Search results for "feature"
showing 10 items of 4091 documents
Submerged speleothems and sea level reconstructions: a global overview and new results from the Mediterranean Sea
2021
This study presents a global overview of the submerged speleothems used to reconstruct paleo sea levels and reports new results from two stalactites collected in the Mediterranean Sea. Coastal cave deposits significantly contributed to the understanding of global and regional sea-level variations during the Middle and Late Quaternary. The studied speleothems cover the last 1.4 Myr and focused mainly on Marine Isotope Stages (MIS) 1, 2, 3, 5.1, 5.3, 5.5, 7.1, 7.2, 7.3 and 7.5. The results indicate that submerged speleothems represent extraordinary archives that can provide detailed information on former sea-level changes. The two stalactites collected in the central Mediterranean Sea, at Fa…
Vermetid reefs in the Mediterranean Sea as archives of sea-level and surface temperature changes
2011
Vermetid reefs are among the most important bioconstructions in the Mediterranean Sea, with a distribution restricted to the warmest part of the basin. Their structure, and vertical and geographical distribution make them good biological indicators of changes in sea level and sea-surface temperature over the last two millennia.
A hybrid multi-objective optimization algorithm for content based image retrieval
2013
Abstract Relevance feedback methods in CBIR (Content Based Image Retrieval) iteratively use relevance information from the user to search the space for other relevant samples. As several regions of interest may be scattered through the space, an effective search algorithm should balance the exploration of the space to find new potential regions of interest and the exploitation of areas around samples which are known relevant. However, many algorithms concentrate the search on areas which are close to the images that the user has marked as relevant, according to a distance function in the (possibly deformed) multidimensional feature space. This maximizes the number of relevant images retriev…
Effect of Impregnation and Activation Conditions of Al2O3/CuO Supported Monolith Catalysts in the Reduction of NO
1979
Reduction of NO in the presence of CO and Ar was examined on two series of monolithic sheets carrying an active CuO/Al 2 O 3 layer. In the impregnation procedure the ratio of Al 2 O 3 to CuO was varied in a wide range. The texture of the layer and the dispersion of CuO therein was controlled by mercury porosimetry, scanning electron microscopy and secondary ion mass spectrometry (SIMS). It could be established that the surface concentration of CuO determined by SIMS measurements is the most decisive quantity of the catalyst correlating linearly with the conversion of NO.
The use of constructed wetlands for the treatment and reuse of urban wastewater for the irrigation of two warm-season turfgrass species under Mediter…
2017
Constructed wetlands (CWs) represent low-cost technology for the treatment and reuse of wastewater in urban areas. This study aimed to evaluate the pollutant removal efficiency of a CW system and to assess the effects of irrigation using treated urban wastewater on soil and on two warm-season turf species. The research was carried out in Sicily (Italy) on a pilot-scale horizontal subsurface flow system which was fed with treated urban wastewater following secondary treatment from an activated-sludge wastewater treatment plant. The pilot system was located in an open urban park and comprised two separate parallel planted units. Experimental fields of Cynodon dactylon (L.) Pers. and Paspalum …
Elementary Integration Theory
1998
This section begins with the definitions and elementary properties of real and extended-real functions.
Long-term erosional responses after fire in the Central Spanish Pyrenees
2005
Abstract This paper reports the results of a study on how fire effects water and sediment losses in the Central Spanish Pyrenees where land abandonment results in an increase of the scrubland and fire-affected surfaces. In 1991, two plots (control and burnt) were installed to collect runoff, suspended sediments and solutes. One of the plots was burnt (burnt-1) and the other was covered by shrubs and herbs (control). During 1993, another burnt plot was installed (burnt-2). Data was collected from the three plots until 1999 and is used as the basis for assessing the soil erosion changes after the fire. Runoff, solute and suspended sediment concentration and erosion rates were slightly greater…
Anthropogenic units fingerprinted by REE in archaeological stratigraphy: Mas d'Is (Spain) case
2013
Abstract On occasions, archaeologists have to deal with serious difficulties to differentiate between processes that ultimately are responsible for the formation of stratigraphic units. Sometimes we face problems related with depositional units in multilayered deposits and other times, we ask for the character of some dark surface soils, very similar to natural paleosols and usually associated with archaeological findings. In both cases, the problems we must address concern the relative impact of human activities. The imbalance between anthropic and natural processes in the formation of archaeological deposits is crucial for a correct interpretation of the processes involved in the formatio…
A Taphonomic Perspective on Neolithic Beginnings: Theory, Interpretation, and Empirical Data in the Western Mediterranean
2001
The fills of caves and rockshelters generally comprise complex depositional palimpsests, making fine scale chronological resolution extremely difficult. Nevertheless, these settings remain very important in archaeology because they often preserve long records of cultural change. This is true for the initial appearance of food producing economies in the western Mediterranean. The chronologically ambiguous nature of cave and shelter deposits is one of the reasons for the continued debate over the processes responsible for the beginning of the Neolithic in this region. We employ taphonomic studies of the archeofaunal record from Mesolithic and early Neolithic cave and shelter sites in Mediterr…
Breccias of the Adnet Formation: indicators of a Mid-Liassic tectonic event in the Northern Calcareous Alps (Salzburg/Austria)
1995
Stratigraphy, lithology and depositional structures of Liassic red limestone-breccias of the Adnet Formation, including the ‘Adnet Scheck’, were studied at several outcrops of the Northern Calcareous Alps (NCA) south-east of Salzburg. A four-fold lithostratigraphic division is proposed for the Adnet Formation of the Osterhorn Mountains: the hemipelagic Schmiedwirt (Sinemurian) and Kehlbach (Carixian) members are separated from the pelagic Saubach Member (Toarcian) by a layer of amalgamated breccias (Scheck Member, probably Domerian to early Toarcian). Several other breccia beds occur locally from the base of the Kehlbach Member up to the lower Saubach Member. Although the sediments overlyin…