Chemistry Commons^™

Hydrogen Evolution Reaction Measurements Of Dealloyed Porous Nicu, Kyla Koboski, Evan Nelsen, Jennifer R. Hampton

Faculty Publications

Porous metals are of interest for their high surface area and potential for enhanced catalytic behavior. Electrodeposited NiCu thin films with a range of compositions were electrochemically dealloyed to selectively remove the Cu component. The film structure, composition, and reactivity of these samples were characterized both before and after the dealloying step using scanning electron microscopy, energy-dispersive spectroscopy, and electrochemical measurements. The catalytic behavior of the dealloyed porous Ni samples towards the hydrogen evolution reaction was measured and compared to that of the as-deposited samples. The dealloyed samples were generally more reactive than their as-deposited counterparts at low overpotentials, making …

Solar Energy Conversion And Control Using Organic Photovoltaic Cells, Kurt Wade Woods

Masters Theses & Specialist Projects

Organic photovoltaic (OPV) cells are advanced, newly emerging technologies that are lightweight, mechanically flexible devices with highthroughput processes from low cost material in a variety of colors. Rathnayake et al. of Western Kentucky University have developed a nanostructure-based OPV cell. Presented in this thesis is a model and simulation of a generalized PV powered system that can predict the performance of solar arrays in various environmental conditions. The simulation has been carried out in Matlab/Simulink, and upon entering the cell’s parameters, it provides key electrical characteristics such as the cell’s I-V curve and efficiency information. The total system that is …

Interactive Wireless Sensor For Remote Trace Detection And Recognition Of Hazardous Gases, Audrey Lama

Masters Theses & Specialist Projects

The interactive wireless sensor detects many hazardous gases such as Hexane, Propane, Carbon monoxide and Hydrogen. These gases are highly toxic and used in different kinds of manufacturing industries, domestic purpose and so on. So, building a sensor that can detect this kind of gases can save the environment; prevent the potential for explosion, and endangering human life. In long term, interactive wireless sensor can also prevent the financial losses that might occur due to the hazardous incident that might occur due to these toxic gases.

Hexane is a colorless, strong gas which inhaled in significant amounts by a person …

On The Origin Of Mode- And Bond-Selectivity In Vibrationally Mediated Reactions On Surfaces, Daniel Killelea, Arthur L. Utz

Chemistry: Faculty Publications and Other Works

The experimental observations of vibrational mode- and bond-selective chemistry at the gas–surface interface indicate that energy redistribution within the reaction complex is not statistical on the timescale of reaction. Such behavior is a key prerequisite for efforts to use selective vibrational excitation to control chemistry at the technologically important gas–surface interface. This paper outlines a framework for understanding the origin of non-statistical reactivity on surfaces. The model focuses on the kinetic competition between intramolecular vibrational energy redistribution (IVR) within the reaction complex, which in the long-time limit leads to statistical behavior, and quenching, scattering, or desorption processes that restrict the …

Vpt2+K Spectroscopic Constants And Matrix Elements Of The Transformed Vibrational Hamiltonian Of A Polyatomic Molecule With Resonances Using Van Vleck Perturbation Theory, Andreana M. Rosnik, William F. Polik

Faculty Publications

Vibrational levels of polyatomic molecules are analysed with Van Vleck perturbation theory to connect experimental energy levels to computed molecular potential energy surfaces. Vibrational matrix elements are calculated from a quartic potential function via second-order Van Vleck perturbation theory, a procedure that treats both weak and strong interactions among vibrational states by approximately block-diagonalising the vibrational Hamiltonian. A clear and complete derivation of anharmonic and resonance constants as well as general expressions for both on- and off-diagonal matrix elements of the transformed Hamiltonian is presented. The equations are written in partial fraction form and as a constant multiplied by a …

Structural And Magnetic Properties Of La₀.₇Sr₀.₃Mn₁₋ₓniₓo₃ (X ≤ 0.4), Thomas F. Creel, Jinbo Yang, Mehmet Kahveci, Satish K. Malik, Sylvio Quezado, Oran Allan Pringle, William B. Yelon, William Joseph James

