Theses and Dissertations from UMD
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New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a give thesis/dissertation in DRUM
More information is available at Theses and Dissertations at University of Maryland Libraries.
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Item PHOTO-GUIDED SHAPE TRANSFORMATION OF COMPOSITE HYDROGEL SHEETS(2018) Guo, Hongyu; Nie, Zhihong; Chemistry; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Shape-changing hydrogel material has numerous potential applications in biomimetics, soft robotics, biomedicine, etc. Light as a clean energy source can be remotely delivered to material with high spatial and temporal resolution, which brings new controllability to shape-transformation of hydrogel material. However, the current strategy of using light to control deformation of hydrogel is limited. This dissertation aims to develop new approaches to program shape-transformation of hydrogel material by using light. First, I developed a simple and efficient approach to re-program shape-transformation of composite hydrogel sheet with homogeneously distributed silver nanoparticle. By modulating light irradiation pattern, the same hydrogel sheet transformed to multiple distinct geometries, which were verified by finite element method. Secondly, I developed a simple and reliable approach to pattern various types of photo-thermal converting nanoparticles in hydrogel sheet. The approach enables nanoparticle patterning in both lateral and thickness-direction of hydrogel, which cannot be readily achieved by other approaches such as microcontact printing and photo-lithography. Thirdly, I explored shape transformation of composite hydrogel sheet with spatially patterned plasmonic gold nanoparticles fabricated by using the approach mentioned above. The same patterned composite hydrogel sheet can be designed to exhibit distinct shape transformation modes, highly depending on light irradiation direction, which has not been reported before. Fourthly, I studied shape transformation of composite hydrogel sheet spatially patterned with erasable and rewritable iron oxide nanoparticles. The same hydrogel sheet was re-programmed to exhibit various distinct shape transformations by changing nanoparticle pattern. This provides a new method to reprogram shape transitions of hydrogel material by using external light source. In addition, a hydrogel tube was also readily patterned with iron oxide nanoparticles and its deformation was studied as well. Lastly, I developed a simple and general approach to fabricate multifunctional composite hydrogel tube. The hydrogel tube was formed via self-rolling of 2D hydrogel sheet after releasing stress introduced during photo-polymerization. The introduced magnetic nanorod brought multi-functionality to the hydrogel tube. The self-rolled tube was used to load, transport and release cargo manipulated by capillary force, magnet and light, respectively. This dissertation provides a new, simple and efficient toolset to program and re-program shape transformation of composite hydrogel material by using external light. It is believed that the toolset and concept developed in this dissertation can be applied to other light-responsive hydrogel material.Item Light in the Landscape(2013) Thum, Erica Marie; Sullivan, Jack; Plant Science and Landscape Architecture (PSLA); Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This design-research thesis proposes the redesign of Tide Lock Park in Alexandria, Virginia as an exploration of light. By researching the cultural history of artificial lighting as well as the sculptural use of light as art, this thesis seeks to distinguish lighting design that goes beyond functional and safety concerns to include design that honors the human relationship to darkness, as well as the artistic and emotive qualities of lighting. To accomplish these goals, this thesis proposes a landscape design for Tide Lock Park which meets the City of Alexandria's objectives as described in the Waterfront Small Area Plan. The design includes three distinctive areas of light, providing visitors the opportunity to engage the night in multiple ways.Item VISION OF EQUINOX FOR ORCHESTRA(2005-12-01) Chiba, Maiko; Gibson, Robert; Music; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The artistic play of light seen on a pyramid in some Mayan ruins located in Cancun, Mexico provided the inspiration for Vision of Equinox. On both the spring and autumn equinox days, the sunlight projected on the pyramid forms a shape which looks like a serpent moving on the stairway of the pyramid. Vision of Equinox was composed with an image of light as the model for the artistic transfiguration of sound. The light image of sound changes its shape in each stage of the piece, using the orchestra in different ways - sometimes like a chamber ensemble, sometimes like one big instrument. The image of light casting on a pyramid is expressed by descending melodic lines that can be heard several times in the piece. At the final climax of the work, a complete and embodied artistic figure is formed and stated, expressing the appearance of the Mayan god Quetzalcoatl, the serpent, in my own imagination. The light and shadow which comprise this pyramid art are treated as two contrasting elements in my composition and become the two main motives in this piece. To express these two contrasting elements, I picked the numbers "5" and "2," and used them as "key numbers" in this piece. As a result, the intervals of a fifth and a second (sometimes inverted as a seventh) are the two main intervals used in the structure. The interval of a fifth was taken into account for the construction of the pyramid, which has five points of contact. The interval of a second was selected as a contrasting sonority to the fifth. Further, the numbers "5" and "2" are used as the number of notes which form the main motives in this piece; quintuplets are used throughout this piece, and the short motive made by two sixteenth notes is used as one of the main motives in this piece. Moreover, the shape of the pyramid provided a concept of symmetry, which is expressed by the setting of a central point of the music (pitch center) as well as the use of retrograde and inversion in this piece.