Spelling suggestions: "subject:"treatment""
1 |
Problematika diskriminace v pracovním procesu / The issue of discrimination in the work procedureVolná, Michaela January 2011 (has links)
The theme of the thesis is the current and debated issue of discrimination in the wok procedure. Although the Czech Republic has already implemented the applicable European legislative requirements in its national law and the concept of non-discrimination is - from the labor-law perspective - sufficient, frequent cases of differential treatment and discrimination still exist. The thesis focuses on equal treatment and discrimination in both selected Czech legislative documents and the legislation of the European Community. It focuses in more detail on gender discrimination (the most common form of discrimination) followed by the institutional security of equal treatment, difference in pay between men and women, labor market segregation, the issue of reintegration of women and men into the workplace after maternity or parental leave, representation of women in managerial positions, discrimination against elderly women and sexual harassment in the work environment. Part of the thesis also focuses on possible approaches to solve these problems such as harmonization between work and private life, the company's social responsibility, and Diversity and Age Management.
|
2 |
QUALITATIVE AND QUANTITATIVE PROCEDURE FOR UNCERTAINTY ANALYSIS IN LIFE CYCLE ASSESSMENT OF WASTEWATER SOLIDS TREATMENT PROCESSESAlyaseri, Isam 01 May 2014 (has links)
In order to perform the environmental analysis and find the best management in the wastewater treatment processes using life cycle assessment (LCA) method, uncertainty in LCA has to be evaluated. A qualitative and quantitative procedure was constructed to deal with uncertainty for the wastewater treatment LCA studies during the inventory and analysis stages. The qualitative steps in the procedure include setting rules for the inclusion of inputs and outputs in the life cycle inventory (LCI), setting rules for the proper collection of data, identifying and conducting data collection analysis for the significant contributors in the model, evaluating data quality indicators, selecting the proper life cycle impact assessment (LCIA) method, evaluating the uncertainty in the model through different cultural perspectives, and comparing with other LCIA methods. The quantitative steps in the procedure include assigning the best guess value and the proper distribution for each input or output in the model, calculating the uncertainty for those inputs or outputs based on data characteristics and the data quality indicators, and finally using probabilistic analysis (Monte Carlo simulation) to estimate uncertainty in the outcomes. Environmental burdens from the solids handling unit at Bissell Point Wastewater Treatment Plant (BPWWTP) in Saint Louis, Missouri was analyzed. Plant specific data plus literature data were used to build an input-output model. Environmental performance of an existing treatment scenario (dewatering-multiple hearth incineration-ash to landfill) was analyzed. To improve the environmental performance, two alternative scenarios (fluid bed incineration and anaerobic digestion) were proposed, constructed, and evaluated. System boundaries were set to include the construction, operation and dismantling phases. The impact assessment method chosen was Eco-indicator 99 and the impact categories were: carcinogenicity, respiratory organics and inorganics, climate change, radiation, ozone depletion, ecotoxicity, acidification-eutrophication, and minerals and fossil fuels depletion. Analysis of the existing scenario shows that most of the impacts came from the operation phase on the categories related to fossil fuels depletion, respiratory inorganics, and carcinogens due to energy consumed and emissions from incineration. The proposed alternatives showed better performance than the existing treatment. Fluid bed incineration had better performance than anaerobic digestion. Uncertainty analysis showed there is 57.6% possibility to have less impact on the environment when using fluid bed incineration than the anaerobic digestion. Based on single scores ranking in the Eco-indicator 99 method, the environmental impact order is: multiple hearth incineration > anaerobic digestion > fluid bed incineration. This order was the same for the three model perspectives in the Eco-indicator 99 method and when using other LCIA methods (Eco-point 97 and CML 2000). The study showed that the incorporation of qualitative/quantitative uncertainty analysis into LCA gave more information than the deterministic LCA and can strengthen the LCA study. The procedure tested in this study showed that Monte Carlo simulation can be used in quantifying uncertainty in the wastewater treatment studies. The procedure can be used to analyze the performance of other treatment options. Although the analysis in different perspectives and different LCIA methods did not impact the order of the scenarios, it showed a possibility of variation in the final outcomes of some categories. The study showed the importance of providing decision makers with the best and worst possible outcomes in any LCA study and informing them about the perspectives and assumptions used in the assessment. Monte Carlo simulation is able to perform uncertainty analysis in the comparative LCA only between two products or scenarios based on the (A-B) approach due to the overlapping between the probability distributions of the outcomes. It is recommended to modify it to include more than two scenarios.
