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Communiplaytion: Getting Our Hands Dirty Together, Brooke Tyson Cassady
Communiplaytion: Getting Our Hands Dirty Together, Brooke Tyson Cassady
LSU Master's Theses
CommuniPLAYtion: getting our hands dirty together is a weeklong installation of a collective ceramics studio implanted in Foster Gallery. It is a participatory and interactive exhibition that demonstrates how material play creates moments for personal reflection and contemplation, while also facilitating communication and social relations within a specific place. CommuniPLAYtion is an opportunity for an altruistic exchange among individuals in contrast to the monetary transactions that momentarily connect strangers. These engagements, similar to the “Do-It-Yourself Geopolitics” of other contemporary artists, empower individuals to develop modes of interaction that suit their interpersonal needs. The exhibition, communiPLAYtion enables the basic precursors that …
Subthreshold Photoionization In Molecular Dopant/Perturber Systems., Cherice Marie Evans
Subthreshold Photoionization In Molecular Dopant/Perturber Systems., Cherice Marie Evans
LSU Historical Dissertations and Theses
The use of atomic and molecular Rydberg states to investigate dopant/perturber interactions is a well established research area. In this Dissertation, photoionization spectroscopy is used to probe the interactions between various dopants (D = CH3I, C2H5I and C6H6) and perturbers (P = Ar, N2, CO2, CF4, c-C4F8 and SF6) in a static gas-phase system. One overall goal is a better understanding of the nature of dopant/perturber interactions in the gas phase which, in turn, can lead to a better understanding of solvation in the condensed phase. Two separate perturber effects are investigated in this work: the perturber-induced energy shift of …
X -Ray Absorption Fine Structure (Exafs And Xanes) And Microscopic Investigations Of Supramolecular Systems., Pierre Nicolas Floriano
X -Ray Absorption Fine Structure (Exafs And Xanes) And Microscopic Investigations Of Supramolecular Systems., Pierre Nicolas Floriano
LSU Historical Dissertations and Theses
Self-assembled monolayers of n-alkanethiols, CH3-(CH 2)x-SH, on Au, Ag, and Cu have been studied with Grazing incidence EXAFS (GIXAFS) at the sulfur K-edge. Characterization of the bonding of self-assembled monolayers is of great interest because of their ability to tailor physical and chemical properties of surfaces. For both pentanethiol and decanethiol monolayers on Ag and Cu, the three-fold hollow site is found to be the most probable sulfur binding site. However, observations for octadecanethiol indicate that the three-fold-hollow site is not the exclusive binding site. In addition, the possible existence of disulfide bonds on the metal surface (adsorbed dialkyldisulfides) is …
Picosecond Resonance Raman Studies Of Interligand Electron Transfer Rates Of Ruthenium Polypyridal Complexes., Danny Ray Anderson
Picosecond Resonance Raman Studies Of Interligand Electron Transfer Rates Of Ruthenium Polypyridal Complexes., Danny Ray Anderson
LSU Historical Dissertations and Theses
Interest in ruthenium polypyridal complexes stems from the metal-to-ligand charge transfer state (MLCT) that can be generated by photons of sufficient energy and the interligand electron transfer (ILET) that occurs after this state. Direct measurements using picosecond resonance Raman spectroscopy were made to determine the rates of ILET in a series of mixed ligand ruthenium polypyridal complexes. To perform these studies, a novel regenerative amplified Nd:YAG laser system had to be designed and built at Louisiana State University. Once this system was completed, a apparatus was designed for measuring transient absorption spectra in the 200--300 nm wavelength range on a …
Photoionization Studies Of Intramolecular Dynamics: A Closer Look., Chuanyong Wu
Photoionization Studies Of Intramolecular Dynamics: A Closer Look., Chuanyong Wu
LSU Historical Dissertations and Theses
Using synchrotron radiation as an excitation source, dispersed fluorescence measurements of two different molecular systems are presented in this dissertation with the intention to study the two fundamental aspects of shape resonances-complexity and completeness. $\rm C\sb6F\sb6$ is a relative large and complex molecule in the sense that nonradiative transitions can take place unimolecularly in the free species. The elucidation of the ionization dynamics of this molecule helps to bridge the gap from simple molecules to matter in condensed phases. In the $\rm 2a\sb{2u}\sp{-1}$ photoionization study of $\rm C\sb6F\sb6,$ the non-Franck-Condon behavior of the vibrational distributions at around 20 eV indicates …
