Digital Commons Network^™

Purine-Based Triazoles, Prakash Reddy, Nanditha G. Nair, Mark A. Smith, Wataru Kudo

Chemistry Faculty Research & Creative Works

A pharmaceutical composition for inhibiting at least protein kinase in a cell of a subject includes a purine based triazole.

Electrospray Of An Energetic Ionic Liquid Monopropellant For Multi-Mode Micropropulsion Applications, Steven P. Berg, Joshua L. Rovey, Benjamin D. Prince, Shawn W. Miller, Raymond J. Bemish

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The multi-mode chemical-electric propulsion capable energetic ionic liquid propellant [Emim][EtSO4]-HAN is electro sprayed in a 100 µm capillary emitter to test the electric-mode performance of the propellant. The ionic liquid exhibits stable electrospray emission in both cation and anion extraction modes at a nominal extraction voltage of 3400 V. Near field measurements of current and mass flow rate distribution are taken at flow rates from 0.19 nL/s to 3.06 nL/s. Total emission current, as measured by Faraday cup and integrated, increases from 754 nA to 3195 nA for cation emission and from 552 nA to 2012 nA for anion emission. …

Fano Resonances Realized In Thz Metamaterials Composed Of Continuous Metallic Wires And Split Ring Resonators, Z. Li, S. Cakmakyapan, B. Butun, C. Daskalaki, S. Tzortzakis, Xiaodong Yang, E. Ozbay

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

Light Localization Induced By A Random Imaginary Refractive Index, A. Basiri, Yaron Bromberg, Alexey Yamilov, Tsampikos Kottos

Physics Faculty Research & Creative Works

We show the emergence of light localization in arrays of coupled optical waveguides with randomness only in the imaginary part of their refractive index and develop a one-parameter scaling theory for the normalized participation number of Floquet-Bloch modes. This localization introduces a different length scale in the decay of the autocorrelation function of a paraxial beam propagation. Our results are relevant to a vast family of systems with randomness in the dissipative part of their impedance spatial profile.

The Missouri Miner, September 18, 2014

The Missouri Miner Newspaper

No abstract provided.

Coherent-State Path Integrals In The Continuum, G. Kordas, Simeon I. Mistakidis, A. I. Karanikas

Physics Faculty Research & Creative Works

We Discuss The Time Continuous Path Integration In The Coherent-State Basis In A Way That Is Free From Inconsistencies. Employing This Notion We Reproduce Known And Exact Results Working Directly In The Continuum. Such A Formalism Can Set The Basis To Develop Perturbative And Nonperturbative Approximations Already Known In The Quantum-Field-Theory Community. These Techniques Can Be Proven Useful In A Great Variety Of Problems Where Bosonic Hamiltonians Are Used.

The Missouri Miner, May 8, 2014

The Missouri Miner Newspaper

No abstract provided.

Investigating The Behaviour Of Natural Slopes And Man Made Structures By Terrestrial Sar Interferometry, Paolo Mazzanti

International Conference on Case Histories in Geotechnical Engineering

Remote sensing techniques for the monitoring of deformation are opening new opportunities in the field of geotechnical engineering and geology. Terrestrial SAR interferometry (TInSAR) is one of the most innovative technique and it promises to be a very effective solution which will be extensively used in the near future. TInSAR is characterized by several interesting features such as: i) high density of information; ii) fully remote capability; iii) long range capability; iv) widespread view; v) spatially continuous efficacy and vi) high accuracy. Thanks to these features TInSAR has been used for investigation and diagnostic purposes (i.e. landslide and structural instability …

Dynamical Reaction Pathways In Eley-Rideal Recombination Of Nitrogen From W(100), Ernesto Quintas-Sánchez, P. Larrégaray, C. Crespos, L. Martin-Gondre, J. Rubayo-Soneira, J. C. Rayez

Chemistry Faculty Research & Creative Works

The scattering of atomic nitrogen over a N-pre-adsorbed W(100) surface is theoretically described in the case of normal incidence off a single adsorbate. Dynamical reaction mechanisms, in particular Eley-Rideal (ER) abstraction, are scrutinized in the 0.1-3.0 eV collision energy range and the influence of temperature on reactivity is considered between 300 and 1500 K. Dynamics simulations suggest that, though non-activated reaction pathways exist, the abstraction process exhibits a significant collision energy threshold (0.5 eV). Such a feature, which has not been reported so far in the literature, is the consequence of a repulsive interaction between the impinging and the pre-adsorbed …

The Missouri Miner, March 15, 2012

The Missouri Miner Newspaper

No abstract provided.

