Diss. (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 4 uppsatser.

Made available in DSpace on 2016-06-02T19:32:07Z (GMT). No. of bitstreams: 1 5200.pdf: 2330287 bytes, checksum: 40cc22959878b0557c657a05a39a2e38 (MD5) Previous issue date: 2013-03-15 / Universidade Federal de Sao Carlos / Due to the high rates of environmental degradation and their consequences to the population, environmental recovery in many areas is an urgent need. Recovering degraded areas may be done by using several techniques alone or in combination. The traditional recovery system by means of seedling planting is expensive and has limited guarantee of germination using no-tillage sowing. Therefore, this study tested the viability of experimentally growing seedlings from seven native tree species without them suffering significant changes, after storing the sprouts in cold chambers for periods ranging from 7 to 28 days. The results showed that it is possible to delay the growing of radicles in seedlings stored in cold chambers (15°C) when compared to seedlings stored in germinator (25°C). In four out of seven species (Marlierea eugeniopsoides, Cordia americana, Cedrela fissilis e Hymenaea courbaril) stored for 14 days in cold chambers, the seedlings survival rates were higher than 77% 60 days after they were seeded in the nursery containers. This survival rate was similar to the rate of seedlings not stored in cold chambers. In three species (Marlierea eugeniopsoides, Luehea grandiflora e Hymenaea courbaril) stored for 21 days the survival rates were higher than 75%. The species Marlierea eugeniopsoides did not show significant survival changes even after storage in cold chamber for 28 days. / As elevadas taxas de degradação ambiental e as consequências deste processo para a população trouxeram à tona a urgência na recuperação ambiental dessas áreas. A restauração de uma área degradada pode ser realizada por meio de diversas técnicas utilizadas isoladamente ou em conjunto. Tendo em vista o elevado custo demonstrado no sistema tradicional de restauração de áreas degradadas, através do plantio de mudas, e às limitações de garantia de germinação de sementes utilizando-se a técnica de semeadura direta, este estudo avaliou se seria possível, experimentalmente, o crescimento e o desenvolvimento de plântulas de sete espécies arbóreas nativas, sem sofrerem alterações significativas, após suas sementes, recém-germinadas, serem armazenadas por períodos que variavam de 7 a 28 dias em câmara fria. Os resultados indicam que é possível retardar o crescimento das radículas de plântulas submetidas ao armazenamento em câmera fria (15 °C), quando comparado com plântulas armazenadas em germinador (25 °C). Das sete espécies estudadas, quatro (Marlierea eugeniopsoides, Cordia americana, Cedrela fissilis e Hymenaea courbaril), apresentaram uma taxa de sobrevivência das plântulas, que permaneceram armazenadas por 14 dias em câmara fria, maior que 77 %, após 60 dias que foram plantadas em tubetes no viveiro, uma taxa de sobrevivência equivalente ao das plântulas não submetidas à câmara fria. Três espécies (Marlierea eugeniopsoides, Luehea grandiflora e Hymenaea courbaril) apresentaram taxas de sobrevivência de suas plântulas submetidas à câmara fria por 21 dias superior a 75%. A espécie Marlierea eugeniopsoides não apresentou variação estatisticamente significativa da taxa de sobrevivência de suas plântulas, mesmo quando armazenadas por 28 dias em câmara fria.

