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Chemical Composition,Antioxidant and Antimicrobial Activity of the Oil and Plant Extract Myrocarpus frondosus Allemao

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American Journal of Plant sciences 2017年第7期8卷 1560-1571页

作者： Ivandra Ignês de Santi Darci Alberto Gatto Miriam Ribeiro Galvao Machado Patrícia Soares Bilhalva dos Santos Rogerio Ant?nio Freitag Natural Products Research Laboratory Graduate Program in Biochemistry and Bioprospecting Federal University of Pelotas Pelotas Brasil Postgraduate Program Materials Science and Engineering Federal University of Pelotas Pelotas Brasil Center for Chemical Sciences Pharmaceutical and Food Federal University of Pelotas Pelotas Brasil Chemical and Environmental Engineering Department University of the Basque Country (UPV/EHU) San Sebastian Spain

The objective of this study was to evaluate the chemical profile of extracts (aqueous and ethanol) and the essential oil of Myrocarpus frondosus Allem?o, the sensitivity of strains of Escherichia coli, Staphylococcus aureus, Salmonella typhimurium and Listéria monocytogenes, front the extracts and essential oil, by means of the microdilution method in broth, the antioxidant activity by the ABTS method, and the content of phenolic compounds present in the extracts and oil. For the preparation of extracts from plant leaves used with ethanol and water, then separated, the chemical identification of compounds was performed by high-performance liquid chromatography (CLAE-DAD) and gas chromatography coupled to mass spectrum (CG/MS). With the chemical analysis of the extracts obtained the presence of the major compound rutin, and oil major compound was found germacrene B. In the microdilution method in broth, oil and extracts showed inhibition against all the bacteria tested in the concentrations 1 mg/ml to 0.25 mg/ml, except for Staphylococcus aureus at a concentration of 0.25 mg/ml of the essential oil and trans-caryophyllene. The results of Minimum Bactericidal Concentration showed that the essential oil had bactericidal activity at a concentration of 1mg/ml for all bacteria tested and trans-caryophyllene at the same concentration only for Listeria monocytogenes. In relation to the essential oil, antioxidant activity showed higher radical reduction capacity of 40.92% and the content of phenolic compounds ethanol extract showed more 12.72%. The in vitro results support the conclusion that the essential oil is very promising both in antimicrobial action as antioxidant activity and the leaf extracts on antioxidant activity.

关键词： Myrocarpus frondosus Allemao Antimicrobial Antioxidant

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Phase and crystallite size analysis of (Ti1-xMox)C-(Ni,Cr) cermet obtained by mechanical alloying

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AIP Conference Proceedings 2018年第1期1945卷

作者： Suryana Muhammad Anis Azwar Manaf 1Materials Science Postgraduate Program Physics Department Universitas Indonesia Jl. Salemba Raya No.4 Jakarta 10430 Indonesia 2Department of Metallurgy and Materials Engineering Universitas Indonesia Depok 16424 Indonesia

In this paper, we report the phase and crystallite size analysis of (Ti1-xMox)C-(Ni,Cr) with x = 0-0.5 cermet obtained by mechanical alloying of Ti, Mo, Ni, Cr and C elemental powders using a high-energy shaker ball mill under wet condition for 10 hours. The process used toluene as process control agent and the ball to mass ratio was 10:1. The mechanically milled powder was then consolidated and subsequently heated at a temperature 850°C for 2 hours under an argon flow to prevent oxidation. The product was characterized by X-ray diffraction (XRD) and scanning electron microscope equipped with energy dispersive analyzer. Results shown that, by the selection of appropriate condition during the mechanical alloying process, a metastable Ti-Ni-Cr-C powders could be obtained. The powder then allowed the in situ synthesis of TiC-(Ni,Cr) cermet which took place during exposure time at a high temperature that applied in reactive sintering step. Addition to molybdenum has caused shifting the TiC XRD peaks to a slightly higher angle which indicated that molybdenum dissolved in TiC phase. The crystallite size distribution of TiC is discussed in the report, which showing that the mean size decreased with the addition of molybdenum.