The Selective Digital Integrator: A New Device For Modulated Polarization Spectroscopy., Aljosa Vrancic
The Selective Digital Integrator: A New Device For Modulated Polarization Spectroscopy., Aljosa Vrancic
LSU Historical Dissertations and Theses
A new device, a selective digital integrator (SDI), for the acquisition of modulated polarization spectroscopy (MPS) signals is described. Special attention is given to the accurate measurement of very small (AC component of interest $<$10$\sp{-3}$ x DC component), rapidly modulated ($\sim$50 kHz) signals at or below noise levels. Various data acquisition methods and problems associated with the collection of modulated signals are discussed. The SDI solves most of these problems and has the following advantages: it provides the average-time resolved profile of a modulated signal; it eliminates errors if the modulation is not sinusoidal; it enables separate measurements of the various phases of the signal modulation cycle; it permits simultaneous measurement of absorption, circular dichroism (CD) and linear dichroism (LD) spectra; it facilitates 3-D absorbance measurements; it has a wide gain-switching-free dynamic range (10 orders of magnitude or more); it offers a constant S/N ratio mode of operation; it eliminates the need for photomultiplier voltage feedback, and it has faster scanning speeds. The time-resolution, selectivity, wide dynamic range, and low-overhead on-the-fly data processing are useful for other modulated spectroscopy (MS) and non-MS experiments such as pulse height distribution and time-resolved pulse counting measurements. The advantages of the MPS-SDI method are tested on the first Rydberg electronic transitions of (+)-3-methylcyclopentanone. The experimental results validate the predicted SDI capabilities. However, they also point to two difficulties that had not been noted previously: the presence of LD in a gaseous sample and a pressure-dependence of the relative peak heights of the CD spectrum. Models for these anomalies are proposed. The presence of the oscillatory LD (but not an LD background) is explained with a sample cell model based on the observed polarization-dependent time-resolved profiles of transmitted light intensity. To obtain expressions for these intensities, a theoretical background, which provides a new approach to the treatment of light/matter interaction, is included as an Appendix. To explain the second anomaly, present only at high optical densities, a model based on the presence of scattered light is introduced and verified. The mode of correction for the scattering problem is outlined.
Ultrafast Studies Of Reaction Dynamics., Zhenguo Feng
Ultrafast Studies Of Reaction Dynamics., Zhenguo Feng
LSU Historical Dissertations and Theses
The long range goal of this research is to understand the role of the solvent in condensed phase reactions. In the gas phase, great strides have been made towards understanding chemical reactivity at the level of individual quantum states. Liquid state reactions are not as well understood due to complicated many-body interactions with the solvent. Our approach has been to study simple reactions in solvents near their critical state. Here a small change in pressure, at constant temperature, allows a continuous change in solvent bulk density and viscosity, from near-liquid to gas-like properties. In this way reactions can be studied …
Concurrent Vs. Terminal Augmented Feedback In The Learning Of A Discrete Bimanual Coordination Task., Cynthia Marie Hadden
Concurrent Vs. Terminal Augmented Feedback In The Learning Of A Discrete Bimanual Coordination Task., Cynthia Marie Hadden
LSU Historical Dissertations and Theses
