3,405 research outputs found

    Amino acids and biogenic amines evolution during the estufagem of fortified wines

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    The current study was focused on the impact of accelerated ageing (heating step) on the amino acid and biogenic amine profiles of fortified wines. In this sense, three Madeira wines from two commonly used grape varieties (one red and the other white) were analysed during the heating, at standard (45∘ C, 3 months) and overheating (70∘ C, 1 month) conditions, following a precolumn derivatization procedure using iodoacetic acid, o-phthaldialdehyde, and 2-mercaptoethanol, carried out in the injection loop prior to RP-HPLC-FLD detection. Eighteen amino acids were identified, with arginine being the most abundant. An important decrease of the amino acid levels was detected during the standard heating (up to 30%), enhanced up to 61% by the temperature increase. Cysteine, histidine, and asparagine revealed the greatest decreases at 45∘ C. Conversely, some amino acids, such as asparagine, slightly increased. Four biogenic amines were identified but always in trace amounts. Finally, it was observed that the accelerated ageing did not favour the biogenic amine development. The results also indicate that the heating process promotes the amino acid transformation into new ageing products.info:eu-repo/semantics/publishedVersio

    Wear and high temperature wear on MCrAlY HVOF coatings

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    Wear and high temperature wear involve mechanical and chemical mechanisms and the combination of these often result in significant wear and damage on metallic components. Thermal barrier coatings with MCrAlY alloy can improve the tribological and friction wear behaviour. One of the techniques for applying Thermal barrier coatings is thermal sprayed and specially the High velocity Oxi-Fuel (HVOF) is one of the most employed techniques for materials as Nickel or Cobalt base alloys. In this investigation tribological behaviour, on a dry friction and wear behaviour at room temperature and high temperature of new developed NiCoCrAlY and CoNiCrAlY, has been perform in order to know the impact of the technique applied on the coating. Tribological wear tests were performed by sliding wear at 20, 350 and 500 ºC, with an Al2O3 ball as pin on disk configuration tribometer. Wear test for NiCoCrAlY specimens has shown smaller weight losses and lower friction coefficient under high temperature, meanwhile CoNiCrAlY coating shows a unexpected ware rate at room temperature. The main damage mode for CoNiCrAlY coating at room temperature is abrasion, caused by particles detachment from coatings. The coatings and stainless steel substrate results were compared.The authors wish acknowledge the Institute of Technology of Materials where the test were performed

    Protocyon troglodytes (Lund) ( Mammalia, Carnivora ) in the late Pleistocene of Rio Grande do Sul and their paleoecological significance

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    An incomplete maxilla with P4 and M1, from the late Pleistocene lacustrine sands of the System Barrier III (Santa Vitória Formation), is the first record of Protocyon troglodytes (Lund) for the State of Rio Grande do Sul, Brazil. This material differs from Theriodictis, a closely related genus, in characters of the P4 (protocone more reduced) and M1 (hypocone more reduced, and the inner half mesiodistally narrower and straighter). Differently of southern Brazil living canids such as Chrysocyon brachyurus, Cerdocyon thous and Dusicyon gymnocercus, P. troglodytes developed dental adaptations associated to hypercarnivory in having large paracone on M1, strong reduction of protocone on P4 and reduction and simplification of talonids. In the latest Pleistocene, the climate was colder and grassland landscapes were predominant in southern Brazil, where several potential large and medium-sized ungulate preys were present. Protocyon troglodytes probably preyed on medium-sized grazers or browsers but not on the megafauna, or only on young individuals of this size class.Um maxilar incompleto com P4 e M1, coletado em sedimentitos lacustres do Pleistoceno Tardio do Sistema-Barreira III (Formação Santa Vitória), constitui o primeiro registro de Protocyon troglodytes (Lund) para o Rio Grande do Sul. Este material difere de Theriodictis, gênero intimamente relacionado a Protocyon, em caracteres do P4 (protocone reduzido) e do M1 (hipocone mais reduzido e apresentando sua porção lingual comprimida e retilínea). Diferentemente de canídeos sul-brasileiros atuais como Chrysocyon brachyurus, Cerdocyon thous e Dusicyon gymnocercus, P. troglodytes desenvolveu adaptações dentárias relacionadas à hipercarnivoria, em tendo um grande paracone no M1, forte redução do protocone no P4 e redução e simplificação de talonidos. No final do Pleistoceno o clima foi mais frio e mais seco no sul do Brasil, prevalecendo áreas abertas, onde várias presas potenciais compostas de ungulados de tamanho grande e médio estiveram presentes. Protocyon troglodytes, provavelmente, não predava megamíferos e sim herbívoros de tamanho médio ou apenas indivíduos jovens da megafauna.Fil: Oliveira, Édison V.. Universidade Federal do Rio Grande do Sul; BrasilFil: Prevosti, Francisco Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; ArgentinaFil: Pereira, Jamil C.. Museu Municipal de Santa Vitória do Palmar; Brasi

