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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.
211

Construções geométricas e origami

Bonfim, Marcelo January 2016 (has links)
Orientador: Prof. Dr. Sinuê Dayan Barbero Lodovici / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Mestrado Profissional em Matemática em Rede Nacional, 2016. / Geometry is present in many of our contemporary activities, which allows us to search for more contextualized teaching strategies in order to make the learning process more meaningful to the student. Folding square papers to create origami, seems, to some extent, something simple, seeing that since our childhood, we play folding paper, making boats, balloons or even aircrafts. However, much more than just folding randomly, Origami is based on basic geometry and without realizing it, we work with angles, planes, lines and points, enabling several ways to work with Geometry with this technique inside the classroom, in a playful and interesting way, arising the students¿ curiosity. Thus this thesis aims to present a proposal to approach in a more playful way the fundamental knowledge of Euclidean Geometry through Origami. In this work we broach two of the three classic and insolvable problems of Euclidean geometry using the ruler and the ideal compass, showing some possible elementary frames with only these two instruments. We also mention the constructability of certain numbers using the ruler and the ideal compass. Finally, we discourse about the Japanese technique of Origami, the axioms that substantiate its geometry as well as demonstrate the resolution for two of these insolvable problems: the angle trisection and the duplication of a cube. / A Geometria faz-se presente em várias de nossas atividades contemporâneas, o que nos permite buscar estratégias de ensino mais contextualizadas, de maneira que a aprendizagem seja mais significativa ao aluno. Fazer dobraduras em papel parece, até certo ponto, algo simples, visto que, desde a nossa infância brincamos com a dobradura em papel, seja fazendo barcos, balões ou aviões. Porém, muito além do ato de apenas dobrar de maneira qualquer, o Origami é fundamentado em conhecimentos básicos da Geometria e sem percebermos, trabalhamos com ângulos, planos, retas e pontos, possibilitando diversas formas de se trabalhar a Geometria com esta técnica em sala de aula, de maneira lúdica e interessante, despertando a curiosidade do aluno. Desta forma, esta dissertação busca apresentar uma proposta para abordar de maneira mais lúdica os conhecimentos fundamentais da Geometria Euclidiana através do Origami. Neste presente trabalho abordamos sobre dois dos três problemas clássicos e insolúveis da Geometria Euclidiana utilizando a régua e o compasso ideais, abordando algumas construções elementares possíveis com apenas esses dois intrumentos. Abordamos também sobre a construtibilidade de determinados números utilizando a régua e o compasso ideais. Por fim, discorremos sobre a técnica japonesa do Origami, os axiomas que fundamentam sua geometria, bem como a demonstração da resolução de dois desses problemas insolúveis: a trissecção do ângulo e a duplicação do cubo.
212

Light and single-molecule coupling in plasmonic nanogaps

Chikkaraddy, Rohit January 2018 (has links)
Plasmonic cavities confine optical fields at metal-dielectric interfaces via collective charge oscillations of free electrons within metals termed surface plasmon polaritons (SPPs). SPPs are confined in nanometre gaps formed between two metallic surfaces which creates an optical resonance. This optical resonance of the system is controlled by the geometry and the material of the nanogap. The focus of this work is to understand and utilize these confined optical modes to probe and manipulate the dynamics of single-molecules at room temperature. In this thesis, nanogap cavities are constructed by placing nanoparticles on top of a metal-film separated by molecular spacers. Such nanogaps act as cavities with confined optical fields in the gap. Precise position and orientation of single-molecules in the gap is obtained by supramolecular guest-host assembly and DNA origami breadboards. The interaction of light and single-molecules is studied in two different regimes of interaction strength. In the perturbative regime molecular light emission from electronic and vibrational states is strongly enhanced and therefore is used for the detection of single-molecules. In this regime the energy states remain unaltered, however profound effects emerge when the gap size is reduced to < 1 nm. New hybridized energy states which are half-light and half-matter are then formed. Dispersion of these energies is studied by tuning the cavity resonance across the molecular resonance, revealing the anti-crossing signature of a strongly coupled system. This dressing of molecules with light results in the modification of photochemistry and photophysics of single-molecules, opening up the exploration of complex natural processes such as photosynthesis and the possibility to manipulate chemical bonds.
213

