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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

The relationship between methane emissions and economic growth between High income and Low income countries

Björk, Zackarias, Ahlm, Nathanael January 2022 (has links)
The Intergovernmental Panel on Climate Change 2018 highlights the importance of short-lived greenhouse gasses to combat global warming. This study explores the relationship between Gross Domestic Product per capita and methane per capita. The relationship is explored in relation to the Environmental Kuznets Curve theory where the subjects to examination used are High Income Countries and Low Income Countries based on United Nation classifications in 2019. In total 47 countries are examined where 30 countries are High Income Countries and 17 are Low Income Countries. The relationships are examined for the time periods 1970 to 2017 through Fixed Effect Models. To improve accuracy additional control variables are added: Population in agriculture (% of total employment), balance of payments and forest areas. With the added control variables, the time frame used in Fixed Effect Models changes to 1991 to 2017. The different Fixed Effect Models provide inverted U-shaped relationships for Low Income Countries and uncertain results for High Income Countries according to the Environmental Kuznets Curve.
12

Feasting and Social Integration in the Formative Period: New Evidence from Cerro Blanco, Lower Nepeña Valley / Festines e integración social en el Periodo Formativo: nuevas evidencias de Cerro Blanco, valle bajo de Nepeña

Ikehara, Hugo, Shibata, Koichiro 10 April 2018 (has links)
This paper presents new evidence recovered from recent archaeological research at Cerro Blanco. These materials show that food and beverage consumption ceremonies were part of the variety of activities carried out at many Formative Period centers. The analysis of the data from the site allows us to discuss the social organization tied to feasting behavior and helps explain the interest in the acquisition of foreign items. / En este trabajo se presentan nuevas evidencias encontradas en recientes excavaciones del sitio de Cerro Blanco de Nepeña que sugieren que las ceremonias con consumo de comidas y bebidas fueron parte de las actividades realizadas en los centros del Periodo Formativo. Adicionalmente, el análisis del material encontrado permitió definir la organización social detrás de estas y proponer una hipótesis para explicar el interés de la población de este periodo en la obtención de objetos de otras regiones.
13

Analysis of the English language produced by a Swedish 4-year-old child in the light of the innatist perspective : A case study

Wistrand, Ida January 2021 (has links)
This is a case study that focuses on the oral proficiency in English manifested by the 4-year-old sonof the author. He speaks Swedish as his L1 like his both parents but has been exposed to Englishsince he was one year old from using a tablet. The child’s spoken production was recorded andtranscribed with a focus on the plural-forms and the genitive. An important field that this case studyis motivated by is how child language development may be connected to the concept of innatism,that language is based on innate principles (Lightbown & Spada, 2013:20) as it has been found that anumber of languages are acquired according to predictable patterns and processes (Moskowitz,1994:621-627) such as a the u-shaped learning process and over-generalization which has beenfound when investigating both L1 and L2 acquisition (Abrahamsson, 2013:663). The aim of thisstudy is to find possible similarities within the learning process: whether L2 acquisition follows thesame developmental patterns as in L1 acquisition by analyzing the recordings mainly targeting theplural and the genitive morphemes produced by a 4-year-old L2 speaker of English. Findings in thisresearch revealed that the child demonstrated a similar developmental pattern in the form of theu-shaped learning process (Abrahamsson, 2013:663).
14