    A Fuzzy Syllogistic Reasoning Schema for Generalized Quantifiers

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    In this paper, a new approximate syllogistic reasoning schema is described that expands some of the approaches expounded in the literature into two ways: (i) a number of different types of quantifiers (logical, absolute, proportional, comparative and exception) taken from Theory of Generalized Quantifiers and similarity quantifiers, taken from statistics, are considered and (ii) any number of premises can be taken into account within the reasoning process. Furthermore, a systematic reasoning procedure to solve the syllogism is also proposed, interpreting it as an equivalent mathematical optimization problem, where the premises constitute the constraints of the searching space for the quantifier in the conclusion.Comment: 22 pages, 6 figures, journal pape

    Outcome measures and motion capture systems for assessing lower limb orthosis-based interventions after stroke: a systematic review

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    Purpose: To review and categorize, according to the International Classification of Functioning, the outcome measures, and motion capture systems for studying the evidence-based practice of orthotic-based interventions in post-stroke gait rehabilitation. Methods: An electronic literature search was conducted up to February 2018 in Web of Science, Scopus, MEDLINE and Physiotherapy Evidence Database. Randomized trials measuring activity, impairment or participation outcome measures for studying the evidence-based practice of orthoses in gait rehabilitation after an acute or chronic stroke were identified. The studies were assessed through the Cochrane risk-of-bias tool by three authors. Information about stroke’s stage, assessment protocol (goal, timing and motion capture system), orthosis configuration and outcome measures were extracted. Results: Eighteen randomized trials, including 387 post-stroke adults, mostly in the chronic stage, were selected. They assessed 39 outcomes, mainly activity outcome measures such as spatiotemporal (72.2%), kinematic (44.4%) and functional (33.3%) outcomes. Gait speed was the primary outcome in most studies. Participation (22.2%) and impairment (16.7%) outcome measures were less explored. Mostly, non-portable motion capture systems were employed opposing the freely-use of the wearable orthosis. The detection bias risk and the shortage of baseline and follow-up outcome measures affected the studies’ assessment quality. Conclusions: Studies showed heterogeneity in selecting outcomes and timings for assessment. There is evidence for assessing the evidence of orthosis-based gait rehabilitation after stroke through activity outcome measures, primarily the gait speed, recorded by non-wearable motion capture systems. A unified methodology considering wearable sensors for tracking baseline and follow-up measures is needed.Implications for rehabilitation There is evidence on use activity outcome measures to assess the meaningful evidence-based practice of orthosis-based gait rehabilitatio- (undefined

    HPLC-DAD methodology for the quantification of organic acids, furans and polyphenols by direct injection of wine samples