As interações discursivas no ensino de geometria por meio de técnicas de dobradura e outras atividades lúdicas : um estudo de caso em uma turma do 3º ano do ensino fundamental

Paixão, Tereza Cristina dos Santos 24 March 2017 (has links)
The objective of this research was to analyze the development of a didactic sequence elaborated and geared to the teaching of geometry through folding techniques and other play activities, verifying their contributions to the conceptual evolution and motor skills of the students. The research was developed with students of the 3rd year of elementary school of a state school, located in the municipality of Nossa Senhora do Socorro, in Sergipe. It is a qualitative research on the practice itself. Modality defined by João Paulo da Ponte as a research on the practice itself (PPP). In this perspective, the researcher acted as teacher of the group investigated. The analytical focus, taking into account a sociocultural perspective of education, turned mainly to the discursive interactions configured in the classroom everyday, which were analyzed based on theories of Vygotsky and Bakhtin, as well as in some Analytical categories proposed by Mortimer and Scott. The data were obtained and treated with inspiration in the interactional ethnography. Through filming and field notes, the actions of the teacher and students were recorded. Each class of the didactic sequence, recorded in video, was mapped in episodes, which were submitted to the analysis, and the most representative ones were transcribed, and their analysis was deepened. The obtained results indicate that the interactions guided and fomented by the teacher in the classroom, as well as the mediating tools used by them favored the development and learning of the mathematical content explored, contributed to the evolution of the students' motor skills, enabled the dialogue with Art and the formation of the basic concepts of geometry. / Esta pesquisa teve por objetivo analisar o desenvolvimento de uma sequência didática elaborada e voltada para o ensino de geometria, por meio de técnicas de dobraduras e outras atividades lúdicas, verificando as suas contribuições para a evolução conceitual e de habilidades motoras dos alunos. A pesquisa foi desenvolvida com alunos do 3º ano do Ensino Fundamental de uma escola estadual, localizada no município de Nossa Senhora do Socorro, em Sergipe. Trata-se de uma pesquisa qualitativa sobre a própria prática. Modalidade definida por João Paulo da Ponte como pesquisa sobre a própria prática (PPP). Nessa perspectiva, a pesquisadora atuava como professora da turma investigada. O foco analítico, tendo-se em vista uma perspectiva sociocultural de educação, voltou-se, principalmente, para as interações discursivas configuradas no cotidiano da sala de aula, as quais foram analisadas com base nas teorias de Vygotsky e Bakhtin, bem como em algumas categorias analíticas propostas por Mortimer e Scott. Os dados foram obtidos e tratados com inspiração na etnografia interacional. Por meio de filmagens e anotações de campo, as ações da professora e dos alunos foram registradas. Cada aula da sequência didática, registrada em vídeo, foi mapeada em episódios, os quais foram submetidos à análise, sendo que os mais representativos foram transcritos, tendo sua análise aprofundada. Os resultados obtidos indicam que as interações guiadas e fomentadas pela professora em sala de aula, bem como as ferramentas mediadoras por ela utilizadas favoreceram o desenvolvimento e a aprendizagem do conteúdo matemático explorado, contribuíram para a evolução das habilidades motoras dos alunos, possibilitaram o diálogo com Arte e a formação dos conceitos básicos de geometria.
214

Development of experimental and analysis methods to calibrate and validate super-resolution microscopy technologies / Développement de méthodes expérimentales et d'analyse pour calibrer et valider les technologies de microscopie de super-résolution

