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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.
221

Evidence for Volatile Organic Compound Mass Reduction Adjacent to Hydraulically Induced, ZVI-Filled Fractures in Clay

Ramdial, Brent 18 May 2012 (has links)
Volatile organic compound (VOC) contamination of low permeability geologic deposits due to Dense Non-Aqueous Phase Liquid (DNAPL) penetration through fractures is exceptionally difficult to remediate using in-situ methods as the low permeability of the sediments limits the delivery of reagents proximal to contaminant mass. This thesis examines in detail the extent of organic contaminant treatment away from hydraulically-induced fractures injected with particulate Zero Valent Iron as (1) ZVI and glycol (G-ZVI) and (2) an emulsified ZVI (EZVI) mixture within a contaminated glaciolacustrine clayey deposit. Continuous vertical cores were collected through the treatment zone at 2 and 2.5 years after substrate injections and soil sub-sample spacing was scaled to show the extent of the treatment zone adjacent to the ZVI in the fractures, expecting the treatment would be controlled by diffusion limited transport to the reaction zone. Analytical results show evidence of treatment in both the EZVI and the G-ZVI containing fractures with the presence of degradation by-products and reduced VOC concentrations in the fracture and surrounding clay matrix. / Natural Sciences and Engineering Research Council of Canada, University Consortium for Field-Focused Groundwater Contamination Research
222

Synthesis, characterization and physicochemical properties of platinum naboparticles on ordered mesoporous carbon

Saban, Waheed January 2011 (has links)
In this study SBA-15 mesoporous silica template was synthesized and used as a sacrificial template in the preparation of ordered mesoporous carbon material. A chemical vapour deposition (CVD) technique using LPG or alternatively sucrose, pyrolyzed upon a mesoporous Si matrix were used to produce nanostructured ordered mesoporous carbon (OMC) with graphitic character after removing the Si template. The sucrose method was found to be a suitable route for preparing OMC. The OMC was used as a conductive three dimensional porous support for depositing catalytic nanophase Pt metal. Deposition of Pt nanoparticles on OMC was accomplished using a CVD method with Pt(acac)2 as a precursor. The synthesized nano-composite materials were characterized by several techniques such as, HRTEM, HRSEM, EDS, XRD, BET, TGA, FT-IR and CV.
223

High temperature superconducting thin films and quantum interference devices (SQUIDs) for gradiometers

Graf zu Eulenburg, Alexander January 1999 (has links)
No description available.
224

Conductive anodic filament reliability of fine-pitch through-vias in organic packaging substrates

Ramachandran, Koushik 13 January 2014 (has links)
This research reports for the first time conductive anodic filament reliability of copper plated-through-vias with spacing of 75 – 200 µm in thin glass fiber reinforced organic packaging substrates with advanced epoxy-based and cyclo-olefin polymer resin systems. Reliability studies were conducted in halogenated and halogen-free substrates with improved test structure designs including different conductor spacing and geometry. Accelerated test condition (temperature, humidity and DC bias voltage) was used to investigate the effect of conductor spacing and substrate material influence on insulation reliability behavior. Characterization studies included gravimetric measurement of moisture sorption, extractable ion content analysis, electrical resistance measurement, impedance spectroscopy measurement, optical microscopy and scanning electron microscopy analysis and elemental characterization using energy dispersive x-ray spectroscopy. The accelerated test results and characterization studies indicated a strong dependence of insulation failures on substrate material system, conductor spacing and geometry. This study presents advancements in the understanding of failure processes and chemical nature of failures in fine-pitch copper plated-through-vias in newly developed organic substrates and demonstrates potential methods to mitigate failures for high density organic packages.
225

Fundamental study of growth of (Zn,Cd)Se on GaAs (211)B from hetero-interface to nanostructures

Telfer, Samantha Anne January 2000 (has links)
No description available.
226

MBE growth and characterisation of ZnSe-based II-VI semiconductors

O'Donnell, Cormac Brendan January 2000 (has links)
No description available.
227

The poetics of making

Ho, King Tong Unknown Date (has links)
This is a practice-led research project that seeks to explore the cross-cultural aesthetics and conceptual ideas of an art project. I position myself as an art practitioner who intends to apply the Western modes of technological advancement of digital imaging and ink jet technologies to the substrates used by traditional Chinese artists for ink painting and calligraphy, usually called Xuan Zhi [宣紙]. Through this process, the aesthetics and conceptual ideas of both cultures will be explored, examined, analysed and interrogated for the potential development of a new aesthetics in the context of digital art. There are three major components in this research project; a creative document in the form of a collection of artwork, an exegesis and a collection of documentation. The creative document will be a body of visual image-based artwork that includes a series of collateral works from the ongoing research and practice of the project. It is the negotiated output of a potentially new aesthetics in digital art, specifically in the context of digital still imaging and digital printmaking. The exegesis is an analytical and critical commentary that places the creative document in relevant theoretical, philosophical, cultural and historical contexts. The documentation is a collection of the ongoing empirical practice of ink jet technology on Xuan Zhi. The visual physical form of both the exegesis and the documentation are also included as part of the creative document. These three components together form a unity and are presented as artefacts to represent the main focus of the research - the Poetics of Making.
228

Morphological Control of Multifunctional Mesoporous Silica Nanomaterials for Catalysis Applications

Seong Huh January 2004 (has links)
Thesis (Ph.D.); Submitted to Iowa State Univ., Ames, IA (US); 19 Dec 2004. / Published through the Information Bridge: DOE Scientific and Technical Information. "IS-T 2397" Seong Huh. US Department of Energy 12/19/2004. Report is also available in paper and microfiche from NTIS.
229

