Search

ABSTRACTThe main objectives of our study were to highlight the annual incidence of Canine Leishmaniasis (CanL) in Algeria. A retrospective study was conducted on CanL in Algeria between 2010–2019, by means of a questionnaire survey of 30 canine veterinarians practising in the North central region, Algiers. The retrospective study showed 78 cases of Canine Leishmaniasis (2010 and 2019), with an average of 13.73 per year. The highest mean was observed in 2013:3.400, [1.517–5.283] 95%, with a significant difference (p = 0.028). The cross-sectional survey showed that 44.4% of canine leishmaniasis cases are prevalent in spring and summer. Weight loss was the most frequent clinical sign of 88.9% and skin sampling was the most used diagnostic test to confirm this disease 66.9%. Our study provides a general view of the situation of this disease, particularly the number of cases, and their geographical distribution in Algeria. Canine leishmaniasis (CanL) is a serious zoonosis. Strict measures must be put in place.

The use of reverse osmosis (RO) for desalination holds great promise for addressing water scarcity issues in many parts of the world. However, membrane fouling is a significant impediment in this regard, as it reduces the quality and quantity of water produced, increases energy consumption, requires cleaning, and shortens membrane life. The use of granular activated carbon (GAC) adsorption in conjunction with ultrafiltration (UF) as a pre-treatment ensures that high-quality seawater enters the desalination process free of contaminants that could harm the plant. This method increases the efficiency and longevity of the equipment, lowers maintenance costs, and produces high-quality desalinated water for a variety of applications. In this study, GAC was made from commercially available charcoal and used to remove organic compounds, heavy metals, and microbiological contaminants from seawater. A preliminary study was conducted to determine GAC’s effectiveness in removing methylene blue (MB). The removal efficiency was found to be 78 and 99% at initial MB concentrations of 50 and 10 mg/L, respectively. The isotherm modeling confirms that the adsorption process follows the Langmuir model. In addition, the kinetic study demonstrated that MB adsorption on GAC follows the pseudo-second-order model. GAC filtration removed more than 99% of COD and significantly reduced metal concentrations such as Zn, Cu, and Cd. Bacteriological analysis of seawater treated with GAC revealed a significant reduction in total and fecal coliforms, as well as fecal streptococci, indicating the efficacy of the GAC/adsorption filtration system.

The aim of the study to optimize the operating parameters on the yield, composition, time and kinetics in extraction of essential oils from different Lavandula angustifolia flowers by microwave assisted steam distillation (MSD) in comparison to conventional steam distillation (SD). A preliminary study allowed for the determination of the most influential operating factors, namely water vapor flow rate and microwave heating power. The yield obtained by MSD was comparable to that obtained by SD, while the extraction time was considerably reduced with 6 min for MSD compared to 30 min for SD. Optimization of the operating parameters was assessed using response surface methodology (RSM). The optimal treatment conditions obtained were: 8 g·min–1for the steam flow rate, 500 W for the microwave power and 6 min for the extraction time. The main compounds identified in the different lavender essential oils extracted by MSD chosen as the variables in a multivariate study. A composite centered design based on a response surface methodology was investigated for each major constituent found in the oils. The results showed that the chemical composition of the lavender essential oil was strongly influenced by the MSD operating conditions. The choice of particular operating parameters will allow for extraction of a specific compound.

The objective of this experimental work was to synthesize biofuels from used food oils by a transesterification chemical process. The influence of the parameters affecting the yield of the transesterification reaction were assessed and consequently optimized to obtain good quality biodiesel, with an optimal conversion. Their chemical composition and calorific value make biofuels good alternatives to fossil fuels. To make them compatible with engines, some transformations are required to decrease their viscosity and improve their properties. The processes and their parameters were optimized by experimental methods and the produced fuels were characterized with respect to European Norms (EN 14214). The results of the investigation showed that the best yield is obtained using a mass of CaO = 0.895 g, a temperature = 40°C and a reaction time = 68.85 h.

