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El Jaam O.,Laval University | Fliss I.,Laval University | Ben-Ounis W.,Laval University | Ben-Ounis W.,Institute of Food Technologies | And 2 more authors.
LWT - Food Science and Technology | Year: 2017

Acidity and ORP of electro-activated potassium acetate and potassium citrate with and without KCl was studied and the effect of these solutions on spores of C. sporogenes was evaluated at ambient temperature. The ORP and amount of formed acid were proportional to the intensity of the applied electric current and duration of the electro-activation process. Electro-activation at 400 mA during 60 min yielded solution with ORP values of +417.50 to +1043.33 mV and pH of 3.18–3.47. The four solutions were used to study their effect on spores of C. sporogenes PA 3679 at ambient temperature. The application of electro-activated solutions resulted in a reduction level of >7 log CFU/mL of the spores. The sporicidal effect of the electro-activated solutions was demonstrated by transmission electron microscopy analysis. The micrographs showed several damages in the spores components such as core, coat and spore cortex. © 2016 Elsevier Ltd


Juan C.,University of Valencia | Chamari K.,Tunis Private University | Oueslati S.,Tunis Private University | Oueslati S.,Center de Biotechnologie de la Technopole de Borj-Cedria | Manes J.,University of Valencia
Food Analytical Methods | Year: 2015

Validation of simple and rapid method for three Alternaria mycotoxins determination including alternariol (AOH), alternariol methyl ether (AME) and tentoxin (TEN) in strawberries is described. The extraction procedure was based on a simple liquid–liquid extraction with ethyl acetate, which provided the highest recoveries and the lowest matrix effect. Analytes were determinated by liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS). The obtained relative recoveries were higher than 63 % for the studied mycotoxins in strawberries at the limit of quantification (LQ). Good linearity (r2 > 0.993) and quantification limits (3–14 ng/g) were obtained. Repeatability, expressed as relative standard deviation, was always lower than 6 %, whereas interday precision was lower than 13 % for the developed method. The method was applied to analyse 24 strawberry samples commercialized in markets of the Valencia city (Spain). Analysed samples were only contaminated with AOH and AME. © 2015 Springer Science+Business Media New York


Manai K.,University of Science and Arts of Iran | Manai K.,Tunis el Manar University | Belkadhi K.,Tunis el Manar University | Belkadhi K.,Tunis Private University
Applied Radiation and Isotopes | Year: 2016

An integration method based on Chebyshev wavelets is presented and used to calculate the Hubbell rectangular source integral. A study of the convergence and the accuracy of the method was carried out by comparing it to previous studies. © 2016 Elsevier Ltd.


Belkadhi K.,Tunis el Manar University | Belkadhi K.,Tunis Private University | Manai K.,Tunis el Manar University | Manai K.,University of Science and Arts of Iran
Radiation Physics and Chemistry | Year: 2016

Haar wavelets numerical integration method is exposed and used for evaluating the Hubbell rectangular source integral. The method convergence is studied to get the minimum iteration number for a desired precision. Haar wavelets results are finally compared to those obtained with other integration methods. © 2016 Elsevier Ltd.


Richelle A.,Biocontrol | Ben Tahar I.,Tunis Private University | Ben Tahar I.,Unite Technologies | Hassouna M.,Unite Technologies | Bogaerts P.,Biocontrol
Bioprocess and Biosystems Engineering | Year: 2015

Inorganic nitrogen supplementation is commonly used to boost fermentation metabolism in yeast cultures. However, an excessive addition can induce an opposite effect. Hence, it is important to ensure that the ammonia supplemented to the culture leads to an improvement of the ethanol production while avoiding undesirable inhibition effects. To this end, a macroscopic model describing the influence of ammonia addition on Saccharomyces cerevisiae metabolism during bioethanol production from potato peel wastes has been developed. The model parameters are obtained by a simplified identification methodology in five steps. It is validated with experimental data and successfully predicts the dynamics of growth, substrate consumption (ammonia and fermentable sugar sources) and bioethanol production, even in cross validation. The model is used to determine the optimal quantity of supplemented ammonia required for maximizing bioethanol production from potato peel wastes in batch cultures. © 2015 Springer-Verlag Berlin Heidelberg


Amdouni A.,Tunis Private University | Castagliola P.,University of Nantes | Taleb H.,University of Carthage | Celano G.,University of Catania
European Journal of Industrial Engineering | Year: 2016

This paper proposes a new efficient method to monitor the coefficient of variation (CV) in a short production run context by means of one-sided run rules type charts. Plotting points on run rules control charts is a stochastic process modelled in this paper by using Markov chains to get their main statistical properties. Proofs concerning the computation of the truncated run length properties are given. Tables summarising the main numerical results for several combinations of in-control CV values, sample sizes and shift sizes are provided. Moreover, a comparison analysis has been performed to show that implementing one-sided run rules type charts is the best decision most of the time. Finally, an example illustrates the use of these charts on real data. © 2016 Inderscience Enterprises Ltd.


