A framework to compartmentalize microfluidic surfaces was developed. Substrates are separated from surface modifying agents with an intermediate binding layer (IBL). The IBL is comprised of two compounds which bind together using a non-covalent interaction; a host compound is immobilized on the substrate, and a guest compound is conjugated to the surface modifying agent. The primary benefit of the IBL architecture is adaptability: substrates and surface compounds become modular components with standard connectors. Beta-Cyclodextrin (BCD) and adamantane (AD) were selected as the model immobilized host and conjugated guest, respectively. A quartz crystal microbalance (QCM) was assembled and developed to study the BCD/AD complexation interaction. Kinetic, thermodynamic, and Langmuir isotherm data were reported for AD-derivatives binding with immobilized BCD. QCM was also used to investigate neutravidin (NA) binding onto AD-PEG and AD-PEG-biotin coatings immobilized to t-BCD surfaces. QCM was an effective platform to validate the use of BCD/AD as the IBL interaction prior to microfluidic implementation. The BCD/AD IBL was successfully demonstrated in a microfluidic environment. Microfluidic devices were fabricated using the soft-lithographic technique. Adapted surface modifications were visualized using fluorescein isothiocyanate (FITC) probes within the microfluidic device and detected using confocal laser scanning microscopy (CLSM). Surface modifications were applied to demonstrate the fundamental functions of surface passivation, specific binding, and visualization using the IBL architecture. Consistent with QCM data, AD-PEG passivated the surface and AD-PEG-biotin specifically bound NA to the BCD surface. Thus, an adaptable surface modification architecture for microfluidic applications was developed and demonstrated.

A modified Split Hopkinson Pressure Bar (SHPB) system is used to determine the mechanical properties of soft and ultra-soft materials. An aluminum bar is introduced to reduce the impedance mismatch between the test system and sample. The small signal of the forces was measured by a quartz crystal gauge system. The high precision Laser gap gauge (LGG) system was used to measure the deformation of samples. The compressive tests of Cemented Paste Backfill (CPB), fresh CPB and Polymethylmethacrylate (PMMA) and the fracture toughness tests of PMMA were conducted to approve the legitimacy of our modified SHPB system. From these experiments, the efficiency and economy of the modified SHPB system were attested.

This thesis presents ab-initio quantum mechanical calculations at the density functional theory (DFT) level on defect centers hosted by crystalline systems of geologic importance (i.e. fluorite, quartz, stishovite). The research brings new, complementary data to the current understanding of defect structures in minerals and explores the advantages of a theoretical approach in the field of mineral spectroscopy. This present research presents the first ab-initio calculations of the O23- type defects in crystalline solids. New data on the electronic properties and structural characteristics of O23--Y3+ defect in fluorite-type structures (CaF2 and SrF2) were obtained at the DFT level. These results confirm the stability and the molecular character of the O23--Y3+ center, revealing a spin density that is equally distributed between the two oxygen atoms. Our results report an O-O bond distance of 2.47 Å in CaF2 and 2.57 Å in SrF2. The calculated 17O and 19F hyperfine constants for of the O23--Y3+ center are in good agreement with their corresponding experimental values reported by previous electron paramagnetic resonance (EPR) and electron nuclear double resonance (ENDOR) studies, while discrepancies are notable for the 89Y hyperfine constants and are probably attributable to an inadequate basis set for Y.<p> The present study provides a more complete picture of the coupled Al-M substitution for Si in quartz, while investigating the characteristics and electronic properties of the diamagnetic [AlO4/M+]0 (where M = H, Li, Na and K) defects. The diamagnetic [AlO4/M+(a<)]0 defects with M = H, Li and Na have been shown to be more stable than their [AlO4/M+(a>)]0 structural analogues (where a> and a< denote the location of the charge compensating ion on the long-bond and short-bond side, respectively), correctly predicting the common occurrence of paramagnetic [AlO4/M+(a>)]+ centers. The present study confirms previous suggestions that incorporation of the [AlO4/M+]0 defects results in significant structural relaxations that extend at least to the nearest Si atoms. The [AlO4/K+]0 defects have been investigated for the first time and are shown to be stable in quartz. The results of this study have implications for the uptake of Al in quartz.<p> The present research evaluates the structural models of [AlO4/Li] paramagnetic defects in α-quartz. The results confirm the previous experimental findings and propose an additional paramagnetic defect [AlO4/Li+(csmall)]+, with the unpaired electron located on a short-bonded O atom and the Li compensator just off the edge of the small channel. Accordingly we suggest that three distinct Al-Li paramagnetic defects can be can be found in quartz, two of them having the hole located on a short-bonded O and one trapping the hole on a long-bonded O atom. However the structural similarities with the [AlO4/Li+(a>)]+ defect would require detection and measurement of the 17O hyperfine structure for an unequivocal EPR identification.<p> The present work also reports on first-principles quantum-mechanical calculations on the previously proposed [O23--Al3+] defect in stishovite. Our results show that the unpaired spin is 85% localised on one of the six oxygen atoms at an AlO6 octahedron, while the calculated 27Al hyperfine constants are similar to those determined by EPR experiments. Accordingly we propose the Al center to represent an [AlO6]0 defect, and hole hoping among equivalent oxygen atoms is responsible for its detection only at cryogenic temperatures. Theoretical calculations also show that diamagnetic precursors [AlO6/H+]0, [AlO6/Li+]0 and [AlO6/Na+]0 are stable in stishovite. The calculated OH bond distance and orientation are in excellent agreement with those inferred from FTIR spectra and previous theoretical calculations. The calculated [AlO6/Li+]0 and [AlO6/Na+]0 defects suggest that monovalent cations such as Li+ and Na+ are potentially important in accommodating Al in stishovite in the lower mantle.

