No description available.

This study investigates the impact of wind power on tourism on Gotland. The main objective is toidentify how tourists on Gotland during their holidaying perceive the visual features associated withwind turbines in the landscape. Additionally, it is sought to establish whether tourists plan to return toGotland despite the presence of wind power installations, with a special focus on first-time tourists.Using a structured questionnaire technique on a sample size of 735 respondents, this study reveals that8% of tourists perceive wind turbines negatively. Next, the study identifies that the decision to returnto Gotland of absolute majority of tourists, including first-time visiting tourists, is not impacted by thepresence of wind turbines. Lastly, it has been concluded that a potential on the island exists to developa form of ‘wind power tourism’.

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Biodiversity and ecosystem service losses driven by land-use change are expected to intensify as a growing and more affluent global population requires more agricultural and forestry products, and teleconnections in the global economy lead to increasing remote environmental responsibility. By combining global biophysical and economic models, we show that, between the years 2000 and 2011, overall population and economic growth resulted in increasing total impacts on bird diversity and carbon sequestration globally, despite a reduction of land-use impacts per unit of gross domestic product (GDP). The exceptions were North America and Western Europe, where there was a reduction of forestry and agriculture impacts on nature accentuated by the 2007-2008 financial crisis. Biodiversity losses occurred predominantly in Central and Southern America, Africa and Asia with international trade an important and growing driver. In 2011, 33% of Central and Southern America and 26% of Africa's biodiversity impacts were driven by consumption in other world regions. Overall, cattle farming is the major driver of biodiversity loss, but oil seed production showed the largest increases in biodiversity impacts. Forestry activities exerted the highest impact on carbon sequestration, and also showed the largest increase in the 2000-2011 period. Our results suggest that to address the biodiversity crisis, governments should take an equitable approach recognizing remote responsibility, and promote a shift of economic development towards activities with low biodiversity impacts.

M. Tech. (Department of Civil Engineering and Building, Faculty of Engineering and Technology), Vaal University of Technology / Growth in land development in South Africa resulted in large increase in traffic volumes. A Traffic Impact Assessment (TIA), as a traffic engineering tool, is commonly used to assess the possible effects of a land development project on the transportation and traffic system. During the TIA process, capacity analysis is performed to indicate the measures of effectiveness of the intersection. Intersection capacity analysis in South Africa by engineers is done on the basis of default values of the Peak Hour Factor (PHF) provided by the Highway Capacity Manual (HCM) or limited traffic counts. However, the default value of PHF may be significantly affected by new developments in the neighbourhood of the intersection. This study aimed at investigating the impact land-use change has on the existing intersection PHF, thus predicting values per land-use type. Intersections with traffic counts conducted before and after land-use change in vicinity were selected and investigated. The results showed that change in land-use has an impact on the existing PHF. They also assist in identifying the appropriate intersections to predict the PHF per land-use type. Intersections were identified and analysed, and this led to the development of a design chart showing the predicted PHF per land-use type selected and measures to consider during traffic analysis. Intersection capacity analysis was performed to compare the results using the predicted PHF and the HCM default values. The results showed that traffic flow rate was adjusted by up to 26% when using the default values, 0.92 and 0.95. The results also showed that the default values could overestimate the volume to capacity ratio and the average delay by up to 15% and 35%, respectively. It was then concluded that the use of HCM default values of the PHF for every land-use type will have an effect of the final roadway design results. The computed PHF values for each land-use type were then recommended to be used to ensure fairness and consistency in traffic analysis.