|
3 |
The effect of Crataegus oxyacantha Ø on homocysteine levels in malesJoubert, Petrie 19 July 2012 (has links)
M.Tech. / Cardiovascular disease and its complications accounts for about half of all deaths worldwide. As conventional risk factors do not successfully explain all of these cases, homocysteine (Hey) appears to be a new and promising field to investigate as an accompanying risk factor for the development of cardiovascular disease (Stanger et al., 2004). Hyperhomocysteinaemia, or elevated Hey levels, have been shown to be directly linked to the development of cardiovascular disease (Wald and Morris, 2002). Crataegus oxyaeantha Mother Tincture (0) has been used over centuries for various cardiovascular disease conditions and is considered to have cardio-protective properties (Rose and Treadway, 1999), however its effect on homocysteine levels has not been researched. The atm of this double-blind placebo-controlled study was to determine the effect of homoeopathically prepared Crataegus oxyaeantha (J on Hey levels in males aged 25-35 years of age by measuring Hey levels in the blood over a three week period. Participants attended an initial consultation where the procedure of the research was discussed, a short medical history was taken, and a full cardiovascular examination together with vital signs was assessed. Thereafter a pathology laboratory (Lancet laboratories) measured Hey levels of the participants. Those participants that qualified for the study were divided into two groups of fifteen. The experimental group received a 25mL bottle of Crataegus oxyaeantha 0 and the placebo group received a 25mL bottle of alcohol identical in appearance and taste. Participants were informed not to make any substantial changes to their diet and lifestyle. After three weeks a second Hey test was completed and a follow up consultation was scheduled. Collected data was statistically analyzed and a Chi Square goodness of fit test was utilized to determine if there was any significant decrease in Hey levels in the participating individuals. Preliminary findings suggest that Crataegus oxyaeantha (J was not effective in reducing plasma Hey levels in adult males with Hey levels of 6.3 mmoVL and higher, however more research over an extended period of time is needed to confirm these findings.
|
4 |
Amélioration d'un composé actif contre la maladie de Huntington / Improvement of a compound active against Huntington’s diseaseMarelli, Cecilia 18 December 2015 (has links)
Le sujet de cette thèse est la poursuite de la caractérisation et du développement à fins thérapeutiques du peptide P42 dans la maladie d’Huntington (MH). Ce peptide a été précédemment identifié dans l’équipe dirigée par Florence Maschat et est capable de réduire la présence d’agrégats dans différents modèles cellulaires, mais aussi de Drosophile et murins de maladie d’Huntington. P42 est aussi capable de prévenir la dégénérescence neuronale et les altérations du transport axonal dans des tests effectués chez la drosophile (Arribat et al. 2013). Enfin les anomalies motrices, la perte de poids, et l’atrophie cérébrale sont restituées in vivo dans des souris R6/2 traitées par P42. Dans ce cas, P42 a été conjugué au peptide de transduction TAT, dérivé de VIH, et a été inséré dans des microémulsions, permettant des administrations répétées du peptide par voie intra-muqueuse, protégeant le peptide jusqu’à son arrivée au cerveau et facilitant sa diffusion au travers des membranes et la barrière hémato-encéphalique (Arribat et al., 2014). L’efficacité de ce peptide a ainsi été montrée après administration dans une phase pré-symptomatique ; toutefois, des résultats non publiés suggèrent également une efficacité partielle au niveau post-symptomatique. Ainsi ce peptide agirait à travers l’inhibition de l’agrégation en interagissant avec la protéine Htt dans sa partie N-terminale, et notamment au niveau de la partie N17. Des résultats préliminaires suggèrent également que, en tant que partie physiologiquement présente dans la protéine Htt, P42 pourrait avoir un rôle bénéfique et physiologique, notamment au niveau du transport axonal, sur le niveau d’expression du Brain nerve factor (BDNF) et sur l’activité neuronale. Mon travail de thèse se compose d’une part d’un travail de laboratoire, et d’autre part d’un travail de documentation. Le travail de laboratoire a été conduit sur le modèle Drosophile. Dans une première partie j’ai essayé de mieux caractériser l’efficacité de P42TAT par rapport à P42 dans l’inhibition des agrégats dans les glandes salivaires et dans