Vegetation succession and climate change across the Plio-Pleistocene transition in eastern Azerbaijan, central Eurasia (2.77–2.45 Ma)

The Plio-Pleistocene transition marked a key moment in global climate history, characterised by the onset of major glaciations in the Northern Hemisphere. The palaeoenvironmental history of the Plio-Pleistocene transition is not well known for the Caspian Sea region, despite its importance for global climate dynamics. Here we present an independently 40Ar/39Ar dated, high-resolution terrestrial palynological record spanning the Plio-Pleistocene boundary based on a lacustrine-marine sedimentary sequence from eastern Azerbaijan. Despite complex pollen transport pathways and the proximity of closely stacked mountain vegetation belts in the Greater and Lesser Caucasus, the record shows that regional vegetation responded to Milankovitch forced glacial-interglacial cycles, tentatively correlated with global climatic records spanning MIS G8 to 98 (∼2.77–2.45 Ma). The persistence of mesophilous forests during glacial times indicates that some settings in the South Caspian Basin acted as glacial refugia, and that vegetation response to glaciations was muted by increased moisture availability, linked to Caspian transgression. The palynological record shows a relationship with global [delta]18O stacks and specifically to the obliquity record. We anticipate that precise correlation with the global climatostratigraphic timescale will allow better understanding of the nature and timing of important transgressive events in the Caspian Sea and their relevance on a global scale

Towards a new image processing system at Wendelstein 7-X: From spatial calibration to characterization of thermal events

Wendelstein 7-X (W7-X) is the most advanced fusion experiment in the stellarator line and is aimed at proving that the stellarator concept is suitable for a fusion reactor. One of the most important issues for fusion reactors is the monitoring of plasma facing components when exposed to very high heat loads, through the use of visible and infrared (IR) cameras. In this paper, a new image processing system for the analysis of the strike lines on the inboard limiters from the first W7-X experimental campaign is presented. This system builds a model of the IR cameras through the use of spatial calibration techniques, helping to characterize the strike lines by using the information given by real spatial coordinates of each pixel. The characterization of the strike lines is made in terms of position, size, and shape, after projecting the camera image in a 2D grid which tries to preserve the curvilinear surface distances between points. The description of the strike-line shape is made by means of the Fourier Descriptors

Forward modeling of collective Thomson scattering for Wendelstein 7-X plasmas: Electrostatic approximation

In this paper, we present a method for numerical computation of collective Thomson scattering (CTS). We developed a forward model, eCTS, in the electrostatic approximation and benchmarked it against a full electromagnetic model. Differences between the electrostatic and the electromagnetic models are discussed. The sensitivity of the results to the ion temperature and the plasma composition is demonstrated. We integrated the model into the Bayesian data analysis framework Minerva and used it for the analysis of noisy synthetic data sets produced by a full electromagnetic model. It is shown that eCTS can be used for the inference of the bulk ion temperature. The model has been used to infer the bulk ion temperature from the first CTS measurements on Wendelstein 7-X

Cleavage of 7- And 8-nitropyrido[1,2-a]benzimidazoles on treatment with dimethyl acetylenedicarboxylate

7-Nitropyrido[1,2-a]benzimidazole and 8-nitropyrido[1,2-a]benzimidazole undergo cleavage-recyclization under the action of an excess of dimethyl acetylenedicarboxylate

Cleavage of 7- And 8-nitropyrido[1,2-a]benzimidazoles on treatment with dimethyl acetylenedicarboxylate

7-Nitropyrido[1,2-a]benzimidazole and 8-nitropyrido[1,2-a]benzimidazole undergo cleavage-recyclization under the action of an excess of dimethyl acetylenedicarboxylate

Synthesis of 2-R-4,5,7-trimethyl-1-vinyl-4,5,6,7-tetrahydropyrrolo[3,2-c] pyridines

The synthesis of 1-vinyltetrahydropyrrolo[3,2-c]pyridines substituted at C(2) has been accomplished, based on 4,5,7-trimethyl-1-vinyl-4,5,6,7- tetrahydropyrrolo[3,2-c]pyridine and its 2-formyl-substituted derivative. © 2004 Springer Science+Business Media, Inc

Synthesis of 2-R-4,5,7-trimethyl-1-vinyl-4,5,6,7-tetrahydropyrrolo[3,2-c] pyridines

The synthesis of 1-vinyltetrahydropyrrolo[3,2-c]pyridines substituted at C(2) has been accomplished, based on 4,5,7-trimethyl-1-vinyl-4,5,6,7- tetrahydropyrrolo[3,2-c]pyridine and its 2-formyl-substituted derivative. © 2004 Springer Science+Business Media, Inc