MECANISMES DE REGULATION<br />DE L'HEMATOPOÏESE EMBRYONNAIRE<br />CHEZ LA DROSOPHILE

Bataillé, Laetitia 30 June 2006 (has links) (PDF)
L'hématopoïèse regroupe les phénomènes menant à la formation des composantes<br />cellulaires du sang. Au cours de ce processus, des cellules précurseurs vont proliférer et se<br />différencier dans les multiples types cellulaires spécialisés. Le développement du système<br />hématopoïétique de la Drosophile et des vertébrés présente de nombreuses similitudes aussi bien<br />au niveau fonctionnel et ontogénique qu'au niveau des gènes qui régulent la formation des<br />cellules sanguines. Chez la Drosophile, au stade embryonnaire, les précurseurs<br />hématopoïétiques, les prohémocytes, vont générer deux types de cellules sanguines, les<br />plasmatocytes et les cellules à cristaux. Nous avons entrepris de caractériser les mécanismes de<br />régulation de l'hématopoïèse embryonnaire chez la Drosophile.<br />Dans un premier temps, nous avons analysé la fonction et le mode d'action du facteur de<br />transcriptions de type GATA Serpent (Srp) au cours de ce processus. Nous avons mis en<br />évidence que le gène serpent code pour deux isoformes qui ont des activités différentielles au<br />cours de ce processus. D'autre part, nous avons montré que l'activité de Srp au cours de<br />l'hématopoïèse est modulée par recrutement de cofacteurs. Ainsi, nous avons montré que Srp est<br />capable de recruter U-Shaped, un cofacteur de type FOG (Friend Of GATA), mais aussi, de<br />former un complexe fonctionnel avec le facteur de transcription de type RUNX, Lozenge. La<br />caractérisation des isoformes de Srp et la mise en évidence de l'interaction de ce facteur GATA<br />avec différents partenaires a permis de mettre en évidence la versatilité des fonctions de srp au<br />cours de l'hématopoïèse.<br />Dans un second temps, nous avons entrepris de caractériser in vivo l'étape de ségrégation<br />des deux populations, plasmatocytes et cellules à cristaux. Nous avons mis en évidence que la<br />ségrégation de ces deux lignages à partir d'une population de prohémocytes bipotents est un<br />processus très dynamique, contrôlé par un mécanisme original en deux étapes. Cette régulation<br />qui fait intervenir les facteurs de transcription lignage-spécifiques Lozenge et Glial-Cell-<br />Missing (Gcm) et Gcm2, contrôle précocement la détermination des précurseurs et tardivement<br />le maintient de l'identité de ces cellules dans les phases de différenciation en cellules à cristaux<br />versus plasmatocytes. De manière intéressante, nous avons montré que la régulation de la<br />ségrégation, ne repose pas sur un antagonisme réciproque entre les facteurs de transcription<br />lignage-spécifiques. Ce mécanisme qui contrôle l'acquisition d'un destin cellulaire diffère donc<br />des processus de régulation de l'hématopoïèse mis en évidence chez les mammifères.
15

Nový pavilon SOU Písek / New pavilion SOU Písek

Troup, Tomáš January 2017 (has links)
Diploma thesis deals a project documentation of a new school pavilion SOU in the location Pisek because of the unsatisfactory existing school bulding, which is located at a small distance from the new pavilion. Investor wants to build a new object of universal classrooms for ca. 180 students and sports hall with hygienic and technical facilities, which will be able for football club FC Pisek (football fields and central object of FC Pisek are close to neighboring plots). Investor wants to let the school canteen be on the current place, which is north of the new object. The object is designed as a two-floor with roof ascent (3.NP terrace), part of the building is embedded in the ground. The structural system of the school object is a ceramic bricks system, structural system of the sports hall is a reinforced concrete system. The roof of school object is warm flat roof and roof of sport hall is warm flat roof as well but mono-pitched type. The object has a U -shaped.
16

Contribution to digital microrobotics : modeling, design and fabrication of curved beams, U-shaped actuators and multistable microrobots / Contribution à la microrobotique numérique : modélisation, conception et fabrication de poutres bistables, d'actionneurs en U et de microrobots multistables

