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  • 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.
781

Three topics to the evolution of the environmetal impact assessment / Tres áreas en la evolución de la regulación del impacto ambiental

Verna Coronado, Vito 10 April 2018 (has links)
The paper identifies three topics in order to evaluate the improvements in the regulation of the National System of EnvironmentalImpact Assessment, looking to benefit the people’s trust in the environmental certification. The first one consists in the gradual transition from the prevention paradigm to the integration one, as the purpose of the different instruments that compose the system; the second involves the enrichment in the evaluation of the Environmental Impact Study (EIS), by incorporating the scoping phase; and the third involves adopting additional measures that reinforce the independence of the teams in charge of the elaboration and evaluation of the EIS. / El artículo identifica tres áreas para evaluar mejoras a la regulacióndel Sistema Nacional de Evaluación de Impacto Ambiental, con miras a favorecer la aparición de confianza ciudadana respecto de la certificación ambiental. La primera tiene que ver con transitar gradualmente del paradigma preventivo al integrativo como finalidad de los instrumentos que componen el sistema; la segunda, con enriquecer la evaluación del estudio de impacto ambiental (EIA) incorporándole una etapa de scoping a cargo del Estado; y la tercera, con adoptar medidas adicionales que refuercen la independencia de los equipos de elaboración y evaluación del EIA.
782

Développement d'un modèle mécanique pour la prédiction des dommages de panneaux composites aéronautiques soumis à un choc foudre / Development of a lightning strike mechanical model for the prediction of damage of aeronautical composite panels

Soulas, Floriane 02 March 2016 (has links)
Dans un contexte industriel où l’utilisation de matériaux composites s’est généralisée jusqu’à atteindre les structures primaires, la menace foudre se révèle être une problématique majeure.Avec un coup de foudre en moyenne par an et par avion en service, les nouvelles structures composites, moins bonnes conductrices que leurs prédécesseurs en métal, doivent être protégées. Les protections mises en œuvre par les fabricants et les équipementiers sont des couches minces ajoutées à l’empilement composite, initialement choisi pour le compromis optimal qu’il offre entre résistance et légèreté. L’optimisation et le conseil concernant les protections foudre deviennent alors un enjeu industriel d’importance. Dans ce cadre, le travail de thèse a porté sur l’étude et la compréhension des dommages issus des chocs foudre sur des structures protégées dans le but ultérieur d’optimiser ou de créer des protections adaptées.Nous proposons une méthode qui permet de déterminer les caractéristiques d’un impact mécanique sur une plaque composite nue, équivalent à un choc foudre sur une structure protégée. Une campagne d’essais d’impacts avec un canon du laboratoire couplé à une campagne numérique ont permis de conclure que la stratégie et la méthode d’équivalence sont fondées, et permettent de prendre en compte les paramètres constitutifs de la protection de surface. Les modèles proposés permettront d’aborder les questions de conception des protections. / In an industrial context where more and more composite materials are integrated into primary structures, the lightning threat has become a major issue for aircraft manufacturers. As lightning strikes in service airplane about once a year, the new composite structures, with a lower electrical conductivity than their metallic predecessors, must be protected. The protections already integrated by manufacturers are mainly made of expanded metallic foil layered above the composite lay-up, thus adding weight on the low density structures and reducing the gain of weight. The optimization of such structures and counsel concerning lightning protection become a major industrial stake. In the scope of the PhD work, the proposed work focused on the study of the damage mechanisms due to lightning strikes on protected composite panels in order to optimize or offer adequate protections against this threat. A methodology is proposed to determine a mechanical impact on a bare composite plate equivalent to a protected and even painted structure submitted to a lightning impact. An experimental campaign of mechanical impacts using a canon gas gun coupled to a numerical plan is led and allows concluding on the strategy and its validity by taking into account the state surface of the lightning samples.
783

Vliv cestovního ruchu na podnikatelské aktivity a rozvoj města Český Krumlov / The impact of tourism on business activities and development of the city Český Krumlov

ŠMELC, Petr January 2012 (has links)
The objective of the diploma thesis was to evaluate the impact of tourism on business activities and development of the city Český Krumlov. Under the analysis of various statistical data the trend of the number of incoming visitors, the economical contribution of tourism on the city, private businesses and citizens were specified. To evaluate the impact of tourism on private businesses and citizens various subjects were questioned via questionnaire online and also during the field research. Under the determined results main problems of the city related to the development of tourism were specified and there were suggestions proposed for the future improvement.
784

Contribution à la caractérisation de la déformation et de la rupture dynamique de structures sous impact : Modélisations et approche expérimentale / Contribution to the characterization of the dynamic deformation and fracture of a structure Under impact : modeling and experimental approach