Salas, Desireé 27 November 2015 (has links)
Les méthodes de microscopie de super-résolution (SRM) telles que la microscopie PALM (photoactivated localization microscopy), STORM (stochastic optical reconstruction microscopy), BALM (binding-activated localization microscopy) et le DNA-PAINT, représentent un nouvel ensemble de techniques de microscopie optique qui permettent de surpasser la limite de diffraction ( > 200 nm dans le spectre visible). Ces méthodes sont basées sur la localisation de la fluorescence de molécules uniques, et peuvent atteindre des résolutions de l'ordre du nanomètres (~20 nm latéralement et 50 nm axialement). Les techniques SRM ont un large spectre d'applications dans les domaines de la biologie et de la biophysique, rendant possible l'accès à l'information tant dynamique que structurale de structures connues ou non, in vivo et in vitro. Beaucoup d'efforts ont été fournis durant la dernière décennie afin d'élargir le potentiel de ces méthodes en développant des méthodes de localisation à la fois plus précise et plus rapide, d'améliorer la photophysique des fluorophores, de développer des algorithmes pour obtenir une information quantitative et augmenter la précision de localisation, etc. Cependant, très peu de méthodes ont été développées pour examiner l'hétérogénéité des images et extraire les informations statistiquement pertinent à partir de plusieurs milliers d'images individuelles super-résolues. Dans mon travail de thèse, je me suis spécifiquement attaquée à ces limitations en: (1) construisant des objets de dimensions nanométriques et de structures bien définies, avec la possibilité d'être adaptés aux besoins. Ces objets sont basés sur les origamis d'ADN. (2) développant des approches de marquage afin d'acquérir des images homogènes de ces objets. (3) implémentant des outils statistiques dans le but d'améliorer l'analyse et la validation d'images. Ces outils se basent sur des méthodes de reconstruction de molécules uniques communément appliquées aux reconstructions d'images de microscopie électronique. J'ai spécifiquement appliqué ces développements à la reconstruction de formes 3D de deux origamis d'ADN modèles (en une et trois dimensions). Je montre comment ces méthodes permettent la dissection de l'hétérogénéité de l'échantillon, et la combinaison d'images similaires afin d'améliorer le rapport signal sur bruit. La combinaison de différentes classes moyennes ont permis la reconstruction des formes tridimensionnelles des origamis d'ADN. Particulièrement, car cette méthode utilise la projection 2D de différentes vues d'une même structure, elle permet la récupération de résolutions isotropes en trois dimensions. Des fonctions spécifiques ont été adaptées à partir de méthodologies existantes afin de quantifier la fiabilité des reconstructions et de leur résolution. A l'avenir, ces développements seront utiles pour la reconstruction 3D de tous types d'objets biologiques pouvant être observés à haute résolution par des méthodologies dérivées de PALM, STORM ou PAINT. / Super resolution microscopy (SRM) methods such as photoactivated localization microscopy (PALM), stochastic optical reconstruction microscopy (STORM), binding-activated localization microscopy (BALM) and DNA-PAINT represent a new collection of light microscopy techniques that allow to overpass the diffraction limit barrier ( > 200 nm in the visible spectrum). These methods are based on the localization of bursts of fluorescence from single fluorophores, and can reach nanometer resolutions (~20 nm in lateral and 50 nm in axial direction, respectively). SRM techniques have a broad spectrum of applications in the field of biology and biophysics, allowing access to structural and dynamical information of known and unknown biological structures in vivo and in vitro. Many efforts have been made over the last decade to increase the potential of these methods by developing more precise and faster localization techniques, to improve fluorophore photophysics, to develop algorithms to obtain quantitative information and increase localization precision, etc. However, very few methods have been developed to dissect image heterogeneity and to extract statistically relevant information from thousands of individual super-resolved images. In my thesis, I specifically tackled these limitations by: (1) constructing objects with nanometer dimensions and well-defined structures with the possibility of be tailored to any need. These objects are based on DNA origami. (2) developing labeling approaches to homogeneously image these objects. These approaches are based on adaptations of BALM and DNA-PAINT microscopies. (3) implemented statistical tools to improve image analysis and validation. These tools are based on single-particle reconstruction methods commonly applied to image reconstruction in electron microscopy.I specifically applied these developments to reconstruct the 3D shape of two model DNA origami (in one and three dimensions). I show how this method permits the dissection of sample heterogeneity, and the combination of similar images in order to improve the signal-to-noise ratio. The combination of different average classes permitted the reconstruction of the three dimensional shape of DNA origami. Notably, because this method uses the 2D projections of different views of the same structure, it permits the recovery of isotropic resolutions in three dimensions. Specific functions were adapted from previous methodologies to quantify the reliability of the reconstructions and their resolution.In future, these developments will be helpful for the 3D reconstruction of any biological object that can be imaged at super resolution by PALM, STORM or PAINT-derived methodologies.
215

Konceptutveckling av justerbart solcellstak för fritidsbåtar : Ett utvecklingsprojekt med syfte att öka laddningskapaciteten för elektriska fritidsbåtar / Concept development of adjustable photovoltaic sunroof for leisure boats

