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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.
1

Continuous and batch hydrothermal synthesis of metal oxide nanoparticles and metal oxide-activated carbon nanocomposites

Xu, Chunbao. January 2006 (has links)
Thesis (Ph. D.)--Chemical and Biomolecular Engineering, Georgia Institute of Technology, 2007. / Teja, Amyn, Committee Chair ; Kohl, Paul, Committee Member ; Liu, Meilin, Committee Member ; Nair,Sankar, Committee Member ; Rousseau, Ronald, Committee Member.
2

Transmission electron microscopy study of growth of oxide film in nanoparticles of Cr and Fe /

Chan, Chun Man. January 2003 (has links)
Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2003. / Includes bibliographical references (leaves 58-59). Also available in electronic version. Access restricted to campus users.
3

Formation and characterization of metal and metal oxide nanoparticles

Glaspell, Garry, January 1900 (has links)
Thesis (Ph. D.)--West Virginia University, 2004. / Title from document title page. Document formatted into pages; contains xiv, 138 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references.
4

Estudos das propriedades ópticas e estruturais dos vidros borosilicatos dopados com érbio e prata

Souza, Lucelia Celes de 23 July 2013 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-04-26T14:29:57Z No. of bitstreams: 1 luceliacelesdesouza.pdf: 2518264 bytes, checksum: 5865f748ffb87158bf1150d3a418b955 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-13T12:02:24Z (GMT) No. of bitstreams: 1 luceliacelesdesouza.pdf: 2518264 bytes, checksum: 5865f748ffb87158bf1150d3a418b955 (MD5) / Made available in DSpace on 2017-05-13T12:02:24Z (GMT). No. of bitstreams: 1 luceliacelesdesouza.pdf: 2518264 bytes, checksum: 5865f748ffb87158bf1150d3a418b955 (MD5) Previous issue date: 2013-07-23 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Os vidros borosilicato são obtidos a partir da combinação dióxido de silício (SiO2) com o óxido de boro (B2O3). Onde estes vidros possuem um vasto campo de aplicações na indústria vidreira, indo deste os setores de equipamentos de laboratórios até a criação de sensores ópticos (fibras ópticas). Pois, devido à sua forma estrutural estes vidros possuem uma grande resistência a choques térmicos, uma boa durabilidade química e uma excelente resistividade elétrica se comparados com os demais vidros existentes hoje no mercado. Assim baseando-se nestas características importantes características estruturais, físicas, químicas e também na diversidade de aplicações optou-se nesta pesquisa pela síntese e caracterização dos vidros borosilicatos puros e dopados com íons terras raras de érbio e com nitrato de prata. Com o objetivo de conhecer melhor as principais propriedades destas matrizes vítreas desenvolvidas e de como os íons emissores, as nanopartículas metálicas ou ambos se comportam quando estes se encontram inseridos nelas, ou seja, de comprovar que a inserção dos dopantes nas matrizes vítreas de borosilicato modificam tanto as suas propriedades ópticas quanto as estruturais. Assim foram utilizadas as seguintes técnicas de caracterização: análise térmica diferencial, medida de densidade, índice de refração linear, absorção óptica e microscopia eletrônica de transmissão. Visto que à inserção dos íons de érbio em materiais vítreos oferece grandes possibilidades de aplicações tecnológicas nos setores das telecomunicações, com o objetivo de aumentar a capacidade de transmissão de dados. E quanto a inserção das nanopartículas de prata pode se dizer que a mesma produz efeitos ópticos não lineares de terceira ordem nos compósitos e em comprimentos de onda próximos da característica de ressonância de plasmon superficial dos aglomerados de metal. Logo, a partir dos resultados e das análises obtidas foi possível comprovar que as amostras de vidro borosilicato produzidas nesta pesquisa apresentaram resultados satisfatórios e que são similares aos encontrados nas literaturas pertinentes, mostrando que esse é um material promissor para diversas aplicações tecnológicas na área de materiais e óptica. / The borosilicate glasses are obtained from the combination of silicon dioxide (SiO2) with boron oxide (B2O3). Where these glasses have a wide range of applications in the glass industry, the sectors of going this laboratory equipment to the creation of optical (fiber optics). Because, due to its structural form these glasses have a large thermal shock resistance, good chemical durability and excellent electrical resistivity compared with other glasses on the market today. Therefore based on these important structural features, physical, chemical, and also in the variety of applications in this study was chosen for synthesis and characterization of pure borosilicate glass and doped with rare earth ions erbium and silver nitrate. In order to better understand the main properties of these glass matrices developed and how the ion emitters, or both metal nanoparticles behave when they are inserted in them, that , to prove that the insertion of dopants in borosilicate glass matrix changes both their optical and structural properties. We used the following characterization techniques: differential thermal analysis, density measurement, linear refractive index, optical absorption and transmission electron microscopy. Since the insertion of erbium ions in glassy materials has great potential for technological applications in the telecommunications, aiming to increase the capacity of data transmission. And the inclusion of silver nanoparticles nonlinear optical effect of third order in the composites and at wavelengths close to the characteristic surface plasmon resonance of the metal clusters. Thus, from the results and analysis obtained was possible to prove that the samples of borosilicate glass produced in this study showed satisfactory results that are similar to those found in the relevant literature, showing that this is a promising material for technological applications in the area of materials and optics.
5

Metallic nanostructure synthesis using DNA origami molds

Helmi, Seham 14 September 2018 (has links)
The past decade has witnessed a breakthrough in the field of structural DNA nanotechnology, which utilizes DNA molecules as a construction material rather than as simple carriers of the genetic information. With the superior programmability of DNA, sub-nanometer precision in the self-assembly of various complex two- and three-dimensional nanostructures is achievable. It also allows a site-specific placement of different objects and functional groups onto the formed structures. This has enabled the assembly of highly sophisticated nanostructures for various applications. While the field of structural DNA nanotechnology has been astonishingly advancing, many nanoelectronics-relevant structures are made of inorganic materials, and DNA-based nanostructures have shown rather low conductivity. This has limited the use of DNA structures in nanoelectronics and reflected the need for a similar programmable route for the inorganic nanofabrication. A conceivable solution would use DNA nanostructures in a way that will precisely transfer the structural information of the DNA shapes into fabricated metallic nanostructures. One way to do that is to use the DNA nanostructures as templates for external material deposition onto the DNA surface. While this strategy has been effective in proving the concept of DNA-shape transfer, metallic nanostructures fabricated this way have shown some drawbacks, such as showing rough surface morphologies and lacking the required homogeneity for the fabricated metallic structures. An alternative strategy would be to design DNA mold structures that can dictate the shape of metal that is “cast” inside such a DNA container. The main topic of my thesis concerns the second strategy. To discuss this in detail, the structure and some of the important properties of DNA are introduced in section 1.1. In section 1.2 the main milestones in the development of the DNA-nontechnology field are discussed and section 1.3 focuses on previous fabrication approaches of DNA-based metallic nanostructures.

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