12,659 research outputs found

    Combining high-value biotechnological processes: from wastewaters bioremediation to bacterial bioenergy feedstock production

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    Book of Abstracts of CEB Annual Meeting 2017[Excerpt] The significant increase of global industrialization has been promoting the generation of large amounts of residues and wastewaters. In particular, oily wastewaters (contaminated with hydrocarbons) must be considered, since their disposal into the surrounding environments can represent a serious threat to several types of environmental resources. Simultaneously, the drastic depletion of fossil fuel resources demands for search of alternative feedstocks with environmental and economic advantages. Therefore, the production of bacterial lipids using inexpensive substrates, as wastes, has attracted much attention. Hydrocarbonoclastic bacteria are important players in bioremediation of hydrocarbon contaminated wastewaters with additional capacity for the accumulation of storage lipids such as triacylglycerols and wax esters [1, 2]. These compounds are relevant raw materials for biofuels and oleochemicals production. [...]info:eu-repo/semantics/publishedVersio

    Interplay between disorder, quantum and thermal fluctuations in ferromagnetic alloys: The case of UCu2Si(2-x)Ge(x)

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    We consider, theoretically and experimentally, the effects of structural disorder, quantum and thermal fluctuations in the magnetic and transport properties of certain ferromagnetic alloys.We study the particular case of UCu2Si(2-x)Ge(x). The low temperature resistivity, rho(T,x), exhibits Fermi liquid (FL) behavior as a function of temperature T for all values of x, which can be interpreted as a result of the magnetic scattering of the conduction electrons from the localized U spins. The residual resistivity, rho(0,x), follows the behavior of a disordered binary alloy. The observed non-monotonic dependence of the Curie temperature, Tc(x), with x can be explained within a model of localized spins interacting with an electronic bath whose transport properties cross-over from ballistic to diffusive regimes. Our results clearly show that the Curie temperature of certain alloys can be enhanced due to the interplay between quantum and thermal fluctuations with disorder.Comment: 4 pages, 3 figures, to appear in Phys. Rev. Let

    Energy performance analysis between two air conditioning systems used in an educational Building in warm-climate

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    Energy saving measures, in the design air conditioning systems, are crucial in the development of energy schemes with rational energy consumption. Traditionally, integrated buildings systems have been assessed individually to optimize the energy performance, however they have different parameters that affect energy performance that demands the use of detailed analysis using dynamic simulation. This paper is focused on compare an air conditioning system to be implemented in educational buildings in warm-climate, considering energy schemes provide for a constant air volume (CAV) flow system with a water chiller, while the other integrates a variable refrigerant flow (VRF) system. Adding in each case dedicated outdoor air System (DOAS) units. Energy consumption achieved by each AC system is obtained considering the configuration achieving energy savings of 40% of the annual electricity demand for cooling. Finally, the use of DOAS represents an increase of 20% of total electricity consumption

    Negative Hopping Magnetoresistance and Dimensional Crossover in Lightly Doped Cuprate Superconductors

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    We show that, due to the weak ferromagnetism of La2x_{2-x}Srx_xCuO4_4, an external magnetic field leads to a dimensional crossover 2D \to 3D for the in-plane transport. The crossover results in an increase of the hole's localization length and hence in a dramatic negative magnetoresistance in the variable range hopping regime. This mechanism quantitatively explains puzzling experimental data on the negative magnetoresistance in the N\'eel phase of La2x_{2-x}Srx_xCuO4_4.Comment: 6 pages, 3 figures; published versio

    Ocorrência de Dichomeris famulata Meyrick (Lepidoptera: Gelechiidae) na cultura de milho orgânico solteiro ou consorciado com feijão.

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    A lagarta de Dichomeris famulata (Lepidoptera: Gelechiidae) danifica os grãos e compromete a germinação da semente. Sua ocorrência em milho no Brasil, especialmente em milho orgânico não tem sido evidenciada. No entanto, observações de campo têm sugerido que a praga pode tornar um problema real para o agricultor. Este trabalho teve como objetivo avaliar. a ocorrência da praga em espigas de milho cultivado no sistema orgânico. solteiro ou consorciado com feijão. No consórcio milho/feijão a ocorrência de D. famulata foi menor do que no sistema solteiro. porém sua presença foi constante em todas as avaliações. indicando de fato que o inseto pode vir a ser uma praga importante para o milho orgânico

    Vibrational analysis and thermal behavior of salvia hispanica, nigella sativa and papaver somniferum seeds

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    Introduction: Salvia hispanica L., Nigella sativa L. and Papaver somniferum L. are involved in opiate-dependent behavior. It is known that the seeds of these three herbs contain high amounts of antioxidants, which are helpful in disease prevention, but further research is needed on some of their other phytochemical components (terpene alkaloids, benzoquinones and others), which are claimed to affect human opioid receptors. Methods: Seeds from the three afore mentioned plants have been studied by ATR-FTIR vibrational spectroscopy and thermo analytical techniques (TG/DTG, DTA and DSC). Results: The infrared spectrum has confirmed the presence of the ester carbonyl of terpenoid alkaloids (such as nigellamine) and the fully conjugated cyclic dione structure of quinones (e.g., thymoquinone). As regards the thermal stability of these seeds, small differences have been observed in their thermal profiles (endothermic effects at around 333C for chia, 268C for black cumin and 319C for poppy seeds), which can be ascribed to their different content in carbohydrates. Conclusions: The functional groups of the main active constituents and the thermal behavior of these three seeds have been elucidated
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