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Characterization And Discrimination Of Large Caliber Gun Blast And Flash Signatures, Bryan J. Steward

Theses and Dissertations

Two hundred and one firings of three 152 mm howitzer munitions were observed to characterize firing signatures of a large caliber gun. Muzzle blast expansion was observed with high-speed (1600 Hz) optical imagery. The trajectory of the blast front was well approximated by a modified point-blast model described by constant rate of energy deposition. Visible and near-infrared (450 - 850 nm) spectra of secondary combustion were acquired at 0.75 nm spectral resolution and depict strong contaminant emissions including Li, Na, K, Cu, and Ca. The O2 (X-b) absorption band is evident in the blue wing of the potassium D lines …

Spectroelectrochemistry And Voltammetry Of Metalloporphinones, Florentina Tutunea

Dissertations (1934 -)

Metalloporphinones have been found in a number of enzymes involved in nitrogen metabolism. The emphasis of this research project has been to develop spectroscopic markers in order to identify metal versus porphinone reduction. The carbonyl group in the porphinone has a very strong signal which is quite sensitive to the extent of reduction of the porphinone macrocycle.

The spectral change makes IR an important tool in the process of structure determination of metalloporphyrins because the carbonyl group shift can be correlated with the metal oxidation state. It was observed from previously published studies that a higher metal oxidation state moves …

Measurement Of The Electronic Density Of States Of Graphene Oxide Using Capacitive Photocurrent Spectroscopy., Tanesh Bansal

Electronic Theses and Dissertations

Understanding of the band structure of the new nano materials is essential to have a deeper insight into their optical and electrical properties. Along with the existing techniques used for characterization of nano-materials, it is also important to develop new techniques and methods which can reveal previously unobserved details. This dissertation describes an innovative measurement technique, capacitive photocurrent spectroscopy (CPS), which is used to probe the density of states (DOS) of graphene, graphene oxide (GO) and reduced graphene oxide (rGO). In contrast to the standard photocurrent measurement technique, CPS technique uses a floating electrode (electrodes separated by an insulator) configuration. …

A Model Describing The Effects Of Equipment, Instruction And Director And Student Attributes On Wind-Band Intonation, Brian C. Wuttke

Open Access Dissertations

The purpose of this study was to test a hypothesized model of wind-band intonation, using equipment, instruction and director and student attributes as components. Band directors (N= 5) and their students N= 200) were given a combination of published and researcher designed tests to measure equipment quality, experience, knowledge of instrument pitch tendencies and aural discrimination skills. In addition, each band was video recorded to observe their warm-up, tuning and rehearsal procedures and activities. Spectrum analysis using Praat phonetic analysis software (Boersma & Weenik, 2010) was used to measure wind-band intonation. Structural equation modeling (SEM) using AMOS (Arbuckle, 2008) was …

Characterization Of Composite Broad Band Absorbing Conjugated Polymer Nanoparticles Using Steady-State, Time-Resolve And Single Particle Spectroscopy, Maxwell Scotland Bonner

Electronic Theses and Dissertations

As the global economy searches for reliable, inexpensive and environmentally friendly renewable energy resources, energy conservation by means of photovoltaics has seen near exponential growth in the last decade. Compared to state-of-the-art inorganic solar cells, organic photovoltaics (OPVs) composed of conjugated polymers are particularly interesting because of their processability, flexibility and the potential for large area devices at a reduced fabrication cost. It has been extensively documented that the interchain and intrachain interactions of conjugated polymers complicate the fundamental understanding of the optical and electronic properties in the solid-state (i.e. thin film active layer). These interactions are highly dependent on …

High Pressure And Micro-Spectroscopic Studies Of Single Living Erythrocytes And The Intraerythrocytic Multplication Cycle Of Plasmodium Falciparum, Silki Arora

Electronic Theses and Dissertations

A novel experimental approach for micro-absorption spectroscopy and high-pressure microscopy of single cells is developed and applied to the investigation of morphological, volume, and spectroscopic changes in healthy red blood cells (RBCs) and erythrocytes infected with the malaria parasite Plasmodium falciparum. Through real-time optical imaging of individual erythrocytes (size ~ 7[micrometer]) we determine the change in volume over the pressure range from 0.1 to 210 MPa. The lateral diameter of healthy RBCs decreases reversibly with pressure with an approximate slope of 0.015 [micrometer] / MPa. In infected cells, clear differences in the deformability and between the compression and decompression curves …

Infrared Emission Spectroscopy Of Hot Carbon Monoxide, Farnood Khalilzadeh Rezaie

Electronic Theses and Dissertations

Gas giant exoplanets known as hot Jupiters orbit close to their parent stars and are heated to high temperatures. Their infrared spectra, measured by photometry during secondary eclipses, are dominated by carbon monoxide and methane, the principle reservoirs of carbon on these planets. The relative CO and CH4 abundances inform us about temperature and pressure conditions and also about mixing by global winds driven by intense but asymmetric heating for these tidally locked bodies. Emission spectra collected during secondary eclipses, as the hot Jupiter passes behind its parent star, in principle allows a determination of the CO:CH4 concentration ratio. Since …

Comparison Of Standard Impedance Spectroscopy Response To Aqueous Metal Ions Using Plain Vs. Surface Derivatized Gold Interdigitated Electrodes, Sindhu Yalamanchili

Master's Theses and Doctoral Dissertations

Abstract Recent work has provided evidence that 5-amino-1, 10 –phenanthroline can react with CS2 to anchor on the gold surface of an interdigitated electrode (IDE) through a dithiocarbamate linkage, resulting in significant changes in impedance response in the presence of Cu2+ solutions. However, questions regarding the stability of the primary amine-based dithiocarbamate self-assembled monolayer, reproducibility of the raw impedance and phase angle data, and possible variation of the background response for the gold IDE array in solutions of different metal ions remain an issue. Primary experimental emphasis is on the reproducibility of standard impedance and phase angle data for the …

Calibration Of Alumina-Epoxy Nanocomposites Using Piezospectroscopy For The Development Of Stress-Sensing Adhesives, Amanda L. Stevenson

Electronic Theses and Dissertations

A non-invasive method to quantify the stress distribution in polymer-based materials is presented through the piezospectroscopic calibration of alumina-epoxy nanocomposites. Three different alumina volume fraction nanocomposites were created and loaded under uniaxial compression in order to determine the relationship between applied stress and the frequency shift of the R-lines produced by alumina under excitation. Quantitative values for six piezospectroscopic coefficients were obtained which represent the stress-sensing property of the nanocomposites. The results were applied to an alumina-filled adhesive in a single lap shear configuration demonstrating the capability of the technique to monitor R-line peak positions with high spatial resolution and …

Investigations On Morphology, Spectroscopy And Near-Infrared Photoresponse Sensitization Of Conjugated Polymers In Organic Photovoltaics, Zhongjian Hu

Electronic Theses and Dissertations

Conjugated polymer architecture and morphology are two of the key factors that determine corresponding opto-electronic device performance. It is well-known that conjugated polymers display a variety of conformations and exhibit aggregation in their materials and even for individual polymer chains. The intrinsic structural heterogeneity of conjugated polymers strongly complicates the active layer morphology and phase separation, which are crucial for photoinduced charge generation and transport in polymer based bulk heterojunction-organic photovoltaics device (BHJ-OPVs). Aiming to probe the molecular level correlations between conjugated polymer architecture, morphology and optoelectronic properties, single molecule spectroscopy (SMS) and single particle spectroscopy (SPS) were employed. The …