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Hydroxyl- Terminated Dendrimers With Sulfonimide Linkers As Binders For Metals Of Industrial Significance, Khaleel Abu Sbeih, Mohammad Al Harahsheh

Turkish Journal of Chemistry

First- and second-generation hydroxyl- terminated dendrimers were prepared starting from a 1,3-diaminopropane core and sulfonimide linkers. A first-generation mesitylene-derived dendrimer was also prepared with the same terminals. The dendrimers were then reacted with Fe3+, Al3+, and UO22+ separately in order to apply the dendrimers for binding these metals, which have important industrial applications and pose environmental problems simultaneously. The prepared dendrimers were also shown to bind Fe3+ selectively from mixtures with Al3+.

Recovering Lost Exposure From The Majorana Demonstrator And Testing Data Selection Assumptions, Thomas Lannen

Theses and Dissertations

The Majorana Demonstrator recently concluded its search for neutrinoless double beta decay using an array of up to 40.4kg of germanium detectors, 27kg of which were enriched in ⁷⁶Ge and housed inside a copper and lead compact shield located at the 4850 foot level in a clean room in the Davis Campus of the Sanford Underground Research Facility (SURF) in Lead, South Dakota. This search proceeded from June 26, 2015 until March 3, 2021 and 64.5 kg yr of enriched active exposure was acquired while achieving a world leading energy resolution of 0.12% FWHM at 2039 keV, one of …

Acidification Of Northeastern Usa Lakes From Rising Anthropogenic-Sourced Atmospheric Carbon Dioxide And Its Effects On Aluminum Speciation, Karen H. Johannesson, Jaxon Dii Horne, Anant Misra, Catherine Aliperta, Orpheus V. Meletis, Robert C. Santore, Christopher D. White, Georgia Mavrommati, David J. Burdige

OES Faculty Publications

The impact of rising atmospheric CO₂ (pCO₂^atm) from anthropogenic activities on pH, dissolved inorganic carbon, carbonate mineral saturation, and aluminum (Al) speciation is evaluated for 18 northeastern USA lakes using polythermal, sliding activity reaction path models. pCO₂^atm was forced using two scenarios from the IPCC's Sixth Assessment Report in which pCO₂^atm attains either 600 or 1,100 ppm in 2,100. Results suggest pH will decrease 0.15 and 0.32 pH units, _aCO^2-₃ will decrease 24% and 49%, and Ω_aragonite will decrease 21% and 45%, respectively. These changes are of the same …

Intergranular And Pitting Corrosion Mechanisms Of Sensitized Aluminum Alloy Aa5083, Clayton Egleston

Williams Honors College, Honors Research Projects

The motivation and objectives of this project is to examine the mechanisms of intergranular corrosion (IGC) and pitting corrosion of sensitized AA5083. In this regard, different characterization techniques were used, including optical analysis of microstructure, cyclic potentiodynamic polarization with Tafel fitting, electrochemical impedance spectroscopy with electrical equivalent circuit (EEC) fitting, and potentiostatic current transient monitoring. The transition from IGC to pitting corrosion occurs when the grain boundaries become saturated with the β-phase (Mg₂Al₃). It was found that AA5083 becomes more vulnerable to pitting corrosion as the degree of sensitization increases.

Seasonal Dynamics Of Dissolved Iron On The Antarctic Continental Shelf: Late-Fall Observations From The Terra Nova Bay And Ross Ice Shelf Polynyas, P. N. Sedwick, B. M. Sohst, C. O'Hara, S. E. Stammerjohn, B. Loose, M. S. Dinniman, N. J. Buck, J. A. Resing, S. F. Ackley

OES Faculty Publications

Over the Ross Sea shelf, annual primary production is limited by dissolved iron (DFe) supply. Here, a major source of DFe to surface waters is thought to be vertical resupply from the benthos, which is assumed most prevalent during winter months when katabatic winds drive sea ice formation and convective overturn in coastal polynyas, although the impact of these processes on water-column DFe distributions has not been previously documented. We collected hydrographic data and water-column samples for trace metals analysis in the Terra Nova Bay and Ross Ice Shelf polynyas during April-May 2017 (late austral fall). In the Terra Nova …

Ab-Initio And Empirical Simulations Of Aluminum And Copper Metal, William Wolfs

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this work, I perform detailed calculations on the bulk and electronic properties of aluminum and copper metal. Originally, I was motivated by experimental work on the solidsolid phase changes in pure aluminum. These phase changes were well predicted by density functional theory(DFT) but difficult or impossible to predict using embedded atom method potentials(EAM). EAM potentials are in wide use to describe many properties of bulk materials, and it seemed worrying that something so basic as a phase change could not be predicted. I began running high precision calculations with DFT and compared the results to EAM potentials which had …