Friberg, Sebastian January 2021 (has links)
Denna rapport redovisar processen och resultatet av ett examensarbete som utgör en del av examinationen för högskoleingejörsexamen i innovationsteknik och design vid Karlstads universitet. Projektet är gjort på uppdrag av Glava Energy Center för Bowters räkning med uppdraget att ta fram lösningar som kan utöka laddningskapaciteten för elektriska fritidsbåtar. Examensarbetet utfördes vårterminen 2021 och omfattar 22.5 högskolepoäng. Projektet är uppbyggt kring fem faser, planering, discover, define, develop och deliver där syftet är att först identifiera rätt problem för att sedan kunna komma fram till rätt lösning. Det finns flera sätt att angripa detta projekt, speciellt om man väljer att fokusera på varför laddningskapaciteten behöver utökas från första början, vissa av dessa lösningar blir tyvärr också irrelevanta på grund av faktorer som berör kostnader eller tekniska aspekter. Detta arbete har därför identifierat och utvecklat lösningar som genom att installera fler solceller kan utöka laddningskapaciteten. På båten finns det flera ställen att installera solceller på, men det är svårt att bortse från att en av de bättre platserna ur effektsynpunkt är att placera solceller på något typ av tak där de inte blir skuggade, men vad tycker egentligen användarna om det? En användarintervju utfördes som gav svar på detta. Användarna kan tänka sig att ett tak är en bra sak att ha när det bli riktigt varmt eller man bara vill njuta av lite skugga som omväxling men att man förmodligen är ute med båten för att just få njuta av solen. Ett tak som går att fälla undan eller justera på något annat sätt skulle kunna vara en lösning på det problemet. En mängd olika taklösningar samt icke taklösningar har undersökts men efter användandet av olika kända sållningsmetoder stod det klart att arbetet skulle gå vidare med en taklösning som är delvis justerbar, alternativt helt fast. Detta har lett fram till att tre koncept tagits fram som alla bidrar med en utökad laddningskapacitet. Koncept Glidande stomme och Skjutbart tak bygger på en enkel konstruktion som tillåter en respektive två standard solpaneler att forma ett tak över båten. De olika koncepten kan justeras till olika positioner för att på det sättet kunna erbjuda användarna en variation av skugga och sol utefter tycke och smak. Koncept Origami flasher bygger som namnet hintar om på ett vikmönster från den traditionella konstformen origami. Detta koncept är lite mer experimentellt men ger i teorin ett väldigt stort skydd från solen i utfällt läge samt stor yta för montering av solceller, samtidigt som det i hopfällt läge täcker absolut minst yta av dessa tre koncept vilket är fördelaktigt för de användare som vill njuta av solen. / This thesis presents the process and it’s results from a concept development project. The thesis is part of the examination for a Bachelor of Science in Innovation Technology and Design at Karlstad University. The project was commissioned by Glava Energy Center on behalf of Bowter with the task of developing solutions that can increase the charging capacity for electric leisure boats. The thesis was written during spring 2021 and comprises 22.5 credits. The project is built around five phases, planning, discover, define, develop and deliver. The purpose is to first identify the right problem in order to be able to produce the right solution. There are several ways to approach this project, especially if you choose to focus on why the charging capacity needs to be increased in the first place, some of these solutions unfortunately also become irrelevant due to factors affecting costs or technical aspects. This work has therefore identified and developed solutions which, by installing more solar cells, can increase the charging capacity. There is several places on the boat that are suitable for install solar cells, but it is difficult to ignore that, from a power point of view, the best place to instal solar cells is on some sort of roof. But what does the user really think about it? A pre-study, including a intervju with users was conducted that provided answers to this question. The user can imagine that a roof is a good thing to have when it gets really hot or when you just want to enjoy a little shade for a change, but that the real objective with the usage of the boat probably is to enjoy the sun. A roof that can be folded away or adjusted in some other way could be a solution to that problem. A variety of roof solutions and non-roof solutions have been investigated. After the use of various known screening methods it was decided that the work would continue with a roof solution that is partially adjustable, or completely solid. The project have after that chosen to present three concepts that contribute to an increased charging capacity by help of a partially adjustable roof. Concept Glidande stomme and Skjutbart tak is based on a fairly simple construction that allows one respectively two standard solar panels to form a roof over the boat. The different concepts can be adjusted to different positions in order to offer users a variety of shade according to taste and needs. Concept Origami flasher, as the name suggests, is based on a folding pattern from the traditional art of origami. This concept is a bit more experimental but provides, in theory, second largest protection from the sun in unfolded  position. Meanwhile, in collapsed position, the Origami flasher concept covers the least area of ​​these three concepts, which is advantageous for those users who want enjoy the sun.
216

