Дисертації з теми "Carbide plate"
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Barnes, Andrew Charles. "Characterization of High-Aspect Ratio, Thin Film Silicon Carbide Diaphragms Using Multimode, Resonance Frequency Analysis." Case Western Reserve University School of Graduate Studies / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=case1414844482.
Повний текст джерелаЧміль, Роман Євгенович. "Свердло з напайною твердосплавною пластиною". Master's thesis, Київ, 2018. https://ela.kpi.ua/handle/123456789/26719.
Повний текст джерелаThe forms of the cutting parts of the spiral drills, which are used in modern mechanical engineering, are considered. The changes of the front, rear angles and the thickness of the cutting layer, for drills with a radius shape of the cutting part and the drill with an angle with the apex along the cutting edge. It is established that the drill with a radius shape of the cutting part with a radius at an apex of 8 mm has the most favorable geometric parameters. A technological tool for manufacturing a drill with optimization of its production has been developed. A startup project of the idea of this drill was developed
Martin, Samuel R. "Experimental Characterization of the Effect of Microstructure on the Dynamic Behavior of SiC." Thesis, Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/5024.
Повний текст джерелаLeray, Cedric. "Etude du comportement thermique et thermomécanique des récepteurs solaires sous haut flux radiatif." Thesis, Perpignan, 2017. http://www.theses.fr/2017PERP0003/document.
Повний текст джерелаFor the future, using thermodynamical solar power plant seems to be a good solution to ensure electrical production. Solar tower plants are able to produce electricity in significant amount, are environmentally friendly and economically competitive. One way to increase the yield of these plants is using high efficiency thermodynamical cycles, like combined cycle. That requires to providing a working fluid at high temperature and high pressure (10bar and 1000°C at least). This PHD thesis presents the works performed to develop and enhance a concept of modular plate solar ceramic absorber that can ensure the required air production. We chose the silicon carbide as material due to its resistance to high temperatures and oxidation problems. The drawback is ceramic modules are weak to traction stresses. The study focuses on the knowledge and the control of this phenomenon. This work combines the developments of numerical tools and experimental studies performed at Thémis power plant (Targassonne, 66, FRANCE). The numerical method permits simulations to predict the thermal behavior and the mechanical behavior of a solar module absorber. It allows the reduction of the mechanical stresses undergone by solar receiver and the prediction of its performances. This methodology was tested using experimental results
Таран, Євгеній Сергійович. "Оправка розточна збірна". Bachelor's thesis, КПІ ім. Ігоря Сікорського, 2019. https://ela.kpi.ua/handle/123456789/31456.
Повний текст джерелаThe purpose of the diploma project is the design of the mandrel of the blade assembly, which is used for the treatment of internal and external cylindrical surfaces, drilling a hole, rolling the grooves and triming the ends. This tool is equipped with replaceable carbide plates, which are securely mounted in the tool casing. The structure of the tools for processing various types of surfaces was also analyzed, a working drawing and a 3D model of the tool were created, a production technology was developed and cutting patterns were calculated, a technological device for milling the landing surfaces under a solid alloy plate was selected and calculated, the control program for the CNC machine and visualization of the processing process are presented.
Brun, François. "Modélisation du fonctionnement de la plante Arabidopsis thaliana dans différents contextes de disponibilité en N du sol : impact sur l'architecture racinaire." Paris 11, 2006. http://www.theses.fr/2006PA112256.
Повний текст джерелаA nitrogen limitation causes important effects on the development and the growth of the plant that presents an adaptative response under such conditions. The plasticity of the root system is an essential element of this response. The objective of this study was to analyze the response of the root system to a nitrogen limitation by trying to take into account the whole plant functioning. We chose a modelling approach to simulate the whole plant functioning in Arabidopsis thaliana with a detailed description of the morphogenetic processes of the root system under contrasted nitrogen conditions. Experiments were carried out under cross conditions carbon and nitrogen nutritions to specify these effects on the root system architecture and to collect data for our modelling approach of the whole plant. Most of our study is on one genotype, the ecotype Wassilewskija (Ws-0), and proposes an analysis framework for future studies on genetic variability
Larue, Camille. "Impact de nanoparticules de TiO2 et de nanotubes de carbone sur les végétaux." Phd thesis, AgroParisTech, 2011. http://pastel.archives-ouvertes.fr/pastel-00765312.
Повний текст джерелаPellan, Maxime. "Développement des joints de grain et des joints de phase dans les carbures cémentés WC-CO." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAI121/document.
Повний текст джерелаWC-Co cemented carbide is a two phase system constituted of a cobalt based binder matrix embedding hard tungsten carbide grains. This material is especially used in fields such as metal cutting or mining, where high mechanical properties are required. Therefore, the microstructure is a key parameter to control to optimize the mechanical properties of the alloy.This work aims at understanding the mechanisms of grain boundary and phase boundary development during sintering, and how they may influence the final microstructure. The effect of the binder content, carbon content and sintering time was especially investigated.Electron BackScattered Diffraction characterization was chosen to conduct this study. First because the precise separation of grains in the resulting images makes possible automation of the measurements, and thus allows a statistical analysis of several microstructural parameters (as grain size, contiguity) on numerous samples. Secondly because orientation data collected by this way make possible the analysis of grain boundary and phase boundary texture. To this end, an automated method was developed for analysis of grain boundaries and estimation of remarkable boundary planes fraction from 2D EBSD measurements.The study of contiguity shows that it does not depend on sintering time or carbon content in the binder, but essentially of the carbide grain volume fraction. This result implies that impingement is the first order parameter in the evolution of contiguity. Grains appear to grow faster and in a larger extent in samples with a carbon rich binder, as well as in high binder content samples. Abnormal grain growth seems to be favored by high binder content in carbon rich samples. All grain boundaries were characterized by a couple of rotation axis and misorientation angle. Three particular rotation axes were identified: [101 ̅0], [21 ̅1 ̅0] and [0001]. They represent around 30% of the total grain boundary surface area. In addition, specific rotations were found to be particularly abundant in the microstructure: [101 ̅0]/90°, [21 ̅1 ̅0] / (48°- 60°- 90°) and [0001]/90°.A study of their geometry suggests that their stability would be due to a particularly coherent boundary plane. A statistical analysis shows that most grain boundaries and phase boundaries have a habit plane parallel to a basal or prismatic plane (about 70% of the total grain boundary surface area and 50% of the total phase boundary area. Finally, a scenario is proposed for the microstructure development model during sintering of cemented carbides on the basis of the results
Kohler, Caroline. "Fonctionnement des communautés végétales et stocks de carbone en prairies bas-normandes." Caen, 2015. http://www.theses.fr/2015CAEN2073.
