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1
Ciccone, Giuseppina. "Experimental study of artificial blocks under dynamic fragmentation." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018.
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Rockfall represents a significant hazard not only in mountainous areas, but also alongside coastal routes, major transport infrastructures and quarry faces.
One aspect of the rockfall phenomenon that still requires further investigations is the fragmentation of falling blocks upon impact. The changes in size, shape and energy of the falling blocks upon fragmentation and the variation in trajectory of the fragments can seriously affect the optimization design of the rockfall mitigation measures. The fragmentation of boulders during a rockfall event can lead to significant changes in the global run-out distances and the maximum kinetic energy to be accounted in the protection systems design.
This thesis presents an experimental program conducted to investigate the fragmentation phenomenon under controlled conditions to provide some useful insights in terms of block survival probability upon dynamic impact, fragments distribution, post impact velocity and energy dissipation upon impact.
The result of this thesis will focus on a detailed description of the fragmentation process and study several fragmentation mechanisms involved, reproducing many experimental observations of fragment shapes and impact energy, and significantly improve the understanding of the fragmentation process for impact fracture.
Spheres shapes were chosen because of their simple body geometry and consequent impact and stress field symmetry. So, the description of materials, sample preparation and tests program conducted for 175 mortar spheres of different diameter built for the current research will be presented to evaluate the survival probability of homogeneous artificial rocks with a known compressive strength dropped from a certain height and to observe the fragmentation process upon impact with a known impacting energy.
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Narwani, Tarun Jairaj. "Dynamics of protein structures and its impact on local structural behaviors." Thesis, Sorbonne Paris Cité, 2018. http://www.theses.fr/2018USPCC160/document.
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Les structures protéiques sont de nature hautement dynamique contrairement à leur représentation dans les structures cristallines. Une composante majeure de la dynamique structurelle est la flexibilité des protéines inhérentes. L'objectif principal de cette thèse est de comprendre le rôle de la dynamique inhérente dans les structures protéiques et leur propagation. La flexibilité des protéines est analysée à différents niveaux de complexité structurelle, du niveau d'organisation primaire au niveau quaternaire. Chacun des cinq premiers chapitres traite un niveau différent d'organisation structurelle locale avec le premier chapitre traitant des structures secondaires classiques tandis que le second analyse la même chose en utilisant un alphabet structurel - les blocs protéiques. Le troisième chapitre se concentre sur l'impact d'événements physiologiques spéciaux comme les modifications post-traductionnelles et le désordre sur les transitions d'ordre sur la flexibilité des protéines. Ces trois chapitres indiquent une mise en œuvre dépendante du contexte de la flexibilité structurelle dans leur environnement local. Dans les chapitres suivants, des structures plus complexes sont prises en compte. Le chapitre 4 traite de l'intégrine αIIbβ3 impliquée dans des troubles génétiques rares. L'impact des mutations pathologiques sur la flexibilité locale est étudié dans deux domaines rigides de l'intégrine αIIbβ3 ectodomaine. La flexibilité inhérente dans ces domaines est montrée pour moduler l'impact des mutations vers les boucles. Le chapitre 5 traite de la modélisation structurelle et de la dynamique d'une structure protéique plus complexe du récepteur des chimiokines des antigènes du groupe Duffy incorporé dans un système de membrane mimétique érythrocytaire. Le modèle est soutenu par l'analyse phylogénétique la plus complète sur les récepteurs de chimiokines jusqu'à ce jour, comme expliqué dans le dernier chapitre de la thèseProtein structures are highly dynamic in nature contrary to their depiction in crystal structures. A major component of structural dynamics is the inherent protein flexibility. The prime objective of this thesis is to understand the role of the inherent dynamics in protein structures and its propagation. Protein flexibility is analyzed at various levels of structural complexity, from primary to quaternary levels of organization. Each of the first five chapters’ deal with a different level of local structural organization with first chapter dealing with classical secondary structures while the second one analysis the same using a structural alphabet - Protein Blocks. The third chapter focuses on the impact of special physiological events like post-translational modifications and disorder to order transitions on protein flexibility. These three chapters indicate towards a context dependent implementation of structural flexibility in their local environment. In subsequent chapters, more complex structures are taken under investigation. Chapter 4 deals with integrin αIIbβ3 that is involved in rare genetic disorders. Impact of the pathological mutations on the local flexibility is studied in two rigid domains of integrin αIIbβ3 ectodomain. Inherent flexibility in these domains is shown to modulate the impact of mutations towards the loops. Chapter 5 deals with the structural modelling and dynamics of a more complex protein structure of Duffy Antigen Chemokine Receptor embedded in an erythrocyte mimic membrane system. The model is supported by the most comprehensive phylogenetic analysis on chemokine receptors till date as explained in the last chapter of the thesis
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Canessi, Tomà. "Physical modelling of rock fragmentation upon impact." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.
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Rockfall represents a significant safety hazard in building, civil and mining environment that can cause serious injuries and fatalities and can damage structures, infrastructure and machinery. It is extremely costly to manage and public authorities need reliable tools to study and design protection structures as the performance of the existing structures are variable. Many studies and experiments have been done, but one aspect would lead to a better comprehension of the subject: the fragmentation of blocks upon impact. Rocks commonly break up upon impact but rockfall prediction models currently available mostly ignore this phenomenon, even though fragmentation changes size, shape and energy of falling blocks and can drastically change the outcome of the design of protective structure. For example, if a large rock breaks upon impact and its mass and energy are divided among fragments, a high level of energy is dissipated and ignoring fragmentation would lead on an overdesign of the protection barrier. Moreover, very fast rock fragments may rupture a rockfall protection. The project aims to overcome this limit, studying and considering fragmentation in rockfall model, allowing assessment of the hazard rising from a shattered rock. The intention is to develop a database of experimental data about fragmentation of blocks upon impact by considering the initial conditions that cause fragmentation, the fragment size and mass distribution, the partition of velocity and energy at impact and what may lead to “bullet effect” or high flying fragment. This project aims to include fragmentation in rockfall prediction causes to facilitate a better and safer mitigation of rockfall hazard. Moreover, a better knowledge will directly translate into economical and societal benefits, such as more cost effective and better user experience.
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Patto, André Luiz Duque Brunini. "Minimização de impactos ambientais com a utilização de resíduos de construção e demolição (RCD) como agregados na fabricação de concreto." Universidade de Taubaté, 2006. http://www.bdtd.unitau.br/tedesimplificado/tde_busca/arquivo.php?codArquivo=95.
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A reciclagem de resíduos de construção e demolição (RCD) é uma prática utilizada desde a Antigüidade, quando cidades destruídas pela guerra e por catástrofes naturais eram reerguidas dos próprios escombros. Hoje, ela é utilizada em larga escala em vários países da Europa e nos EUA. No Brasil, onde a preocupação com o destino desses resíduos é bem mais recente, poucos municípios se preocupam com o gerenciamento dos RCD. Os efeitos disso são visíveis: os resíduos ainda são depositados irregularmente em terrenos baldios, vias públicas, várzeas, córregos e até mesmo em áreas de proteção ambiental, causando a proliferação de vetores nocivos à saúde, enchentes e diversos prejuízos ao meio-ambiente. Assim, este trabalho tem como objetivo propor soluções que busquem a minimização desse impacto ambiental por meio da utilização dos RCD como agregados na fabricação de blocos de concreto. Os testes em laboratório e a comparação dos resultados obtidos com os das práticas convencionais provam a viabilidade da utilização dos resíduos, tanto em termos ambientais quanto econômicos, além de garantir que o emprego dos RCD atenda a todas as normas vigentes. Com isso, reafirmou-se o compromisso com a preservação ambiental, pois a reciclagem desse tipo de entulho, além de ajudar a removê-lo da paisagem urbana, ainda gera diferenciais consideráveis em termos de economia de energia e de recursos naturais não-renováveis que seriam utilizados como matérias-primas, reduzindo a poluição do ar, da água, do solo, desafogando aterros sanitários, e visando atingir o desenvolvimento sustentável.Recycling of construction and demolition refuses (CDR) is a has been practiced since ancient history, when cities that were destroyed by war and natural disasters were rebuilt from their own ruins. Today, it is used in large scale in many countries in Europe and in the USA. In Brazil, where the concern with the destination of this kind of refuses is much more recent, few cities have planned and executed CDR management to this day. The side effects of this situation are plainly visible: the refuses have been continually and irregularly deposed in unused areas, thoroughfares, riversides, creeks and even in environmental protection areas, causing the proliferation of health-affecting problems, flooding and many other damages to the environment. Therefore, this study has the main goal of proposing solutions that can lessen the environmental impact by using CDR as aggregate in the manufacturing of concrete blocks. The lab tests and the comparing of the results obtained with those measured with the conventional techniques prove the viability of reutilizing these refuses, both in environmental and economical terms, as well as assuring that the use of CDR follows all the current regulations. With this, the compromise with environmental preservation is reinforced, since the recycling this type of refuse, beside helping to remove it from the urban landscape, generates considerable gains in saving energy and the non-renewable natural resources that would be used as raw material, lessening air, water and soil pollution, releasing the burden on landfills, always aiming at achieving sustainable development.
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Tabouy, Timothée. "Impact de l’échantillonnage sur l’inférence de structures dans les réseaux : application aux réseaux d’échanges de graines et à l’écologie." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS289/document.
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Dans cette thèse nous nous intéressons à l’étude du modèle à bloc stochastique (SBM) en présence de données manquantes. Nous proposons une classification des données manquantes en deux catégories Missing At Random et Not Missing At Random pour les modèles à variables latentes suivant le modèle décrit par D. Rubin. De plus, nous nous sommes attachés à décrire plusieurs stratégies d’échantillonnages de réseau et leurs lois. L’inférence des modèles de SBM avec données manquantes est faite par l’intermédiaire d’une adaptation de l’algorithme EM : l’EM avec approximation variationnelle. L’identifiabilité de plusieurs des SBM avec données manquantes a pu être démontrée ainsi que la consistance et la normalité asymptotique des estimateurs du maximum de vraisemblance et des estimateurs avec approximation variationnelle dans le cas où chaque dyade (paire de nœuds) est échantillonnée indépendamment et avec même probabilité. Nous nous sommes aussi intéressés aux modèles de SBM avec covariables, à leurs inférence en présence de données manquantes et comment procéder quand les covariables ne sont pas disponibles pour conduire l’inférence. Finalement, toutes nos méthodes ont été implémenté dans un package R disponible sur le CRAN. Une documentation complète sur l’utilisation de ce package a été écrite en complémentIn this thesis we are interested in studying the stochastic block model (SBM) in the presence of missing data. We propose a classification of missing data into two categories Missing At Random and Not Missing At Random for latent variable models according to the model described by D. Rubin. In addition, we have focused on describing several network sampling strategies and their distributions. The inference of SBMs with missing data is made through an adaptation of the EM algorithm : the EM with variational approximation. The identifiability of several of the SBM models with missing data has been demonstrated as well as the consistency and asymptotic normality of the maximum likelihood estimators and variational approximation estimators in the case where each dyad (pair of nodes) is sampled independently and with equal probability. We also looked at SBMs with covariates, their inference in the presence of missing data and how to proceed when covariates are not available to conduct the inference. Finally, all our methods were implemented in an R package available on the CRAN. A complete documentation on the use of this package has been written in addition
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Toe, David. "Etude de l’influence des peuplements forestiers de type taillis sur la propagation des blocs rocheux." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAU023/document.
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L'objectif principal de ce travail de thèse est d'améliorer la prise en compte des peuplements de taillis dans les logiciels d'analyse trajectographique.Dans un premier temps, un modèle numérique permettant de créer des peuplements virtuels de taillis à l'échelle du versant a été développé et validé sur la base d'inventaires forestiers réalisés dans des taillis.Deux modèles numériques permettant de simuler des impacts de blocs sur des franc pieds et des cépées ont été également développés en utilisant la Méthode des Éléments Discrets (MED).Ces modèles ont été calibrés par des essais d'impact sur des tiges de hêtre.Ils permettent d'intégrer l'influence du houppier et du système racinaire, de modéliser explicitement le contact entre le bloc et les tiges impactées, et d'intégrer les non-linéarités matérielles (rupture des tiges, délaminage) se développant dans le tronc au cours de l'impact.Ces travaux ont conduit à la construction d'un modèle trajectographique MED permettant de simuler la propagation d'un bloc dans une forêt de taillis à l'échelle du versant. Finalement, le rôle protecteur de différents peuplements de taillis contre l'aléa de chute de bloc a été caractérisé à l'aide de ce modèleThis research work is dedicated to improve the integration of coppice stands in rockfall analyses.First, a model was built to create virtual coppice stands. This model was validated using field inventories in coppice stands.Two numerical models were developed to simulate impacts of blocks on single trees and coppice stools using the Discrete Elements Method (MED).These models were calibrated using laboratory impact tests on beech stems.They account for the influence of the root system and of the crown on the tree dynamic response, the explicit modeling of the contact between the block and the impacted stem and the non-linearity evolution into the trunk during impact.Finally, a DEM rockfall software was developed to model rockfall propagation in coppice stands.The protective role against rockfall hazard of different coppice stands was characterized with this model
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Dao, Melissa. "Impact of Dispersed Nanoparticles in Block Copolymer Soft Solids." Research Showcase @ CMU, 2016. http://repository.cmu.edu/dissertations/779.