A modified Split Hopkinson Pressure Bar (SHPB) system is used to determine the mechanical properties of soft and ultra-soft materials. An aluminum bar is introduced to reduce the impedance mismatch between the test system and sample. The small signal of the forces was measured by a quartz crystal gauge system. The high precision Laser gap gauge (LGG) system was used to measure the deformation of samples. The compressive tests of Cemented Paste Backfill (CPB), fresh CPB and Polymethylmethacrylate (PMMA) and the fracture toughness tests of PMMA were conducted to approve the legitimacy of our modified SHPB system. From these experiments, the efficiency and economy of the modified SHPB system were attested.

A framework to compartmentalize microfluidic surfaces was developed. Substrates are separated from surface modifying agents with an intermediate binding layer (IBL). The IBL is comprised of two compounds which bind together using a non-covalent interaction; a host compound is immobilized on the substrate, and a guest compound is conjugated to the surface modifying agent. The primary benefit of the IBL architecture is adaptability: substrates and surface compounds become modular components with standard connectors. Beta-Cyclodextrin (BCD) and adamantane (AD) were selected as the model immobilized host and conjugated guest, respectively. A quartz crystal microbalance (QCM) was assembled and developed to study the BCD/AD complexation interaction. Kinetic, thermodynamic, and Langmuir isotherm data were reported for AD-derivatives binding with immobilized BCD. QCM was also used to investigate neutravidin (NA) binding onto AD-PEG and AD-PEG-biotin coatings immobilized to t-BCD surfaces. QCM was an effective platform to validate the use of BCD/AD as the IBL interaction prior to microfluidic implementation. The BCD/AD IBL was successfully demonstrated in a microfluidic environment. Microfluidic devices were fabricated using the soft-lithographic technique. Adapted surface modifications were visualized using fluorescein isothiocyanate (FITC) probes within the microfluidic device and detected using confocal laser scanning microscopy (CLSM). Surface modifications were applied to demonstrate the fundamental functions of surface passivation, specific binding, and visualization using the IBL architecture. Consistent with QCM data, AD-PEG passivated the surface and AD-PEG-biotin specifically bound NA to the BCD surface. Thus, an adaptable surface modification architecture for microfluidic applications was developed and demonstrated.

No description available.