Les composites thermoplastiques sont de plus en plus privilégiées dans les structures aérospatiales au vue de leur tolérance aux dommages améliorée par rapport aux résines thermodurcissables. Néanmoins, ils restent sensibles à l’impact car il produit des endommagements complexes au sein du matériau, dont le délaminage est le plus critique. La propagation de ces endommagements en compression après impact (CAI) entraîne une réduction de la tenue résiduelle. D’abord, des essais ENF ont été menés afin de déterminer la ténacité interfaciale par le biais de la méthode de la complaisance et de la technique de thermographie infrarouge. Ensuite, l’essai « Short Beam Shear » est proposé afin d’investiguer le couplage entre la fissuration matricielle et le délaminage. L’effet de la vitesse de sollicitation a été également étudié. La valeur de ténacité mesurée semble indépendante à la vitesse de sollicitation car, lors des essais réalisés, la propagation est instable. Ensuite, le comportement d’une éprouvette académique été étudié à l’aide du « Discrete Ply Model » (DPM) permettant d’enchaîner la simulation d’impact et de CAI. Ce modèle est basé sur une approche semi-discrète modélisant le délaminage et la fissuration matricielle par des éléments cohésifs, permettant de prendre en compte le couplage entre ces deux endommagements. Une vaste campagne d'essais expérimentaux d’impact et de CAI a été mise en place sur quatre empilements différents impactés à trois niveaux d’énergie. Le modèle DPM a prouvé sa capacité à prédire correctement les endommagements d’impact et de CAI. Finalement, afin de se rapprocher des conditions de structures réelles, le comportement en compression après impact d’une plaque trouée a été investigué. / High-performance thermoplastic composite have been increasingly used in aerospace applications because of their advantageous mechanical properties. Nevertheless, impact damage leads to significant reduction in structure compressive strength although damage may remain unnoticed. Delamination is the most critical damage. Short Beam Shear (SBS) test has been proposed to reproduce impact damage chronology and characterize delamination toughness. Infrared thermography is used for local measuring of fracture toughness in this unclassical test showing unstable fracture growth. Mode II fracture toughness (GIIC) values are comprised between 0.9 and 1.7 N/mm and there was no influence of the loading rate in GIIC values. Discrete Ply Model (DPM) is therefore used to model impact and compression after impact tests on laminated composite structures. Tests have been conducted in order to validate DPM capacity to capture the effects of progressive damage and failure. Impact damage and specimen’s compressive strength is well predicted by DPM. CAI damage propagation is driven by the buckling of the structure. DPM is finally employed to study impact on an industrial sample with a large diameter hole. Impact damage correlates with tests but buckling is difficult to estimate, meaning that rupture of the specimen does not correlate to tests. Nevertheless, DPM shows a good ability to predict damage in thermoplastic composite.

Thesis advisor: Marc Snapper / Discoveries in organic chemistry have had profound impacts in many disciplines of science through the past century. Within the field of organic chemistry, research in total synthesis of natural products has provided a means of developing and advancing the study of different types of chemistry. The discovery of novel chemical transformations, use of total synthesis products in biochemical assay studies and structural studies of natural products are just a few examples of how total synthesis has influenced modern day chemistry. Developments in drug discovery such as the syntheses of penicillin and Taxol have led to applicable use of the science to help the greater global community. Total synthesis provides a means for chemists to use creativity and ingenuity to further develop knowledge of bioorganic compounds and to develop novel chemical transformations useful in medicinal chemistry. Within this paper, total synthesis will be illustrated as the most crowning achievement of modern day organic chemistry based on the earliest total syntheses, modern day total syntheses, the development of novel chemical reactions and its applicability to chemical biology research. / Thesis (BS) — Boston College, 2011. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: College Honors Program. / Discipline: Chemistry.