Two experiments compared the effects of concurrent and terminal augmented feedback in learning a bimanual coordination task. In the first experiment, twenty-four participants practiced a discrete bimanual task that required a 90$\sp\circ$ phase offset of the upper limbs under one of two feedback conditions: concurrent or terminal. Participants in the concurrent feedback group received feedback as they performed the task during acquisition. Participants in the terminal feedback group received feedback after they completed each acquisition trial. Results indicated that concurrent group was able to more accurately produce the target figure during acquisition than the terminal group. Unlike earlier studies which …
Solid State Energy Barriers To Olefin Ligand Rotation Of Rhodium Compounds And Single Crystal X-Ray Structure Determination Of Synthetic And Natural Products., Yen-Hsiang Liu
LSU Historical Dissertations and Theses
Atomic displacement parameters (ADPs) were derived from X-Ray diffraction data collected at two different temperatures (294K and 115K) from a single crystal of Rh(acac)(C$\rm\sb2H\sb4)\sb2.$ Since the thermal ellipsoids of atoms in the one crystallographically independent ethylene group displayed distinctive elongation normal to the C=C bond, a TLS rigid body analysis of the $\rm C\sb2H\sb4$ ligand rotation was undertaken. Using a locally modified version of Trueblood's THMA14 computer program, it was found that at 115K the root-mean-square amplitude of libration normal to the Rh-(CC centroid) axis is $7(4)\sp\circ,$ while at 294K it is $10(6)\sp\circ$ (estimated standard deviations in parentheses). The rotational …
Synthesis, Molecular Characterization And Physical Behavior Of Novel Polymers And Polymer Blends: Poly(Aryl Ether)Sulfones, Labeled Poly(Gamma-Stearyl-Alpha, L-Glutamate) And Poly(Gamma-Stearyl-Alpha, L-Glutamate)/Polyethylene Blends., Frederick Harald Roos
LSU Historical Dissertations and Theses
The structures of a number of novel poly(aryl ether) sulfones (nitro, aminomethyl, methyl and ethyl derivatives), which have applications as separation membranes, were determined unequivocally for the first time by applying sophisticated two-dimensional nuclear magnetic resonance (NMR) methods. The degree of substitution (DS) was found to vary among the products from 0.1 percent to about 2 percent (DS: nitro, 2.0; amino, 0.11; aminomethyl, 0.76; methyl, 2.12; ethyl, 2.05). Poly($\gamma$-stearyl-$\alpha$,L-glutamate), PSLG, is a "fuzzy rod" polymer composed of a central backbone that can exist as an $\alpha$-helix. This backbone, a polypeptide, is hydrophilic. The stearyl side chains (the "fuzzy" part of …
Fluorescence Polarization Studies: A Global View Of Molecular Photoionization Dynamics Over An Extended Energy Range., Romith Ranjan Das
Fluorescence Polarization Studies: A Global View Of Molecular Photoionization Dynamics Over An Extended Energy Range., Romith Ranjan Das
LSU Historical Dissertations and Theses
The experimental technique of measuring the degree of polarization of the fluorescence from electronically excited molecular ions is used to determine the alignment of N$\sb2$, CO and N$\sb2$O photoions over an extended range of excitation energy. The polarization of $\rm CO\sp+(B\sp2\Sigma\sp+\to\ X\sp2\Sigma\sp+),\ N\sb2\sp+(B\sp2\Sigma\sb{u}\sp+\ \to \ X\sp2\Sigma\sb{g}\sp+)$, and $\rm N\sb2O\sp+\ (A\sp2\Sigma\sp+\ \to\ X\sp2\Pi)$ fluorescence over a 200 eV photon energy range is used to interpret the oscillator strength distributions for normally unresolved degenerate ionization channels. The results show the influence of a CO $4\sigma\to k\sigma$ shape resonance clearly, and agreement between theory and experiment is excellent. The N$\sb2$O experimental results indicate …
Mechanism Of Nitrogen Fixation: Use Of Carbon Monoxide To Probe Nitrogenase Activity., Linda Margaret Cameron
Mechanism Of Nitrogen Fixation: Use Of Carbon Monoxide To Probe Nitrogenase Activity., Linda Margaret Cameron
LSU Historical Dissertations and Theses
The inhibitor CO was used to investigate the mechanism of Mo and V nitrogenase. While low pressures of CO enhanced, high pressures inhibited V nitrogenase-catalyzed C$\rm\sb2H\sb6$ formation. This is not the case for $\rm C\sb2H\sb4$ formation, where the rate of electron flux determined if CO acted as an enhancer or inhibitor. A two-site model is proposed, in which CO binding to one site enhances, and CO binding to both sites inhibits product formation. Replacement of CO(g) by Ar or $\rm C\sb2H\sb2$ resulted in correlated decay of hi-CO and development of lo-CO EPR signals, suggesting that the two signals arise from …
Development Of A Femtosecond Time-Resolved Raman Spectrometer For Hemoglobin Studies., Junbo Chen
