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Theses/Dissertations

Spectroscopy

2020

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Full-Text Articles in Physical Sciences and Mathematics

Utilization Of Raman Spectroscopic Techniques For Forensic Science Applications, Alyssa Rose Daniel Dec 2020

Utilization Of Raman Spectroscopic Techniques For Forensic Science Applications, Alyssa Rose Daniel

Masters Theses

In the field of forensic science, it is important to have reliable, accurate, and nondestructive testing methods for evidence collection and testing. Current methods, such as gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC), are destructive to evidence and require lengthy sample preparation. Because of its nondestructive nature, specificity, and portability, Raman spectroscopy has been increasingly improving forensic science. The goal of this work is to expand on the growing pool of knowledge of forensics related Raman applications.

One problem that has plagued forensic scientists for years is how to accurately identify the time since death, or post-mortem interval. …


Second Harmonic Generation Spectroscopy And Microscopy Of Liposomes, Nanoparticles, And Cells, Prakash Hamal Aug 2020

Second Harmonic Generation Spectroscopy And Microscopy Of Liposomes, Nanoparticles, And Cells, Prakash Hamal

LSU Doctoral Dissertations

Second harmonic generation (SHG) is used to investigate the factors that impact nanoparticle-based drug-delivery applications. In the first study, molecular adsorption and transport kinetics of a positively-charged dye, malachite green isothiocyanate (MGITC), is characterized at the surface of different colloidal liposomes in water using SHG spectroscopy. The molecular interactions of MGITC is compared to our previous investigations with malachite green (MG). In comparison to MG, MGITC demonstrates stronger adsorption and faster transport through lipid membranes. Correspondingly, the SHG experimental results are in excellent agreement with the molecular dynamics (MD) simulations results. A key finding illustrates the importance of functional groups, …


An Improved Method For Spectroscopic Quality Classification, Elizabeth G. Mayer Jul 2020

An Improved Method For Spectroscopic Quality Classification, Elizabeth G. Mayer

Mathematics & Statistics ETDs

Spectral quality classification is a vital step in data cleaning before the

analysis of magnetic resonance spectroscopy (MRS) data can be done. This

analysis compares five methods of quality classification; three of these are

legacy methods, Maudsley et al. (2006), Zhang et al. (2018), and

Bustillo et al. (2020), and two newly created methods that used a random forests

classifier (RFC) to inform their classifications. We found that the random forest

classifier was the most accurate at predicting spectra quality (balanced

accuracy for RF of 88% vs legacy of 70%, 72%, or 72%). A

Random-Forests-Informed Filtering method (RFIFM) for quality …


The Primary Volatile Composition Of Comet C/2015 Er61 (Panstarrs), Aaron Butler May 2020

The Primary Volatile Composition Of Comet C/2015 Er61 (Panstarrs), Aaron Butler

Theses

In the outer edges of the solar system exist two regions: the Kuiper belt and Oort cloud. These two regions have a high amount of icy bodies (comets) orbiting the Sun. Comets located within the Oort cloud and Kuiper belt contain an ancient codex to the solar systems contents, before the formation of our solar system. Presented are near-infrared, high-resolution (λ/Δλ ~40000) data obtained from the immersion-grating echelle spectrograph iSHELL at the 3m NASA Infrared Telescope Facility (IRTF) in Maunakea, Hawaii of the Oort cloud comet C/2015 ER61 (PANSTARRS). Observations took place on April 15 and 17 in 2017 while …


Surface-Enhanced Raman Spectroscopy For Cocaine Detection, Kiersten Jo Mead May 2020

Surface-Enhanced Raman Spectroscopy For Cocaine Detection, Kiersten Jo Mead

Chemistry

The detection of drugs of abuse using Raman spectroscopy is of particular interest to forensic researchers at the moment. Raman spectroscopy is highly specific, fast, non-destructive, and can be adapted for in-situ measurements, making it the ideal forensic technique. Researchers working under the guidance of Doctor Igor Lednev have been able to use UV resonance Raman spectroscopy to detect cocaine in oral fluid without the need for sample pretreatment. They were however unable to detect the cocaine at forensically relevant levels. To overcome this limitation, surface-enhanced Raman spectroscopy (SERS) was used in this proof of concept study for the detection …


Trend Analyses Of The Abundances Of Atmospheric Molecules, Anton Fernando Apr 2020

Trend Analyses Of The Abundances Of Atmospheric Molecules, Anton Fernando

Physics Theses & Dissertations

A new line list for the A3Π - X3Σ- electronic transition of NH has been prepared using line positions from the literature and calculated line intensities. High level ab initio calculations were performed with the MOLPRO program to obtain the A - X transition dipole moment function. Potential energy curves and line strengths were calculated with Le Roy's RKR1 and LEVEL programs. Line intensities and Einstein A values were calculated with Western's PGOPHER program after converting the Hund's case (b) output of LEVEL to Hund's case (a) input needed for PGOPHER. The Herman- Wallis effect is …


Mult-Spectral Imaging Of Vegetation With A Diffractive Plenoptic Camera, Tristan R. Naranjo Mar 2020

Mult-Spectral Imaging Of Vegetation With A Diffractive Plenoptic Camera, Tristan R. Naranjo

Theses and Dissertations

Snapshot multi-spectral sensors allow for object detection based on its spectrum for remote sensing applications in air or space. By making these types of sensors more compact and lightweight, it allows drones to dwell longer on targets or the reduction of transport costs for satellites. To address this need, I designed and built a diffractive plenoptic camera (DPC) which utilized a Fresnel zone plate and a light field camera in order to detect vegetation via a normalized difference vegetation index (NDVI). This thesis derives design equations by relating DPC system parameters to its expected performance and evaluates its multi-spectral performance. …