Повний текст джерелаGrasslands are recognized for their high potential to mitigate the increase in atmospheric CO2 concentrations through carbon (C) storage in soils. At the interface between the soil and the atmosphere, plant communities constitute a key component driving C inputs and C outputs in the ecosystem. This work aims to determine the impact of the functional composition of plant communities on C stocks and C distribution in grasslands, and to assess the underlying mechanisms. We studied in situ the C stocks in the plant-soil system of seven grasslands in an experimental farm in Normandy, and characterized the functional composition of the plant communities. This study shows that the functioning of plant communities affects soil C stocks. The LDMC (leaf dry matter content) community-weighted mean trait, proved to be the best indicator of soil C stocks. Overall, the results highlight the importance of the grassland age: the oldest and least productive grasslands have a higher soil C stock than the most recent and productive ones. The oldest grasslands are also characterized by a high root C amount, which is positively correlated with the soil organic C stock. The positive correlation between the stubble carbohydrate contents and the soluble soil C contents in spring suggests an impact of root carbohydrate exudation on the quality of soil organic matter and soil microbes C. Overall, our results highlight the need for a compromise between forage production and soil C storage
Razakamanarivo, Ramarson Herintsitohaina. "Potentialités de stockage du carbone dans le système plante-sol des plantations d'eucalyptus des hautes terres malgaches." Montpellier SupAgro, 2009. http://www.theses.fr/2009NSAM0028.
Повний текст джерелаLundgren, Rose Tatiana. "Analyse cellulaire et moléculaire de l'autophagie : effets de carences en carbone chez la plante modèle Arabidopsis thaliana et la plante d'intérêt économique Vigna unguiculata." Dijon, 2005. http://www.theses.fr/2005DIJOS017.
Повний текст джерелаBiochemical, cytological and molecular methods have been used to study autophagy, a catabolic process by which cells degrade parts of their own cytoplasm. Autophagy was induced in Arabidopsis thaliana and Vigna unguiculata suspension-cultured cells by carbon starvation. Quantification of autophagy-related structures (autophagosomes and pre-autophagosomat structures) shows that cells respond to the stress signal by a rapid and massive burst of autophagic activity. It is shown that the autophagy-related genes AtATG3, AtATG4a, AtATG4b, AtATG7 and AtATG8a-i, involved in the ATG8 ubiquitination-like conjugation pathway, are up-regulated in a coordinated manner at the onset of starvation. They are expressed in successive waves that parallel the biochemical and cytological remodeling that takes place. A preliminary pharmacological approach suggests that the TOR (target of rapamycin) pathway can play an important role in autophagy signalling
Devivier, Cédric. "Damage identification in layered composite plates using kinematic full-field measurements." Troyes, 2012. http://www.theses.fr/2012TROY0017.
Повний текст джерелаThis work focuses on the development of an experimental technique which can help to define the key parameters for post-impact behaviour of laminated composite panels. To address this issue, finite element models were built to represent delaminations based on the observations of CT-scans of impacted samples. The results of these models have been correlated to experimental data obtained using a slope fullfield measurement technique: deflectometry. This work also develops a new damage indicator based on the application of the virtual fields method to compute a local equilibrium gap. The procedure is first presened and then applied to beam and plate samples. The experimental results illustrate the remarkable sensitivity of this measurement method as it captures the effect of very small amount of damage and shows that the simple numerical models need to be refined to present a better correlation to experimental results. The damage indicator successfully detects contours of damaged areas when sufficient spatial information is available. It is believed that pursuing the present work could lead to an invaluable tool to help design engineers
Manac'h, Lilia. "Conception et réalisation d'antennes en matériaux composites : intégration dans des plates-formes." Thesis, Rennes 1, 2013. http://www.theses.fr/2013REN1S079.
Повний текст джерелаThe technical and operational requirements of naval, terrestrial and aerial vehicles lead to the design and installation of a great number of antennas for communications. At the same time, composite materials have been used for many decades in structural panels of vehicles for their intrinsic qualities (lightness, high mechanical performance, insensitivity to corrosion ...). The purpose of this manuscript is the study and engineering of composite materials for antenna applications at microwaves. After an exhaustive survey of the dielectric characteristics of the various elements of composite materials, dielectric characterization of composite materials manufactured in the Laboratory was carried out using two different methods in two different frequency bands. Meanwhile, an analysis of their conductive characteristics allows carbon-fiber tissues to be used in the design of radiating elements. First, two "full-composite" square shaped antennas based on carbon-fiber tissues, glass-fiber tissues and polyester or epoxy resin have been developed, fabricated and measured. Their performance, similar to that of reference metal antennas demonstrates their relevance for microwave applications. Then, three different topologies of ultra wideband "full-composite" antennas have been specifically developed for the SAMCOM (/Antenna Systems in COMposite Materials)/ FUI project. The first, a Rugby-Ball shaped antenna, has one octave and a half of bandwidth with a positive gain and λ/4 x λ/4 x λ/10 dimensions (length x width x height). The second, a 3D dipole antenna with λ/3 x λ/3 x λ/10 dimensions, has two octaves and a half of bandwidth also with a positive gain. At last, the third antenna with a planar structure has been specifically developed for the reception of digital terrestrial television (DTT) and will be, at the end, integrated into a structural panel of a terrestrial vehicle
Goislard, de Monsabert Thomas. "Couches de nanotubes et filaments de carbone pour l'émission froide d'électrons : intégration aux écrans plats à émission de champ." Université Joseph Fourier (Grenoble), 2006. http://www.theses.fr/2006GRE10043.
