No / Recent studies relating to the analytical chemical characterization of terrestrial extremophiles reveal the presence of biomolecules that have been synthesized for the survival of the colonies in response to the extreme environmental conditions, where otherwise life could not exist. This is a vital part of the planned space missions now being undertaken to planets and their satellites in the search for extinct or extant life signatures in our Solar System. Extremophiles have existed on the Earth for some 3.8 Gyr and their interrogation indicates their strategic survival methods which can be associated and compared with extraterrestrial scenarios on Mars, Titan, Enceladus and Europa.

No / Fourier transform (FT) Raman spectroscopy was evaluated as a non-destructive analytical tool for assessing the degradative state of archaeological and forensic hair samples. This work follows the successful application of FT-Raman spectroscopy to studies of both modern hair and ancient keratotic biopolymers, such as mummified skin. Fourteen samples of terminal scalp hair from 13 disparate depositional environments were analysed for evidence of structural alteration. Degradative change was evidenced by alteration to the amide I and III modes near 1651 and 1128 cm−1, respectively, and loss of definition to the (CC) skeletal backbone and the impact of environmental contaminants was noted.

No / Spectroscopic techniques have the potential to provide powerful, molecular-specific, non-invasive measurements on polymers during melt processing operations. An exploration is reported of the application and assessment of sensitivity of in-process vibrational spectroscopy¿on-line mid-infrared (MIR), on-line near-infrared (NIR), in-line NIR and in-line Raman¿for monitoring of single screw extrusion of high-density polyethylene and polypropylene blends. These vibrational spectroscopic techniques are compared with novel in-line ultrasound velocity measurements, which were acquired simultaneously, to assess the sensitivity of each method to changes in blend composition and to explore the suitability for their use in real time process monitoring and control.

Raman and/or infrared (IR) bandshape analysis to probe molecular dynamics in liquids has become a rapidly expanding field of study in recent years. Determination of spinning and tumbling diffusion constants, Dι and D⊥, which characterize the reorientation of symmetric-top moleclues has been successfully studied in a number of D6H and D3H molecules. For molecules of CV3 symmetry, however, previous attempts to extract spinning diffusion constants from Raman doubly degenerate vibrations (E mode) have proved unsuccessful. Presented here is a new methodology which resolves the problems encountered by former researchers through calculation of Dι utilizing the narrower Lorentzian component of E vibrations.

Solid oxide fuel cells (SOFCs) represent a much cleaner and more efficient method for harnessing fossil fuel energy than conventional combustion; however, the challenge with making SOFCs mainstream lies in reducing operating costs and staving off their rapid degradation. High cathode polarization remains a bottleneck for lowering operation temperature. On the anode side, supplying SOFCs with hydrocarbon-based fuels poses many problems for systems using state-of-the-art material specifications such as composites of Ni and yttria-stabilized zirconia (YSZ). Various novel materials and surface modifications have been found to mitigate these problems, but more information towards a more profound understanding the role of these materials is desired. In this work, advanced Raman spectroscopic techniques were applied toward this end. Raman spectroscopy was used for the tracking of the evolution of water, carbon, sulfur, and oxygen species as well as new phases at SOFC electrode surfaces following or during exposure to various temperatures, atmospheres, and electrochemical stimuli. This information, coupled with performance data and other characterizations, would help to clarify the mechanisms of anode contamination reactions and oxygen reduction reactions. Knowledge gained from this work would also help to connect electrode modifications with performance enhancement and poisoning tolerance, offering insights vital to design of better electrodes. In addition, lack of adequate Raman signal from certain species, which is one of Raman spectroscopy’s limitations, was addressed. Surface enhanced Raman scattering (SERS) techniques were used in both in situ and ex situ analyses to increase signal yield from gas species and phases that are found only in trace amounts on electrode surfaces. Finally, a more practical thrust of this work was the application of this study methodology and the knowledge gained from it to cells with NASA's bielectrode supported cell (BSC) architecture. These types of cells also offer great prospects for superior specific power density due to their low weight. Ultimately, the goal of this thrust was progress towards achieving optimum performance of SOFCs operating under hydrocarbon fuels.

This thesis presents a light scattering-based method for biomarker detection, which could potentially be used for the quantification of multiple biomarkers specific to B-cell malignancies. This method uses fabricated gold nanoparticle probes to amplify inelastic light scattering in a process referred to as surface-enhanced Raman scattering. These gold nanoparticle probes were conjugated to antibodies for specific and targeted molecular binding. The spectrum of the amplified inelastic light scattering was detected using a spectrometer and a detector. To detect the light scattering signal from the gold nanoparticle probes, several commercial Raman spectrometer instruments were evaluated. Initial results from these evaluations are presented in this thesis. After system evaluation, a custom Raman microscope system was designed, built, and tested. This system was used for the development of a surface-enhanced Raman spectroscopy-based immunoassay. The development of this assay confirms the successful design of gold nanoparticle probes for the specific targeting and detection of immunoglobulins. The immunoassay also shows promise for the simultaneous detection of multiple biomarkers specific to B-cell malignancies.

