The Experts below are selected from a list of 75858 Experts worldwide ranked by ideXlab platform
Frederic Bonfils - One of the best experts on this subject based on the ideXlab platform.
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investigating natural rubber composition with fourier transform infrared ft ir spectroscopy a rapid and non Destructive Method to determine both protein and lipid contents simultaneously
Polymer Testing, 2015Co-Authors: Sebastien Rolere, Siriluck Liengprayoon, Laurent Vaysse, Jerome Saintebeuve, Frederic BonfilsAbstract:A large panel of Natural Rubber (NR) samples was characterized using Fourier Transform Infrared (FT-IR) spectroscopy in Attenuated Total Reflection (ATR) configuration. Specific vibrational bands were attributed to some non-isoprene compounds naturally present in NR composition. A rapid and non-Destructive Method was developed to investigate some specific functional groups contained in lipids (ester and carboxyl groups) and proteins (amides). Ester and carboxyl groups were quantified using calibration curves developed from synthetic cis-1,4-polyisoprene mixtures with either methyl stearate or stearic acid. Amide groups of proteins and peptides were found to be directly quantifiable from NR FTIR spectra. The clonal origin and processing were found to influence the non-isoprene composition of NR. Significant correlations were found between FT-IR results and conventional chemical analyses: nitrogen content for proteins and total lipid extract. (Resume d'auteur)
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investigating natural rubber composition with fourier transform infrared ft ir spectroscopy a rapid and non Destructive Method to determine both protein and lipid contents simultaneously
Polymer Testing, 2015Co-Authors: Sebastien Rolere, Siriluck Liengprayoon, Laurent Vaysse, Jerome Saintebeuve, Frederic BonfilsAbstract:Abstract A large panel of Natural Rubber (NR) samples was characterized using Fourier Transform Infrared (FT-IR) spectroscopy in Attenuated Total Reflection (ATR) configuration. Specific vibrational bands were attributed to some non-isoprene compounds naturally present in NR composition. A rapid and non-Destructive Method was developed to investigate some specific functional groups contained in lipids (ester and carboxyl groups) and proteins (amides). Ester and carboxyl groups were quantified using calibration curves developed from synthetic cis -1,4-polyisoprene mixtures with either methyl stearate or stearic acid. Amide groups of proteins and peptides were found to be directly quantifiable from NR FT-IR spectra. The clonal origin and processing were found to influence the non-isoprene composition of NR. Significant correlations were found between FT-IR results and conventional chemical analyses: nitrogen content for proteins and total lipid extract.
Pierre Roumet - One of the best experts on this subject based on the ideXlab platform.
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potential of field hyperspectral imaging as a non Destructive Method to assess leaf nitrogen content in wheat
Field Crops Research, 2011Co-Authors: Nathalie Vigneau, Martin Ecarnot, Gilles Rabatel, Pierre RoumetAbstract:L'azote est le facteur le plus limitant de la croissance des plantes, aussi sa mesure durant le cycle est un element cle du controle des cultures. De nombreuses techniques de mesure non Destructives basees sur les proprietes optiques de feuilles ont ete proposees pour remplacer la Methode classique couteuse et Destructive de l'indice de nutrition azotee (NNI). Notre objectif est ici d'etudier la possibilite d'acceder a la teneur en azote des feuilles a partir du spectre de reflectance 400-1000nm de plantes entieres, mesure par une camera hyperspectrale, et en prenant en compte les difficultes inherentes a un eclairage naturel variable et a l'eventualite de reflexions speculaires. Dans un premier temps, nous avons etalonne un modele chimiometrique entre la teneur en azote et le spectre de reflectance de feuilles disposees a plat (R² = 0.903, SEP = 0.327 %DM), qui valide le capteur et notre procede de correction en reflectance. Nous avons ensuite etalonne un modele entre la teneur en azote et le spectre de feuilles en place pour des cultures sous serre (R² = 0.889, SEP = 0.481% DM) ou au champ (R² = 0.881, SEP = 0.366 %DM). La reunion des deux jeux de donnees nous permet d'obtenir egalement un modele pertinent pour les deux types de conditions de cultures a la fois (R² = 0.875, SEP = 0.496 %DM), suggerant que cette technique est prometteuse pour la mesure non Destructive de teneur en azote. Cet outil pourra etre utilise pour le suivi dynamique du statut azote ou pour generer des cartographies spatiales de la teneur en azote dans la plante. / Nitrogen is the most important crop limiting factor, thus plant nitrogen status during plant cycle is a key parameter for crop monitoring. Many new techniques, based on leaf optical properties have been proposed for a non-Destructive diagnosis to replace Nitrogen Nutrition Index which is a costly and Destructive Method. We intend here to study leaf nitrogen concentration accessibility from reflectance (4001000 nm) spectra of whole plants from a field hyperspectral imaging set-up including difficulties related to variable solar lighting and potential specular reflexion. Firstly, we calibrated a chemometrical model between leaf nitrogen concentration and reflectance spectra of flat leaves (R2 = 0.903, SEP = 0.327%DM), which validated the sensor and our reflectance correction process. As a second step, we calibrated a chemometrical model between nitrogen concentration and reflectance spectra of individual leaves from isolated plants grown in pots in greenhouse (R2 = 0.889, SEP = 0.481%DM) or underfield conditions (R2 = 0.881, SEP = 0.366%DM). Pooling the two datasets provided us a relevant model to predict leaf nitrogen content for the two culture conditions (R2 = 0.875, SEP = 0.496% DM) suggesting that this technique is promising to assess nitrogen plant parameters with a non Destructive Method. This tool could be used to follow-up plant nitrogen dynamics criteria or to generate nitrogen spatial cartographies.