Hussein, Hussein 11 December 2015 (has links)
Un nombre de sujets concernant la microrobotique numérique ont été abordés dans le cadre de cette the` se. Une nouvelle génération du microrobot numérique ”DiMiBot” a e´ te´ proposé ce qui rend le DiMiBot plus précis, plus contrôlable et plus petit. La nouvelle structure est formée de deux modules multistables seulement, ce qui ajoute des fonctionnalités´ s importantes comme l’augmentation du nombre de positions avec une taille plus réduite et la capacité´ de réaliser des trajectoires complexes dans l’espace de travail. Le principe du nouveau module multistable combine les avantages des microactionneurs pas à pas en termes du principe et du concept numérique en termes de la répétabilité et la robustesse en boucle ouverte. Un mécanisme de positionnement précis, capable de compenser les incertitudes de fabrication a e´ te´ développé et utilise´ pour assurer un positionnement précis. En parallèle, des modèles analytiques ont e´ te´ développés pour les principaux composants dans le DiMiBot: poutres flambées préformées et actionneurs e´ électrothermiques en U. Des méthodes de conception ont été développées par la suite qui permettent de choisir les dimensions optimales garantissant les performances requises en respectant les spécifications et limites de design. Des prototypes de modules multistables, fabrique´ s dans la salle Blanche MIMENTO, ont montré´ un bon Fonctionnement dans les expériences. / A number of topics concerning digital microrobotics were addressed in this thesis. A new generation of the digital microrobot ”DiMiBot” was proposed with several advantages making the DiMiBot more accurate, more controllable and smaller. The new structure consists of only two multistable modules which adds some important features such as increasing the number of positions with smaller size and the ability to realize complex trajectories in the workspace. The principle of the new multistable module combines the advantages of the stepping microactuators in terms of the principle and of the digital concept in terms of the repeatability and robustness without feedback. The accuracy is ensured with an accurate positioning mechanism that compensate the fabrication tolerances. In parallel, analytical models was developed for the main components in the DiMiBot: preshaped curved beams and U-shaped electrothermal actuators. Subsequently, design methods were developed that allow choosing the optimal dimensions that ensure the desired outputs and respecting the design specifications and limitations. Multistable module prototypes, fabricated in the clean room MIMENTO, showed a proper functioning in the experiments.
17

Acute effects of physical exercise of different intensities on working memory : Masters thesis

Johansson, Ludwig January 2023 (has links)
Aim: The purpose of this study was to investigate acute effects of physical exercise of different intensities on working memory. Method: Twelve young adults, 20-40 years, 8 males and 4 females passed the screening and participated in a randomized experimental crossover within-subject design study with three experimental conditions. Working memory was measured with n-back consisting of three difficulty levels.  Results: No significant interaction effect within subjects between the three different exercise intensity conditions for accuracy or response time was found. A significant main effect of time was detected for n-back response time, F(1,11)=40.2, p=&lt;.001, reflecting an overall shorter response time after exercise compared to before, independent of exercise intensity condition. A two-way interaction effect on accuracy was found between n-back session 1 and 2 in the low fitness group.  Conclusions: The exercise intensity does not seem to matter for the improvement of working memory performance. However, participants response time was shown to be faster following any given exercise intensity.
18

Water self-ejection, frosting, harvesting and viruses viability on surfaces: modelling and fabrication

