8,735 research outputs found

    Farinha mista de triticale e trigo para produção de pães.

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    Foram avaliadas farinhas mistas de trigo e triticale, nas proporções 9:10, 80:20 e 70:30, quanto a composição química, propriedades reológicas e viscoamilográficas e comportamento em panificação. As temperaturas iniciais de gelatinização das três farinhas foram iguais (68oC), porém inferiores à farinha de trigo (70oC). A temperatura de viscosidade máxima, faixa de gelatinização e viscosidade máxima decresceu à medida que foram aumentados os níveis de substituição da farinha de trigo pela de triticale. A estabilidade da massa, o índice valorimétrico e o tempo de saída diminuiram a medida que a participação da farinha de triticale aumentou nas farinhas mistas, enquanto o índice de tolerância da mistura e queda após vinte minutos, aumentaram. A resistência à extensão, a força total e o número proporcional para as três farinhas mistas cresceram com o aumento de tempo de fermentação da massa enquanto a extensibilidade diminuiu. As avaliações das propriedades reológicas das massas iniciaram que para a produção de pães com essas farinhas foi necessário reduzir os tempos de mistura e de fermentação. Os pães produzidos com as farinhas 9:10 e 80:20 foram considerados muito bons e se igualaram ao padrão de trigo. Os volumes e volumes específicos dos pães obtidos a partir das farinha s mistas foram, para os três níveis de substituição, superiores àquele obtido com a farinha de trigo.bitstream/item/65352/1/CTAA-DOCUMENTOS-1.FARINHA-MISTA-DE-TRITICALE-E-TRIGO-PARA-PRODUCAO-DE-PAES-FL-06779-.pd

    Multivariate analysis of nonlinearity in sandbar behavior

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    International audienceAlongshore sandbars are often present in the nearshore zones of storm-dominated micro- to mesotidal coasts. Sandbar migration is the result of a large number of small-scale physical processes that are generated by the incoming waves and the interaction between the wave-generated processes and the morphology. The presence of nonlinearity in a sandbar system is an important factor determining its predictability. However, not all nonlinearities in the underlying system are equally expressed in the time-series of sandbar observations. Detecting the presence of nonlinearity in sandbar data is complicated by the dependence of sandbar migration on the external wave forcings. Here, a method for detecting nonlinearity in multivariate time-series data is introduced that can reveal the nonlinear nature of the dependencies between system state and forcing variables. First, this method is applied to four synthetic datasets to demonstrate its ability to qualify nonlinearity for all possible combinations of linear and nonlinear relations between two variables. Next, the method is applied to three sandbar datasets consisting of daily-observed cross-shore sandbar positions and hydrodynamic forcings, spanning between 5 and 9 years. Our analysis reveals the presence of nonlinearity in the time-series of sandbar and wave data, and the relative importance of nonlinearity for each variable. The relation between the results of each sandbar case and patterns in bar behavior are discussed, together with the effects of noise. The small effect of nonlinearity implies that long-term prediction of sandbar positions based on wave forcings might not require sophisticated nonlinear models

    Determining efficient places for grab bars in public toilets for disabled persons

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    Eine bemerkenswerte Bio- und Lithofazies an der Basis des Unter-Hauterivium Nordwestdeutschlands

