Snow and ice play their most important role in the nitrogen cycle as a barrier to land-atmosphere and ocean-atmosphere exchanges that would otherwise occur. The inventory of nitrogen compounds in the polar ice sheets is approximately 260 Tg N, dominated by nitrate in the much larger Antarctic ice sheet. Ice cores help to inform us about the natural variability of the nitrogen cycle at global an...

Based on the theories of social representation (SC) and Central Core (CC), a structural study was undertaken regarding the neologism hanseniase (Hansen's disease), the term adopted by Brazil's Ministry of Health in the 1970s. Carried out during 2001, this study interviewed eight hundred housewives residing in the Rio de Janeiro and Duque de Caxias municipalities. It found that Hansen's disease ...

Abstract We drilled an 81.2-m-long ice core in the accumulation area (5860 m a.s.l.) of Trambau Glacier Rolwaling region during October–November 2019. The drilling operation was conducted with a lightweight electro-mechanical drill system after two reconnaissance fieldworks 2017 and 2018, which shallow firn cores were hand auger. samples transported by helicopters at high elevation 6000 a.s.l. ...

Segregation is one of the major phenomena decreasing durability concrete and increasing its risk failure. This paper investigates feasibility AC Impedance Spectroscopy (ACIS) to serve as a monitoring technique for segregation during compaction. The impedances fresh were determined between compaction intervals. Changes in calculated bulk resistivities compared hardened densities drilled cores, w...

Abstract In December 2007, an Mw2.2 earthquake occurred in a gabbroic dike at 3.3 km depth deep gold mine South Africa. The fore- and aftershock activity was analyzed effort to understand the preparation generation processes of earthquakes; these findings have already been published. present paper focuses on stress state source region mainshock. A 90-m-long borehole across mainshock fault drill...

Abstract. The microstructure of permafrost ground contains clues to its formation and hence preconditioning future change. We applied X-ray computed microtomography (CT) obtain high-resolution data (Δx=50 µm) the composition a 164 cm long core drilled in Yedoma upland north-eastern Siberia. CT analysis allowed microstructures be directly mapped volumetric contents excess ice, gas inclusions, tw...

Abstract A deep ice core was drilled at Dome A, Antarctic Plateau, East Antarctica, which started with the installation of a casing in January 2012 and reached 800.8 m 2017. To date, total 337 successful ice-core drilling runs have been conducted, including 118 to drill pilot hole. The time 52 days, eight days were required for down reaming hole, 44 coring. average penetration depths individual...

Understanding the evolution of river systems in southern Africa is fundamental to constrain landscape and sediment dispersal patterns. It widely considered that upper Zambezi River was connected with Limpopo during Cretaceous, forming what then largest Africa. Crustal flexure Paleogene severed drainage from Limpopo, setting framework modern systems. We present first evidence—based on heavy-mine...