京都大学 / 新制・課程博士 / 博士(理学) / 甲第24180号 / 理博第4871号 / 新制||理||1697(附属図書館) / 京都大学大学院理学研究科化学専攻 / (主査)教授 寺西 利治, 教授 島川 祐一, 教授 倉田 博基 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

<p> Light emitting silicon nanostructures are of significant interest for photonics due to their potential to act as the source material for a monolithically integrated Si-based light source. This thesis reports on the experimental characterization of such luminescent structures formed in silicon nitride, oxynitride, and rare earth doped silicon oxide thin films. Changes in the electronic structure of the materials have been analyzed using soft X-ray spectroscopy by probing the constituent elements at their absorption edges. The observed near edge structure at these edges is related to the local atomic bonding environment of the probed atoms. Specifically, changes in the near edge structure at the Si K and L3,2 absorption edges can be related to the coordination of silicon atoms within the films.</p> <p> In the silicon nitrides the Si-clustering process has been observed to onset at different anneal temperatures, dependant on film composition. In films that have a small amount of excess Si higher anneal temperatures are required before a significant Si-Si bonding signal is observed. In samples with high concentrations of excess Si this clustering process is observed to occur at temperatures as low as 700 °C. In silicon oxynitride samples only a small fraction of the excess Si forms into clusters within the films. Rather, in these samples the formation of distinct silicon oxide and silicon nitride phases is observed, with strong absorption related to the formation of the oxide phase being observed after annealing at high temperatures (T ≥ 1000 °C). The nanoclusters were determined to be amorphous in nature, rather than nanocrystalline, through the use of high-resolution, energy filtered, and scanning transmission electron microscopy. This behavior was seen even for samples with high excess Si concentrations and annealed at high temperatures. This contrasts with the behavior of silicon-rich silicon oxide thin films were nanocrystals are clearly observed after similar treatments, indicative of the influence of the nitride host matrix on the cluster formation process.</p> <p> Changes in the electronic structure at these edges have been correlated with changes in the bonding structure within the films, as analyzed through Fourier transform infrared spectroscopy, and with the photoluminescent behavior of the films.</p> <p> X-ray excited optical luminescence (XEOL) has been used for the study of rare earth doped silicon oxides, allowing for site specific excitation of the films in order to analyze the origin of luminescence in the films. In O-rich samples the luminescence of the films has been observed to be strongly excited at O-related absorption edges while in Si-rich samples XEOL is observed at Si-Si bonding absorption energies. The results indicate the presence of different sensitization pathways towards luminescence in the films, including the formation of oxide or silicate phases.</p> / Thesis / Doctor of Philosophy (PhD)

Remote photoelectric monitoring of the locomotion of four freshwater teleosts in an experimental tank established that all species described non-random locomotor patterns which were affected by light intensity. A partial analysis was made of some of the characteristics of these patterns with emphasis on the direction and degree of turning. / Thesis / Doctor of Philosophy (PhD)

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With the intensification of contemporary urbanization, an increasing number of people are living and working in high-density urban environments. The importance of a good indoor environment for human psychology and health is increasingly evident, so researchers are paying more attention to the impact of indoor environments on human health and well-being. This article first extensively searches and organizes theories related to lighting, natural sounds, and indoor environments. Based on this, a mixed method combining qualitative and quantitative research is used to investigate the effects of combining lighting and natural sounds on emotions and productivity. This study intends to provide a scientific basis for the future design of more restorative indoor environments. Finally, the data analysis of the experimental results shows that the environment combined with cool light and natural sound is more helpful in improving people's well-being, restoring people's emotions, and improving people's attention and work efficiency.

As lighting designers, we are aware of the importance of light in constructing dynamic, interesting spaces that enhance the human experience. But light is more than simply a physical component; it also has a rich cultural meaning that affects how we perceive and comprehend the world. This study aims to compare and investigate how the lighting setting of two distinct cultural groups, Indian and Swedish, influence the way people perceive a living room in a residential space when it is used for Diwali and Christmas purposes. It also tries to ascertain whether cultural backgrounds influence the preferences &amp; perception for light in various settings. A qualitative analysis was conducted using three methods in order to compare &amp; learn about lighting cultures in two different cities, Stockholm and New Delhi. As well as to comprehend user perception in two lighting settings, Christmas and Diwali, and to determine whether these perception and preferences are related to the cultural background, habits, or history. The results obtained supported one another and contributed to the research and made a serious effort to understand how different lighting preferences vary among cultures. There were intriguing findings throughout the objectives aimed, illustrating how similar yet different the two lighting cultures are.

The thesis explores the relationship of light, architecture, and humans focusing on both the mathematics of solar movement that informs the architecture and the experiential and spiritual response of human perception to it. The exploration uses the celestial realm as the inspiration and canvas that the design process was built on. The light tunnels, the design concept explored in detail, investigate the consequences of architectural form and space in combination with volumetric, reflected, dispersed, or absorbed light. The design process transforms an instrument derived from the sun dial to a living piece of architecture that responds to human perception to variably objectify and reveal spiritual conditions of the celestial sky. / Master of Architecture / The thesis explores the relationship of light, architecture and humans focusing on both the movement of the sun and the perceptive response to it. The Pilgrimage of the 'temples of inexplicable' is a complex with several pavilions that engage with light and dark to create a space that allows the coexistence of spirituality and science in harmony. The thesis looks into one pavilion in detail – The light tunnels that investigate the movement of the light source, its nature as an object or revelation, and the human perception. The design process transforms an instrument to a living piece of architecture.

The Maritime museum is currently investigating possibilities for an exhibition building housing the ceremony boat the “Royal Barge of Sweden” and 18th century King Gustav III’s leisure boats. I hope to influence this debate with this degree project. The architectural theme of the project has been learning about natural light and its relation to exhibition spaces. The initial research phase consisted of museum visits, research into projects by Gunnar Mattson and a historic comparison of the Maritime museum’s exhibition rooms. The proposed building is in Haga park, connecting to an existing jetty below Vasaslätten’s café. A concrete dry dock with an adjacent exhibition space is the main room of the building, making it possible to use the largest barge on the Brunnsviken waters. The rest of the building parts are smaller wooden pavilions on land, exhibiting the boats that are not in use. A variety of spaces and light conditions are offered. The dry dock is approached from a dark narrow entrance and opens to a bright tall space as one walk down a red carpet. The leisure boat pavilions are lit from underneath, giving the impression of the boats floating in another element.

In Gaza, daily blackouts have lasted for over eleven years. Until recently, Palestinian families have received only four hours of power each day. Since Israel’s withdrawal from the region in 2005, the political discourse around the Right of Return has forced refugees to live in terrible conditions and darkness. The fear was that any transformation of the camps will bring about an integration of the refugee community with the local environment and thus any improvements to Gaza’s infrastructure and housing was seen as a direct erosion of the Right of Return. Can bringing light to Gaza transcend this boundary of temporality and restore hope to this impoverished community? With recent solar lighting ideas emerging to help solve Gaza’s energy shortage by solar energy companies such as SunBox and LittleSun, I plan to develop a solar urban lighting project for Gaza’s smallest refugee camp - Deir al-Balah (DEB) - to help improve security at night for residents and provide the community with opportunities to socialise in public common areas. In response to an ‘Improvement Plan’ conducted by the United Nations Relief and Works Agency (UNRWA) in 2017, which identifies DEB camp’s limited access to electricity and street lighting, I’d like to explore how a solar and ecologically-sensitive lighting programs can improve Gazan’s daily lives, by bringing clean, reliable and affordable energy access.

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