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potential of field hyperspectral imaging as a non Destructive Method to assess leaf nitrogen content in wheat
Field Crops Research, 2011Co-Authors: Nathalie Vigneau, Martin Ecarnot, Gilles Rabatel, Pierre RoumetAbstract:L'azote est le facteur le plus limitant de la croissance des plantes, aussi sa mesure durant le cycle est un element cle du controle des cultures. De nombreuses techniques de mesure non Destructives basees sur les proprietes optiques de feuilles ont ete proposees pour remplacer la Methode classique couteuse et Destructive de l'indice de nutrition azotee (NNI). Notre objectif est ici d'etudier la possibilite d'acceder a la teneur en azote des feuilles a partir du spectre de reflectance 400-1000nm de plantes entieres, mesure par une camera hyperspectrale, et en prenant en compte les difficultes inherentes a un eclairage naturel variable et a l'eventualite de reflexions speculaires. Dans un premier temps, nous avons etalonne un modele chimiometrique entre la teneur en azote et le spectre de reflectance de feuilles disposees a plat (R² = 0.903, SEP = 0.327 %DM), qui valide le capteur et notre procede de correction en reflectance. Nous avons ensuite etalonne un modele entre la teneur en azote et le spectre de feuilles en place pour des cultures sous serre (R² = 0.889, SEP = 0.481% DM) ou au champ (R² = 0.881, SEP = 0.366 %DM). La reunion des deux jeux de donnees nous permet d'obtenir egalement un modele pertinent pour les deux types de conditions de cultures a la fois (R² = 0.875, SEP = 0.496 %DM), suggerant que cette technique est prometteuse pour la mesure non Destructive de teneur en azote. Cet outil pourra etre utilise pour le suivi dynamique du statut azote ou pour generer des cartographies spatiales de la teneur en azote dans la plante. / Nitrogen is the most important crop limiting factor, thus plant nitrogen status during plant cycle is a key parameter for crop monitoring. Many new techniques, based on leaf optical properties have been proposed for a non-Destructive diagnosis to replace Nitrogen Nutrition Index which is a costly and Destructive Method. We intend here to study leaf nitrogen concentration accessibility from reflectance (4001000 nm) spectra of whole plants from a field hyperspectral imaging set-up including difficulties related to variable solar lighting and potential specular reflexion. Firstly, we calibrated a chemometrical model between leaf nitrogen concentration and reflectance spectra of flat leaves (R2 = 0.903, SEP = 0.327%DM), which validated the sensor and our reflectance correction process. As a second step, we calibrated a chemometrical model between nitrogen concentration and reflectance spectra of individual leaves from isolated plants grown in pots in greenhouse (R2 = 0.889, SEP = 0.481%DM) or underfield conditions (R2 = 0.881, SEP = 0.366%DM). Pooling the two datasets provided us a relevant model to predict leaf nitrogen content for the two culture conditions (R2 = 0.875, SEP = 0.496% DM) suggesting that this technique is promising to assess nitrogen plant parameters with a non Destructive Method. This tool could be used to follow-up plant nitrogen dynamics criteria or to generate nitrogen spatial cartographies.
Sebastien Rolere - One of the best experts on this subject based on the ideXlab platform.
