Letteratura scientifica selezionata sul tema "Lentille liquide"

Une goutte d'eau déposée à la surface d'un bain d'huile de tournesol forme une lentille liquide flottante. Une goutte d'alcool, au contraire, s'étale à la surface de l'huile. Un mélange d'eau et d'alcool produit un spectaculaire phénomène d'étalement et de fragmentation spontanée. Si la goutte contient suffisamment d'alcool, elle donne naissance en quelques secondes à une myriade de gouttelettes dont la taille dépend fortement de la composition initiale. La combinaison de l'hydrodynamique, du mouillage et de l'évaporation est à l'origine de cette instabilité originale.

The health-promoting effects of lentil seeds due to phenolic compounds and other antioxidants make lentils a potential source of functional food or feed ingredients. The objective of this study was to evaluate the effects of genotype and growing environment on the phytochemical contents and antioxidant activities such as ABTS (2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid), DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric reducing antioxidant power) assays of soluble extracts from five lentil cultivars grown in ten diverse locations over a 2-year experimental period. Total phenolic content (TPC), total flavonoid content (TFC), total proanthocyanidin content (TPAC), total hydrolyzed tannin content (TNC), tocopherols and carotenoids were investigated. The major proanthocyanidins and individual polyphenols were quantified by high-performance liquid chromatography. Our results indicated that flavanols were the main phenolic compounds in hydrophilic extracts, followed by phenolic acids. Concerning lipophilic extracts, tocopherols and carotenoids were the main components, with γ-tocopherol and lutein being the predominant isomers, respectively. In general, both genetic and environmental effects had a strong impact on all bioactive components tested. Greater variation due to environmental effects was found for phenolic compounds (TPC, TFC and TPAC) and antioxidant activities; however, tocopherols and carotenoids revealed a high genotypic dependence. The principal component analysis highlighted the genotypes with higher content of antioxidants and stability across environments. The red lentil population “03-24L” was characterized as a promising genetic material due to its high phenolic contents and antioxidant capacity values across environments and is suggested for further investigation. In conclusion, multi-environmental trials are essential for a better understanding of the genotypic and environmental effect on phytochemical profiles of lentils and provide important information for breeding or cultivating lentil varieties of high-bioactive value.

Legumes processing involves large amounts of water to remove anti-nutrients, reduce uncomfortable effects, and improve organoleptic characteristics. This procedure generates waste and high levels of environmental pollution. This work aims to evaluate the galacto-oligosaccharide (GOS) and general carbohydrate composition of legume wastewaters and assess their potential for growing lactic acid bacteria. Legume wastewater extracts were produced by soaking and/or cooking the dry seeds of chickpeas and lentils in distilled water and analysed using high-performance liquid chromatography with refractive index detection. GOS were present in all extracts, which was also confirmed by Fourier transform infrared spectroscopy (FTIR). C-BW extract, produced by cooking chickpeas without soaking, provided the highest extraction yield of 3% (g/100 g dry seeds). Lentil extracts were the richest source of GOS with degree of polymerization ≥ 5 (0.4%). Lactiplantibacillus plantarum CIDCA 83114 was able to grow in de Man, Rogosa, and Sharpe (MRS) broth prepared by replacing the glucose naturally present in the medium with chickpeas’ and lentils’ extracts. Bacteria were able to consume the mono and disaccharides present in the media with extracts, as demonstrated by HPLC and FTIR. These results provide support for the revalorisation of chickpeas’ and lentils’ wastewater, being also a sustainable way to purify GOS by removing mono and disaccharides from the mixtures.