Cette thèse concerne la stabilisation exponentielle de systèmes commandés en réseaux (NCS en anglais) par retour de sortie. Les solutions proposées reposent sur un observateur distant et capable d’estimer l’état présent du processus malgré les différents retards générés par la présence du réseau. Le premier chapitre présente le contexte général des NCS et décrit plus particulièrement le problème étudié. Le chapitre suivant propose une architecture informatique permettant de réaliser un retour d’état distant basé sur une structure d’observateur. Deux autres chapitres proposent ensuite la synthèse d’un couple loi de commande / observateur garantissant des performances de convergence exponentielle. Les conditions correspondantes s’écrivent sous forme d’inégalités matricielles linéaires (LMI en anglais) et permettent donc une optimisation. Ces conditions sont basées sur la méthode des fonctionnelles de Lyapunov-Krasovskii et des résultats originaux sont proposés. Une première synthèse peut être effectuée globalement, une seconde permet d’adapter les performances dynamiques à la qualité de service disponible à chaque instant. La seconde approche fait intervenir des résultats originaux sur les systèmes à retards et à commutations. Dans un dernier chapitre, nous proposons une solution complètement asynchrone (gérée par événements). Dans ce cas, le problème des pertes de paquets devient crucial et nous y apportant une réponse. L’ensemble des résultats est confirmé par des expérimentations mises au point dans le cadre de ce travail, et correspondant à un robot léger commandé en temps réel à 40km de distance par Internet / This PhD thesis is dedicated to the exponential output stabilization of linear NCS (Networked Control Systems). The studied solution is based on a remote observer which is able to estimate the present state of the plant despite the various network induced delays. These last are present in both the control and the measurement channels.The first chapter describes the problem and gives a survey on the NCS. The next chapter proposes a computer structure which realizes the remote, observer-based, state feedback controller. The following two chapters propose LMI conditions (Linear Matrix Inequalities) for the design of the observer-based remote controller. The second method of Lyapunov is used with the most up-to-date Lyapunov-Krasovskii functionals. The main objective of the design is to guarantee some performances expressed in the form of exponential stability. Then some enhancements of the control strategy are given. It consists in taking into account the Quality of Service (QoS) in the controller to get better guaranteed performances. The last contribution of this work is to consider the overall system as an event-driven system. It allows one to consider packet dropout problems in the network.The effectiveness of all presented results is demonstrated by real experiments implemented on a light robot controlled over the Internet

Hormesis is a dose response phenomenon where low doses of a stress bring about a positive response in the organism undergoing treatment. UV-C hormesis has been known for over three decades and has a broad range of benefits on postharvest produce. Benefits include increased nutritional content, delayed chlorophyll degradation and disease resistance. The beneficial effects have been observed on many varieties of fresh produce including climacteric and non-climacteric fruit, tubers, salads and brassicas. The majority of previous studies have used low-intensity (LIUV) UV-C sources. LIUV sources require lengthy treatment times, which are in the region of 6 minutes for tomato fruit. This has, in part, prevented the commercial application of this technique. High-intensity, pulsed polychromatic light (HIPPL) sources, however, have recently been developed. HIPPL sources may have the potential to drastically reduce treatment times and increase their commercial viability. It was shown, here, that the use of HIPPL can control disease (reduce disease progression) caused by Botrytis cinerea and Penicillium expansum and also delay ripening on tomato fruit. Both disease control and delayed ripening were at similar levels for LIUV and HIPPL treatments on mature green fruit. The HIPPL treatments used in these studies can reduce treatment times for tomato fruit by 97.3%. Both HIPPL and LIUV treatments elicit local responses irrespective of the treatment orientation and tomato fruit, therefore, require full surface irradiation. Furthermore, UV-C in the HIPPL source is not required for disease control or delayed ripening. It does, however, contribute approximately 50% towards the total observed effects. Investigations into the mechanisms underpinning postharvest HIPPL and LIUV hormesis, on tomato fruit, identified that the expression of genes involved in plant hormone biosynthesis, defence, secondary metabolism and ripening were affected. This indicates that disease control is achieved through induced resistance. Changes to expression, following treatment, were highly similar for both HIPPL and LIUV treatments and were mediated by salicylic acid, jasmonic acid and ethylene. This may lead to broad range resistance against necrotrophic and biotrophic pathogens as well as abiotic stresses and herbivorous pests. Recently, the exposure of foliage to UV-C has been shown to induce resistance against B. cinerea on Arabidopsis thaliana. The horticultural applications of such treatments, however, have not been explored. Pre-harvest treatments of lettuce in the glasshouse showed variation in damage threshold and optimal treatment to control disease following LIUV and HIPPL treatment. Further sources of variation included the cultivar, pathogen of interest and the point that treatment was applied during the year. Using a controlled environment allowed seasonal variation to be mitigated and both HIPPL and LIUV treatments controlled disease against B. cinerea. For pre-harvest treatments to be a success in the glasshouse, further studies into how both biotic and abiotic factors influence treatment is required. To circumvent the problems associated with pre-harvest treatments and environmental variation in the glasshouse, LIUV seed treatments were performed on tomato. Control of B. cinerea was established with an approximately 10% reduction in incidence and disease progression with a 4 kJ/m2 treatment. When monitoring the effect of treatment on germination and early seedling development it was also identified that an 8 kJ/m2 treatment led to biostimulation of germination and root and shoot growth.

