16 research outputs found
Les différentes sortes de pédagogie
Depuis les années 1980 , le terme « didactique » a été largement utilisé pour identifier les notions relatives à l’acte éducatif dès lors qu’elles auront le trait scientifique. Un débat profondément établi pour définir, déterminer et aussi pour distinguer entre les différents termes qui décrivent l’acte pédagogique « éducation-pédagogie-didactique » منذ الثمانينيات بإمكاننا ان نلاحظ الاستعمال الواسع لمصطلح التعليمية للتعبير عن الأعمال المتعلقة بالفعل التربوي بمجرد ان تأخذ الطابع العلمي.لقد قام جدال عميق من أجل تعريف و تحديد التمييز بين التربية و البيداغوجية والتعليمية في وصف الفعل التربوي.
Aroma characterization of ripe date fruits (Phoemix dactylifera L.) from Algeria
The headspace of eight Algerian date varieties with low market value were analyzed for their aroma
compounds using solid phase micro extraction and gas chromatography combined with mass
spectrometry. In this study, 61 identified compounds were categorized in various chemical classes on
the basis of their functional groups, alcohols, esters, aldehydes, terpenoids, ketones, hydrocarbons,
and ethers. Twenty specific volatiles were found to be representative of a single variety and four shared
molecules were exclusively observed in all the studied dates. Some dates such as Bent Qbala, Litima,
and Timjouhart were statistically different from the other varieties which presented on the contrary a
significant similarity between them. In the present study, forty eight new volatile compounds were
identified which could be useful for the characterization of the Algerian date
Solid–Liquid Phase Equilibria, Molecular Interaction and Microstructural Studies on (N-(2-ethanol)-p-nitroaniline + N-(2-acetoxyethyl)-p-nitroaniline) Binary Mixtures
Differential scanning calorimetry (DSC) is used to investigate the thermal properties of N-(2-ethanol)-p-nitroaniline+N-(2-acetoxyethyl)-p-nitroaniline, and their binary systems. The experimental results demonstrate that the studied binary system presents a simple eutectic behavior and the corresponding mole fraction(xeu)ofN-(2-ethanol)p-nitroaniline at the eutectic point is 0.5486, whereas the temperature (Teu) is found to be equal to 363.6 K. The quality of the solid–liquid equilibria (SLE) data has been checked by thermodynamic consistency tests, presenting good quality factor. The SLE data have been correlated by means of Wilson, NRTL, and UNIQUAC equations. The three models describe satisfactorily the phase diagram as the root-mean-square deviations for the equilibrium temperatures vary from 1.25K to 2.07K. Nevertheless, the Wilson model provides the best correlation results. The three equations have also been used to compute excess thermodynamic functions viz. excess Gibbs energy, enthalpy and entropy. The obtained results revealed a sensitive positive deviation to ideality thus demonstrating the nature of the interactions between the compounds forming the mixture. Microstructural studies have been carried out by FTIR, XRD and optical microscopy showing weak molecular interactions for the eutectic mixture.info:eu-repo/semantics/publishedVersio
Effet de la température sur la réflectivité du silicium oxydé : détermination expérimentale de la sensibilité relative ; application à la mesure sans contact de la température à la surface d'un thyristor GTO en commutation
Temperature effect on the absolute reflectivity of oxidized is experimentally studied in the spectral range 300 nm 500 nm. spectra are measured for 25 C 225 with the precision . The largest relative variations of are observed near direct interband transition: eV. In this case, the relative sensitivity reaches the maximum value ( which is about two times higher than in the case of bare silicon. This result is used to make a temperature contactless measurement, by a technique based on reflectometry, along the gate-cathode junction on the upper face of a 1,200 volts gate turn-off thyristor operating at 400 Hz in the switching mode. The size of the optical probe is 20 micrometers, and the smallest variation that can be detected is 10 C. The measurements show a noticeable variation of heating coefficient according to the probe's position, dissipated energy at turn-off being constant (1 mJ 25 mJ). Maximum values of the junction temperature were found as high as 275 C and 350 C, according to the considered area on the chip.L'effet de la température sur la réflectivité absolue du silicium et du silicium oxydé est étudié expérimentalement dans le domaine spectral 300 nm 500 nm. Les spectres sont relevés pour 25 C 225 C avec la précision . Les variations relatives de les plus importantes sont observées au voisinage de la transition directe interbande : eV. Dans ce cas, la sensibilité relative atteint la valeur maximum (
qui est environ deux fois plus élevée que dans le cas du silicium nu. Ce résultat est mis à profit pour réaliser des mesures sans contact de la température, par réflectomètrie, le long de la jonction gâchette-cathode sur la face supérieure d'un thyristor GTO fonctionnant en commutation à 400 Hz. Le diamètre de la sonde optique est 20 micromètres, et la plus petite variation de température détectable est 10 C. Les mesures montrent que le coefficient d'échauffement varie sensiblement suivant la position de la sonde, l'énergie dissipée à l'ouverture du composant restant constante (1 mJ 25 mJ). Selon la région explorée sur la puce de silicium, on détermine des températures de jonction aussi élevées que 275 C et 350 C
Evaluation of Physicochemical Properties and Sensory Qualities of Pasta Enriched with Freeze-Dried Sweet Whey
For food industry, the production of functional pasta from non-conventional raw materials represents a challenge. This study aims to evaluate the potential of animal proteins of freeze-dried whey as a component for pasta production and its effect on the pasta qualities and consumer acceptance. Sweet whey was freeze-dried, then directly incorporated to pasta at a 20% level. Two pasta types (pasta non-enriched vs. enriched with whey powder) were manufactured following a small-scale pilot procedure, and then evaluated for their physicochemical and sensory qualities. Results of all analyses (whey, semolina and pasta) met the standards according to international legislation; however, the characteristics of enriched pasta differed. Whey addition significantly increased ash, proteins content, optimal cooking time and water uptake (P < 0.05); it significantly decreased moisture levels, colour parameters (CIE system: a* redness, b* yellowness) and the swelling index (P < 0.05). Sensory analysis revealed that overall sensory and product quality of enriched pasta was not affected by whey fortification and it was found acceptable by panelists. This study points out that whey powder could be used for the functional pasta production to increase proteins levels