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Block copolymer soft solids are emerging as a means to spatially organize and store nanoparticulate material. Soft solids are formed as a disordered triblock copolymer solution [PEOx-PPOy-PEOx] transitions to a lyotropic liquid crystal. For certain chain architectures, the crystal structure of the soft solid undergoes an order-order transition (OOT) from spherical micelles packed in a cubic crystal structure to close packed cylindrical micelles. The focus of this thesis is to determine the impact of processing conditions and formulation on the structural parameters, flow mechanism, and timescales of soft solids. We study the effect of structural history and applied flow fields on the soft solids while the formulation is varied by incorporating nanoparticles into the polymer matrix. In the cubic phase, we found that the ordering kinetics occur on the timescale of minutes to tens of minutes depending on the structural history and the presence of particles. Furthermore, ordering of the cubic phase through the OOT occurs epitaxially. Without nanoparticles, a short application of high amplitude oscillations will macroscopically align the cubic and cylindrical phases into a persistent near single crystal. Changing the formulation through the addition of nanoparticles makes it more difficult to align the micellar crystals by shear, decreases the persistence of the alignment, and can change the unit cell of the micelle structure. By varying the formulation and phase behavior of the polymer matrix, nanoparticles can access different types of flocculation behavior. Specifically, the particles will aggregate in both the liquid and soft solid, remain dispersed in both phases, or re-disperse upon formation of the soft solid. These findings provide additional design parameters to improve the templating of nanoparticles in the soft solid as well as highlight the feasibility of using the phase behavior of the polymer solution to control the flocculation behavior and aggregate size. Most importantly, the results in this work are crucial for effective processing of these composite systems and for development of future applications.
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Lima, Filho Marçal Rosas Florentino. "Avaliação do desempenho mecânico de protótipo executado com blocos EVA: estudo de impactos horizontais em alvenarias e suas interações com outros elementos da construção." Universidade Federal da Paraíba, 2008. http://tede.biblioteca.ufpb.br:8080/handle/tede/5452.
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The utilization of residues of the footwear s industry, especially E.V.A. residues(Ethilene Vinil Acetate) in the Civil Construction Industry has been the focus of the researches. It is known that such residues can be used as artificial aggregates instead of natural aggregates in the production of lightweight cement composites. The focus of this research is the mechanical conduct of EVA blocks (normal dimensions) isolated and applied in prisms and masonries. The EVA block was also evaluated in real scale in LABEME and compared with a soil-cement prototype and theoretical results. Tests of horizontal impacts and interactions between masonries and others elements of the building( abrupt shutting door tests and suspended pieces effects in walls) took place. Based on the results, the conclusion is that it is possible to propose blocks with 60% of EVA aggregate, substituting natural aggregates in volume, having a minimum resistance to compression over or equal 1,0 MPa (in Laboratory molding), that are confirmed compatible with the non-structural function. Thus, it s believed that the perspectives for the viability of the utilization of this residue in the manufacture of blocks for civil construction are very good. This will certainly contribute for a double reduction of negative impacts in the environment, as long as it offers an alternative destiny to such residues and a consummation reduction of natural resources (sand and hail), promoting the sustainable development for the activity of civil construction.
O aproveitamento de resíduos produzidos pela indústria de calçados (aparas da produção de solas e palmilhas obtidas a partir de mantas de E.V.A. - Etileno Acetato de Vinila) na construção civil tem sido meta de pesquisas recentes. Sabe-se que tais resíduos têm grande potencial para serem empregados como agregados artificiais sintéticos, em substituição aos agregados naturais, na elaboração de compósitos cimentícios leves. O foco desta pesquisa é o comportamento mecânico dos blocos EVA1 (dimensões convencionais) isoladamente e quando os mesmos são aplicados em prismas e alvenarias. Para o bloco EVA1 avaliou-se o desempenho de protótipo em escala real, construído no LABEME e se comparou aos resultados com o protótipo, também em escala real, executado com blocos solo-cimento e referenciais teóricos. Foram realizados nesse protótipo ensaios de impactos horizontais (corpo mole e corpo duro) nas alvenarias e ensaios de interações entre as alvenarias e outros elementos da construção (fechamentos bruscos das portas e efeito de peças suspensas na parede). Com base nos resultados obtidos, tendo em vista o atendimento aos critérios e requisitos de impactos, pode-se concluir que é possível propor blocos de vedação com 60% de agregado EVA, substituindo em volume os agregados naturais, tendo resistência à compressão mínima maior ou igual 1,0MPa (em moldagem no Laboratório), que são comprovadamente compatíveis com a função não estrutural. Assim, acredita-se que são boas as perspectivas para a viabilização do aproveitamento desses resíduos na confecção de blocos de vedação a serem aplicados nas edificações. Isso contribuirá seguramente para uma dupla redução de impactos negativos no meio ambiente, na medida em que oferece uma alternativa ao destino para tais resíduos e uma redução do consumo de recursos naturais (areia e pedrisco), favorecendo o desenvolvimento sustentável para a atividade da construção civil.
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Caplinger, Robert. "The Impact of Flexible Interdisciplinary Block Scheduling on Reading Achievement." Thesis, University of Oregon, 2013. http://hdl.handle.net/1794/13226.
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The purpose of this study was to examine whether the use of a middle school flexible interdisciplinary block schedule would increase eighth-grade students' reading scores, as measured by the Oregon Assessment of Knowledge and Skills (OAKS). A 90-minute middle school flexible interdisciplinary block schedule served as the independent variable and was evaluated to determine its impact on student reading achievement. Extant data from the OAKS was used to assess student learning. Extant data from two groups of students were examined. The treatment group had their eighth-grade language arts and social studies classes scheduled into 90-minute flexible interdisciplinary block periods, taught by the same teacher. The comparison group had their eighth-grade language arts and social studies classes scheduled into traditional 45-minute departmentalized periods, taught by two separate teachers. The overall amount of time allocated to language arts and social studies instruction within the academic year was the same for both groups. However, the way the time was flexed and utilized within the class periods differed between the two groups. Research Question 1 addressed the possible increase in mean OAKS reading scores over time. Research Question 2 addressed the possible differences in the mean OAKS Reading Achievement Standards cut scores over time. The results of the two-year treatment condition of a FIBS for language arts instruction did not result in statistically significant results, as measured by the OAKS. The results suggest that there may not be a significant achievement difference between schools that implement an interdisciplinary scheduled compared to schools that implement a traditional, departmental approach.
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Furet, Agathe. "Modélisations expérimentale et numérique d'ouvrages pare-blocs modulaires : Application à la technologie Bloc Armé®." Thesis, Université Grenoble Alpes, 2020. http://www.theses.fr/2020GRALI038.
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Cette thèse Cifre s’intéresse au comportement sous impact de structures de protection issues de la technologie Bloc Armé® proposée conjointement par Géolithe Innov et Géolithe. La structure est composée de blocs en béton liaisonnés par des armatures métalliques verticales et horizontales. L’innovation principale réside dans le système d’armatures qui assure un liaisonnement des blocs et confère à la structure une capacité à répartir les efforts et à dissiper de l’énergie.Des essais à échelle réelle permettent de caractériser la réponse dynamique de la structure selon deux types d’essais. Premièrement, la structure mise en œuvre horizontalement sur une couche support est soumise à des impacts à haute énergie (2000 kJ) par lâchers verticaux d’un impactant. Deuxièmement, des essais à énergie moindre (125 kJ) sont réalisés par impact horizontaux sur un mur vertical de dimensions limitées. Des modèles réduits de la structure, à l’échelle ¼, sont également impactés, au laboratoire. Cette campagne est l’occasion de tester de nombreuses configurations de mur dans des conditions d’impact variées. Ces campagnes expérimentales permettent d’illustrer les mécanismes par lesquels une telle structure articulée se déforme sous sollicitation dynamique localisée. Les différents modes de déplacement des murs et certains phénomènes dissipant l’énergie d’impact sont mis en évidence et quantifiés. Les nombreuses mesures faites lors des essais constituent une importante base de données expérimentales, pour accompagner le développement du modèle numérique.Un modèle numérique aux différences finies est proposé pour cette structure. Une approche réaliste est suivie pour la modélisation : chacun des éléments de la structure est modélisé explicitement. Un modèle simple est volontairement considéré pour le béton constitutif des blocs. Le modèle est calibré d’après des valeurs issues de la littérature et des mesures faites spécifiquement. La confrontation des résultats de simulations d’impact avec les résultats expérimentaux témoigne d’une bonne aptitude du modèle à reproduire le comportement dynamique global de la structure et à estimer son déplacement résiduel, en particulier. Le modèle permet de quantifier la dissipation d’énergie découlant de la plastification du béton des blocs et des frottements dans la structure. Le modèle est ensuite utilisé pour simuler la réponse de murs de géométries variées et sous impact à haute énergie. Les perspectives de ce travail sont de proposer un modèle robuste capable de simuler des impacts à énergie de l’ordre de 5 000 kJ sur des ouvrages dont la géométrie pourra être complexeThis Cifre thesis investigates the impact response of protective structures based on the Bloc Armé® technology, developed by Géolithe Innov and Géolithe. This structure is made of concrete blocks linked by vertical and horizontal metal reinforcements. The main innovation lies in the reinforcement system which ensures the bonding of the blocks and gives the structure an ability to distribute the forces and dissipate energy.Two types of real-scale experiments permit to characterize the dynamic response of the structure. Firstly, the structure laid horizontally on a support layer is subjected to high- energy impacts (2000 kJ) by freely dropping of a projectile. Secondly, lower energy impact tests (125 kJ) are carried out by horizontal impact on a vertical wall of limited dimensions. Reduced models of the structure, at ¼ scale, are also tested under impact in the laboratory. This campaign permits to test many walls of different configurations under various impact conditions. These experimental campaigns illustrate the deformation mechanisms under localized dynamic solicitation for this kind of articulated structure. The different displacement modes of vertical walls and several phenomena dissipating impact energy are highlighted and quantified. The numerous measurements made during the tests constitute an important experimental database, supporting the development of the numerical model.A numerical model, developed with the finite differences method, is proposed for this structure. A realistic approach is followed for the modeling: each element of the structure is modeled explicitly. A simple model is deliberately considered for the concrete constituting the blocks. The model is calibrated based on values from the literature and measurements made specifically. The comparison of impact simulations results with experimental ones attests of the ability of the model in reproducing the global dynamic behavior of the structure and in estimating its residual displacement, in particular. The model quantifies the energy dissipation resulting from plasticization of the concrete blocks and from friction in the structure.The model is then used to simulate the response of walls of various geometries and under high energy impact. The outlooks of this work are to propose a robust model able to simulate the structure response to impacts with energies up to 5,000 kJ, considering structures with complex geometries
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Lambert, Stéphane. "Comportement mécanique de géocellules - application aux constituants de merlons pare-blocs cellulaires." Phd thesis, Université Joseph Fourier (Grenoble), 2007. http://tel.archives-ouvertes.fr/tel-00225981.
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Cette thèse s'intéresse au comportement mécanique de géocellules constitutives de merlons pare-blocs. Ces ouvrages sont des digues placées sur la trajectoire potentielle des blocs rocheux et visant leur arrêt. Les géocellules sont des structures métriques associant enveloppe préfabriquée et matériau granulaire. Les cellules étudiées sont cubiques et constituées de grillage à maille hexagonale et de géotextile, et remplies de matériau granulaire grossier, de sable ou de mélange sable-pneus déchiquetés.