Development Of A Femtosecond Time-Resolved Raman Spectrometer For Hemoglobin Studies., Junbo Chen
LSU Historical Dissertations and Theses
A femtosecond time-resolved Raman spectrometer is developed to study the ultrafast dynamics of hemoprotein. The laser system consists of a dye laser synchronously pumped by the SHG of compressed ML Nd:YAG laser pulse, and a Ti:sapphire regenerative amplifier using chirped-pulse-amplification technique. The laser system provides 350 fs pulses output with 0.4 mJ/pulse energy at the repetition rate of 1 kHz. The tunability covers the whole Ti:sapphire lasing range with the use of different laser dye. Femtosecond time-resolved resonance Raman experiment shows that the ligand photodissociation quantum yield depends on the nature of ligand. With three ligands studied, CO has about …
Studies Of V-Nitrogenase From Azotobacter Vinelandii: Structural Variations, Temperature And Solvent Effects., Carol Zembiak Blanchard
Studies Of V-Nitrogenase From Azotobacter Vinelandii: Structural Variations, Temperature And Solvent Effects., Carol Zembiak Blanchard
LSU Historical Dissertations and Theses
When Q-Sepharose was used in the purification of the V-nitrogenase proteins from Azotobacter vinelandii, an increase in resolution was observed which resulted in a separation of the nitrogenase component 1 protein (Av1$\sp\prime$) into two forms, labeled Av1$\sp\prime\sb{\rm A}$ and Av1$\sp\prime\sb{\rm B}.$ Even though both forms possessed the same enzymatic behavior, Av1$\sp\prime\sb{\rm A}$ exhibited a lower specific activity and migrated during gel filtration with an apparent lower molecular weight than Av1$\sp\prime\sb{\rm B}.$ Furthermore, SDS-polyacrylamide gel electrophoresis showed different relative compositions of the two major subunits of both forms with Av1$\sp\prime\sb{\rm A}$ possessing a trimer $(\alpha\beta\sb2)$ pattern compared to the tetramer $(\alpha\sb\beta\sb2)$ …
The Relationship Between The Accuracy Of Certain "Generalized" Body Density Prediction Equations And Indices Of Fatness, Body Physique/Proportionality And Fat Distribution., Christopher Melancon Hearon
The Relationship Between The Accuracy Of Certain "Generalized" Body Density Prediction Equations And Indices Of Fatness, Body Physique/Proportionality And Fat Distribution., Christopher Melancon Hearon
LSU Historical Dissertations and Theses
There is a need to eliminate the least accurate of the existing equations for anthropometrical body density prediction and support for the use of specific prediction equations over generalized equations. The purpose of the investigation was to examine the accuracy of the Jackson-Pollock (JP) and Durnin-Womersley (DW) generalized anthropometrical body density prediction equations in relation to indices of overall fatness, regional fat distribution and body proportionality. The relationships between prediction accuracy (predicted body density minus hydrodensitometric estimate of body density) and three mass/stature indices (total fatness indices), waist-to-hip circumference ratio (WC/HC)(android/gynoid fat distribution) and the three components of the Heath-Carter …
Solution Behavior Of Cascade Polymers., Keunok Han Yu
Solution Behavior Of Cascade Polymers., Keunok Han Yu
LSU Historical Dissertations and Theses
This thesis consists of four chapters. In the first, a general introduction is presented. Chapter 2 deals with the characterization of polyamidoamine (PAMAM) cascade polymers. Diffusion coefficients of four different generations (generation 3, 5, 7, and 9) of PAMAMs were measured in aqueous solutions by dynamic light scattering. Generation 3 and 5 were characterized again, after labeling with fluorescein isothiocyanate, by fluorescence photobleaching recovery. The dynamic light scattering results depended on the concentration of added salt in the low salt limit, while the fluorescence values were almost independent of salt concentration. The polyelectrolyte effects, or solution nonidealities, strongly affected light …
X-Ray Absorption And Electron Paramagnetic Resonance Studies Of Azotobacter Vinelandii Nitrogenase., Roland Carroll Tittsworth
X-Ray Absorption And Electron Paramagnetic Resonance Studies Of Azotobacter Vinelandii Nitrogenase., Roland Carroll Tittsworth
LSU Historical Dissertations and Theses
