947 research outputs found

    Componentes minoritarios de aceites obtenidos de frutos de palmeras de la región amazónica

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    This study deals with the characterization of minor compounds in oils obtained from the mesocarp of fruits of the main palm species from the State of Amapá, Brazil, i.e. bacaba (Oenocarpus bacaba), buriti (Mauritia flexuosa), inajá (Maximiliana maripa), pupunha (Bactris gasipaes) and tucumã (Astrocaryum vulgare). The concentration of minor glyceridic compounds, i.e. dimeric triacylglycerols (TAG), the oxidized TAG and diacylglycerols (DAG) related to oil quality, and the compounds of unsaponifiable matter, i.e. hydrocarbons, aliphatic alcohols, sterols and tocopherols have been determined. The results indicate that the extracted oils had good initial quality, with DAG as the major glyceridic compound. The contents of hydrocarbons (50-734 mg·kg–1) and aliphatic alcohols (80-490 mg·kg–1) were highly variable with inajá oil containing the highest contents. In the case of tocopherols, buriti (1567 mg·kg–1) and tucumã (483 mg·kg–1) oils had the highest contents and the presence of significant amounts of tocotrienols was only detected in inajá oil. Finally, high concentrations of sterols were found in all the samples, particularly in the oils from pupunha (4456 mg·kg–1) and tucumã (2708 mg·kg–1), with β-sitosterol being the major sterol in all the samples with percentages between 65 and 83%.El objetivo de este estudio fue la caracterización de los componentes menores presentes en los aceites obtenidos del mesocarpio de frutos de especies de bacaba (Oenocarpus bacaba), buriti (Mauritia flexuosa), inajá (Maximiliana maripa), pupuña (Bactris gasipaes) y tucumá (Astrocaryum vulgare), de importante producción en el Estado de Amapá, Brasil. Se determinaron las dos principales fracciones presentes en los aceites. Por una parte, los compuestos menores derivados de los componentes mayoritarios o triglicéridos (TAG): dímeros de TAG, TAG oxidados y diglicéridos (DAG) relacionados con la calidad de los aceites y, por otra, los principales grupos presentes en la fracción insaponificable (hidrocarburos, alcoholes alifáticos, esteroles y tocoferoles) relacionados con la calidad de los aceites. Los resultados indicaron que todos los aceites extraídos tenían buena calidad inicial, siendo los DAG los mayoritarios entre los compuestos menores glicerídicos. La concentración de hidrocarburos (50-734 mg·kg–1) y de alcoholes alifáticos (80-490 mg·kg–1) fue muy variable correspondiendo al aceite de inajá el mayor contenido en hidrocarburos y en alcoholes. En el caso de los tocoferoles, las mayores cantidades correspondieron a los aceites de buriti (1567 mg·kg–1) y tucumá (483 mg·kg–1) y la presencia de cantidades significativas de tocotrienoles sólo se detectaron en aceite de inajá. Finalmente, se encontraron concentraciones elevadas de esteroles en todas las muestras, especialmente en los aceites de pupuña (4456 mg·kg–1) y tucumá (2708 mg·kg–1), siendo el β-sitosterol el esterol mayoritario con porcentajes entre 65 y 83%