Повний текст джерелаThis work concerns the in situ elaboration, by catalytic CVD, of carbon nanotubes and filaments films for their integration as electron emissive films into field emission displays. The key parameters, advantages and restrictions of several techniques for catalyst nano particles preparation and integration were first analysed : dewetting of a continuous layer, post-dewetting wet etching, nano cluster deposition and e-beam lithography. Three growth techniques were then studied in the same reactor : simple thermal CVD, CVD with an electrical field and plasma assisted CVD from a solid carbon source. Finally, the emissive properties of the elaborated carbonaceous films were measured, in diode mode for the full sheet type samples and in triode mode for the films integrated into display cathodic structures. Theses results analysis permitted to clarify the links between technological elaboration parameters, morphology and emissive performances of carbon nanotubes and filaments films
LUGEN, DANIEL. "Extraction au co2 supercritique appliquee aux plantes medicinales." Strasbourg 1, 1992. http://www.theses.fr/1992STR15063.
Повний текст джерелаThiollière, Nicolas. "Mesure des sections efficaces de diffusion élastique des neutrons sur le carbone et le fluor dans le domaine épithermique sur la plate-forme PEREN." Grenoble 1, 2005. http://www.theses.fr/2005GRE10173.
Повний текст джерелаMolten Salt Reactor (MSR) based on Th/U cycle is one of the new generation concepts for nuclear energy production. A typical MSR is a graphite-moderated core with liquid fuel (7LiF+ThF4+UF4). Many numerical studies based on Monte-Carlo codes are currently carried out but the validity of these numerical result relies on the precise knowledge of neutron cross sections used such as elastic scattering on carbon (σC), fluorine (σF) and lithium 7 (σLi). The goal of this work is to obtain σC and σF between 1 eV and 100 keV. Such measurements have been performed at the Laboratoire de Physique Subatomique et de Cosmologie (LPSC) de Grenoble on the experimental platform PEREN using slowing-down time spectrometers (C and CF2) associated to a pulsed neutron generator (GENEPI). Capture rates are obtained for reference materials (Au, Ag, Mo and In) using YAP scintillator coupled to a photo-multiplier. Very precise simulations (MCNP code) of the experimental setup have been performed and comparison with experiments has led to the determination of σC and σF with accuracies of 1% and 2% respectively. These results show a small discrepancy to evaluated nuclear data file (ENDF). Measures of total cross-sections σC and σF at higher energy (200-600, keV) were also carried out at Centre des Etudes Nucléaires de Bordeaux using a transmission method. Mono-energetic neutrons were produced by protons accelerated by a Van de Graaff accelerator on a LiF target and transmitted neutrons are counted in a proportional hydrogen gaseous detector. Discrepancies of 5\% and 9\% for σC and σF respectively with ENDF have been shown
Baylet, Jacques. "Etude de couches minces de carbone et de leurs propriétés d'émission électronique : application aux écrans plats à effet de champ." Université Joseph Fourier (Grenoble), 2000. http://www.theses.fr/2000GRE10001.
Повний текст джерелаLecuyer, Oskar. "Quelle place pour les aides aux technologies de réduction d'émissions en présence d'un prix du carbone? : le cas du secteur électrique." Phd thesis, Ecole des Hautes Etudes en Sciences Sociales (EHESS), 2013. http://tel.archives-ouvertes.fr/tel-00914477.
Повний текст джерелаPageau, Karine. "Nutrition azotee et metabolisme de l'azote chez une plante hemiparasite de racine striga hermonthica (del. ) benth. : relation avec le metabolisme carbone." Nantes, 2001. http://www.theses.fr/2001NANT2021.
Повний текст джерелаPicard, Quentin. "Biomatériaux hybrides : tissu de fibres de carbone / phosphates de calcium : synthèse, caractérisation et biocompatibilité." Thesis, Orléans, 2015. http://www.theses.fr/2015ORLE2073/document.
Повний текст джерелаThis work is focused on the synthesis of a novel hybrid biomaterial made of carbon fibers cloth (CFC)/ calcium phosphates (CaP) using the sono-electrochemical technique and the study of the influence of experimental parameters on the chemical composition, microtexture and structure of CaP deposits and on in vitro biocompatibility. Current density is shown to be a crucial parameter. Specifically, at high current densities ((≥ 100 mA/g), the fast water electrolysis rate leads to a needle-like deposit consisting in a major phase of carbonated calcium deficient hydroxyapatite (CaD-HAP) mixed with a calcium carbonate phase. At low current densities (≤ 50 mA/g), the slow water electrolysis rate generates a plate-like carbonated CaD-HAP phase, coming from the in situ hydrolysis of a former octacalcium phosphate phase. Whatever the experimental conditions, particles of the deposits consists in a carbonated CaD-HAP core showing an ordered structure, surrounded by a hydrated and disordered carbonated CaD-HAP surface layer which results of the formation of oversaturated domains during CaP precipitation. Sono-electrodeposition is shown to be a versatile process able to control the nature of CaP phases. Especially, at low current density a biomimetic CaP deposit is obtained, similar to the mineral part of bones produced during natural osteogenesis. In vitro biologic tests using primary human osteoblasts showed that the nano-porosity and hydrophilicity of the carbon fibers do not affect the biocompatibility and that fiber precursor, sizing and lobe shaped fibers seems to favor adhesion and proliferation of human cells
Mulier, Maxime. "Mise en place d'un spectromètre laser infrarouge pour l'étude de la diffusion du CO2 gazeux hors du champagne et de quelques boissons effervescentes." Reims, 2009. http://theses.univ-reims.fr/sciences/2009REIMS034.pdf.
