Effect of limestone fines on the mechanical properties and durability of mortar made with crushed sand

This study investigate the influence of limestone fines (LF) on the mechanical properties, hydration heat and durability (acid and sulfate environments) of mortars made with crushed sand (CS) and different rate replacement of limestone fines of the CS (0%, 5%, 10%, 15%) using three types of cement, that is, ordinary Portland cement, limestone cement and pozzolanic cement. The obtained results show that the limestone fines increase the compressive strength and generate more hydration heat for all the used cements. Mortars made with blended cements, limestone or pozzolan, with 5% and 10% limestone fines, have low expansion when imerged in 5% Na2SO4 solution. In addition, when immerged in acids environment, the mortars with limestone fines exhibit negative effect at long-term durability. However, the mortar manufactured with ordinary Portland cement containing 15% of limestone fines will be strongly affected. It was found that no benefit can be gained from eliminating limestone fines fraction from the CS

Lire l’espace public pour mieux l’écrire

L’espace public constitue un puissant symptôme de la médiatisation d’une culture et d’une société : des phénomènes de communication, en tant qu’interactions, ont lieu entre les individus et les espaces publics, et leur compréhension se révèle importante pour garantir la qualité de toute intervention. Par ailleurs, l’espace public est composé de deux parties indissociables. Une entité « physique » et une entité « sensible ». Elles influencent toutes deux l’évolution de la composition urbaine et son écriture. La question principale à laquelle il faut répondre dans cet article est « Quels caractères du cadre physico-spatial et quels signes devons nous cerner et étudier pour pouvoir lire l’espace public et être ainsi, en mesure de protéger son écriture et la continuer ? ». L’apport des sciences de la communication est déterminant dans le choix d’une méthodologie, notamment pour approcher les usagers de l’espace public et les interroger. Le croisement de tous les niveaux d’analyse grâce à la systémique, dans un deuxième temps, permet de superposer les indicateurs de lisibilité dégagés à partir des analyses classiques (morphologique, fonctionnelle et historique) et les confronter à ceux qui découlent de l’analyse sémantique. Ainsi, un début de référentiel en matière d’écriture de l’espace public peut être élaboré.The public space constitutes a powerful symptom of the mediatization of a culture and a society as phenomena of communication as interactions take place between individuals and public spaces and prove to be important in guaranteeing the quality of any intervention. Moreover, the public space consists of two inseparable elements: a “physical” entity, and a “sensitive” entity, which together influence both the evolution of the urban composition and its writing. The main question this paper seeks to answer is: What aspects of the physical-spatial frame and what signs should we identify and study in order to be able to read the public space and thus be in a position to protect its writing and to take it further? The contribution of the sciences of communication is determinant in the choice of a methodology, notably in approaching users of the public space and in questioning them. At the second stage, the linking of all levels in the analysis thanks to a systemic approach allows us to superimpose the indicators of legibility generated by classic analyses (morphological, functional, or historical) and to compare these with those arising from a semantic analysis. As a result, the beginnings of a repository of the writing of the public space can be elaborated

Effect of limestone fines on the mechanical properties and durability of mortar made with crushed sand

This study investigate the influence of limestone fines (LF) on the mechanical properties, hydration heat and durability (acid and sulfate environments) of mortars made with crushed sand (CS) and different rate replacement of limestone fines of the CS (0%, 5%, 10%, 15%) using three types of cement, that is, ordinary Portland cement, limestone cement and pozzolanic cement. The obtained results show that the limestone fines increase the compressive strength and generate more hydration heat for all the used cements. Mortars made with blended cements, limestone or pozzolan, with 5% and 10% limestone fines, have low expansion when imerged in 5% Na2SO4 solution. In addition, when immerged in acids environment, the mortars with limestone fines exhibit negative effect at long-term durability. However, the mortar manufactured with ordinary Portland cement containing 15% of limestone fines will be strongly affected. It was found that no benefit can be gained from eliminating limestone fines fraction from the CS

In vivo assessment of anti-inflammatory and antioxidant activities of Phlomis crinita polyphenols

