L'anevrysme intracrânien (AIC) est une anomalie morphologique spécifique des artères cérébrales exposant au risque, particulièrement grave, de saignement intracrânien. Malgré les progrès établis dans le traitement curatif , aucun traitement préventif de la formation des AIC n’a été prouvé chez l’Homme. L’absence de traitement non invasif et l’absence de consensus sur le traitement des AIC non rompus sont le corolaire direct d’un manque de connaissance des mécanismes physiopathologiques de la maladie anévrysmale.L’ensemble du travail exposé ici a eu pour but de mieux comprendre les mécanismes de la pathologie anévrysmale intracrânienne pouvant être la base de nouvelles stratégies préventive améliorant le traitement des AIC.Nous avons tout d'abord étudié l'influence des anomalies du tissus de soutien des artères cervicales sur la formation des AIC. Au cours de cette étude, nous avons réalisé une étude cas-témoins dont l’objectif principal était d’étudier l’association entre les anomalies morphologiques des artères cervicales et la présence d’un AIC. Les objectifs secondaires étaient premièrement d’examiner si cette association variait selon le caractère rompu ou non de l’anévrisme et deuxièmement d’examiner si la sévérité des anomalies artérielles cervicales était liée à la sévérité de la pathologie anévrismale. Nous rapportons que la prévalence des anomalies angiographiques chez les patients porteurs d’AIC est élevée. De plus l’incidence d’une pathologie rare, la dysplasie fibro-musculaire est très élevée chez les patients porteurs d’AIC comparativement à la population générale. La présence des anomalies angiographiques n’a aucun impact sur l’évolution naturelle des AIC vers la rupture, ni sur d’autres aspect comme leur taille, leurs nombres ou leur forme. Dans le cadre de notre étude, nous pensons que l’association entre les anomalies angiographiques et les AIC semble être expliquée par l’hypothèse d'une vulnérabilité du tissu de soutien pariétal (condition pathologique particulière de la paroi artérielle à l’origine de la formation des AIC). Cette condition pathologique, affecterait de manière diffuse la vascularisation cérébrale et les artères cervicales. Les AIC seraient ainsi des manifestations cliniquement « bruyantes » de pathologies vasculaires plus silencieuses affectant la paroi de l’ensemble des vaisseaux. Les anomalies morphologiques des artères cervicales témoignent de façon sensible mais très peu spécifique de l’association des pathologies du tissu de soutien avec la présence d’AIC.Dans une deuxième partie nous essayons de décrire et de caractériser une voie inédite de la formation et de la croissance des AIC, la voie de la fibrinolyse via l'activateur de plasminogène de type tissulaire (tPA). Nos données suggèrent que le tPA présent dans la circulation sanguine est suffisant pour favoriser la formation et la rupture des anévrismes. Nous avons donc proposé que le tPA vasculaire était un des responsables de la formation des AIC. Nous avons également constaté une certaine continuité dans le temps de l'influence du tPA sur le remodelage matriciel. Nous avons donc proposé le tPA vasculaire comme une nouvelle cible possible pour prévenir la progression et la rupture des AIC. Différentes expériences ont été entreprise pour inhiber sélectivement le tPA et les résultats préliminaires sont encourageants et ouvrent la voie à une stratégie thérapeutique non invasive inédite. On peut aussi imaginer que ces différentes approches puissent être combinées entre elles et avec des agents matriciels ciblant directement l’activité du tPA dans la paroi des AIC. L’amélioration des stratégies thérapeutiques dans la pathologie anévrysmale intracrânienne est définitivement un axe de recherche dont les possibilités sont immenses et les résultats nécessaires et attendus. / Intracranial aneurysm (IA) is a specific morphological abnormality of the cerebral arteries that exposes to devastating intracranial bleeding. Despite the progress made in the curative treatment, no preventive treatment of IA formation has been proven in humans. The lack of non-invasive treatment and consensus on the treatment of unruptured IA are the consequences of the lack of knowledge of the physiopathological mechanisms of aneurysmal disease. All of the work presented here aims to better understand the mechanisms of intracranial aneurysmal pathology, which may be the basis of new preventive strategies improving the treatment of IA.We first studied the