la protection de la dégénérescence de l’œil. Notamment, j’ai testé l’efficacité de l’administration orale de P42TAT sur la réduction des agrégats dans les glandes salivaires. Dans une deuxième partie j’ai contribué à évaluer l’efficacité d’un fragment plus court de P42, P42B ; ce fragment de 14 aa initialement identifié par des études de dégradation de P42TAT dans des extraits de cerveau par la technique MALDI est retrouvé après 3 h et pourrait donc être une partie active, suffisante pour l’efficacité du peptide. Dans une troisième partie j’ai contribué à des études visant à étudier le rôle physiologique de P42 dans le transport axonal. Le travail de documentation a été finalisé par la soumission d’un dossier à l’agence européenne pour la médecine (EMEA), qui a permis d’obtenir la reconnaissance de P42 en tant que médicament orphelin pour la MH. Ce résultat est particulièrement important et pourrait être un premier pas vers le développement clinique de ce peptide. En effet aucun traitement curatif n’existe à ce jour pour la MH et la possibilité de réaliser des tests pré-symptomatiques permet de disposer d’une fenêtre unique pour une intervention thérapeutique précoce. De plus, au cours de ces dernières années, des études cliniques de suivi de sujets pré-symptomatiques et symptomatiques ont été menées, (études PREDICT-HD et TRACK-HD), qui ont conduit à l’identification de bio-marqueurs, notamment d’imagerie, capables de suivre l’évolution de la maladie, dès un stade pré-symptomatique, utilisables pour évaluer de façon objective l’efficacité d’un traitement, si disponible. Enfin, l’ensemble de ce travail m’a permis d’acquérir une expertise et de mener une réflexion au sein du laboratoire sur l’utilisation des peptides à des fins thérapeutiques dans la maladie d’Huntington, avec la production d’un papier de revue sur le sujet, soumis dans une revue internationale. / The subject of this thesis is the further characterization and development in therapeutic purpose of P42 peptide in Huntington's disease. This peptide was previously identified in the team led by Florence Maschat and it showed be able to reduce the presence of aggregates in different cell models, but also Drosophila and murine (mouse R6 / 2) of Huntington's disease. P42 is also able to prevent neuronal degeneration and alteration of axonal transport in the tests performed in Drosophila (Arribat et al. 2013). Finally the motor abnormalities, weight loss and brain atrophy are ameliorated in vivo in R6 / 2 mice treated with P42. In the latter case, P42 was conjugated to TAT transducing peptide, derived from HIV, and was inserted into microemulsions, with the purpose of enabling repeated administrations of the peptide by intra-mucosal route, protect the peptide until his arrival to the brain and facilitate its diffusion through the membranes and the blood-brain barrier (Arribat et al. 2014). The efficacy of this peptide has been shown following administration in a pre-symptomatic stage; however, unpublished results also suggest a partial efficacy in post-symptomatic level. Thus this peptide would be through the inhibition of aggregation by interacting with Htt in its N-terminal part, and in particular at the N17 part. Preliminary results also suggest that, as part physiologically present in the Htt protein, P42 and could have a beneficial physiological role, particularly in terms of axonal transport, level of expression of Brain nerve factor (BDNF), and neuronal activity.My thesis consists of a hand on a laboratory work, and secondly on a work documentation. The laboratory work was conducted using the Drosophila model. In the first part I tried to better characterize the effectiveness of P42TAT and compare it to that of P42 in inhibiting aggregates in the salivary glands and in the protection of the degeneration of the eye. In particular, I tested the efficacy of oral administration of the peptide P42TAT on reducing aggregates in the salivary glands. In the second part I helped evaluate the effectiveness of a shorter fragment of P42, P42B; this peptide was first identified through studies on the degradation of P42TAT in extracts of brain by MALDI; this fragment of 14 aa was found after 3 h and therefore could be an active portion, sufficient for the effectiveness of the peptide. In the third part I contributed to studies to study the physiological role of P42 in axonal transport.The documentation work was finalized at the submission of a dossier to the European Agency for medicine (EMEA), in order to obtain for P42 the label of orphan drug for