This study was undertaken in order to obtain an understanding of how Namibia in general, and the education sector in particular, deal with flood emergencies. The goal of the National Policy for Disaster Risk Management in Namibia (2009) is “to contribute to the attainment of sustainable development in line with Namibia’s Vision 2030 through strengthening national capacities to significantly reduce disaster risk and built community resilience to disasters” (Republic of Namibia, 2009). This goal was the starting point for determining the extent to which the Ministry of Education complies with these national standards, and for gauging, in the light of responses to flood emergencies so far, the Ministry’s preparedness and response capacities, in line with international frameworks that Namibia has ratified. This qualitative study is situated within the theory of resilience, and sustainable resilience particularly. To obtain some of the information sought, a non-probability sampling method was used to ‘hand-pick’ subjects within the Ministry of Education to be interviewed at their respective locations, nationally and regionally. Five education officials who were intimately involved in past responses to flood emergencies were interviewed – three in Oshana and Ohangwena Regions, and two at Head Office in Windhoek – by means of a semi-structured interview. In addition, a literature review was conducted. The conclusions drawn from both the literature review and the information obtained from the respondents accord with the research problem identified: the Ministry of Education does not appear to be adequately prepared for, and does not assign the necessary priority to deal with, flood emergencies in particular. Possible recommendations for uptake within the Ministry of Education include: mainstreaming Disaster Risk Reduction at all decentralized levels; sensitizing all education officials, school community members and relevant stakeholders to policy frameworks and accountability structures to strengthen resilience within school communities; deeming costed contingency planning a priority, and hence strengthening links between decentralized regional structures; and continuously monitoring implementation of designed interventions.

No description available.

This thesis is concerned with the use of semi-active suspensions in heavy vehicles to improve ride and reduce road damage. An introduction into the subject is given in chapter 1 and a review of the relevant literature is presented at the beginning of each main chapter. The development and modelling of a prototype, continuously variable semi-active damper for heavy vehicles is described in chapter 2. A proportional valve is used to generate the variable damping coefficient and the detrimental effects of the oil flow forces acting on the valve spool are studied. The force tracking performance of the damper is then examined for simple input conditions and the compliance of the hydraulic fluid is found to have a strong influence upon the response of the damper. The different vehicle and road models used in the thesis are described in chapter 3. In chapter 4, the performance of the prototype damper is investigated under realistic operating condition using a Hardware-in-the-Loop (HiL) test rig, with a single wheel station vehicle model. The prototype damper displays a phase lag of approximately 20ms between the demanded and achieved damping force. The semi-active suspension is found to be most effective in reducing the body accelerations relative to an optimum non-linear passive suspension. A theoretical investigation into the reduction of road damage through the use of active and semi-active suspensions is described in chapter 5. The relative performance of four linear state feedback control strategies is examined. The potential for reducing road damage by using a controller which directly regulates various measures of road damage is also studied. Significant improvements are predicted for the three controllers which assume the road inputs to the vehicle are correlated. However, these benefits are shown to diminish as the vehicle speed is reduced. It is concluded that the control of the dynamic tyre forces is an effective means by which to regulate road damage. Theoretical predictions of the benefits from wheelbase preview control are measured experimentally in chapter 6, using the prototype semi-active damper in a half-car HiL rig with a planar two axled heavy vehicle model. The benefits of preview control using the prototype semi-active damper are found to be less than theoretically possible due to the phase lag between the demanded and achieved damping force of the prototype damper. The final section of chapter 6 shows that the performance of the prototype damper can be improved further by having a theoretical simulation running ahead of the HiL vehicle. The theoretical simulation is used to predict the demanded damper force for the HiL vehicle and thereby compensate for the phase lag in the prototype damper. Conclusions and recommendations for further work are presented in chapter 7.

The Large Hadron Collider (LHC) at CERN has the highest energy and luminosity in the world. Radiation hardness is then a critical requirement for the inner tracker design. The inner tracker is important for identifying heavy quarks using high spatial precision detectors. Silicon detectors are now the primary technology for this application. 3D silicon sensors use a novel technology with penetrating electrodes and have excellent radiation hardness by design. It overcomes the signal loss with a low operation voltage by reducing the collection length compared to the current planar technology used in the ATLAS pixel detector. The ATLAS insertable B-layer (IBL) is an upgrade to improve tracking resolution of the inner tracker and will be installed in 2013. It will be composed of 75% planar sensors and 25% 3D sensors in the large-η region. It is important to simulate the IBL tracking performance and to have a valid model for 3D sensors. This thesis investigated the experimental data for heavily irradiated planar strip sensors and 3D sensors to develop a device simulator, in which impact ionisation has to be included. The modelling has found that the radiation induced effective doping concentration has two linear regimes with a smaller growth rate at high fluences. This shows the possibility to operate silicon sensors with a higher irradiation level. The signal efficiency of each pixel is the basis to simulate the whole IBL response. A model and a code were developed to calculate the induced signal from electron-hole pairs generated by the traversing charge particles. This results in a 2D efficiency map used as an input of the 3D digitiser for the Geant4 simulation. This map was adopted by the IBL software team for the whole tracker simulation and has been validated by the test beam data.