Comparative Experimental And Theoretical Study Of Dopamine And Serotonin Interaction, Jose A. Guerrero Jan 2020

Comparative Experimental And Theoretical Study Of Dopamine And Serotonin Interaction, Jose A. Guerrero

Open Access Theses & Dissertations

To accurately identify and measure the concentrations of dopamine (DA) and serotonin (5-HT) in mixtures of these neurotransmitters without labeling, a comprehensive, comparative computational and Raman experimental analysis is provided. While the distinction between these two analytes may be accomplished for concentrations in the millimolar range of these mixtures, their accurate quantification remains unattainable. As shown for the first time in this study, potential creation of a new composite resulting from their interactions with each other could be a reason for this lack of quantification.

Although this new hydrogen-bonded complex greatly complicates future analyte differentiation and quantification at concentrations typical …


Effects Of Nutrient Overload And Environmental Conditions On Algal Bloom Formation: A Case Study Of Water Sources In Eastern Kentucky, Lauren Sutton Jan 2020

Effects Of Nutrient Overload And Environmental Conditions On Algal Bloom Formation: A Case Study Of Water Sources In Eastern Kentucky, Lauren Sutton

Online Theses and Dissertations

Eastern Kentucky is home to many private ponds used for agricultural and recreational purposes. Each year, the owners of these ponds observe harmful algal blooms (HABs) that release toxins into the water, potentially limiting the use of these ponds. A pilot study in summer 2018 observed a harmful algal bloom (HAB) occurring in one pond in Madison Country that roughly correlated with a rise in water sulfate levels with no detectable levels of nitrate or phosphate present. A follow-up study of this pond and others in the area was conducted during Summer 2019. The purpose of this project was three-fold: …


Investigating The Time Scales Of Electromechanical Motion In Graphene Drumheads Using Pump-Probe Spectroscopy With Stm, Alana P. Gudinas Jan 2020

Investigating The Time Scales Of Electromechanical Motion In Graphene Drumheads Using Pump-Probe Spectroscopy With Stm, Alana P. Gudinas

Honors Theses and Capstones

Scanning tunneling microscopy (STM) has transformed the field of condensed matter physics over the past few decades, allowing scientists to image materials at the atmomic scale, manipulate individual atoms, and probe electronic states on the surface of materials. In recent years, there have been numerous developments to introduce time-resolved measurements to STM in order to probe atomic-scale dynamic processes and combine spatial and temporal resolution. Advances like THz-STM setups achieve femtosecond resolution, but require complex external setups. All-electronic pump-probe spectroscopy for STM (directly analogous to optical pump-probe spectroscopy) has been pioneered by Loth et al., and newer applications (Natterer et …


Using Multispectral Imagery To Interrogate Deposition, Alteration, And Weathering Across Curiosity Rover’S Traverse In Gale Crater, Mars, Christina Seeger Jan 2020

Using Multispectral Imagery To Interrogate Deposition, Alteration, And Weathering Across Curiosity Rover’S Traverse In Gale Crater, Mars, Christina Seeger

WWU Graduate School Collection

Since landing in 2012, the Mars Science Laboratory (MSL) Curiosity rover has explored over 20 kilometers of Gale crater, climbing almost 400 meters in elevation. The fluvio-deltaic, lacustrine, and aeolian sediments in the crater have been well documented by Curiosity’s suite of in situ and remote science instruments. Indeed, they have traced chemical trends that track changes in lithology and diagenesis over the study area—though most instruments only sample individual rock, vein, and soil targets at a very small scale. The Mast Camera (Mastcam) has periodically acquired much larger (meter-scale) multispectral, visible to near-infrared observations of outcrops throughout this stratigraphic …


Synthesis Of Graphene Using Plasma Etching And Atmospheric Pressure Annealing: Process And Sensor Development, Andrew Robert Graves Jan 2020

Synthesis Of Graphene Using Plasma Etching And Atmospheric Pressure Annealing: Process And Sensor Development, Andrew Robert Graves

Graduate Theses, Dissertations, and Problem Reports

Having been theorized in 1947, it was not until 2004 that graphene was first isolated. In the years since its isolation, graphene has been the subject of intense, world-wide study due to its incredibly diverse array of useful properties. Even though many billions of dollars have been spent on its development, graphene has yet to break out of the laboratory and penetrate mainstream industrial applications markets. This is because graphene faces a ‘grand challenge.’ Simply put, there is currently no method of manufacturing high-quality graphene on the industrial scale. This grand challenge looms particularly large for electronic applications where the …


Bio-Preservation Potential Of Sediment In Eberswalde Crater, Mars, Cory Hughes Jan 2020

Bio-Preservation Potential Of Sediment In Eberswalde Crater, Mars, Cory Hughes

WWU Graduate School Collection

Within Eberswalde crater, Mars, is one of the most well-preserved river delta deposits identified within Mars’ rock record, and visually traceable from the deposit, is the partially-intact watershed that fed the paleo-lake that once resided within the crater basin. Aqueous alteration minerals, smectite clays and opaline silica, have been previously identified within the deposit, however the origin of those minerals is not well understood. Through analysis of topographic and hyperspectral data, we seek to ascertain the origin and provenance of these minerals to better understand their formative conditions and formation age. We will also assess Eberswalde crater’s potential as a …