Comparative study between carob and date syrups

Date and carob syrups are traditional foods produced and consumed in several countries, including Tunisia. Each syrup is characterized by its interesting nutritional and bioactive composition. Several studies have been carried out on the production and characterization of each syrup separately, but this study tends to compare the aromatic, physico-chemical, nutritional and functional properties of commercial carob and date syrups. The results showed a comparable aromatic composition whose major compounds are terpenes (carvone and menthol), a difference in color since carob syrup was characterized by a darker brown color, a nutritional composition rich in sugars and a difference in functional properties since carob syrup had greater emulsifying capacity and antioxidant activity. Thus, the characteristics of carob and date syrups encourage their use in the food industry according to the appropriate product

Contribution expérimentale au contrôle d'écoulement d'un corps épais par jets synthétiques (application à l'aérodynamique automobile)

Aujourd hui, la politique européenne incite les industriels de l automobile à concevoir des véhicules propres , ainsi des normes de plus en plus contraignantes visant notamment à réduire les émissions de gaz à effet de serre ont vu le jour. Les ingénieurs sont donc amenés à envisager des solutions innovantes basées sur le contrôle des écoulements, en particulier celui des décollements puisqu ils ont généralement des effets délétères sur les performances aérodynamiques. En effet, les phénomènes de décollement, inhérent aux corps épais, sont à l origine de l augmentation de la traînée et par conséquent de la consommation de carburant. Les travaux présentés dans ce mémoire sont dédiés au contrôle d écoulement en vue de la réduction de traînée sur un modèle générique de véhicule automobile appelé Corps de Ahmed par une combinaison d actionneur de type jets ynthétiques. Le mémoire s articule autour de deux axes principaux. Le premier a permis la caractérisation d actionneurs de type jets synthétiques, les fréquences et amplitudes optimales au regard de différents critères ont ainsi été identifiées et analysées. Le second a été consacré à étudier la réponse des structures décollés à des perturbations périodiques localisées afin de poursuivre la compréhension de la physique impliquée dans le contrôle de la traînée aérodynamique.Nowadays, the car manufacturers are forced by the european policy to follow more and more strict rules concerning the design of clean automotives, in order to reduce the gas emissions responsible for the greenhouse effect. The engineers have to consider innovative solutions based on flow control, particularly for flow separation which generally has deleterious effects on aerodynamic performance. Indeed, the separation phenomena, inherent to the bluff bodies, are at the origin of thedrag increase and consequently of the fuel consumption. The work presented in this thesis is dedicated to combinated flow separation control from simplified hatchback geometry (Ahmed body) by a synthetic jet. The thesis focuses on two main axes. The first axis has allowed the characterization of synthetic jets actuators, the frequencies and the optimal amplitudes with regard to various criteria were so identified and analyzed. The second axis was dedicated to study the separation flow structures response from local periodic disturbances in order to pursuing the physics knowledge involved in the aerodynamic drag control.VALENCIENNES-Bib. électronique (596069901) / SudocSudocFranceF

Etude des propriétés physico-chimiques et fonctionnelles du sirop de caroube

Le caroubier présente plusieurs intérêts pour toutes ses composantes, surtout pour ses fruits (gousses de caroube ou caroube). Plusieurs recherches scientifiques ont démontré que le fruit de caroube est riche en éléments nutritifs et composés phytochimiques. Ce qui explique son utilisation comme matière première pour la fabrication de divers produits, notamment le sirop de caroube. Certaines études ont été menées sur les caractéristiques physico-chimiques de ce produit, mais à notre connaissance, il n’y a pas encore des études scientifiques concernant ses propriétés fonctionnelles et son utilisation potentielle en industrie alimentaire. Donc, ce travail montre bien que le sirop de caroube possède des propriétés fonctionnelles intéressantes. Il présente une capacité émulsifiante (~80-87 %) comparable à celle de la lécithine de soja (~100 %), un émulsifiant largement utilisé dans les formulations alimentaires. Ce résultat révèle que le sirop de caroube peut être utilisé comme un émulsifiant alimentaire naturel pour la formation et la stabilité des émulsions