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    Im östlichen Teil des Niedersächsischen Beckens ist das Trans gressionskonglomerat des Unter-Hauterivium-Meeres ("Hilskon- glomerat") in Küsten- und Schwellennähe durch einen hohen, meist organogenen Karbonatgehalt (Biosparit), Biomikrit, Kalk und Mergelstein) sowie Brauneisengeröll- und Quarzsandführung gekennzeichnet. Gleichzeitig weisen diese Basisschichten des Unter-Hauterivium hier einen außergewöhnlichen Fauneninhalt auf ("Sonderfazies”), der im küstenferneren Bereich des östlichen wie auch im Gesamtbereich des mittleren und westlichen Niedersächsischen Beckens bisher nicht beobachtet werden konnte ("Normalfazies"). In der Mikrofauna erscheinen, z.T. im Faunenbild dominierend, Foraminiferen mediterraner Herkunft (Trocholina, Meandrospira Cyclammina u.a.). Auch die Megafauna der "Sonderfazies" ist durch Warm- und Flachwasserformen (Kalkschwämme, Korallen, Bryozoen, Serpuliden, Seelilien) charakterisiert. Da auch in der östlichen Fortsetzung des Norddeutsch-Polnischen Unterkreide-Meeres (Brandenburg, Mecklenburg) u.a. eben falls die Foraminiferen-Gattungen Trocholina und Cyclammina sowie Bryozoen und Seelilien beobachtet werden konnten und im Hauterivium lediglich über die südpolnische Meeresstraße eine Verbindung zum mediterranen Meeresraum bestand, müssen warme Meeresströmungen aus südöstlicher Richtung als Ursache für den Karbonatreichtum der Sedimente und deren Besiedelung durch benthische "Warmwasserformen" angenommen werden. Auch die Ammoniten-Gattung Endemoceras ist nach Untersuchungen von THIERMANN (1963) auf diesem Wege in das Niedersächsische Becken eingewandert. Da die Unterkreide-Transgression mit Konglomerat- und Aufarbeitungshorizonten in einigen küsten- und schwellennahen Bereichen des nordwestdeutschen Unterkreide-Meeres bereits im höheren Valanginium oder aber erst im höheren Unter-Hauteri- vium (z.B. Fallsteingebiet) bzw. tiefem Ober-Hauterivium (z.B. Westerberg b. Alfeld) erfolgte, ist das sog. "Hilskon- glomerat" i.w.S. nicht als synchrone Bildung anzusehen. Allerdings konnten der spezifische petrographische Charakter sowie die typische Fauaenvergesellschaftung der "Sonderfazies" bisher nur im Basiskonglomerat des Unter-Hauterivium und nur im östlichen Teil des Niedersächsischen Beckens beobachtet werden. Daraus ließe sich ableiten, daß nur für einen (im geologischen Maßstab!) enger begrenzten Zeitraum (tieferes Unter- Hauterivium) die zur Entstehung der "Sonderfazies" notwendigen hydrologischen und klimatischen Voraussetzungen gegeben waren. So nimmt der Karbonatgehalt der Sedimente bis zum Unter-Aptium deutlich ab; nur im höheren Ober-Hauterivium steigen die Karbonatgehalte wieder stärker an, um dann im Barremium und Unter- Aptium die im Durchschnitt geringsten Werte der borealen Unterkreide NW-Deutschlands zu erreichen. Erst im Ober-Aptium steigen die Karbonatgehalte wieder an, sinken im Unter-Albium deutlich ab und nehmen vom Mittel-Albium bis Cenomanium kontinuierlich zu. Parallel zum abnehmenden Karbonatgehalt der Sedimente verschwinden bereits im Hauterivium Korallen, Kalkschwämme und Bryozoen, im höchsten Ober-Hauterivium auch die Crinoiden. Erst im höheren Unter-Albium erscheinen wieder Crinoiden im Faunenbild der Bodentier-Vergesellschaftungen. Daraus läßt sich eine deutliche Temperaturabnahme - zumindest im Bodenwasserbereich - infolge fehlender warmer Meeres-Strömungen, verbunden mit einer Zunahme der Wassertiefe im Beckenbereich vom Unter-Barremium bis Unter-Aptium, ableiten. Nach beträchtlicher regionaler Ausweitung der Meeresräume während des Albium kennzeichnen abseits der Küsten- und Schwellenbereiche erstmalig pelagische Faziesverhältnisse das lithologische und faunistische Bild der höheren Unterkreide NW-Deutschlands

    Direct Experimental Evidence for Differing Reactivity Alterations of Minerals following Irradiation: The Case of Calcite and Quartz

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    Concrete, a mixture formed by mixing cement, water, and fine and coarse mineral aggregates is used in the construction of nuclear power plants (NPPs), e.g., to construct the reactor cavity concrete that encases the reactor pressure vessel, etc. In such environments, concrete may be exposed to radiation (e.g., neutrons) emanating from the reactor core. Until recently, concrete has been assumed relatively immune to radiation exposure. Direct evidence acquired on Ar+^+-ion irradiated calcite and quartz indicates, on the contrary, that, such minerals, which constitute aggregates in concrete, may be significantly altered by irradiation. Specifically, while quartz undergoes disordering of its atomic structure resulting in a near complete lack of periodicity, i.e., similar to glassy silica, calcite only experiences random rotations, and distortions of its carbonate groups. As a result, irradiated quartz shows a reduction in density of around 15%, and an increase in chemical reactivity, described by its dissolution rate, similar to a glassy silica; i.e., an increase of around 3 orders of magnitude. Calcite however, shows little change in dissolution rates - although its density noted to reduce by around 9%. These differences are correlated with the nature of bonds in these minerals, i.e., being dominantly ionic or covalent, and the rigidity of the mineral's atomic network that is characterized by the number of topological constraints (nc_c) that are imposed on the atoms in the network. The outcomes are discussed within the context of the durability of concrete structural elements formed with calcitic/quartzitic aggregates in nuclear power plants

