Physical Sciences and Mathematics Commons^™

Studies Of Microscopic Scale Strains In Nickel Alloys Resulting From Mechanical And Chemical Forces, Jing Chao

Electronic Thesis and Dissertation Repository

The nickel-based Alloy 600, also known as Inconel 600 has been found to be susceptible to stress corrosion cracking (SCC) in high temperature aqueous environments. Despite extensive research, the mechanisms by which this process occurs remain in question. It is known that SCC results from the simultaneous effects of a chemically corrosive environment and a tensile stress. Many studies have been conducted on the microscopic chemical changes associated with SCC. There have been fewer studies of the microscopic stress/strain process. The main objective of this thesis is to use the new x-ray based diffraction technique – polychromatic x-ray microdiffraction (PXM) …

In-Capillary Reduction And Digestion Of Proteins At Nano-Liter Volume Using Capillary Electrophoresis, Thasneen Naina Nazeema

Electronic Thesis and Dissertation Repository

To analyze the proteins present in biological samples several major steps are involved. One of the crucial steps in proteomics has been sample preparation. Prior to mass spectral analysis proteins containing disulfide bonds must be reduced which is followed by digestion. In this work, a novel way of performing protein reduction and digestion at nano-liter volume using capillary electrophoresis is presented. In this work, zone passing CE technique was utilized to analyze the reduction products in CE. After the successful in-capillary reduction, digestion of protein was also performed. A pH mediated stacking was used to bring the reduced protein and …

Fundamental Studies And Bioanalytical Applications Of Nanostructured-Initiator Mass Spectrometry (Nims), Jin Li

Electronic Thesis and Dissertation Repository

Nanostructured-Initiator Mass Spectrometry (NIMS), which uses ‘initiator’ molecules trapped within a nanostructured material to assist the release and ionization of intact molecules adsorbed on that material's surface upon laser or ion irradiation, is a new soft desorption/ ionization technique with several positive attributes including extraordinarily high detection sensitivities, relatively simple sample preparation protocols, and can be initiated using photon or ion irradiation sources. As result NIMS has a great deal of potential for the ready detection of small molecules from complex biofluids including metabolites, and for tissue imaging.

In the thesis, a variety of nanostructured materials including porous silicon (pSi), …

Analysis Of Adp-Ribosylation And Protein Sample Preparation By Capillary Electrophoresis, Ming Huang

Electronic Thesis and Dissertation Repository

ADP-ribosylation is one of many biologically important protein post-translational modifications (PTMs) that received considerable research interest in the past decade. The first part of this work presents the analysis of ADP-ribosylation, with special focus on the catalytic domain of an enzyme ARTD-10. The application of capillary electrophoresis (CE) is proposed in this work to separate the in vitro enzymatic mono-ADP-ribosylated ARTD-10 catalytic domain and its unmodified form. Another exciting aspect of CE application with growing interest is the sample preparation. The effectiveness and efficiency for in-vial reaction, in-capillary mixed reaction and on-capillary-tip reaction by performing methyl esterification on phophopeptides were …

Investigations Of Zeolite Growth By Atomic Force Microscopy (Afm), Donghan Chen

Electronic Thesis and Dissertation Repository

Zeolites are microporous materials that have been used extensively in various fields. A better understanding on their crystallization process is important for their investigations. Atomic force microscopy (AFM) is a powerful tool for studying the growing traces on the crystal surface, providing information regarding the relation between surface events and framework structure. This thesis mainly focuses on the surface investigation of several zeolites and microporous materials. ZSM-11 single crystals were synthesized under hydrothermal conditions, and their crystallization process was monitored by AFM, PXRD, SEM, and SSNMR. SAPO-34 prepared under both HTS and DGC conditions showed morphological differences that are related …

Scanning Electrochemical Microscopy Studies Of Nickel Surfaces And T24 Single Live Cells, Yu Sun

Electronic Thesis and Dissertation Repository

Scanning electrochemical microscopy offers a good insight into nickel surface analysis and human bladder cancer cell studies.

The surface microstructures are related with chemical reactivity by superimposing SECM, SEM and Tof-SIMS images together. Depth scans were exploited for studying chemical reactivity quantitatively by comparison with COMSOL simulation results. Simulation models are described.

Extracellular reactive oxygen species are detected by SECM. Quantitative results were demonstrated by simulation, and concentrations of H₂O₂ and O₂ were acquired. The interaction between cancer cells and vitamin C was investigated. The switch-type behaviour of vitamin C on the PMA-induced ROS burst of …

Migration Behaviour Of Discontinuous Buffers In Capillary Electrophoresis During Protein Enrichment, Ting Li

Electronic Thesis and Dissertation Repository

To enrich protein at sub-microliter sample volumes, our group has developed a discontinuous buffer system which consists of an acid and a base inside a capillary. Upon voltage application, the protein moves towards and stacks at the pH junction. Prior to this work, we only focused on the protein enrichment and have not investigated the migration behaviour of various ions in this system. However, it is important to understand the mechanism of the migration of these ions, because the pH junction formation and further the protein enrichment are based on it. In this work, the ion migration patterns at the …

Scanning Probe Microscopy Studies Of The Properties Of Conducting Polymers, Kevin D. O'Neil

Electronic Thesis and Dissertation Repository

Electronically conducting polymers (ECPs) have been growing in interest as important materials for a variety of different applications such as charge storage devices and photovoltaics. However, in all of these applications, the performance of conducting polymers are strongly dependent upon their local properties such as morphology, local conductivity and carrier mobility, local chemical composition, etc. All polymer materials feature a distribution of these parameters and therefore, they are considered heterogeneous. In this work, we use atomic force microscopy (AFM) and its related techniques such as current-sensing AFM (CS-AFM), Kelvin probe force microscopy (KFM) and phase imaging (PI-AFM) to directly investigate …

Miniaturized Fractionation And Purification Of Analytes Of Interest In Complex Mixtures: Protein Enrichment And Purification With Capillary Electrophoresis And Identification Of Pesticide Chemicals In Bio-Oils, Christina J. Booker

Electronic Thesis and Dissertation Repository

The ability to isolate and detect an analyte of interest is vital for many different facets of life today, from disease detection to environmental safety. The goal of the method development discussed within this thesis is to isolate and identify unique analytes from complex matrices and to do so in a scaled down approach. Removal of an analyte from a diverse background of molecules is often required for successful detection and determination of analyte properties. As well, many samples are only available at low volumes and at trace levels so miniaturized techniques that only require small sample volumes are designed …