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Synthesis of green-emitting carbon quantum dots with excitation wavelength dependent photoluminescence obtained from aqueous beetroot extract

Synthesis of green-emitting carbon quantum dots with excitat...

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作者： Andrade, George R. S. Costa, Silvânio S. L. Nascimento, Cristiane C. Gimenez, Iara F. Postgraduate Program in Materials Science and Engineering Federal University of Sergipe Saõ Cristóvaõ Brazil Postgraduate Program in Chemistry Federal University of Bahia Salvador Brazil NUPEG Federal University of Sergipe Saõ Cristóvaõ Brazil Federal Institute of Education Science and Technology of Sergipe Aracaju Brazil Department of Chemistry Federal University of Sergipe Saõ Cristóvaõ Brazil

In this work, 3 simple, fast, labour and energy efficient methodologies were used to prepare carbon quantum dots (C-dots) using a red beetroot (Beta vulgaris subsp. vulgaris var. vulgaris) aqueous extract as the carbon source: Alkali-assisted (AA), microwave-assisted (MA) and alkali-microwave-assisted (AMA) synthesis. TEM images shows nanoparticles with a nearly spherical morphology and diameters around 7.0 nm. FTIR spectra show characteristic peaks of C-H, C-O, O-H and C=C bonds for all the samples. The emission spectra show an interesting feature of the as-prepared samples: The emission band position can be tunable by changing the excitation wavelength. Comparing the 3 different methodologies in terms of photoluminescence properties, the one based only on the microwave-assisted heating has showed the most improved emission. © 2016 materials Research Society.

关键词： Semiconductor quantum dots

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Upward and downward unsteady-state directional solidification of a hypoeutectic Al-3wt.%Mg alloy

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Ciencia e Tecnologia dos Materiais 2017年第1期29卷 e65-e70页

作者： Brito, C. Bertelli, F. Castanho, M.A.P. Goulart, P.R. Cheung, N. Spinelli, J.E. Garcia, A. Department of Marine Sciences Federal University of São Paulo UNIFESP SantosSP Brazil Department of Manufacturing and Materials Engineering University of Campinas UNICAMP CampinasSP Brazil Institute for Technological Research IPT São Paulo SP Brazil Federal Institute of Education Science and Technology of São Paulo IFSP Itapetininga SP Brazil Department of Materials Engineering Federal University of São Carlos UFSCar São CarlosSP Brazil Postgraduate Program of Mechanical Engineering Santa Cecília University UNISANTA SantosSP Brazil

Solidification thermal parameters, such as growth rate, cooling rate and dendrite arm spacing (λ), have been measured in a hypoeutectic Al-Mg alloy directionally solidified under upward and downward transient heat flow conditions. The experimental setup used in this work consists of a water-cooled mould with heat being extracted from the bottom or the top, promoting upward and downward directional solidification, respectively. It is shown that the dendritic arm spacing are not significantly affected by interdendritic convection for both solidification configurations and single growth laws are proposed for both cases. The Bouchard- Kirkaldy model is shown to overestimate the experimental primary dendritic arm spacing, despite fitting properly the secondary dendrite arm spacing. © 2017 Portuguese Society of materials (SPM)

关键词： Aluminum alloys

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S3M: A suggestion mechanism for semantic web service composition 15

S3M: A suggestion mechanism for semantic web service composi...

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21st Brazilian Symposium on Multimedia and the Web, WebMedia 2015

作者： Busanello Da Silva, Diogo P. Weber, Mathias Henrique Siqueira, Frank Department of Informatics and Statistics Federal University of Santa Catarina Florianópolis Brazil Postgraduate Program on Materials Science and Engineering Federal University of Santa Catarina Florianópolis Brazil

ISBN: (纸本)9781450339599

Web Service composition is a complex and error-prone process that requires the support of software tools in order to become feasible. Composition tools can help a developer to select compatible services from vast service repositories, taking into account characteristics such as port compatibility, availability, cost, and so on. This paper describes S3M, a service suggestion mechanism that, coupled with the CVFlow workflow editor, helps developers to select services and to build compositions. Service suggestions are given to the user taking into account the semantic description of Web Services in SAWSDL format. © 2015 ACM.