Developing New Techniques for Investigating Static and Dynamic Magnetic Degrees of Freedom

Sheffield, Matthew E. January 2018 (has links)
No description available.
217

Selective Deposition of Metallic and Semiconductor Materials onto DNA Templates for Nanofabrication

Liu, Jianfei 30 November 2011 (has links) (PDF)
This work examines the selective deposition of metallic and semiconductor materials onto DNA templates for the fabrication of nanodevices. DNA origami provides a simple and robust method for folding DNA into a variety of shapes and patterns and makes it possible to create the complex templates needed for nanodevices, such as nanoelectronic circuits, plasmonics, and nanosensors. Metallization of DNA origami templates is essential for the fabrication of such nanodevices. In addition, selective deposition of semiconductor materials onto the DNA template is of importance for making many nanodevices such as nanocircuits. Metallization of DNA origami presents several challenges beyond those associated with the metallization of other DNA templates such as λ-DNA. All of these challenges were addressed in this study. DNA origami templates were seeded with Ag and then plated with Au via electroless deposition. Selective continuous metal deposition was achieved, with an average metallized height as small as 32 nm. The structure of T-shaped DNA origami was also retained after metallization. Following the metallization of complete origami, site-specific metallization of branched DNA origami was also demonstrated. To achieve this, staple strands at select locations on origami were replaced with staple strands modified with binding sites at the end. These binding sites then attached to thiolated DNA coated Au nanoparticles through base pairing. The continuous Au nanowires formed at designated sites on DNA origami after Au plating had an average width of 33 nm, with the smallest ones ~20 nm wide. The continuity of nanowires was verified by conductivity tests- the only tests of this nature of which I am aware. Moreover, predesigned sites on "circuit-shaped" DNA origami were successfully metallized. The selective deposition of a variety of materials onto DNA templates for the formation of continuous DNA-templated nanowires was also demonstrated. Specifically, an electroless Ni plating solution was developed to enable the fabrication of uniform and continuous DNA-templated Ni nanowires. Tests showed that these DNA-templated Ni nanowires were conductive. Moreover, continuous DNA-templated Bi2Te3 and/or Te nanowires have been fabricated through galvanic displacement of DNA-templated Ni and Cu nanowires. Altogether, these results represent important progress toward the realization of DNA-templated nanofabrication.
218

Quantitative Modeling of DNA Systems

Crocker, Kyle A. January 2021 (has links)
No description available.
219

The Art of Designing DNA Nanostructures with CAD Software

Glaser, Martin, Deb, Sourav, Seier, Florian, Agrawal, Amay, Liedl, Tim, Douglas, Shawn, Gupta, Manish K., Smith, David M. 05 May 2023 (has links)
Since the arrival of DNA nanotechnology nearly 40 years ago, the field has progressed from its beginnings of envisioning rather simple DNA structures having a branched, multi-strand architecture into creating beautifully complex structures comprising hundreds or even thousands of unique strands, with the possibility to exactly control the positions down to the molecular level. While the earliest construction methodologies, such as simple Holliday junctions or tiles, could reasonably be designed on pen and paper in a short amount of time, the advent of complex techniques, such as DNA origami or DNA bricks, require software to reduce the time required and propensity for human error within the design process. Where available, readily accessible design software catalyzes our ability to bring techniques to researchers in diverse fields and it has helped to speed the penetration of methods, such as DNA origami, into a wide range of applications from biomedicine to photonics. Here, we review the historical and current state of CAD software to enable a variety of methods that are fundamental to using structural DNA technology. Beginning with the first tools for predicting sequence-based secondary structure of nucleotides, we trace the development and significance of different software packages to the current state-of-the-art, with a particular focus on programs that are open source.
220

The Structure of Chromatin and its Influence on Gene Regulation

Bernier, Morgan Welsh January 2014 (has links)
No description available.

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