Le comportement de cellules individuelles a été étudié expérimentalement pour des chargements pseudo-statique et dynamique. Il apparaît que la réponse de la cellule à faible déformation, sous compression pseudo-statique, dépend principalement des caractéristiques du matériau de remplissage. Celles de l'enveloppe interviennent en grandes déformations. Sous impact, par une sphère de 250kg, la capacité d'une cellule à limiter les contraintes transmises à son support dépend des conditions aux limites de la cellule et, dans une moindre mesure, du matériau de remplissage. La configuration optimale est une cellule remplie du matériau granulaire grossier libre de se déformer latéralement.
Les modèles numériques de comportement mécanique des matériaux et des cellules, de type éléments discrets, ont été calés et validés grâce aux résultats de ces expérimentations.
Les résultats ont été extrapolés à l'échelle de l'ouvrage dans le but d'orienter les choix structurels en vue d'expérimentations sur ouvrage vraie grandeur.
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Huber, Veronika Emilie Charlotte. "Climate impact on phytoplankton blooms in shallow lakes." Phd thesis, Universität Potsdam, 2010. http://opus.kobv.de/ubp/volltexte/2010/4234/.
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Lake ecosystems across the globe have responded to climate warming of recent decades. However, correctly attributing observed changes to altered climatic conditions is complicated by multiple anthropogenic influences on lakes. This thesis contributes to a better understanding of climate impacts on freshwater phytoplankton, which forms the basis of the food chain and decisively influences water quality.
The analyses were, for the most part, based on a long-term data set of physical, chemical and biological variables of a shallow, polymictic lake in north-eastern Germany (Müggelsee), which was subject to a simultaneous change in climate and trophic state during the past three decades. Data analysis included constructing a dynamic simulation model, implementing a genetic algorithm to parameterize models, and applying statistical techniques of classification tree and time-series analysis.
Model results indicated that climatic factors and trophic state interactively determine the timing of the phytoplankton spring bloom (phenology) in shallow lakes. Under equally mild spring conditions, the phytoplankton spring bloom collapsed earlier under high than under low nutrient availability, due to a switch from a bottom-up driven to a top-down driven collapse. A novel approach to model phenology proved useful to assess the timings of population peaks in an artificially forced zooplankton-phytoplankton system. Mimicking climate warming by lengthening the growing period advanced algal blooms and consequently also peaks in zooplankton abundance.
Investigating the reasons for the contrasting development of cyanobacteria during two recent summer heat wave events revealed that anomalously hot weather did not always, as often hypothesized, promote cyanobacteria in the nutrient-rich lake studied. The seasonal timing and duration of heat waves determined whether critical thresholds of thermal stratification, decisive for cyanobacterial bloom formation, were crossed. In addition, the temporal patterns of heat wave events influenced the summer abundance of some zooplankton species, which as predators may serve as a buffer by suppressing phytoplankton bloom formation.
This thesis adds to the growing body of evidence that lake ecosystems have strongly responded to climatic changes of recent decades. It reaches beyond many previous studies of climate impacts on lakes by focusing on underlying mechanisms and explicitly considering multiple environmental changes.
Key findings show that climate impacts are more severe in nutrient-rich than in nutrient-poor lakes. Hence, to develop lake management plans for the future, limnologists need to seek a comprehensive, mechanistic understanding of overlapping effects of the multi-faceted human footprint on aquatic ecosystems.Weltweit haben Seeökosysteme auf den Klimawandel der letzten Jahrzehnte reagiert. Beobachtete Veränderungen eindeutig dem Klimawandel zuzuordnen, wird jedoch häufig dadurch erschwert, dass Seen gleichzeitig vielfachen anthropogenen Einflüssen ausgesetzt sind. Diese Arbeit trägt zu einem besseren Verständnis des Klimaeinflusses auf Algen bei, die am Anfang der Nahrungskette stehen und maßgeblich die Wasserqualität eines Sees beeinflussen können. Zum größten Teil stützt sich die Arbeit auf eine dreißigjährige Datenreihe eines unregelmäßig geschichteten Flachsees im Nordosten von Deutschland (Müggelsee), in dem sowohl steigende Wassertemperaturen als auch sinkende Nährstoffeinträge zu verzeichnen waren. Bei der Datenanalyse wurde ein neu erstelltes dynamisches Simulationsmodell, genetische Algorithmen zur Parametrisierung von Modellen, und statistische Methoden der Klassifizierung und Zeitreihenanalyse genutzt. Ergebnisse dieser Arbeit zeigen, dass nicht nur klimatische Faktoren sondern auch die Nährstoffverfügbarkeit im See den Zeitpunkt der Algenfrühjahrsblüte (Phänologie) beeinflussen. Durch eine Veränderung der Mechanismen, die zum Kollaps der Blüte führen, trat diese trotz ähnlich milder Winterbedingungen bei hoher Nährstoffverfügbarkeit früher auf als bei niedriger. Ein neuentwickelter Ansatz zur Modellierung von Phänologie erwies sich als geeignet, um vorherzusagen, wann Algen und ihre Räuber in einem künstlich periodisch angetriebenen Laborsystem ihre Populationshöhepunkte erreichten. Eine Verlängerung der Wachstumsperiode führte dazu, dass diese früher auftraten. Die Untersuchung, warum sich Blaualgen im betrachteten See während jüngster Hitzewellenereignisse überraschend unterschiedlich entwickelt hatten, ergab, dass ungewöhnlich warmes Wetter nicht wie häufig vermutet generell förderlich für ihre Entwicklung ist. Der Zeitpunkt und die Dauer der Hitzewellen waren entscheidend dafür, ob für Blaualgen kritische Schwellenwerte der thermischen Schichtung im See überschritten wurden. Zudem zeigte sich, dass saisonale Erwärmungsmuster einen bedeutenden Einfluss auf Räuber nahmen, die das Auftreten von Algenblüten verhindern können. Diese Arbeit reiht sich in eine wachsende Anzahl von Studien ein, die zeigen, dass Seeökosysteme bereits stark auf die Klimaveränderungen der letzen Jahrzehnte reagiert haben. Mit ihrem Fokus auf Mechanismen und der expliziten Berücksichtigung simultaner anthropogener Einflüsse geht diese Arbeit gleichzeitig über viele bisherige Studien hinaus, die sich auf reine Beobachtung und die Betrachtung klimatischer Faktoren beschränkten. Kernergebnisse deuten daraufhin, dass Klimafolgen in nährstoffreichen Seen stärker ausfallen als in nährstoffarmen Seen. Nur mit einem umfassenden, mechanistischen Verständnis des vielfältigen anthropogenen Einflusses wird eine hohe Wasserqualität in Seen auch in Zukunft aufrechtzuerhalten sein.
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Zhang, Feng. "Cyanobacterial blooms: causes, innovative monitoring and human health impact." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1405800137.
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Rogers, Kate Shannon. "Impact of Block Scheduling on Standardized Reading Test Scores among 8th graders /." Staten Island, N.Y. : [s.n.], 2006. http://library.wagner.edu/theses/education/2006/thesis_edu_2006_roger_impac.pdf.
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Thesis (M.S.) - Wagner College, Department of Education, 2006. Wagner College theses are protected by copyright. They may be viewed from this source for scholarly, non-commercial purposes only. Reproduction and/or distribution in any format are prohibited.
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Aarstad, Olav Andreas. "Alginate sequencing : Block distribution in alginates and its impact on macroscopic properties." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for bioteknologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-20246.
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Walker, Ian. "Synthesis of novel siloxane containing block copolymers for impact modification of polybutyleneterephthalate." Thesis, Sheffield Hallam University, 1991. http://shura.shu.ac.uk/20485/.
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The aim of this work was to synthesise poly(butyleneterephthalate) (PBT) poly(dimethylsiloxane) (PDMS) block copolymers, containing the hydrolytically stable Si-C linkage. A number of routes involving mutually reactive oligomers were studied. Once synthesised the effect of the copolymer as a toughening agent for the PBT matrix was investigated. Siloxane copolymer precursors were synthesised by an equilibration reaction. The relative molar mass (RMM) of the precursor was governed by the initial ratio of end blocker to cyclic species. The functionality of the precursor determined by the end blocker. alpha, to hydroxy PBT oligomeric precursors were chemically modified, if necessary, to form mutually reactive species. Initial block copolymer synthetic routes concentrated on chloroplatinic acid catalysed hydrosilations in solution. This involved alpha, to di (hydrosilane) PDMS and alpha, to divinyl functionalised PBT. The lack of a suitable common solvent together with competing side reactions limited the progress of this route. Melt hydrosilation reactions proved ineffective also, because of the thermal instability of the catalyst. Further block copolymer experiments involving mutually reactive oligomers were performed in the melt. The most promising of these was one of transesterification. This used alpha,o-hydroxypropyl PDMS (RMM 1000) and alpha,o-hydroxy PBT (RMM 2000) precursors. Analysis indicated successful reaction to form a copolymer of low RMM. A higher RMM copolymer was desirable, for improved mechanical properties, and a number of approaches to achieve this were followed. Problems of competing reactions and ineffective catalysis were encountered. However, a material with promising mechanical properties was formed when using a diisocyanate as a chain extender. A PBT-PDMS copolymer was blended by itself, and also together with high RMM PDMS, in the PBT matrix. The mechanical properties of the blends were studied and compared. An improvement in impact properties, as compared to PBT, was achieved when the copolymer was used as an emulsifying agent in a PBT-PDMS blend.
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Delhomme, Fabien. "Etude du comportement sous impact d'une structure pare-blocs en béton armé." Chambéry, 2005. http://www.theses.fr/2005CHAMS004.
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Cette thèse a pour objet l'étude du comportement d'un nouveau système de galerie de protection contre les chutes de blocs appelé Pare-blocs Structurellement Dissipant (PSD). L'innovation majeure, par rapport aux solutions classiques, est de dissiper l'énergie d'impact directement dans la dalle en béton armé ou dans des appuis fusibles, et non plus dans une couche de matériau amortissant. Les phénomènes dynamiques ayant lieu lors de l'impact d'un bloc sur la dalle sont analysés au moyen d'expérimentations sur une structure PSD à l'échelle î 1/3. Les efforts de percussion appliqués à la dalle, durant la phase de contact avec le bloc, sont estimés ainsi que les différents transferts et dissipations d'énergie. Les résultats ont permis de valider le principe de fonctionnement et de réparation des PSD et font apparaître que la dalle est endommagée par trois mécanismes majeurs: le poinçonnement, la mise en flexion et la déstructuration de surface de la zone impactée. Les principales grandeurs expérimentales sont retrouvées à l'aide de simulations numériques des essais avec un code éléments finis. Un modèle mécanique simplifié "masses ressorts amortisseur" est également développé dans le but de concevoir des méthodes de dimensionnement applicables en bureau d'études. Les perspectives de ce travail sont d'aboutir à l'établissement de recommandations sur la conception et la réalisation des pare-blocs structurellement dissipantThis thesis studies the behaviour of a new concept for a protection gallery under rock fall, called Structurally Dissipating Rock-shed (SDR). The main innovation, compared to conventional solutions, is to dissipate the impact energy directly into the reinforced concrete slab or into fuse supports, and no longer in a cushion layer. The dynamic phenomena, taking place during the impact of a block onto the slab, are analyzed by means of experiments on a 1/3 scale SDR structure. The percussion loads applied to the slab, during the contact phase with the block, are assessed as weIl as the various energy transfers and dissipations. The results allowed to validate the operating and repair principles of the SDR and revealed that the slab is damaged by three main mechanisms: the punching, the bending and the breaking clown at surface level of the impacted zone. The principal experimental values are found by numerical simulations of the tests with a finite elements tool. A simplified mechanical model "masses-springs-damping" is also developed with the aim of implementing design methods for engineering offices. The prospects for this work are to succeed in establishing design and construction recommendations for structurally dissipating rock-sheds
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Boukria, Zoheir. "Caractérisation des impacts sur une galerie "pare-blocs structurellement dissipant"." Chambéry, 2009. http://www.theses.fr/2009CHAMS044.