Повний текст джерелаRecent studies on champagne wine's CO2 bubbles attempt to draw the link between bubbles ascending in a champagne glass, CO2 gas diffusion from champagne and champagne flavour molecules freeing at the liquid/air surface. In order to progress in the understanding of the role of champagne bubbles in the CO2 diffusion mecanism, we have set up a direct absorption spectrometer based on near-infrared technology; relatively precise CO2 gas concentrations are measured and the mounting is thought to be adapted to a glass-shape change. Our open to the atmosphere spectrometer is based on a new generation laser diode emitting at 2,7 µm, centered at 3728 cm-1, resulting in an optimum absorption scale with a little pathlength. We have defined a protocol insuring a quite good measurements reproducybility with conditions very close to the champagne tasting conditions: thus, we paied attention to human activity "insulation", beverage temperature stabilisation, and champagne glass cleaning. First application of the sensor to a glass fullfilled with champagne showed the effect of temperature on CO2 diffusion with time. Also, second application of the sensor has been done to a glass fullfilled with some other sparkling beverages, each other having different initial CO2 concentrations; the solubility of CO2 in the beverage seems to influence CO2 diffusion with time. Finally, a mathematical model of the CO2 outgassing from a glass of champagne is required in order to complete the results and some elements are drawn in this work to describe the diffusion by mass convection at the free surface
Bazot, Stéphane. "Contribution à l'étude de l'allocation des photoassimilats récents dans la plante et la rhizosphère chez une graminée pérenne (Lolium perenne L. )." Phd thesis, Institut National Polytechnique de Lorraine - INPL, 2005. http://tel.archives-ouvertes.fr/tel-00137743.
Повний текст джерелаNous avons d'abord déterminé la contribution du carbone récemment assimilé par la plante à la rhizodéposition. Nous avons ainsi réalisé un double marquage long des parties aériennes des plantes (14CO2 et 13CO2) afin d'estimer la répartition dans la plante et les compartiments rhizosphériques du C récent et le C plus anciennement assimilé. Contrairement à ce qui est admis généralement, le C ancien, probablement issu de la remobilisation de composés de réserve, contribue significativement à la rhizodéposition.
Nous avons ensuite évalué sur des dispositifs expérimentaux de terrain l'influence de contraintes subies par les parties aériennes de la plante sur les flux de C récent vers la rhizosphère (augmentation de la concentration en CO2 atmosphérique et défoliation). La disponibilité en azote dans le sol est un facteur déterminant de la réponse des plantes à l'élévation des concentrations en CO2 ou à la défoliation. A l'automne, une diminution de la rhizodéposition de C est observée pour les plantes soumises au doublement de CO2. Les composés organiques libérés par les racines sont minéralisés plus rapidement sous CO2 élevé que sous CO2 ambiant. La défoliation n'induit pas de variations notables de la disponibilité en C dans la rhizosphère, suggérant aucune influence significative de ce facteur sur la rhizodéposition.
Les interactions entre les facteurs de l'environnement et de gestion de la parcelle cultivée déterminent le fonctionnement de la plante et modulent les efflux de C à partir des racines, ce qui rend la rhizodéposition difficile à prédire et à modéliser. Il s'avère que les effets nets du doublement de CO2 ou de la défoliation sur la rhizodéposition sont beaucoup moins marqués au champ qu'en conditions contrôlées. Au delà de la contribution quantitative de la rhizodéposition au bilan de C dans le sol, les interactions entre la nature biochimique des rhizodépôts et l'activité biologique des sols nécessitent d'être approfondies.
Bonin, Aurélie. "Relations entre les variations climatiques, les perturbations du cycle du carbone et les crises de la production carbonatée : application au Crétacé inférieur." Phd thesis, Université de Bourgogne, 2011. http://tel.archives-ouvertes.fr/tel-00705496.
Повний текст джерелаDulermo, Thierry. "Transfert du carbone au cours de l'infection du tournesol par le champignon nécrotophe B. Cinerea : des hexoses de la plante au mannitol fongique." Lyon 1, 2009. http://www.theses.fr/2009LYO10002.
Повний текст джерелаOur work was completed on Botrytis cinerea, a necrotrophic ascomycete fungus. The first stage of our work consisted in drawing up an inventory of the soluble carbon metabolites present in partners of infection: Botrytis cinerea and sunflower cotyledons and to follow their evolution during the infection. During the colonization of the cotyledons of sunflower, hexoses from plant disappear, whereas mannitol of fungal origin is accumulated. In order to highlight the elements implied in the disappearance of hexoses in the plant, we sought genes potentially implied in the transport of hexoses in the genome of B. Cinerea. The bioinformatic analyses made it possible to characterize eighteen sequences like transmembrane proteins implied in the transport of hexoses. Transcriptional profiles of these genes indicate a great flexibility of expression during infection as during in vitro development. Once transported, plant’s hexoses are metabolized by fungi. In order to know to become to it hexoses, we followed their assimilation thanks to the use of marked sugars. This approach was coupled with an analysis of the way of synthesis of the mannitol, metabolite carbonaceous prevalent accumulated by B. Cinerea in answer to the assimilation of sugars. It exists two mannitol biosynthesis pathways in Ascomycetes fungi and the results obtained with B. Cinerea, propose new prospects of operation and make it possible to better determine the importance of each way in the metabolism of the mannitol
Gabrielle, Benoît. "Modélisation des cycles des éléments eau-carbone-azote dans un système sol-plante et application à l'estimation des bilans environnementaux des grandes cultures." Châtenay-Malabry, Ecole centrale de Paris, 1996. http://www.theses.fr/1996ECAP0491.
