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In this work, the thermal performance enhancement of a shallow solar pond (SSP) was verified theoretically. The SSP operates under the open cycle to extract heat in order to increase own efficiency. SSP was provided with two transparent glass covers to reduce heat loss and increase global warming. It was also coated with a heat insulation material; the bottom of the SSP is painted in black to improve the absorption of solar radiation. In order to enhance heat extraction, five types of nanofluids with different physical properties were passed through a heat exchanger in the form of a serpentine welded to the bottom of the SSP. Five types of metal nanoparticles such as Al2O3, CuO, TiO2, SiO2, and Cu were mixed with pure water under various concentrations ranging from 0 to 5 % to obtain the nanofluids. A numerical model was developed based on the solution of thermal balance equations after discretization by using real meteorological conditions of the Medea city located in Algeria. The simulation was conducted on June 8 from 5 am to 6 am hours for the next day. The obtained results, including thermophysical properties, temperature of the pond and exergy performance, were presented and discussed. [ABSTRACT FROM AUTHOR]

This study is an attempt to characterize the chemical composition and antioxidant activity of olive leaves variety (namely Bouricha variety) that is very widespread in the East of Algeria. The aqueous extract (AE) of leaves was initially analyzed for its phenolic profile. Using the liquid chromatography coupled to tandem mass spectrometry analysis, it was possible to identify the predominant components in the AE of the leaves. This extract was hydrolyzed with acid and gave hydroxytyrosol (HT). AE and HT were evaluated for their 1,1-diphenyl-2-picrylhydrazyl radical scavenging capacity, ferric reducing antioxidant power and total antioxidant activity by phosphomolybdenum method. The antioxidant and anti-asthmatic activities of these extracts were examined in a model of experimental asthma in Wistar rats. For measuring the intensity of the airway inflammation, oxidative stress parameters were analyzed in lungs and a histological study of this tissue was performed. The obtained results showed that the sensitization of the ovalbumin (OVA) group induced lung inflammation and severe lipid peroxidation (LPO) revealed by a significant increase in malondialdehyde (MDA) levels and a decrease in the non-enzymatic and enzymatic antioxidant systems. However, the administration of AE and HT extracts significantly improved the antioxidant state in asthma disease and provided evidence for the relation between phenolic compounds and the high antioxidant activity of olive leaves extracts, especially HT more than AE.

Objectives: To analyze the clinico-biological manifestations, identify the causes and evaluate the outcome of patients with severe thrombotic microangiopathies admitted in a Tunisian intensive care unit., Methods: Retrospective study over a period of 10 years (1995-2004) in an intensive care unit., Results: Were included in this study 9 cases with a mean age of 29.2+/-9 years (range 15-44 years). Fever was observed in 5 patients, neurological impairment in 5 and digestive manifestations in 6. Haemolytic anaemia, thrombocytopenia and acute renal failure were observed in 100% of the cases. In our study, the aetiologies of thrombotic microangiopathies were: complicated pregnancy in 6 cases, systemic lupus erythematosus in 1 case. In contrast, no aetiology was found in 2 patients. Plasma exchange was performed in 5 patients, while 4 patients received only plasma infusion. After an average stay of 18+/-12.5 days, evolution was marked by the death 3 patients., Conclusion: The incidence of severe thrombotic microangiopathies is rare in Tunisian ICU. The clinical manifestations are not specific. Despite the improvement in the outcome by exogenous plasma supply, thrombotic microangiopathies with severe organ dysfunctions leading to hospitalization in the intensive care unit are associated with a high mortality rate.