40 research outputs found
Impact of Po Valley emissions on the highest glacier of the Eastern European Alps
Abstract. In June 2009, we conducted the first extensive glaciological survey of Alto dell'Ortles, the uppermost glacier of Mt. Ortles (3905 m a.s.l.), the highest summit of the Eastern European Alps. This section of the Alps is located in a rain shadow and is characterized by the lowest precipitation rate in the entire Alpine arc. Mt. Ortles offers a unique opportunity to test deposition mechanisms of chemical species that until now were studied only in the climatically-different western sector. We analyzed snow samples collected on Alto dell'Ortles from a 4.5 m snow-pit at 3830 m a.s.l., and we determined a large suite of trace elements and ionic compounds that comprise the atmospheric deposition over the past two years. Trace element concentrations measured in snow samples are extremely low with mean concentrations at pg gâ1 levels. Only Al and Fe present median values of 1.8 and 3.3 ng gâ1, with maximum concentrations of 21 and 25 ng gâ1. The median crustal enrichment factor (EFc) values for Be, Rb, Sr, Ba, U, Li, Al, Ca, Cr, Mn, Fe, Co, Ga and V are lower than 10 suggesting that these elements originated mainly from soil and mineral aerosol. EFc higher than 100 are reported for Zn (118), Ag (135), Bi (185), Sb (401) and Cd (514), demonstrating the predominance of non-crustal depositions and suggesting an anthropogenic origin. Our data show that the physical stratigraphy and the chemical signals of several species were well preserved in the uppermost snow of the Alto dell'Ortles glacier. A clear seasonality emerges from the data as the summer snow is more affected by anthropogenic and marine contributions while the winter aerosol flux is dominated by crustal sources. For trace elements, the largest mean EFc seasonal variations are displayed by V (with a factor of 3.8), Sb (3.3), Cu (3.3), Pb (2.9), Bi (2.8), Cd (2.1), Zn (1.9), Ni (1.8), Ag (1.8), As (1.7) and Co (1.6). When trace species ratios in local and Po Valley emissions are compared with those in Alto dell'Ortles snow, the deposition on Mt. Ortles is clearly linked with Po Valley summer emissions. Despite climatic differences between the Eastern and Western Alps, trace element ratios from Alto dell'Ortles are comparable with those obtained from high-altitude glaciers in the Western Alps, suggesting similar sources and transport processes at seasonal time scales in these two distinct areas. In particular, the large changes in trace element concentrations both in the Eastern and Western Alps appear to be more related to the regional vertical structure of the troposphere rather than the synoptic weather patterns
Modeling Single Electron Transfer in Si:P Double Quantum Dots
Solid-state systems such as P donors in Si have considerable potential for
realization of scalable quantum computation. Recent experimental work in this
area has focused on implanted Si:P double quantum dots (DQDs) that represent a
preliminary step towards the realization of single donor charge-based qubits.
This paper focuses on the techniques involved in analyzing the charge transfer
within such DQD devices and understanding the impact of fabrication parameters
on this process. We show that misalignment between the buried dots and surface
gates affects the charge transfer behavior and identify some of the challenges
posed by reducing the size of the metallic dot to the few donor regime.Comment: 11 pages, 7 figures, submitted to Nanotechnolog
Flash flood warning in ungauged basins by use of the Flash Flood Guidance and model-based runoff thresholds
Combined Use of Sentinel-1 and Sentinel-2 for Glacier Mapping: an Application over Central East Alps
The systematic monitoring of glaciers is essential to both evaluate water resource availability and better understand the
effects of climate change. The increased speed of glacier changes observed in the past few years requires a more frequent update of the glacier inventories than in the past; however, the high human supervision required by the state-of-the-art techniques is discouraging their systematic application over large areas. This article proposes a novel approach to exploit the large volume of data provided by Copernicus Sentinel missions for detecting glacier outlines, including debris-covered glaciers. In detail, our method exploits the Sentinel-1 and Sentinel-2 multitemporal images to build a composite image representing the glacier conditions during the yearly maximum ablation period. The Sentinel-2 multispectral images are classified with a support vector machine and composed to a mosaic that represents the information of the maximum glacier ablation. At the same time, the Sentinel-1 time series are exploited to build a multitemporal coherence composite that represents all the snow-covered and glaciated areas together with all the moving surfaces. This information is used together with the Sentinal-2 composite to detect the debris-covered part of the glaciers. The proposed method was tested in the Central East Alps and presented an overall accuracy of 92% with respect to a reference inventory over South Tyrol and an agreement of 90% with respect to the latest glacier inventory of the Alps from Sentinel-2. The proposed approach enables to assist glacier experts in identifying glacier outlines over large areas and in short time
A robotic vehicle for freight delivery in urban areas
The authors present new concept architecture of light duty full electrical vehicle for efficient sustainable urban freight transport that allows the movement of two Euro Pallets 800x1200 mm (or boxes with similar bottom part). Following a sustainable and efficient mobility approach, a robotic handling device has been designed and positioned on-board of the vehicle. The handling device realizes the loading-unloading operations on the right side of the vehicle and from the ground to the vehicle platform. Active suspensions of the vehicle have been designed to adapt the stiffness to the payload and at modifying the chassis height on the ground for travel and loading-unloading tasks
A new robotized vehicle for urban freight transport
In recent years, the research in the field of urban area delivery drew the attention of the scientific world. Many problems arise from the lack of a well-defined urban logistic, aimed at an efficient parcels distribution. Also technological issues arise; the current technology does not satisfy the needs of this specific context, in particular for what it concerns the vehicles and the transportation process. In this research we present the FURBOT vehicle result of the FURBOT (Freight Urban RoBOTic) project, funded within the Seventh Framework Programme of the European Union, which aim is to develop a new vehicle to improve the urban freight transport. The vehicle represents an integration between a mobile robot, a van and a forklift. The new vehicle design is presented