Adapting Tropical Forages To Low-Fertility Soils, Idupulapati M. Rao

IGC Proceedings (1997-2023)

Tropical forages growing in low-fertility acid soils usually increase the amount of dry matter partitioned to roots at the expense of shoot growth, but substantially different adaptive attributes to such soils have been found, both between and within species. By possessing the C₄ pathway of photosynthesis, grasses are more efficient than legumes in using N, Ca, and P, whereas legume roots are more efficient in extracting nutrients from low-fertility soils. Phosphorus uptake efficiency (mg of P uptake in shoot biomass per unit root length) of the legume Arachis pintoi is several times higher than that of the grass Brachiaria …

Data-Driven Algorithm To Classify The Degree Of Isotropy In The Bidirectional Reflectance Distribution Function, Anne W. Werkley, Samuel D. Butler, Todd V. Small, Michael A. Marciniak

Faculty Publications

The bidirectional reflectance distribution function (BRDF) is used to describe reflectances of materials by calculating the ratio of the reflected radiance to the incident irradiance. While it was found that the isotropic models maintained symmetry about ϕ_s  =  π, such symmetry was not maintained about the θ_s  =  θ_i axis, except for close to the specular peak. This led to the development of a data-driven metric for how isotropic a BRDF measurement is. Research efforts centered around developing an algorithm that could determine material anisotropy without having to fit to models. This algorithm was tested using high …

Investigating Gallium Inclusion In Aluminum And Iron Oxyhydroxides, Corey A. Palmer

Masters Theses

Because Ga shares many physicochemical properties with Al and Fe, Ga may be able to incorporate into Al and Fe oxy-hydroxides. Understanding how Ga incorporates into these oxy-hydroxides may be crucial for finding Ga-rich bauxite deposits. In order to find the difference in Ga inclusion rates into oxy-hydroxides, as well as understand the mechanisms for this Ga inclusion, Al and Fe oxy-hydroxides were synthesized in the lab with Ga additions of 2 mol % Ga and 20 mol % Ga for a low-Ga and high-Ga treatment, respectively, along with a no added Ga control. X-Ray diffraction analyses confirmed the formation …

Comparison Of Aluminum And Manganum Concentration In Akmola Region, Kazakhstan, A. G. Zhumalina, E. K. Sambayev, A. Sakaguchi, S. Endo, K. Tanaka, T. Kajimoto, N. Kawano, T. B. Suleimenov, K. Sh. Zhumadilov, M. Hoshi

Eurasian Journal of Physics and Functional Materials

The results of seasonal Al and Mn activity on the surface of the atmosphere above the city of Nur-Sultan are shown from October 2016 to January 2017. The technique of sampling aerosols in various fractions and further analysis of the data are described. Together with scientists from the University of Hiroshima (Hiroshima, Japan) and the University of Tsukuba (Tsukuba, Japan), the composition of aerosols in the air of Astana was monitored. The aim of the project was to develop a methodology for sampling aerosols in various fractions and conduct measurements on an ongoing basis. The studies were carried out using …

Strategies For Determining Electron Yield Material Parameters For Spacecraft Charge Modeling, Phil Lundgreen, John R. Dennison

All Physics Faculty Publications

Accurate modeling of spacecraft charging is essential to mitigate well‐known and all‐too‐common deleterious and costly effects on spacecraft resulting from charging induced by interactions with the space plasma environment. This paper addresses how limited availability of electron emission and transport properties of spacecraft materials—in particular, secondary electron yields—and the wide ranges measured for such properties pose a critical issue for modeling spacecraft charging. It describes a materials charging database for electron emission properties under development, which facilitates more accurate spacecraft charge modeling when used in concert with the strategies outlined herein. These data and techniques provide tools for more accurate …

Preparation, Characterization, And Binding Profile Of Imprinted Semi-Ipn Cryogel Composite For Aluminum, Shahnila Shah, Huma Shaikh, Najma Memon, Muhammad Igbal Bhanger, Tahira Qureshi, Humaira Khan, Adi̇l Deni̇zli̇

Turkish Journal of Chemistry

Human body is greatly exposed to aluminum due to its high abundance in the environment. This nonessential metal is a threat to the patients of chronic renal disorders, as it is easily retained in their plasma and quickly accumulates in different tissues. Thus, there is great need to remove it from the aqueous environment. In this study, Al$^{3+}$ imprinted semiinterpenetrating polymer network (semi-IPN)-based cryogel composite was prepared and applied for the purification of environmental and drinking water samples from aluminum. Poly (2-hydroxyethyl methacrylate) (pHEMA) discs were produced via cryogenic treatment and imprinted semi-IPN was introduced to the 3-(trimethoxysilyl) propyl acrylate-modified …