Повний текст джерелаThe field-assessment of the environmental impacts of crop production has emerged as a critical issue, since modern agriculture should be expected not to pose major threats. We have here assessed the nitrogen (N) pollutions, caused by such a crop (oilseed rape), through both experimental and modeling approaches. Two types of pollution were investigated : the leaching of nitrate below the root zone, and the gaseous emissions of ammonia (NH3) and nitrous oxide (N2O) to the atmosphere. The prediction of N fluxes at the boundaries of the soil-crop system requires the use of a model simulating the dynamics of water, carbon and N within this system. Among the approaches of various complexities undertaken in the literature, we chose two models representing either a simple (CERES) or a more theoretical (DAISY) viewpoint. Five data sets corresponding to a range of climate and soil conditions were used to test various options for both models. None of the models clearly outranked the other. DAISY performed better as regards heat and mass transfer in soil, but CERES proved a superiority for the simulation of crop growth. Actually, the precisions of the models were also dependent on the type of medium investigated : we then suggested that a functional classification of soils could serve as a basis for determining the form of model to use, that would offer the best precision for a given set of available inputs. Overall, the modifications we proposed to the soil components of CERES allowed this simple approach to yield a satisfactory accuracy in the prediction of the water, carbon and nitrogen fluxes in the soil-crop system
ABDELHAFID, RAHINA. "Mineralisation acceleree de l'atrazine dans les sols : conditions de mise en place, caracterisation et influence de la disponibilite en carbone et en azote." Paris, Institut national d'agronomie de Paris Grignon, 1998. http://www.theses.fr/1998INAP0032.
Повний текст джерелаKang, Seungwoo. "La place de la bioénergie dans un monde sobre en carbone : Analyse prospective et développement de la filière biomasse dans le modèle TIAM-FR." Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLEM081/document.
Повний текст джерелаWith growing concerns about the environment, countries are increasing efforts to reduce their fossil fuel dependency, the major source of greenhouse gas emissions, by replacing them with clean energy sources including bioenergy. In this context induced by the Paris’ Agreement and climate change mitigation targets, the bioenergy is being highlighted in the pathway to the decarbonization of our society. The work of this thesis concentrates on the perspectives of bioenergy development aiming to analyze the evolution of bioenergy production in view of policies, global exchange of biomass resources and the sustainable utilization of bioenergy in the long term in a context of decarbonization of societies. In terms of analysis, this thesis focuses also on the better implementation of bioenergy chain in our global energy system optimization model, TIAM-FR. This manuscript is structured in four chapters. The first chapter presents the actual position of bioenergy, bioenergy development strategy as well as the way how they are integrated into our modeling approach. The second chapter is dedicated to present the developments effectuated for the bioenergy chain in the model TIAM-FR. The third chapter shows our work regarding the evaluation of biomass resources potentials. Lastly, the role of bioenergy in the climate change mitigation context has been discussed at a global scale and by a focus on four Asian countries, China, India, Japan and South Korea
Ponsot, Bernard. "Influence de la matrice sur le comportement a long terme de composites carbone-epoxyde." Paris, ENMP, 1987. http://www.theses.fr/1987ENMP0058.
Повний текст джерелаEstelrich, Hector Daniel. "Allocation du carbone chez une Graminée annuelle (Bromus madritensis L. ) et une Graminée pérenne (Bromus erectus Hud. ) cultivées sur deux sols de fertilité différente : importance de l'"effet rhizosphère"." Montpellier 2, 1990. http://www.theses.fr/1990MON20262.
Повний текст джерелаQuereix, Anne. "Analyse et modélisation du fonctionnement stomatique de la vigne Vitis vinifera L. : intégration de l'effet des puits de carbone sur les échanges gazeux de la plante." Bordeaux 2, 2001. http://www.theses.fr/2001BOR20834.
Повний текст джерелаIn order to understand the control of grape quality, it is necessary to quantify the capture of plant resources and their partitioning between the various organs. This requires, in particular, an integrated description of plant gas exchange in response to both environmental and internal factors. Currently, however, the coupling of these two types of factors remains poorly understood. The objective of this study is to develop a model of gas exchange taking into account the short-term effects of climate as well as the influence of source-sink interactions on the stomatal conductance and photosynthesis. We first analysed experimentally the interactions between the carbon supply of sources and the carbon demand of sinks, under a stable environment and also in the vineyard. Then from these data, we developed a dynamic model based on (i) an empirical model of stomatal conductance (Leuning, 1995), modified in the light of published studies, and (ii) a model of carbon partitioning (Minchin et al,1993), to which we added a source-sink feedback mechanism. Simulations show that the model reproduced the global tendencies observed for photosynthesis and stomatal conductance in a stable environment. Less satisfactory agreement was obtained in the vineyard under a fluctuating environment. Nevertheless, from a qualitative point of view, the model accounts for the interactions between organs and simulates the observed behaviour following the modification of the source-sink ratio. By integrating the influence of external factors, this study provides a preliminary model for incorporating the sink feedback effect on source activity, which may be integrated into models describing the longer term functioning of whole plants
Bonal, Damien. "Variabilité interspécifique de l'efficience d'utilisation de l'eau en forêt tropicale humide guyanaise : groupes fonctionnels, interprétation écophysiologique, intégration à l'échelle du couvert." Nancy 1, 2000. http://docnum.univ-lorraine.fr/public/SCD_T_2000_0006_BONAL.pdf.
Повний текст джерелаRouhier, Hervé. "Réponse du châtaignier (Castanea sativa Mill. ) à l'augmentation du CO² atmosphérique : croissance et activité rhizosphérique." Lyon 1, 1994. http://www.theses.fr/1994LYO10140.
Повний текст джерелаDurand, Mickael. "Étude de l'allocation du carbone dans la plante en réponse à la contrainte hydrique : impact sur l'expression des transporteurs de saccharose dans les organes source et puits." Thesis, Poitiers, 2015. http://www.theses.fr/2015POIT2306/document.