Submitted by M?rden L?les (marden.inacio@ufvjm.edu.br) on 2016-07-07T23:36:35Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) juliana_augusta_dias.pdf: 999555 bytes, checksum: e69ac3aca1ee6f2ffd2746e03912a88f (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2016-07-11T19:32:39Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) juliana_augusta_dias.pdf: 999555 bytes, checksum: e69ac3aca1ee6f2ffd2746e03912a88f (MD5) / Made available in DSpace on 2016-07-11T19:32:39Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) juliana_augusta_dias.pdf: 999555 bytes, checksum: e69ac3aca1ee6f2ffd2746e03912a88f (MD5) Previous issue date: 2016 / RESUMO Introdu??o: embora as complica??es no parto e puerp?rio n?o sejam previs?veis e nem previn?veis, os indicadores de mortalidade materna s?o extremamente sens?veis a cuidados obst?tricos de qualidade, e o tempo na obten??o de cuidado adequado ? o fator mais importante relacionado ?s mortes maternas. Objetivo: identificar e analisar a mortalidade materna na regi?o do Alto Jequitinhonha, MG. Metodologia: trata-se de estudo quantitativo, descritivo, com an?lise de dados no SIM/DATASUS, nos atestados de ?bitos e nos prontu?rios das pacientes que evolu?ram para ?bito materno, no per?odo de 2010 a 2013, sobre as caracter?sticas relacionadas aos dados epidemiol?gicos, obst?tricos, situa??o do munic?pio quanto ? exist?ncia de protocolo e investiga??o do ?bito, causas de morte e atraso na assist?ncia. Resultados: a faixa et?ria predominante foi entre 18 e 30 anos, atingindo 50%. Entre as caracter?sticas obst?tricas do ?bito, destaca-se a primiparidade, o terceiro trimestre gestacional, a classifica??o de baixo risco e a incid?ncia de ces?reas. Nos munic?pios, 83,33% n?o apresentam protocolo de atendimento e em 66,66% dos casos n?o foi realizada a investiga??o do ?bito. As principais causas de mortalidade materna encontradas foram diretas, com destaque para a S?ndrome de Hellp, com 25%. Dentre os fatores relacionados ? qualidade do cuidado assistencial, destaca-se o atraso no in?cio do tratamento com 83,33%, assim como o atraso no diagn?stico e o manejo inadequado do paciente, ambos com 75%. Conclus?o: a frequ?ncia de demora na assist?ncia obst?trica est? diretamente relacionada ao pior desfecho materno. / Disserta??o (Mestrado) ? Programa de P?s-gradua??o em Ensino em Sa?de, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2015. / ABSTRACT Introduction: Although complications in childbirth and postpartum are not predictable nor preventable, maternal mortality indicators are extremely sensitive to quality obstetric care and time in getting proper care is the most important factor related to maternal deaths. Objective: To identify and analyze maternal mortality in the region of Alto Jequitinhonha - MG. Methodology: it is a quantitative, descriptive study, with data analysis on the SIM/DATASUS in death certificates and medical records of patients who progressed to maternal deaths in the period 2010 to 2013, on the characteristics related to epidemiological data, obstetric, municipal situation as the existence of protocol and investigation of death, cause of death and delay in assistance. Results: the predominant age group was between 18 to 30 reaching 50.00%. Among the obstetric characteristics of death, there is prim parity the third gestational trimester, the low risk rating and the incidence of cesarean sections. In the municipalities, 83.33% have no treatment protocol and 66.66% of the cases was not carried out the investigation of the death. The main causes of maternal mortality were found direct, highlighting the Hellp syndrome with 25.00%. Among the factors related to quality of care assistance, the delay stands out at the beginning of treatment with 83.33%, and the delay in diagnosis and inappropriate management of the patient, both with 75.00%. Conclusion: The frequency of delays in obstetric care is directly related to the worst maternal outcome. / RESUMEN Introducci?n: A pesar de las complicaciones en el parto y despu?s del parto no son predecibles ni prevenible, los indicadores de mortalidad materna son extremadamente sensibles a la atenci?n obst?trica de calidad y tiempo en conseguir la atenci?n adecuada es el factor m?s importante relacionado con las muertes maternas. Objetivo: Identificar y analizar la mortalidad materna en la regi?n del Alto Jequitinhonha - MG. Metodolog?a: se trata de un estudio cuantitativo, descriptivo, con an?lisis de datos en la tarjeta SIM/DATASUS en los certificados de defunci?n y los registros m?dicos de los pacientes que progresaron a las muertes maternas en el per?odo 2010 a 2013, en las caracter?sticas relacionadas con los datos epidemiol?gicos, situaci?n obst?trica, municipal como la existencia de protocolos y la investigaci?n de la muerte, causa de la muerte y el retraso en la asistencia. Resultados: el grupo de edad predominante fue de entre 18 a 30 a?os alcanza 50.00%. Entre las caracter?sticas obst?tricas de la muerte, hay primiparidad el tercer trimestre de gestaci?n, la calificaci?n de bajo riesgo y la incidencia de ces?reas. En los municipios, el 83,33% no tiene protocolo de tratamiento y 66,66% de los casos no se llev? a cabo la investigaci?n de la muerte. Las principales causas de mortalidad materna se encontraron directa, destacando el s?ndrome HELLP con 25,00%. Entre los factores relacionados con la calidad de la asistencia para el cuidado, la demora se destaca al comienzo del tratamiento con 83,33%, y el retraso en el diagn?stico y el manejo inadecuado de la paciente, ambos con 75,00%. Conclusi?n: La frecuencia de los retrasos en la atenci?n obst?trica est? directamente relacionada con el peor resultado materno.