Design And Development Of Ionic Liquid Dual-Mode Spacecraft Propellants, Steven P. Berg

Masters Theses

"Energetic ionic liquids capable of dual-mode chemical monopropellant or bipropellant and electric electrospray rocket propulsion are investigated. Following an extensive literature review, ionic liquids [Bmim][dca], [Bmim][NO₃], and [Emim][EtSO₄] are selected for study since their physical properties align well with the current state-of-the-art in chemical and electrospray propellants. Simulations show that these liquids will not be useful for monopropellant propulsion due to the prediction of solid carbon formation in the exhaust and performance 13-23% below that of hydrazine. Considering these ionic liquids as a fuel component in a binary monopropellant mixture with hydroxyl ammonium nitrate shows 1-4% improved specific impulse over …

A Planning Tool To Predict The Welding Angle In Laser Metal Deposition, Sriram Prabhu

Masters Theses

"Research in Laser Metal Deposition (LMD) has been done rigorously in the past. However, the main challenge that still exists is the production of complex part geometries having overhang features. Production of such features requires individual tracks with a high aspect ratio and wider bead angle. The use of destructible/ non-destructible support structures involves costly post production operations which increase production cost. Tilting or moving the deposition surface can be useful to create overhangs but are applicable only to special cases. Since such techniques have to be used by the manufacturing community, the techniques need to be simple in calculation …

Experimental Investigations Of Pseudospark Discharge And Pseudospark Produced Intense Electron Beams, Jing Hu

Doctoral Dissertations

"This dissertation focuses on the pseudospark discharge, a pulsed discharge discovered for the first time in 1970's. This dissertation is prepared as three journal articles in the style used by Missouri University of Science and Technology. A high voltage pseudospark discharge experiment setup, and discharge and electron beam diagnostic system are constructed and presented in this work. Three journal articles which have been published or are under review are presented in this dissertation on various topics of the pseudospark discharge.

Paper 1 "Experimental investigation of formation time in single-gap pseudospark discharge" is focused on experimental investigations of the time-dependent characteristics …

The Missouri Miner, September 1, 2011

The Missouri Miner Newspaper

No abstract provided.

The Missouri Miner, April 14, 2011

The Missouri Miner Newspaper

No abstract provided.

The Missouri Miner, January 20, 2011

The Missouri Miner Newspaper

No abstract provided.

Optimal Control Of A Helicopter Unmanned Aerial Vehicle (Uav), David John Nodland

Masters Theses

"This thesis addresses optimal control of a helicopter unmanned aerial vehicle (UAV). Helicopter UAVs may be widely used for both military and civilian operations. Because these helicopters are underactuated nonlinear mechanical systems, high-performance controller design for them presents a challenge. This thesis presents an optimal controller design via both state and output feedback for trajectory tracking of a helicopter UAV using a neural network (NN). The state and output-feedback control system utilizes the backstepping methodology, employing kinematic and dynamic controllers while the output feedback approach uses an observer in addition to these controllers. The online approximator-based dynamic controller learns the …

Simplified Theoretical Analysis Of The Seismic Response Of Artificially Compacted Gravels, Giuseppe Modoni, Anna Gazzellone

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Despite extensive use of gravely materials for the construction of big earthworks, theoretical prediction of their seismic response is often based on very simple schemes, unable to reproduce most of the important features observed at sample scales. Theoretical models capable of simulating the effects of artificial compaction on the stress-strain response of these soils under complex static and dynamic loading conditions would be particularly useful for designing more cost effective solutions in the construction of large embankments. This paper is aimed to fill this gap by reporting the results of a simplified theoretical study on the seismic response of an …

Characterization Of The Elastic Displacement Demand: Case Study - Sofia City, Ivanka Paskaleva, Mihaela Kouteva, Franco Vaccari, Giuliano F. Panza

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

The results of the study on the seismic site response of a part of the metropolitan Sofia are discussed. The neo-deterministic seismic hazard assessment procedure has been used to compute realistic synthetic waveforms considering four earthquake scenarios, with magnitudes M=3.7, M=6.3 and M = 7.0. Source and site specific ground motion time histories are computed along three selected cross sections, making use of the hybrid approach, combining the modal summation technique and the finite differences scheme. Displacement and acceleration response spectra are considered. These results are validated against the design elastic displacement response spectra and displacement demand, recommended in Eurocode …

Seismic P-Wave Polarization In The Context Of On-Site Early Warning System, Anton Zaicenco, Sharlie Huffman, Iain Weir-Jones

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Design of an on-site seismic early warning system for critical facilities, based on P-wave detection, requires knowledge of local seismicity, analysis of strong-motion records, and local geological settings. The scope of current paper is to present an efficient and reliable methodology for P-wave detection and discrimination. It is tolerant to the environmental, traffic and other types of noise at the location of the critical facility. The basic idea that is exploited in the proposed algorithm is the degree of P-wave polarization, which is obtained with Karhunen- Loève transform of the orthogonal triaxial records. A system consisting of borehole sensor array …

The Missouri Miner, February 18, 2010

The Missouri Miner Newspaper

No abstract provided.

