Spectroscopic Studies of Gas-Phase Transition Metal Complexes of Cations and Cluster Ions with Methane and Water

The study of the non-covalent interactions between metals ions and ligands such as water and methane are key to understanding many processes including solvation, homogeneous catalysis and metals in biology. Similarly, the study of interactions between transition metal ions and cluster ions with hydrocarbons is of great importance in the understanding of C-H activation reactions which are involved in generation of fuels. Gas-phase metal complexes are good models for understanding the intrinsic interactions between the metal and the ligand. Understanding the mechanisms behind these interactions can be done by characterizing the structure and bonding in the molecular reactants, products, and intermediates. This characterization is made possible by combining experimental spectroscopy with computational studies to provide insight into molecular geometries and binding characteristics of ions. In this work, we explore two non-covalent interactions involved in solvation and catalysis by studying entrance-channel complexes of the reactions of transition metal ions with water and methane respectively. The motivations, techniques, apparatus, data acquisition and analysis methods are discussed in Chapters 1 and 2. Chapter 3 discusses the electronic spectroscopy of the 7B1 and 7B2 excited states of Mn+(H2O) and Mn+(D2O) measured using photodissociation spectroscopy. Progressions in the Mn+-H2O stretch are observed in both excited states, with the in-plane-bend also observed in the first excited state of Mn+(H2O), and the out-of-plane bend observed in the second excited state of both Mn+(H2O) and Mn+(D2O). Partially resolved rotational structure in the first excited state is analyzed. Chapter 4 discusses the vibrational spectroscopy of Fex+(CH4)n. Vibrational spectra are measured for Fe2+(CH4)n (n=1-3), Fe3+(CH4)n (n=1-3), and Fe4+(CH4)4 in the C-H stretching region (2650-3100 cm-1) using photofragment spectroscopy, monitoring loss of CH4. All spectra are dominated by an intense peak around 2800 cm-1, due to the symmetric C-H stretch. Density functional theory calculations are used to identify possible structures and geometries and to predict the spectra. Chapter 5 identifies possible extensions of the Chapter 3 and 4 studies to new first, second, and third-row transition metal-water and metal-methane complexes, as well as complexes of metal cluster ions with water and methane. Lastly, Chapter 5 describes alterations to the instrument

Making sense : a study of the dialogical nature of consciousness in creative writing.

The present study investigated the dynamics of a single participant's various I-positions ... using Stephenson's (1985) Q method, analysis of variance, factor analysis, and qualitative assessment of the participant's creative writing

Vibrational spectroscopy and theory of Fex+(CH4)N (x =2,3) (n = 1–3)

Vibrational spectra are measured for Fe$_x$$^+$(CH$_4$)$_n$ (x =2,3) (n = 1–3) in the C–H stretching region (2650–3100 cm$^{-1}$) using photofragment spectroscopy, by monitoring the loss of CH$_4$. All of the spectra exhibit an intense peak corresponding to the symmetric C–H stretch around 2800 cm$^{-1}$, which is red shifted by about 100 cm$^{-1}$ from free methane. The presence of a single peak suggests a nearly equivalent interaction between the methane ligands and the iron center. The peak becomes slightly less red shifted as the number of methane ligands increases. Density functional theory calculations, B3LYP and BPW91, are used to identify possible structures and predict the spectra. Results suggest that the methane(s) bind in a terminal configuration and that the Fe$_2$$^+$complexes are in the octet spin state while the Fe$_3$$^+$ complexes are in the dectet spin state. Lower C-H stretching frequencies are observed for Fe$_3$$^+$ complexes, indicating that the CH$_4$ interacts more strongly with Fe$_3$$^+$ than Fe$_2$$^+$

Frenzy: A Psychological Distance Account of Rumination, Mood, and Creativity

A reflective style of ruminative response to negative mood, as opposed to a brooding style, is linked to creativity (Verhaeghen, Joormann, & Aikman, 2014), especially when indecision is high (Cohen & Ferrari, 2010). In order to examine potential links between creativity and styles of ruminative response to positive mood (Feldman, Joormann, & Johnson, 2007), I adapted the Ruminative Responses Scale (RRS; Nolen-Hoeksema & Morrow, 1991)--a widely used measure of negative mood responses--to address positive mood responses (Positive Rumination Scale; PRS). Following tenets of psychological self-distance theory (Ayduk and Kross, 2008), I characterized Reflection and Brooding styles of negative mood response on the RRS as self-distant and self-immersed, respectively, and I characterized Interpreting and Basking (Martin & Tesser, 1996) styles of positive mood response on the PRS as self-distant and self-immersed, respectively. Whereas previous researchers found that a self-distanced response to negative mood predicts creativity, only a self-immersed response to positive mood predicted creativity when indecision was high in the present sample.Education (PhD