Contribution expérimentale au contrôle d'écoulement d'un corps épais par jets synthétiques : application à l'aérodynamique automobile

Aujourd’hui, la politique européenne incite les industriels de l’automobile à concevoir des véhicules “propres”, ainsi des normes de plus en plus contraignantes visant notamment à réduire les émissions de gaz à effet de serre ont vu le jour. Les ingénieurs sont donc amenés à envisager des solutions innovantes basées sur le contrôle des écoulements, en particulier celui des décollements puisqu’ils ont généralement des effets délétères sur les performances aérodynamiques. En effet, les phénomènes de décollement, inhérent aux corps épais, sont à l’origine de l’augmentation de la traînée et par conséquent de la consommation de carburant. Les travaux présentés dans ce mémoire sont dédiés au contrôle d’écoulement en vue de la réduction de traînée sur un modèle générique de véhicule automobile appelé “Corps de Ahmed” par une combinaison d’actionneur de type jets ynthétiques. Le mémoire s’articule autour de deux axes principaux. Le premier a permis la caractérisation d’actionneurs de type jets synthétiques, les fréquences et amplitudes optimales au regard de différents critères ont ainsi été identifiées et analysées. Le second a été consacré à étudier la réponse des structures décollés à des perturbations périodiques localisées afin de poursuivre la compréhension de la physique impliquée dans le contrôle de la traînée aérodynamique.Nowadays, the car manufacturers are forced by the european policy to follow more and more strict rules concerning the design of “clean” automotives, in order to reduce the gas emissions responsible for the greenhouse effect. The engineers have to consider innovative solutions based on flow control, particularly for flow separation which generally has deleterious effects on aerodynamic performance. Indeed, the separation phenomena, inherent to the bluff bodies, are at the origin of thedrag increase and consequently of the fuel consumption. The work presented in this thesis is dedicated to combinated flow separation control from simplified hatchback geometry (Ahmed body) by a synthetic jet. The thesis focuses on two main axes. The first axis has allowed the characterization of synthetic jets actuators, the frequencies and the optimal amplitudes with regard to various criteria were so identified and analyzed. The second axis was dedicated to study the separation flow structures response from local periodic disturbances in order to pursuing the physics knowledge involved in the aerodynamic drag control

Comparative study between carob and date syrups

Date and carob syrups are traditional foods produced and consumed in several countries, including Tunisia. Each syrup is characterized by its interesting nutritional and bioactive composition. Several studies have been carried out on the production and characterization of each syrup separately, but this study tends to compare the aromatic, physico-chemical, nutritional and functional properties of commercial carob and date syrups. The results showed a comparable aromatic composition whose major compounds are terpenes (carvone and menthol), a difference in color since carob syrup was characterized by a darker brown color, a nutritional composition rich in sugars and a difference in functional properties since carob syrup had greater emulsifying capacity and antioxidant activity. Thus, the characteristics of carob and date syrups encourage their use in the food industry according to the appropriate product

Etude des propriétés physico-chimiques et fonctionnelles du sirop de caroube

Le caroubier présente plusieurs intérêts pour toutes ses composantes, surtout pour ses fruits (gousses de caroube ou caroube). Plusieurs recherches scientifiques ont démontré que le fruit de caroube est riche en éléments nutritifs et composés phytochimiques. Ce qui explique son utilisation comme matière première pour la fabrication de divers produits, notamment le sirop de caroube. Certaines études ont été menées sur les caractéristiques physico-chimiques de ce produit, mais à notre connaissance, il n’y a pas encore des études scientifiques concernant ses propriétés fonctionnelles et son utilisation potentielle en industrie alimentaire. Donc, ce travail montre bien que le sirop de caroube possède des propriétés fonctionnelles intéressantes. Il présente une capacité émulsifiante (~80-87 %) comparable à celle de la lécithine de soja (~100 %), un émulsifiant largement utilisé dans les formulations alimentaires. Ce résultat révèle que le sirop de caroube peut être utilisé comme un émulsifiant alimentaire naturel pour la formation et la stabilité des émulsions

New testing approach using near electromagnetic field probing intending to upgrade in-circuit testing of high density PCBAs