Egg white is the most commonly used foaming agent in various aerated foods. Malaysia has been experiencing an egg crisis due to lower production and increased egg consumption rates since the COVID-19 restrictions were lifted. Thus, finding an alternative functional ingredient to address the egg shortage is essential. Liquids discarded from commercially plant-based canned foods have the potential to replace eggs in food products as an alternative foaming agent. Therefore, this study aims to investigate the physicochemical and sensory properties of bahulu and chocolate mousse using canned liquids of green peas (pulses N and P), lentils (pulse R), chickpeas (pulse X), button mushrooms (vegetable A), and straw mushrooms (Vegetable D). Canned liquids were incorporated into bahulu and mousse formulations to replace egg whites. The developed bahulu and mousse were baked for 25 min at 180 °C and chilled for 3 hours at 4 °C, respectively. The texture profile of bahulu and the viscosity properties of the chocolate mousse were determined in this study. Furthermore, the research examines the proximate analysis and sensory acceptance of both products. According to the findings, bahulu A, produced from canned vegetable liquids, had the lowest hardness, springiness, and chewiness (p < 0.05) levels. In contrast, canned pulse liquid, which was used in bahulu N, produced comparable hardness, fracturability, adhesiveness, springiness, cohesiveness, and chewiness with the control sample (p > 0.05). Moreover, the viscosity values of mousses A (2238.33 ± 2.89 cP) and D (2778.33 ± 2.89 cP) were lower than the control mousse (8005.00 ± 0.00 cP) (p < 0.05). Bahulu and mousse contain 6.58–6.83% and 1.52–1.90% of protein, respectively. The protein content of canned pulse liquid products was higher than that of canned vegetable liquids (p < 0.05). The lowest taste acceptance was observed in samples Bahulu N and P as well as mousses N and P (p < 0.05). This outcome could be due to the saltiness derived from the canned green pea liquid. The appearance, odor, and overall acceptability of the bahulu and mousse were comparable to the control samples and well-accepted by the panelists (p > 0.05). The findings demonstrate that canned pulse liquids (green peas, lentils, and chickpeas) can potentially mimic egg white in the development of bahulu and chocolate mousse.

Lentil (Lens culinaris) is an important crop of sustainable agriculture system having good nutritional value. Liquid biofertiliser formulations are known to have better result at field level. A field experiment was conducted in the gangetic alluvial soil belt of West Bengal to study the performance of lentil cv WBL 77 (Moitree) at farmer’s field in Krishnaganj block, Nadia, WB in the rabi season 2020-21. The experiment was conducted in randomised block design having ten treatments replicated thrice. Carrier and liquid based formulations of rhizobium and phosphorus solubilising biofertilisers were used. The results revealed that growth and yield parameters responded positively when lentil were grown with different combinations of biofertilizer and inorganic fertilizers. Recommended dose of fertilizers (RDF) + liquid based rhizobium and PSB and was found to be better in respect to growth, nodulation and yield attributes. However, was statistically at par with treatment RDF + Carrier based Rhizobium & PSB. Plots where 75% RDF + liquid or carrier based biofertilisers were applied were observed to be at par with treatments where RDF and any one biofertilier were applied. Based on the study, we may infer that liquid biofertiliser formulations can have better effect on lentil growth, nodulation and yield.

In June 2008, lentil plants (Lens culinaris Medik. cv. Crimson) in a field in Kendrick, ID exhibited symptoms including stunting, leaf chlorosis, reddening of abaxial leaf surfaces, root browning, and necrosis. Roots were surface sterilized, plated on water agar, and pure cultures were obtained through hyphal tips. DNA was extracted from mycelia and amplified with PCR primers that produced a 1,332-bp fragment specific for Aphanomyces euteiches Drechs (4). DNA of A. euteiches isolated from pea (Pisum sativum L.) was used as a positive control for PCR. A PCR product of the expected size was amplified from the positive control and also from a single isolate obtained from symptomatic lentils. Mycelial mats of the isolate (No. 823) were incubated overnight in a dilute mineral salt solution (1), a process that routinely produced 350,000 zoospores/ml, which were used to screen 33 advanced lentil breeding lines and three lentil cultivars (Eston, Crimson, and Pardina). Plants were grown in greenhouse flats containing perlite. At the time of planting, all flats were inoculated with a liquid suspension of Rhizobium leguminosarum bv. viceae. One week after emergence, all seedlings were inoculated with 20,000 or 5,000 zoospores of A. euteiches isolate 823. Plants were scored 14 days after inoculation using a 1 (no discoloration of roots) to 5 (dead seedling) disease severity index (DSI) commonly used to evaluate disease reaction to A. euteiches in pea (3). For each inoculum level, six plants of each lentil genotype were scored for disease reaction and the experiments were repeated once. A pooled analysis of both replications indicated that all entries were at least moderately susceptible to A. euteiches (mean DSI ≥3) at both inoculum levels, and the majority was highly susceptible (DSI ≥4). Oospores ~20 μm in diameter were observed in lentil roots 14 days after inoculation. In addition, five plants each of 73 NPGS PI accessions and four lentil cultivars (Eston, Crimson, Pardina, and Riveland) were inoculated with 250 zoospores per plant and scored for disease reaction. These experiments were repeated twice. Significant differences in DSI were observed among entries. The grand mean DSI of all entries was 3.56. The mean DSI of entries based on a pooled analysis of three replications ranged from 2.67 (Riveland) to 4.0 (PI 472561). All plants for each replication were bulked and dried in an oven, as were five noninoculated plants for each entry, and weighed. The average percent weight of inoculated plants relative to that of noninoculated plants for all 77 entries was 32.7% and the correlation between this percentage and DSI was –0.25 (P = 0.03). The results suggest that resistance to A. euteiches is lacking in the lentil genotypes examined and that plant biomass is reduced by the pathogen. Moussart et al. (2) recently demonstrated that a French pea isolate of A. euteiches caused severe disease among a set of 28 lentil genotypes. We detected A. euteiches in a field in which peas were recently grown and this isolate likely originated from peas. Additional lentil fields in Washington and Idaho will be surveyed for the presence of A. euteiches. Preliminary lentil breeding lines and additional accessions will be screened for tolerance to A. euteiches in the greenhouse and field. References: (1) L. M. Carman et al. Phytopathology 49:535, 1959. (2) A. Moussart et al. Eur. J. Plant Pathol. 122:321, 2008. (3) A. Rao et al. Plant Dis. 79:128, 1995. (4) G. J. Vandemark et al. Phytopathology 90:1137, 2000.

