control in hybrid systems. For this study, four sequencing batch reactors (SBR) fed with acetate were operated without (SBR1) and with support for biofilm growth [5 % (SBR2), 10 % (SBR3) and 20 % (SBR4) of the reactor volume]. The results demonstrated an overabundance of a filamentous fungi-like microorganism in the SBR operating just with suspended biomass. The incorporation of an optimized amount of support for biofilm growth (10 % and 20 %) seemed to suppress the overgrowth of this filamentous microorganism probably due to the combined effect of a decreased biomass loading rate and the physical cut or breakdown of filaments induced by support-to-support collisions

Troubleshooting of filamentous bulking using biofilm reactors

The present work aims to evaluate filamentous bulking control in systems combining suspended biomass with biofilm growth. For this study, four sequencing batch reactors (SBR)fed with an easy biodegradable substrate (acetate) were operated without (SBR1) and with support for biofilm growth [5 % (SBR2), 10 % (SBR3) and 20 % (SBR4) of the reactor volume]. The results demonstrated an overabundance of a filamentous fungi-like microorganism in the SBR operating just with suspended biomass. The incorporation of an optimized amount of support for biofilm growth (10 % and 20 %) seemed to suppress the overgrowth of this filamentous microorganism probably due to the combined effect of a decreased biomass loading rate and the physical cut or breakdown of filaments induced by particle-to-particle collisions. Besides the observed differences in terms of the filamentous fungi-like microorganism, the incorporation of a support material for biofilm growth was also found to induce increasing differences in the bacterial community structure as the concentration of support increased in the SBR

Influence of carrier concentration on the control of Galactomyces geotrichum bulking and bacterial community of biofilm reactors

The present work aims to evaluate a strategy to solve Galactomyces geotrichum bulking based on the incorporation of a biofilm carrier in activated sludge systems. For this study, four sequencing batch reactors (SBR) were operated without (SBR1) and with a carrier for biofilm growth (5% [SBR2], 10% [SBR3], and 20% [SBR4] of the reactor volume). As expected, G. geotrichum bulking was observed in the SBR operating just with suspended biomass, as ascertained by direct microscopic inspection. The incorporation of an optimized amount of biofilm carrier (10 and 20%) suppressed the overgrowth of the filamentous fungus probably due to the combined effect of a decreased biomass loading rate and an increased shear stress. Polymerase chain reaction—denaturing gradient gel electrophoresis (PCR–DGGE) analysis of the bacterial community suggested that the incorporation of a biofilm carrier induced increasing differences in the bacterial community structure as the concentration of carrier increased in the SBR. However, the observed differences did not seem to affect the activated sludge system since bacterial groups usually present in these systems prevailed.The work described in this paper was financially supported by FCT-Foundation for Science and Technology (Portugal)-by the PhD student grant SFRH/BD/44596/2008

Estudos preliminares da associação de gluteninas de alto peso molecular e parâmetros de qualidade tecnológica de trigo.

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Growth of Galactomyces geotrichum in sequencing batch reactors under different organic loading conditions

The present work aims to study the effect of the organic loading rate on the growth of filamentous fungi. For this purpose, three sequencing batch reactors (SBR), fed with an easy biodegradable substrate (acetate), were operated at different organic loading rates: 4.3 g COD L -1 day-1 (SBR1), 1.0 g COD L-1 day-1 (SBR2) and 0.5 g COD L-1 day-1 (SBR3). High amounts of fungal filaments were observed in the SBR operating at higher organic loading rate, as ascertained by direct microscopic inspection, while, at lower organic loading rates, overabundance of fungal filaments was not observed. Sequence retrieved from the isolated fungal filaments presented high similarity (99 %) to Galactomyces geotrichum