1,713 research outputs found
Experiments on computer assisted optimization of the escherichia coli fermentation process using Optferm
We used the software Optferm to model and optimize the bioprocess of escherichia coli fermentation, simulating the conditions of a fed-batch bioreactor. The results, obtained by employing different AI approaches, provided useful orientation for nutrient feed strategies for increased productivity. In conclusion, we believe in silico tools can perform a rapid and valid optimization of bioprocesses avoiding expensive experiments
Controls on Quaternary coastal evolution of the East-Northeastern coast of Brazil : roles of sea-level history, trade winds and climate
Power outage detection methods for theoperation of a shunt active power flter as energy backup system
This paper presents the study of power outage detection methods that can be applied to a Shunt Active Power Filter (SAPF) with energy backup capability. SAPFs can successfully compensate Power Quality problems related with distorted or unbalanced currents and low power factor. Future Smart Grids will combine devices, control strategies and functionalities to increase the grid reliability and the power management capability. One of the main tools necessary to enable these features is the information of what is occurring in all the smart grid parts. In this context the fast detection of power outages is critical, so this paper also contributes for the discussion of the best ways to extract information in the context of future smart grids. The combination of information and flexible devices in a smart grid will enable the implementation of collective awareness systems, which can deal with different electrical grid problems and situations in an organic manner.This work is financed by FEDER Funds, through the Operational Programme for Competitiveness Factors – COMPETE, and by National Funds through FCT – Foundation for Science and Technology of Portugal, under the projects FCOMP 01-0124-FEDER-022674 and PTDC/EEA-EEL/104569/2008. Bruno Exposto is supported by the doctoral scholarship SFRH/BD/87999/2012 granted by FCT – Foundation for Science and Technology of Portugal.
0info:eu-repo/semantics/publishedVersio
Mapa geologico do quaternario costeiro do estado da Bahia : escala 1/250 000 : texto explicativo
Decennial comparison of changes in social vulnerability: a municipal analysis in support of risk management
The concept of Social Vulnerability (SV) is characterized and distinguished by its complexity and multidisciplinarity. This concept takes into account the specific characteristics of the individual and his social and economic relations, as well as the physical environment where he is inserted. These differentiating characteristics make Social Vulnerability (SV) an indispensable work tool in the process of characterizing and understanding the degree of exposure of communities, as well as evaluating their capacity for resilience and recovery from hazardous events.
This paper presents a comparison between the SV performed in 2008 with the results obtained in 2017 for the 278 municipalities of mainland Portugal. The methodology was based on the work developed by the Center for Social Studies of the University of Coimbra, which is distinguished by the fact that SV is composed of two components: Criticity and Support Capability. The analysis of SV and its components was done using Principal Components Analysis (PCA) starting from an initial set of 235 variables (90 for Criticality and 145 for Support Capability).
With respect to Criticality, the results point out the importance of factors related to the economic condition, employment and factors related to the disadvantaged population and risk groups. Support Capability is strongly influenced by the population density and the most relevant factors for the final results are those related to civil protection response, economic and environmental dynamism and logistic and service capacity. Regarding the SV spatial distribution, the highest values are located mainly in the central and northern parts of the country, with emphasis on the Douro river valley and surrounding municipalities; also a general decrease of SV was recorded in the southern regions from 2008 to 2017.info:eu-repo/semantics/publishedVersio
Growth of CaF2 buffer on Si using low energy cluster beam deposition technique and study of its properties
International audienc
Growth of CaF2 buffer on Si using low energy cluster beam deposition technique and study of its properties
General dissipation coefficient in low-temperature warm inflation
In generic particle physics models, the inflaton field is coupled to other
bosonic and fermionic fields that acquire large masses during inflation and may
decay into light degrees of freedom. This leads to dissipative effects that
modify the inflationary dynamics and may generate a nearly-thermal radiation
bath, such that inflation occurs in a warm rather than supercooled environment.