Huntington's disease. This result is particularly important and could be a first step in the clinical development of this peptide. Indeed no curative treatment exists to date for Huntington's disease and the ability to perform pre-symptomatic tests can provide a single window for early therapeutic intervention. Moreover, in recent years, clinical studies monitoring symptomatic and pre-symptomatic patients were conducted (PREDICT-HD studies and TRACK-HD), which led to the identification of biomarkers, in particular of imaging, able to follow the evolution of the disease, already at a pre-symptomatic stage, be used to objectively evaluate the effectiveness of treatment if available. Finally, all of this work has allowed me to gain expertise and to reflect on the use of peptides for therapeutic purposes in Huntington's disease, with the production of paper review on the subject submitted to an international journal.
|
5 |
Okolnosti vylučující protiprávnost při poskytování zdravotních služeb. / Criminal defences regarding the provision of health care services.Zaoralová, Petra January 2015 (has links)
The criminal defences are of a very high importance especially in the context of health care services. They set the conditions under which health care services may be provided without any criminal sanction. Legislation regarding the criminal defences has been under constant development and the topic remains very actual nowadays. The thesis is divided into five chapters. First chapter introduces the reader the issue and explains the importance of dealing with criminal defences. Second chapter concerns general aspects of criminal defences and is divided into three parts. First of them deals with the term of unlawfulness, since the circumstances which are subject to this research, exclude the unlawfulness. Next part is dedicated to the legal regulation of defences and relations between them. Last part of first chapter explains philosophical and moral principles of acting within the scope of defences. Such principles are introduced both on a theoretical level and practical cases. Third chapter deals with particular criminal defences, including the defences which are not explicitly stated in the criminal code, and thoroughly explains issues related to them in its five parts. First part offers detailed overview of conditions of necessity and its impact on providing of health care services. Attention is paid also...
|
6 |
Étude de l'origine de défauts détectés dans des pièces en alliage d'aluminium de la série 7XXX destinées à l'industrie aéronautique / Study of the origin of defects detected in 7XXX aluminum alloy components for aeronautical applicationsAgouti, Siham 13 December 2012 (has links)
Les travaux de cette thèse s'insèrent dans le cadre de l'étude de défauts détectés par contrôle ultrason dans des pièces forgées en alliage d'aluminium destinées à l'industrie aéronautique.Cette étude a été menée sur deux pièces produites par Aubert&Duval en alliage d'aluminium 7050 fourni par Constellium. Ces pièces ont été sélectionnées sur base d'une étude statistique de l'occurrence des défauts sur cinq années de production industrielle. L'une présente un taux de rebut important du fait de ces défauts, l'autre un taux de rebut quasiment nul, bien qu'elles soient produites avec le même matériau.L'étude de l'origine des défauts a été construite autour de deux axes de recherche:• Axe thermomécanique : formation des défauts pendant la mise en forme par endommagement ductile à chaud.• Axe matériau : caractérisation des défauts préexistants dans le matériau après son élaboration et non refermés pendant la mise en forme.L'axe thermomécanique est basé sur la simulation numérique des gammes de mise en forme des pièces industrielles à l'aide du logiciel Forge® 2009. Le deuxième axe est articulé autour de la caractérisation de l'état de porosité dans un matériau modèle présentant une teneur en hydrogène élevée induisant un taux de porosité plus important que le matériau sain utilisé industriellement. De petits lopins de ce matériau modèle ont été soumis à une campagne de compression alternée simulant le forgeage industriel. La campagne de compression a été conçue par simulation numérique afin de reproduire les conditions thermomécaniques industrielles. Deux techniques de caractérisation complémentaires ont été mises en œuvre pour suivre l'évolution de la porosité : détection indirecte par contrôle ultrason à haute résolution spatiale et observations directes par microscopie électronique à balayage. Une méthode d'analyse quantitative des