• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • 1
  • Tagged with
  • 5
  • 5
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The effect of intermittent cathodic protection on corrosion protection in the intertidal zone

Shi, Wei January 2016 (has links)
As an important technique for corrosion control in marine environment, Cathodic Protection (CP) should be applied with a full understanding of environmental conditions and a good consideration of current requirements. Early studies on different kinds of steel specimens in the intertidal zone show severe corrosion losses. Nevertheless, there is evidence that CP can work in these regions of a steel structure because electrolyte pathway can remain some time on thin wetted surfaces when tides recede. This research aims to study corrosion activities and their behaviour under the influence of CP in a thin layer of electrolyte as a simulation of the inter-tidal zone. By means of a mechanical vibrating probe, Scanning Vibrating Electrode Technique (SVET) may be used to study local activities at coating defects in a thin electrolyte layer. The effect of CP on the local currents at the defect site was confirmed by SVET and, significantly, the development of calcareous films under these conditions in seawater was also observed. Such films are found to be effective in the absence of cathodic polarisation and only failed after damage. In order to explore the performance of applying CP, a Finite Element (FE) model of electrically connected zinc and steel samples beneath a specific thickness of electrolyte has been created, with full polarisation curves implemented for each metal based on experimental results obtained. The influence of the electrolyte conductivity and the geometry of the electrodes has also been considered. A comparison can then be made between experimental investigation and computational modelling of this corrosion cell. Epoxy-coated and uncoated mild steel samples obtained in the simulated tidal facility were also investigated. The formation of calcareous films was confirmed. Calcareous films were protective under these intermittent wetting conditions. Techniques used to understand the performance include optical observation, Scanning Electron Microscopy (SEM) together with Energy Dispersive X-ray (EDX) and X-ray Diffraction (XRD) analysis.
2

Méthode stochastique de délimitation des zones de protection autour des captages deau - Conditionnement par des mesures de conductivité hydraulique K, de hauteur piézométrique h et de résistivité électrique ρ

Rentier, Céline 14 March 2003 (has links)
Dans les milieux géologiques hétérogènes, la délimitation des zones de protection autour de puits de captage repose sur la fiabilité des modèles hydrogéologiques utilisés. Celle-ci dépend essentiellement de notre capacité à décrire les propriétés du système aquifère. En raison des mécanismes géologiques complexes impliqués dans la formation des dépôts sédimentaires, les propriétés aquifères et en particulier la conductivité hydraulique (K) montrent une variabilité spatiale importante, qui gouverne l'étalement de soluté. Le manque de données empêche une caractérisation parfaite du champ de K et introduit dès lors une incertitude dans la délimitation des zones de protection. Divers types d'informations liées à cette propriété peuvent être récoltés sur le terrain mais sont, en pratique, peu utilisés en raison de la difficulté de les intégrer dans les modèles hydrogéologiques. Dans ce travail de recherche, l'accent a été mis sur la quantification et la réduction de l'incertitude associée à la localisation des zones de protection en proposant une méthode stochastique permettant de conditionner les champs de K par des mesures directes (données hard) et indirectes (données soft) de cette propriété et plus particulièrement des données de résistivité électrique (ρ) et de hauteur piézométrique (h). L'approche stochastique spatiale qui a été adoptée considère la propriété K comme une fonction spatiale aléatoire et permet, par l'utilisation de méthodes géostatistiques, de caractériser sa variabilité spatiale. Cette approche stochastique génère un ensemble de champs de K, tous statistiquement équiprobables et, par analyse de Monte Carlo, prend explicitement en compte l'incertitude sur les valeurs de K dans la réponse du système, contrairement aux approches déterministes classiques qui considèrent le champ de K calibré comme la meilleure représentation de la réalité et mènent à la définition d'une zone de protection unique dont l'incertitude n'est pas quantifiable. Afin d'évaluer la qualité des résultats obtenus, cette méthode a été appliquée à un cas d'étude virtuel (synthétique) représentant une situation de référence, aussi proche que possible des conditions réelles rencontrées dans les aquifères alluviaux, et dont les propriétés hydrogéologiques sont connues en tout point du domaine modélisé. Elle a également été appliquée au cas d'étude réel d'un aquifère alluvial ayant déjà fait l'objet d'une étude déterministe et dont le nombre de mesures de K est extrêmement faible, nécessitant l'intégration de données de ρ et de h. L'ensemble des résultats montre à quel point l'introduction des données soft, et surtout celle des données de ρ, est un atout qui améliore grandement la caractérisation des champs de K et permet donc non seulement de réduire l'incertitude sur la localisation des zones de protection, mais également d'approcher la forme du tracé des zones de protection réelles. ABSTRACT In heterogeneous geological media, delineation of time-related well capture zone is based on the reliability of the hydrogeological models. It depends strongly on our ability to describe the system aquifer properties. Due to the complex geological processes leading to the formation of natural sediments, aquifer properties and in particular hydraulic conductivity (K) exhibits a large degree of heterogeneity, which governs solute spreading. The lack of K data hampers the complete determination of the K field and introduces uncertainty in capture zone delineation. Several kinds of informations related to this parameter can be collected in the field but are most often not used in practice because of the difficulty to introduce them in hydrogeological models. In this research work, emphasis is given to quantification and reduction of the well capture zone uncertainty by developing a stochastic method integrating direct (hard data) and indirect (soft data) measures of K and particularly electrical resistivity (ρ) and piezometric heads (h). The spatial stochastic approach adopted here considers the property K as a spatial random function and describes its spatial variability by use of geostatistical methods. This approach generates a range of statistically equally likely K fields and takes explicitly into account the K values uncertainty in the system response by performing Monte Carlo analysis, unlike classical deterministic approaches that consider a calibrated K field as the best representation of reality and lead to the definition of a unique capture zone for which uncertainty is unquantified. In order to assess the reliability of the results, this method was applied to a virtual (synthetic) study representing a reference case, very similar to actual alluvial aquifer conditions and for which hydrogeological properties are perfectly known. The method was also applied to a real case of an alluvial aquifer that had already been studied in a determinist framework and for which the number of K measures is very scarce, requiring a conditioning by ρ and h data. The results show how introduction of soft data and especially ρ data greatly improves K field description and therefore allows both to reduce well capture zone uncertainty and to approach the shapes of actual protection zones.
3

