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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.
191

Controlled Synthesis of Nanostructured Two-dimensional Tin Disulfide and its Applications in Catalysis and Optoelectronics

Giri, Binod 07 May 2020 (has links)
Tin disulfide (SnS2) is a two-dimensional (2D) material with excellent properties and high prospects for low-cost solutions to catalytic and optoelectronic applications. In this work, vertical nanoflakes of SnS2 have been synthesized using custom-designed close space sublimation (CSS) system and investigated for applications in photoelectrochemical (PEC) water oxidation and metal-semiconductor-metal (MSM) photodetector. For the PEC application, vertical SnS2 nanoflakes grown directly on transparent conductive substrates have been used as photoanodes, which produce record photocurrents of 4.5 mA cm−2 for oxidation of a sulfite hole scavenger and 2.6 mA cm−2 for water oxidation without any hole scavenger, both at 1.23 VRHE in neutral electrolyte under simulated AM1.5G sunlight, and stable photocurrents for iodide oxidation in acidic electrolyte. This remarkable performance has been attributed to three main reasons: (1) high intrinsic carrier mobility of 330 cm2 V−1 s−1 and long photoexcited carrier lifetime of 1.3 ns in the nanoflakes, (2) the nanoflake height that balances the competing requirements of light absorption and charge transport, and (3) the unique stepped morphology of these nanoflakes that improves photocurrent by exposing multiple edge sites in every nanoflake. In another application, these SnS2 nanoflakes have been used to enhance the performance of lead sulfide quantum dot (PbS QDs) photodetectors by providing a high-mobility channel for photoexcited charges from PbS QDs, which results in 2 orders of magnitude enhancement in responsivity. The physical models and experimental findings presented in this dissertation can help engineer more cost-effective solutions for PEC water splitting and optoelectronics based on 2D metal dichalcogenides.
192

Swahili Palimpsests: The Muslim stories beneath Swahili compositions

Raia, Annachiara 11 September 2019 (has links)
Although a textual relationship between Arabic Muslim texts and their rendition through Swahili epic poems (tendi) is acknowledged in Swahili poetry studies, “translation” is not a straightforward explanation of this relationship. Furthermore, Swahili narrative poems on the prophets (manabii), mostly created at the end of the 19th century, have seldom been considered in textual relation to the Qiṣaṣ al-Anbiyā’ literature or to the Qur’ān. Thus, important questions have not been asked: How did the Arabic stories of the prophets arrive on the Swahili coast? How did poets appropriate these stories and forge them into a new narrative discourse? In this paper, I focus on tafsiri as a form of appropriation and adaptation, applying Gérard Genette’s concept of “palimpsest” to analyse the textual relationship between Arabic Muslim and Swahili literary texts. This will allow me, through a close reading of these texts and consideration of both language and genre, to identify the palimpsestuous presence or rather copresence of Arabic source texts within Swahili works. Ultimately, this method offers a model for future philologies of world literature.
193

Emma Woodhouse, Handsome, Clever, and Rich... and Bisexual? : a study of attraction and impossible things in Jane Austen's Emma / Emma Woodhouse, stilig, klyftig, och rik… och bisexuell? : En studie av attraktion och omöjliga saker i Jane Austens Emma

Jonsson, Natasha January 2021 (has links)
No description available.
194

Diskurzivní pravidla spojené s umíráním: Jak lidé hovoří o smrti blízkých / Discourse Rules Connected to Dying: How People Talk About Death of Close Ones

Exnerová, Dominika January 2016 (has links)
The thesis aims with discourse rules of dying of a close person. Author works with other theories, especially with Gorer's pornography of death and also comparisons of current situation and history of Ariés and Elias, who considered the current representations of death to be more a taboo than in the past. The practical base of the text is a research combining both in-depth interviews with young people and interpretations of closed groups, such as support group and internet discussion. The analysis identified two approaches in young people's families, focusing either on practical aspects of dying of a relative or on emotional aspects. These two approaches were in opposition against each other especially while both being present in a single family. Also, several conditions changing discourse rules were identified. The death of a young person or by suicide were more tabuized than death of an elder person. Generally, the research shows that people's view on death is not constructed by media as Gorer proposed, since young adult people have their own experience from their families. In this text, death is considered to be a taboo of the society because of strict boundaries of what is appropriate and inaproppriate. Powered by TCPDF (www.tcpdf.org)
195

Ensam i en gemenskap - Äldres upplevelser av ensamhet

Sundström, Karin, Wendt, Isabelle January 2020 (has links)
Our aim with this study was to examine older people's experiences of loneliness. Specifically, we investigated how loneliness affects the elderly, how it is expressed, and what its sources are. The study was conducted using a qualitative method, by interviewing four caregivers at two nursing homes, and three social workers who work as care administrators for nursing homes. We found that the experience of loneliness is prevalent among the elderly who live in nursing homes. Furthermore, we identified two outstanding themes in their experiences, which we categorised as experiences of loneliness and feelings of being safe. Feelings of being safe had two subthemes; moving to a nursing home and the living situation. Feelings of being unsafe were closely related to loneliness, and this was partially a reason why the elderly wanted to move to a nursing home, as a way to get closer to other people and overcome loneliness. Experiences of loneliness varied in the following subthemes; suffering of existential loneliness, extent of social relationships, social networks, and social life, expressions of loneliness, and the meaning of loneliness. We found different forms of loneliness, including loneliness based on loss of relationships, mostly due to the passing away of one’s social group, which was expressed partially as an experience of existential loneliness. The elderly people’s network of friends and family varied; some of them had a close network with many visitors every day, and others had almost none that visited them.
196