influence of cervical artery abnormalities on IA formation. In this study, we performed a case-control study whose main objective was to study the association between morphologic abnormalities of cervical arteries and the presence of IA. The secondary objectives were first to examine whether this association varied according to whether or not the aneurysm was broken, and secondly to examine whether the severity of the cervical arterial abnormalities was related to the severity of the aneurysmal pathology. We report that the prevalence of angiographic abnormalities in patients harboring IA is high. In addition, the incidence of a rare pathology, fibro-muscular dysplasia is very high in patients with IA compared to the general population. The presence of angiographic abnormalities has no impact on the rupture of the IA, nor on other aspects such as their size, numbers or shape. In our study, we believe that the association between angiographic abnormalities and IA seems to be explained by the hypothesis of a vulnerability of the arterial wall (a particular pathological condition of the arterial wall at the origin of IA formation). This pathological condition would affect the whole cerebral vasculature and cervical arteries. IA would thus be the clinical manifestations of more silent vascular pathologies affecting the wall of all vessels. The morphological abnormalities of the cervical arteries testify sensitively but not very specifically of the association of the arterial wall diseases with the presence of IA.In a second study, we try to describe and characterize an unprecedented pathway of formation and growth of IA : the pathway of fibrinolysis via tissue-type plasminogen activator (tPA). Our data suggest that tPA present in the bloodstream is sufficient to promote formation and rupture of aneurysms. We therefore proposed that vascular tPA was one of those responsible for training IA. We also noted a certain continuity in the time of the influence of the tPA on the matrix remodeling. We therefore proposed vascular tPA as a possible new target to prevent progression and rupture of IA. Various experiments have been undertaken to selectively inhibit tPA and the preliminary results are encouraging and open the way to an unprecedented non-invasive therapeutic strategy. It is also conceivable that these different approaches could be combined with each other and with matrix agents directly targeting tPA activity in the AIC wall. The improvement of therapeutic strategies in intracranial aneurysmal pathology is definitely an topic of ​​research whose possibilities are huge and the results necessary and expected.

Dans le domaine de la modélisation du trafic routier, des améliorations sont nécessaires afin de permettre de simuler des situations accidentogènes. La grande majorité des modèles microscopiques actuels à base d'agents pour la simulation de trafic concerne l'activité décisionnelle du conducteur. Or, l'activité de perception est un préalable important à la décision. Notre objectif est donc de proposer de nouvelles solutions pour la modélisation agent de la perception du conducteur humain. La proposition comprend une double activité de perception (passive et active), couplée à une limitation quantitative des percepts (limite de la mémorisation à court-terme). Le modèle a été implémenté et testé dans le contexte d'un carrefour pour lequel nous possédons un ensemble de données d'observation. Les résultats obtenus confirment l'intérêt du modèle pour simuler des comportements proches des comportements observés et des variations inter-individuelles dans la population de conducteurs. / In the context of traffic modeling, we need some improvements in order to allow to simulate the near accident situations. The most actual agent based traffic simulations tools focuse on the decision activity of drivers. However, the activity of perception is an important precondition of decision. We aim to propose new solutions for agent based modeling of human drivers perception. The proposition include a double activity of perception (passive and active), coupled with a quantitative limitation of percepts (depending on the limit of short term memory). The model has been implemented and tested in the context of a crossroad for which we have a set of observation data. The obtained results confirm the interest of the model to simulate the behaviors of drivers more realistically, and to improve interindividual variations in the driver population.

