Search results for "artificial"
showing 10 items of 7394 documents
Speciation of Organic Matter in Natural Waters-interaction of polyacrylates and polymethacrylates with major cation components of seawater
2004
Abstract The speciation of some high molecular weight polycarboxylates was studied in different ionic media. Polyacrylates here investigated ( W =2.0, 5.1 and 20.0 kDa) form weak species with alkali metal cations ( K =10 2 mol l −1 , t =25 °C, I =0 mol l −1 ) and quite stable complexes with alkaline earth metal cations ( K >10 6 mol l −1 , t =25 °C, I =0 mol l −1 ). Results are reported from experiments performed in a multicomponent electrolyte solution simulating the major composition of seawater (artificial seawater). Protonation constants in this medium are expressed as a polynomial function of S 1/2 ( S =salinity) and the sharp lowering with respect to values obtained in non-interacting…
The interaction of amino acids with the major constituents of natural waters at different ionic strengths
2000
Abstract The interaction of amino acids with the major constituents of natural waters has been studied potentiometrically by determining protonation constants at different ionic strengths (e.g., I ≤5.6 mol (kg H 2 O) −1 (NaCl)) and in artificial seawater (containing Na + , K + , Ca 2+ , Mg 2+ , Cl − and SO 4 2− ) at different salinities. For glycine determinations in mixed NaCl–MgCl 2 , electrolyte solutions were also performed. The data included in this work, together with some already published, make it possible to calculate parameters for dependence on ionic strength using different models, i.e. an extended Debye–Huckel type equation and Pitzer equations. The results can be interpreted b…
Lateral organization of G M1 in phase-separated monolayers visualized by scanning force microscopy
2002
Phase separation of glycolipids in lipid mono- and bilayers is of great interest for the understanding of membrane function. The distribution of the ganglioside GM1 in sphingomyelin (SM)/1-palmitoyl-2-oleoyl- sn-glycero-3-phosphocholine (POPC), SM/1,2-dipalmitoyl- sn-glycero-3-phosphocholine (DOPC) and SM/cholesterol/POPC Langmuir-Blodgett (LB) monolayers transferred at 36 mN/m has been studied by scanning force microscopy. Besides lateral organization of the glycolipid in LB monolayers as deduced from topography, material properties have been investigated by phase imaging, pulsed force mode and force modulation microscopy. It was shown that GM1 preferentially clusters in an ordered lipid m…
Speciation of low molecular weight ligands in natural fluids: protonation constants and association of open chain polyamines with the major component…
2000
Abstract The interaction of five open chain polyamines (ethylenediamine (en), diethylenetriamine (dien), trietylenetetramine (trien), tetraethylenepentamine (tetren), spermine (sper)) with the major components of seawater was studied potentiometrically at 25°C, in an artificial seawater (containing Na+, K+, Mg2+, Ca2+, Cl− and SO42−) at different salinities (5–45‰). Potentiometric data were interpreted in terms of both the apparent protonation constants of polyamines and the formation constants of complexes formed by unprotonated or protonated amines and the cation and the anion of seawater (the inorganic content of seawater being considered as a single 1:1 salt). Some empirical relationshi…
Machine learning for rapid mapping of archaeological structures made of dry stones – Example of burial monuments from the Khirgisuur culture, Mongoli…
2020
11 pages; International audience; The present study proposes a workflow to extract from orthomosaics the enormous amount of dry stones used by past societies to construct funeral complexes in the Mongolian steppes. Several different machine learning algorithms for binary pixel classification (i.e. stone vs non-stone) were evaluated. Input features were extracted from high-resolution orthomosaics and digital elevation models (both derived from aerial imaging). Comparative analysis used two colour spaces (RGB and HSV), texture features (contrast, homogeneity and entropy raster maps), and the topographic position index, combined with nine supervised learning algorithms (nearest centroid, naive…
Towards the Preservation and Dissemination of Historical Silk Weaving Techniques in the Digital Era
2019
Historical weaving techniques have evolved in time and space giving as result more or less fabrics with different aesthetical characteristics. These techniques were transferred along the main silk production centers, thanks to the European Silk Road and creating a common European Frame on themes and techniques. These had made it complicated to determine whether a fabric corresponds to one century or another. Moreover, in order to understand their creation, it is necessary to determine the number of weaves and interlacements that each textile has, therefore, mathematical models can be extracted from these layers. In this sense, three dimensional (3D) virtual representations of the internal s…
Color degradation mapping of rock art paintings using microfading spectrometry
2021
[EN] Rock art documentation is a complex task that should be carried out in a complete, rigorous and exhaustive way, in order to take particular actions that allow stakeholders to preserve the archaeological sites under constant deterioration. The pigments used in prehistoric paintings present high light sensitivity and rigorous scientific color degradation mapping is not usually undertaken in overall archaeological sites. Microfading spectrometry is a suitable technique for determining the light-stability of pigments found in rock art paintings in a non-destructive way. Spectral data can be transformed into colorimetric information following the recommendations published by the Commission …
Mosaic floors of roman Villa del Casale: Principal component analysis on spectrophotometric and colorimetric data
2013
Abstract Spectrophotometric and colorimetric data obtained during a measurement campaign aimed at supporting the Roman "Villa del Casale" (Piazza Armerina, Sicily, Italy) conservation activities, are presented. Special attention was paid to the possible variation of the chromatic coordinates, possibly due to the interventions of cleaning, consolidation, and protection. Data have been analyzed by the Principal Component Analysis (PCA) statistical technique, with the attempt to investigate its role in data variability reduction and verify its effectiveness in interpreting the phenomena occurring on the mosaic surface of the Villa, through grouping the observations into homogenous clusters. Ef…
Deep learning to detect built cultural heritage from satellite imagery. - Spatial distribution and size of vernacular houses in Sumba, Indonesia -
2021
Abstract In Sumba Island – Indonesia, the implantation of vernacular houses, inside and outside traditional villages, is considered to be an efficient proxy for the on-going complex cultural transformations resulting from globalization. This study presents an easily reproducible workflow allowing buildings to be automatically detected from satellite imagery, demonstrating how modern computer vision methods based on deep learning can help in this task, which would be far too time-consuming when undertaken by hand. Eight deep learning architectures based on convolutional neural networks were compared in terms of ability to identify and locate precisely traditional houses from satellite images…
Artificial neural network decision support tool for assessment of the energy performance and the refurbishment actions for the non-residential buildi…
2017
The public buildings sector represents one of the most intensive items of EU energy consumption; the application of retrofit solutions in existing buildings is a crucial way to reduce its impact. To facilitate the knowledge of the energy performance of existing non-residential buildings and the choice of the more adequate actions, Public Administrations (PA) should have the availability of proper tools. Within the Italian project "POI 2007-13", a database and a decision support tool, for easy use, even to a non-technical user, have been developed. A large set of data, obtained from the energy audits of 151 existing public buildings located in four regions of South Italy have been analysed, …