The leaves of Phlomis crinita are traditionally used in Algerian medicine for the treatment of pain and inflammatory conditions. In order to find a potential application for this native species, the anti-inflammatory and antioxidant effects were investigated on various in vivo experimental models, and the total phenolic compounds and flavonoid contents were determined. The carrageenan-induced paw edema method was used to evaluate the anti-inflammatory activity of the extract in vivo, while the in vivo antioxidant effect was assessed by estimating oxidative stress parameters (MDA, CAT, and SOD). Phytochemical screening revealed the presence of substances with high therapeutic values. In vivo anti-inflammatory studies show that plant extract has a significant and dose-dependent impact on the inhibition of edema formation. The maximum percentage inhibition value was 87.79% after 4 h at a concentration of 500 mg/kg. Moreover, the administration of the extract significantly enhanced the activities of antioxidant enzymes in the livers of mice. It significantly (p ˂ 0.05) increased CAT and SOD activities and significantly (p ˂ 0.05) decreased the MDA level activity, compared to the control inflammatory group. Our findings support that Phlomis crinita can be considered as a promising source of therapeutic bioactive compounds. DOI: http://dx.doi.org/10.5281/zenodo.786033

Ultrasound as pre-treatment for microwave drying of Myrtus communis fruits: Influence on phenolic compounds and antioxidant activity

Background: Drying constitutes the most common method of food preservation that may degrade nutrients compounds in fruits due to high temperatures and long drying times. Myrtus communis is one of the important aromatic and medicinal species, owing to these reasons, the development of new methods of drying is essential for the preservation and valorization of myrtle fruits. Aims: The aim of the present study was to investigate the effect of ultrasound as a pre-treatment (USP) at 10 min to 90 min in microwave-drying (MD) on the dehydration of myrtle Myrtus communis fruits, on phytochemical content, and on antioxidant activity. Methods: ultrasound drying as pretreatment in microwave drying, extraction yield efficiency and antioxidant activity were measured using radical scavenging assay (DPPH•) and reducing power in addition the PCA analysis was investigated to detect the relationships between variables. Results: The ultrasound pretreatment reduced notably the microwave drying time. A pretreatment of 90 min provided the most rapid drying kinetics (6 min and 5.5 min for 500 w and 700 w respectively) compared to the microwave drying alone (18 min and 11 min for 500 w and 700 w respectively). A higher phytochemical content; 219.90 ± 0.69 mg GAE/g for total phenol content (TPC) was obtained compared to those from MD and conventional drying (CD); 193.79 ± 0.99 mg GAE/g and 148.16 ± 0.95 mg GAE/g for TPC respectively. Indeed, the antioxidant activity tests revealed that ultrasound pretreatment is one of the most efficient methods to preserve the quality and the hydrogen and/or electron-donating ability of antioxidants for neutralizing DPPH radicals (98.63 %) test and reducing ferric ions to ferrous ones. Effectively, the results of PCA analysis show a higher positive correlation between antioxidant activity and flavonoids, anthocyanins, and tannins contents. Conclusions: Ultrasound pretreatment is expected to be a potential alternative to preserve fruit quality during microwave drying because it can reduce drying time at ambient temperatures while preserving natural heat-sensitive nutritive components, flavor, and color

Phenolic compounds, antioxidant and antibacterial activities of three Ericaceae from Algeria

International audienceHerbs of the Ericaceae family are commonly found in Algeria and used in traditional medicine as antiseptic, diuretic, astringent, depurative, and to treat scalds and wounds. The methanolic extracts of three species, Arbutus unedo L. (A. unedo, leaves), Erica arborea L. (E. arborea, flowered aerial parts), and Erica multiflora L. (E. multiflora, flowered aerial parts), were compared regarding their content in phenolic compounds, their antioxidant, and antibacterial activities. A. unedo harbors the highest content in total phenolics and flavonoids, followed by E. arboreaE. multiflora. The contents in total phenolics and flavonoids showed a correlation with the measured antioxidant (hydrogen-donating) activities; this was particularly the case for flavonoids content. The A. unedo extract showed antibacterial activity against all the tested strains (Staphylococcus aureus ATCC 6538, S. aureus C100459, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 9027); however, the E. arborea and E. multiflora extracts showed antibacterial activity only against Gram positive bacteria. Some polyphenols were identified in the three herbs by thin-layer chromatography and high-performance liquid chromatography coupled with diode array and mass spectrometry detection; from these, caffeic acid, p-coumaric acid, naringin, quercetin and kaempferol are reported for the first time in E. multiflora

Kinetic Modeling of Convective and Microwave Drying of Potato Peels and Their Effects on Antioxidant Content and Capacity