Eine Vielzahl von Wissenschaftlern und Wissenschaftlerinnen befassen sich mit der Unfalltheorie und den darauf einflussnehmenden Faktoren, mit dem Ziel die Straßenverkehrssicherheit für alle Verkehrsteilnehmende zu verbessern. So wird auch in der vorliegenden Arbeit der Einfluss der Regionen (Unterschied zwischen Ost- und Westdeutschland) und des Verkehrskontextes (Bundesautobahnen, außerhalb und innerhalb von Ortschaften) auf die Häufigkeit von Straßenverkehrsunfällen, differenziert nach der Unfallschwere, untersucht. Nach einer eigenständigen Recherche der auf die jeweiligen Bundesländer und Straßentypen differenzierten Fahrleistungen, welche für das Jahr 2015 in Deutschland, erbracht worden sind, werden mit Hilfe von Regressionsmodellen Risikokennziffern für die differenzierten Häufigkeiten von Verunglückten (Getöteten, Schwerverletzten, Leichtverletzten) ermittelt. Diese wurden mit der Statistiksoftware R durchgeführt. Abschließend ist zu sagen, dass die Aussagen für Unfälle mit getöteten Personen nicht für Unfälle mit schweroder leichtverletzten Personen gelten und die Bundesautobahn nach den Risikokennziffern der sicherste Straßentyp ist. Schlussendlich werden die erhaltenen Kennziffern diskutiert.:INHALTSVERZEICHNIS I ABBILDUNGSVERZEICHNIS III TABELLENVERZEICHNIS IV FORMELVERZEICHNIS V ABKÜRZUNGSVERZEICHNIS VI ABSTRACT VIII 1 EINLEITUNG 1 2 DESKRIPTIVE ANALYSE DES DATENSATZES 3 2.1 RECHTSGRUNDLAGE 4 2.2 BEGRIFFSERKLÄRUNG 5 2.2.1 Unfälle 5 2.2.2 Beteiligte 6 2.2.3 Verunglückte 7 2.2.4 Unfallursachen 7 2.2.5 Unfallarten und Unfalltypen 8 2.2.5.1 Unfallarten 8 2.2.5.2 Unfalltypen 8 3. LITERATURÜBERBLICK 10 3.1 PALMERA-SUAREZ, LOPEZ-CUADRADO ET AL. 10 3.2 WANG, QUDDUS AND ISON 12 3.3 TAYLOR, LYNAM AND BARUYA14 4. VORGEHENSWEISE 17 4.1 ERMITTLUNG DER DIFFERENZIERTEN FAHRLEISTUNGEN 19 4.1.1 DTV-tägliche Verkehrsstärken 20 4.1.2 Hochrechnung auf das Jahr 2015 21 4.2 VERWENDETE PROGRAMME 24 5. DURCHFÜHRUNG 25 5.1 VORBETRACHTUNG 25 5.1.1 Erstellen der Datenmatrizen 25 5.1.2 Streudiagramm 27 5.1.3 Bestimmtheitsmaß 31 5.1.4 F-Test 31 II 5.2 REGRESSION: GETÖTETE AUF BUNDESAUTOBAHNEN 32 5.3 REGRESSION: GETÖTETE AUßERHALB VON ORTSCHAFTEN 38 5.4 REGRESSION: GETÖTETE INNERHALB VON ORTSCHAFTEN 40 5.5 REGRESSION: SCHWERVERLETZTE AUF BUNDESAUTOBAHNEN 42 5.6 REGRESSION: SCHWERVERLETZTE AUßERHALB VON ORTSCHAFTEN 45 5.7 REGRESSION: SCHWERVERLETZTE INNERHALB VON ORTSCHAFTEN 46 5.8 REGRESSION: LEICHTVERLETZTE AUF BUNDESAUTOBAHNEN 49 5.9 REGRESSION: LEICHTVERLETZTE AUßERHALB VON ORTSCHAFTEN 51 5.10 REGRESSION: LEICHTVERLETZTE INNERHALB VON ORTSCHAFTEN 54 6. ERGEBNISSE 56 7. DISKUSSION 58 7.1 GETÖTETE 59 7.2 SCHWERVERLETZTE 60 7.3 LEICHTVERLETZTE 61 8. SCHLUSSBETRACHTUNG 62 LITERATURVERZEICHNIS 65 ERKLÄRUNG ZUR URHEBERSCHAFT 68

The diploma thesis focuses on the topic of environmental migration because of the Chernobyl nuclear accident in 1986. The main questions of the thesis are whether the Chernobyl accident is associated at any social level with environmental migration to the Czech Republic? To what time is the event socially framed? In what areas and how does the accident currently affect the lives of the environmental migrants? The diploma thesis has two research parts. The first part is a media analysis, which shows that the Chernobyl accident is mostly socially perceived as a matter of the past and is not associated with environmental migration to the Czech Republic. The second research part is based on anthropological research of semi- structured interviews with respondents. The result of this research is the division of radiation toxicity into five dimensions (political, biological, potential, reproductive, migration), in which the consequences of the Chernobyl accident continue to manifest themselves in the lives of environmental migrants. The dimensions of toxicity take place in different time frames, so the work also focuses on the temporality of modern accidents. The social perception of the Chernobyl accident as a finished event does not mean that it is no longer present in human lives. The aim of the...