signaux ultrasonores a été mise au point pour ce travail.La comparaison par simulation numérique du procédé de matriçage des deux pièces industrielles étudiées a permis d'écarter l'hypothèse de la création des défauts par endommagement ductile à chaud. Lors du matriçage, la matière est soumise à des chargements globalement compressifs, et le risque d'endommagement est par conséquent très faible. De plus, comme observé lors de la caractérisation des défauts industriels, les défauts présentent un fond lisse, similaire au fond lisse observé sur les rares porosités présentes dans le matériau industriel à l'état brut d'élaboration. Le même type de fond lisse caractérise également les porosités présentes dans le matériau modèle. Cette observation favorise l'hypothèse de défauts provenant d'un défaut préexistant dans le matériau initial (en l'occurrence à partir d'une porosité). Cette hypothèse est par ailleurs cohérente avec le comportement des porosités lors de la simulation du forgeage sur petits lopins du matériau modèle.Les résultats de cette étude montrent en effet que les porosités ont tendance à s'aplatir et à se refermer pendant la déformation plastique à chaud, sans forcément cicatriser. Les faciès de rupture d'échantillons soumis à de fortes déformations cumulées et ne donnant plus de réponse ultrasonore significative continuent en effet de présenter de petites plages à fond lisse qui témoignent d'une cicatrisation incomplète. Le traitement thermique semble en outre favoriser la réouverture des porosités non cicatrisées (zones lisses) pendant la déformation et leur élargissement (zones ductiles). / The thesis project aims to study the origin of defects detected in 7XXX aluminium alloy components for aeronautical applications.This work was conducted on two different components (A and B) produced by Aubert&Duval using 7050 aluminium alloy ingots produced by Constellium. The choice of these two components is based on a five year industrial production statistical analysis. Component A has a much higher defect rate compared to component B, even though they are produced from the same ingots.This work was conducted according to two research axis:• Thermo-mechanical axis : defects occurred during the material forming as a result of ductile hot damage• Material axis: defects resulted from a pre-existent defect in the raw material that was not closed during forming.The thermo-mechanical axis is based on numerical simulations of the component's forming processes using the Forge® 2009 software. The material axis is based on the experimental characterization of porosity in a model material with high hydrogen content and thus a higher pore density than the industrial material. Small samples of the model material were experimentally forged using an alternating compression test that was designed and developed from the industrial forging process. Theses samples were characterized to describe pore evolution during hot deformation, by the combination of two characterization techniques: High Resolution Ultrasound Control (HRUS) and Scanning Electron Microscope (SEM) observations on 2D sections and fracture surfaces. An ultrasound signal processing technique was also developed in order to quantitatively compare two different deformation states using ultrasound control.The results of the numerical simulation of A and B component stamping process showed that the detected defects could not occur by ductile hot damage. Indeed, the stamping process is purely compressive and damage risks are thus very low. Moreover, the defect experimental characterization showed the presence of smooth surface areas very similar to the surface aspect of the rare observed porosity in the raw material. The same smooth aspect characterized the porosity observed in the model material. These results lead to the hypothesis that the detected defects could occur from a pre-existent defect (porosity more precisely) in the raw material. This hypothesis is consistent with the pore behaviour during the experimental hot forging of the model material.The hot forging experiment conducted on the model material, showed that pores tend to flatten as plastic strain increases. SEM observations on rupture surfaces from the highest plastic strain showed the presence of small smooth aspect areas. These areas confirm that some pores are not completely healed during deformation even though the correspondent ultrasound signal is very low. During heat treatment, unhealed pores after deformation seem to be reopened (smooth aspect surface areas) and expanded (ductile areas).