Повний текст джерелаThe aim of this thesis was to investigate the sucrose transporters involved in sink organs development, and more precisely their role in roots of plants submitted to water deficit.The expression of AtSUCs and AtSWEETs transporters was mapped during the full development of A. thaliana plants grown hydroponically in rosette, stem, siliques and roots. In parallel, we evaluated C partitioning and sugar metabolism in whole plant during development to finally (1) get an insight on C allocation, sugar metabolism and sucrose transporters genes expression and (2) discuss their possible relationships.Secondly, we designed an innovating soil culture system, called “Rhizobox” which allows clean roots harvest, root system architecture analysis and water deficit experiment. Under water deficit, root growth was reduced, but in depth root exploration was maintained probably to improve water uptake. In addition, although shoot submitted to water deficit were smaller, 14C exported to the roots increased. In the same time, the transcript levels of the sucrose effluxers gene AtSWEET11 and AtSWEET12 and the companion-cell specific sucrose:H+ symporter gene AtSUC2, all three involved in sucrose phloem loading, are up-regulated in leaves of water deficit plants, agreeing with the increase in carbon export to the roots. Interestingly, the transcript levels of AtSUC2, and AtSWEET11-15, were higher in stressed roots, underlying (1) the potential existence of sucrose apoplastic unloading in Arabidopsis roots and (2) a putative role for these sucrose transporters in sucrose unloading in root since they are mainly expressed in root zones where C demand is high
Tubeileh, Ashraf. "Photosynthèse, répartition des assimilats et rhizodéposition chez le maïs (Zea Mays L. ) soumis à la compaction du sol." Vandoeuvre-les-Nancy, INPL, 2000. http://docnum.univ-lorraine.fr/public/INPL_T_2000_TUBEILEH_A.pdf.
Повний текст джерелаThe objective of this work was to investigate the effects of soil compaction on carbon assimilation, photosynthate partitioning, and morphology of corn plants during vegetative growth period up to tassel initiation. We were particularly interested in carbon input into the soil and soil microbial biomass. Corn plants were grown in culture pots containing compacted soil (bulk density of 1. 45 g cm-3 ) or loose soil (bulk density of 1. 30 g cm-3). Experiments were conducted in a growth chamber and lasted for 21 to 42 days. Carbon partitioning in the plant-soil system was evaluated using 14C pulse-labeling techniques. The increase in soil bulk density decreased carbon assimilation rate and total carbon fixation. Furthermore, soil compaction delayed leaf appearance rate decreasing therefore plant height, shoot dry weight, and leaf area. In addition, root biomass and root elongation were also inferior when plants were grown in compacted soil and root length appeared to be the most sensible parameter to high soil mechanical resistance. Simultaneously, a great increase in carbon input into the soil occurred to the detriment of root carbon. Soil microbial biomass increased considerably in compacted soil thanks to this increase in carbon substrates and to physical protection provided for soil microflora as a result of the reduced porosity in compacted soil. Three hypotheses were formulated to explain these results: 1- a decrease in soil or root water potential or a sink limitation induces a down-regulation of photosynthetic activity, 2- the increase in root diameter decreases soil mechanical resistance, and 3- the increase in carbon rhizodeposition alleviates the effects of mechanical constraint. The effects of soil compaction persisted with plant age although the difference between the two treatments decreased in terms of percentage
Brossard, Christophe. "Contribution à l'étude de l'inhibition de la post-combustion : caractérisation aérothermochimique d'une flamme plane basse pression ensemencée en potassium." Rouen, 1995. http://www.theses.fr/1995ROUES054.
Повний текст джерелаЗалога, Вільям Олександрович, Вильям Александрович Залога, Viliam Oleksandrovych Zaloha, Костянтин Олександрович Дядюра, Константин Александрович Дядюра, Kostiantyn Oleksandrovych Diadiura, Олександр Володимирович Івченко та ін. "Нормативне забезпечення неруйнівного експрес-методу оцінювання якості лез різального інструменту". Thesis, Сумський державний університет, 2017. http://essuir.sumdu.edu.ua/handle/123456789/66758.
Повний текст джерелаMarchetti, Fabien. "Modelling and characterisation of anisotropic multilayered plates on a wide frequency range." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI130.
Повний текст джерелаThis PhD thesis concerns the modelling and the dynamic characterisation of anisotropic multilayered structures. In the first chapter, a classification of some analytical models and experimental methods of characterisation is presented in the form of a bibliographical synthesis where the main published results are gathered. The second chapter introduces an extension of an equivalent model of multilayered structures to the case of anisotropic materials. This model describes the first dispersion curves of the structure and considers the shear phenomena that can affect the bending mode in high frequencies. The main advantage of the model lies in its simplicity and rapidity thanks to a number of kinematic variables independent of the number of layers. The characteristics of the multilayer are defined by the 5 flexural rigidities of a thin equivalent plate which is compared to the multilayer. The results of the model are validated by means of an experimental study on carbon fiber composite plates. A particular interest is dedicated to the modelling of structural damping. An energetic loss factor, based on a temporal and spatial definition of the attenuation, is compared to an equivalent one. A new definition of the spatial attenuation is suggested for high damped structures and is compared to literature. In the third chapter, the methodology of the characterisation technique CFAT is adapted for anisotropic plates. This inverse method is based on the displacement field analysis of the structure and has, by means of its local aspect, relevant advantages for industrial applications. This adaptation is, as a first step, introduced for the identification of sources (initial objective of the method) and applied, in a second step, for the characterisation. Several numerical and experimental applications are presented to validate the results of the method. Finally, the fourth chapter deals with the experimental characterisation of a honey comb sandwich on a high frequency range (1 to 300 kHz). The complex dynamic behaviour of this thick structure is described through the promissing results given by the simulations of our model and the estimations of RIC. These results are also compared to the ones of a reference model and other characterisation methods
Hache, Florian. "Vibration of nonlocal carbon nanotubes and graphene nanoplates." Thesis, Lorient, 2018. http://www.theses.fr/2018LORIS487/document.