Statistické šetření vybraných úkolů ochrany obyvatelstva v zónách havarijního plánování jaderných elektráren / The statistical investigation of selected tasks in protection of the population in emergency planning zones of nuclear power plants

HAJÍČKOVÁ, Iva January 2015 (has links)
The thesis deals with statistical investigation of selected tasks in population protection in emergency planning zones of nuclear power plants.The issues of population protection have been developing since 1930s up to now.Currently,the population protection is addressed particularly in concepts of population protection,while the most recent one is the Population Protection Concept until 2020 with an Outlook to 2030.The objective of the thesis was to compare awareness of the population in emergency planning zones of nuclear power plants.With regard to a potential extraordinary event,in this case a radiation accident,the awareness of the population plays a significant role.The theoretical part of the thesis analyzes population protection,legal regulations and documents dealing with this topic.It also defines measures in population protection which seek to mitigate impact of extraordinary events or emergency situations on health and lives of the population,property and the environment.The thesis also mentions emergency planning and describes types of emergency plans.The second section of the theoretical part describes selected statistical methods.The last chapter of the theoretical part describes methods of multidimensional statistics.The following hypotheses and partial hypotheses were formulated in the research part of the thesis to meet its objective: H1 There is no statistically significant difference between the emergency planning zone of the nuclear power plant Temelín and the emergency planning zone of the nuclear power plant Dukovany.H11 There is no statistically significant difference in awareness among men about a potential extraordinary event at NPP Temelín and NPP Dukovany.H12 There is no statistically significant difference in awareness among women about a potential extraordinary event at NPP Temelín and NPP Dukovany. H2 The awareness of the population in emergency planning zones of both the nuclear power plants has a theoretical distribution which is close to the normal distribution.H21 The awareness of the population (men) in the emergency planning zone of NPP Temelín has a theoretical distribution which is close to the normal distribution.H22 The awareness of the population (women) in the emergency planning zone of NPP Temelín has a theoretical distribution which is close to the normal distribution.H23 The awareness of the population (men) in the emergency planning zone of NPP Dukovany has a theoretical distribution which is close to the normal distribution.H24 The awareness of the population (women) in the emergency planning zone of NPP Dukovany has a theoretical distribution which is close to the normal distribution.All the formulated hypotheses were tested with methods of descriptive and mathematical statistics. The research was conducted with questionnaires handed out in the emergency planning zones of NPP Temelín and NPP Dukovany.The questionnaire consisted of 23 questions and it was filled out by 242 men and 270 women in the zones.All data used in the research were provided to me within the project "Population protection depending of differentiation of the population" safety survey (VG20132015122) performed at the department of radiology,toxicology and population protection at the Faculty of Health and Social Studies at the University of South Bohemia in České Budějovice in cooperation with the Fire Rescue Service of the Czech Republic.Results of the research have shown that the average awareness of the population living in the emergency planning zones of the nuclear power plants is less than 50% and that the knowledge of the population about a potential extraordinary event is not satisfactory.The population living in emergency planning zones of both the nuclear power plants could be exceptionally prepared for a potential non-standard situation, not only in the form of a Gauss curve.
4