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Cette thèse a pour objectif de quantifier l'aléa rocheux de type chute de blocs sur une galerie pare-blocs et ainsi pouvoir intégrer cette structure dans un système de détection et d'alerte de l'activité d'un versant rocheux. Pour ce type de problème, les méthodes inverses peuvent permettre une caractérisation (identification et localisation) de l'effort subi par la structure. Ces méthodes sont largement utilisées pour des structures de type poutre et plaques sous charges dynamiques inconnues. Pour résoudre ce genre de problème, l'une des approches les plus utilisées est de créer les fonctions de transfert entre des points d'impact et de mesure sur la structure expérimentalement ou numériquement, de mesurer les réponses, et de trouver la force par déconvolution du signal. Il est connu que ce type de problème est « mal posé ». Afin d'obtenir une solution stable ayant un sens physique, il faut généralement avoir recours à la régularisation soit par filtrage du bruit, soit par des méthodes de régularisation classique, telle que celle de Tikhonov. Le problème de caractérisation des impacts sur une structure devient plus complexe lorsque la localisation du point d'impact est inconnu. Pour résoudre ce problème, on peut utiliser une approche basée sur la minimisation d'une fonctionnelle représentant l'erreur entre les réponses mesurées et estimées en plusieurs points formant un quadrillage sur la structure. Dans le cas d'une structure en situation réelle avec des conditions aux limites complexes, il est préférable d'opter pour une approche expérimentale. Une série d'essai sur des structures simples de type poutre et plaque permet de contrôler les paramètres influents sur la qualité de reconstruction de l'effort. Afin de recréer les caractéristiques de la structure et son comportement, une application de la démarche sur une dalle en béton armée s'avère la plus appropriée. En utilisant les fonctions de transfert obtenues expérimentalement et validées numériquement, la localisation des efforts et l'identification de leurs historiques devient possible. Cette étude ouvre les perspectives d'étendre l'application des méthodes inverses à la caractérisation des efforts de type souffle générés par une avalanche ou par une explosionThe aim of this thesis is to quantify the hazard of rock fall on a rock-shed structure, and thus able to integrate this structure into a system of detection and warning. For this type of problem, the inverse methods may allow a characterization (identification and location) of the effort sustained by the structure. These methods are widely used for structures like beams and plates under dynamic loads unknown. To resolve this problem, one of the most used approaches is to create transfer functions between impact point and measuring point on the structure experimentally or numerically, measure responses, and find the force history by deconvolution of the signal. It is known that this type of problem is "ill posed". To obtain a stable solution with physical sense, it must generally be used to stabilize either by filtering noise, or by conventional methods of regularization, such as that of Tikhonov. The problem of characterization of impacts on a structure becomes more complex when the impact location is unknown. To resolve this problem, we can use an approach based on the minimization of an objective function representing the error between measured and estimated responses at several points forming a grid on the structure. In the case of a real structure with complex boundary conditions, it is preferable to opt for an experimental approach. A series of tests on simple structures like beams and plates can control the parameters affecting the quality of the force location and identification. To recreate the characteristics of the structure and behavior, an application of the approach on reinforced concrete slab is most appropriate. By using transfer functions obtained experimentally and validated numerically, the location and identification of force history becomes possible. This study opens perspectives to extend the application of inverse methods to characterize the efforts of such breath generated by a flood or an explosion
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Letsatsi, Paseka C. "The impact of regional integration in Africa: the case of South Africa and Botswana." Thesis, Nelson Mandela Metropolitan University, 2012. http://hdl.handle.net/10948/d1010176.
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Regional integration can refer to the trade unification between different states by partial or full abolition of customs tariffs on trade taking place within the borders of each state. This is meant in turn to lead to lower prices for distributors and consumers (as no customs duties are paid within the integrated area) and the goal is to increase trade. (Economic integration,1950, p66) According to Mattli (1999, p.42), the analysis of the first problem takes the decision to adopt an integration treaty as a given, and is primarily concerned with identifying the condition under which the process of integration is likely to succeed or to fail. Implementation of an agreement by heads of states to tie the economies of their countries closer together entails a lengthy process of establishing common roles, regulations, and policies that are either based on specific treaty provisions or derived from general principles and objectives written into the integration agreement. Regional integration can be applied for varying forms of economic co-ordination or co-operation amongst different neighbouring states, there will however always be different political agendas in the process. If there is a treaty amongst member states, this treaty has to be enforced or it may result in the development of differences. “In order to address national priorities through regional action most member states had been allocated the responsibility of co-ordinating one or more sectors. This involved proposing sector policies, strategies and priorities, and processing projects for inclusion in the sectoral programme, monitoring progress and reporting to the council of Ministers”. (Department of International Relations & Co-operation, Republic of South Africa). Richard Baldwin, Daniel Cohen, Andre Sapir and Anthony Venables argue that, using the same basic model as Bond and Sypropoulos (1996a), they consider trigger strategies such that initially there is inter-bloc free trade supported by the threat of perpetual trade war if any party breaks the agreement. Regional integration can be understood as the process of providing common rules, regulation, and policies for a region. Regional integration is defined as a process that allows member states to have access to each other’s markets on a voluntary basis and at various degrees. Economic, political, social and cultural benefits are realised from this interaction. (Lee MC, 1999, p30) Regional integration can be seen as co-operation in a broader context but can also be an important framework, through programmes within each regional bloc. According to (Keet ,2005,p22) since the birth of democratic South Africa, regional co-operation is also seen – in addition to the broader African aims-to be an important framework, through programmes within the Southern African Development Community (SADC), within which to address the gross imbalances created both within and between the economies of the region. Regional integration has become a way of assisting the emerging economies to be able to use their proximity to align their economies with the core for economic development. According to (Hamdok, 1998, p34) the effective implementation of regional integration is founded on an enabling environment that promotes accountability, transparency and respect for the rule of law. Also a strong institutional framework at the regional and national levels is fundamental to streamline regional agreements into national policies. In addition, the establishment of effective transnational implementation tools provide opportunities to push reforms conducive to good governance at the regional level. A clear demonstration of this can be observed in effective? legal systems and the need for a regional framework and related judicial institutions to provide an improved regional environment for private development. Integration always provides space for member states to assist in the development of other member states and which have a common economic approach to development. This is done in order to ensure that there are incentives for all member states as compared to those who are outside the bloc. As evidenced in the case of Europe, economic integration helps create a homogenous space and, to some extent, equalises living conditions and if all other regional blocs follow this process the benefit becomes greater. These appear to be prerequisites for a dialogue on the harmonisation of political stands. Indeed, an economic space that is physically integrated; where goods and services move speedily and smoothly; where, besides, the mobility of factors (manpower, capital, energy and inputs) are not subjected to hindrances; where, finally, microeconomic policies are harmonised, is likely to offer equal opportunities to all. Such a high degree of economic integration is not sustainable without a policy dialogue on issues that, at first, may not fall squarely under the rubrics of economic field; peace and security, defense, diplomacy etc. (Blayo N, 1998, P.5) The process of regional co-operation within the Southern African Development Community (SADC) started in in 1980 through the formation of the Co-ordinating Conference which was later changed to SADC IN 1992. Even though it is clear that the South African government played a dominant role because of its apartheid policies, the basic condition was to start the process of integration and open the process of economic co-operation within the region. The Governments of the Republic of South Africa, the Republic of Botswana, the Kingdom of Lesotho and the Kingdom of Swaziland- being desirous of maintaining the free interchange of goods between their countries and of applying the same tariffs and trade regulations to goods imported from outside the common customs area as hereinafter defined; “Recognising that the Customs Agreement on 29 June 1910 as amended from time to time , requires modification to provide for the continuance of the customs union arrangements in the changed circumstances on a basis designed to ensure the continued economic development of the customs union area as a whole, and to ensure in particular that these arrangements encourage the development of the less advanced members of the customs union and the diversification of their economies, and afford to all parties equitable benefits arising from trade among themselves and other countries”.(Government Notice, R 3914,p1). Even though there’s an acknowledgement that under the difficult conditions during apartheid, there was a need for the region to develop a common approach towards development and sustainable growth in the Southern African region. All countries in the region had to co-operate for long term sustainable economic growth, peace and security. “In 1980, the Southern African Development Co-ordination Conference (SADCC) was established with the major objectives of decreasing economic dependence on the apartheid regime and fostering regional development. The strategy adopted for meeting these objectives was regional development and co-operation. In 1992 SADCC was reborn, as the Southern African Development Community (SADC). The member states decided the time had come to move the region towards the creation of one regional market”. (Lee MC, 1999, p1) “Through the establishment of the Southern African Customs Union (SACU) the Southern African region has managed under difficult conditions of economic inequalities to standardise the trade links amongst member states, although there is still more to be done in the region to achieve shared goals of development. The Southern African Customs Union (SACU) links the trade, regimes of Botswana, Lesotho, Namibia, South Africa and Swaziland.
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Long, Xingyu. "Understanding Common Scratch Programming Idioms and Their Impact on Project Remixing." Thesis, Virginia Tech, 2021. http://hdl.handle.net/10919/103475.
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As Scratch has become one of the most popular educational programming languages, understanding its common programming idioms can benefit both computing educators and learners. This understanding can fine-tune the curricular development to help learners master the fundamentals of writing idiomatic code in their programming pursuits. Unfortunately, the research community's understanding of what constitutes idiomatic Scratch code has been limited. To help bridge this knowledge gap, we systematically identified idioms as based on canonical source code, presented in widely available educational materials.
We implemented a tool that automatically detects these idioms to assess their prevalence within a large dataset of over 70K Scratch projects in different demographic and project categories. Since communal learning and the practice of remixing are one of the cornerstones of the Scratch programming community, we studied the relationship between common programming idioms and remixes.
Having analyzed the original projects and their remixes, we observed that different idioms may associate with dissimilar types of code changes. Code changes in remixes are desirable, as they require a meaningful programming effort that spurs the learning process. The ability to substantially change a project in its remixes hinges on the project's code being easy to understand and modify. Our findings suggest that the presence of certain common idioms can indeed positively impact the degree of code changes in remixes. Our findings can help form a foundation of what comprises common Scratch programming idioms, thus benefiting both introductory computing education and Scratch programming tools.Master of Science
With over 68 million users and growing, Scratch has become one of the most popular programming languages for introductory computing learners. As with learning any programming language, understanding common programming idioms used in the language's application domain is important for both computing educators and learners. Educators need this understanding in order to fine-tune their curricular development, while learners can leverage this knowledge to effectively master the fundamentals by writing idiomatic code. Unfortunately, our understanding of what constitutes idiomatic Scratch code thus far has been limited. To address this knowledge gap, we systematically identified idioms based on source code with good code quality, as presented in widely available educational materials. We implemented a tool that automatically detects these idioms to assess their prevalence within a large, diverse dataset of over 70K Scratch projects. Since communal learning and the practice of remixing are one of the cornerstones of the Scratch programming community, we studied the relationship between common programming idioms and remixes. Having analyzed the original projects and their remixes, we found that different idioms may associate with dissimilar types of code changes. The ability to change a project in its remixes hinges on the project's code being easy to understand and modify. Our findings suggest that the presence of certain common idioms can positively impact the degree of code changes in remixes. Our findings can help form a foundation of what comprises common Scratch programming idioms, thus benefiting both introductory computing education and Scratch programming tools.
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Harkin, Linda Joan. "Block scheduling and its impact on graduation rates in Indiana public secondary schools." Virtual Press, 2001. http://liblink.bsu.edu/uhtbin/catkey/1203654.
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The purpose of this study was to examine the graduation rates of secondary schools in Indiana in 1989-90 and to compare those graduation rates to those of 199798, to see if those schools that adopted block scheduling had experienced a difference in graduation rates either positively or negatively. A comparison was also made of graduation rates between schools adopting block scheduling for at least three years and traditional schools during this same time period. Further examination was made to determine if any specific type of block schedule had improved graduation rates. The size school was also a consideration as to the affect of block scheduling on graduation rates. The study also sought to determine if block scheduling had an impact on attendance rates, discipline incidents, pupil teacher ratio, or full time teacher equivalency, all factors aligned to reasons why students drop out of school.The population for this study consisted of 251 Indiana public secondary schools, 203 schools which maintained a traditional schedule and 48 schools identified by the Indiana Department of Education to have adopted block scheduling prior to or including 1995-96, 1996-97, 1997-98. Nine research questions accompanied by Null Hypotheses for each were determined and tested. All data collection were from the Indiana Department of Education through reports compiled and generated from information submitted annually by all public schools in Indiana.Department of Educational Leadership
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Montgomery, Paul Edward. "The Impact of 4 X 4 Block Scheduling at an Urban High School." UNF Digital Commons, 2002. http://digitalcommons.unf.edu/etd/364.