Fe K-edge Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy was used to investigate the metal-cluster structure of both the Mo-containing (Av1) and V-containing (Av1$\sp\prime$) nitrogenase component 1 proteins of Azotobacter vinelandii in their as-isolated and thionine-oxidized states. Using the EXAFS data, plausible distance assignments were made for the cofactor clusters. It was shown that small but consistent distance changes occur in both Av1 and Av1$\sp\prime$ upon thionine oxidation. Furthermore, the EXAFS of Av1$\sp\prime$ is very similar to that of Av1, supporting the proposal that the two proteins have homologous metal cluster structures. Fe K-edge and Mo K-edge EXAFS were used …
Theoretical Studies Of Sodium Metal Clusters., Melissa R. Prince
Theoretical Studies Of Sodium Metal Clusters., Melissa R. Prince
LSU Historical Dissertations and Theses
Theoretical methods were used to study small sodium metal clusters. The goal was to find a simple way to model the electronic structure in these clusters that can be used to study large sodium clusters. Monte Carlo studies using Feynman's path integral formulation of quantum mechanics with Bose-Einstein statistics were used to study sodium metal clusters whose valence electrons with opposite spins were paired as bosons. Next, non-atom-based Gaussian s orbitals were used in a Hartree-Fock Monte Carlo procedure. Based on these results, standard quantum chemistry programs were used to test the utility of using non-atom-based basis sets made up …
The Relationship Between Intrinsic And Augmented Feedback In Motor Skill Learning., David Ian Anderson
The Relationship Between Intrinsic And Augmented Feedback In Motor Skill Learning., David Ian Anderson
LSU Historical Dissertations and Theses
Four experiments examined the influence of knowledge of results (KR) schedule and the characteristics of intrinsic feedback on the acquisition and retention of a simple motor task. In the first experiment, subjects practiced a one-dimensional aiming movement and were provided with KR either directly after each trial or after a delay of two trials. The results showed that subjects who received KR after a delay of two trials were less accurate in acquisition but more accurate in retention than subjects who received KR directly after each trial. These results were replicated in a second experiment using a two-dimensional aiming movement. …
Fluorescence Studies Of Tomaymycin-Dna Adducts: Structure And Dynamics., Qi Chen
Fluorescence Studies Of Tomaymycin-Dna Adducts: Structure And Dynamics., Qi Chen
LSU Historical Dissertations and Theses
The relationship between ground-state structure and fluorescence lifetime of tomaymycin was studied using steady-state and time-resolved fluorescence, absorption, NMR, and photochemical techniques. Excited-state proton transfer and intersystem crossing were identified as the major nonradiative processes. Solvent isotope effect was found in aqueous solution, which did not involved C8OH. Photochemical H-D exchange on aromatic C6H and C9H were observed with similar rate. At 77 K, the total luminescence quantum yield was determined as 0.99. The quantum yield ratio of phosphorescence to fluorescence was 1.2. The limiting anisotropy was ${\sim}0.34$ for fluorescence and $-$0.1 for phosphorescence. The number and type of tomaymycin-DNA …
Self-Diffusion Of Semiflexible Rod-Like Poly-Gamma-Benzyl-Alpha, L-Glutamate In Dilute And Nondilute Isotropic Solutions., Zimei Bu
LSU Historical Dissertations and Theses
The self-diffusion coefficient (D$\sb{\rm s}$) of fluorescent dye labeled poly-$\gamma$-benzyl-L-glutamates (LPBLG) in pyridine solutions was measured by fluorescence photobleaching recovery (FPR). Intrinsic viscosity and static light scattering measurements showed that the LPBLGs did not aggregate in pyridine and that the rod structure of LPBLG was not perturbed by labeling. The measured concentrations spanned from dilute to the most concentrated isotropic solutions, and the axial ratios from 7 to 80 (M$\sb{\rm W}$ ranged from 20 000 to 232 000). The objective of this FPR study was to focus directly on the translational diffusion of a single LPBLG molecule in the absence …
Fundamental Studies Of Capillary Electroosmosis And Electrokinetic Removal Of Phenol From Kaolinite., Heyi Li
Fundamental Studies Of Capillary Electroosmosis And Electrokinetic Removal Of Phenol From Kaolinite., Heyi Li