Antoinat, Léonard 21 November 2014 (has links)
L'objectif de ces travaux de thèse est de proposer des approches de modélisation et d'expérimentation de l'impact de structures déformables et indéformables sur différents milieux. Différents modèles analytiques et des simulations numériques sont développés en comparaison aux résultats expérimentaux. Une première partie se consacre à la caractérisation de la similitude entre la réponse à l'impact à l'eau d'un solide et la réponse d'un solide impactant une structure déformable. Des simulations éléments finis (EF) et SPH sont réalisées pour l'impact à l'eau d'un tube cylindrique (sans rupture). Un modèle analytique d'impact à l'eau est proposé pour prédire l'évolution de l'effort (pic, durée). L'analyse des résultats permet de dimensionner un programmateur d'impact solide reproduisant le pic d'effort. Des simulations EF de l'impact sur un tube cylindrique, à géométrie adapté, dans la direction longitudinale, sont réalisées et comparées à quelques expériences tests. Le «flambage dynamique» (dû au comportement inélastique du matériau et aux ondes de déformations) des tubes est alors observé. Une seconde partie traite du cas de la perforation sous impact d'une tôle mince à faibles vitesses d'impact (< 10 m/s, vitesse de déformation < 1000 s-1). Des essais sur puits de chute instrumenté (force, déplacement, déformée de tôle, avancée de fissure) sont analysés. Des simulations EF en éléments coques avec un critère de rupture ductile par endommagement sont réalisées. Les paramètres de rupture dynamique sont identifiés par méthode inverse à l'aide d'essais de résilience Charpy sur l'alliage d'aluminium de désignation 2024 T3. Une analyse des pics de force lors de l'impact permet une meilleure compréhension des mécanismes de perforation. En parallèle, un nouveau modèle analytique, basé sur les énergies impliquées lors de l'impact, est proposé et comparé aux simulations EF. L'étude numérique de la perforation est étendue aux grandes vitesses d'impact et de déformation (100 - 1000 m/s, vitesse de déformation <100 000 s-1) pour identifier les transitions des différents mécanismes de perforation connus (pétalisation, fragmentation des pétales, fragmentation complète). / The objective of this work is to propose approaches to model and to assess experimentally the structural impact on different media. A variety of analytic models and numerical simulations are developed comparing to experimental results. The first part of this work presents a discussion on the similitude between a water impact and an impact on a deformable solid structure. Water impact simulations of a deformable cylinder (without rupture) are performed by finite elements (FE, Coupled Eulerian Lagrangian) and SPH analysis. An analytical model of water impact is proposed for the prediction of peak force evolution. The analysis of results permits to design an impact programmer reproducing this peak force. FE longitudinal impact simulations on cylindrical tubes, with an adapted geometry, are performed and compared with some experiments. The “dynamic buckling” of tubes under impact (due to the material inelastic behavior and to strain waves) is observed. The second part deals with the low velocity perforation (< 10 m/s, strain rate < 1000 s-1) of thin plates. Some experiments on an instrumented drop test (force, displacement, plate shape, crack propagation) are analyzed. Shell FE simulations, with a damage rupture criteria implemented are performed. Parameters are identified by inverse method with the help of Charpy tests made on 2024 T3 aluminum alloy. An analysis of the peak force, during impact, leads to a good understanding of the perforation mechanism. In parallel, a new analytical model, based on an energetic approach of the perforation, is proposed and compared with FE simulations. The numerical perforation study is extended to high velocities and high strain rates (100 - 1000m/s, strain rate < 100 000 s-1) in order to identify different well-known transitions of perforation (Petalisation, petals' fragmentation, total plate's fragmentation).
785

Impact of particle-laden drops on substrates with various wettability

Grishaev, Viktor 19 May 2015 (has links)
Since decades, drop impact has been a popular topic of investigation for the importance that such a phenomenology has in many different application domains.<p><p>So far, the effect of micro-particles on the drop impact morphology has been studied for a limited number of configurations and often modelled as a change in the viscosity of the carrier fluid. However, this approach has been found sometimes questionable. The aim of the thesis is to better understand the phenomenology associated with particle-laden drop impact such as the distribution of particles in splats and to extend the number of experimental configurations for particle-laden drop impact to occur.<p><p>The impact of millimetre-size particle-laden drops was investigated for hydrophilic and hydrophobic substrates. The drops were dispersions of water and round, spherical and nearly iso-dense hydrophobic particles with diameters around 200 µm and 500 µm. The substrates were transparent glass and polycarbonate plates. The impact was studied by side, bottom and angle view images in the range 148≤We≤744 and 7092≤Re≤16368.<p><p>The particles were found to suppress the appearance of singular jetting and drop partial rebound, and also cause early splashing, receding break-up and rupture. The occurrences of these phenomena depend on the impact velocity, particles’ diameter and volume fraction. The drops with 200 µm particles spread in two phases: fast and slow, caused by inertial and capillary forces, respectively. Also, the increase of volume fraction of 200 µm particle leads to a linear decrease of the maximum spreading factor caused by the inertia force on the hydrophilic and hydrophobic substrates. The comparison of our data and the existing ones for splashing led to the formulation of а new splashing criterion for particle-laden drops. The novel criterion improves upon current models in predicting the splashing threshold by introducing effect of particle volume fraction and particle wettability. The analysis of particle distribution showed that 200 µm particles formed atypical distributions in splats after the impact in contrast to 500 µm particles with random pattern. The 200 µm particles formed rings/disks and a crown-like structure on hydrophilic and hydrophobic substrates, respectively. These patterns were described by correlations.<p> / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished
786