Physics Faculty Research & Creative Works

We have studied the structural and magnetic properties of La_0.7Sr_0.3Mn_1-xNi_xO₃ (x = 0.05, 0.1, 0.20, 0.30, and 0.40) perovskites using x-ray and neutron diffraction and magnetic measurements. Our data consist of neutron (γ = 1.479Å) and x-ray (γ = 1.5481Å; Cu Kα) powder diffraction and magnetization measurements. We previously suggested these systems transition from ferromagnetic to antiferromagnetic ordering with the intermediate concentrations containing coexisting domains of ferromagnetically and antiferromagnetically ordered states. Upon further detailed examination, we find that the samples are homogeneous and that neutron data can be fitted to a …

Why Do Molecules Echo Atomic Periodicity?, Ray Hefferlin, Jonathan Sackett, Jeremy Tatum

Faculty Works

Franck–Condon factors are investigated for sequences of free

main-group diatomic molecules. Theory-based Condon loci

(parabolas) and Morse-potential loci are plotted on Deslandres

tables to verify if they, indeed, follow the largest Franck–Condon

factors. Then, the inclination angles of the Condon loci

are determined. Thus, entire band systems are quantified by

one variable, the angle. For all available isoelectronic sequences,

this angle increases from a central minimum toward

magic-number molecular boundaries. The theory for the Condon

locus gives the angle in terms of the ratio of the upperstate

to the lower-state force constants. It is concluded that

the periodicity is caused …

Volume 05, Ian Karamarkovich, Jessica Cox, Kyle Fowlkes, Allison Pawlowski, Kaitlin Major, Carrie Dunham, Kelsey Scheitlin, Kathryn Grayson, Ashley Johnson, Jennifer Nehrt, Kelsey Stolzenbach, Kristin Mcquarrie, Sara Nelson, Melisa Michelle, Jessica Sudlow, Perry Bason, Danielle Dmuchawski, Mariah Asbell, Matthew Sakach, Timothy Smith Jr., Annaliese Troxell, T. Dane Summerell, Sarah Ganrude, Malina Rutherford, Hannah Hopper, John Berry Jr., James Early, Colleen Festa, Chelsea D. Taylor, Michelle Maddox, Kaitlyn Smith, Sarah Schu, Cabell Edmunds, Katherine Grayson, Kayla Tornai

Incite: The Journal of Undergraduate Scholarship

Introduction from Dean Dr. Charles Ross

The Tallis House as an Extension of Emily Tallis in McEwan's Atonement by Ian Karamarkovich

Graphic Design by Jessica Cox

Graphic Design by Kyle Fowlkes

Graphic Design by Allison Pawlowski

Incorporating Original Research in The Classroom: A Case Study Analyzing the Influence of the Chesapeake Bay on Local Temperatures by Kaitlin Major, Carrie Dunham and Dr. Kelsey Scheitlin

Graphic Design by Kathryn Grayson

Graphic Design by Ashley Johnson

Facing the Music: Environmental Impact Assessment of Building A Concert Hall on North Campus by Jennifer Nehrt, Kelsey Stolzenbach And Dr. Kelsey Scheitlin

Art by Kristin …

Observation Of Ground-State Two-Neutron Decay, M Thoennessen, Z Kholey, A Spyrou, E Lunderberg, Paul A. Deyoung, H Attanayake, T Baumann, D Bazin, B A. Brown, G Christian, D Divaratne, S M. Grimes, A Haagsma, J E. Finck, N Frank, B Luther, S Mosby, T Nagi, Graham F. Peaslee, W A. Peters, A Schiller, J K. Smith, J Snyder, M Strongman, A Volya

Faculty Publications

Neutron decay spectroscopy has become a successful tool to explore nuclear properties of nuclei with the largest neutron-to-proton ratios. Resonances in nuclei located beyond the neutron dripline are accessible by kinematic reconstruction of the decay products. The development of two-neutron detection capabilities of the Modular Neutron Array (MoNA) at NSCL has opened up the possibility to search for unbound nuclei which decay by the emission of two neutrons. Specifically, this exotic decay mode was observed in¹⁶Be and ²⁶O.