Uvalieva I.,East-Kazakhstan State Technical University | Turganbayev E.,East-Kazakhstan State Technical University | Tarifa F.,Tunis Private University
STA 2014 - 15th International Conference on Sciences and Techniques of Automatic Control and Computer Engineering | Year: 2014

The paper presents an information system for monitoring of education objects on the basis of intelligent technologies that helps to increase the effectiveness of the educational institutions. The monitoring system is based on the collection and processing of data and indicators of education using data warehousing, multidimensional databases, and technology of operational and intellectual data processing. © 2014 IEEE.


Hajji Y.,Tunis el Manar University | Bouteraa M.,Tunis el Manar University | Elcafsi A.,Tunis el Manar University | Belghith A.,Tunis el Manar University | And 2 more authors.
Renewable and Sustainable Energy Reviews | Year: 2015

In the context of climate changes becomes problematic when fossil fuel reserves are dwindling and when their prices rise sharply, the possibility of using hydrogen as an energy carrier has increasingly caught interest of both public and government policy makers in recent times due to the concerns about the possible impact of greenhouse gases and the finite nature of fossil fuel reserves. Hydrogen is much lighter than air and therefore, has very strong buoyancy that will quickly remove the gas in an unconfined situation. However, any leakage of hydrogen in confined space frequented by motor vehicles such as parking garages and tunnels poses a significant hazard. In this theme, this paper gives more information about the behavior and natural ventilation of hydrogen during an accidental leak inside a residential garage. The hydrogen cloud shape and size were predicted using FLUENT software. This study investigated the influence of building geometry and position, shape and size of openings ventilation on the formation of combustible hydrogen-air clouds. © 2015 Elsevier Ltd. All rights reserved.


PubMed | Tunis Private University and CNRS Molecular Chemistry Laboratory
Type: | Journal: Journal of chromatography. A | Year: 2014

The UV-vis photodegradation of iprodione in water was investigated with a high pressure mercury lamp photoreactor. Five photoproducts of iprodione were characterized by LC-HR-MS/MS and isotopic labeling; none of them has been reported in previous studies. Three of them result from the elimination of one or two chlorine atoms followed by hydroxy or hydrogen addition while the two others are cyclic isomers of iprodione. An ICR mass spectrometer was used for by-products identification; concentrations of photoproducts were estimated with a triple quadrupole instrument, using iprodione-D5 as an internal standard. Phototransformation mechanisms were postulated to rationalize photoproducts formation. In silico QSAR toxicity predictions were conducted with the Toxicity Estimation Software Tool (T.E.S.T.) considering oral rat LD50, mutagenicity and developmental toxicity. Low oral rat LD50 values of 350 mg/kg and 759 mg/kg were predicted for cyclic isomers of iprodione, compared to that of the parent molecule (2776 mg/kg). Toxicity estimations exhibited that all the iprodione photoproducts could be mutagenic while the parent compound is not. In vitro assays on Vibrio fischeri were achieved on both irradiated and non-irradiated aqueous solutions of iprodione and on HPLC fractions containing isolated photoproducts. Phenolic photoproducts were shown to be mainly responsible for toxicity enhancement with EC50 values of 0.3 and 0.5 ppm, for the bi- and mono-phenolic compounds issued from chlorine elimination.


Maamar M.,Unite Technologies | Naimi I.,Unite Technologies | Mkadem Y.,Tunis Private University | Souissi N.,Unite Technologies | Bellakhal N.,Unite Technologies
Journal of Advanced Oxidation Technologies | Year: 2015

In this study, electrochemical oxidation of Bromothymol blue (BTB) was studied in an aqueous medium (pH = 3) by electro-Fenton process (EFP). This chemical compound belongs to the family of sulfone phthalein, widely used for dyeing in the textile industry. EFP generates in a catalytic way hydroxyl radicals (•OH) which are powerful oxidant species (E0(•OH/H2O) = 2.8 V/NHE) used for the oxidation of organic pollutants. The kinetics of BTB degradation and the mineralization efficiency of its process are investigated through the effect of some operating parameters. The value of 300 mA as applied current, Fe2+ as a catalyst with a concentration of 0.2 mM and a temperature of 40 °C are found to be the optimum operating parameters. The reaction kinetic follows a pseudo-first order with an absolute rate constant of 3.36 x 1010 M-1s-1. The efficiency of EFP is confirmed by the decrease of the molecule concentration during the treatment until its total disappearing. The chemical oxygen demand (COD) analyses indicate after 6 h a mineralization degree of 94% for the BTB synthetic solution, 91% for the effluent provided from a small Tunisian textile industry and 41% for the wastewater provided from a medium one. The energy consumption per unit COD mass (ECCOD) of the EFP is determined for the treatment of BTB synthetic solution and for the two real effluents. Concerning the BTB synthetic solution, the energetic cost is equal to 1.02 kWh (g COD)-1 at the beginning of the electrolysis and it has decreased to reach 0.30 kWh (g COD)-1 after 6 h. For the first effluent, the energy consumption rises from 1.20 to 0.36 kWh (g COD)-1. An opposite phenomenon is observed for the second effluent. © 2015 Science & Technology Network, Inc.

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