Повний текст джерелаThis thesis deals with the analytical study of vibration of carbon nanotubes and graphene plates. First, a brief overview of the traditional Bresse-Timoshenko models for thick beams and Uflyand- Mindlin models for thick plates will be conducted. It has been shown in the literature that the conventionally utilized mechanical models models overcorrect the shear effect and that of rotary inertia. To improve the situation, two alternative versions of theories of beams and plates are proposed. The first one is derived through the use of equilibrium equations and leads to a truncated governing differential equation in displacement. It is shown, by considering a power series expansion of the displacement, that this is asymptotically consistent at the second order. The second theory is based on slope inertia and results in the truncated equation with an additional sixth order derivative term. Then, these theories will be extended in order to take into account some scale effects such as interatomic interactions that cannot be neglected for nanomaterials. Thus, different approaches will be considered: phenomenological, asymptotic and continualized. The basic principle of continualized models is to build continuous equations starting from discrete equations and by using Taylor series expansions or Padé approximants. For each of the different models derived in this study, the natural frequencies will be determined, analytically when the closed-form solution is available, numerically when the solution is given through a characteristic equation. The objective of this work is to compare the models and to establish the eventual superiority of a model on others
Ricaud, Sophie. "Recherche sur la physiologie des bourgeons latents des arbres : étude chez platanus acerifolia willd : contribution à l'étude de la physiologie de l'arbre en ville." Nancy 1, 1994. http://www.theses.fr/1994NAN10144.
Повний текст джерелаRchid, Halima. "Action du saccharose et du CO2 sur la croissance et la production de sapogénines stéroi͏̈diques des cultures cellulaires photomixotrophes et hétérotrophes de "Trigonella foenum-graecum L. "." Montpellier 2, 1993. http://www.theses.fr/1993MON20062.
Повний текст джерелаPodor, Myriam. "Effets de la sécheresse et de l'ozone sur le statut hydrique et la gestion du carbone chez le pin d'Alep (Pinus halepensis Mill. )." Vandoeuvre-les-Nancy, INPL, 1997. http://www.theses.fr/1997INPL040N.
Повний текст джерелаMaurice, Isabelle. "Mise en place du volume et dépôt de composés carbonés et azotés au cours de la croissance de la feuille de fétuque élevée (Festuca arundinacea Schreb. )." Vandoeuvre-les-Nancy, INPL, 1997. http://docnum.univ-lorraine.fr/public/INPL_T_1997_MAURICE_I.pdf.
Повний текст джерелаCarmeille, Mehdi. "Faciès, architecture et diagenèse des carbonates du Jurassique moyen et supérieur dans la chaîne du sud-ouest Gissar (Ouzbékistan)." Thesis, Bordeaux 3, 2018. http://www.theses.fr/2018BOR30053.
Повний текст джерелаThis transdisciplinary study including sedimentology, sequence stratigraphy, chemostratigraphy, and organic and inorganic geochemistry examines the Middle-Upper Jurassic carbonates series located in the southwestern Gissar range. These carbonates, also known as the Kugitang series, represent the most complete outcrop of the northern margin of the Amu-Darya Basin, a gas-producing province of Central Asia. Carbonate production begins in the late Early Callovian during a regional slowing of the tectonic subsidence, coeval with a climate warming. A major change in the carbonate production and platform configuration is recorded at the end of the Callovian: (i) a carbonate ramp with a well-contrasted proximal-distal gradient develops during the Lower to Middle or Upper Callovian. It is overlain by (ii) a vast low energy lagoon dominated by peritidal facies, probably protected by large reefs, during the Lower and Middle Oxfordian. The stratigraphic surface separating the two depositional sequences is associated with a hiatus (Upper Callovian-Lower Oxfordian) and interpreted as a regional exposure surface recording a sea-level drop caused by tectonics and/or climate. During the Middle Oxfordian, one or several intrashelf basins develop southwestwards of the studied carbonate platform. Laminated and nodular carbonates rich in organic matter predominate in these basins. They are interpreted to have formed through the mineralization of microbial mats colonizing the stratified, slightly hypersaline, anoxic to dysoxic basin floor. Large scale reefs may have favored the isolation of these basins. These deposits record the initiation of the tectonic isolation of the Amu Darya Basin, which culminates with the progradation of a large-scale sabkha and the deposition of a thick anhydrite and salt series. The comparison of stratigraphic series highlights common events in several basins of the northern Tethyan margin, but also with the Arabian Plate: initiation of the carbonate platform, carbon isotope excursions, age and depositional conditions of organic-matter rich rocks, etc. The petrography and geochemistry of carbonates reveal a complex diagenetic history. Some facies are strongly controlled by the sedimentary fabric. The diagenetic succession is tentatively linked with the stratigraphy and the subsidence history. Following deposition, the Kugitang series was buried at more than 2 km. Some cements are interpreted to have formed through the circulation of hot fluids in the rocks during the mesogenesis and possibly due to thermochemical sulfate reduction, especially in the Callovian Sequence. Finally, the high-resolution stratigraphy established in this study is used to help improving the prediction of carbonate reservoirs in the subsurface Amu Darya Basin
Tsafack-Menessong, Noëlline. "Abondance et origine trophique de la noctuelle de la tomate (Helicoverpa armigera) dans les paysages ruraux de production cotonnière au Nord Bénin." Thesis, Toulouse, INPT, 2014. http://www.theses.fr/2014INPT0053/document.
Повний текст джерелаThe development of strategies independent of pesticides is a fundamental objective for sustainable crop protection against pests as well as for maintaining of a healthy environment for human populations. The rationale of the research presented here was to improve our ability to control the cotton bollworm, Helicoverpa armigera by non-pesticide methods via habitat conservation. We analyzed the influence of agricultural practices and landscape composition and diversity on the abundance and trophic origin of H. armigera and assessed gossypol and tomatine in individual H. armigera as cotton and tomato biomarkers respectively. Gossypol was shown to be a stable cotton biomarker, even in adult H. armigera 12 days after emergence. In contrast, tomatine was only detected in larvae of H. armigera and not adults; thereby tomatine can not be considered as a marker of tomato plants. Subsequently, in north Benin, the abundance of H. armigera larvae and adults was monitored in cotton fields. We found a strong effect of agricultural practices on H. armigera larvae abundance. Delay sowing date and increase frequency of weeding reduced the abundance of H. armigera in cotton fields; whereas the proportion of cotton and tomato in the landscape increased. This study also highlights the role of the previous landcover in the infestation of a cotton field: A previous tomato landcover increased infestation three times more than a previous maize landcover. At nested scales ranging from 100 m, 250 m to 500 m, we studied the effects of landscape composition and diversity firstly on the abundance of adult H. armigera and secondly on their trophic origin. We found that, landscape diversity was the main factor that influenced both the abundance adult and their trophic origin at 500 m scale. Analyses of stables isotopes of Carbone showed that proportion of hosts plants with C3 photosynthetic pathway in the landscape was positively related to H. armigera moths with C3 trophic origin signal at 500 m scale. Only 10% of moths were positive to gossypol signal. The proportion of cotton in the landscape seems not important to explain the trophic origin of individual which were positive to gossypol signal. Therefore, for integrated management of H. armigera our results suggest it is necessary to consider the following agricultural practices and crop diversity regimes (in regard to the resource use strategies of this polyphagous pest). A tomato previous landcover should be avoid; shift sowing date between cotton fields, and have at less three manual weedings. In additional, we suggest employing maize around cotton fields rather than other crops
MANLAY, Raphaël. "Dynamique de la matière organique à l'échelle d'un terroir agro-pastoral de savane ouest-africaine (sud-Sénégal)." Phd thesis, ENGREF (AgroParisTech), 2000. http://tel.archives-ouvertes.fr/tel-00005770.