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The primary purpose of this study was to examine whether attendance, academic achievement, school climate, student stress, and teacher burnout improved in an inner city, predominantly African American high school after the implementation of a 4 x 4 block schedule. Data concerning student academic achievement and absenteeism in 14 classrooms were gathered from the school's Annual Scholastic Reports. Data concerning the instructional practices of eight teachers were gathered through the teacher version of the Instructional Practices Survey and compared to a student version of the Instructional Practices Survey to determine whether student perception of instructional practices coincided with the teachers' perceptions. Classroom climate was examined by administering the Classroom Environment Survey to seven teachers and 130 of their students. Student stress levels were examined from the results of the School Situation Survey returned by 106 students. The Maslach Burnout Inventory was used to gather data concerning the burnout levels of 13 teachers. This study found that increases in grade point average and decreases in absenteeism were not achieved after three years of block scheduling. Instructional practices of the teachers involved in this study did not change significantly. School climate, student stress levels, and teacher burnout were found to be in the average range.
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Greuel, Jeff. "Impacts of block scheduling on technology education at Little Chute High School." Online version, 1998. http://www.uwstout.edu/lib/thesis/1998/1998greuelj.pdf.
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Ngamprasertwong, Pornswan. "Impact of Maternal Hypotension during Fetoscopic Surgery on Fetal Survival." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1335462758.
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Wong, Mei-fung Connie. "The impact of lump sum grant funding policy on the human resources management of non-government organizations in Hong Kong." Hong Kong : University of Hong Kong, 2002. http://sunzi.lib.hku.hk/hkuto/record.jsp?B25139745.
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Villanueva, Nilda Doris Montes. "Impacto dos contrastes de interesse no delineamento de um experimento em blocos." [s.n.], 1993. http://repositorio.unicamp.br/jspui/handle/REPOSIP/306728.
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Orientador: Armando Mario InfanteDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Ciencia da Computação
Made available in DSpace on 2018-07-18T20:28:19Z (GMT). No. of bitstreams: 1 Villanueva_NildaDorisMontes_M.pdf: 3766070 bytes, checksum: c0139a82d72c807f36bb4041399ac995 (MD5) Previous issue date: 1993
Resumo: Neste trabalho são exploradas as idéias de Pearce (1976, 1982), e Pearce et ai. (1974) sobre o planejamento estatístico de experimentos. O processo de construção de delineamentos em blocos foi especialmente estudado, procurando obter esquemas experimentais que possam responder com máximo detalhe às questões de interesse do pesquisador. Assim, o trabalho é orientado basicamente ao estudo dos contrastes de interesse, porquanto eles encontram-se diretamente relacionados com os objetivos do experimento. Contrastes naturais e básicos são estudados primeiro. Eles são estimados independentemente e com replicações efetivas e/ou fatores de eficiência facilmente determináveis. Ambos indicam possíveis partições da soma de quadrados dos tratamentos, fornecendo informação valiosa para a análise da variância dos resultados experimentais. A eficiência da maior parte dos delineamentos não ortogonais propostos por Pearce (1963), é explicitamente calculada através da estrutura espectral da matriz de informação correspondente a cada plano; os resultados obtidos são compilados numa tabela. A seguir, é explorado um teorema devido ,a Gupta (1988), que estabelece a relação entre a estrutura de dispersão de um conjunto de contrastes estimados e a matriz de informação do delineamento. Esse resultado permite encontrar planos experimentais compatíveis com especificações para a estimação dos contrastes de interesse. As conseqüências e limitações desse resultado são examinadas para diferentes estruturas de dispersão da matriz dos contraste1>, em particular no caso dos experimentos que visam à comparação de diversos tratamentos com um controle. Também são apresentadas diversas situações experimentais hipotéticas baseadas em uma ilustração devida a Pearce (1963). Finaln1.ente é estudaçla a A-otimalidade dos delineamentos de tipo S para a estimação de contrastes suplementares, estendendo os resultados de Gupta (1989) para o caso dos delineamentos não binário~. A utilidade da teoria apresentada para a construção de delineamentos é ilustrada mediante diversos exemplos, realizando os cálculos das quantidades relevantes mediante os pacotes estatísticos SAS e SOC.
Abstract: Pearce's conceptions on statistical planning of experiments are explored in this work. The construction process of block designs was especially considered, in order to obtain experimental designs that depend upon the experimenter's needs. This way, the work is oriented basically to the study of contrasts of chief interest, because they are directly related with the objectives of the experimento Firstly, are studied the natural and basic contrasts. They are estimated independently and with effective replications and/or efficiency factors that are readily determined. Both indicate possible partitions of the treatment sum of squares and aid of the appropriate analysis of variance. The efficiency of most non-orthogonal designs proposed by Pearce (1963) is explicitly calculated using the spectral decomposition of the associated information matrix. From these studies were contructed a new table for the compilation of the results obtained. Next, is explored Gupta's theorem, which gives the relationship between the set of contrasts estimated with specified variances and covarianices and the information matrix of the design. This result allows us to find experimental designs compatible with the experimenter's specifications for the precision of estimation of contrasts of interest. Consequences and limitations of these results are examined for different struct ures of the variance-covariance matrix associated with the contrasts, especially for experiments for the comparison of test treatments with a control. Hypothetical experimental cases based on Pearce's example (1963) are shown also. Finally, it is studied the A-optimality of type S designs for the estimation of supplemented contrasts, extending Gupta's results (1989) for non-binary designs. The usefulness of the theory presented in the construction of designs is illustrated in severaI examples, using the statistical packages SAS and SOC for calculation of the relevant quantities.
Mestrado
Mestre em Estatística
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Boussabah, Laith. "Impact of engineering modelling assumptions on assessing the seismic performance of Montgomery Block building." Thesis, University of Ottawa (Canada), 1993. http://hdl.handle.net/10393/6587.
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This study focuses on the Montgomery Block building, built in 1853 and which survived the 1906 San Francisco earthquake of magnitude 8.3 despite being roughly 15 km from the ruptured San Andreas fault (Freeman 1932). After a review of the existing literature on the seismic performance of unreinforced masonry structures, a summary of the lessons to be learned and an identification of the areas that require further research is presented. Then, an assessment of the range of predicted seismic capacities as estimated from traditional and conservative methods to the most liberal ones for the selected Montgomery building is conducted. Finally, a comparison of these capacities is performed to illustrate the impact of structural engineering modelling decisions on the predicted seismic performance of URM buildings. From this study, it is clear that depending on the structural model selected by the engineer, considerable differences of nearly an order of magnitude in some cases may exist in the seismic performance assessments of URM buildings.
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Stein, Jasmin. "Toughening of highly crosslinked epoxy resin systems." Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/toughening-of-highly-crosslinked-epoxy-resin-systems(de1605b9-d14d-43f1-83a1-dc13a7530179).html.
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Highly crosslinked epoxy resin systems are essential in aerospace applications due to the high operating temperatures. Although highly crosslinked epoxy resins have the required glass transition temperature (Tg) for the application, they are inherently brittle and matrix toughness is improved by incorporation of a second phase. Previous studies have focused mostly on toughening of lightly crosslinked epoxy systems, whereas this study investigates toughening of a highly crosslinked epoxy resin system using thermoplastic toughners poly(ether sulfone) (PES) and a poly(methyl methacrylate)-b- poly(butyl acrylate)-b-poly(methyl methacrylate) (MAM) block copolymer (BCP).
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Judikis-Preller, Juan C. "The impact of block scheduling on students and teachers in a high school : a description." Virtual Press, 1999. http://liblink.bsu.edu/uhtbin/catkey/1141214.
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The general purpose of this study completed in 1999 was to create an accurate, documented description of the experiences of nine students, three faculty members and two administrators in higher education in Chile during the military government 1973 - 1990.A qualitative approach was selected as the most appropriate methodology to' complete the study. A variety of methods and data collection strategies were used. The major data collection strategies were interviews and reviewing of primary and secondary written sources. The interviews were used to collect evidence concerning interviewees' experiences, as well as their attitudes, and perceptions regarding the events that occurred in higher education during the rule of the military government 1973 - 1990.The researcher decided to use a judgment sample of interviewees from the population based on their knowledge about the topic and their willingness to share their knowledge and experiences. Geographical representation, position within the institutions, kind of institution represented, and gender were major the considerations at the moment of selecting the sample too.Thanks to the U.S.A. Freedom of Information Act, which established an effective statutory right to access by any person or organization to federal government information, the researcher found official information that allowed for triangulation of evidence.The findings showed that the changes the military government implemented through their modernization of the educational system did not follow the historical trend of educational development in Chile. Furthermore, under the military government, policymaking in higher education was circumscribed to autocratic arenas, which usually coincided with government policy. Education was utilized to serve the purpose of the government. The educational system 1973 - 1990 failed to serve those with special needs. Free-market policies profoundly transformed education from a right available to all, to a commodity available in varying quantity and quality according to purchasing power of individuals.The impact of military government on higher education during the military rule was notorious and huge. Even though they were destructive in some aspects the military government did good things for the educational system. The issue in discussion is the price that was paid.Department of Educational Leadership
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Schott, Patrick W. Huffman Jane Bumpers. "From block to traditional schedule the impact on academic achievement, attendance rates, and dropout rates /." [Denton, Tex.] : University of North Texas, 2008. http://digital.library.unt.edu/permalink/meta-dc-9128.
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Schott, Patrick W. "From Block to Traditional Schedule: The Impact on Academic Achievement, Attendance Rates, and Dropout Rates." Thesis, University of North Texas, 2008. https://digital.library.unt.edu/ark:/67531/metadc9128/.
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The purpose of this study was to examine the impact of school schedule on student achievement and attendance of ninth and tenth grade students in metropolitan area Texas high schools (n = 22) and campus dropout rates. High schools that were analyzed in this study made a transition from A/B block scheduling in the 2003-04 school year to a traditional school schedule in the 2004-05 school year. Academic achievement, attendance rates and dropout rates were gathered through the archived files of the Texas Agency through the Academic Indicator of Excellence System (AEIS). Academic achievement was measured by the Texas Assessment of Knowledge and Skills (TAKS) Reading/Language Arts and Mathematics standardized tests. This study compared the mean scores of ninth grader student achievement, attendance, and dropout rates from the 2003-04 school year to the mean scores of the tenth graders from the same schools from the 2004-05 school year, after the schools converted from an A/B block schedule to a traditional class schedule. Each independent variable was divided into four subgroups; campus mean results, minority student results, limited English proficient (LEP) student results, and low-socioeconomic student results. Students under the A/B block scored significantly higher in reading achievement than when they were instructed the following year under a traditional schedule. Paired sample t-tests were conducted to analyze the data for each subgroup, and showed there was a statistically significance in reading / language arts student achievement scores for all subgroups. Statistical significance was determined with a ninety five percent confidence level (p < 0.05). Statistical analysis revealed varied results in mean scores for math academic achievement and attendance rates, but no statistical significant difference. Comparison of data showed a slight increase in mean scores for dropout rates in traditional schedule, however the results were not significant.
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Lorentz, Julien. "Etude de la capacité de dissipation sous impact d'une structure sandwich de protection contre les chutes de blocs rocheux." Phd thesis, Université Joseph Fourier (Grenoble), 2007. http://tel.archives-ouvertes.fr/tel-00143778.
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Cette thèse aborde le domaine de la protection passive contre les chutes de blocs rocheux. L'objectif est d'étudier un ouvrage composite dissipatif de protection : l'ouvrage sandwich. Il est composé d'une dalle en béton armé qui a pour rôle de répartir l'effort d'impact sur une deuxième couche composée de grave insérée dans des chaussettes de géotextile extensible contenues dans des colonnes de pneus de voitures usagés. Une campagne expérimentale de lâchers de blocs à l'échelle de l'ouvrage est réalisée dans le but de mesurer les efforts transmis par l'ouvrage pour des énergies cinétiques allant jusqu'à 90 kJ. L'ouvrage sandwich est bien adapté pour des énergies de 50 à 100 kJ. Pour des énergies supérieures, le double sandwich (superposition de 2 sandwichs simples) paraît mieux adapté pour diminuer l'intensité de la force transmise en améliorant l'effet de dissipation par une meilleure répartition de la charge d'impact. En parallèle, des simulations numériques grâce à la méthode des éléments discrets, et plus particulièrement le code SDEC, sont menées. Une procédure de calage des paramètres locaux est proposée pour simuler le comportement de l'ouvrage sandwich sous impact. Les paramètres élastiques et plastiques sont calés à partir d'essais quasi-statiques triaxiaux ou de compression simple. De plus, une loi de transfert de moment est ajoutée pour augmenter le frottement entre les grains ou pour modéliser la flexion de la dalle en béton armé ce qui permet de représenter le comportement de l'ouvrage pour une gamme d'énergie allant jusqu'à 45 kJ.
