Xiao, Manda = 金納米晶修飾的空心介孔二氧化矽微球在表面等離子體激元調製下的光散射行為 / 肖蔓達. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references. / Abstracts in English and Chinese. / Xiao, Manda = Jin na mi jing xiu shi de kong xin jie kong er yang hua xi wei qiu zai biao mian deng li zi ti ji yuan diao zhi xia de guang san she xing wei / Xiao Manda. / Abstract --- p.i / 摘要 --- p.iii / Acknowledgement --- p.iv / Table of Contents --- p.vi / List of Figures --- p.viii / List of Tables --- p.x / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Plasmonic Properties of Noble Metal Nanocrystals --- p.1 / Chapter 1.2 --- Light Scattering from Dielectric Spheres --- p.6 / Chapter 1.3 --- Motivations and Outline of the Thesis --- p.9 / Chapter 2 --- Characterization Techniques --- p.17 / Chapter 2.1 --- Instrumentation --- p.17 / Chapter 2.2 --- Extinction Measurement of Au Nanocrystals and the HMSMSs Decorated with the Au Nanocrystals --- p.17 / Chapter 2.3 --- Sample Preparation for the TEM and SEM Characterization --- p.18 / Chapter 2.4 --- Dark-Field Imaging and Spectroscopy of the Individual Microspheres --- p.19 / Chapter 3 --- Fabrication of Hollow Mesoporous Silica Microspheres Decorated with the Au Nanocrystals --- p.25 / Chapter 3.1 --- Preparation of the Hollow Mesoporous Silica Microspheres --- p.25 / Chapter 3.2 --- Growth of the Au Nanocrystals --- p.29 / Chapter 3.3 --- Assembly of the Au Nanocrystals onto the Hollow Mesoporous Silica Microspheres --- p.32 / Chapter 4 --- Resonant Scattering Properties of the Hollow Mesoporous Silica Microspheres --- p.38 / Chapter 4.1 --- Experimental Results --- p.38 / Chapter 4.2 --- Calculation of the Scattering Spectra by Mie Theory --- p.42 / Chapter 4.3 --- Summary --- p.46 / Chapter 5 --- Resonant Scattering Properties of the Au Nanocrystal-Decorated Hollow Mesoporous Silica Microspheres --- p.49 / Chapter 5.1 --- Effect of the Plasmon Resonances of the Au Nanocrystals on the Resonant Scattering Behaviors of the HMSMSs --- p.49 / Chapter 5.2 --- Estimation of the Scattering Enhancement Factors --- p.54 / Chapter 5.3 --- Summary --- p.59 / Chapter 6 --- Summary --- p.61

[Truncated abstract] Many researchers have proposed the use of silicate rock fertilizers (SRFs) as alternatives to chemical fertilizers. However, the application of SRFs in modern agricultural practices is limited due mainly to the slow release of plant-nutrient elements from SRFs and consequently many tonnes/ha of SRFs may need to be applied. Simple and inexpensive methods of modifying the physicochemical properties of SRFs are needed to improve the agronomic effectiveness of SRFs. This thesis is focused on the evaluation of high-energy milling to produce superfine particles to improve the effectiveness of mafic (basalt and dolerite) and felsic (gneiss and K-feldspar) rocks for use as fertilizers. The ground mafic rocks are for use as Ca and Mg fertilizers and the ground felsic rocks as K fertilizers. Laboratory and glasshouse experiments were conducted with several potential SRFs. In laboratory experiments, initially milled rocks (Ø< 250 μm for basalt, dolerite, and gneiss; Ø < 150 μm for K-feldspar) were further milled with a ball mill (Spex-8000) for 10, 30, 60, 90, and 120 min under dry and wet (rock/water ratio = 1/3) conditions. To investigate possible reaction between constituents, other subsamples of initially milled basalt, dolerite, and gneiss were added to reagent grade NaCl or KCl (4.5 g rock + 0.5 g NaCl or KCl) and milled for 120 min under dry and wet conditions. Basalt and dolerite were also mixed with K-feldspar at a ratio of 1 : 1 and milled for 120 min under dry and wet conditions. For use in the glasshouse experiment, the initially milled rocks were further milled with a vertical stirred ball mill for 1 h in a dry condition. The elemental and mineralogical compositions of the SRFs were determined using XRF and XRD. Effects of milling on major physicochemical properties of milled rocks were determined, including particle size (Malvern Mastersizer), surface area (BET-N2), quantities of amorphous constituents (XRD, oxalic acid-oxalate extraction, TEM), extractable cations (1M CH3COONH4 pH 7), pHH2O, and electric conductivity. Dissolution kinetics in 0.01M acetic-citric acids (for 56 days) and soil (for 10 months) were determined. Based on the results of these laboratory experiments, a glasshouse experiment was carried out for 12 months to evaluate the effects of SRF application on growth and nutrient uptake of ryegrass grown on several soils. Milling reduced particle size, enhanced amorphism, and increased the release of structural cations from the rocks, with the effects due to dry milling being greater than for wet milling. The optimum milling times which produced maximum amounts of exchangeable cations (Na, K, Ca, and Mg) were 30 - 90 min, depending on rock type. The use of NaCl and KCl as milling additives did not enhance the properties of the SRF

Thesis (M.Sc.) - Carleton University, 2005. / Includes bibliographical references (p. 153-163). Also available in electronic format on the Internet.