Di Novo, Nicolò Giuseppe 24 October 2022 (has links)
The wettability and phase change phenomena of water are ubiquitous on biological and artificial surfaces. Properties like water repellency, self-cleaning, coalescence induced condensation jumping, anti-frosting, and dew harvesting arise on surfaces with particular structures and chemistry and are of particular interest for energy and water saving. This thesis collects different studies of wettability and phase change on natural and artificial surfaces: growth and self-ejection of condensation droplets on micro and nanostructured surfaces we fabricated, their applications, the Sliding on Frost of condensation droplets observed on the Cotinus Coggygria leaf, the dew harvesting property of the Old Man of the Andes Cactus enhanced by distance coalescence through microgrooves and finally, a theoretical study of viruses viability in sessile droplets. The first chapter introduces the theoretical framework of wettability and phase changes on surfaces. In the second chapter, we present the self-ejection of condensation droplets from hydrophobic nanostructured microstructures. We modelled analytically the droplets jumping and fabricated surfaces to verify the predictions. The fabricated geometry was inspired by the modelling and the available fabrication techniques. We tested the surfaces in condensation conditions. Using a high frame rate camera coupled with a long working distance microscopy objective, we investigated the growth and ejection transient. We then compared the experimental self-ejection velocity for various structures geometry with our analytical models. In Chapter 3, we investigated the applications of the fabricated surfaces reported in Chapter 2. In Chapter 4, we explore the condensation frosting on the leaf of Cotinus Coggygria, native of our woods and with interesting hydrophobic properties. Covered by wax nanotubules, it exhibits coalescence-induced condensation jumpings that may be a useful cleaning tool. Furthermore, the frost is delayed but not only for the jumping. Surprisingly, at temperatures some degrees below zero, we observed what we called ‘droplet Sliding on Frost bridges’, that further delays frosting. We described the feasibility of this sliding in terms of dynamic contact angles of the surface and contact angles of supercooled water on ice. By capturing high temporal and spatial resolution videos we investigated the sliding on frost and droplet recalescence (fast dendrite growth that partially solidify the liquid). The responsible for the failure of sliding for temperatures from about -8 ° C down appears to be the advancing angle of water on ice that increases with the subcooling rather than the recalescence that blocks the drop in place. These results add a piece to the fundamental research on the supercooled water-ice-vapour interfaces. As it often happens, biological surfaces offer a starting point for the study of fundamental mechanisms and the development of artificial surfaces with optimized properties. In the Chapter 5, the multifunctional roles of hairs and spines in Old Man of the Andes Cactus (Oreocereus trolli) are studied. We study the morphology of the appendages, the hairs wettability, mechanical properties of both, and the dew formation on spines. The longitudinal microgrooves on the spines cause a particular phenomenon of distant coalescence (DC), in which smaller droplets flow totally or partially into larger ones through the microgrooves, with consequent accumulation of water in a few large drops. An earlier study has shown artificial micro-grooved surfaces that exhibit DC are more efficient than flat ones at collecting and sliding dew, and thus these cactus spines could act as soil dew conveyors. The agreement between our analytical model and experimental data verifies that the flow is driven by the Laplace pressure difference between the drops. This allowed us to obtain a general criterion for predicting the total or partial emptying of the smaller drops as a function of the dynamic contact angles of a surface. Based on this criterion, an hydrophilic material with small contact angle hysteresis would allow a greater number of complete drops emptying. The COVID-19 pandemic has raised the problem of contagion from airborne and deposited droplets. In the last chapter, we report the state of the art of experiments on the viability of viruses in deposited droplets. Up to date, it has been experimentally highlighted that the relative viability of some viruses (RV) depends on the material chemistry, temperature, and interestingly, on relative humidity (RH) with a U-shaped trend. One of the current hypotheses is that the cumulative dose of salt concentration (CD) affects RV. We model the RV of viruses in sessile droplets by inserting a RV-CD relation in a model of droplet evaporation. By considering a saline water droplet (one salt) as the simplest approximation of real solutions, we analytically simulate the time evolution of salt concentration, vapor pressure, and droplet volume varying contact angles, droplet sizes, and RH in the range 0–100%. The results elucidate some previously not yet well-understood dynamics, demonstrating how three main regimes—directly implicated in nontrivial experimental trends of virus RV—can be recognized as the function of RH. The proposed approach could suggest a chart of a virus fate by predicting its survival time at a given temperature as a function of RH and contact angle. We found a good agreement with experimental data for various enveloped viruses and predicted in particular for the Phi6 virus, a surrogate of coronavirus, the characteristic U-shaped dependence of RV on RH. Given the generality of the model, once experimental data are available that link the vulnerability of a certain virus (such as SARS-CoV-2) to the concentrations of salts or other substances in terms of CD, it is envisioned that this approach could be employed for antivirus strategies and protocols for the prediction/reduction of human health risks associated with SARS-CoV-2 and other viruses.

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