The main objective of this study was to demonstrate the efficiency and to optimize the operating conditions of photodegradation of paracetamol in the presence of suspended titanium dioxide catalyst in a photoreactor. An experimental design study was carried out using central composite design modelling. Optimization was applied to the tubular reactor under fixed photonic flux with radiation from two 24-watt UV-A lamps. The optimal values of the operating parameters were found to be pH of 7.288, TiO2concentration of 0.9932 g·L–1and paracetamol initial concentration of 15 mg·L–1. The paracetamol degradation rate approached 98.46% under optimal conditions. Modelling of the system led to a second-degree polynomial. Regression analysis gave an R2value of 0.977 which meant good agreement between the experimental results and the predicted values. An interaction was demonstrated between the catalyst and the operating parameters (pH, CParaand CTiO2) as well as between the model pollutant concentration and the pH had an insignificant effect on the yield compared to that of the quantity of the catalyst and the initial pollutant concentration.

AbstractThymus algeriensisBoiss. et Reut. pretreated with gamma irradiation at the doses of 0, 10, 20 and 30 kGy were submitted to hydrodistillation and the resulted essential oils were analyzed for their chemical composition by GC and GC-MS and for their antioxidant activity evaluated by inhibition of lipid peroxidation, ferric reducing antioxidant power and scavenging of radicals DPPH•and ABTS•+. On the other hand, the non volatile ethanol extracts obtained by Soxhlet, were analyzed in terms of the dosage of total phenols and flavonoids and for their antioxidant activity. Although there were no qualitative changes in the chemical composition of the essential oils of the irradiated samples, minor quantitative changes were observed for some compounds for some irradiation doses, especially for the three main components: carvacrol for all the doses in addition to p-cymene and γ-terpinene for 10 kGy and γ-terpinene for 30 kGy. The antioxidant activity of the oils was dependent on the method employed to determine such activity. Total phenolics content (149.33-236.17 mg GAE/g Extract) and flavonoids (35.74 - 52.25 mg QE/g Extract) as well as the antioxidant activities decrease for the samples irradiated at 20 and 30 kGy. Contrariwise, the irradiation at 10 kGy increases total phenolic content and antioxidant activity. The results suggest that gamma-irradiation of T. algeriensisup to 10 kGy could be used as beneficial decontamination process.

AbstractResponse surface methodology (RSM) was used for the first time to investigate the efficiency of a new process developed in our laboratory: Microwaves Steam Distillation (MSD) on the oregano essential oil extraction. The selected parameters are steam flow, microwave power and extraction time, the response is essential oil yield. According to the statistical method, a second-order polynomial function was assumed to approximate the yield. The coefficient of determination R2 (91.33%), revealed a quite agreement between experimental and predictive values. Optimal conditions were: 6 g. min-1 for steam flow, 300 W for microwave power and 8 min for time. DPPH tests showed that MSD oil was the most efficient than eugenol, SD oil and the main compounds (carvacrol and thymol), and has comparable antioxidant activity to that of BHT. In the other hand, MSD and SD oils have an insecticidal effect against Rhizopertha dominica, but SD oil was most efficient.

Les acides gras de la viande cameline étudiée ont été caractérisés par 54,6 % d’acides gras saturés (AGS), 35,0 % d’acides gras mono-insaturés (AGMI) et 10,4 % d’acides gras polyinsaturés (AGPI). Le rapport polyinsaturés/saturés a été trouvé égal à 0,25, celui des ω6/ω3 égal à 4,1. La comparaison par âge n’a montré aucun effet notable sur la teneur des AG, AGS, AGMI, AGPI, ω6 et ω3 étudiés (p>0,05). La comparaison par sexe et race a mis en évidence des effets très significatifs sur la quasi-totalité des paramètres étudiés. Ainsi, les teneurs des AG, AGS, AGMI, AGPI, ω6 et ω3 ont été trouvés significativement plus élevées chez les mâles sahraouis (p<0,05). Les femelles, aussi bien sahraouies que terguies, ont exhibé des rapports AGPI/AGS et ω6/ω3 significativement plus élevés que les mâles (p<0,05) mais aussi des teneurs assez faibles en lipides et des rapports ω6/ω3 jugés favorables. Ces résultats suggèrent des caractéristiques nutritionnelles globalement meilleures, essentiellement chez les femelles, et l’intérêt de promouvoir cette viande pour des produits à caractères nutritionnels particuliers.