Mechanisms of microstructure development at metallic-interlayer/ceramic interfaces during liquid-film-assisted bonding

Sugar, Joshua D. January 2003 (has links)
Thesis (M.S.); Submitted to the University of California, Berkeley, CA (US); 1 Dec 2003. / Published through the Information Bridge: DOE Scientific and Technical Information. "LBNL--54185" Sugar, Joshua D. USDOE Director. Office of Science. Basic Energy Sciences (US) 12/01/2003. Report is also available in paper and microfiche from NTIS.
230

RIZOGÊNESE IN VITRO E ACLIMATIZAÇÃO DE Luehea divaricata Mart. & Zucc. / RHIZOGENESIS IN VITRO AND ACCLIMATIZATION OF Luehea divaricata Mart. & Zucc.

Silva, Karol Buuron da 19 February 2016 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In front of the need to recover the original forest cover of the Atlantic Forest, it is necessary to adopt restoration programs of deforested areas using native species. Luehea divaricata Martius et Zuccarini, popularly known as açoita-cavalo, is a native tree specie of the Atlantic Forest biome widely used for the recovery of areas. It is a forest species that has its wood used for many different purposes, which contributed to the reduction of their natural populations, causing difficulties to find viable seeds of the species. Given this fact, the micropropagation becomes a viable alternative for the production of high quality seedlings, providing thus the formation of healthy populations for use in restoration projects of degraded areas. This way, this study aimed to optimize the rooting in vitro process and acclimatization of the species, and, for this, different concentrations of salts of the WPM nutritive medium for in vitro root formation shoots of Luehea divaricata were initially evaluated. Then, the effects of the addition indolebutyric acid (IBA) as a treatment "pulse" and naphthaleneacetic acid (NAA) in the nutritive medium were studied for rooting in vitro specie. The effect of the combination of vermiculite volume with the nutritive medium WPM/2 in root formation in vitro of Luehea divaricata was also analyzed in this study, as well as the implication of sucrose and different concentrations of substrates in the species acclimatization. The nutritive medium WPM/2 showed the most promising results for the development of Luehea divaricata, reaching values of 44,52% in the formation of primary roots after 45 days of in vitro culture. Treatment "pulse" with different concentrations of IBA and the use of NAA concentrations are not efficient for in vitro root formation in Luehea divaricata. The combinations of 20mL of nutritive medium + 15cm³ vermiculite, 20mL of nutritive medium + 30cm³ of vermiculite and 30mL of nutritive medium + 30cm³ of vermiculite were more promising for in vitro root formation in the species, providing averages of 39,61% in the rooting after 45 days of cultivation. Finally, for acclimatization in vitro and ex vitro substrates based on bio-stabilized pinus bark or based on turf, calcareous calcitic and composted pinus bark may be used, independently of sucrose concentrations tested during in vitro cultivation. / Diante da necessidade de recuperação da cobertura florestal original do bioma Mata Atlântica, é imprescindível a adoção de programas de restauração de áreas desmatadas utilizando espécies florestais nativas. Luehea divaricata Martius et Zuccarini, conhecida popularmente como açoita-cavalo, é uma espécie florestal nativa do bioma Mata Atlântica muito utilizada para a recuperação de áreas. Trata-se de uma espécie florestal que tem sua madeira empregada para as mais diversas finalidades, fato que contribuiu para a redução de suas populações naturais, ocasionando dificuldades para encontrar sementes viáveis da espécie. Diante desse fato, a micropropagação torna-se uma alternativa viável para a produção de mudas de alta qualidade, propiciando, assim, a formação de populações sadias para o uso em projetos de recuperação de áreas degradadas. Face ao exposto, o presente trabalho teve como objetivo otimizar os processos de enraizamento in vitro e aclimatização da espécie, e, para isso, foram avaliadas, inicialmente, diferentes concentrações dos sais do meio nutritivo WPM na rizogênese in vitro de brotações de Luehea divaricata. Em seguida, foram estudados os efeitos da adição, ao meio nutritivo, do Ácido Indolbutírico (AIB) como tratamento pulse e do Ácido Naftalenoacético (ANA) para o enraizamento in vitro da espécie. O efeito da combinação do volume de vermiculita com o meio nutritivo WPM/2 na rizogênese in vitro de Luehea divaricata também foi analisado, bem como a implicação de concentrações de sacarose e diferentes substratos na aclimatização da espécie. Os resultados obtidos indicam que o meio nutritivo WPM/2 apresentou resultados mais promissores para o desenvolvimento de Luehea divaricata, alcançando valores de 44,52% na formação de raízes primárias aos 45 dias de cultivo in vitro. O tratamento pulse com diferentes concentrações de AIB e o emprego de concentrações de ANA não são eficientes para a rizogênese in vitro de Luehea divaricata. As combinações de 20mL de meio nutritivo + 15cm³ de vermiculita, 20mL de meio nutritivo + 30cm³ de vermiculita e 30mL de meio nutritivo + 30cm³ de vermiculita são mais promissoras na rizogênese in vitro da espécie, proporcionando médias de 39,61% no enraizamento aos 45 dias de cultivo. Por fim, para a fase de aclimatização in vitro e ex vitro podem ser utilizados os substratos à base de casca de pinus bio-estabilizada e à base de turfa, calcário calcítico e casca de pinus compostada, independentemente das concentrações de sacarose testadas durante o cultivo in vitro.

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