    Magnetic And Magnetocaloric Properties On The U1-y Ry Ga2 (r=er And Dy) Compound

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    The magnetic, calorimetric, and magnetocaloric properties of the pseudobinary U1-y Ry Ga2 (R=Er and Dy) series were studied to determine its potential as a candidate for use in cryogenic magnetic refrigeration. The partial substitution of Dy and Er for U provides a wide range of the ordering temperature and increases the saturation magnetic moment. The results for U1-y Dyy Ga2 with 0.6<y<0.9 show evidences of a spin-glass-like (SG) behavior, possibly as a consequence of competing anisotropy and exchange interactions within a frustrated hexagonal spin lattice. The isothermal magnetic entropy change (Δ Smag) observed for U Ga2 shows a well defined peak centered on TC, which is gradually broadened and shifted to lower temperatures as the Er and Dy content increases. For low concentrations (0.2≤y≤0.4) a tablelike profile is observed in the Δ Smag curve. © 2008 American Institute of Physics.1037Gschneidner Jr., K.A., Pecharsky, V.K., Tsokol, A.O., (2005) Radiat. Prot. Dosim., 68, p. 1479Bruck, E., (2005) J. Phys. D, 38, p. 381Yu, B.F., Gao, Q., Zhang, B., Meng, X.Z., Chen, Z., (2003) Int. J. Refrig., 26, p. 622Gschneidner Jr., K.A., Pecharsky, A.O., Pecharsky, V.K., (2001), 11, p. 433. , Cryoolers (Academic-Plenum, New York), Vol.,Smaili, A., Chahine, R., (1996) Adv. Cryog. Eng., 42, p. 445Hashimoto, T., Kuzuhura, T., Sahashi, M., Inomata, K., Tomokiyo, A., Yayama, H., (1987) J. Appl. Phys., 62, p. 3873Lima, A.L., Gschneidner Jr., K.A., Pecharsky, V.K., Pecharsky, A.O., (2003) Phys. Rev. B, 68, p. 134409De Oliveira, N.A., Von Ranke, P.J., (2003) J. Magn. Magn. Mater., 264, p. 55Tsai, T.H., Sellmyer, D.J., (1979) Phys. Rev. B, 20, p. 4577Doukouŕ, M., Gignoux, D., (1982) J. Magn. Magn. Mater., 30, p. 111Gignoux, D., Schimitt, D., Takeuchi, A., Zhang, F.Y., (1991) J. Magn. Magn. Mater., 97, p. 15Andreev, A.V., Belov, K.P., Deryagin, A.V., Levitin, R.Z., Menovsky, M., (1979) J. Phys. Colloq., 4, p. 82Mydosh, J.A., (1993), Spin Glasses: An Experimental Introduction (Taylor&Francis, London)Markin, P.E., Baranov, N.V., Sinitsyn, E.V., (1991) Physica B, 168, p. 19

    Cognitive performance of young and elderly subjects on the free word recall memory test: effect of presentation order on recall order

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    The influence of aging on memory has been extensively studied, but the importance of short-term memory and recall sequence has not. The objective of the current study was to examine the recall order of words presented on lists and to determine if age affects recall sequence. Physically and psychologically healthy male subjects were divided into two groups according to age, i.e., 23 young subjects (20 to 30 years) and 50 elderly subjects (60 to 70 years) submitted to the Wechsler Adult Intelligence Scale-Revised and the free word recall test. The order of word presentation significantly affected the 3rd and 4th words recalled (P < 0.01; F = 14.6). In addition, there was interaction between the presentation order and the type of list presented (P < 0.05; F = 9.7). Also, both groups recalled the last words presented from each list (words 13-15) significantly more times 3rd and 4th than words presented in all remaining positions (P < 0.01). The order of word presentation also significantly affected the 5th and 6th words recalled (P = 0.05; F = 7.5) and there was a significant interaction between the order of presentation and the type of list presented (P < 0.01; F = 20.8). The more developed the cognitive functions, resulting mainly from formal education, the greater the cognitive reserve, helping to minimize the effects of aging on the long-term memory (episodic declarative).Associação Fundo de Incentivo à Psicofarmacologia Instituto do SonoUniversidade Federal de São Paulo (UNIFESP) Departamento de PsicobiologiaUNIFESP, Depto. de PsicobiologiaSciEL

    Characterisation of electrical power systems based on electrical curves and their properties

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    [Abstract]: Due to the proliferation of renewable energy systems, the study of voltage and frequency stability is a crucial aspect. Recently, this problem has been approached from a purely geometrical point of view with interesting results. The present work investigates the properties of the so-called electrical curves described by arbitrary voltage or current vectors in Euclidean spaces. Through the invariants of these curves, certain indices can be constructed to detect abnormal operation or irregular characteristics in electrical power systems. Different scenarios and examples have been solved in this work to support the proposed theory

    DSUALMH-A new high-resolution dataset for NILM

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    [Abstract]: The optimisation of energy consumption requires a reasonably accurate measurement, so an appropriate and advanced monitoring system of the relevant electrical variables in the electrical installations is of paramount importance. In this context, interoperable and highly configurable devices play a crucial role. A clear example is the OpenZMeter (OZM) which is an open source, open hardware, multi-purpose precision smart meter that can measure a wide range of electrical variables at a high sampling rate and provide processed data on power quality. The aim of this work is to show the use and possible applications of the new high sampling frequency data provided by the OZM device, which are much richer and more accurate than those obtained with other low-cost electrical meters. For this purpose, the opensource tool NILMTK has been used and adapted. Likewise, the use of two of the best known and most widely used algorithms such as Combinatorial Optimisation (CO) and the Factorial Hidden Markov Model (FHMM) has been considered, analysing the results obtained in the experimental study and offering a detailed comparison of the performance of the two different disaggregation algorithms using metrics for the different cases, as well as the incorporation of transients, and the comparison with other public DatasetsMinisterio de Ciencia, Innovación y Universidades; PGC2018-098813-B-C33Universidad de Almería; UAL2020-TIC-A208