Geometric-Phase Interference In A Mn12 Single-Molecule Magnet With Four-Fold Rotational Symmetry, S T. Adams, E H. Da Silva Neto, S Datta, J F. Ware, Christos Lampropoulos, G Christou, Y Myaesoedov, E Zeldov, Jonathan R. Friedman

Chemistry Faculty Research and Scholarship

We study the magnetic relaxation rate Gamma of the single-molecule magnet Mn₁₂-tBuAc as a function of magnetic field component H_T transverse to the molecule's easy axis. When the spin is near a magnetic quantum tunneling resonance, we find that Gamma increases abruptly at certain values of H_T. These increases are observed just beyond values of H_T at which a geometric-phase interference effect suppresses tunneling between two excited energy levels. The effect is washed out by rotating H_T away from the spin's hard axis, thereby suppressing the interference effect. Detailed numerical calculations of Gamma …

Surface Temperature Effects On The Dynamics Of N₂ Eley-Rideal Recombination On W(100), Ernesto Quintas-Sánchez, C. Crespos, P. Larrégaray, J. C. Rayez, L. Martin-Gondre, J. Rubayo-Soneira

Chemistry Faculty Research & Creative Works

Quasiclassical trajectories simulations are performed to study the influence of surface temperature on the dynamics of a N atom colliding a N-preadsorbed W(100) surface under normal incidence. A generalized Langevin surface oscillator scheme is used to allow energy transfer between the nitrogen atoms and the surface. The influence of the surface temperature on the N₂ formed molecules via Eley-Rideal recombination is analyzed at T = 300, 800, and 1500 K. Ro-vibrational distributions of the N₂ molecules are only slightly affected by the presence of the thermal bath whereas kinetic energy is rather strongly decreased when going from a …

Piezoelectric Microfiber Composite Actuators For Morphing Wings, Timothy Usher, Kenneth R. Ulibarri, Gilberto S. Camargo

Physics Faculty Publications

Morphing wing technologies provide expanded functionality in piloted and robotic aircraft, extending particular vehicle mission parameters as well as increasing the role of aviation in both military and civilian applications. However, realizing control surfaces that do not void the benefits of morphing wings presents challenges that can be addressed with microfiber composite actuators (MFCs). We present two approaches for realizing control surfaces. In one approach, flap-like structures are formed by bonding MFCs to each side of a metal substrate. In the other approach, MFCs are bonded directly to the wing. Counter intuitively, the flap approach resulted in larger voltage actuation …

Computer Code Verification And Cross Section Calculation For Promethium-147, Rita Inez Zell-Lusk

Nuclear Engineering Reports

The goals of this research are to (1) verify the predictions and accuracy of two computer codes which will be utilized in future research on Pm-147 production with data from a previous experiment and to (2) measure the cross section of Pm-147 for single neutron capture producing Pm-148 ground state and Pm-148 metastable state. The research in goal (1) used previous data obtained by James H. Hinderer in 2010 and a sample of Promethium-147 prepared by Rose Boll in 2006. The main elements of the new research done here included a correction of Mr. Hinderer’s data and the subsequent use …

Excitation Of Radiative Polaritons By Polarized Broadband Infrared Radiation In Thin Oxide Films Deposited By Atomic Layer Deposition, Anita J. Vincent-Johnson, Andrew E. Masters, Xiaofeng Hu, Giovanna Scarel

Department of Physics and Astronomy - Faculty Scholarship

This work contributes to the understanding of infrared radiation interaction with matter and its absorption for energy harvesting purposes. By exciting radiative polaritons in thin oxide filmswith polarized infrared radiation, a further evidence is collected that a link exists between radiative polaritons and the heat recovery mechanism hypothesized in previous research. In the voltage transient occurring when the infrared radiation is turned on, the observed time necessary to reach the maximum voltage and the voltage intensity versus angle of incidence exhibit a mismatch when generated by polarized and nonpolarized infrared radiation. The existence of collective charge oscillation modes in the …