Modelling damage in composite materials has played an important role in designing composite structures. Although numerical models for the progressive damage in laminated composites (e.g. transverse cracking, delamination and fibre breakage) have been developed in the literature, there is still a need for further improvement. This thesis aimed at developing damage models suitable for predicting intra-laminar and inter-laminar damage behaviour in fibre-reinforced composite materials. Several approaches such as fracture mechanics and continuum damage mechanics have been adopted for constructing the damage model. Meso-macro-mechanics analysis was performed to gain an insight into the entire damage process up to the final failure of the composite laminate under various conditions. Cohesive elements were placed in the finite element model to simulate the initiation and propagation of matrix crack and delamination in cross-ply laminates. This helped to understand the direct interactions between damage modes, i.e. whether one damage mode would initiate the other damage mode. The formation of a single matrix crack and its propagation across the layer thickness was also revealed. A new cohesive zone/interface element model was developed to consider the effect of through-thickness compressive stress on mode II fracture resistance by introducing friction into the constitutive law of the conventional cohesive zone model. Application of the model to practical problem in composite laminates shows that this model can simulate delamination failure more accurately than the cohesive element in ABAQUS.Damage models based on continuum damage mechanics were proposed for predicting intra-laminar damage and interlaminar damage. Five intra-laminar failure modes, fibre tension, fibre compression, matrix tension, matrix compression and shear failure, were modelled. Damage initiation was predicted based on stress/strain failure criteria and damage evolution law was based on fracture energy dissipation. The nonlinear shear behaviour of the material was considered as well. These models have been implemented into ABAQUS via a user-defined material subroutine and validated against experimental/numerical results available in the literature. The issue related to numerical implementation, e.g. convergence in the softening regime, was also addressed. Numerical simulation of the indentation test on filament-wound pipe was finally conducted and damages generated in the pipe were predicted using the above developed damage models. The predictions show an excellent agreement with experimental observations including load/indentation responses and multiple delaminations shape and size. Attempt was made to detect damage-induced leakage path in the pipe after indentation.

No description available.

Thermoplastics reinforced with continuous fibers are very promising building materials for the auto industry and consumer electronics to reduce the weight of vehicles and portable devices, and to deliver a high impact tolerance at the same time. Polypropylene is an abundant thermoplastic, and its glass fibers composites make a valuable solution that is suitable for mass production. But the adoption of such composites requires a deep understanding of their mechanical behavior under the relevant loading conditions. In this Ph.D. work, we aim to understand the damage process in continuous glass fiberreinforced polypropylene in detail. We will focus in particular on developing an approach for microscale observation of damage during the out-of-plane loading process and will use these observations for both qualitative and quantitative evaluation of the composite. We will apply our approach to two kinds of polypropylene composites, one of them is specially designed to withstand impact. The comparison between the two types of composites at slow and fast loading cases will shed some light on the effect of the polymer properties on the behavior of composites under out-of-plane loading.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22736号 / 医博第4654号 / 新制||医||1046(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 小川 誠司, 教授 武藤 学, 教授 滝田 順子 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Electronic Nicotine Delivery Systems (ENDS) are methods of delivering nicotine without combustion, which happens in cigarettes. These devices consist of a heating element, a battery, and a tank which stores eliquid. Over the years these devices have become more powerful, and capable of increased delivery of nicotine. There is a large variety of flavors and devices, which causes trouble for standardized studies. These devices were created to help cigarette users quit smoking; however, they are associated with significant dual use. ENDS produce lower levels of most toxic chemicals when compared to cigarettes, and significantly increased levels when compared to not smoking. Newer generation ENDS have capabilities of producing levels of reactive oxygen species and carbonyl compounds at levels similar to cigarettes. ENDS use has detrimental effects on the genome, immune system, and lung function due to exposure from these chemicals. These effects are at lower levels when compared to cigarette use. Chronic ENDS use has been associated with chronic obstructive pulmonary disorder (COPD), with an even higher association with dual use. ENDS use also causes DNA adduct formation, and activates protein kinases, nicotine acetylcholine receptors and other pathways for lung cancer as cigarette use. The full health effects of ENDS use are still unknown, from the currents studies it is clear that its use is not without harm.

It is well known that the formation and propagation of microcracks within concrete is anisotropic in nature, and has a degrading effect on its mechanical performance. In this thesis an anisotropic damage mechanics model is formulated for concrete which can predict the behavior of the material subjected to monotonic loading, fatigue loading, and freeze-thaw cycles. The constitutive model is formulated using the general framework of the internal variable theory of thermodynamics. Kinetic relations are used to describe the directionality of damage accumulation and the associated softening of mechanical properties. The rate independent model is then extended to cover fatigue loading cycles and freeze-thaw cycles. Two simple softening functions are used to predict the mechanical properties of concrete as the number of cyclic loads as well as freeze-thaw cycles increases. The model is compared with experimental data for fatigue and freeze-thaw performance of plain concrete. / DOT-MPC grant / Department of Civil Engineering, North Dakota State University