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Vinhal, Laís David. "Estudo de indicadores ambientais de blocos cerâmicos com base em avaliação do ciclo de vida, considerando o contexto brasileiro." Universidade Federal de São Carlos, 2016. https://repositorio.ufscar.br/handle/ufscar/8703.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
The construction sector is one of the sectors that most require natural resources and generate waste throughout the production chain. In this sense, given the need to preserve the environment and natural resources for future generations, the industry needs to improve the environmental performance of its operations chain. In order to achieve effective improvements by the actions developed by the sector, these actions need to be based on information about the environmental performance that are objective and verifiable. One of the methods that allow the collection of environmental information is Life Cycle Assessment (LCA), which is one of the main tools of environmental impact assessment for the lifecycle of products and systems. The LCA allows to evaluate the impacts of raw material extraction, manufacturing process, use and disposalt. In this context, a study of the manufacturing process of structural ceramic blocks (cradle to factory gate) was conducted, aiming to analyze its main impacts and processes that contribute most to these environmental impacts. To conduct this study data collection was performed in two plants located in the State of São Paulo. Based on data collected locally and on the international database Ecoinvent®, the life cycle inventory (LCI) was drawn up with the necessary adaptations to represent the local context. Life cycle impact assessment (LCIA) was carried out using the following methods: CML 2002, Edip 97, USEtox and IPCC 2013. Based on the LCIA results, it was possible to identify the processes that contributed to each of the impacy categories analyzed, with the electricity being the process that most contributed to all categories. But the fuel used in the burning of the blocks, in turn, did not generate significant environmental impacts due to factories studied using biomass. Therefore, this study allowed to evaluate the magnitude and importance of the environmental impacts generated by the manufacture of ceramic bricks and also to characterize the environmental performance of ceramic bricks based on LCA.
A construção civil é um dos setores que mais consome recursos naturais e gera resíduos na sua cadeia de produção. Neste sentido, diante da necessidade de preservar o meio ambiente e os recursos naturais para as futuras gerações, é fundamental que o setor melhore o desempenho ambiental de suas operações. Para que as ações desenvolvidas pelo setor resultem em melhorias efetivas, é necessário que elas sejam subsidiadas por informações sobre o desempenho ambiental, que sejam objetivas e verificáveis. Um dos métodos que permite a compilação de informações ambientais é a Avaliação de Ciclo de Vida (ACV), que se apresenta como um dos principais instrumentos de avaliação dos impactos ambientais gerados durante o ciclo de vida de produtos e sistemas. A ACV permite avaliar os impactos desde a extração de recursos naturais, processamento de matéria-prima, manufatura até o uso e descarte dos mesmos. Neste contexto, foi realizado um estudo do processo de fabricação de blocos cerâmicos estruturais (do berço ao portão da fábrica) com o intuito de averiguar seus principais impactos ambientais e os processos que mais contribuem para estes impactos. Para realizar este estudo, foi feita a coleta de dados em duas fábricas localizadas no Estado de São Paulo. Com base nos dados coletados in-loco e na base de dados internacional Ecoinvent®, o inventário do ciclo de vida (ICV) foi elaborado com as devidas adaptações para que representasse o contexto local. A partir do ICV, foi realizada a avaliação dos impactos do ciclo de vida (AICV) por meio dos métodos CML 2002, EDIP 97, USEtox e IPCC 2013. Com base nos resultados da AICV, foram identificados os processos que mais contribuíram para cada uma das categorias de impacto analisadas, sendo a eletricidade o processo que colaborou de forma mais significativa para todas as categorias. Já o combustível utilizado na queima dos blocos, por sua vez, não gerou impactos ambientais significativos, devido às fábricas estudadas utilizarem biomassa. Portanto, o presente estudo permitiu avaliar a magnitude e significância dos impactos ambientais gerados pela fabricação de blocos cerâmicos, bem como caracterizar o desempenho ambiental de blocos cerâmicos com base em ACV.
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Abebe, Opeyemi Temitope. "Regional trade agreements and its impact on the multilateral trading system: eroding the preferences of developing countries?" Thesis, University of the Western Cape, 2005. http://etd.uwc.ac.za/index.php?module=etd&.
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The purpose of this paper was to examine the impact that the proliferation of regional trade agreements have had on the Multilateral Trading System and whether by allowing regional trade agreements under the World Trade Organization rules, the members of the World Trade Organization have not unwittingly weakened the multilateral trading system. It also examined the effect the proliferation of regional trade agreements have had on the special and deferential treatment for developing countries within the system.
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Wolf, David M. "Beyond Marginal Valuation: The Economic Impacts of Harmful Algal Blooms." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1529492086337544.
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Cong, Danni. "Cyanobacteria blooms: from impacts on the environment to management strategies." Kansas State University, 2015. http://hdl.handle.net/2097/18930.
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Master of ScienceDepartment of Biological & Agricultural Engineering
Philip L. Barnes
Bloom-forming cyanobacteria are harmful to both environment and public health because of the release of water soluble toxins. This report provides a broad overview of cyanobacteria and cyanotoxins and the current state of knowledge about the bloom control management. Cyanobacteria blooms usually flourish in warm, lentic, and eutrophic waters. Several environmental factors such as temperature, nutrients, light intensity, and turbulence can affect cyanobacterial growth and the formation of bloom. Cyanobacteria can synthesize multiple types of toxins, which cause human and animal toxications worldwide. Cyanobacterial blooms also cause detrimental effects on aquatic ecosystems, and the taste and odor problems in drinking water supplies. Due to the adverse effects, treatments that are used for removing both cyanobacterial cells and aqueous cyanotoxins should be carried out once cyanobacterial blooms occur in freshwaters. Strategies based on physical, chemical, and biological methods are carried out to remove the cyanobacteria and cyanotoxins. All of these strategies have both advantages and disadvantages: some physical treatment methods can remove cyanotoxins within the intact molecules, but the cost is usually high and further processing is needed; some chemical methods are cheap and can degrade the cyanotoxins, however, the toxicological characterization of the chemical and the by-products needs to be investigated; some biological treatments are more environmentally friendly, but the long reaction time and some other external factors also pose some problems that affect the efficiency of the treatments. The paper concludes that the key to success is to find a reasonable balance between those advantages and disadvantages, and the specific conditions of each unique aquatic ecosystem should be taken into consideration. As well, some suggestions are also proposed for the further development of more robust monitoring and management strategies.
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Lovera, Cabrera Luciana Sofia, and Catari Ouear Owen Quispe. "Propuesta de plan de mejora en la gestión de agua y energía para la mitigación de Impactos Ambientales en edificios multifamiliares existentes de cinco pisos basado en recomendaciones EDGE. Caso: Block 03 – Condominio Héroes de San Juan y Miraflores." Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2021. http://hdl.handle.net/10757/656884.
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Actualmente, el planeta está sufriendo cambios climáticos debido a los gases del efecto invernadero; dentro de estos el más importante es el CO2, consecuencia del impacto ambiental que generan las industrias, y las diferentes actividades cotidianas que realizan los habitantes. En el Perú durante los últimos años las emisiones de CO2 se han incrementado con mayor aceleración. Dentro de tal contexto, el sector de la construcción es de los que más contaminación genera debido a la diversidad de materiales que utiliza para la preparación de concreto, además de los agregados que se extrae de la naturaleza. Justamente para lidiar con la contaminación y con el déficit de viviendas, cada vez se construyen más edificios teniendo en cuenta el factor ambiental. Sin embargo, actualmente existen gran cantidad de edificios que generan toneladas de CO2. Por tal motivo, este estudio se centra en el desarrollo de un plan de mejora basado en recomendaciones EDGE; certificadora de edificios sostenibles en el mercado inmobiliario peruano en la gestión de agua y energía; para que los habitantes de edificios multifamiliares existentes gestionen el uso agua y energía de manera eficaz, que posteriormente se traduce en menor emisión de CO2. Se aplicó el plan de mejora a un edificio multifamiliar de cinco pisos perteneciente al condominio Héroes de San Juan y Miraflores, en el que se evidenció una reducción del 30.22% en el consumo de agua, 23.95% en el consumo de energía, y como consecuencia una reducción en la emisión de CO2 de un 24%.Currently, the planet is undergoing climatic changes due to greenhouse gases; within them, the most important is CO2. This is a consequence of the environmental impact generated by industries, and various daily activities carried out by inhabitants. Precisely, something similar happens in Peru, in recent years CO2 emissions have increased with greater acceleration. Within this context, construction sector is one of those that generates most pollution due to the diversity of materials it uses for the preparation of concrete, including cement, a very polluting input, in addition to the aggregates that are extracted from nature. Just to deal with pollution and housing deficits, more and more buildings are being built taking into account the environmental factor. However, there are currently a large number of buildings that generate tons of CO2. For this reason, this study focuses on the development of an improvement plan based on EDGE recommendations; certifier of sustainable buildings in the Peruvian real estate market in water and energy management; so that residents of existing multi-family buildings manage water and energy use effectively, which subsequently translates into lower CO2 emissions. The improvement plan was applied to a five-story multifamily building belonging to the Héroes de San Juan y Miraflores condominium, in which a reduction of 30.22% in water consumption, 23.95% in energy consumption, and as a consequence a reduction in CO2 emissions of 24%.
Tesis
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Tang, Xuhai. "Impulse-based discrete element modelling of rock impact and fragmentation, with applications to block cave mining." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/24433.
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Impulse-based methods efficiently and accurately model high-frequency collisions of complex shapes based on the enforcement of non-penetrating constraints. It does not rely on penalty parameters nor requires the computation of penetration between bodies. This work presents a novel necessary condition for energy conservation in impulse-based methods. In previous versions of the impulse methods, such as sequential and simultaneous impulse methods, the relative velocity at the contact points after collision is directly derived from the relative velocity before collision, in a purely simultaneous or sequential manner. This work presents a novel energy tracking method (ETM), in which the relative velocities are iteratively but gradually adjusted, simultaneously modelling their interaction at each iteration. ETM ensures the energy conservation while capturing the propagation of forces during collision. The ETM is applied to model the dynamics of fragment collision in the context of fragmentation. Two approaches of fragmentation are proposed: a finite-discrete element approach, and a low cost, fragmentation pattern-based approach. The first approach models the growth of fractures using the finite element method (FEM) and advanced re-meshing technology. This finite-discrete element approach suffers from the drawback of massive computational cost. The low-cost, fragmentation pattern-based approach separate colliding bodies directly. The fragmentation pattern is generated using Weibull distribution equations, the patterns and size distributions computed using full finite/discrete element simulations and experimental results. This work investigates the influence of fragmentation on the frequency of hang-up events and on the gravity flow of rock fragments within a block caving system. Numerical results indicate that models that do not consider fragmentation tend to overestimate the frequency of hang-up accidents.
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Sombrio, Catarina Moraes de Oliveira. "ACV de painéis de blocos cerâmicos e concreto armado : um exercício de aplicação do manual do ILCD." reponame:Repositório Institucional da UnB, 2015. http://dx.doi.org/10.26512/2015.01.D.18503.
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Dissertação (mestrado)—Universidade de Brasília, Faculdade de Arquitetura e Urbanismo, 2015.Submitted by Albânia Cézar de Melo (albania@bce.unb.br) on 2015-05-15T15:16:23Z No. of bitstreams: 1 2015_CatarinaMoraesOliveiraSombrio.pdf: 2896569 bytes, checksum: 3bbff568cf37696c6d22fa6561ac5700 (MD5)
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A cadeia produtiva da indústria da construção (CPIC) é um dos maiores setores industriais no Brasil e no mundo, tendo grande representatividade econômica e gerando grandes impactos ambientais. Na busca de aumentar produtividade e reduzir os prejuízos ao meio ambiente os processos construtivos racionalizados vem sendo utilizados na produção de habitações de interesse social. Para a especificação de materiais com menor impacto ambiental, a avaliação do ciclo de vida (ACV) tem sido vista como uma ferramenta eficiente pois permite a avaliação do desempenho ambiental de materiais e produtos da CPIC, possibilitando a comparação entre materiais e o planejamento de construções com menores impactos ambientais. A ACV é normatizada pelas ISO 14040 e 14044 e detalhada por outras metodologias como a do ILCD, que foi adotada como padrão pelo PBACV. Neste estudo, aplica-se a ferramenta de ACV em um produto pré-fabricado da indústria da construção, que integra um processo construtivo racionalizado de edificações, aplicado na construção de habitações de interesse social no Distrito Federal, exercitando um método de aplicação da metodologia do Internacional Reference Life Cicle Data System (ILCD), analisando as dificuldades deste processo diante dos recursos e dados disponíveis. Os resultados do estudo demonstram a destoante participação do concreto nos impactos produzidos pela fabricação do produto, resultado que, considerando o grande uso do concreto na construção civil brasileira, aponta para a busca de sistemas alternativos como uma possível solução para minimizar o problema. O estudo contribui para a geração de dados nacionais referentes ao material estudado, ao mesmo tempo em que permite a estruturação dos conteúdos dos manuais do ILCD, por meio de questionários, que podem ser utilizados em outros estudos e na capacitação de ACV.
