92 research outputs found
Removal of chromium (III) by two-aqueous phases extraction
Two-aqueous phase extraction of chromium (III) as a solute from their aqueous solutions was investigated using polyethoxylated alcohols (CiEj) as a biodegradable non-ionic surfactant in the presence of anionic sodium dodecylbenzene sulfonate (SDBS). First, the combined effects of chromium and surfactants mixture (anionic and non-ionic) on the cloud point temperature were determined. After this, the phase diagrams of binary systems waterâsurfactant (NW342 and C10E3) were traced. According to the given surfactants concentration, the extracted solute reached 98.5% and 60% for NW342 and C10E3, respectively at pH equal to 3. The addition of sodium chloride lowers the cloud point temperature of surfactant where the phenomenon of salting-out was pronounced. Under the optimal extraction conditions, the suggested extraction mechanism is based on chromium species-NW342 non-ionic surfactant micelles solvatation. Since, the prevalence species (93.82%) were Cr(III)4(OH)66+, given by a theoretical calculation using CHEAQS V. L20.1. The first stage regeneration of NW342 surfactant was 27.82% at pH equal to 4.23 factorial designs were employed for screening the factors that would influence the overall optimization of a batch procedure of sorption
Spatiotemporal bioaccumulation of lead, cadmium, zinc and copper metals in lettuce sea Ulva lactuca harvest in two Algerian West Coasts
This work brings an evaluation of the quality of littoral zone of Algerian in two neighbouring port coasts, namely, Honaine and Beni Saf, chosen as significant discharge sites. This was followed by a comparison of the state of these coasts with those of the Mediterranean coastal areas. The study was conducted in all seasons in the year 2011-2012 by measuring the hydrological physicochemical parameters (pH, temperature, turbidity and salinity) and using sea lettuce Ulva lactuca as significant 'biomarker of the quantity of metal contaminants (Cd, Pb, Cu and Zn)'. Harvesting of Ulva and the seawater samples were performed in each season in three stations, characterised by discharges of waste and industrial water and saline discharges from the recent installation of desalination in Honaine. The metal concentrations in seawater showed significant variations between stations and the harvest season, resulting in the appearance of pollution of Cd, Pb, Cu and Zn. Also this result was manifested in Ulva in the station S1 (Beni Saf) and S2 (Honaine-beach) with the exception of copper. These results have exceeded tolerable international standards.Universidad de Tlemcen, ArgeliaUniversidad de Sevill
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Multi-perspective, Multi-modal Image Registration and Fusion
Multi-modal image fusion is an active research area with many civilian and military applications. Fusion is defined as strategic combination of information collected by various sensors from different locations or different types in order to obtain a better understanding of an observed scene or situation. Fusion of multi-modal images cannot be completed unless these two modalities are spatially aligned. In this research, I consider two important problems. Multi-modal, multi-perspective image registration and decision level fusion of multi-modal images. In particular, LiDAR and visual imagery. Multi-modal image registration is a difficult task due to the different semantic interpretation of features extracted from each modality. This problem is decoupled into three sub-problems. The first step is identification and extraction of common features. The second step is the determination of corresponding points. The third step consists of determining the registration transformation parameters. Traditional registration methods use low level features such as lines and corners. Using these features require an extensive optimization search in order to determine the corresponding points. Many methods use global positioning systems (GPS), and a calibrated camera in order to obtain an initial estimate of the camera parameters. The advantages of our work over the previous works are the following. First, I used high level-features, which significantly reduce the search space for the optimization process. Second, the determination of corresponding points is modeled as an assignment problem between a small numbers of objects. On the other side, fusing LiDAR and visual images is beneficial, due to the different and rich characteristics of both modalities. LiDAR data contain 3D information, while images contain visual information. Developing a fusion technique that uses the characteristics of both modalities is very important. I establish a decision-level fusion technique using manifold models
Multiple View Analysis of Designs
During design formulation, designs are subjected to an evaluation and verification process, the goal of which is the detection of design errors. The analysis of different designs or "views" using different design notations has been proposed to achieve this goal. The formal support for the use of multiple views at the design stage with the purpose to detect design discrepancies has been provided by the static analysis technique called abstract interpretation, as the analysis environment. Each view is formalized, independently analyzed, that is, each formalized view is checked for validity (it does not contain any cycles, the balancing rule is enforced, and does not contain any undefined entities). The multiple view analysis framework, relying on the abstract interpretation basis, compares two abstract views, and identifies discrepancies between them. The type of design discrepancies identified were omission of information, incompatible information, and inconsistencies between views. Key..
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