In the last decade, various foods have been reformulated with plant protein ingredients to enhance plant-based food intake in our diet. Pulses are in the forefront as protein-rich sources to aid in providing sufficient daily protein intake and may be used as binders to reduce meat protein in product formulations. Pulses are seen as clean-label ingredients that bring benefits to meat products beyond protein content. Pulse flours may need pre-treatments because their endogenous bioactive components may not always be beneficial to meat products. Infrared (IR) treatment is a highly energy-efficient and environmentally friendly method of heating foods, creating diversity in plant-based ingredient functionality. This review discusses using IR-heating technology to modify the properties of pulses and their usefulness in comminuted meat products, with a major emphasis on lentils. IR heating enhances liquid-binding and emulsifying properties, inactivates oxidative enzymes, reduces antinutritional factors, and protects antioxidative properties of pulses. Meat products benefit from IR-treated pulse ingredients, showing improvements in product yields, oxidative stability, and nutrient availability while maintaining desired texture. IR-treated lentil-based ingredients, in particular, also enhance the raw color stability of beef burgers. Therefore, developing pulse-enriched meat products will be a viable approach toward the sustainable production of meat products.

Tap water, demineralized water and liquid fertilizer have been activated using an atmospheric pressure plasma jet (APPJ) to investigate their benefits for the germination rate and stem elongation rate of lentils from Puy-en-Velay (France).

This paper aims to present a mathematical model, based on the thermodynamics of irreversible processes to describe both the heat and mass transfer (liquid and vapor) during the drying of bodies with oblate spheroidal shape. The model was applied to describe drying of lentil grain, considering variables transport coefficients and convective boundary conditions at the surface of the solid. All equations were presented in oblate spheroidal coordinates and numerically solved by using the finite-volume method. Results of the average moisture content, average temperature, liquid flux, vapor flux, and moisture content and temperature distributions inside a lentil kernel during drying process (T=40 oC, RH=50% and v=0.3 m/s) were presented and analyzed.

