Radionuclides measured on water bottle samples

Actinium is one of the rarest naturally occurring elements on earth. We measured its longest-lived isotope 227Ac (half-life 21.77 yr) for the first time in the water column of the Southeast Pacific, the Central Arctic, the Antarctic Circumpolar Current (ACC) and the Weddell Gyre (WG). Besides the profile in the Southeast Pacific, which confirms earlier findings about the role of diapycnal mixing for 227Ac distribution, we found three other different types of vertical profiles. These profiles point to a prominent role of advection for 227Ac distribution, especially in the Southern Ocean. Depending on the type of profile found, 227Ac is proposed as a tracer for different oceanographic questions. In the Southern Ocean, up to 4.93±0.32 dpm/m**3 227Ac is found close to the sea floor, which is the highest concentration ever observed in the ocean. Close to the sea surface in the WG, 0.46±0.05 dpm/m**3 227Acex (227Ac in excess of its progenitor 231Pa) is detected. We use 227Acex there to determine the upwelling velocity in the Eastern WG to be about 55 m/yr. In the ACC, Upper and Lower Circumpolar Deep Water (UCDW and LCDW) are found to differ clearly in their 227Acex activity. High 227Acex activities are therefore a promising tracer for recent inputs of LCDW to the sea surface, which may help to understand the role of deep upwelling for iron inputs into Antarctic surface waters. The expected release of 227Ac is compared with 228Ra to make sure that the large near-surface excess in the water column of the Southern Ocean is not due to lateral inputs by isopycnal mixing. Data from the Central Arctic and from a transect across the ACC confirm that 228Ra and 227Acex differ strongly in their sources. The first measurements of 227Ac on suspended matter (less than 1.7% of total 227Ac close to the sea floor) indicate that the particle reactivity of 227Ac is negligible in the open ocean, in agreement with earlier findings [Y. Nozaki, Nature 310 (1984) 486-488]. Despite the extremely low concentrations of 227Ac, new measurement techniques [W.S. Moore, R. Arnold, J. Geophys. Res. 101 (1996) 1321-1329] point to a comfortable and comparably simple determination of 227Ac in the future. Finally, 227Acex may become a widely used deep-sea specific tracer.

Results of a sediment profile and water analyses from Lake Hancza in northeastern Poland

We investigated the sedimentary record of Lake Hancza (northeastern Poland) using a multi-proxy approach, focusing on early to mid-Holocene climatic and environmental changes. AMS 14C dating of terrestrial macrofossils and sedimentation rate estimates from occasional varve thickness measurements were used to establish a chronology. The onset of the Holocene at c. 11600 cal. a BP is marked by the decline of Lateglacial shrub vegetation and a shift from clastic-detrital deposition to an autochthonous sedimentation dominated by biochemical calcite precipitation. Between 10000 and 9000 cal. a BP, a further environmental and climatic improvement is indicated by the spread of deciduous forests, an increase in lake organic matter and a 1.7% rise in the oxygen isotope ratios of both endogenic calcite and ostracod valves. Rising d18O values were probably caused by a combination of hydrological and climatic factors. The persistence of relatively cold and dry climate conditions in northeastern Poland during the first one and a half millennia of the Holocene could be related to a regional eastern European atmospheric circulation pattern. Prevailing anticyclonic circulation linked to a high-pressure cell above the retreating Scandinavian Ice Sheet might have blocked the influence of warm and moist Westerlies and attenuated the early Holocene climatic amelioration in the Lake Hancza region until the final decay of the ice sheet.

In occasione delle fauste nozze Giulio Zuccoli ed Aurora Rovetta bresciani : alcuni componimenti allusivi a Dante Alighieri.

Acquisition made accessible thanks to a 2015-2017 grant from the Council on Libraries and Information Resources.

Il conte Durante; racconto di Ausonio Vero [pseud.], per il sesto centenario di Dante.

Mode of access: Internet.

Fraseologia della Divina commedia e delle liriche di Dante Allighieri /

Vol. 1 of the author's "Manuale dantesco" (half-title).

The Divina commedia and Paradise lost reflect mediaevalism and the renaissance, catholicism and protestantism ...

Typewritten.

Forgotten Danteiana; a bibliographical supplement,

"Also published by the Dante society of Cambridge, Mass."--p. [2] of cover.

A concordance to the Batifolle letters,

"[An] appendix to our Concordance [to the Latin works of Dante] ... We have followed the text of the Società Alighieri [Dante's Opere, Firenze, 1921]"--Authors' pref.

Dante Alighieri : cattolico apostolico romano : scritti di Mauro Ricci.

La religione e la pietà di Dante -- Dante e Lutero.

Dante's Inferno as a forerunner of the reformation ...

Typewritten.

Opere.

Half-title; each v. has special t.p.

Dante in Frankreich bis zum Ende des XVIII. Jahrhunderts.

Mode of access: Internet.

Il primato artistico italiano; numero dedicato al centenario di Dante Alighieri,

Cover title.