LSU Historical Dissertations and Theses
Capillary electroosmosis is an important factor in capillary zone electrophoresis (CZE) and micellar electrokinetic capillary chromatography (MECC). A new application of electrokinetic phenomena in environmental science is electrokinetic soil processing, which is an emerging technique with the capability to decontaminate polluted soils. Chapter 1 discusses the fundamental theory behind electroosmosis, CZE, MECC, and electrokinetic soil processing. In chapter 2, the surface conductances of different concentrations of KCl solutions in 50 and 100 $\mu$m capillaries were measured using an AC method, to attempt to characterize capillary double layers. With increase of KCl concentration, the surface conductance increases. Chapter 3 involves fundamental …
Ultrafast Study Of Photochemistry On Chromium Hexacarbonyl Using Resonance Raman Spectroscopy., Soo-Chang Yu
Ultrafast Study Of Photochemistry On Chromium Hexacarbonyl Using Resonance Raman Spectroscopy., Soo-Chang Yu
LSU Historical Dissertations and Theses
In this dissertation ultrafast photochemistry of Cr(CO)$\sb6$ using picosecond resonance Raman spectroscopy is studied. The advantage of the transient resonance Raman spectroscopy for this study is demonstrated along with a Raman differencing technique. This study is divided into two main parts. The first part deals with the property of the electronic excited state of the Cr(CO)$\sb6.$ The attempt to reveal the excited electronic structure of Cr(CO)$\sb6$ is tried with the help of Albrecht vibronic theory and wave packet description. Reaction coordinate and Jahn-Teller effects have been investigated in detail. Two possible reaction coordinates are found in contrast to the results …
Investigating The Informational Nature Of A Modeled Visual Demonstration., Britta Gertrud Schoenfelder-Zohdi
Investigating The Informational Nature Of A Modeled Visual Demonstration., Britta Gertrud Schoenfelder-Zohdi
LSU Historical Dissertations and Theses
This study investigated the informational nature of a modeled visual demonstration of slalom-ski type movements performed on a ski simulator. Hypotheses exist suggesting that a model may convey information primarily about movement coordination (Newell, 1985), or movement form (Whiting, 1988), but there is no empirical evidence that this information is used by the learner so that skill acquisition is facilitated. To investigate this information question, three experiments were conducted that replicated and extended a study by Whiting, Bijlard, and den Brinker (1987) by analyzing movement kinematics of subjects in addition to movement outcome. In the first experiment, the expert model's …
The Spectroscopy Of Neutral And Ionic Forms Of Triphenylformazan Derivatives., Elizabeth Wilhite
The Spectroscopy Of Neutral And Ionic Forms Of Triphenylformazan Derivatives., Elizabeth Wilhite
LSU Historical Dissertations and Theses
The spectroscopic characteristics of neutral, protonated and deprotonated triphenylformazans were investigated by means of visible absorption and $\sp1$H NMR spectroscopies. Studies of the effect of solvents and substituents on the absorption spectra of the neutral and ionic formazans were conducted. CNDO/S calculations for a series of formazans were performed to assign the electronic transitions observed in the absorption spectra of triphenylformazan. The formazan system was found to be highly delocalized and not tautomeric as had been reported. The visible transition of the U (trans-syn) form of triphenylformazan was found to arise from orbitals localized on the formazan system. The near …
Ultrafast Measurement Of Chemical Dynamics In The Condensed Phase Using Transient Vibrational Spectroscopy., Xiaobing Xu
Ultrafast Measurement Of Chemical Dynamics In The Condensed Phase Using Transient Vibrational Spectroscopy., Xiaobing Xu
LSU Historical Dissertations and Theses
Geminate recombination and vibrational energy relaxation of iodine in the condensed phase are investigated using picosecond transient Raman spectroscopy. The advantages of transient Raman in measuring vibrational energy relaxation and separating different reaction dynamics are demonstrated in this dissertation. Using transient Raman spectroscopy we have for the first time directly observed geminate recombination and vibrational energy relaxation of I$\sb2$ on both X and $A\sp\prime$ $\sp3\Pi\sb{2u}$ states. For the X state, energy relaxation from vibrational levels ranging from $\upsilon$ = 52 to $\upsilon$ = 1 have been observed. These levels correspond to absolute energies of 9,300 to 210 cm$\sp{-1}$ above the …