The supply chain of the construction industry (CPIC) is one of the largest industrial sectors in Brazil and in the world, with great economic representation and generating large environmental impacts. In seeking to increase productivity and reduce environmental damage the streamlined construction processes have been used in the production of social housing. For the specification of materials with lower environmental impact, life cycle assessment (LCA) has been seen as an effective tool that allows the assessment of the environmental performance of materials and products of CPIC, enabling the comparison of materials and the design of buildings with lower environmental impacts. LCA is standardized by the ISO 14040 and 14044 and detailed by other methods such as the ILCD, which was adopted as a standard by PBACV. This study applies the LCA tool in a prefabricated product of the construction industry, which includes a streamlined construction process of buildings, applied in construction of social housing in Federal District, Brazil, exercising one method of application of the methodology proposed by the International Reference Life Cycle Data System (ILCD), analyzing the difficulties of this process on the available resources and data. The study results demonstrate the great participation of the concrete in the impacts produced by the manufacture of the product, a result which, considering the large use of concrete in the Brazilian construction, points to the search for alternative systems as a possible solution to minimize the problem. The study contributes to the generation of national data for the studied material, while allowing the structuring of the contents of ILCD manuals, through questionnaires, which can be used in another studies and in the training of LCA.
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Plassiard, Jean-Patrick. "Modélisation par la méthode des éléments discrets d'impacts de blocs rocheux sur structures de protection type merlons." Phd thesis, Université Joseph Fourier (Grenoble), 2007. http://tel.archives-ouvertes.fr/tel-00290402.
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Les ouvrages type merlons, construits pour se prémunir contre les chutes de blocs rocheux, sont dimensionnés en pratique au moyen de méthodes empiriques. Afin d'optimiser la géométrie de ces constructions leur modélisation a été entreprise. La méthode aux éléments discrets est utilisée en raison des fortes restructurations du remblai constitutif pouvant intervenir durant un impact. A partir d'un état de l'art, les caractéristiques mécaniques du remblai sont évaluées. La calibration des paramètres quasi-statiques du matériau modèle est alors réalisée par simulations d'essais triaxiaux. Les paramètres gérant le comportement dynamique sont calibrés à leur tour par simulations d'impacts à énergies modérées. Le remblai modèle obtenu est validé par la modélisation d'essais d'impacts expérimentaux dont la gamme d'énergies correspond à celle rencontrée pour les merlons. Il est alors utilisé pour simuler des impacts sur merlons. Plusieurs tailles d'ouvrages sont étudiées, répondant chacune à des gammes d'énergies différentes. Une analyse paramétrique portant sur divers aspects du bloc et de l'ouvrage est réalisée. Elle permet de définir les variables principales gérant le phénomène d'impact. La variation couplée de ces dernières est réalisée afin d'établir leur influence sur la capacité du merlon à contenir le bloc.
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Davis, William R. "A study to determine the extent of use and impacts of block scheduling on technology education programs in middle size Wisconsin high schools." Online version, 1998. http://www.uwstout.edu/lib/thesis/1998/1998davisw.pdf.
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Zanden, Kjellen Peder. "Investigating the impact on marginal prices when using an increasing block tariff : An economic tool to reduce peak flowrates atwastewater treatment facilities." Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-39167.
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In wastewater management big variations in flowrates, caused by precipitation, leads to high peak loads forcing treatment facilities to maintain large over capacity. Wastewater management is a capital-intensive industry, meaning that new investments are costly and should therefore be avoided. But as peak load levels increase and stricter regulations are imposed it becomes increasingly hard to maintain sufficient reduction rates and facilities are likely to face new investments if the highest flowrates can’t be reduced. One way to reduce flowrates is to charge higher prices for the peak loads through an efficient tariff design. This thesis includes a literature review to define what constitutes an efficient tariff and then moves on to develop a model including marginal cost pricing and increasing block tariff design that examine how the marginal cost price is affected by constructing the tariff in different ways. The results show that the marginal price can be significantly increased by adapting this approach compared to a two part tariff with one fixed and one variable part which is commonly used by wastewater utilities today. The biggest deciding factor will be how the marginal block is defined.
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Wallström, Jenny. "Public’s behavioural responses to cyanobacterial blooms in Sweden : economic impact and demand for information." Thesis, Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:sh:diva-30824.
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Eutrophication caused by nutrient loads from human activities is considered as one of the most serious environmental threats to the Baltic Sea. Due to climate change, cyanobacterial blooms are expected to increase in the future. This could affect people’s utility of beach recreation negatively in countries surrounding the Baltic. Based on a web survey carried out in south-eastern Sweden, public’s reactions and attitudes to cyanobacterial blooms are analysed. Possible economic impact on Gotland of more widespread blooms are estimated, and public demand for better information is evaluated. The result shows that 30% of the respondents from south-eastern Sweden would consider cancelling their plans of travelling to Gotland with knowledge about forthcoming algal blooms around the island. Determinants of tourists’ tendency to cancel their travel arrangements are earlier negative experiences of algal blooms and concerns regarding their pets’ bathing. The annual local economic loss for Gotland’s tourism industry is estimated to between 15 and 221 million SEK. The median willingness to pay for a mobile application which provides one-day forecasts of algal blooms is 25 SEK on Gotland and 20 SEK in southeastern Sweden. Boat owners, people who visit beaches often and those who travel to Gotland frequently, are more likely to pay for the mobile application. People who think algal blooms are natural show less demand for information.
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Fernandes, Alexandra. "Impact of open channel blockers on the surface dynamics and organization of NMDA receptors." Thesis, Bordeaux, 2020. https://tel.archives-ouvertes.fr/tel-03177416.
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Les récepteurs du glutamate N-méthyl-D-aspartate (RNMDA) sont des acteurs clés de la transmission synaptique excitatrice, de la plasticité synaptique et des fonctions cérébrales supérieures telles que la formation de la mémoire et l'apprentissage. En conséquence, les dysfonctionnements NMDAR sont associés à des maladies neuropsychiatriques sévères et des investissements importants ont été réalisés pour développer des modulateurs de l'activité NMDAR en vue d’applications cliniques. Si certains antagonistes des RNMDA comme la kétamine (anesthésique, antidépresseur) ou la mémantine (prescrite dans le traitement de la maladie d'Alzheimer) se sont avérés d'une grande valeur médicale, leur utilisation clinique est souvent limitée par des effets indésirables graves (ex.: états psychotiques induits par la kétamine) et plusieurs questions concernant leur mode d'action - y compris pourquoi certains antagonistes présentent des propriétés psychoactives alors que d'autres non - restent sans réponse. De nombreuses données suggèrent qu'au-delà de leur fonction de canal, la signalisation RNMDA physiologique et pathologique peuvent impliquer des voies non canoniques indépendantes du flux ionique. En utilisant une combinaison d'approches d'épifluorescence, de FRET-FLIM, de biochimie et de microscopie de localisation de molécule unique, nous avons étudié l'impact des antagonistes RNMDA compétitifs (D-AP5, CPP) et non-compétitifs (MK-801, kétamine, mémantine) sur les propriétés, la redistribution et l’organisation nanométrique des RNMDA de surface et de leurs partenaires cytosoliques dans les neurones d'hippocampe. Nous avons constaté que si tous les antagonistes produisent une inhibition comparable de l'activité ionotrope des récepteurs, l'exposition aux bloqueurs psychomimétiques MK-801 et kétamine déclenche sélectivement des changements de conformation des RNMDA. Ces réarrangements conformationnels sont associés à une diminution de la diffusion de surface et à une augmentation du temps de résidence des récepteurs aux synapses, suggérant que le MK-801 et la kétamine accroissent l'ancrage synaptique des RNMDA. Bien que l'exposition aux drogues (1h) ne modifie pas l'abondance globale des récepteurs aux synapses, l'imagerie de super-résolution révèle des réorganisations nanométriques profondes et antagoniste-spécifiques des clusters de RNMDA synaptiques, une exposition à l'antagoniste compétitif D-AP5 entraînant une réduction de la taille et une augmentation de la densité des nanodomaines de récepteurs tandis que l'inhibition par les bloqueurs psychotomimétiques non compétitifs MK-801 et kétamine déclenche un élargissement des nanodomaines récepteurs, et que l'exposition à la mémantine provoque la fragmentation de ces nanodomaines. De plus, nous avons constaté que le MK-801 et la kétamine augmentent de manière sélective la mobilité de la protéine kinase Ca2+/calmoduline-dépendante (CaMKII) dans les épines dendritiques via un mode d'action qui repose sur l'interaction directe entre les deux partenaires, suggérant que les redistributions des récepteurs induites par les antagonistes pourraient avoir un impact sur la dynamique intracellulaire et l'organisation des partenaires de signalisation en aval des RNMDA. Dans l'ensemble, nos résultats montrent qu'en plus de l'inhibition des flux ioniques à travers les récepteurs, les antagonistes compétitifs et non compétitifs ont un impact différent sur la dynamique de surface et l'organisation sous-synaptique des NMDAR, et suggèrent que les bloqueurs psychoactifs MK-801 et kétamine peuvent agir sur la fonction des récepteurs via des réarrangements non-canoniques de l'organisation des complexes de signalisation RNMDAN-Methyl-D-Aspartate glutamate receptors (NMDAR) are key actors of excitatory synaptic transmission, synaptic plasticity and higher brain functions such as memory formation and learning. As a consequence, NMDAR dysfunctions are associated to pathological states and high investments have been made to develop modulators of NMDAR activity for clinical applications. While some NMDAR antagonists such as ketamine (anesthetic, antidepressant) or memantine (prescribed as a treatment for Alzheimer’s disease) have proven of great medical value, their clinical use is often limited by severe adverse effects (e.g. psychotic-like states induced by ketamine) and several questions regarding their action mode - including why some antagonists exhibit psychoactive properties when others do not - remain unanswered. Accumulating evidence suggests that beyond their channel function, physiological and pathological NMDAR signaling may involve non-canonical pathways independent from ion flux. Using a combination of epifluorescence, FRET-FLIM, biochemistry and single molecule localization microscopy approaches, we investigated the impact of competitive (D-AP5, CPP) and uncompetitive (MK-801, ketamine, memantine) NMDAR antagonists on the properties, redistribution and subsynaptic organization of surface NMDAR and their cytosolic partners in hippocampal neurons. We found that while all antagonists produce comparable inhibition of NMDAR ionotropic activity, exposure to the psychotomimetic blockers MK-801 and ketamine selectively triggers changes in the conformation of NMDAR. Interestingly, these conformational rearrangements were associated with a decreased surface diffusion and an increased residency time of receptors at synapses, suggesting MK-801 and ketamine binding possibly enhance NMDAR synaptic anchoring. Although drug exposure (1h) did not change the overall receptor abundance at excitatory synapses, super-resolution imaging revealed profound and antagonist-specific nanoscale reorganizations of synaptic NMDAR clusters, with exposure to the competitive antagonist D-AP5 causing a reduction in the size and an increase in the density of receptor nanodomains while inhibition by the uncompetitive psychotomimetic blockers MK-801 and ketamine triggered an enlargement of receptor nanodomains, and exposure to memantine prompted the fragmentation of these nanodomains. Moreover, we found that MK-801 and ketamine selectively enhanced the mobility of Ca2+/calmodulin-dependent protein kinase II (CaMKII) within dendritic spines through an action mode that relies on the direct interaction between both partners, suggesting that drug-induced receptor redistributions may impact the intracellular dynamics and organization of downstream signaling partners of NMDAR. Altogether, our results provide evidence that besides inhibition of ion fluxes through the receptors, competitive and uncompetitive antagonists have a different impact on NMDAR surface dynamics and subsynaptic organization, and suggest that the psychoactive blockers MK-801 and ketamine may act on receptor function through non-canonical rearrangements in the organization of NMDAR signaling complexes
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Richardson, James Kenneth. "The impact of block scheduling on student performance on the Virginia Standards of Learning End-of-Course assessments." W&M ScholarWorks, 2000. https://scholarworks.wm.edu/etd/1550154151.