L’imagerie interférométrique de particules (IIP) en défaut de mise au point est une technique de granulométrie optique permettant de déterminer la forme et la taille de particules micrométriques : 20 µm − 2 000 µm. Elles peuvent être de nature différentes, par exemple, des cristaux de glace en suspension dans l’atmosphère, des cendres volcaniques, des nuages de grains de sable ou encore des particules de charbon disséminées autour de centrales thermiques. Les exemples précédents ont tous un point commun, ce sont des particules rugueuses, de formes irrégulières et les résultats de ces travaux de thèse s’appuient sur ces caractéristiques. L’acquisition d’images avec cette technique repose sur un principe de fonctionnement simple. Une particule rugueuse est illuminée avec un laser ; celle-ci diffuse une partie du rayonnement incident dans toutes les directions due aux aspérités à sa surface. Ces aspérités créent des sources secondaires du rayonnement incident. Un système d’imagerie en défaut de mise au point, enregistre les images des interférences issues de ces sources secondaires. Le développement et l’amélioration des programmes permettant de reconstruire la forme de la particule à partir de son image interférométrique est réalisé avec un banc expérimental équipé d’une matrice de micro-miroirs (DMD). La particule est "programmée" sur le DMD. Les micro-miroirs qui simulent les sources secondaires de la particule réfléchissent une partie du faisceau incident en direction du système d’imagerie. Ces travaux de thèse se concentrent d’une part sur la création d’un réseau de neurones permettant de classer la forme d’une particule à partir de son image interférométrique. Ce réseau de neurones a montré une reconnaissance dans 100% des cas. D’autre part, l’élaboration d’un autre réseau de neurones permettant de reconstruire l’enveloppe de particules irrégulières à partir de leurs images expérimentales a montré une très bonne qualité de reconstruction entre les formes programmées et les formes reconstruites. Dans les deux cas, des bases de données constituées de plusieurs milliers d’images expérimentales ont été acquises avec un montage expérimental équipé d’une matrice de micro-miroirs pour "simuler" les particules rugueuses. De plus, dans le cadre de cette technique, deux travaux supplémentaires ont été effectués : (i) d’abord une première méthode de correction de l’aberration sphérique, par passage de la base cartésienne à la base polaire, et une seconde de simulation de l’aberration sphérique en IIP, par décomposition du terme de phase en fonction gaussiènnes ; et (ii) la réalisation d’un système d’imagerie interférométrique adaptatif à base de lentille liquide a été mis au point permettant de réduire le recouvrement des interférogrammes par réglage instantané de la défocalisation du système d’imagerie
Out-of-focus interferometric particle imaging (IPI) is an optical particle sizing technique used to determine the shape and size of micrometric particles: 20 µm − 2,000 µm. They can be of different natures, for example, ice crystals suspended in the atmosphere, volcanic ash, clouds of sand grains or coal particles scattered around thermal power plants. The previous examples all have one thing in common, they are rough particles, with irregular shapes and the results of this thesis work are based on these characteristics. Image acquisition with this technique is based on a simple operating principle. A rough particle is illuminated with a laser; it diffuses part of the incident radiation in all directions due to the asperities on its surface. These asperities create secondary sources of the incident radiation. An out-of-focus imaging system records interference images from these secondary sources. The development and improvement of programs to reconstruct the shape of the particle from its interferometric image is carried out with an experimental bench equipped with a micro-mirror matrix (DMD). The particle is "programmed" on the DMD. The micro-mirrors that simulate the secondary sources of the particle reflect part of the incident beam towards the imaging system. This thesis work focuses on the one hand on the creation of a neural network to classify the shape of a particle from its interferometric image. This neural network has shown recognition in 100% of cases. On the other hand, the development of another neural network to reconstruct the envelope of irregular particles from their experimental images has shown very good reconstruction quality between the programmed shapes and the reconstructed shapes. In both cases, databases consisting of several thousand experimental images were acquired with an experimental setup equipped with a micro-mirror matrix to "simulate" rough particles. In addition, within the framework of this technique, two additional works were carried out: (i) first a first method of correction of spherical aberration, by passage from the Cartesian basis to the polar basis, and a second of simulation of spherical aberration in IPI, by decomposition of the phase term into Gaussian functions; and (ii) the realization of an adaptive interferometric imaging system based on a liquid lens was developed to reduce the overlap of interferograms by instantaneous adjustment of the defocus of the imaging system

Simulation numérique de l'écoulement laminaire bidimensionnel créé par un fil chaud placé sous une surface libre. Le code de calcul inclut les convections naturelle et de Marangoni, les transferts de chaleur à l’interface ainsi que la viscosité interfaciale. Analyse linéaire de stabilité dans le cas d'une couche liquide horizontale d'extension infinie, limitée par une paroi rigide et une surface libre. Modélisation

