815 research outputs found

    Granitos postcinemáticos de tendencia alcalina en Ossa Morena: el stock de la Cardenchosa (prov. de Córdoba)

    Get PDF
    El stock de La Cardenchosa forma part d'un grup de granits post-cinemàtics de tendència alcalina d'edat posttournaisiana i que afloren en la zona d'Ossa Morena. Aquests granits presenten com trets característics l'allargament N-S dels seus afloraments, el seu emplaçament superficial, la presència de fàcies leucocràtiques i l'íntima connexió dels jaciments de fluorita i/o barita. La composició química i menirelògica del stock de La Cardenchosa és comparada amb altres de la mateixa regió

    Pegmatitas en materiales metamórficos del norte de la provincia de Córdoba. Mineralogía y posibilidades económicas

    Get PDF
    [Resumen] En relación con rocas metamórficas de edad Precámbrica y metamorfismo de grado medio-alto se han estudiado más de 60 masas de pegmatitas cuarzo-feldespáticas compuestas por cuarzo, feldespato potásico, albita, moscovita, turma1 ina, granate, biotita, menas metálicas, minerales de uranio y otros. Las masas pegmatíticas son de formas irregulares o 1entejonares subconcordantes con la esquistosidad regional más manifiesta. Sus dimensiones oscilan entre unos decímetros y decenas de metros, y su continuidad lateral su pera en algunos casos los trescientos metros. Considerando sólo las masas de potencia métrica, por sus reservas, cal idad química de sus principales especies minerales, tamaño de grano, texturas, etc. es planteable la obtención industrial de cuarzo, feldespato potásico, feldespato sódico y moscovita[Abstract] More than 60 outcrops of quartz-fe1despatic pagmatites have been studied re1ated with Precambrian metamorphic rocks of medium-high grade. The pagmatites are composed of quartz, potash fe1dspar, a1bite, muscovite, turma1 ine, garnet, biotite, ores, uranium minerals and others. The pegmatite outcrops hare irregular o lenticular forms, subparallell to the main regional schistosity. They vary in size between a few decimeters to some tens of meters, whi1e su lateral continuity exceed in sorne cases 300 meterse By taking into account on1y the outcrop of metric size, their stocks, chemica1 qual ity of the main mineral species, grain size, texture, etc., it can be planned the industrial recovery of quartz, potash feldspar, sodic fe1dspar and muscovit

    Non-Normality as a Predictor of Participation in Bullying: Valuation in Victims and Aggressors

    Get PDF
    Bullying is related to several variables, including diversity and variables that place the victim outside of normality. However, it is not easy to find a single meaning of normality. The present study has two main objectives: to find out whether victims are evaluated as non-normal and to find out whether aggressors are evaluated as non-normal. A cross-sectional, correlational, and quantitative study was designed, focusing on a representative sample of secondary school students from the Community of Madrid. The sample consisted of 2076 participants and was constructed using a stratified, proportional, and random sampling technique. To gather this information, a questionnaire was constructed. It includes a first section where sociodemographic and normality information is collected, and a second section made up of the Defensor del pueblo-UNICEF Bullying Questionnaire. The reliability and consistency of the questionnaire are acceptable (Cronbach’s alpha 0.91). For the comparison of means between groups, a Student’s t-test was applied, and the correlation between variables was calculated by applying the bivariate correlation test. Results show that victims are evaluated as non-normal while aggressors are perceived as normal. This implies that the risk of being involved in bullying situations as a victim can be predicted. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

    On the Environmental Dependence of Cluster Galaxy Assembly Timescale

    Get PDF
    We present estimates of CN and Mg overabundances with respect to Fe for early-type galaxies in 8 clusters over a range of richness and morphology. Spectra were taken from the Sloan Digital Sky Survey (SDSS) DR1, and from WHT and CAHA observations. Abundances were derived from absorption lines and single burst population models, by comparing galaxy spectra with appropriately broadened synthetic model spectra. We detect correlations between [Mg/CN] and [CN/Fe] and cluster X-ray luminosity. No correlation is observed for [Mg/Fe]. We also see a clear trend with the richness and morphology of the clusters. This is interpreted given varying formation timescales for CN, Mg and Fe, and a varying star formation history in early-type galaxies as a function of their environment: intermediate-mass early-type galaxies in more massive clusters are assembled on shorter timescales than in less massive clusters, with an upper limit of ~1 Gyr.Comment: Accepted for publication in ApJ Letter