This study deals with drying properties and focuses on the drying kinetics of potato peels (PP) by two processes, namely convection drying (CD) at various temperatures (40, 60, 80, 100, and 120 °C) and microwave drying (MD) at different powers (200, 400, 600, and 800 W). In addition, the effectiveness of the adopted processes was evaluated in terms of antioxidant contents and antioxidant capacity. A total of 22 mathematical models were undertaken to predict the drying kinetics, and the best model was selected based on the highest R2 values and the lowest χ2 and RMSE values. The Sledz model was the more appropriate for both methods with values of 0.9995 ≤ R2 ≤ 0.9999, χ2 = 0.0000, and 0.0054 ≤ RMSE ≤ 0.0030 for CD, and the results of MD were 0.9829 ≤ R2 ≤ 0.9997, 0.0000 ≤ χ2 ≤ 0.0010, and 0.0304 ≤ RMSE ≤ 0.0053. The best drying rates (DR) of PP were assigned to a temperature of 120 °C and a power of 600 W with values of 0.05 and 0.20 kg water/kg dw min, respectively. A potential explanation is that as PP’s moisture content decreased during the drying process, there was a drop in absorption, which led to a reduction in the DR. The energy consumption of both processes was assessed, and it rose with increasing temperature or power. The microwave process reduced the drying time, consumed lower energy, and presented a higher drying efficiency at a moderate power level compared to the convection process. Furthermore, MD preserved antioxidants better compared to CD and improved the antioxidant capacity. Therefore, the proposed microwave process for drying PP is suggested for its expected use in various fields, including the food processing industries.Depto. de Producción AnimalFac. de VeterinariaTRUEpu

RP-HPLC-PDA-ESI-MS/MS screening of bioactive compounds from Degla-Beida dates: Conventional and green extraction technologies

Date fruits have vital therapeutic properties, in the way that they represent an inexhaustible source of bioactive compounds such as polyphenols. Therefore, the objective of this work was to evaluate the phytocomposition by High Performance Liquid Chromatography (RP-HPLC-PAD-ESI-MS/MS) of the optimized microwave-assisted extraction (MAE) phenolic extract by using the response surface methodology (RSM) compared to the ultrasound-assisted and conventional extractions (UAE and CE), and to test its antioxidant activity in vitro. The resulting regression model indicated that a quadratic polynomial model was best suited for the spectrophotometrically determined total phenolics. The maximum total phenolic content, TPC, (4.27±0.09 mg GAE/g DW) was obtained with a 50% (v/v) ethanol's concentration, a 700 W microwave power and an extraction time of 2.42 minutes. HPLC analysis revealed the presence of organic sugars and acids, nucleoside, carotenoids, proanthocyanidins, lignans, flavonols, flavones, saponin and sterol glucosides. The MAE phenolic extract showed 58.72±0.29% DPPH radical scavenging activity and a 1.88±0.09 mg AscAE/mL reducing power

Some Like It Fat: Comparative Ultrastructure of the Embryo in Two Demosponges of the Genus Mycale (Order Poecilosclerida) from Antarctica and the Caribbean

0000-0002-7993-1523© 2015 Riesgo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License [4.0], which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The attached file is the published version of the article

Relation between fibre distribution and post-cracking behaviour in steel fibre reinforced self-compacting concrete panels

In this research, the influence of the fibre distribution and orientation on the post-cracking behaviour of steel fibre 14 reinforced self-compacting concrete (SFRSCC) panels was studied. To perform this evaluation, SFRSCC panels 15 were cast from their centre point. For each SFRSCC panel, cylindrical specimens were extracted and notched either 16 parallel or perpendicular to the concrete flow direction, in order to evaluate the influence of fibre dispersion and 17 orientation on the tensile performance. The post-cracking behaviour was assessed by both splitting tensile tests and 18 uniaxial tensile tests. To assess the fibre density and orientation through the panels, an image analysis technique was 19 employed across cut planes on each tested specimen. It is found that the splitting tensile test overestimates the post20 cracking parameters. Specimens with notched plane parallel to the concrete flow direction show considerable higher 21 post-cracking strength than specimens with notched plane perpendicular to the flow direction.The studies reported in this paper are part of the research project LEGOUSE (QREN, project no 5387). This project is co-supported by FEDER through COMPETE programme ("Programa Operacional Factores de Competitividade"). The materials were supplied by Radmix and Maccaferri (fibres), SECIL (cement), SIKA and BASF (superplasticizers), Omya Comital (limestone filler), and Pegop (Fly ash)