La structure moléculaire d'un cristal liquide cholestérique (CLC) est hélicoïdale et donne lieu à des propriétés optiques remarquables comme la réflexion sélective de la lumière. La structure cholestérique soulève des questions fondamentales comme la relation entre chiralités moléculaire et mésoscopique, et son impact sur les propriétés optiques. Elle est omniprésente en biologie (organisation de la chitine, de la cellulose, du collagène ou de la chromatine). Elle est aussi utilisée en technologie : en cosmétologie, dans les afficheurs nématiques super-torsadés, les écrans réflecteurs, les capteurs de température ou pression, les matériaux pour les applications photoniques en général. Le but du présent travail est de décrire et comprendre l'interaction de la lumière avec différents types de structures hélicoïdales non-monotones élaborées dans cette thèse - films cholestériques synthétiques (monocomposant ou hybrides i.e. dopés en nanoparticules d'or) - ou dans un matériau biologique (carapace du scarabée Chrysina gloriosa). Différentes techniques de caractérisation optique ont été utilisées suivant le matériau à étudier et les questions posées. La partie principale du manuscrit est dédiée aux microlentilles et micro-miroirs cholestériques. Nous avons étudié la texture polygonale cholestérique et mis en évidence qu'elle se comporte comme un réseau de microlentilles chirales à l'aide de la microscopie confocale couplée à la spectrophotométrie. Ces microlentilles organiques, élaborées en deux étapes par auto-assemblage, ont la particularité d'être sélectives en longueur d'onde. Nous avons ensuite montré que la texture polygonale de la carapace de Chrysina gloriosa, analogue biologique, est un réseau de micro-miroirs sphériques et de microlentilles convergentes. La seconde partie du manuscrit est consacrée à l'élaboration de matériaux hybrides CLC et nanoparticules d'or et à l'étude de leurs propriétés optiques. Les propriétés optiques de ces nanocomposites ont été sondées à l'aide de différentes techniques (résonance plasmon, spectrométrie Raman etc)
The molecular structure of a cholesteric liquid crystal (CLC) is helical and gives rise to outstanding optical properties like the selective reflection of the light. Cholesteric structure raises fundamental questions such as the relationship between molecular chirality and mesoscopic chirality, and its impact on optical properties. It is omnipresent in biology (organisation of chitin, cellulose, collagen or chromatin). It is also used in technology: cosmetology, super-twisted nematic displays, reflective screens, temperature or pressure sensors, materials for photonic applications in general. The purpose of this work is to describe and understand the interaction of light with different types of non-monotonous helical structures elaborated in this thesis - synthetic cholesteric films (single-component or hybrid i.e. doped with gold nanoparticles) - or in a biological material (Chrysina gloriosa beetle). Several optical characterisation techniques have been used, depending on the sample to study and the questions which are rised. The main part of the manuscript is dedicated to cholesteric microlenses and micro-mirrors. We studied the cholesteric polygonal texture and highlighted that it acts as a chiral microlens array by using confocal microscopy coupled to spectrophotometry. These organic microlenses, developed in a two-step process by self-assembly, have the specificity of being wavelength-selective. We then showed that the polygonal texture of Chrysina gloriosa, as a biological analogous, is an array of spherical micro-mirrors and convergent microlenses. The second part of the manuscript is devoted to the elaboration of hybrid materials composed of CLC and gold nanoparticules and the study of their optical properties. Optical properties of these nanocomposites were probed using various techniques (plasmon resonance, Raman spectroscopy etc)

Ce travail est consacré à l'étude expérimentale des effets de la pression de radiation d'une onde laser continue sur une interface liquide. Les propriétés particulières du ménisque séparant deux phases liquides en coexistence au voisinage de leur point critique de démixtion nous ont permis de visualiser directement des déformations stationnaires d'interface de taille micrométrique. Au stade linéaire, i.e pour des intensités laser modérées, une loi d'échelle exprimant la hauteur des déformations a été validée, ceci pour les deux sens de propagation du faisceau relativement à l'interface. Pour des excitations laser plus élevées, une brisure de symétrie vis à vis du sens de propagation a été mise en évidence. On observe en effet la formation de doigts de grand rapport d'aspect, ou la brisure de l'interface suite à une instabilité optohydrodynamique, suivant que le faisceau se propage du milieu le moins réfringent au milieu le plus réfringent, ou inversement. Ces caractéristiques ont été exploitées pour créer et stabiliser sous champ laser des ponts liquides de rapports d'aspect bien supérieurs à la limite de l'instabilité de Rayleigh-Plateau des colonnes liquides. Les déformations thermocapillaires, engendrées par la faible élévation de température induite par le faisceau laser, ont également été caractérisées, afin de les distinguer sans ambiguité des déformations engendrées par la pression de radiation seule.