关键词： Websites

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Microwave-assisted hydrothermal synthesis of NiO-Ce1-xEuxO2-δ powders for fuel cell catalytic anodes

Microwave-assisted hydrothermal synthesis of NiO-Ce1-xEuxO2-...

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Symposium on Nanotechnology General Session - 225th ECS Meeting

作者： Medeiros, A.L. Martinelli, A.E. Melo, D.M.A. Orlandi, M.O. Macedo, D.A. Materials Science and Engineering Postgraduate Program UFRN Natal59072-970 Brazil Institute of Chemistry UNESP Araraquara14801-907 Brazil Department of Materials Engineering UFPB João Pessoa58051-900 Brazil

ISBN: (纸本)9781607685869

CeO2-based materials doped with rare earth (TR+3) can be used as alternative to traditional NiO-YSZ anodes in solid oxide fuel cells as they have higher ionic conductivity and lower ohmic losses compared to YSZ. Moreover, they allow fuel cell operation at lower temperatures (500-800°C). In the anode composition, the concentration of NiO acting as catalyst in YSZ provides high electrical conductivity and high electrochemical activity of reactions, promoting internal reform in the cell. In this work, NiO - Ce1-xEuxO2-δ compounds (x = 0.1, 0.2 and 0.3) have been synthesized by microwave-assisted hydrothermal method. The materials were characterized by TG, XRD, TPR and SEM-FEG techniques. The refinement of data obtained by X-ray diffraction showed the presence of ceria doped with europium crystallized in a cubic phase with fluorite structure, in addition to the presence of NiO. The microwaveassisted hydrothermal method showed significant reduction in the average particle size and good mass control of phase compositions compared to other chemical synthesis techniques. © The Electrochemical Society.

关键词： Nickel oxide

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Electrical properties of lanthanum silicate apatite electrolytes prepared by an innovative chemical route

Electrical properties of lanthanum silicate apatite electrol...

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Symposium on Nanotechnology General Session - 225th ECS Meeting

作者： Macedo, G.L.S. Macedo, D.A. Rajesh, S. Martinelli, A.E. Figueiredo, F.M.L. Marques, F.M.B. Nascimento, R.M. Department of Chemical Engineering UFRN Natal59078-970 Brazil Department of Materials Engineering UFPB João Pessoa58051-900 Brazil Dept. of Materials and Ceramic Eng. CICECO University of Aveiro 3810-193 Portugal Materials Science and Engineering Postgraduate Program UFRN 59078-970 Brazil

ISBN: (纸本)9781607685869

This work reports the synthesis of apatite-type lanthanum silicate powders with nominal composition La10Si6O27 by an innovative chemical route which combines co-precipitation and sol-gel approaches. The herein proposed synthetic procedure is advantageous in reducing energy consumption and processing time, key elements to decrease the total manufacturing cost. The asprepared powder was calcined between 500 and 900 °C. Structure of the calcined powders, characterized by X-ray diffraction (XRD) and Rietveld refinement, indicated the formation of apatite crystalline lanthanum silicate with minor amount of L2O3 at 900 °C. The apatite powder was further analyzed by scanning electron microscopy (SEM). The effect of sintering temperature, ranging from 1400 to 1450 °C, on the electrical properties was investigated by impedance spectroscopy. Electrical measurements were recorded in the 400-800 °C temperature range. The lanthanum silicate electrolyte sintered at 1450 °C exhibited total electrical conductivity (σ700 °C = 2.12 × 10-3 ***-1) comparable with samples from literature prepared by sol-gel and freeze drying methods and sintered at 1500 °C. The results in the present study demonstrate that the co-precipitation method combined with a solgel approach is a promising alternative route to synthesize lanthanum silicate powders. © The Electrochemical Society.

关键词： Powders

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A flexible ultrasonic velocity profiler development environment

A flexible ultrasonic velocity profiler development environm...