The cement being used in the construction industry is the result of a chemical process<p>linked to the decarbonation of limestone conducted at high temperature and results in a<p>significant release of CO2. This thesis is part of the project EcoBéton (Green concrete) funded<p>by the French National Research Agency (ANR), with a purpose to show the feasibility of<p>high substitution of cement by mineral additions such as blast furnaces slag, fly ash and<p>limestone fillers. Generally for high percentages of replacements, the early age strength is<p>lower than Portland cement concrete. To cope with this problem, an optimisation method for<p>mix design of concrete using Bolomey’s law has been proposed. Following the encouraging<p>results obtained from mortar, a series of tests on concretes with different substitution<p>percentages were carried out to validate the optimisation method. To meet the requirements of<p>the construction industry related to performance of concrete at early age, which determine<p>their durability, a complete experimental study was carried out. Standard tests for the<p>characterization of the mechanical properties (compressive strength, tensile strength, and<p>setting) allowed to validate the choice of mix design on the basis of equivalent performance.<p>We focused on the hydration process to understand the evolution of the mechanical<p>properties. Setting time measurement by ultrasound device at different temperatures (10°C,<p>20°C and 30°C) showed that ground granulated blast furnace slag (GGBFS) and fly ash<p>delayed the setting process, while use of limestone filler may accelerate this process.<p>Calorimetric studies over mortars and concretes made possible to calculate the activation<p>energy of the different mixtures and a decrease in heat of hydration of concretes with mineral<p>additions was observed which is beneficial for use in mega projects of concrete. Scanning<p>Electron Microscopy observations and thermal analysis have given enough information about<p>the hydration process. It was observed that the hydration products are similar for different<p>concrete mixtures, but the time of their appearance and quantity in the cement matrix varies<p>for each concrete mix.<p>Last part of the thesis was dedicated to the study of main types of shrinkage. First of all,<p>deformations measured were correlated to hydration, capillary depression and porosity<p>evolution. Results allowed concluding that the use of mineral additions has an actual effect on<p>the plastic shrinkage behaviour, but its impact is not proportional to the percentage of<p>additions. Substitution of cement by the additions seems to have a marked influence on the<p>kinetics of the shrinkage without any effect on its long term amplitude. The study of<p>restrained shrinkage under drying conditions by means of ring tests showed that concretes<p>with high percentage of slag addition seem more prone to cracking than the Portland cement<p>concretes. / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished

-Les dynamiques du taux de change en présence de frictions sur les marchés financiers.Cette analyse est une extension du modéle du surajustement « Overshooting » de Dornbusch. Il s'éloigne du modéle de base en faisant l'hypothèse que les marchés financiers ne s'ajustent pas instantanément, « generalised interest parity condition ». Le modele de taux de change sous cette hypothèse, reproduit le surajustement retarde du taux de change nominal. Notre modele arrive aussi a capturer la variation en forme de bosse du taux de change reel et suite a un choc monetaire.-Électorale Cycle de taux de change en CoréeCe papier analyse empiriquement les variations du taux de change reel en Coree du Sud, a l'approche des elections et un peu apres de celles-ci. Nous remarquons que le taux de change baisse juste avant les election mais nous n'avons pu deceler de tendance nette apres. Ce resultat est a l'oppose de celui trouve lors de l'étude des cycles électorales en Amérique latine. Nous expliquons cette divergence par des différences dans la structure économique entre la Corée du Sud et les pays d'Amerique latine-Le régime de change, l'ouverture des marchés de la capitale et de la politique monétaire; Le trilemme en CoréeCet article teste la proposition trilemme en effectuant une étude empirique de Corée. La Corée possède périodes distinctes de toutes les combinaisons de régime de taux de change et l'ouverture du marché des capitaux dans le trilemme: rattaché au régime de taux de change sous le contrôle des capitaux, rattaché au régime de taux de change sous libre circulation des capitaux et des taux de change flottant régime en vertu libre circulation des capitaux. Nous vérifions si l'autonomie monétaire existe dans chacune des trois combinaisons