    Enhancing the Performance of Rapeseed Oil Lubricant for Machinery Component Applications through Hybrid Blends of Nanoadditives

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    Bio-lubricants have demonstrated promising tribological and physical properties, suggesting their potential advantages in the lubrication of critical machinery components. This study investigates the impact of using blended individual and hybrid nanoadditives, such as graphene nanoplatelets, ZnO, and an ionic liquid (IL) of Trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl)phosphinate, on the rheological, tribological, and physical characteristics of rapeseed oil. A commercial cutting fluid (BLASER Vasco 6000) (VB 6000) is used for comparison. The results revealed a substantial improvement in viscosity index (VI) values for mixtures containing graphene nanoplatelets, reaching up to 150%, as compared to VB 6000. Regarding the tribological behavior, the friction coefficient achieved a reduction of up to 20% at room temperature (RT) and 26% at 60 °C for the hybrid containing all three nanoadditives (H3), outperforming the commercial fluid. Moreover, H3 demonstrated the most substantial reductions in wear volume (84%) and surface roughness (60%). The wettability of H3 benefited from the combined mechanisms of the applied nanoadditives; its application the contact angle decreased by 63%, revealing its outstanding spreadability. The results reveal the high potential of the H3 hybrid as a competitive and green metal working fluid that can replace hostile and toxic ones in industrial applications

    Impact of copper and iron binding properties on the anticancer activity of 8-hydroxyquinoline derived Mannich bases.

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    The anticancer activity of 8-hydroxyquinolines relies on complex formation with redox active copper and iron ions. Here we employ UV-visible spectrophotometry and EPR spectroscopy to compare proton dissociation and complex formation processes of the reference compound 8-hydroxyquinoline (Q-1) and three related Mannich bases to reveal possible correlations with biological activity. The studied derivatives harbor a CH2-N moiety at position 7 linked to morpholine (Q-2), piperidine (Q-3), and chlorine and fluorobenzylamino (Q-4) substituents. Solid phase structures of Q-3, Q-4·HCl·H2O, [(Cu(HQ-2)2)2]·(CH3OH)2·Cl4·(H2O)2, [Cu(Q-3)2]·Cl2 and [Cu(HQ-4)2(CH3OH)]·ZnCl4·CH3OH were characterized by single-crystal X-ray diffraction analysis. In addition, the redox properties of the copper and iron complexes were studied by cyclic voltammetry, and the direct reaction with physiologically relevant reductants (glutathione and ascorbic acid) was monitored. In vitro cytotoxicity studies conducted with the human uterine sarcoma MES-SA/Dx5 cell line reveal the significant cytotoxicity of Q-2, Q-3, and Q-4 in the sub- to low micromolar range (IC50 values 0.2-3.3 μM). Correlation analysis of the anticancer activity and the metal binding properties of the compound series indicates that, at physiological pH, weaker copper(ii) and iron(iii) binding results in elevated toxicity (e.g.Q4: pCu = 13.0, pFe = 6.8, IC50 = 0.2 μM vs.Q1: pCu = 15.1, pFe = 13.0 IC50 = 2.5 μM). Although the studied 8-hydroxyquinolines preferentially bind copper(ii) over iron(iii), the cyclic voltammetry data revealed that the more cytotoxic ligands preferentially stabilize the lower oxidation state of the metal ions. A linear relationship between the pKa (OH) and IC50 values of the studied 8-hydroxyquinolines was found. In summary, we identify Q-4 as a potent and selective anticancer candidate with significant toxicity in drug resistant cells

    Energy-based modelling of adhesive wear in the mixed lubrication regime

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    Adhesive wear in dry contacts is often described using the Archard or Fleischer model. Both provide equations for the determination of a wear volume, taking the load, the sliding path and a set of material parameters into account. While the Fleischer model is based on energetic approaches, the Archard formulation uses an empirical factor-the wear coefficient-describing the intensity of wear. Today, a numerical determination of the wear coefficient is already possible and both approaches can be deduced to a local accumulation of friction energy. The aim of this work is to enhance existing energy-based wear models into the mixed lubrication regime. Therefore, the pressure distribution within the contact area will be determined numerically taking real surface topographies into account. The emerging contact area will be divided into one part of solid and a second part of elastohydrodynamically lubricated (EHL) contacts. Based on the resulting pressure and shear stress distribution, the formation of micro cracks within the loaded volume will be described. Determining a critical number of load cycles for each asperity, a locally resolved wear coefficient will be derived and the local wear depth calculated
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