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Considering the unlikely core melt down scenario for a light water reactor (LWR) a possible failure mode of the reactor pressure vessel (RPV) and its failure time has to be investigated for a determination of the loadings on the containment. Worldwide several experiments have been performed accompanied with material properties evaluation, theoretical, and numerical work. At the Institute of Safety Research of the FZR a finite element model has been de-veloped simulating the thermal processes and the viscoplastic behaviour of the ves-sel wall. An advanced model for creep and material damage has been established and has been validated using experimental data. The thermal and the mechanical calculations are sequentially and recursively coupled. The model is capable of evalu-ating fracture time and fracture position of a vessel with an internally heated melt pool. The model was applied to pre- and post test calculations for the FOREVER test se-ries representing the lower head RPV of a PWR in the geometrical scale of 1:10. These experiments were performed at the Royal Institute of Technology in Stock-holm. The results of the calculations can be summarised as follows: # The creeping process is caused by the simultaneous presence of high tem-perature (>600 °C) and pressure (>1 MPa) # The hot focus region is the most endangered zone exhibiting the highest creep strain rates. # The exact level of temperature and pressure has an influence on the vessel failure time but not on the failure position # The failure time can be predicted with an uncertainty of 20 to 25%. This uncer-tainty is caused by the large scatter and the high temperature sensitivity of the viscoplastic properties of the RPV steel. # Contrary to the hot focus region, the lower centre of the vessel head exhibits a higher strength because of the lower temperatures in this zone. The lower part moves down without significant deformation. Therefore it can be assumed, that the vessel failure can be retarded or prevented by supporting this range. # The development of a gap between melt crust and vessel wall could not be proofed. First calculations for a PWR geometry were performed to work out differences and commonalities between prototypic scenarios and scaled experiments. The results of the FOREVER-experiments cannot be transferred directly to PWR geometry. The geometrical, mechanical and thermal relations cannot be scaled in the same way. Because of the significantly higher temperature level, a partial ablation of the vessel wall has to be to expected in the PWR scenario, which is not the case in the FOREVER tests. But nevertheless the FOREVER tests are the only integral in-vessel retention experiments up to now and they led to a number of important insights about the behaviour of a vessel under the loading of a melt pool and pressure.

Untersuchung von insgesamt 1537 Schulunfällen von Kindern und Jugendlichen im Alter von 6 bis einschließlich 17 Jahren, die in den Jahren 1998 und 1999 an den Kliniken für Unfall- und Wiederherstellungschirurgie und für Kinderchirurgie am Universitätsklinikum Dresden behandelt wurden. Auswertung unter Einbeziehung von Geschlecht, Alter, Schulart, Art der schulischen Veranstaltung, Wegeunfälle, Unfallort, Unfallmechanismus, Unfallumstände, Verletzungslokalisation, Verletzungsart, Diagnose, Behandlungsdauer, Diagnostik, Therapie, Verletzungsfolgen, usw. / Examination of 1537 school accidents of pupils aged between 6 and 17 years who where treated at the university hospital of Dresden in the years 1998 and 1999. Analysis of sex, age, type of school, type of school activity during which injury occured, accident on the way to school, place of accident, mode of accident, backgrounds of accident, localization of injury, type of injury, diagnosis, duration of treatment, clinical diagnostics, therapy, consequences of injury, etc.

Tunnel safety – an inventory of accidents in four road tunnels in Stockholm This report investigates traffic accidents in four road tunnels in Stockholm. The tunnels investigated are Klaratunneln, Söderledstunneln, Törnskogstunneln and Häggvikstunneln. The main purpose of this project was to work with a delimited part of the project TUFS (Tunnel Framkomlighet och Säkerhet, Tunnel practicability and safety, my translation) that is going to build a knowledge bank for Swedish road tunnel accidents. The goal of this project was to investigate if the forecasts for accident rates in the tunnels calculated from empirical data differ from the forecasts of the road network made by the forecast program used by Trafikverket, Lill-EVA, for the observed tunnels. Another goal was to determine where accidents occur in the tunnels. In addition, two different tunnel types were compared in terms of accident rates. The tunnel types are located in: countryside (high speed, low traffic flows, no on- and off ramps) or urban center (low speed, high traffic flows, on- and off ramps). Accident data has been collected from the data bases STRADA and NTS and compiled in histograms displaying accident type, light conditions, the seriousness of the accident and number of accidents/year. The results showed that there are no differences in accident rates calculated by Lill-EVA and empirical data for accident rate, serious accident rate and death rate. However, there was a difference in the results concerning light injuries. No difference was found regarding the two tunnel types. Rear-end collision was the most common accident type in Söderledstunneln and serial vehicle crashes in Törnskogstunneln and Häggvikstunneln. Vehicles that got stuck in the tunnel entrance dominated the accident type in Klaratunneln. The majority of the accidents occurred in daylight. The coordinate positions for the accidents showed that there was a concentration of accidents near the tunnel entrance in Klaratunneln, Söderledstunneln and Häggvikstunneln. This is not the case for Törnskogstunneln where accidents have occurred in the tunnel center.