|
7 |
Role sestry v edukaci pacienta před anestezií u operačních výkonů v ortopedii / The role of nurses in patient education prior to anesthesia for surgical procedures in orthopedicsSlouková, Michaela January 2016 (has links)
The thesis is focused on the role of nurse in patient education prior anaesthesia in surgical procedures in orthopaedic. Description of this role is based on the experience at the orthopaedic clinic and problems related to it are seen in the results of survey. The aim was to assess the level and effectiveness of patient education done by nurse before anaesthesia, measure the level of satisfaction and patient awareness before surgery, assess the quality and content of education provided by nurse and identify the current competencies of nurses in patient education before anaesthesia. Data for the research survey were obtained through two questionnaires designed for nurses working at the orthopaedic clinic and for patients who have undergone scheduled intervention in this clinic. The most important finding of the research results was crossing the competencies of nurses in the preoperative patient education because the lack of visits by anaesthesiologist. Based on what I studied in the available literature and the research results, in the discussion I am presenting proposals for solutions of this situation and I suggest active offering of the information material to patient during admission, the creation of improved education material for preoperative preparation, using of different teaching methods...
|
8 |
Développement de matrices alimentaires permettant de protéger des substances actives lors des traitements thermiques / Development of food matrices to protect active substances during heat treatmentsNikolova, Yoana 11 July 2017 (has links)
Les produits déshydratés permettent d’optimiser la conservation et le transport des aliments. Les poudres alimentaires distribuées au consommateur affichent des garanties nutritionnelles en termes d’apports qualitatif et quantitatif. Cependant, l’apport nutritionnel du produit après reconstitution et cuisson, n’est pas garanti. Ce travail se concentre sur l’évaluation des pertes en vitamines dues aux procédés de transformation alimentaire en lien avec l’effet de la matrice alimentaire. Ces pertes mesurées après le traitement thermique ne sont pas négligeables, rendant l’encapsulation nécessaire pour répondre à l’objectif de la thèse de garantir une teneur en vitamines suffisante après reconstitution et traitement thermique du produit alimentaire déshydraté. Différentes matrices ont été testées à l’échelle laboratoire et industrielle. Parmi ces matrices, certaines comme les protéines laitières et l’amidon se sont avérées très intéressants et ont permis la préservation de la vitamine C du traitement thermique. Pour finaliser l’étude, il a été indispensable de prendre en compte le stockage des poudres de la vitamine C encapsulée avant et après leur commercialisation. Pour assurer leur teneur suffisante en vitamine C lors ce stockage, un vieillissement accéléré a été effectué. Cette thèse a permis d’apporter des réponses concrètes au problème industriel posé, qui était de garantir la teneur en vitamine C des produits commercialisés après reconstitution et traitement thermique / Dehydrated products make it possible to optimize the storage and transport of food products. Food powder mixes distributed to the consumer display nutritional guarantees in terms of qualitative and quantitative inputs. However, the nutritional value of the product after reconstitution and cooking, is not guaranteed. This PhD work focuses on the evaluation of vitamins losses due to food processing in relation to the effect of the food matrix. Losses measured after the heat treatment were not negligible, making the encapsulation necessary to meet the objective of the thesis to guarantee a sufficient vitamins content after reconstitution and heat treatment of the dehydrated food product. Different matrices have been tested at the laboratory scale and industrial scales. Some of these matrices, such as dairy proteins and starch, have proved to be very interesting and allowed the preservation of vitamin C during heat treatment. To finalize the study, it was essential to take into account that the vitamin C-encapsulating powders will be stored before and after their distribution. To ensure that they maintain a sufficient vitamin C content during storage, accelerated aging has been carried out. Thus this thesis made it possible to provide concrete answers to the posed industrial problem, which was to guarantee the vitamin C content of the commercial products after reconstitution and heat treatment