International audienceWith the density increase of today's printed circuit board assemblies (PCBA), the electronic test methods reached their limits, in the same time the requirements of high reliability and robustness are greater. Original equipment manufacturers are obliged to reduce the number of physical test points and to find better-adapted test methods. Current test methods must be rethought to include a large panel of physical phenomena that can be used to detect electrical defects of components, absence, wrong value, and shorts at component level on the board under test (BUT). We will present the possibility of using electromagnetic signature to diagnose faulty components contactlessly. The technique consists in using small diameter near electromagnetic field probes, which detect the field distribution over powered sensitive components. A giant magnetoresistance (GMR) sensor was used as well to detect variations in low frequency components. The loading of the BUT is specifically chosen to enhance the sensitivity of the EM measurements. Reference EM signatures are extracted from a fault-free circuit, which will be compared to those extracted from a sample PCBA in which we introduced a component level defect by removing or changing the value of critical components. As a result, we will show that the amplitude of a specific harmonic acts as a sensing parameter, which is accurately related to the variation of the component value

Upgrading In-Circuit Test of high density PCBAs using electromagnetic measurement and Principal Component Analysis

International audienceWith the density increase of today’s printed circuit board assemblies (PCBA), electronic test methods such as in-circuit test (ICT) reached their limits. In the same time the requirements of high reliability and robustness are greater. Original equipment manufacturers are obliged to reduce the number of physical test points and to find better-adapted test methods to keep adequate test coverage. Current test methods must be rethought to include a large panel of physical phenomena that can be used to detect- electrical defects, absence, wrong value of components, absence and shorts without using test points on the board under test (BUT). In this paper, a test set-up based on the measurement of electromagnetic signature to diagnose faulty components contactlessly is presented. The technique consists in using magnetic field probes, which detect the field distribution over powered sensitive components. To evaluate the relevance of the method, reference EM signatures are extracted from fault-free circuits, which are compared to those extracted from a sample PCBA in which we introduced a component level defect by removing or changing the value of critical components. For more robust detection of multiple defect scenarios, the principal component analysis (PCA) method is used as an outlier detection algorithm

Detecting PCB Assembly defects using infrared thermal signatures

International audienceA Printed Circuit Board assembly (PCBA) testing approach using infrared thermal signatures is presented. The concept of thermal signature for PCBAs is introduced. Based on this concept, the testing method is able to:-detect assembly defects such as presence, polarity, value and solder (shorts and opens) and in some cases component health state-classify the components mounted on the PCB into a number of classes (e.g.-fault free(reliable), functional (less reliable), faulty). According to the thermal signature of each component on the PCBA, PCBAs can be also classified in the same number of classes. In this article a special focus is put on capacitor defects especially capacitor value defects. Therefore, they will be the main components tested. The fault detection indicator used in this proof of concept is a statistical mean squared error measure (MSE)

Potential of Photorhabdus temperata K122 bioinsecticide in protecting wheat flour against Ephestia kuehniella

The present study reports investigations on the insecticidal activity of the entomopathogenic bacterium Photorhabdus temperata K122 against the Mediterranean flour moth Ephestia kuehniella. Cultured in the optimized medium, P. temperata K122 cells aged 32 h exhibited 51% growth inhibition at a concentration of 9 × 108 cells/ml. However, culture must be prolonged up to 48 h incubation in the proteose peptone medium to reach only 28.6% inhibition. At the same concentration, no adult emergence was observed in the case of larvae feeding on wheat flour treated with the whole culture of P. temperata K122 after physical lysis. Interestingly, P. temperata K122 cells in the viable but non culturable (VBNC) state retained the same toxicity level as the culturable cells. At a high concentration of 12 × 108 cells/ml, 100% mortality of E. kuehniella larvae could be reached. Insect mortality is due to toxaemia as confirmed by the absence of Variants small colony (Vsm) or P. temperata colonies in E. kuehniella tissue. The investigation of the histopathological effect of P. temperata toxins on the gut of infected E. kuehniella larvae showed destruction of the gut epithelium, appearance of large cavities and cellular disintegration.Ministere de l'Enseignement Superieur et de la Recherche Scientifiqu