Microbial-Induced Heterogeneity In The Acoustic Properties Of Porous Media, Caroline A. Davis, Laura J. Pyrak-Nolte, Estella A. Atekwana, D. Dale, Werkema, Marisa E. Haugen

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

It is not known how biofilms affect seismic wave propagation in porous media. Such knowledge is critical for assessing the utility of seismic techniques for imaging biofilm development and their effects in field settings. Acoustic wave data were acquired over a two-dimensional region of a microbial-stimulated sand column and an unstimulated sand column. The acoustic signals from the unstimulated column were relatively uniform over the 2D scan region. The data from the microbial-stimulated column exhibited a high degree of spatial heterogeneity in the acoustic wave amplitude, with some regions exhibiting significant increases in attenuation while others exhibited decreases. Environmental scanning …

Missouri S&T Magazine Summer 2009, Missouri S&T Marketing And Communications Department, Miner Alumni Association

Missouri S&T Magazine

No abstract provided.

Treatment Of Ion-Atom Collisions Using A Partial-Wave Expansion Of The Projectile Wavefunction, T. G. Wong, M. Foster, J. Colgan, Don H. Madison

Physics Faculty Research & Creative Works

We present calculations of ion-atom collisions using a partial-wave expansion of the projectile wavefunction. Most calculations of ion-atom collisions have typically used classical or plane-wave approximations for the projectile wavefunction, since partial-wave expansions are expected to require prohibitively large numbers of terms to converge scattering quantities. Here we show that such calculations are possible using modern high-performance computing. We demonstrate the utility of our method by examining elastic scattering of protons by hydrogen and helium atoms, problems familiar to undergraduate students of atomic scattering. Application to ionization of helium using partial-wave expansions of the projectile wavefunction, which has long been …

The Missouri Miner, April 9, 2009

The Missouri Miner Newspaper

No abstract provided.

The Missouri Miner, March 19, 2009

The Missouri Miner Newspaper

No abstract provided.

Investigating The Impact Of Microbial Interactions With Geologic Media On Geophysical Properties, Caroline A. Davis

Doctoral Dissertations

"The goals of this study were to investigate the effect of: (1) microbial metabolic byproducts, microbial growth, and biofilm formation on the low frequency electrical properties of porous media, (2) biofilm formation on acoustic wave properties, and (3) the natural electrical (self-potential) signatures associated with an in-situ biological permeable reactive barrier (PRB). The results suggest: (1) increases in electrolytic conductivity are consistent with increased concentrations of organic acids and biosurfactants; (2) mineral weathering promoted by organic acids causes increases in electrolytic conductivity, concomitant with increases in major cation concentrations; (3) interfacial conductivity generally parallels microbial cell concentrations and biofilm formation; …

Antibacterial Coatings For Medical Devices Based On Glass Polyalkenoate Cement Chemistry, A. Coughlan, D. Boyd, C. W.I. Douglas, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

A biofilm is an accumulation of micro-organisms and their extracellular products forming a structured community on a surface. Biofilm formation on medical devices has severe health consequences as bacteria growing in this lifestyle are tolerant to both host defense mechanisms and antibiotic therapies. However, silver and zinc ions inhibit the attachment and proliferation of immature biofilms. The objective of this study is to evaluate whether it is possible to produce silver and zinc-containing glass polyalkenoate cement (GPC) coatings for medical devices that have antibacterial activity and which may therefore inhibit biofilm formation on a material surface. Two silver and zinc-containing …

Missouri S&T Magazine Winter 2008, Missouri S&T Marketing And Communications Department, Miner Alumni Association

Missouri S&T Magazine

No abstract provided.

Extraction Of The Species-Dependent Dipole Amplitude And Phase From High-Order Harmonic Spectra In Rare-Gas Atoms, Anh-Thu Le, Toru Morishita, C. D. Lin

Physics Faculty Research & Creative Works

Based on high-order harmonic generation (HHG) spectra obtained from solving the time-dependent Schrödinger equation for atoms, we established quantitatively that the HHG yield can be expressed as the product of a returning electron wave packet and photorecombination cross sections, and the shape of the returning wave packet is shown to be largely independent of the species. By comparing the HHG spectra generated from different targets under identical laser pulses, accurate structural information, including the phase of the recombination amplitude, can be retrieved. This result opens up the possibility of studying the target structure of complex systems, including their time evolution, …