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    This article proposes a simple and sensitive HPLC method with photo-diode array detection for the analysis of organic acids, monomeric polyphenols and furanic compounds in wine samples by direct injection. The chromatographic separation of 8 organic acids, 2 furans and 22 phenolic compounds was carried out with a buffered solution (pH 2.70) and acetonitrile as mobile phases and a difunctionally bonded C18 stationary phase, Atlantis dC18 (250 4.6 mm, 5mm) column. The elution was performed in 12 min for the organic acids and in 60 min for the phenolic compounds, including phenolic acids, stilbenes and flavonoids. Target compounds were detected at 210 nm (organic acids, flavan-3-ols and benzoic acids), 254 nm (ellagic acid), 280 nm (furans and cinnamic acid), 315 nm (hydroxycinnamic acids and trans-resveratrol) and 360 nm (flavonoids). The RSD for the repeatability test (n55) of peak area and retention times were below 3.1 and 0.3%, respectively, for phenolics and below 1.0 and 0.2% for organic acids. The RSDs expressing the reproducibility of the method were higher than for the repeatability results but all below 9.0%. Method accuracy was evaluated by the recovery results, with averaged values between 80 and 104% for polyphenols and 97–105% for organic acids. The calibration curves, obtained by triplicate injection of standard solutions, showed good linearity with regression coefficients higher than 0.9982 for polyphenols and 0.9997 for organic acids. The LOD was in the range of 0.07–0.49 mg/L for polyphenols (cinnamic and gallic acids, respectively) and 0.001–0.046 g/L for organic acids (oxalic and lactic acids, respectively). The method was successfully used to measure and assess the polyphenolic fingerprint and organic acids profile of red, white, rose ´ and fortified wines

    Influencia de la formulación de espumas en medios porosos para procesos de recuperación mejorada de hidrocarburos

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    Los sistemas surfactantes presentan un alto interés en la industria petrolera por sus múltiples aplicaciones tecnológicas, en especial en los procesos de recuperación mejorada de hidrocarburos en los yacimientos. En el presente trabajo se desarrollaron sistemas unidimensionales micro porosos heterogéneos para medir la influencia de la inyección de espuma, empleando tres surfactantes a diferentes concentraciones (0,1; 1,0; 5,0; 10,0 % m/v). La mayor eficiencia de desplazamiento y recuperación se alcanzó con el surfactante SDS a la concentración de 5,0 %, al obtener un 70 % de rendimiento en extracción, en comparación con las demás concentraciones evaluadas. Este resultado demostró su aplicabilidad en el desarrollo de tecnologías nacionales para la recuperación mejorada en base a la inyección de espumas

    A sustainable production of natural hydraulic lime mortars through bio-amendment

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    .This article examined the effect of a bioproduct suspension obtained from fermentation of biodiesel’s crude glycerol when used to formulate natural hydraulic lime mortars, as a fluid replacing the mixing water. The bioproduct was used either sonicated or non-sonicated and two volumes of mixing fluid were tested. The aim was to assess the advantages and drawbacks that could be achieved with a waste-based bioproduct, instead of petrochemical-based additions. The investigation revealed a positive effect on workability, producing mortars with a lower mixing fluid content, improving the mechanical performance. Finally, the bioproducts reduced the mortar water absorption by gravity and capillary.S

    A comparative study of boron transport models in NRC thermal-hydraulic code TRACE

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    [EN] Recently, the interest in the study of various types of transients involving changes in the boron concentration inside the reactor, has led to an increase in the interest of developing and studying new models and tools that allow a correct study of boron transport. Therefore, a significant variety of different boron transport models and spatial difference schemes are available in the thermal-hydraulic codes. According to this interest, in this work it will be compared the results obtained using the different boron transport models implemented in the NRC thermal-hydraulic code TRACE. To do this, a set of models has been created using the different options and configurations that could have influence in boron transport. These models allow us to reproduce a simple event of filling or emptying the boron concentration in a long pipe. Moreover, with the aim to compare the differences obtained when one-dimensional or three-dimensional components are chosen, it has modeled many different cases using only pipe components or a mix of pipe and vessel components. In addition, the influence of the void fraction in the boron transport has been studied and compared under close conditions to a BWR commercial model. A final collection of the different cases and boron transport models are compared between them and those corresponding to the analytical solution provided by the Burgers equation. From this comparison, important conclusions are drawn that will be the basis of modeling the boron transport in TRACE adequately.Olmo-Juan, N.; Barrachina Celda, TM.; Miró Herrero, R.; Verdú Martín, GJ.; Pereira, C. (2019). A comparative study of boron transport models in NRC thermal-hydraulic code TRACE. Brazilian Journal of Radiation Sciences. 7(2B):1-18. https://doi.org/10.15392/bjrs.v7i2B.767S11872
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