    Materiales silico-carbonosos en el Precámbrico de Sierra Morena

    Get PDF
    [Resumen] Se aborda, por primera vez, un estudio comparativo de las cuarcitas negras del Precámbrico de Sierra Morena, evidenciando su carácter de rocas sílico-carbonosas, asociadas a sucesiones con importantes aportes volcánicos y producidas por precipitaci6n química-bioquímica de sílice en medios marinos someros y restringidos. Se discute su distribuci6n, valor en la correlación es tratigráfica, evoluci6n textural con el aumento del metamorfismo y la deformación y algunos de los caracteres generales de su quimismo y mineralogíaAbstract] A comparative study of the black quarzites of the Precambrian of Sierra ~orena is atte~pted here for the 'first time, which reveals their character of silicacarbonaceous rocks related to succesion with important volcanic contributions and produced by chemical-biochemical precipitacion of silica in restricted and shallow marine environments. It is discussed their distribution value in .stratigraphical correlation, textural evolution with increasing rnetamorfism ando deformation, and sorne of the general character of its chemistry and mineralog

    HPLC-ESI-TOF-MS chemical characterization of comfrey root extract obtained by subcritical water extraction

    Get PDF
    In this work, a study on phytochemical profiles of comfrey (Symphytum officinale L.) root extract obtained by subcritical water extraction (SWE) has been carried out. Chemical composition was assessed by high-performance liquid chromatography coupled with electrospray time-of-flight mass spectrometry (HPLC-ESI-TOF-MS) identifying 22 compounds including organic acids, phenolic acids, flavonoids and fatty acids. Great number of phenolic acids and flavonoids were found in the extract obtained by SWE, with citric acid, caffeic acid and derivative, salvianolic acid B, hydroxybenzoic acid, syringetin-3-O-glucoside and quercetin 3-O-malonylglucoside as the most abundant compounds. Moreover, quercitin-3- malonylglucoside isomers, hydroxybenzoic acid glucoside, cirismaritin isomers, p-coumaric acid, hydroxycoumarin and methylcoumarin, among others, were identified for the first time in S. officinale root. Overall, the results indicate the potential of SWE for the production of highquality plant extracts from S. officinale root

    Structure–Biological Activity Relationships of Extra-Virgin Olive Oil Phenolic Compounds: Health Properties and Bioavailability

    Get PDF
    Extra-virgin olive oil is regarded as functional food since epidemiological studies and multidisciplinary research have reported convincing evidence that its intake affects beneficially one or more target functions in the body, improves health, and reduces the risk of disease. Its health properties have been related to the major and minor fractions of extra-virgin olive oil. Among olive oil chemical composition, the phenolic fraction has received considerable attention due to its bioactivity in different chronic diseases. The bioactivity of the phenolic compounds could be related to different properties such as antioxidant and anti-inflammatory, although the molecular mechanism of these compounds in relation to many diseases could have different cellular targets. The aim of this review is focused on the extra-virgin olive oil phenolic fraction with particular emphasis on (a) biosynthesis, chemical structure, and influence factors on the final extra-virgin olive oil phenolic composition; (b) structure–antioxidant activity relationships and other molecular mechanisms in relation to many diseases; (c) bioavailability and controlled delivery strategies; (d) alternative sources of olive biophenols. To achieve this goal, a comprehensive review was developed, with particular emphasis on in vitro and in vivo assays as well as clinical trials. This report provides an overview of extra-virgin olive oil phenolic compounds as a tool for functional food, nutraceutical, and pharmaceutical applications.Junta de Andalucía B-AGR-466-UGR1

    Zonación metamórfica en el área Monesterio-Fuente de Cantos: criterios texturales y mineralógicos

    Get PDF
    [Resumen] En el sector central del denominado "anticlinorio 0livenza-Monesterio", en los materiales del Proterozoico superior afectados por un metamorfismo progresivo que alcanza condiciones anatécticas, se ha establecido una zonaci6n metamórfica para los grados bajo y medio, basada en el estado de evolución textural de diferentes 1itologias y caracteres ópticos de distintos minerales, en especial la biotita, en las rocas metape1iticas y metagrauváquicas.Abstract] In the central part of the so-called "anticlinorium 0livenza-Monesterio", in Upper Proterozoic materials affected by a progressive metamorphism which reach to anatectic condicions, a rnetamorphic zonation has been stab1ished for the 10w and middle metamorphic degrees based on the state of textural evolution of several lithologies and in the optical features of different minera1s, mainly the biotite, in metapelithic and metagrauwakic rock
    corecore