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Cornejo, Castro Marco Antonio. "Impacto en la Productividad del Nivel de Traspaso en la Confiabilidad de un Programa de Producción." Tesis, Universidad de Chile, 2008. http://repositorio.uchile.cl/handle/2250/103165.
Full textAbstract:
Los métodos de explotación subterráneos Block/Panel Caving poseen componentes de
infraestructura de producción tales como puntos de extracción, cruzados de producción piques de
traspaso y cruzados de transporte. Estos están sujetos a ser interrumpidos debido a diversos
tipos de eventos geotécnicos tales como sobretamaños, colgaduras, desplomes, reparación de
carpetas de rodado, falla de martillos picadores, entre otros. Existe evidencia que la productividad
de la mina y sus componentes de infraestructura dependen del número de eventos a
experimentar en un periodo de tiempo. La productividad de la mina depende de la productividad
de cada componente, siendo los piques de traspaso fundamentales en definir esta productividad.
El objetivo del presente trabajo, es cuantificar el efecto del sistema de traspaso en la confiabilidad
de un programa de producción minero, en particular en la productividad de cruzados de
producción.
El estudio se centra en el análisis de la mina DOZ de la compañía PT Freeport Indonesia,
quienes cuentan con información histórica de producción e interferencias operacionales de los
piques de traspaso del año 2006. Con estos se construyen curvas de productividad y frecuencia
de eventos por pique, siendo las colgaduras el evento más frecuente (7 por mes) y los eventos
mecánicos casi constantes durante todo el periodo (2 por mes). La producción de la mina se
sostiene en los piques más maduros (80 – 130 Kt/mes) los que están relacionados con el cruzado
de transporte 2.
La modelación de la producción permite definir curvas de frecuencias de eventos (Curva U) las
que muestran la relación entre la frecuencia de ocurrencia de eventos y el tonelaje acumulado de
una componente y curvas de productividad (Curva de Producción Característica) la que describe
las toneladas/período de un componente de la infraestructura minera, en función del número de
eventos experimentados
Con las Curvas U y de producción características alimentan de modelos simulación de eventos
discretos en Arena software para cuantificar la influencia de las interferencias operacionales de
los piques en el cruzado de producción. En estas se aprecia que para una calle de producción,
las productividades disminuyen si el número de eventos en los piques es mayor (diferencias de
productividades de hasta 35 Kt para piques sin eventos y piques que fallan cada 7 Kt).
En resumen, se propone considerar en la elaboración del plan de producción las interferencias
operacionales ocurridas en los piques de traspaso, ya que como se demostró la influencia de
estas puede ser significativa a la hora de extraer lo que indica el plan.
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Qin, Qubin. "Impacts of Physical Transport on Estuarine Phytoplankton Dynamics and Harmful Algal Blooms." W&M ScholarWorks, 2019. https://scholarworks.wm.edu/etd/1550153910.
Full textAbstract:
The spatial and temporal variability of phytoplankton biomass in estuaries is determined by both local processes and transport processes. Local processes include biological processes (e.g., photosynthesis, respiration/excretion, and grazing) and settling, whereas transport processes include advective and diffusive transports. Transport processes have been demonstrated to regulate phytoplankton dynamics significantly by distributing both phytoplankton and other dissolved and particulate substances (e.g., nutrients, salts, sediments, and chromophoric dissolved organic matter). Yet, these transport properties lack a framework that unifies the pieced description of their various effects, and quantification of their importance under various environmental conditions. This dissertation highlights the role of horizontal transport processes on phytoplankton dynamics in estuaries, including the initiation of harmful algal blooms (HABs). in Chapter 2, the flushing effect of transport processes and its interaction with local processes are exclusively examined, and its relative importance on the variability of phytoplankton biomass is quantified and compared to that of the local processes over timescales from hours to years, using an introduced concept of transport rate that can be numerically computed. in Chapter 3, a simple yet inclusive mathematical model is developed to examine the temporal and spatial variabilities in phytoplankton biomass in response to the various effects of physical transport, under nutrient and light limiting conditions. For estuaries whose dominant nutrient loading is from river input, three basic patterns are revealed for the relationships between phytoplankton biomass and flushing time under various environmental conditions. in Chapters 4 and 5, the flushing effect of transport processes on the initiation of harmful algal blooms (HABs) in estuaries is investigated, which is then applied to examine the location and timing of the initiation of an annual Cochlodinium (recently renamed Margalefidinium) polykrikoides bloom in the lower James River. Theoretical analysis shows that the flushing is the key factor that affects HAB initiation in multiple interconnected systems, and a relatively long period of time (weeks) is required for a successful bloom. A HAB tends to be observed first in locations with relatively long residence time, such as tributaries or areas with large eddies. Multiple unconnected originating locations can co-exist within an estuary that highly depends on hydrodynamics and salinity. A numerical module for C. polykrikoides bloom is developed and built into a 3D numerical model - EFDC, which considers the competitive advantages of C. polykrikoides such as mixotrophic growth, swimming, grazing suppression, and resting cyst germination. Numerical model results show that the flushing effect determines the origins of C. polykrikoides blooms in the lower James River, and the sub-tributary of Lafayette River, which is characterized by relatively long residence time, is favorable for the first bloom to occur, regardless of the cyst distribution. A further investigation of various environmental conditions for the C. polykrikoides bloom reveals that temperature and physical transport control the interannual variability in the timing of its initiation, and individual perturbations by southerly wind, heavy rainfall, and spring tide can cause strong flushing capable of interrupting, or even terminating, initiation of a HAB event in the lower James River.
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Fortin, Samantha Grace. "Estuarine Microbiomes And Biogeochemistry: Impacts Of Spatiotemporal Variation, Algal Blooms, And Microplastics." W&M ScholarWorks, 2021. https://scholarworks.wm.edu/etd/1627407480.
Full textAbstract:
Estuaries are biogeochemical hotspots connecting terrestrial and coastal ecosystems. Anthropogenic disturbances, including increased nitrogen loading and plastic pollution, may have significant impacts on estuarine carbon and nitrogen cycling by altering microbiome structure and functions. The overarching goal of this dissertation was to examine how microbiomes and their associated biogeochemical processes are influenced by natural variation and anthropogenic disturbances in the York River Estuary (YRE). In chapter 2, spatial and temporal variation in benthic microbiomes and the rates of denitrification, anaerobic ammonium oxidation (anammox), and dissimilatory nitrate reduction to ammonium (DNRA) were examined to determine biotic and abiotic drivers of nitrogen removal and retention. In the YRE, nitrogen removal, largely in the form of denitrification, dominated at the head of the estuary while nitrogen retention through DNRA dominated at the mouth. Denitrification was linked to a large community of denitrifying organisms, sediment organic matter, nitrate/nitrite concentrations, salinity, and chlorophyll a, while DNRA was best predicted by the abundance of specific taxa, Desulfobacterales and Sphingobacteriales, as well as temperature and the concentration of ammonium. The impacts of the harmful algal blooms of Margalefidinium polykrikoides and Alexandrium monilatum that occur in the lower portion of the estuary were examined in Chapter 3. Blooms of both species altered the water column microbiome of the YRE. The M. polykrikoides bloom, with its higher concentration of dissolved organic carbon and close associations with heterotrophic bacteria, likely has a greater impact on the estuarine carbon cycle than the A. monilatum bloom. The A. monilatum bloom did not impact the overall prokaryotic community, but appeared to selectively enhance a small group of prokaryotes in the particle-associated fraction. Chapters 4 and 5 investigated plastic pollution in the YRE. A method was developed to isolate, quantify, and identify the polymer type of plastic particles in wastewater treatment plant effluents using Raman microspectroscopy (chapter 4); microplastic particles composed of polyethylene were found to be the most common. Microplastics composed of polyethylene, polyvinyl chloride, and polylactic acid were deployed to the YRE and the microbial biofilm communities growing on each type of plastic were examined over time to determine their taxonomic and functional profiles (chapter 5). All three microplastic types were found to contain potential hydrocarbon degrading bacteria, as well as nitrogen cycling bacteria capable of performing nitrification, denitrification, and DNRA. Overall, this dissertation investigated how microbially mediated nitrogen cycling processes can remove or retain fixed nitrogen, how algal blooms can change an estuary’s microbiome, and how the addition of microplastic pollution can provide new habitat for microbes that can perform nitrogen cycling and hydrocarbon degradation in the water column.
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Velásquez, Herrera Milenka Concepción. "Efectividad del advertising en blogs: impacto de la parcialidad del mensaje, expertise del comunicador e intención publicitaria." Tesis, Universidad de Chile, 2011. http://www.repositorio.uchile.cl/handle/2250/113682.
Full textAbstract:
Tesis para optar al grado de Magíster en MarketingNo disponible a texto completo
La publicidad en blogs es una estrategia que se ha difundido en los últimos años; su objetivo es lograr informar y persuadir a los consumidores a través de un medio de comunicación relativamente nuevo y que cuenta con una amplia base de seguidores. Para entender la efectividad de esta estrategia este estudio se enfoca en analizar el efecto de tres variables ejecucionales sobre la credibilidad de fuente y la intención conductual del consumidor. Las variables tratadas son: la parcialidad del mensaje (unilateral/bilateral), el expertise de comunicador (alto/bajo) y la intención publicitaria (explícita/implícita). La inclusión de la parcialidad del mensaje dentro del contexto de la publicidad en blogs es el principal aporte de la investigación, pues no existen investigaciones previas que incluyan esta variable y su influencia sobre la credibilidad de fuente e intención conductual. La investigación se realizo en base a un blog tecnológico, dado que es uno de los temas más tratados en este medio. Los resultados evidenciaron que los mensajes bilaterales obtienen mejores resultados en las dos variables independientes. La intención publicitaria implícita genera efectos positivos en la credibilidad de fuente e intención conductual. Un alto nivel de expertise genera mayor credibilidad y efectividad de la publicidad. Cuando las variables interactúan se observo que si se explicita la intención publicitaria los mensajes bilaterales son más efectivos y generan mayor credibilidad de fuente. La investigación evidenció también que un comunicador de bajo expetise genera mayor credibilidad y es más efectivo cuando se lo combina con un mensaje bilateral a pesar del desajuste presente entre este tipo de endorser y un producto de alto involucramiento (notebook).
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Viera, Quezada Eduardo Ignacio. "Impacto de Sistemas de Altas Velocidades de Extracción en la Planificación Minera para Block/Panel Caving." Tesis, Universidad de Chile, 2011. http://www.repositorio.uchile.cl/handle/2250/104013.
Full textAbstract:
No autorizada por el autor para ser publicada a texto completoLas actuales condiciones de operación de la minería por hundimiento producen bajas velocidades de extracción y costos operacionales que progresivamente han ido en aumento, lo cual impacta directamente en la rentabilidad de los proyectos. Los sistemas de altas velocidades de extracción (SAVE) surgen como una respuesta tecnológica de alta productividad, considerando equipos estacionarios de extracción y acarreo que funcionan en forma continua y simultánea. La planificación de los SAVE es diferente al sistema LHD tradicional, a causa de los disímiles montos de inversión que requieren y estructura de costo fijo y variable. El objetivo principal de éste trabajo es cuantificar el impacto económico que genera la implementación de un SAVE, para lo cual se considera el efecto que genera los SAVE en las variables que influyen en la planificación minera, principalmente en el método de explotación (Block/Panel Caving), estructura de costos, secuencias de explotación, alturas de columna y área activa. Las restricciones aplicadas al Panel Caving limitan la velocidad media de extracción del método, principalmente durante el proceso de propagación del quiebre (extracción del 30% de la columna mineralizada). Por el contrario un SAVE, aprovechando la simultaneidad de la extracción y aplicación del pre-acondicionamiento, puede ser explotado mediante un esquema de block caving, puede triplicar los rendimientos del área. La estructura de costos es completamente distinta al sistema LHD tradicional, siendo el costo fijo (preparación) el de mayor incidencia. El costo operacional se reduce considerablemente con respecto al sistema LHD tradicional (50%), lo cual genera un aumento de las alturas de columnas extraíbles debido a la disminución de las leyes de cierre. Finalmente se realiza una evaluación económica comparativa entre un SAVE y un sistema LHD tradicional, obteniendo un aumento de VAN del 18% que se debe principalmente a la reducción del gasto operacional y de preparación.