The Roles Of Vertical Advection And Eddy Diffusion In The Equatorial Mesospheric Semi-Annual Oscillation (Msao), R. L. Gattinger, E. Kyrölä, C. D. Boone, W. F.J. Evans, K. A. Walker, I. C. Mcdade, P. F. Bernath, E. J. Llewellyn

Chemistry & Biochemistry Faculty Publications

Observations of the mesospheric semi-annual oscillation (MSAO) in the equatorial region have been reported dating back several decades. Seasonal variations in both species densities and airglow emissions are well documented. The extensive observations available offer an excellent case study for comparison with model simulations. A broad range of MSAO measurements is summarised with emphasis on the 80-100 km region. The objective here is not to address directly the complicated driving forces of the MSAO, but rather to employ a combination of observations and model simulations to estimate the limits of some of the underlying dynamical processes. Photochemical model simulations are …

Ace-Fts Version 3.0 Data Set: Validation And Data Processing Update, Claire Waymark, Kaley A. Walker, Chris D. Boone, Peter F. Bernath

Chemistry & Biochemistry Faculty Publications

No abstract provided.

Aqueous Red-Emitting Silicon Nanoparticles For Cellular Imaging: Consequences Of Protecting Against Surface Passivation By Hydroxide And Water For Stable Red Emission, Sheng-Kuei Chiu, Beth Ann Manhat, William J.I. Debenedetti, Anna L. Brown, Katye Fichter, Tania Vu, Micah Eastman, Jun Jiao, Andrea Mitchell Goforth

Chemistry Faculty Publications and Presentations

Stable, aqueous, red-to-near infrared emission is critical for the use of silicon nanoparticles (Si NPs) in biological fluorescence assays, but such Si NPs have been difficult to attain. We report a synthesis and surface modification strategy that protects Si NPs and preserves red photoluminescence (PL) in water for more than 6 mo. The Si NPs were synthesized via high temperature reaction, liberated from an oxide matrix, and functionalized via hydrosilylation to yield hydrophobic particles. The hydrophobic Si NPs were phase transferred to water using the surfactant cetyltrimethylammonium bromide (CTAB) with retention of red PL. CTAB apparently serves a double role …

Investigation Of Co, C2h6 And Aerosols In A Boreal Fire Plume Over Eastern Canada During Bortas 2011 Using Ground- And Satellite-Based Observations And Model Simulations, D. Griffin, K. A. Walker, J. E. Franklin, M. Parrington, C. Whaley, J. Hopper, J. R. Drummond, P. I. Palmer, K. Strong, T. J. Duck, P. F. Bernath

Chemistry & Biochemistry Faculty Publications

We present the results of total column measurements of CO, C₂H₆ and fine-mode aerosol optical depth (AOD) during the "Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites" (BORTAS-B) campaign over eastern Canada. Ground-based observations, using Fourier transform spectrometers (FTSs) and sun photometers, were carried out in July and August 2011. These measurements were taken in Halifax, Nova Scotia, which is an ideal location to monitor the outflow of boreal fires from North America, and also in Toronto, Ontario. Measurements of fine-mode AOD enhancements were …

Uncertainties In Modelling Heterogeneous Chemistry And Arctic Ozone Depletion In The Winter 2009/2010, I. Wohltmann, T. Wegner, R. Müller, R. Lehmann, M. Rex, G. L. Manney, M. L. Santee, P. Bernath, O. Suminska-Ebersoldt

Chemistry & Biochemistry Faculty Publications

Stratospheric chemistry and denitrification are simulated for the Arctic winter 2009/2010 with the Lagrangian Chemistry and Transport Model ATLAS. A number of sensitivity runs is used to explore the impact of uncertainties in chlorine activation and denitrification on the model results. In particular, the efficiency of chlorine activation on different types of liquid aerosol versus activation on nitric acid trihydrate clouds is examined. Additionally, the impact of changes in reaction rate coefficients, in the particle number density of polar stratospheric clouds, in supersaturation, temperature or the extent of denitrification is investigated. Results are compared to satellite measurements of MLS and …