Current micro-scale electronics technology has been approaching rapidly towards its technological limit. This has shifted the focus towards nano-scale technology in recent years. More and more researchers around the globe are working in pursuit of bringing nano-scale technology into mainstream. The research carried out here is a small step towards a similar goal. The remarkable optical properties exhibited by certain nano-scale structures are in stark contrast to their bulk form and this provides the basis for this research. Two kinds of nanostructures are developed and investigated for their optical properties. One of these is nanofibers processed from a polymer known as polyaniline (PANI). The focus of this study is to investigate its optical and conductive properties under different conditions of doping environments, temperature and polymerization conditions. Optical characterization technique such as UV-Visible spectroscopy is developed to carry out the investigation. The developed nanofibers have been demonstrated to possess optical and conductive properties to be dependent on doping variables. Study of these optical properties could prove very useful in the development of electrochromic devices and gas sensors. Later in the research, UV-Visible spectroscopy has been improved into a low cost Raman spectroscopy setup which is validated by experimentation carried out on some samples. The second type of nano-structure developed and investigated, is an array of nanoparticles of noble metals such as gold and silver. Such an array is shown to exhibit a phenomenon called plasmon resonance effect when excited by light. UV-Visible spectroscopy technique is utilized to investigate this effect for metal nano-arrays. A biologically nano-structured surface (wing of an insect called cicada) is used as the substrate for the fabrication of metal array. A serious attempt has also been made to do 'Surface Enhanced Raman Spectroscopy (SERS)', making use of the metal nano-array developed. This technique improves the raman lines intensities of certain less sensitive samples such as thiophenol, which are known to give weak raman lines. This is carried out by adsorbing the sample on the metal nano-array.

The development of microscale and nanoscale devices has outpaced the development of metrology tools necessary for their complete characterization. In the area of thermal MEMS technology, accurate measurements across a broad range of temperatures with high spatial resolution are not trivial. Thermal MEMS are devices in which the control and manipulation of temperature is necessary to perform a desired function, and are used in actuation, chemical sensing, nanolithography, thermal data storage, biological reactions and power generation. In order to properly design for reliability and performance issues amongst these devices and verify modeling accuracy, the temperature distribution under device operating conditions must be experimentally determined. Raman spectroscopy provides absolute temperature measurements with spatial scales below 1 micron, which is sufficient for most MEMS devices. In this work, a detailed study of Raman spectroscopy as an optical thermal metrology tool was performed. It is shown that a calibration of the Stokes shift with temperature yields a linear calibration for measurements up to 1000?n polysilicon. These coefficients were determined for polysilicon processed under various conditions (575-620?B and P doping) to assess the effects of microstructural variations on Raman spectra. The Stokes peak was also shown to shift linearly with an applied pure bending stress. In order to make stress-independent thermometry measurements, the ratio of the Stokes to anti-Stokes signal intensities and the Stokes linewidth were calibrated over the same temperature range. Using the calibration data, Raman spectroscopy was implemented for the evaluation of temperature of thermal MEMS. Heated AFM cantilevers and micro-beam heaters were chosen due to their wide range of applications. Different thermal and mechanical boundary conditions were considered by studying both the beams and cantilevers, resulting in varying levels of thermal stress. By using the three calibrations in a complementary fashion, the validity of Raman thermometry was explored. Device temperatures of up to 650?nd their corresponding uncertainties were found, and used to verify FEA modeling. Effects of thermally induced stresses were taken into account and analyzed. Possible uncertainties such as laser heating, spatial and spectral resolution, light collection efficiency, measurement uncertainty, and instrumental drift were reported and elucidated.

This thesis explores the use of Raman Spectroscopy to study the battery cathode material LiFePO4. Surface Enhanced Raman Spectroscopy (SERS) was incorporated into the study due to fluorescence that traditionally plagues Raman. By imaging LiFePO4 nanoparticles, an understanding can be gained of the complex chemistry taking place when the material is lithiated and delithiated at the nanoscale level and the phase changes of the material that occur during this process. The use of bimetallic (Au/Ag) SERS substrates allowed for more stable substrates with longer shelf life compared single metal Ag substrates. Further tuning of these substrates can be applied to the ever evolving science of energy storage material technology as a way to track phase changes in the material. / text

The goal of current solid oxide fuel cell (SOFC) research is to design electrode materials and other system components that permit the fuel cell to be operated in the 400-700ºC range. Cell performance in this lower temperature range is limited by the oxygen reduction process at the SOFC cathode and by multiple contamination processes. The work presented demonstrates that Raman spectroscopy, a form of vibrational spectroscopy, can provide structural and compositional information complementary to that from traditional characterization methods. Initial experiments into the oxygen reduction mechanism on SOFC cathodes were unable to detect surface oxygen species on selected perovksite-based SOFC cathode materials. However, the Raman signal from the cathode surface was able to be enhanced by depositing silver or gold nanoparticles on the cathode, creating the so-called surface-enhanced Raman scattering (SERS) effect. The Raman sample chamber was also used to study two possible electrode contamination processes. First, the deposition of carbon on nickel and copper anodes was observed when exposed to different hydrocarbon fuel gases. Second, the poisoning of an SOFC cathode by chromium-containing vapor (usually generated by stainless steel SOFC system components) was monitored. Overall, Raman spectroscopy was shown to be useful in many areas crucial to the development of practical, cost-effective SOFCs. The techniques developed here could also be applied to other high temperature electrochemical and catalytic systems.