In this work, we perform a numerical computation and obtain expressions for the
associated dissipation coefficient in supersymmetric models, focusing on the
regime where the radiation temperature is below the heavy mass threshold. The
dissipation coefficient receives contributions from the decay of both on-shell
and off-shell degrees of freedom, which are dominant for small and large
couplings, respectively, taking into account the light field multiplicities. In
particular, we find that the contribution from on-shell decays, although
Boltzmann-suppressed, can be much larger than that of virtual modes, which is
bounded by the validity of a perturbative analysis. This result opens up new
possibilities for realizations of warm inflation in supersymmetric field
theories.Comment: 25 pages, 13 figures; revised version with new results added;
published in JCA
Avaliação da atividade antioxidante e citotóxico in vitro do óleo essencial de curcuma zedoaria (christm.) Roscoe / Evaluation of in vitro antioxidant and cytotoxic activity of curcuma zedoaria (christm.) Roscoe Essential oil
Curcuma zedoaria (Christm.) Roscoe é uma planta herbácea e rizomatosa da família Zingiberaceae. As folhas e os rizomas do gênero Curcuma são fontes de óleos essenciais utilizados na indústria química, farmacêutica e de alimentos devido a sua ação antioxidante. O óleo essencial de Curcuma zedoaria possui potente atividade citotóxica, antioxidante e inibe a proliferação celular de diversos tipos de cânceres. Apesar da sua importância biológica e econômica verificamos ausência na literatura de ensaios in vitro com método de difusão em culturas de Escherichia coli BW9091 e AB1157 sob a ação de agentes oxidantes (SnCl2 e H2O2) que atacam o DNA cromossômico e nucleotídeos livres e de estudos que descrevam a ação do óleo essencial com o antibiótico amoxicilina. Vale ressaltar que as cepas Escherichia coli AB1157 e BW9091 apresentam, respectivamente, todos os mecanismos de reparos funcionantes para o reparo de DNA e uma deficiência na exonuclease III (xthA-), isto é, deficiência nos sistemas envolvidos na correção de danos oxidativos do DNA por excisão de bases (BER). Já o antibiótico amoxicilina tem mobilizado a atenção e preocupação em serviços hospitalares devido ao aumento de casos de resistência microbiana. Verificou-se, neste estudo que óleo essencial de Curcuma zedoaria inibiu as cepas Escherichia coli BW9091 nas concentrações de 12 e 24 L. Contudo, a diferença na concentração foi, ligeiramente, mais perceptiva em Escherichia coli AB1157 (p<0,001) do que com a Escherichia coli BW9091 (p<0,01). É provável que a presença do gene mutante na cepa Escherichia coli BW9091 tenha promovido um aumento da resistência ao efeito inibitório do óleo essencial. Verificamos que o óleo essencial de Curcuma zedoaria nas concentrações de 24 e 12 µL apresentou potencial inibitório em ambas as cepas de Escherichia coli. Verificou-se, em Escherichia coli AB 1157, que a associação entre o óleo essencial e amoxicilina na concentração de 12 µL apresentou um halo de inibição maior do que quando administrado com o antibiótico isolado. O teste Turkey Kramer demonstrou que houve uma diferença significativa (p<0.001) entre as médias desses halos. A associação de óleo essencial com o cloreto estanoso 12 µL teve seu efeito citotóxico potencializado com ambas as cepas. Entretanto, em Escherichia coli AB 1157 o halo de inibição foi menor, demonstrando que o óleo essencial pode exercer um efeito sinérgico quando associado ao cloreto estanoso. Vale a pena ressaltar que essas diferenças foram significativas (p<0.01) tanto para a Escherichia coli AB1157 e BW9091. Já no controle positivo do peróxido de hidrogênio (H2O2) + 12 µL do óleo essencial observamos aumento na ação oxidativa na cepa AB1157. Portanto, concluímos que o óleo essencial tem potencial farmacológico como princípio ativo natural; exerceu atividades antioxidante e antimicrobiana sobre as cepas de Escherichia coli testadas e potencializou o efeito inibitório quando associado ao antibiótico amoxicilina
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