|
9 |
Développement de nouveaux traitements non-biocides de protection du bois basés sur la formation in situ de polyesters bio-sourcés / Development of new non-biocide wood protection treatments based on the in situ formation of bio-based polyestersL'hostis, Clément 20 December 2017 (has links)
Afin de garantir la pérennité des ouvrages en bois, ce matériau naturellement dégradable par de nombreux organismes biologiques, doit généralement subir des traitements de protection. L'usage de produits biocides est actuellement la solution la plus employée pour conférer au bois une durabilité supplémentaire. Cependant, devant la problématique environnementale qu'ils soulèvent, l'utilisation de substances biocides est de plus en plus limitée par la réglementation. Des alternatives à l'emploi de biocides ont été développées pour augmenter la durabilité du bois : le traitement thermique et la modification chimique. Le traitement thermique consiste en la dégradation contrôlée des macromolécules du bois, pour le rendre plus hydrophobe, plus stable dimensionnellement et plus résistant à l'attaque des champignons de dégradation. Cependant ce type de traitement affaiblit les propriétés mécaniques du matériau. La modification chimique consiste en l'imprégnation de molécules au sein du matériau, lesquelles vont ensuite réagir avec les constituants du bois pour modifier sa structure chimique. Au cours de cette thèse, des traitements à base de molécules bio-sourcées ont été développés. Ainsi, les traitements opérés sur du hêtre, essence particulièrement sensible à la biodégradation et dimensionnellement instable, ont permis d'améliorer sensiblement ces propriétés. La formation in situ de polyesters de glycérol et de différents acides carboxyliques engendre un matériau plus résistant mécaniquement que les bois traités thermiquement, tout en apportant également une stabilité dimensionnelle et une durabilité renforcées. Les différents acides carboxyliques employés ont, de plus, induit des comportements différents au regard des différentes propriétés étudiées, mettant en lumière l'importance de la structure chimique des réactifs employés. Le traitement le plus prometteur a fait l'objet d'une étude économique montrant la viabilité de l'industrialisation du procédé, qui permettrait alors l'obtention d'un bois modifié utilisable en classe d'emploi 3, tout en valorisant une ressource abondante et sous-exploitée / In order to guarantee the sustainability of structure made of wood, this material, which is naturally degradable by many biological organisms, must generally undergo protection treatments. The use of biocidal products is currently the most employed solution to confer the wood additional durability. However, facing of the environmental problem they raise, their use tends to be increasingly limited by regulation. Alternatives to the use of biocides have been developed to increase the durability of wood: heat treatment and chemical modification. Heat treatment consists of the controlled degradation of wood macromolecules to make it more hydrophobic and therefore more dimensionally stable and more resistant to the attack of the fungi of degradation, but weakens its mechanical properties. Chemical modification involves the impregnation of molecules within the material, which then react with the constituents of the wood to modify its chemical structure. During this thesis, treatments based on bio-based molecules have been developed. Thus, the treatments carried out on beech, a species which is particularly sensitive to biodegradation and dimensionally unstable, have made possible to improve substantially these properties. The in situ formation of polyesters of glycerol and various carboxylic acids produces a material more resistant mechanically than thermally treated wood, while also providing enhanced dimensional stability and durability. The various carboxylic acids employed have also induced different behavior with regard to the various properties studied, highlighting the importance of the chemical structure of the reagents employed. The most promising treatment was the subject of an economic study showing the viability of the industrialization of the process, which would then make it possible to produce a modified wood that can be used in use class 3, while enhancing an abundant under-exploited resource
|
10 |
Photoluminescence and Extended X-ray Absorption Fine Structure Studies on CdTe MaterialLiu, Xiangxin 20 June 2006 (has links)
No description available.
|
Page generated in 0.0837 seconds