Повний текст джерелаLe terroir choisi était organisé en auréoles, avec une intensification croissante des pratiques de la périphérie (auréole de brousse) vers le village (champs de case).
Les stocks dans le système sol-plante étaient de 54,7 tC, 2,63 tN et 43,5 kgP ha-1 dans les jachères âgées, soit des croîts respectifs de 97, 29 et 251 % par rapport aux cultures de brousse (l'augmentation ayant lieu essentiellement dans la biomasse végétale). Les stocks mesurés dans le sol des champs de case étaient supérieurs à ceux des cultures de brousse, essentiellement dans l'horizon 0-10 cm. Cependant, la faible réponse globale des stocks de carbone des sols sableux à la jachère et à la fumure ne peut être interprétée qu'en réévaluant le rôle bio-thermodynamique joué par le carbone dans l'intégrité des agroécosystèmes locaux.
Les stocks moyens sur le terroir contrôlables par l'homme furent estimés à 29,7 tC, 1,52 tN and 28,6 kgP ha-1 en 1997. Le carbone était stocké surtout dans le sol. Elevage, récoltes et collecte de bois ont représenté respectivement 59, 27 et 14 % des prélèvements de carbone dans le terroir. Grâce à eux, des flux importants de carbone ont été établis vers les champs de case (3,8 tC ha-1 an-1), et les pertes minérales globales ont été estimées à 4 kgN et 1 kgP ha-1 an-1. Le terroir était donc proche de l'équilibre minéral.
Mais selon la dynamique démographique actuelle, la perte de carbone pourrait atteindre 0,38 tC ha-1 an-1, et la demande en carbone doubler durant les 30 prochaines années. Sans intensification des pratiques, ceci remettrait en cause la viabilité du système.
Rivalland, Vincent. "Amélioration et validation du modèle de fonctionnement de la végétation ISBA-A-gs : stress hydrique et flux de CO2." Toulouse 3, 2003. https://tel.archives-ouvertes.fr/tel-00009717.
Повний текст джерелаVoisin, Anne-Sophie. "Etude du fonctionnement des racines nodulées du pois (Pisum sativum L. ) en relation avec la disponibilité en nitrates du sol, les flux de carbone au sein de la plante et la phénologie : croissance des racines nodulées et activité fixatrice des nodosités." Dijon, 2002. http://www.theses.fr/2002DIJOS005.
Повний текст джерелаBrunel, Jean-Evrard. "Influence de l'endommagement sur la rupture de plaques composites en présence de surcontraintes." Paris 13, 1989. http://www.theses.fr/1989PA132008.
Повний текст джерелаPincebourde, Sylvain. "Biophysique environnementale des insectes endophytes." Phd thesis, Université François Rabelais - Tours, 2005. http://tel.archives-ouvertes.fr/tel-00108243.
Повний текст джерелаDes mesures de spectrométrie optique ont démontré que la larve modifie profondément les propriétés optiques de la surface de la feuille au cours de son nourrissage. La structure mine absorbe bien plus de radiations dans le proche infrarouge que les tissus foliaires intacts. De plus, une quantité importante de radiations est transmise à l'intérieur de la mine par le tégument supérieur dans les zones prélevées par la larve. Ces radiations induisent une élévation importante de son activité respiratoire (rejet de CO2). En utilisant un analyseur de gaz par infrarouge, nous avons pu montrer par ailleurs que les stomates localisés dans le tégument inférieur de la mine réagissent à la présence de la larve en se fermant. Un modèle de diffusion de CO2 a révélé que les stomates réagissent directement aux variations d'émission de CO2 par la larve. Le budget thermique de la mine a ensuite été modélisé. Le modèle permet de prédire la température à l'intérieur de la mine à partir des modifications des propriétés optiques et de la physiologie des stomates, et à partir des variables climatiques. Ce modèle biophysique a été validé en comparant ses prédictions avec des mesures expérimentales de température de mines réalisées en environnement contrôlé. Le modèle à une précision de 0,8 °C dans l'intervalle de 12 °C à 42 °C. Le modèle prédit un important excès de température dans la mine, atteignant 10 °C au dessus de la température de l'air et 5 °C au dessus de la température des tissus foliaires intacts. Les deux types de modifications – propriétés optiques et comportement stomatiques – ont un impact équivalent sur l'excès de température. Cette approche démontre clairement que la larve contrôle son environnement physique en modifiant son environnement. Nos résultats sont finalement discutés dans une perspective d'écologie évolutive. Plus particulièrement, le rôle du microclimat des insectes endophages dans l'évolution de leurs sensibilités thermiques et de celles de leurs parasitoïdes est détaillé.
Shahzad, Tanvir. "Role of plant rhizosphere across multiple species, grassland management and temperature on microbial communities and long term soil organic matter dynamics." Phd thesis, AgroParisTech, 2012. http://pastel.archives-ouvertes.fr/pastel-00772440.
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