différentes. Nous constatons que l'autonomie monétaire existé au cours des périodes où les contrôles de capitaux et les périodes de régime de taux de change flottant. Pour les périodes avec le régime de parité fixe et libre circulation des capitaux, l'autonomie monétaire a été limitée. En outre, nous identifions que, juste avant la crise financière, le gouvernement a poursuivi la politique monétaire autonome sous le régime de taux de change arrimé et libre circulation des capitaux, défiant ainsi le trilemme. / -Exchange Rate Dynamics under Financial Market FrictionsThis paper extends Dornbusch's overshooting model by proposing “generalized interest parity condition”, which assumes sluggish adjustment on the asset market. The exchange rate model under the generalized interest parity condition is able to reproduce the delayed overshooting of nominal exchange rates and the hump-shaped response to monetary shocks of both nominal and real exchange rates.-Electoral Cycle of Exchange Rate in KoreaThis paper empirically investigates the real exchange rate behavior around elections in Korea. We find that the real exchange rate depreciates more before the elections but there is no clear pattern found after the elections. Interestingly, this result is the opposite of the electoral cycle found in Latin American countries. To explain this results we should consider the difference between economic backgrounds of Korea and Latin American countries.-Exchange Rate Regime, Capital Market Openness and Monetary Policy; The Trilemma in KoreaThis paper tests the trilemma proposition by performing an empirical study of Korea. Korea has distinct periods of all combinations of exchange rate regime and capital market openness in trilemma: pegged exchange rate regime under capital controls, pegged exchange rate regime under free capital mobility, and floating exchange rate regime under free capital mobility. We check whether monetary autonomy exists in each of the three different combinations. We find that monetary autonomy existed over the periods with capital controls and the periods with floating exchange rate regime. For the periods with the pegged exchange rate regime and free capital mobility, monetary autonomy was limited. In addition, we identify that just before the financial crisis the government pursued autonomic monetary policy under pegged exchange rate regime and free capital mobility, thereby defying the trilemma.

The thesis aimed at finding out whether parents of toddlers with delayed psychomotor development undergoing curative spa stays administer food supplements, their reasons for administering them and what kinds and how often food supplements are administered. Eating habits of these children were looked into as well. Children with polio and central infantile hypotonic syndrome took part in the research. Quantitative research method using an anonymous questionnaire was employed for data collection. Altogether, there were 50 respondents. The results showed that 72 % (n=36) of parents already administered their children food supplements at such an early age. The most frequent motive for this was to strengthen the immune system. Vitamin supplements counted among the most frequently administered supplements in the sample. Furthermore, the research showed that not even the food composition of children in the sample was ideal. The results proved that it is highly desirable to pursue nutrition education of parents of children with neurological handicaps and chiefly also assure higher awareness of food supplements. Key words: dietary supplements, nutrition, toddler period, delayed psychomotor development, vitamins, cerebral palsy

Made available in DSpace on 2015-07-22T20:50:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-09-29 / Objetivo: investigar a participação da imunidade inata, através da análise de expressão dos genes TLR4 e MYD88, na disfunção precoce do enxerto renal em humanos. Métodos: A quantificação do mRNA foi realizada por PCR em tempo real, em biópsias pré-implantação do enxerto, na urina e no sangue (leucócitos) do primeiro dia póstransplante, em 75 transplantes (TX) com doador falecido (DF) e 18 transplantes com doador vivo (DV). Os desfechos considerados foram DGF (delayed graft function) e retardo na recuperação da função renal, independentemente de necessidade de diálise. Resultados: Em biópsias, os níveis de expressão de TLR4 e MyD88 foram maiores em rins de DF do que de DV; mas não se correlacionaram com disfunção precoce do enxerto; na urina, não diferiram entre DF e DV, e tenderam a ser mais elevados em casos de TX-DF com disfunção precoce do enxerto; no sangue, não diferiram entre DF e DV e foram mais baixos em casos com disfunção precoce. Conclusão: os resultados sugerem uma participação de TLR4 e MYD88 na patogenia das alterações que ocorrem em rins de DF e que baixos níveis de expressão gênica de TLR4 e MYD88, mensurados em amostra de leucócitos do sangue periférico colhida nas primeiras 24 horas pós-transplante, podem predizer retardo na recuperação da função do enxerto e, portanto, poderão vir a ter utilidade clínica no tratamento de receptores de transplante renal de doador falecido. / TEDE / BV UNIFESP: Teses e dissertações