Modeling Axisymmetric Centrifugal Compressor Characteristics from First Principles

Turbochargers are a vital component for aiding engine manufacturers in meeting the latest emissions standards. However, their range of operation is limited for low mass flows by compressor surge. Operation in surge results in pressure and mass flow oscillations that are often damaging to the compressor and its installation. Since surge is a highly complex flow regime, full unsteady 3D models are generally too computationally expensive to run. The majority of current low-dimensional surge models use a cubic compressor characteristic that needs to be fitted to experimental data. Therefore, each time a compressor is studied using these models, costly experimental testing is required.In this paper, a new technique for obtaining an axisymmetric centrifugal compressor characteristic is presented. This characteristic is built using the equations of mass, momentum and energy from first principles in order to provide a more complete model than those currently obtained via experimental data. This approach enables us to explain the resulting cubic-like shape of the characteristic and hence to identify impeller inlet stall as a route into surge. The characteristic is used within a quasi-steady, map-based surge model in order to demonstrate its ability to predict the onset of surge while only providing geometric data as input. Validation is provided for this model by discussion of the qualitative flow dynamics and a good fit to experimental data, especially for low impeller speeds and pressure ratios

Changes in Sensorimotor Cortical Activation in Children Using Prostheses and Prosthetic Simulators

This study aimed to examine the neural responses of children using prostheses and prosthetic simulators to better elucidate the emulation abilities of the simulators. We utilized functional near-infrared spectroscopy (fNIRS) to evaluate the neural response in five children with a congenital upper limb reduction (ULR) using a body-powered prosthesis to complete a 60 s gross motor dexterity task. The ULR group was matched with five typically developing children (TD) using their non-preferred hand and a prosthetic simulator on the same hand. The ULR group had lower activation within the primary motor cortex (M1) and supplementary motor area (SMA) compared to the TD group, but nonsignificant differences in the primary somatosensory area (S1). Compared to using their non-preferred hand, the TD group exhibited significantly higher action in S1 when using the simulator, but nonsignificant differences in M1 and SMA. The non-significant differences in S1 activation between groups and the increased activation evoked by the simulator’s use may suggest rapid changes in feedback prioritization during tool use. We suggest that prosthetic simulators may elicit increased reliance on proprioceptive and tactile feedback during motor tasks. This knowledge may help to develop future prosthesis rehabilitative training or the improvement of tool-based skills

Developing and Testing of Low-cost 3D Printed Prostheses to Restore and Improve Function of Children with Congenital or Traumatic Amputations

The purpose of this investigation was to provide technical considerations and clinical evidence of the possible benefits and obstacles in the use of upper-limb 3D printed prostheses in paediatric populations. This information is crucial for clinicians interested in exploring the use of 3D printed prostheses for their patients. In the present study, children with congenital digit reductions (n=5); absent digits (one traumatic and four congenital) (n=5) and with upper-limb reductions (n=9). The perceived functionality of upper-limbs before the use of the prosthesis and after 4 months of use. In addition, gross dexterity, anthropometric measurements, active range of motion, and strength measurements were assessed before and after 6 month of using a low-cost 3D printed prosthetic hand. Their parents completed a survey at 1 and 3 months asking to quantify the time their child used the prosthesis on a daily basis in addition to the type of activities they performed with the prosthesis. The main finding of our studies is that the initial prosthesis design of the Cyborg Beast was not a functional solution for congenital paediatric patients with remnant opposition and pinch function, but significantly increased forearm circumference (Before=16.70±1.86 cm and After=17.80±1.48 cm), wrist active ROM flexion (Before=54.60±14.48° and After=68.40±14.29°), and active ROM extension (Before=40.40±37.75° and After=47.00±36.42° cm) after 6 months of use and can be incorporated in several activities at home and in school. However, 44% of our research participants reported durability issues and/or malfunctioning of these devices after 3 months of use

Intracranial Hypertension Secondary to Eosinophilic Meningitis Caused by Angiostrongylus Cantonensis

Angiostrongylus Cantonensis, a nematode, is a well-known cause of eosinophilic meningitis in endemic areas such as Southeast Asia, the Pacific Islands, and Hawaii. Nevertheless, an increasing number of cases in the southeast of the U.S. have been documented recently, specifically in Louisiana, Texas, and Florida. Infection is acquired after ingesting undercooked fresh water snails, mollusks, or undercooked vegetables contaminated by the slime from infected snails or slugs. Typical signs and symptoms include fever, general malaise, meningeal signs, headaches, photophobia, nausea and vomiting. Here we present a 23 year-old woman who presented to our emergency department with signs and symptoms consistent with intracranial hypertension, malaise, mild photophobia, and without fever, or meningeal signs. We also provide a review of the most recent literature regarding eosinophilic meningitis secondary to A. cantonensis