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investigating natural rubber composition with fourier transform infrared ft ir spectroscopy a rapid and non Destructive Method to determine both protein and lipid contents simultaneously
Polymer Testing, 2015Co-Authors: Sebastien Rolere, Siriluck Liengprayoon, Laurent Vaysse, Jerome Saintebeuve, Frederic BonfilsAbstract:A large panel of Natural Rubber (NR) samples was characterized using Fourier Transform Infrared (FT-IR) spectroscopy in Attenuated Total Reflection (ATR) configuration. Specific vibrational bands were attributed to some non-isoprene compounds naturally present in NR composition. A rapid and non-Destructive Method was developed to investigate some specific functional groups contained in lipids (ester and carboxyl groups) and proteins (amides). Ester and carboxyl groups were quantified using calibration curves developed from synthetic cis-1,4-polyisoprene mixtures with either methyl stearate or stearic acid. Amide groups of proteins and peptides were found to be directly quantifiable from NR FTIR spectra. The clonal origin and processing were found to influence the non-isoprene composition of NR. Significant correlations were found between FT-IR results and conventional chemical analyses: nitrogen content for proteins and total lipid extract. (Resume d'auteur)
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investigating natural rubber composition with fourier transform infrared ft ir spectroscopy a rapid and non Destructive Method to determine both protein and lipid contents simultaneously
Polymer Testing, 2015Co-Authors: Sebastien Rolere, Siriluck Liengprayoon, Laurent Vaysse, Jerome Saintebeuve, Frederic BonfilsAbstract:Abstract A large panel of Natural Rubber (NR) samples was characterized using Fourier Transform Infrared (FT-IR) spectroscopy in Attenuated Total Reflection (ATR) configuration. Specific vibrational bands were attributed to some non-isoprene compounds naturally present in NR composition. A rapid and non-Destructive Method was developed to investigate some specific functional groups contained in lipids (ester and carboxyl groups) and proteins (amides). Ester and carboxyl groups were quantified using calibration curves developed from synthetic cis -1,4-polyisoprene mixtures with either methyl stearate or stearic acid. Amide groups of proteins and peptides were found to be directly quantifiable from NR FT-IR spectra. The clonal origin and processing were found to influence the non-isoprene composition of NR. Significant correlations were found between FT-IR results and conventional chemical analyses: nitrogen content for proteins and total lipid extract.
Sahra Talamo - One of the best experts on this subject based on the ideXlab platform.
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saving old bones a non Destructive Method for bone collagen prescreening
Scientific Reports, 2019Co-Authors: Matt Sponheimer, Christina M Ryder, Helen Fewlass, Erin K Smith, William J Pestle, Sahra TalamoAbstract:Bone collagen is an important material for radiocarbon, paleodietary, and paleoproteomic analyses, but it degrades over time, making such analyses more difficult with older material. Collagen preservation between and within archaeological sites is also variable, so that much time, effort, and money can go into the preparation and initial analysis of samples that will not yield meaningful results. To avoid this, various Methods are employed to prescreen bone for collagen preservation (e.g., %N, microporosity, and FTIR spectroscopic analyses), but these are often Destructive and/or require exportation for analysis. Here, we explore near-infrared spectroscopy as a tool for gauging the collagen content of ground and whole bone from about 500 to 45,000 years ago. We show that a portable spectrometer's ability to quantify collagen content and classify specimens by preservation status is comparable to that of other popular prescreening Methods. Moreover, near-infrared spectroscopy is non-Destructive and spectra can be acquired in a few seconds.
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saving old bones a non Destructive Method for bone collagen prescreening
bioRxiv, 2019Co-Authors: Matt Sponheimer, Christina M Ryder, Helen Fewlass, Erin K Smith, William J Pestle, Sahra TalamoAbstract:Abstract Bone collagen is an important material for radiocarbon, paleodietary, and paleoproteomic analyses, but it degrades over time. Various Methods have been employed to prescreen bone for collagen preservation, but these are often Destructive and/or require exportation for analysis. Here we show that near-infrared spectroscopy can be used to determine bone collagen content quickly and non-Destructively on site.r
Kislon Voitchovsky - One of the best experts on this subject based on the ideXlab platform.
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a non Destructive Method to calibrate the torsional spring constant of atomic force microscope cantilevers in viscous environments
Journal of Applied Physics, 2018Co-Authors: Clodomiro Cafolla, Amir Farokh Payam, Kislon VoitchovskyAbstract:Calibration of the torsional spring constant of atomic force microscopy cantilevers is fundamental to a range of applications, from nanoscale friction and lubrication measurements to the characterization of micro-electromechanical systems and the response of biomolecules to external stimuli. Existing calibration Methods are either time consuming and Destructive (ex situ static approaches), or rely on models using the frequency and quality factor (Q-factor) of the cantilever torsional resonance as input parameters (in situ dynamical approaches). While in situ approaches are usually preferred for their easy implementation and preservation of the cantilever, their dependence on the torsional resonance Q-factor renders calibration in highly viscous environments challenging. This is problematic, for example, in many nanoscale tribological applications. Here, we propose a calibration Method that does not depend on the cantilever torsional Q-factor and show how the cantilever deflection can be converted into a lateral force. The Method is tested with six cantilevers of different shapes and material composition and in six fluid media. The derived spring constants are compared with predictions from existing Methods, demonstrating a higher precision, in particular, for highly viscous liquids.Calibration of the torsional spring constant of atomic force microscopy cantilevers is fundamental to a range of applications, from nanoscale friction and lubrication measurements to the characterization of micro-electromechanical systems and the response of biomolecules to external stimuli. Existing calibration Methods are either time consuming and Destructive (ex situ static approaches), or rely on models using the frequency and quality factor (Q-factor) of the cantilever torsional resonance as input parameters (in situ dynamical approaches). While in situ approaches are usually preferred for their easy implementation and preservation of the cantilever, their dependence on the torsional resonance Q-factor renders calibration in highly viscous environments challenging. This is problematic, for example, in many nanoscale tribological applications. Here, we propose a calibration Method that does not depend on the cantilever torsional Q-factor and show how the cantilever deflection can be converted into a l...