Tez (Yüksek Lisans) - Süleyman Demirel Üniversitesi, Fen Bilimleri Enstitüsü, Maden Mühendisliği Anabilim Dalı, 2008. / Bibliyografya var.

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Made available in DSpace on 2014-10-09T12:49:57Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:02:47Z (GMT). No. of bitstreams: 0 / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:49:57Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:02:47Z (GMT). No. of bitstreams: 0 / Os argilominerais são elementos estruturais do solo multiplamente aplicados segundo suas propriedades. A caracterização desse material se faz cada vez mais necessária por fatores tecnológicos, ambientais, ecológicos e legais. Neste âmbito disponibilizar uma metodologia rápida, segura e eficiente é especialmente relevante. Neste trabalho são descritos dois procedimentos, o primeiro para identificar os argilominerais encontrados em solos argilosos por difração de raios X e o segundo para determinar quantitativamente os macro e micro constituintes da argila por fluorescência de raios X (WDXRF), aplicando-se o método de parâmetros fundamentais, que, não utiliza curvas de calibração. Esses procedimentos foram aplicados em cinco amostras de solo cedidas por uma empresa de médio porte, localizada em Ipube, Pe. Os resultados por difração de raios X mostraram a predominância dos argilominerais caulinita e ilita, os quais, foram confirmados por meio das análises quantitativas dos elementos majoritários por fluorescência de raios X. Os resultados para os elementos minoritários foram comparados com os valores orientadores para solo publicados pela CETESB. / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Selected outcrops of the Upper Devonian to Lower Carboniferous, Witteberg Group, Cape Supergroup were mineralogically and structurally analyzed. The study area is located approximately 30km northwest of Kirkwood and 10km south of Darlington Dam, Eastern Cape, South Africa. Strata predominantly consist of arenaceous Witpoort Formation, which includes the Perdepoort, and Rooirand Members. The Perdepoort Member is a thinly bedded quartzite also known as the "white streak". The Rooirand Member quartzite is a highly iron stained red-brown quartzite. The dark-grey, pyritic rich shales of the Kweekvlei Formation overlie the Witpoort Formation in the southern half of the study site. These shales are highly deformed and display closely spaced thrust faults and close folds. The study area encapsulates a range of folding from tight to open folds. Faulting consists of low angle north verging thrust fault, south verging back thrusts, south and north dipping normal faults, and strike-slip faults. Closely spaced, fore-land verging thrusts faults predominate over hinterland verging back thrusts. Normal faulting post-dates thrust faulting and utilized weaknesses in axial planar cleavage and in certain instances existing thrust fault planes. Strike-slip faulting post-dates thrusting and has in places reactivated pre-existing thrust fault planes. Macro scale folding includes overturned synclines and large anticlines which have been eroded, exposing older strata. Fold axes plunge at low to moderate angles west-southwest. This correlates with tension gashes which indicate north westward directed forces. Eastward directed forces are confirmed by the presence of tension gashes and strike-slip movement. The local geology displays north westward directed compression followed by strike-slip movement. Normal faulting post-dates all other structures and is associated with the Mesozoic break-up of Gondwana. The Perdepoort Member was sampled along strike, at different outcrop latitudes. Seven samples were selected for scanning electron microscope analysis. Samples are composed almost entirely of quartz; accessories include, biotite, muscovite, sericite, baryte, and apatite. Epigenetic hematite is present along cracks within certain samples Epigenetic hematite occur along cracks with oxides and phosphates in the form of rutile, apatite and monazite present in a number of samples. When compared to other silica extraction operations the Perdepoort Member appears viable for explotation. However, for the solar cell industry the purity of this horizon is clearly far below that required for industy.

This study of ATR-IR involved taking spectra of various silicate minerals in powder samples, finding similarities and differences in nature, and locating various bands and intensities of absorption bands for identification and classification purposes. This study is limited to 4000-300 cm-1 with major emphasis on absorptions in the 2000-300 cm-1 region.

We examined the effect of the pore dimension of zeolites on the separation of gas mixtures using atomistic simulation methods. We studied two categories of the zeolites with small pores: pore modified silicalite for H₂/CH₄separation and small pore silica zeolites for CO₂/CH₄separation. The effect of pore modification of silicalite on the H₂/CH₄separation was examined. Under some degrees of surface modification, the CH₄flux was reduced much more than the H₂flux, resulting in high ideal selectivities. The use of small pore zeolites for CO₂/CH₄separations was studied. In DDR, we showed that CO₂diffusion rates are only weakly affected by the presence of CH₄, even though the latter molecules diffuse very slowly. Consequently, therefore, the permeance of CO₂in the equimolar mixtures is similar to the permeance for pure CO₂, while the CH₄permeance in the mixture is greatly reduced relatively to the pure component permeance. The calculated CO₂/CH₄separation selectivities are higher than 100 for a wide range of feed pressure, indicating excellent separation capabilities of DDR based membranes. Inspired by the observation in DDR we also examined the separation capabilities of 10 additional pure silica small pore zeolites for CO₂/CH₄separations. From these considerations, we predict that SAS, MTF and RWR will exhibit high separation selectivities because of their very high adsorption selectivities for CO₂over CH₄. CHA and IHW, which have similar pore structures to DDR, showed comparable separation selectivities to DDR because of large differences in the diffusion rates of CO₂and CH₄.