Spectroscopy Of Hexamethyldipyrromethene Anion: Interactions With Metal Ions., Cristian Oscar Franco
Spectroscopy Of Hexamethyldipyrromethene Anion: Interactions With Metal Ions., Cristian Oscar Franco
LSU Historical Dissertations and Theses
This work includes: (1) a search for charge transfer interaction involving hexamethyldipyrromethene (HL) as a donor; (2) a spectroscopic study of hexamethyldipyrromethene anion (L$\sp-$), and, (3) an investigation of the spectroscopic characteristic of the copper chelate CuL$\sb2$. There are presented reactions in which HL may react with some electron acceptors. It is reported that TCNE interacts with HL to form a 1:1 complex that has an equilibrium constant of (2.5 0.9) $\times$ 10$\sp{15}$. Spectroscopic results indicate that haloacetones also interact with HL. Hexamethyldipyrromethene is a molecule that consists of two methyl substituted pyrrole rings joined by means of a vinyl …
Variability Of Practice And The Contextual Interference Effect In Motor Skill Acquisition., Kellie Green Hall
Variability Of Practice And The Contextual Interference Effect In Motor Skill Acquisition., Kellie Green Hall
LSU Historical Dissertations and Theses
The relationship between variability of practice and contextual interference was investigated in this study. The hypothesis proposed here was that these two effects are compatible, in that each addresses different learning situations. That is, the contextual interference effect relates only to situations where skill variations are controlled by different generalized motor programs, while practice variability relates only to situations where skill variations are parameter modifications of the same generalized motor program (Magill & Hall, in press). To test this compatibility hypothesis, two experiments were reported that were based on Wulf and Schmidt (1988). Blocked and random practice schedules were added …
I. Temporal Compression In Chirped Pulse Regenerative Amplification. Ii. Picosecond Time-Resolved Raman Study Of Excited State Charge Transfers., Yong Joon Chang
I. Temporal Compression In Chirped Pulse Regenerative Amplification. Ii. Picosecond Time-Resolved Raman Study Of Excited State Charge Transfers., Yong Joon Chang
LSU Historical Dissertations and Theses
The chirped pulse regenerative amplification in Nd:YAG lasers is demonstrated to be able to provide picosecond optical pulses with $\sim$gigawatt peak powers at a repetition rate of 2kHz. By taking advantage of the effects of gain narrowing and gain saturation in the regenerative amplifier, it is shown that the chirped amplified pulse width can be varied systematically from $\sim$12ps to 150ps. These high peak power pulses were utilized to perform several picosecond time-resolved resonance Raman spectroscopic experiments. One study involves the investigation of excited state electron transfer in symmetric and asymmetric polypyridineruthenium(II) complexes. The competing influences of solvent relaxation, vibrational …
Picosecond Resonance Raman Studies Of Solvent Effects On Electron Transfer In Ruthenium-Polypyridine Complexes., Takahiro Yabe
Picosecond Resonance Raman Studies Of Solvent Effects On Electron Transfer In Ruthenium-Polypyridine Complexes., Takahiro Yabe
LSU Historical Dissertations and Theses
Solvent effects in D$\sb3$ symmetric ruthenium-polypyridine complexes were studied by using excited state resonance Raman technique. Picosecond laser techniques were used to determine if electron transfer between ligands could be observed in an effort to learn about electron localization in ruthenium-polypyridine complexes. Ru(bpy)$\sb3\sp{2+}$ (bpy is 2,2$\sp\prime$-bipyridine), Ru(bpym)$\sb3\sp{2+}$ (bpym is 2,2$\sp\prime$-bipyrimidine), and Ru(Me$\sb2$-bpy)$\sb3\sp{2+}$ (Me$\sb2$-bpy is 4,4$\sp\prime$-dimethyl-2,2$\sp\prime$-bipyridine) were investigated in viscous glycerol solution at room temperature and -15$x$C. The viscosities of glycerol at these temperatures are 1487cP and 66500cP, respectively. It was found that in all three metal complexes investigated metal-to-ligand-charge-transfer state is already localized on the time scale of less than …