Social and economic impact of coastal tourism in Kalmar, Sweden

Fan, Wanting January 2017 (has links)
Coastal tourism is one of the most important way of leisure and entertainment in the world, which brings impact in varying degrees to the tourism destination. These effects relate to economic, social, and environmental aspects. With the concept of sustainability being widely used, sustainable tourism has received more attention. However, most studies focus on the tourism impact on the coastal environment, while the social and economic aspects were sparse explorations. Therefore, this research applies the qualitative method to explore the social and economic impact of tourism on the coastal city, Kalmar. Furthermore, the perspective of residents and business owners is the main way to reflect these effects. According to the results of the study, the development of the tourism industry will indeed bring some impact to the coastal city on economy and society. However, due to differences of cultural background and actual situation, these effects are not always the same. For example, for the economic impact of tourism business, the impact on the hotel is more noticeable than the impact on restaurants and bars.
787

Sustainable project life cycle management : development of social criteria for decision-making

Labuschagne, Carin 11 October 2005 (has links)
An initial analysis of sustainable project life cycle management methodologies’ current status highlighted that social and environmental aspects of sustainable development are not addressed effectively. An acceptable model aimed at addressing the various sustainable development aspects from a project management perspective is thus needed. This study’s main research objective was consequently to develop the different elements of such a model for social business sustainability. The research focused on the three main research questions discussed below. Which lifecycles should be considered when evaluating the project’s possible impacts? Projects implement or deliver certain products, which in turn, can produce other commodities sold by the company. The three lifecycles, i.e. project, asset and product, were studied to determine which lifecycles to consider when evaluating projects’ possible impacts. It was concluded that it is specifically the project’s deliverables and its associated products that have economic, social and environmental consequences. These life cycles must therefore be considered as part of the project life cycle when evaluating social impacts. What social business sustainability impacts or aspects should be considered in the project life cycle? A sustainable development framework that can be applied to projects directly to ensure their alignment with sustainable development does not exist at present. A social sustainability assessment framework as part of a sustainability assessment framework for operational initiatives was consequently developed and introduced. The social framework was verified and validated by means of case studies, a survey and a Delphi Technique case study to test the framework’s completeness and relevance. How should project management methodologies be adopted to ensure incorporation of social business sustainability? The research indicated that the various social aspects are addressed in different ways in the individual asset life cycle phase. The social criteria in the framework should therefore also be addressed in different ways in the project management methodologies. A Social Impact Indicator (SII) calculation procedure, based on a previously introduced Life Cycle Impact Assessment (LCIA) calculation procedure for environmental Resource Impact Indicators (RIIs), was developed as a method to evaluate social impacts in the project life cycle phases. Case studies in the process industry and statistical information for South Africa have been used to establish information availability for the SII calculation procedure. / Thesis (PhD (Engineering Management))--University of Pretoria, 2006. / Graduate School of Technology Management (GSTM) / unrestricted
788

Investing for a Brighter Future :  A qualitative study of the management of impact investing in emerging markets.

Berglund, Karl, Björnbom, Mårten, Rosander, Anton January 2020 (has links)
The purpose of this thesis is to gain a deeper understanding of the term impact investing and examine how Nordic impact investors manage risk, return, and social and/or environmental in emerging markets. Relevant aspects to impact investing have been identified to enable this thesis to be conducted. The thesis derives from a qualitative research method, this to gain a deeper understanding of the term and how Nordic impact investors conduct their business in emerging markets. The thesis is based on a deductive research approach due to that the term impact investing has a limited amount of previous research.   The literature review highlights relevant theories related to the research questions. The concepts presented are impact investing, emerging markets, dual interest, and risk management. These theories have later been put into a conceptual framework to showcase the interconnections. From the conceptual framework, three main concepts (impact investing, dual interest, and risk management in emerging markets) have been established and then later analysed based on the empirical data gathered from a multi-case study.   The analysis chapter includes a comparison and discussion between the empirical findings and the literature review in order to answer the thesis research questions. Furthermore, the analysis follows the same concepts presented in the operationalization. The final chapter reveals the conclusions drawn based on the analysis conducted. The final chapter further highlight implications both theoretical and practical, followed by suggestions for future research. The theoretical implications of the thesis pinpoint that impact investing require conceptual clarity to raise more awareness and gain recognition. Furthermore, risk management is an essential part of conducting investments in emerging markets. The practical implications showcase that impact investing can be conducted in several different ways and that there are no distinct patterns on how to manage impact investments best. Furthermore, the thesis stresses the importance of impact investing in emerging markets.
789