This thesis presents ab-initio quantum mechanical calculations at the density functional theory (DFT) level on defect centers hosted by crystalline systems of geologic importance (i.e. fluorite, quartz, stishovite). The research brings new, complementary data to the current understanding of defect structures in minerals and explores the advantages of a theoretical approach in the field of mineral spectroscopy. This present research presents the first ab-initio calculations of the O23- type defects in crystalline solids. New data on the electronic properties and structural characteristics of O23--Y3+ defect in fluorite-type structures (CaF2 and SrF2) were obtained at the DFT level. These results confirm the stability and the molecular character of the O23--Y3+ center, revealing a spin density that is equally distributed between the two oxygen atoms. Our results report an O-O bond distance of 2.47 Å in CaF2 and 2.57 Å in SrF2. The calculated 17O and 19F hyperfine constants for of the O23--Y3+ center are in good agreement with their corresponding experimental values reported by previous electron paramagnetic resonance (EPR) and electron nuclear double resonance (ENDOR) studies, while discrepancies are notable for the 89Y hyperfine constants and are probably attributable to an inadequate basis set for Y.<p> The present study provides a more complete picture of the coupled Al-M substitution for Si in quartz, while investigating the characteristics and electronic properties of the diamagnetic [AlO4/M+]0 (where M = H, Li, Na and K) defects. The diamagnetic [AlO4/M+(a<)]0 defects with M = H, Li and Na have been shown to be more stable than their [AlO4/M+(a>)]0 structural analogues (where a> and a< denote the location of the charge compensating ion on the long-bond and short-bond side, respectively), correctly predicting the common occurrence of paramagnetic [AlO4/M+(a>)]+ centers. The present study confirms previous suggestions that incorporation of the [AlO4/M+]0 defects results in significant structural relaxations that extend at least to the nearest Si atoms. The [AlO4/K+]0 defects have been investigated for the first time and are shown to be stable in quartz. The results of this study have implications for the uptake of Al in quartz.<p> The present research evaluates the structural models of [AlO4/Li] paramagnetic defects in α-quartz. The results confirm the previous experimental findings and propose an additional paramagnetic defect [AlO4/Li+(csmall)]+, with the unpaired electron located on a short-bonded O atom and the Li compensator just off the edge of the small channel. Accordingly we suggest that three distinct Al-Li paramagnetic defects can be can be found in quartz, two of them having the hole located on a short-bonded O and one trapping the hole on a long-bonded O atom. However the structural similarities with the [AlO4/Li+(a>)]+ defect would require detection and measurement of the 17O hyperfine structure for an unequivocal EPR identification.<p> The present work also reports on first-principles quantum-mechanical calculations on the previously proposed [O23--Al3+] defect in stishovite. Our results show that the unpaired spin is 85% localised on one of the six oxygen atoms at an AlO6 octahedron, while the calculated 27Al hyperfine constants are similar to those determined by EPR experiments. Accordingly we propose the Al center to represent an [AlO6]0 defect, and hole hoping among equivalent oxygen atoms is responsible for its detection only at cryogenic temperatures. Theoretical calculations also show that diamagnetic precursors [AlO6/H+]0, [AlO6/Li+]0 and [AlO6/Na+]0 are stable in stishovite. The calculated OH bond distance and orientation are in excellent agreement with those inferred from FTIR spectra and previous theoretical calculations. The calculated [AlO6/Li+]0 and [AlO6/Na+]0 defects suggest that monovalent cations such as Li+ and Na+ are potentially important in accommodating Al in stishovite in the lower mantle.

Middle-Late Ordovician Mt. Wilson Quartzite, southern British Columbia, Canada, is a supermature quartz arenite deposited in shallow marine-marginal marine environments on the Early Paleozoic western Laurentian passive margin. Facies-stacking patterns indicate the Mt. Wilson Quartzite is an unconformity bounded, 2nd-order depositional sequence, containing two 3rd-order sequences, and numerous parasequences. Detrital zircon age spectra of six samples of the Mt. Wilson Quartzite have numerous peaks that are unique to Middle to Late Ordovician quartz arenites of western Laurentia. The main peaks, 1800-2000 Ma, 2000-2200 Ma, and 2300-2400 Ma are interpreted to have been derived from basement rocks that were exposed east of the study area: Trans-Hudson Orogeny (1800-2000 Ma), Taltson Orogen (1800-2000 Ma), Buffalo Head Terrane (2000-2400 Ma), Paleoproterozoic crust (2000-2400 Ma), and the Wopmay Terrane (2000-2400 Ma). It is likely that these areas were sourced by local rivers and tributaries draining the Transcontinental Arch and delivered sediment to the deposition location of the Mt. Wilson Quartzite. While longshore transport was a viable distribution method for sediment along the passive margin, it is unlikely that the Peace River Arch (located northwest of the Mt. Wilson Quartzite) was its sole point source; rather it is more likely that there were multiple sediment sources for these western Laurentian quartz arenites. Temporal changes in provenance indicate different areas of basement rock were exposed throughout the deposition of the Mt. Wilson Quartzite, most likely reflecting long-term flooding of North America. The potential for spatial changes in provenance remains unsolved.

