Search results for "CEM"

Recurrent Mesolithic–Neolithic occupation at Sise (western Latvia) and shoreline displacement in the Baltic Sea Basin

2016

A major assemblage of Mesolithic and Neolithic wooden artefacts has been recovered from the bed of the River Užava at Sise, in the coastal belt of western Latvia. New archaeological investigation has also produced wooden remains and other evidence of occupation on the riverbank. On the basis of multi-proxy environmental data and radiocarbon dating, this article offers a first attempt to place the human activity in a palaeolandscape context. The earliest evidence of human presence is provided by wooden artefacts dated to c. 10,500–9700 cal. BP, during the Ancylus Lake transgression. These remains are thought to reflect fishing activities in the shallows of the Ventspils Bay, which existed d…

Monitoring displacements of an earthen dam using GNSS and remote sensing

2014

This paper shows the results of a scientific research in which a GNSS continuous monitoring system for earth-dam deformations has been developed, then, deformations have been related with reservoir water surface and level. The experiment was conducted near Bivona (Sicily, Italy), on the Castello dam (Magazzolo Lake). On the top of the dam three control points were placed and three GNSS permanent stations were installed. The three stations continuously transmitted data to the control centre of the University of Palermo. The former has been determined using freely available satellite data (specifically Landsat 7 SLC-Off) collected during the whole study period (DOYs 101 to 348 2011). Issues r…

Il destino delle cupole, tra crolli, demolizioni, consolidamenti e ricostruzioni_The destiny of domes, through collapses, demolitions, reinforcements…

2017

Le cupole sono sempre state opere di grande impegno costruttivo e di sperimentazione statica. L’ardita realizzazione o il semplice mancato crollo delle stesse rendeva celebre il progettista e la fabbrica in cui la cupola veniva inserita (spesso anche in un secondo momento, rispetto al primigenio nucleo), allo stesso modo i frequenti collassi ed i dissesti ne segnavano gli insuccessi e le qualità, sia nelle ricostruzioni che nei consolidamenti. Se il sisma costituiva il pericolo maggiore, non minore era il rischio correlato alla costruzione malfatta, prassi costante in aree marginali, che veniva spesso mascherata da finiture di alta qualità. I frequenti disastri fin dall’epoca post-rinascime…

Adapting to Dynamic LEO-B5G Systems : Meta-Critic Learning Based Efficient Resource Scheduling

2022

Low earth orbit (LEO) satellite-assisted communications have been considered as one of key elements in beyond 5G systems to provide wide coverage and cost-efficient data services. Such dynamic space-terrestrial topologies impose exponential increase in the degrees of freedom in network management. In this paper, we address two practical issues for an over-loaded LEO-terrestrial system. The first challenge is how to efficiently schedule resources to serve the massive number of connected users, such that more data and users can be delivered/served. The second challenge is how to make the algorithmic solution more resilient in adapting to dynamic wireless environments.To address them, we first…

Signal Processing for Image Enhancement and Multimedia Processing

2008

Etude de l'influence de l'hydratation des laitiers sur les propriétés de transfert gazeux dans les matériaux cimentaires

2015

Cements with high slag content are currently studied as possible candidate for nuclear waste containment materials. In this context it is important to know their microstructure and the transport properties (permeability and diffusion) of the gases that are formed by the radiolysis of the water present in this material. According to literature, these properties are strongly impacted by the addition of blast furnace slag. The aim of this work is to correlate the hydration processes of slag blended cements with their transport properties. In the first part of this work, the hydration of the slag blended cements, for which only few results have been reported to date, has been studied. Silicon-2…

Al-27 and Si-29 Solid-State NMR Characterization of Calcium-Aluminosilicate-Hydrate

2012

International audience; Calcium silicate hydrate (C-S-H) is the main constituent of hydrated cement paste and determines its cohesive properties. Because of the environmental impact of cement industry, it is more and more common to replace a part of the clinker in cement by secondary cementitious materials (SCMs). These SCMs are generally alumina-rich and as a consequence some aluminum is incorporated into the C-S-H. This may have consequences on the cohesion and durability of the material, and it is thus of importance to know the amount and the location of Al in C-S-H and what the parameters are that control these features. The present paper reports the Si-29 and Al-27 MAS NMR analyses of …

Broadband photocurrent enhancement in a-Si:H solar cells with plasmonic back reflectors

2014

The authors acknowledge Francesco Ruffino for the AFM measurements. This work was funded by the EU FP7 Marie Curie Action FP7-PEOPLE-2010-ITN through the PROPHET project (Grant No. 264687), the bilateral CNR/AVCR project "Photoresponse of nanostructures for advanced photovoltaic applications", the MIUR project Energetic (Grant no. PON02_00355_3391233) and by the Portuguese Science Foundation (FCT-MEC) through the Strategic Project PEst-C/CTM/LA0025/2013-14 and the research project PTDC/CTM-ENE/2514/2012. Plasmonic light trapping in thin film silicon solar cells is a promising route to achieve high efficiency with reduced volumes of semiconductor material. In this paper, we study the enhance…

Timing performance of the silicon PET insert probe

2010

Simulation indicates that PET image could be improved by upgrading a conventional ring with a probe placed close to the imaged object. In this paper, timing issues related to a PET probe using high-resistivity silicon as a detector material are addressed. The final probe will consist of several (four to eight) 1-mm thick layers of silicon detectors, segmented into 1 x 1 mm(2) pads, each pad equivalent to an independent p + nn+ diode. A proper matching of events in silicon with events of the external ring can be achieved with a good timing resolution. To estimate the timing performance, measurements were performed on a simplified model probe, consisting of a single 1-mm thick detector with 2…

Comparison of Intensity-based B-splines and Point-to-Pixel Tracking Techniques for Motion Reduction in Optical Mapping

2016

Suppression of motion artifacts (MA) in cardiac optical mapping usually requires uncoupling of cardiac contraction by restriction techniques, which are known to have important effects on cardiac physiology deteriorating the quality of acquisitions and their interpretation. In this study, we propose to assess the performance of two independent intensity-based post-processing strategies to minimize MAs during registration. A point-to-pixel block-matching classical similarity-based tracking with displacement interpolation is compared to a well-known non-rigid registration algorithm where the deformation field is obtained using cubic splines. Both strategies were tested on synthetic and real op…