The Gatun Structure: A geological assessment of a newly recognized impact structure near Lake Gatun in the Republic de Panama

Tornabene, Livio Leonardo 01 November 2001 (has links)
The Gatun Structure (N 09º 05’ 58.1”, W 79º 47’ 21.8”, situated in the triple-canopy rainforest 10 km to the WSW of the Gamboa and about 2 km south of the Isle of Barbacoas, Republic de Panama), is a partially inundated, quasi-concentric surface feature ~3km in diameter, which appears in aerial photographs and in radar imagery as an arcuate chain of islands with a raised center. Although the structure has been heavily weathered and altered, it has retained morphology consistent with complex craters: an elevated circular central uplift 500-600 m in diameter and approximately 70 m high, and arcuate boundary ridges (a rim structure?) ranging from ~50-110 meters high. Within the central peak, highly altered and fractured siltstone of the Gatuncillo Formation (?) (Eocene) ± older rocks are uplifted and exposed through surrounding calcareous units of the Caimito Formation (Oligocene) and the Las Cascadas Formation (Miocene), the major target rocks in the region. Lithologies in the structure include highly fractured siliciclastic rocks (siltstone, sandstones and greywackes), limestones with anomalous spherical glass inclusions, both black and white hypocrystalline glasses (possible melt rocks), lithic fragmental breccias, and melt-bearing breccias (possible impact melt breccias and suevites) containing flow banding and evidence for selective melting of minerals. Three types of spherules (glass, fluid-drop and lithic), a pyroxenequartz “necklace” disequilibrium structure (coronas), plagioclase feldspars exhibiting mosaicism and partially amorphization and zeolitization, possible liquid immiscibility between melts of calcite and felpspathic glass, as well as decomposition of titano-magnetite, are all petrographic criteria that suggest a hypervelocity impact event. The structure is crosscut by numerous dikes of unshocked basalt and basaltic andesite related to volcanism along the Panamanian segment of the Central American arc to the south. However, the lithologies of the Gatun Structure are chemically inconsistent with the regional volcanic rocks and the unshocked volcanic rocks that crosscut the structure. An impact origin is our preferred interpretation for the Gatun structure due to the lack of an igneous relationship between the Gatun structure and the explosive volcanism of Panamanian arc, the presence of classical impactite lithologies within the site, the occurrence of spherules, maskelynite (as suggested by Raman Spectroscopy) and other disequilibrium shock features in the Gatun suite of rocks.
790

Elevers erfarenheter av olika undervisningsstilar : En kvalitativ fallstudie om elevers erfarenheter av undervisningsstilar i idrott och hälsa

Sandström, Christoffer January 2022 (has links)
Syftet med denna uppsats är att undersöka hur sex elever uppfattar sin undervisande lärares undervisningsstilar i idrott och hälsa. Studien fokuserar även på hur delaktiga eleverna får vara vid planering, genomförande och utvärdering av en lektion. I litteraturgenomgången har jag använt mig utav litteratur, forskning och Skolverket för att få en djupare bild av hur elevers erfarenheter ser ut av just undervisningsstilar. Jag har tagit utgångspunkt i Musska Mosstons elva olika undervisningsstilar. I denna kvalitativa fallstudie har semi-strukturerade intervjuer använts som metod för att forska kring undervisningsstilar. Sex intervjuer har genomförts med elever som går i årskurs nio. Det resultat som framkom genom studien var att reproduktiva undervisningsstilar är mest förekommande i planeringsstadiet. I genomförandefasen av en lektion är det mer produktiva stilar som blir framträdande samt att i utvärderingsfasen av en lektion så är det mer reproduktiva stilar som används för dessa elever. / The aim of this study is to investigate students perceptions about teaching styles in physical education. The study’s focus is also how involved students are within the pre-impact phase, the impact phase and the post-impact phase. When I have been searching for information, I have been using literature, research and Skolverket to get a deeper picture of how students perceptions are about teaching styles, you can read about this in the literature review. In this study, as starting point I have taken Musska Mosston’s eleven different teaching styles.  In this study, I have used qualitative semi-structured interviews with six students about teaching styles. The interviewed students are going in the ninth grade.  The result of this study is that when pre-impact, the reproductive teaching styles is more prominent. When impact, productive teaching styles is more dominant. When post-impact of a lesson, reproductive teaching styles is more dominant for these students.

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