22 research outputs found
Quick analysis of rubber,lipids and other components of the biomass of Parthenium argentatum by NIRS and fractionating process.
No full textDosage du polyisoprène et des résines de la biomasse de guayule (Parthenium argentatum) par spectroscopie proche infrarouge (SPIR) Méthodes d'extraction par solvant de référence Un protocole basé sur l'extraction accélérée (ASE) avec l'acétone (EA) (résine) puis l'hexane (EH) (polyisoprène, PI) a été sélectionné et optimisé (rendement maximal; adapté à l'analyse de séries) ; quantification d'abord basée sur le poids de l'extrait (gravimétrie). L'EH est maximal à 120°C après étapes avec l'acétone à 40°C (plan d'expérience). La contamination croisée a été confirmée par SEC et FTIR (5 à 29%), conduisant à une deuxième méthode basée sur résine et PI et non plus sur EA et EH, incluant le PI de faible masse molaire (Mw) de l'EA. Ces 2 méthodes de référence ont servi à calibrer la SPIR (chimiométrie/PLS, coeff. beta) afin de relier signature spectrale, PI, résine. ASE-SPIR, couplés ici pour la première fois, ont été plus performants (R² 0.96; 0.98; RPD 4.8; 4.6; EA et EH resp.) que les méthodes de la littérature, grâce aux 215 échantillons représentatifs (génotypes, saison, âge du guayule, climat). La méthode tenant compte de la contamination est moins performante (erreur exp. due aux analyses SEC et FTIR; variation de composition des résines). Ayant montré la dégradation du PI au cours de l'extraction, un autre protocole a été étudié (biomasse humide, un solvant, une seule étape, 20°C) afin d'accéder au Mw «natif », donnant 2.106 g au lieu de 6.105 avec la biomasse séchée; il faut donc être prudent face aux Mw de guayule de la littérature. Ce travail montre la nécessité de tenir compte de la complexité de la biomasse de guayule (échelle cellulaire/PI vacuolaire, résine des canaux; moléculaire/instabilité chimique) lors de l'extraction du PI pour l'analyse structurale. Ces méthodes analytiques ont contribué à produire des prototypes (gant non allergisant, pneu) à haut Mw et à l'acclimatation en Europe dans le cadre du projet EU-Pearls.Measurement of resin and polyisoprene in Parthenium argentatum (guayule) biomass using near infrared spectroscopy (NIRS) -Associated solvent-based reference methods .A protocol based on sequential extraction with acetone (resin) and hexane (polyisoprene, PI) with accelerated solvent extraction (ASE) was optimized and selected (maximized yield; adapted to large series) instead of Soxhlet and homogenizer. Quantification was first based on extract weight (gravimetry). Hexane extract was maximized at 120°C, after acetone steps at 40°C, through an experimental design. Cross contamination was confirmed and quantified (5 to 29%; SEC and FTIR). This gave a second method based on resin and PI, instead of crude extracts, accounting for low average molar mass PI (Mw) extracted by acetone instead of hexane. Both reference methods were used for calibrating NIRS applied to powdered biomass, with chemometric tools (PLS loadings, beta coefficients) to interpret spectral bands vs PI-resin relationship. ASE, not used before as reference, is highly reliable, and calibration with gravimetry (R² 0.96; 0.98; RPD 4.8; 4.6; for acetone and hexane extract) better than published data, thanks to the 215 samples covering genotypes, harvest date, plant age, climate. The method using cross contamination was less efficient because of higher experimental error induced by additional SEC and FTIR, and change in resin composition. Having set NIRS methods, a new protocol (single solvent THF, minimized processing, 20°C, fresh biomass) was designed to avoid degradation, yielding PI extracts with Mw above 2.106g/mole, closer to in vivo structure (6.105 when using dried guayule); caution to sample preparation in literature dealing with guayule PI structure. This calls for considering the complex structure of guayule biomass (PI in cells; resin in ducts; chemical instability) when extracting PI. These methods allowed producing high PI Mw glove and tire prototypes and domesticating this new crop in Europe within the EU-Pearls project
Dosage du polyisoprène et des résines de la biomasse de guayule (Parthenium argentatum) par spectroscopie proche infrarouge (SPIR) Méthodes d'extraction par solvant de référence
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Dosage du polyisoprène et des résines de la biomasse de guayule (Parthenium argentatum) par spectroscopie proche infrarouge (SPIR) (méthodes d'extraction par solvant de référence)