    A tool to select offshore renewable energy facilities. The case of study of shipyards and ports in Spain

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    [Abstract]: The objective of this work is to create a tool that serves to know the possibilities of manufacturing, storage, assembly, and maintenance of floating marine structures trying to take advantage of the ports and shipyards of Spain. This would help reduce costs and could make this type of energy more profitable. To this end, all the Spanish ports and shipyards have been analyzed, considering the characteristics and possibilities of each of them. In the study, those that did not meet certain essential conditions for the manufacture, storage, assembly, and maintenance of power generation equipment have been discarded.Ministerio de Ciencia e Investigación; /10.13039/50110001103

    Magnetization And Specific Heat In U 1-xla Xga 2 And Magnetocaloric Effect In Uga 2

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    We have investigated the properties of the ferromagnetic series U1-x Lax Ga2. The magnetization results show a reduction of μeff and of Tc when x is increased. The electronic coefficient γ of the specific heat increases to a maximum of 260 mJUmol K2 at x=0.75. This behavior is probably consequence of delocalization of 5f electrons, causing enhancement of the density of states. For x=0.9 the ordering disappears and a non-Fermi-liquid behavior is observed. U Ga2 also presented a significant magnetocaloric effect of Δ Smag =-3.5 Jkg K at 120 K and H=7 T which can be modified by chemical pressure. © 2005 American Institute of Physics.9710Andeev, A.V., Belov, K.P., Deriagin, A.V., Levitin, R.Z., Menovsky, A., (1979) J. Phys. Colloq., 4, p. 82Da Silva, L.M., Gandra, F.G., Rojas, D.P., Cardoso, L.P., Medina, A.N., (2002) Physica B, 312-313, p. 906Tran, V.H., Kaczorowski, D., Roisnel, T., Tróc, R., Noel, H., Bouŕe, F., Andŕ, G., (1995) Physica B, 205, p. 24Gandra, F.G., Rojas, D.P., Shlyk, L., Cardoso, L.P., Medina, A.N., (2001) J. Magn. Magn. Mater., 226, p. 1312Barbara, B., (1973) J. Phys. (Paris), 34, p. 1039Sechovsky, V., Havela, L., Svoboda, P., (1986) J. Less-Common Met., 121, p. 163Segal, E., Wallace, W.E., (1975) J. Solid State Chem., 13, p. 201Radwanski, R.J., Kim-Ngan, N.H., (1995) J. Magn. Magn. Mater., 140, p. 1373Zapf, V.S., Dickey, R.P., Freeman, E.J., Sirvent, C., Maple, M.B., (2002) Phys. Rev. B, 65, p. 024437Pecharsky, V.K., Gschneider Jr., K.A., (1997) Phys. Rev. Lett., 78, p. 4494Pecharsky, V.K., Gschneider Jr., K.A., (1997) Phys. Rev. Lett., 78, p. 4494Plackowski, T., Junod, A., Bouquet, F., Sheikin, I., Wang, Y., Jezÿowski, A., Mattenberger, K., (2003) Phys. Rev. B, 67, p. 184406Svobodaa, P., Sechovsky, V., Menovsky, A.A., (2003) Physica B, 339, p. 177Gama, S., Coelho, A.A., De Campos, A., Carvalho, A.M.G., Gandra, F.G., Von Ranke, P.J., De Oliveira, N.A., Phys. Rev. Lett

    Modelos acoplados do IPCC-AR4 e o gradiente meridional de temperatua da superficie do mar no atlântico tropical : relaçoes com a precipitaçao no norte do nordeste do Brasil

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    Este artigo mostra como três modelos acoplados do Intergovernmental on Panel Climate Change - (IPCC-AR4), o FGOALS1. 0G &#8211; LASG do Institute of Atmospheric Physics of China, o GISSER da National Aeronautics Space Admnistration (NASA) e o GFDL_CM2 da National Oceanic and Atmospheric Administration (NOAA), simularam a variabilidade do gradiente meridional de Temperatura da Superfície do Mar (TSM), entre os meses de fevereiro a maio, no Atlântico Tropical (1901-1999). A precipitação durante a estação chuvosa (fevereiro a maio) no setor norte do Nordeste do Brasil (NEB) foi também analisada pelos três modelos e comparada com as observações. Os modelos GISSER e FGOALS1.0G mostraram melhor desempenho na simulação do sinal do gradiente meridional de TSM no Atlântico Tropical para o período de 1901 a 1999. Destaca-se que os modelos apresentaram um melhor desempenho na simulação da tendência decadal, conseguindo explicar entre 50% a 80% da variabilidade do gradiente, com a TSM do setor sul sendo mais bem simulada
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