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Le développement des nanotechnologies passe par la mise au point de nouveaux instruments adaptés à la caractérisation de la matière à l'échelle nanométrique. Le Nanoprobe acquis par l'IEMN au début de ma thèse répond à cet enjeu. Cet instrument constitué d'une plateforme de Microscopie à Effet Tunnel à Quatre-Pointes (4T-STM) et surmontée d'un Microscope Électronique à Balayage (MEB) a pour vocation d'effectuer des analyses, contrôles et tests de nanomatériaux et composants électroniques.Après une description détaillée du fonctionnement de cet appareil (chapitre 2), une première étude a été réalisée pour déterminer l'influence de l'irradiation électronique sur des nanostructures semi-conductrices, à savoir ici des nanofils d'InAs (chapitre 3). Sous irradiation, les fils deviennent quasi-métalliques. Grâce à des mesures originales du transport dans des nanofils semi-suspendus, ce changement des propriétés électriques est attribué à la formation de défauts chargés à la surface des fils. L'ionisation par impact est un phénomène responsable de la multiplication des porteurs dans les cellules photovoltaïques. Le quatrième chapitre démontre l'intérêt du Nanoprobe à caractériser ce phénomène sur un système modèle, une jonction p-n de silicium. Alors que deux pointes en contact polarisent la diode, une troisième injecte localement par effet tunnel des électrons possédant une énergie bien définie. La mesure de porteurs supplémentaires démontre le phénomène d'ionisation par impact avec une résolution inégalée jusqu'à présent. / The advent of nanotechnology involves the development of an instrumentation capable of investigating the matter at this scale. The Nanoprobe acquired by IEMN at the beginning of my thesis brings technical solutions to this issue. This instrument consisting of a Four-Tip Scanning Tunneling Microscopy platform (4T-STM) and topped with a Scanning Electron Microscope (SEM) is dedicated to perform analysis, inspections and tests on nanomaterials and electronic devices. After a detailed description of this instrument (Chapter 2), a first study was conducted to determine the influence of electron irradiation on semiconductor nanostructures, InAs nanowires are treated here. Under irradiation, the nanowires become quasi-metallic. Thanks to original transport measurements on freestanding nanowires, this change of the electrical properties is attributed to the formation of charged defects on the surface of nanowires. The impact ionization is a phenomenon responsible for carrier multiplication in solar cells. The fourth chapter shows the ability of the Nanoprobe to characterize this phenomenon in a typical model, a silicon p-n junction. While 2 tips in contact polarize the diode, a third one locally injects tunneling electrons that have a well defined energy. The measurement of supplementary carriers proves that impact ionization occurs and can be measured with a resolution never reached before.

acase@tulane.edu / Background: Early life and learning experiences have the potential to influence a person’s health throughout the lifespan. These influences, for children of low socioeconomic status in the United States, are compounded by the existence of racial and socioeconomic disparities exist in both child health and development. One of the pathways through which early life and learning experiences affect adult health is through educational attainment, which is initially exhibited through school readiness (i.e. how prepared children are for school). Research in this area traditionally focuses on early learning environments and family level dynamics as predictors of school readiness, although evidence suggests that non-academic factors, like child health, and even more distal factors such as neighborhood structural and social context, contribute to how ready a child is for school. While many have theorized about the relation between both physical health and school readiness and neighborhood social context and school readiness, empirical evidence is limited. Objective: The objective of this research was to investigate non-academic factors related to the behavioral and cognitive domains of school readiness (language and literacy, social-emotional, numeracy/cognitive) including physical health and neighborhood social context. Methods: The research was conducted as a mixed methods design: 1) a longitudinal, retrospective matched cohort study, using data from the Educare Learning Network’s 2007-2015 data set which included data from 26,810 children enrolled in 20 Educare schools across the United States with children propensity matched on exposure, either by health status (see Aim 1 p. 15) or parental perceived neighborhood support (see Aims 2-3 p 16); and 2) a qualitative study conducted with parents of children ages 0-5 in New Orleans, Louisiana and aimed at a deeper understanding of parent perceptions of school readiness, neighborhood, child health and the intersection of these concepts. Results: Results from Paper 1 indicate that there is an association between asthma and school readiness outcomes, however this may be confounded by child and family level factors and may also differ by child race or sex. Paper 2 Quantitative results indicate that there is an association between perceived neighborhood support and child health and school readiness, particularly social emotional development, and that these results may differ by child race and sex and that there are significant interactions between neighborhood and race playing a role. Qualitative analysis in Paper 2 indicated common themes of perception of neighborhood, neighborhood safety, and stress and these discussed in relationship to their impact on their children. Paper 3 Results indicate that parental stress and parent-child relationship, individually and in sequence, are mediators of the relationship between perceived neighborhood support and receptive vocabulary scores, but mediation was not significant for other child cognitive, language, and physical health outcomes. Conclusions: Findings from this study contribute to the current understanding of external factors, outside of the early learning environment, that contribute to disparities in child health and school readiness in a vulnerable population. Not only as they relate to childhood, but also to adult health and well-being across the life course. The data will provide empirical evidence to inform programs and policies related to external factors that may impact school readiness for a high quality early education programs. / 1 / Lauren Futrell Dunaway