3D digitalizacija površi bez karakterističnih obeležja primenom blisko-predmetne fotogrametrije / 3D digitization of texture-less surfaces using close-range photogrammetry

Santoši Željko 02 October 2020 (has links)
<p>Kreiranje 3D modela i njihova vizuelizacija postali su sastavni deo procesa razvoja novih ili redizajniranja postojećih proizvoda. U ovom istraživanju pažnja je posvećena re&scaron;avanju problema 3D digitalizacije kod blisko-predmetne fotogrametrije zasnovane na određivanju strukture iz kretanja, na povr&scaron;ima bez karakterističnih obeležja primenom projektovanja sintetički generisanih slika u vidu svetlosnih tekstura. Akcenat je stavljen na generisanje novih sintetičkih slika koje imaju izraženu vizuelnu teksturu, njihovu evaluaciju i primenu na objektima sa monotonim vizuelnim povr&scaron;ima sa ciljem podizanja ukupne tačnosti rekonstruisanih 3D modela. Verifikacija primene sintetičkih slika i njihovih svetlosnih tekstura sa aspekta geometrijske i dimenzione tačnosti je realizovana primenom računarom podržane inspekcije (CAD inspekcije).</p> / <p>The creation of 3D models and their visualization have become an integral part of the process of developing new or redesigning existing products. In this research, attention was paid to solving the problem of 3D digitization in close-range photogrammetry based on the structure from motion on surfaces without characteristic features by designing synthetically generated images in the form of light textures. An accent is placed on the generation of new synthetic images that have a pronounced visual texture, their evaluation, and application on objects with monotonous visual surfaces with the aim of raising the overall accuracy of reconstructed 3D models. The verification of the application of synthetic images and their light textures from the aspect of geometric and dimensional accuracy was realized through the use of computer-aided inspection (CAI inspection).</p>
197

Stabilita hvězd ve dvojhvězdě / Stability of stars undergoing rapid mass loss

Cehula, Jakub January 2021 (has links)
Binary mass transfer is a common phenomenon is stellar astrophysics. If the mass transfer proceeds on dynamical timescale, the binary can undergo a catastrophic interaction accompanied by tremendous loss of mass, angular momentum, and energy. This so-called common envelope evolution phase is a crucial step in the formation of close binaries composed of compact objects (white dwarfs, neutron stars, black holes), which includes progenitors of gravitational wave sources de- tected by LIGO. By improving existing models of binary mass transfer we can correct the predictions of common envelope evolution and constraint the rates of close binaries composed of compact objects. In this work, we introduce new model of binary mass transfer. We will treat the mass transfer as a special case of stellar wind. We will rely on the assumption that the Roche potential sets up a de Laval nozzle around the first Lagrange point. The mass is then transferred through the nozzle. Our binary mass transfer model predicts mass transfer rates in the same order of magnitude as the standard models which use the Bernoulli's law. But the advantage of our model is that it is extendable to account for radiation.
198

Hvězdný vítr a ztráty momentu hybnosti dvojhvězdy / Angular momentum loss from binary systems due to stellar winds

Hubová, Dominika January 2021 (has links)
Massive binary evolution is crucial for our understanding of many pheno- mena in the Universe, such as high-mass X-ray binaries or the formation of compact systems emitting gravitational waves. In this work, we study the loss of angular momentum from binary systems caused by radiation driven stellar winds, which are characteristic for hot, massive stars. Calculating numerically ballistic trajectories of particles ejected from the binary surface, we establish the average specific angular momentum loss as a function of the system's mass ratio for binaries in semidetached and contact stages. We initiate the outflow on the Roche lobes or even on further equipotentials of the Roche potential in case of over-contact systems. Moreover, we implement two models of the radiation driven wind. Firstly, we eject particles from the surface of the binary with a non-zero initial velocity, but we then let them evolve only under the influence of the system's gravity. In the second model, we develop a simple method for computing the radiative acceleration due to the radiation pressure from the bi- nary surface. Our results can be used in further calculations of the evolution of massive binary systems.
199

Krig och poesi i samtida Ryssland : En studie om krigets skildring i Poezija poslednego vremeni: Chronika

Karlsson, Angelica January 2023 (has links)
This study analyzes a recently published collection of poetry on the ongoing Russo-krainian war. Against a background of Russia’s new oppressive laws concerning the fact that a person can be sent to prison for up to 15 years for spreading “false information” about the war the study aims to investigate the way poets express themselves in the collective work Poeziia poslednego vremeni: Khronika, published in Saint Petersburg in the fall of 2022. The study was conducted through content analysis and close reading of selected poems of the collection. Conclusions that was drawn from the study is that the collective work contains poems with a strong anti-war message. Poets take a clear standpoint in the collection against the Russian regime and the war and oftentimes use a satirical and ironic way to undermine both the war and the Russian regime, which is remarkable considering the risk taken when speaking out against the war in today’s Russia.
200

Population-Level Genetic Structure of Acmispon Argophyllus on the Channel Islands of California

Wheeler, Gregory Lawrence 14 December 2013 (has links)
The California Channel Islands present an ideal system in which to study unique biogeographical patterns seen in island systems near a mainland source, where spatial barriers are likely to limit gene flow without disrupting it completely. The islands also harbor a number of endemic taxa, suggesting that isolation from the mainland may be strong for some taxa. For this study, Acmispon argophyllus, a legume species found across five of the eight islands as well as on the mainland was used to test hypotheses at three spatial scales. Northern island populations have diverged into what potentially represents a new species; populations on the younger southern islands descent from populations on the older island of San Clemente; the two taxa on San Clemente show signs of genetic structure, with limited evidence of ongoing gene flow. These results demonstrate isolation over short distances in the Channel Islands leading to evolutionary divergence and speciation.

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