Get PDFDosage du polyisoprène et des résines de la biomasse de guayule (Parthenium argentatum) par spectroscopie proche infrarouge (SPIR) Méthodes d'extraction par solvant de référence Un protocole basé sur l'extraction accélérée (ASE) avec l'acétone (EA) (résine) puis l'hexane (EH) (polyisoprène, PI) a été sélectionné et optimisé (rendement maximal; adapté à l'analyse de séries) ; quantification d'abord basée sur le poids de l'extrait (gravimétrie). L'EH est maximal à 120C après étapes avec l'acétone à 40C (plan d'expérience). La contamination croisée a été confirmée par SEC et FTIR (5 à 29%), conduisant à une deuxième méthode basée sur résine et PI et non plus sur EA et EH, incluant le PI de faible masse molaire (Mw) de l'EA. Ces 2 méthodes de référence ont servi à calibrer la SPIR (chimiométrie/PLS, coeff. beta) afin de relier signature spectrale, PI, résine. ASE-SPIR, couplés ici pour la première fois, ont été plus performants (R 0.96; 0.98; RPD 4.8; 4.6; EA et EH resp.) que les méthodes de la littérature, grâce aux 215 échantillons représentatifs (génotypes, saison, âge du guayule, climat). La méthode tenant compte de la contamination est moins performante (erreur exp. due aux analyses SEC et FTIR; variation de composition des résines). Ayant montré la dégradation du PI au cours de l'extraction, un autre protocole a été étudié (biomasse humide, un solvant, une seule étape, 20C) afin d'accéder au Mw natif , donnant 2.106 g au lieu de 6.105 avec la biomasse séchée; il faut donc être prudent face aux Mw de guayule de la littérature. Ce travail montre la nécessité de tenir compte de la complexité de la biomasse de guayule (échelle cellulaire/PI vacuolaire, résine des canaux; moléculaire/instabilité chimique) lors de l'extraction du PI pour l'analyse structurale. Ces méthodes analytiques ont contribué à produire des prototypes (gant non allergisant, pneu) à haut Mw et à l'acclimatation en Europe dans le cadre du projet EU-Pearls.Measurement of resin and polyisoprene in Parthenium argentatum (guayule) biomass using near infrared spectroscopy (NIRS) -Associated solvent-based reference methods .A protocol based on sequential extraction with acetone (resin) and hexane (polyisoprene, PI) with accelerated solvent extraction (ASE) was optimized and selected (maximized yield; adapted to large series) instead of Soxhlet and homogenizer. Quantification was first based on extract weight (gravimetry). Hexane extract was maximized at 120C, after acetone steps at 40C, through an experimental design. Cross contamination was confirmed and quantified (5 to 29%; SEC and FTIR). This gave a second method based on resin and PI, instead of crude extracts, accounting for low average molar mass PI (Mw) extracted by acetone instead of hexane. Both reference methods were used for calibrating NIRS applied to powdered biomass, with chemometric tools (PLS loadings, beta coefficients) to interpret spectral bands vs PI-resin relationship. ASE, not used before as reference, is highly reliable, and calibration with gravimetry (R 0.96; 0.98; RPD 4.8; 4.6; for acetone and hexane extract) better than published data, thanks to the 215 samples covering genotypes, harvest date, plant age, climate. The method using cross contamination was less efficient because of higher experimental error induced by additional SEC and FTIR, and change in resin composition. Having set NIRS methods, a new protocol (single solvent THF, minimized processing, 20C, fresh biomass) was designed to avoid degradation, yielding PI extracts with Mw above 2.106g/mole, closer to in vivo structure (6.105 when using dried guayule); caution to sample preparation in literature dealing with guayule PI structure. This calls for considering the complex structure of guayule biomass (PI in cells; resin in ducts; chemical instability) when extracting PI. These methods allowed producing high PI Mw glove and tire prototypes and domesticating this new crop in Europe within the EU-Pearls project.MONTPELLIER-BU Sciences (341722106) / SudocSudocFranceF
Novel Engineered Materials: Epoxy Resin Nanocomposite Reinforced with Modified Epoxidized Natural Rubber and Fibers for Low Speed Wind Turbine Blades
No full textThe objective of this study was to investigate nanocomposite materials with good outdoor resistance for wind turbine blade application. The nanocomposites based on epoxy resin with 5% of epoxidized natural rubber (ENR 50), 3% of nanofiller, and glass fibers, were subjected to experiments. The weathering resistance of nanocomposites was evaluated from the change in mechanical properties caused by accelerated aging, induced by UVB radiation in a weathering chamber. The accelerated aging improved tensile strength by about 35% at 168 h of exposure to UVB, via a curing effect. The nanocomposites were optimized for all the parts of wind turbine blades (Savonius and Darrieus types) that are generally designed for high strength, low weight, weathering resistance, and low rotational speed (2 m/s). A tree wind turbine with nanocomposite blades produced 5 kW power output when tested. Based on the findings in this work, the innovative nanocomposites have potential in manufacturing wind turbines to generate electricity
Advancement of an Environmentally Friendly and Innovative Sustainable Rubber Wrap Film with Superior Sealing Properties