Closed-vessel microwave assisted volatilization of Ge, Se, Si and quartz as their volatile compounds , for the determination of trace impurities in high purity Ge, Se, Si and quartz is reported. The volatilization of Ge is 98.7% using vapors of aqua regia whereas vapors generated from 72:1 ratio of HCl:HNO3 is required to volatilize 99.2% of Se. Using vapor of 10:5 ratio of HF:HNO3 , the volatilization of Si is 98.6%, and the volatilization of quartz is 99.0% with 15:3 ratio of the mixed acids. The recoveries of Mg, Cr, Mn,, Ni, Co, Cu, Zn, Cd, Ba and Pb are in the range 83-116%. Determinations are carried out using inductively coupled plasma mass spectrometer with Dynamic Reaction CellTM (DRC ICP-MS). Isobaric interferences, due to the formation of 40Ar12C+, 35Cl16OH+, 40Ar16O+ and 40Ar74Ge+ on the determination of 52Cr+, 56Fe+ and 114Cd+, have been alleviated using ammonia cell gas in DRC. Matrix volatilization using in situ generated acid vapors in closed containers resulted in sub ng mL-1 experimental blanks. Method detection limits are in the low ng g-1 level. The methods developed have been applied to determine trace impurities in high purity Ge, Se, Si and quartz samples.

This research studies 6 eclogites from Qinglongshan Donghai in the Sulu ultrahigh-pressure (UHP) province, eastern China. Petrographic microscope, Ramam spectrometer, scanning electron microscope (SEM) and transmission electron microscope (TEM) are utilized to identify mineral compositions, microstructures and mineral precipitates. Optical observations show the eclogites with the following mineral assemblage: garnet + omphacite + amphibole + epidote + rutile ¡Ó quartz ¡Ó phengite ¡Ó kyanite ¡Ó coesite pseudomorph ¡Ó apatite ¡Ó talc. Oriented mineral precipitates are found within omphacite and within apatites. The parallel precipitates in omphacite are quartz rods confirmed by electron probe microanalysis (EPMA) and TEM diffraction patterns. The direction of the long axes of the quartz rods seem to have relation with the cleavage and with the parting of omphacite. The direction of the long axis of quartz is not necessarily the c axis direction of quartz. Pargasite is intergrown with quartz and the amounts of both minerals seem to have a positive relation. Pargasite contain element K which is not found in omphacite and there is no obvious crystallographic relation between quartz, pargasite, and omphacite. There is amphibole exsolved from the omphacite and the crystallographic axes of tht exsolved amphibole parallel to those of omphacite. The a and c parameters for the two phases are equal while the b parameter of the amphibole is almost twice that of omphacite. A two-stage growth mechanism for quartz and amphibole intergrown within omphacite is proposed: (1) very fine quartz rods exsolved (or aided with infilling fluids) from a supersilicic clinopyroxene during decompression, creating grain boundaries between quartz rods and host, (2) growth of amphibole and quartz along the grain boundaries with fluid participation and an expense of omphacite during retrograde metamorphism. There are two different precipitates within apatites in different eclogites. One of the precipitates is calcium sulfate (anhydrite or gypsum) and the other is ferrous sulfide (pyrrhotite?). There was no report about calcium sulfate within apatite in UHP rocks before. The formation of sulfide (reduced) or sulfate (oxidized) is controlled by the fugacity of oxygen. According to the previous reports and the discoveries of this research, there are many different kinds of precipitates containing silicate incompatible elements in apatites. It can¡¦t be ruled out that the precipitates exsolved from apapites but apatites are more likely to act as sinks of silicate incompatible elements and different minerals precipitated within apatites under different redox conditions rather than exsolution processes.