Zásady připravenosti rodiny na evakuaci ze ZHP JE / The principles of family readiness for evacuation from EPZ of nuclear power plant

MENČÍKOVÁ, Lucie January 2019 (has links)
This thesis examines the level of knowledge of families living in the emergency plan-ning zone of Nuclear power plant Temelín. It focuses mainly on the knowledge of eva-cuation baggage contents, evacuation routes, organs that organize this measure and other important information, which are found in particular in the Manual for the pro-tection of population in the radiation accident of the Nuclear power plant Temelín. The theoretical part is based on the analysis of current problematics. The first part is focused on the principle of the operation of the nuclear power plant and its security, which is emphasized. Further it deals with the topic of radiological emergency and consequently the effect of ionizing radiation on the organism. The next chapter is devoted to the issue of issue of protective measures that could be announced during the radiation accident of the nuclear power plant. In the last section of the theoretical part, the work focuses on the topic of emergency plans, as these are necessary to establish rules that would require the authorities and residents to follow if necessary. In connection with these topics, the legal framework dealing with the issue is mentioned. The practical part verifies the level of awareness of families living in the emergency planning zone of a nuclear power plant on how to proceed with the evacuation. For this purpose, a quantitative questionnaire survey was used and a hypothesis was established claiming that at least 50% of the respondents did not have sufficient knowledge of how to proceed during the evacuation from EPZ of nuclear power plant. The methodology for statistical processing was set out. After evaluating the obtained data, the answers to individual questions were compiled graphically. Furthermore, the thesis deals in detail with individual questions. The established hypothesis is confirmed by evaluating the results using descriptive statistics methods. In the discussion, the questions that have been identified and the findings are discussed. Furthermore, there are suggested ways to improve population awareness of the issue,
5

La protection juridique du patrimoine culturel en Chine

Zhao, Zhiyong 25 October 2013 (has links)
Le patrimoine culturel chinois se compose d’une multitude de biens matériels et immatériels. Il incarne la vitalité et la créativité de la nation chinoise. Il participe aussi au devenir de la civilisation chinoise. La question du patrimoine culturel constitue une préoccupation majeure dans la société chinoise contemporaine. Selon l’évolution politique du pays, des mesures juridiques ont été adoptées. Enjeu actuel pour le Gouvernement et les autorités locales, des règlementations spécifiques ont été mises en place pour assurer la protection du patrimoine culturel. Elles ne cessent d’être complétées et améliorées dans un contexte de patrimonialisation mondialisée dans le cadre de la Convention concernant la protection du patrimoine mondial, culturel et naturel de 1972 et de la Convention pour la sauvegarde du patrimoine culturel immatériel. L’application de la loi sur la protection du bien culturel et de la loi pour la sauvegarde du patrimoine culturel immatériel et l’intervention du juge permettent d’apprécier leur portée effective / Chinese cultural heritage consists of a multitude of tangible and intangible assets. It embodies the vitality and creativity of the Chinese Nation, and also participates in the pursuit of Chinese civilization Cultural heritage is the main problem of contemporary Chinese society. According to political developments, legal measures have been adopted. Because of current challenges for the Government and local authorities, specific regulations have been put in place to ensure the protection of cultural heritage. They are constantly being added to and improved in with the Global Heritage phenomenon, under the Convention Concerning the Protection of World Cultural and Natural Heritage and the Convention for the safeguarding of Intangible Cultural Heritage. The application of the law for the protection of Cultural Relics and the law for the safeguarding of Intangible Cultural Heritage and the intervention of jug allow appreciating its effective range

Page generated in 0.1286 seconds