Search results for "FEL"

Zircon evaporation ages and geochemistry of metamorphosed volcanic rocks from the Vinjamuru domain, Krishna Province: evidence for 1.78 Ga convergent…

2012

Palaeoproterozoic intermediate to potassic felsic volcanism in volcano-sedimentary sequences could either have occurred in continental rift or at convergent magmatic arc tectonic settings. The Vinjamuru domain of the Krishna Province in Andhra Pradesh, SE India, contains such felsic and intermediate metavolcanic rocks, whose geochemistry constrains their probable tectonic setting and which were dated by the zircon Pb evaporation method in order to constrain their time of formation. These rocks consist of interlayered quartz–garnet–biotite schist, quartz–hematite–baryte–sericite schist as well as cherty quartzite, and represent a calc-alkaline volcanic sequence of andesitic to rhyolitic rock…

Isotopic constraints on the age and formation of a Palaeoproterozoic volcanic arc complex in the Kedougou Inlier, eastern Senegal, West Africa

1997

Abstract The Palaeoproterozoic Kedougou basement in the Mako area in eastern Senegal consists of four major rock complexes: 1) high-grade amphibolitic and gneissic rocks occuring as large xenoliths (the Sandikounda amphibolite-gneiss complex); 2) voluminous bimodal volcanic rocks (the Mako volcanic-plutonic complex); 3) the Sandikounda layered plutonic complex; and 4) trondhjemitic to calc-alkaline intrusive granitoids (the Laminia-Kaourou plutonic complex). Zircons from xenoliths of the Sandikounda amphibolite-gneiss complex yielded ages of ∼2200 Ma, which are slightly older than those of the Mako Supergroup volcanic rocks. These xenoliths also have ɛNd(t) values ranging from +2.4 to +4.1.…

Norwegian Sociology and the Recognition of the Saami Minority

2014

At a time when the Saami ethnic minority got little attention by the Norwegian public and the political authorities of the country, sociologists did much to raise public awareness about the conditions of this ethnic minority. In the postwar period of the 1950s and 1960s, sociologists of Norway focused to a large degree on social groups that fell outside the emerging welfare state. Norwegian sociology has been characterized by an approach named “problem-oriented empirism” and also by sociologists playing a vital role as public intellectuals. Sociology professor Vilhelm Aubert (1922- 88) coined the term “problem-oriented empirism” to characterize Norwegian sociology from the end of the Second…

A lake fortress, a floating chronology, and an atmospheric anomaly: the surprising results of a radiocarbon wiggle-match from Āraiši, Latvia

2014

Abstract An Iron Age timber settlement which, in view of the defensive structures uncovered, is described as a lake fortress, on an island in Lake Āraiši, north-eastern Latvia, was excavated in 1965–69 and 1975–79 by teams led by Jānis Apals, who distinguished five construction phases. Dendrochronological analysis produced a c. 100-year floating chronology for Norway spruce (Picea abies (L.) Karst.) timbers from the earliest phase. A 14C wiggle-match was undertaken to obtain an absolute date range for the final year of the floating chronology, and thus for the construction of the settlement. Ten blocks of wood from one timber, each comprising 6-11 years and collectively spanning the whole 9…

100 Jahre Zeitschrift für Orthopädie

2008

The article affords insight into the one hundred years' history of the Journal of Orthopedics. The existing 130 volumes reflect the change in the orthopedic spectrum of illness, diagnostic investigation and treatment. Already in its first few years of existence, the journal was a forum for international exchange. Investigation of various epochs showed that the editors applied strict scientific standards in selecting the publication, despite basis changing historical conditions. They were able to prevent political interventions appreciably influencing the character of the journal. At the same time, the negative effects which the two world wars and National Socialism had on the further develo…

Models as Research Tools: Plücker, Klein, and Kummer Surfaces

2018

In the late summer of 1869, 20-year-old Felix Klein made his way to Berlin, where he planned to attend the renowned seminar founded by Ernst Eduard Kummer and Karl Weierstrass. Klein had already taken his doctorate in Bonn and he would soon be recognized as a leading expert on line geometry, a new approach to 3-space launched by his mentor in Bonn, Julius Plucker. Just before Plucker died in 1868, he entrusted Klein to complete the classic monograph, Neue Geometrie des Raumes gegrundet auf die Betrachtung der geraden Linie als Raumelement. Overall responsibility for this project fell to Alfred Clebsch in Gottingen, which was how Klein first came to the prestigious Georgia Augusta. There he …

Black Holes, Geons, and Singularities in Metric-Affine Gravity

2016

Uno de los problemas abiertos en la descripción de la gravedad es la existencia de singularidades. Las geometrías singulares se caracterizan por geodésicas incompletas, lo que físicamente se corresponde con observadores que desaparecen del espacio-tiempo, o que aparecen de la nada. Múltiples extensiones de la Relatividad General tratan de resolver este problema de algún modo. Por ello, en esta tesis estudio modificaciones al Lagrangiano de Relatividad General, tales como gravedad cuadrática y gravedad de Born-Infeld, en el formalismo Métrico-Afín. En este formalismo, la conexión (de la cual se derivan los tensores de curvatura) se considera independiente de la métrica, y permitimos que sea …

Enceintes néolithiques de Bourgogne

2002

L'article fait le point sur les enceintes néolithiques identifiées dans les départements bourguignons, principalement Yonne et Côte d'Or. On dénombre ainsi environ 180 sites aménagés défensivement. En plaine, les enceintes privilégient l'installation le long des cours d'eau principaux (Yonne, Armançon, Serein, cours amont de la Saône), à la confluence avec un ru de moindre importance dont le bassin versant s'ouvre sur un "arrière pays" qui offre des opportunités d'échanges. Ainsi s'esquisse un modèle d'occupation du territoire qui débute avec le Cerny et qui évolue jusqu'au Néolithique récent.

European Guidance Week 2017 : EU Presidency Conference on Lifelong Guidance Policy and Practice 27th-28th September 2017. Background paper

2017

Hidden attractors in electromechanical systems with and without equilibria

2016

This paper studies hidden oscillations appearing in electromechanical systems with and without equilibria. Three different systems with such effects are considered: translational oscillator-rotational actuator, drilling system actuated by a DC-motor and drilling system actuated by induction motor. We demonstrate that three systems experience hidden oscillations in sense of mathematical definition. While some of these hidden oscillations can be easily seen in natural physical experiments, the localization of others requires special efforts. peerReviewed