No full textCommon kitchen wraps like plastic and aluminum foil create significant environmental burdens. Plastic wrap, typically made from non-renewable fossil fuels, often ends up in landfills for centuries, breaking down into harmful microplastics. Aluminum foil, while effective, requires a large amount of energy to produce, and recycling it at home can be impractical due to food residue. A promising new alternative, low-nitrosamine rubber wrap film, aims to reduce waste by offering a reusable option compared to traditional single-use plastic wrap. The film is environmentally friendly, durable, and effective in sealing containers and keeping food fresh or crispy. The raw materials used to make the product were studied, namely fresh and concentrated natural rubber latex. No nitrosamines were found in either the fresh or concentrated latex, which is important as nitrosamines are known to be carcinogenic. The absence of nitrosamines in the raw materials suggests that the universal rubber wrap film is safe for use. In this study, the rubber formulation and properties of rubber used to make rubber wrap film were studied. The content of additives affecting the rubber properties was varied to find the optimum rubber formulation for making rubber wrap films. The rubber formulation with the least amount of chemicals that met the following criteria was selected: tensile strength of at least 15 MPa, elongation at break of at least 600%, and nitrosamine content below 6 ppm. It was found experimentally that the optimum rubber formulation for making a translucent rubber film had 0.7 phr zinc oxide and 1.0 phr sulfur. Performance tests revealed the rubber wrap film’s superior sealing capabilities. Its elasticity allows for a tighter fit on containers, effectively conforming to various shapes and creating an optimal seal compared to plastic wrap and aluminum foil. The results of this study provide valuable information for developing a universal rubber wrap film that is safe with low nitrosamines
Eco-nanocomposites with epoxidized natural rubber for improved mechanical properties essential to unmanned aerial vehicles propeller applications
No full textParaxylion bifer
No full textParaxylion bifer (Lesne, 1932) Xylion bifer Lesne, 1932: 659. Octodesmus kamoli Chûjô, 1964: 209. syn. nov. Paraxylion bifer – Lesne 1940: 150. The senior author has examined syntypes of P. bifer (MNHN), and we have compared photographs of these with specimens collected in Thailand and Vietnam, and with the holotype, the only known specimen, of O. kamoli (KUM) collected in Thailand. The holotype of O. kamoli has lost the antennal club and the last two segments of the funicle on both sides, but there is no doubt that it is a specimen of P. bifer, which is a common species in Southeast Asia. Accordingly, we here synonymise O. kamoli with P. bifer.Published as part of Liu, Lan-Yu, Beaver, Roger A. & Sanguansub, Sunisa, 2016, A new Oriental genus of bostrichid beetle (Coleoptera: Bostrichidae: Xyloperthini), a new synonym and a lectotype designation for Octodesmus episternalis (Lesne, 1901), pp. 1-12 in European Journal of Taxonomy 189 (189) on page 10, DOI: 10.5852/ejt.2016.189, http://zenodo.org/record/383772
Octodesmus episternalis Lesne 1901
No full textOctodesmus episternalis Lesne, 1901 Octodesmus episternalis Lesne, 1901: 618. When he described the genus Octodesmus, Lesne (1901) did not designate a type species. Fisher (1950) designated Octodesmus episternalis Lesne as the type species. The name is based on a series of syntypes in several museums (Lesne 1901). The senior author has examined syntypes of the species in MNHN. Amongst them is a specimen labelled as lectotype by J.M.Vrydagh, but the designation was never published. In order to fix the identity of the species, we here designate this specimen as lectotype. It bears the labels: “Carin/Asciuli Cheba/ 1200-1300m /L. Fea I-88//³// Octodesmus / episternalis Lesne / type P. Lesne vid.// LECTOTYPE /J.M. Vrydagh”. Both Lesne (1901) and Fisher (1950) note that this is the only known species of Bostrichidae in which the inner margin of the metepisternum is convex towards the ventral midline.Published as part of Liu, Lan-Yu, Beaver, Roger A. & Sanguansub, Sunisa, 2016, A new Oriental genus of bostrichid beetle (Coleoptera: Bostrichidae: Xyloperthini), a new synonym and a lectotype designation for Octodesmus episternalis (Lesne, 1901), pp. 1-12 in European Journal of Taxonomy 189 (189) on page 10, DOI: 10.5852/ejt.2016.189, http://zenodo.org/record/383772
Purification and characterization of amine oxidase from Vigna mungo L. seedlings
Get PDFAmine oxidases (AO) are a group of enzymes that catalyze oxidative deamination of various amines and thus are of potential use in analytical applications. Amine oxidase from five-day-old Vigna mungo L. seedlings (VAO) was purified using ammonium sulfate fractionation and Q-Sepharose chromatography to 544 purification folds with 65% yield. VAO apparently is a homodimer with denatured molecular weight of 73 kDa. This enzyme is relatively stable in a pH range of 6.0 to 8.0 and at temperature below 40°C with a complete activity loss upon storage at pH 4.0 or temperature over 60°C (1 h). Kinetics studies of VAO with putrescine, cadaverine, histamine, and tyramine showed kcat/Km values of 2.54×107, 6.73×106, 2.65×105, and 3.31×103 M–1 s–1, respectively, with undetectable catalytic activity toward tryptamine. VAO was partially inhibited by ethylenediaminetetraacetic acid (EDTA) and completely inhibited by phenylhydrazine, suggesting it is likely a member of copper-containing AO family.Key words: Amine oxidase, cadaverine, histamine, putrescine, tyramine, tryptamine, Vigna mungo L