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IEEE Instrumentation and Measurement Technology Conference

作者： César Yutaka Ofuchi Fabio Rizental Coutinho Raquel dos Santos Rasia Lucia Valeria Ramos de Arruda Flávio Neves Rigoberto Eleazar Melgarejo Morales Graduate School of Electrical Engineering and Computer Science (CPGEI) Federal University of Technology-Paraná (UTFPR) Curitiba Brazil Mechanical & Materials Engineering Postgraduate Program (PPGEM) Federal University of Technology-Paraná (UTFPR) Curitiba Brazil

ISBN: (纸本)9781467363846

Ultrasonic velocity profiler method is now an accepted tool in modern experimental fluid mechanics and fluid engineering. As a relative new technology, different applications and improvements of the technique are being researched over the last years. This paper presents an environment to develop new algorithms to improve the ultrasonic velocity estimation technique. The system uses the LabVIEW modular platform integrated with mathematical script language used in many signal-processing software. The phase-shift algorithm was implemented and tested using the proposed system. The results are validated with standard velocity measurements generated by a rotating cylinder.

关键词： Acoustics Velocity measurement Software Signal processing algorithms Ultrasonic variables measurement Fluids Doppler effect

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Microstructure and wear resistance of spray-formed supermartensitic stainless steel

Microstructure and wear resistance of spray-formed supermart...

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作者： Zepon, Guilherme Kiminami, Claudio Shyinti Filho, Walter José Botta Bolfarini, Claudemiro Postgraduate Program in Science and Materials Engineering Federal University of São Carlos - UFSCar São Carlos SP Brazil Department of Materials Engineering Federal University of São Carlos - UFSCar São Carlos SP Brazil

Since the early 90's the oil industry has been encouraging the development of corrosion and wear resistant alloys for onshore and offshore pipeline applications. In this context supermartensitic stainless steel was introduced to replace the more expensive duplex stainless steel for tubing applications. Despite the outstanding corrosion resistance of stainless steels, their wear resistance is of concern. Some authors reported obtaining material processed by spray forming, such as ferritic stainless steel, superduplex stainless steel modified with boron, and iron-based amorphous alloys, which presented high wear resistance while maintaining the corrosion performance. The addition of boron to iron-based alloys promotes the formation of hard boride particles (M2B type) which improve their wear resistances. This work aimed to study the microstructure and wear resistance of supermartensitic stainless steel modified with 0.3 wt. (%) and 0.7 wt. (%) processed by spray forming (SF-SMSS 0.3%B and SF-SMSS 0.7%B, respectively). These boron contents were selected in order to improve the wear resistance of supermartensitic stainless steel through the formation of uniformly distributed borides maintaining the characteristics of the corrosion resistant matrix. SF-SMSS 0.7%B presents an abrasive wear resistance considerably higher than spray-formed supermartensitic stainless steel without boron addition (SF-SMSS). © 2013.

关键词： Wear resistance

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Thermoeconomic design and optimization of frost-free refrigerators

Thermoeconomic design and optimization of frost-free refrige...

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作者： Mitishita, Rodrigo S. Barreira, Eduardo M. Negrão, Cezar O.R. Hermes, Christian J.L. Thermal Science Laboratory Postgraduate Program of Mechanical and Materials Engineering Federal University of Technology - Paraná Av. Sete de Setembro 3165 80230901 Curitiba PR Brazil Center for Applied Thermodynamics Department of Mechanical Engineering Federal University of Paraná P.O. Box 19011 81531990 Curitiba PR Brazil

An optimization methodology aiming at energy and cost savings in frost-free refrigerators is advanced. A steady-state simulation model was devised and its predictions for energy consumption were compared with experimental data obtained elsewhere, with differences not exceeding a +/- 9% error band. The model was used to find out the evaporator air flow rate, the number of evaporator and condenser fins, the compressor size and efficiency, and the insulation thicknesses of both fresh- and frozen-food compartments which yield the minimum energy consumption when the total cost is constrained. The optimization led to a refrigeration system with energy consumption 18% lower than that observed for the baseline system without any cost penalty. The system performance for four different compressors, including a high efficiency, a large capacity and a variable-speed one, was also analyzed. For the refrigerator under analysis, it was found that, to ensure an economically feasible design, the variable-speed compressor should not cost 26% more than a single-speed one with the same piston displacement. © 2012 Elsevier Ltd. All rights reserved.

关键词： Compressors

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