Brno University of Technology

About: Brno University of Technology is a education organization based out in Brno, Czechia. It is known for research contribution in the topics: Fracture mechanics & Filter (video). The organization has 6339 authors who have published 15226 publications receiving 194088 citations. The organization is also known as: Vysoké učení technické v Brně & BUT.

Advances in wastewater nitrogen removal by biological processes: state of the art review

Abstract: O artigo resume o estado da arte dos mais recentes avancos na remocao biologica de nitrogenio, incluindo os criterios para o calculo do processo e as inovacoes tecnologicas. Em relacao ao processo Ludzck Ettinger modificado (pre-desnitrificacao, nitrificacao, no sistema de lodo activados), o qual e amplamente utilizado na remocao biologica de nitrogenio, foi proposta uma nova equacao para calcular o reactor de desnitrificacao, com base na taxa de desnitrificacao (SDNR-Specific Denitrification Rate). Alem disso, foram analisados os fatores que influenciam o SDNR (oxigenio dissolvido no reator; comportamento hidrodinâmico do reator) e foram propostas as solucoes tecnologicas. Quanto a evolucao tecnologica, o artigo apresenta um resumo dos varios processos de remocao biologica de amonia, que sao mais conhecidos com os nomes patenteados, tais como: ANAMMOX(r), DEMON(r), CANON(r), ANITA(r) e outros. Estes processos ja encontraram aplicacoes industriais no tratamento de aguas residuais de alta concentracao, tais como o licor de lodo digerido e o percolado de aterro sanitario. Entre as tecnologias emergentes de desnitrificacao foram considerados os bioreatores com membranas (MBfR), os quais podem ser operados tanto na fase aerobia quanto na fase anoxica.

Roadmap methods vs. cell decomposition in robot motion planning

Abstract: The task of planning trajectories plays an important role in transportation, robotics, information systems (sending messages), etc. In robot motion planning, the robot should pass around obstacles from a given starting position to a given target position, touching none of them, i.e. the goal is to find a collision-free path from the starting to the target position. Research on path planning has yielded many fundamentally different approaches to the solution of this problem that can be classified as roadmap methods (visibility graph method, Voronoi diagram) and methods based on cell decomposition. Assuming movements only in a restricted number of directions (eight directional or horizontal/vertical) the task, with respect to its combinatorial nature, can be solved by decomposition methods using heuristic techniques. We present drawbacks of this approach (combinatorial explosion, limited granularity and generating infeasible solutions). Then, using the Voronoi diagrams, we need only polynomial time for finding a solution and, choosing a Euclidean or rectilinear metric, it can be adapted to tasks with general or directional-constrained movements.

Mercury depth profiles in river and marine sediments measured by the diffusive gradients in thin films technique with two different specific resins

Abstract: The diffusive gradients in thin films technique (DGT) was used to measure depth profiles of mercury in river and marine sediments in situ to a spatial resolution of 0.5 cm. Agarose gel was used as the diffusive gel in the DGT probes. Two different selective resins—Chelex 100 with iminodiacetic groups and Spheron-Thiol with thiol groups incorporated in the polyacrylamide resin gel—- were tested. The different capture efficiencies of the two adsorbents enabled the fractions of mercury bound in different species in sediment pore water to be estimated. Mercury concentrations obtained by DGT with Spher- on-Thiol resin were very similar to those obtained after centrifugation. This indicates that DGT with Sheron- Thiol resin reports on total dissolved mercury levels. The concentration of mercury measured by DGT with Che- lex-100 resin was much lower (by a factor of 5-20) for the same sediment samples. Chelex-100 does not have such a high affinity to mercury as Spheron-Thiol, and so it only reports on the content of labile mercury species, such as inorganic ions and weak complexes. The content of labile mercury species in the river sediment was approximately 20% of the total dissolved mercury in pore water, whereas in marine sediment only 7% of the mercury was present as labile species.

A route toward more selective and less humidity sensitive screen-printed SnO2 and WO3 gas sensitive layers

Abstract: We have studied the effect of adhesion promoters (bismuth and copper oxides) on the gas sensing properties of screen-printed tin and tungsten oxide sensors. The gas-sensitive pastes were prepared by mixing either tin or tungsten oxide powders with an organic vehicle based on therpineol. Two different additives to enhance the adhesion of the active films to the substrate (Bi 2 O 3 or Bi 2 O 3 +Cu 2 O) were included in the paste composition. The films that resulted after printing and firing have high porosity and excellent adherence. Morphology studies have shown that the films have well-defined microstructure and gas sensitivity studies have shown that additives, not only help in promoting film adhesion, but also modify the response of the sensors. Their sensitivity at different operating temperatures was evaluated for ammonia, nitrogen dioxide, ethanol, benzene, carbon monoxide, methane and water vapour. It was found that WO 3 sensors containing Bi 2 O 3 and Cu 2 O were always more sensitive to ammonia and, that WO 3 sensors containing Bi 2 O 3 only were more sensitive to nitrogen dioxide when operated at 250 °C. The reaction paths that explain the sensitivity changes observed by the inclusion of Cu 2 O in tungsten oxide sensors are introduced and discussed.