Dans le cadre du stockage des déchets radioactifs en couches géologiques profondes (argilite du Callovo-Oxfordien), des bétons à faible alcalinité et à faible chaleur d'hydratation référencés "bas pH " ont été élaborés. L'utilisation de ces types de béton permet de limiter la dégradation des propriétés confinantes du matériau argileux type bentonite. Deux bétons bas pH à base de liants ternaires ont étudiés : un composé de ciment, fumée de silice et cendres volantes (TCV) et l'autre composé de ciment, fumée de silice et laitier moulu de haut fourneau (TL). L'objectif de l'étude est d'analyser le comportement de ces matériaux pour s'assurer : d'une mise en œuvre correcte à l'échelle industrielle, d'une bonne tenue chimique et mécanique dans le temps et d'un confinement performant. Le programme expérimental comprend la caractérisation physico-chimique et mécanique de ces matériaux à forte teneur en additions et est couplé à de la modélisation dans le but, in fine, de disposer d'outils permettant de prédire leur comportement au sein de l'ouvrage. Les résultats montrent qu'un cobroyage des constituants du liant permet d'améliorer la réactivité du liant et de s'assurer d'une bonne robustesse des formules de béton. La condition essentielle de l'obtention d'un pH de leur solution interstitielle de 11 est assurée dès 28 jours. Les bétons peuvent être considérés à faible chaleur d'hydratation du fait des échauffements rencontrés à court terme. A long terme, de hautes performances mécaniques, de faibles coefficients de perméabilité et de diffusion sont obtenus sur ces matériaux. Les modélisations de l'hydratation, de l'évolution de propriétés mécaniques, de l'endommagement, des déformations différées et des transferts hydriques ont été abordées. Le modèle d'hydratation utilisé a été adapté aux liants ternaires en prenant en compte les phénomènes de nucléation des additions sur l'hydratation du ciment. Pour les autres modèles, l'acquisition des mesures expérimentales a permis de fournir les données d'entrée pour leur utilisation et de vérifier leur validité sur des liants fortement dilués. Tous ces travaux permettent au final d'envisager sereinement la modélisation et la prédiction du comportement des structures réalisées en béton bas pH. / In the context of the radioactive wastes disposal in deep geological repository of clay, low-alkalinity and low heat of hydration concretes referenced "low pH " were designed. The degradation of the properties of the clay can be limited by using these types of concrete. Two types of low pH binder were chosen for this research: the first one is comprised of cement, silica fume and fly ash (TCV) and the other one is comprised of cement, silica fume and slag (TL). The objective of this research is to comprehend the behavior of these concrete in order to ensure the well-placing of the fresh concrete at an industrial scale and good mechanical performances, chemical stability and confining properties. The experimental program focuses on a physico-chemical and mechanical characterization of these recent materials with high pozzolanic addition content. The experimental data are then modeled for the purpose of having a tool that, in the end, is able to predict the behavior of the low pH concretes within the structure. The results show that grinding altogether the three constituents improves the reactivity of the binder and allows a good reproducibility of the low pH design. The most important criterion which is a pH of the interstitial solution below 11 is met at 28 days. The heat measurements at early age show that the low pH concretes are low heat of hydration concretes as well. In the long run, high mechanical performances, low permeabilities and diffusivities were obtained on these materials. The modeling of the hydration, evolution of mechanical properties, damage, creep and hydric transfers is also covered in this thesis. The model of hydration was adjusted to match the hydration of ternary binders by taking into account the effects of the additions such as the heterogeneous nucleation, on the hydration of the cement. As for the other models, the experimental results were used as data input to validate the models on binders with high replacement rates. Ultimately, this work allows us to contemplate serenely the modeling and the prediction of the behavior of structure made of low pH concretes.