3,137 research outputs found

    Comparison between the numerical solutions and the Thomas-Fermi approximation for atomic-molecular Bose-Einstein condensates

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    We study the stationary solution of an atomic Bose-Einstein condensate coupled coherently to a molecular condensate with both repulsive and attractive interspecies interactions confined in an isotropic harmonic trap. We use the Thomas-Fermi approximation and find four kinds of analytical solution for the cases. These analytical solutions are adopted as trial function for the diffusive numerical solution of the Gross-Pitaevskii equations. For the repulsive interspecies interaction, the case in which the atomic and molecular wavefunctions are out-phase, the densities have similar profiles for both methods, however, the case where the wavefunctions are in-phase, there are considerable difference between the density profiles. For the attractive interspecies interaction, there are two cases in the Thomas Fermi approximation where the wavefunctions are in-phase. One of them has numerical solution that agree with the approximation and the other does not have corresponding numerical solution.Comment: 15 pages, 6 figure

    Additive manufacturing of bioactive glass in a biodegradable matrix

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    Bioactive glass can induce a specific and fast response in the human body that supports tissue regeneration. It is possible to control the design of customized bioapplications with advanced technologies. Although currently used in research, only a few of these technologies have been approved by the FDA to be applied in Tissue Engineering. There is dedicated additive manufacturing equipment to manufacture biomaterials. Since they are emerging technologies in emerging fields of application it is necessary to study and develop formulations with suitable processing characteristics [1]. Formulations of bioactive glass (CaO·P2O5·MgO·SiO2 system) in two different biodegradable matrices (polylactide (PLA) and polycaprolactone (PCL)) were prepared and processed by material extrusion process, namely by Fused Filament Fabrication technique.. The polymer (PLA or PCL) involves bioactive particles in biocompatible media and allows to acquire extrudable skills. The formulations with different solid contents (20–50 wt.%) were prepared using a brabender mixer type and were characterized by different techniques (e.g., X-ray diffraction (XRD), differential scanning calorimetry (DSC), melt flow index (MFI)). The inorganic particles influence the rheological and thermal properties of bioactive glass composites. The viscosity decreases with the increase of bioactive glass content in the polymer matrix. Mechanical standard samples and scaffolds were printed and characterized. Bioactive glass composites until 40 wt.% of solid content can be printed. The bioactive glass improves the mechanical resistance of composites compared to a neat polymer matrix. However, formulations with high bioactive glass solid content (50 wt.%) showed printing limitations by their brittleness and clogging tendency.publishe

    Existe diferença de osmolaridade entre ejaculados de carneiros?

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    Apresentado no CONGRESSO NORTE NORDESTE DE REPRODUÇÃO ANIMAL, 7., 2014, Mossoró. Novos rumos para a reprodução animal no Norte e Nordeste do Brasil: anais. Mossoró, 2014

    Latest results from the EU project AVATAR: aerodynamic modelling of 10 MW wind turbines

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    This paper presents the most recent results from the EU project AVATAR in which aerodynamic models are improved and validated for wind turbines on a scale of 10 MW and more. Measurements on a DU 00-W-212 airfoil are presented which have been taken in the pressurized DNW-HDG wind tunnel up to a Reynolds number of 15 Million. These measurements are compared with measurements in the LM wind tunnel for Reynolds numbers of 3 and 6 Million and with calculational results. In the analysis of results special attention is paid to high Reynolds numbers effects. CFD calculations on airfoil performance showed an unexpected large scatter which eventually was reduced by paying even more attention to grid independency and domain size in relation to grid topology. Moreover calculations are presented on flow devices (leading and trailing edge flaps and vortex generators). Finally results are shown between results from 3D rotor models where a comparison is made between results from vortex wake methods and BEM methods at yawed conditions

    Uso de leguminosas na fitorremediação de solo contaminado com sulfentrazone.

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    RESUMO: Resíduos de sulfentrazone podem permanecer no solo por cerca de dois anos, oferecendo risco de contaminação a lençóis freáticos e possibilitando o cultivo de espécies susceptíveis. Diante disto, a fitorremediação pode representar uma opção para a descontaminação de áreas que sofreram com intensas aplicações deste herbicida. O presente trabalho avaliou o potencial remediador das espécies Crotalaria juncea, Canavalia ensiformis, Cajanus cajan e Cajanus cajan (anão), com relação ao herbicida sulfentrazone, utilizando-se o milheto (Pennisetum glaucum) como planta bioindicadora. O experimento foi instalado em casa-de-vegetação e os tratamentos compostos pela combinação entre as quatro espécies citadas, além da testemunha, e quatro doses de sulfentrazone (0 g i.a. ha-1, 200 g i.a. ha-1, 400 g i.a. ha-1 e 800 g i.a. ha-1). Foram avaliadas a altura de plantas, fitotoxicidade ao sulfentrazone e biomassa fresca e seca da parte aérea. Quando P. glaucum foi cultivado após C. juncea, apresentou maior ganho em biomassa e maior altura, e os sintomas de fitotoxicidade foram menos acentuados. C. juncea apresentou a maior capacidade de fitorremediar solos contaminados com sulfentrazone.ABSTRACT: Use of leguminous plants for phytoremediation of soil contaminated with sulfentrazone. Residual sulfentrazone may remain in the soil for around two years, being a source of groundwater contamination and preventing the growth of usceptible plants. So, phytoremediation may represent an option for decontaminating areas which were highly affected by applications of this herbicide. This study aimed at evaluating the potential of Crotalaria juncea, Canavalia ensiformis, Cajanus cajan and Cajanus cajan (dwarf) for remediation of soil contaminated with sulfentrazone, using millet (Pennisetum glaucum) as a bioindicator plant. The experiment was installed in a greenhouse and treatments consisted of the four species already mentioned, plus a control, and four sulfentrazone doses (0 g a.i. ha-1, 200 g a.i. ha-1, 400 g a.i. ha-1 and 800 g a.i. ha-1). Plants height, phytotoxicity to sulfentrazone and fresh and dry matter were evaluated. When P. glaucum was grown after C. juncea, the fresh and dry matter, as well as plant height, were higher, while the phytotoxicity symptoms were less evident. C. juncea showed the best results for phytoremediation of soils contaminated with sulfentrazone

    Influência de diferentes fontes de adubos nitrogenados na produção de grãos e nos crescimento de ramos de cafeeiro Conilon.

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    Com o objetivo de avaliar a influência de cinco fontes de adubos nitrogenados no crescimento de ramos e na produção de grãos do cafeeiro Conilon (Coffea canephora), foram comparados uréia perolada; Uréia + NBPT; uréia + 0,15% de cobre e 0,4% de boro; uréia (37%) + enxofre (17%) e nitrato de amônio. O estudo foi realizado no município de Nova Venécia - ES em uma lavoura de cafeeiro Conilon ?Vitória INCAPER 8142? clone 03 com espaçamento de três metros entre linhas e um metro entre plantas, em estádio de segundo ano de produção, seguindo o delineamento em blocos casualizados. Foi avaliado o crescimento dos ramos ortotrópicos e dos ramos plagiotrópicos em nove avaliações mensais. A produtividade do cafeeiro foi obtida em litros por planta de café maduro e extrapolada para sacas por hectare. Observou-se que não houve diferença estatística entre as diferentes fontes de adubos nitrogenados no crescimento de ramos do cafeeiro. Em relação à produtividade, observou-se que os tratamentos com uréia + 0,15% de cobre + 0,4% de boro e o tratamento com uréia (37%) + enxofre (17%) apresentaram maior produção de grãos do cafeeiro
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