In accident analysis regarding nuclear power plants, it is very common to use thermal hydraulic system codes, such as TRACE, developed by U.S. NRC. In the case of licensing a power plant, this is one of the necessities. TRACE is a relatively new thermal hydraulic system code and a lot of knowledge is needed to implement it in a correct way, especially in accident analysis, where it is a requirement that the rules and statements in Appendix-K, dealing with criteria for ECCS-models, are modelled. In this thesis an improved model of a Swedish Boiling Water Reactor within TRACE is realized and tested. Afterwards, once a working and representative model has been obtained, a sensitivity study in conducted in order to investigate the sensitivity of TRACE for a couple of thermal hydraulic parameters. The sensitivity study is focussing on the eect of the peak cladding temperature, as well as the coolability of the nuclear fuel in terms of quenching and quench-front velocities. It is found to be hard to say unilaterally what the eect of changing a certain number of parameters on the reactor behaviour is. As it turns out to be, although strongly related, the peak cladding temperatures and the quench phenomena can behave dierently

The goal of the present study is to investigate the effect of different scenarios of core degradation in a Nordic-type BWR (boiling water reactor) on the reactor pressure vessel failure mode and timing. Specifically we consider the effects of (i) in-vessel pressure, (ii) melt properties. Control rod guide tube (CRGT) cooling and cooling of the debris from the top are considered as severe accident management (SAM) measures in this study. We also consider the question about minimal amount of debris that can be retained inside the reactor pressure vessel (RPV). Analysis is carried out with coupled (i) Phase-change Effective Convectivity (PECM) model implemented in Fluent for prediction of the debris and melt pool heat transfer, and (ii) structural model of the RPV lower head implemented in ANSYS for simulation of thermo-mechanical creep. The coupling is done through transient thermal load predicted by PECM and applied as a boundary condition in ANSYS analysis. Results of the analysis suggest that applying only CRGT and top cooling is insufficient for maintaining vessel integrity with 0.4 m deep (~12 tons) corium melt pool. The failure of the vessel by thermally induced creep can be expected starting from 5.3 h after the dryout of the debris bed in the lower plenum. However, earlier failure of the instrumentation guide tubes (IGTs) is possible due to melting of the nozzle welding. The internal pressure in the vessel in the range between 3 to 60 bars has no significant influence on the mode and location of the global RPV wall failure. However, depressurization of the vessel can delay RPV wall failure by 46 min for 0.7 m (~ 30 tons) and by 24 min for 1.9 m (~ 200 tons) debris bed. For 0.7 m pool case, changes in vessel pressure from 3 to 60 bars caused changes in liquid melt mass and superheat from ~18 tons at 180 K to ~13 tons at 100 K superheat, respectively. The same changes in pressure for 1.9 m case caused changes in liquid melt mass and superheat from ~40 tons at 42 K to ~10 tons at about 8 K superheat, respectively. Investigation of the influence of melt pool properties on the mode and timing of the vessel failure suggest that the thermo-mechanical creep behavior is most sensitive to the thermal conductivity of solid debris. Both vessel wall and IGT failure timing is strongly dependent on this parameter. For given thermal conductivity of solid debris, an increase in Tsolidus or Tliquidus generally leads to a decrease in liquid melt mass and superheat at the moment of vessel wall failure. Applying models for effective thermal conductivity of porous debris helps to further reduce uncertainty in assessment of the vessel failure and melt ejection mode and timing. Only in an extreme case with Tsolidus, Tliquidus range larger than 600 K, with thermal conductivity of solid 0.5 W∙m‑1∙K‑1 and thermal conductivity of liquid melt 20 W∙m‑1∙K‑1, a noticeable vessel wall ablation and melting of the crust on the wall surface was observed. However, the failure was still caused by creep strain and the location of the failure remained similar to other considered cases. / APRI-8