Reactive Wetting Of Metallic/Ceramic (Al/Α-Al2 O3 ) Systems: A Parallel Moleculardynamics Simulation Study, Gürcan Aral

Turkish Journal of Physics

The reactive wetting process of a flat solid alumina (α-Al2 O3) ceramic surface by metallic aluminum (Al) nanodroplets with different shapes (spherical, cylindrical, and layer) is studied using parallel molecular dynamics (MD) simulations based on a variable charge MD method, with focuses on heat transfer, mass transfer, and the structure of the reactive region at the Al/α-Al2 O3 interface. We find that the diffusion of oxygen (O) atoms from the substrate into the droplet leads to the formation of a continuous layer of reaction product at the interface. The diffusion length of oxygen atoms into the spherical Al droplet is …

Magnetic Solid-Phase Extraction Based On Coriolus Versicolor-Immobilized $\Gamma $-Fe$_{2}$O$_{3}$ Nanoparticles For Preconcentration And Determination Of Al(Iii) In Water And Food Samples, Sadi̇n Özdemi̇r, Mustafa Serkan Yalçin, Ersi̇n Kilinç, Mustafa Soylak

Turkish Journal of Chemistry

A method for preconcentration of Al(III) prior to its determination by inductively coupled plasma-optical emission spectrometry (ICP-OES) was developed because the sensitivity of ICP-OES is insufficient for trace-level measurement of Al(III). The method is based on the use of Coriolus versicolor}-immobilized $\gamma $-Fe$_{2}$O$_{3}$ magnetic nanoparticles as a solid phase sorbent. The best experimental conditions were found as pH 6.0, 2.0 mL/min flow rate, 100 mg amount of C. versicoloron 150 mg of $\gamma $-Fe$_{2}$O$_{3}$ nanoparticles, and 500 mL of sample volume. The Al(III) absorbed on biosorbent was eluted with 5.0 mL of 1.0 mol/L HCl. Limit of detection, limit of …

The Structure And Stability Of Cationic Metal-Benzene Clusters, Daniel P. Rabayda

Theses and Dissertations

We have investigated the size-dependent stability and structure of benzene, aluminum-benzene, and vanadium-benzene clusters. Motivated by gas-phase experimental studies performed by an experimental collaborator, we have used first-principle electronic structure methods to identify the structure of Al⁺(Bz)_n, V⁺(Bz)_n, and Bz_n clusters. Our studies reveal that cationic aluminum-benzene clusters have a magic number of 13, and that its high stability may be understood by analyzing the structure of the cluster. We also investigate the structure of vanadium-benzene clusters which have a magic number of 2. Here I examine the benzene-cation and benzene-benzene …

Nonlinear Optical Characterization Of Solids, Alex Farnsworth

Undergraduate Honors Theses

Vibrational Sum Frequency Generation (VSFG) and the similar Second Harmonic Generation (SHG) are both classified as nonlinear optical phenomena, with the hallmark trait being that the input and output frequencies are different. Both of these systems are remarkable tools due to their surface specific nature. Still, there is much that is not known about the response from these systems, especially the nonresonant SFG response. We have worked to better understand SFG signal, specifically the nonresonant temporal profile. We have also collected results that call into question some underlying assumptions about time-based suppression methods when working with single crystal substrates.

As …

The Effects Of Seasonal Variations In Chemistry And Hydrology On The Microbial Community And Its Sulfide Oxidation Potential In A Naturally Acidic Maine Stream, Raymond C. Kahler Iii

Electronic Theses and Dissertations

Sulfide minerals oxidize through interaction with water and oxygen, releasing hydrogen ions. The process often occurs naturally near metal sulfide deposits, and can be accelerated through mining. Microorganisms accelerate the rate of sulfide oxidation. Acidified streams typically contain high metal concentrations (e.g. aluminum) and microbes in these systems may develop resistances to metal toxicity. Stream flow can affect sulfide oxidation and microbial community structure. Baseflow can influence stream chemistry from interactions with the surrounding bedrock, while stormflow affects stream chemistry and the local microbial community through dilution and addition of microbes transported by runoff. Microbial community composition is affected by …

Superhydrophobic Surface On Aluminum Alloy By Hydrothermal Method And Its Electrochemical Performance, Xiao-Hang Chen, Mo-Jing Chen, Yu-Lin Min, Qun-Jie Xu

Journal of Electrochemistry

Superhydrophobic film formed on a metal surface is an effective way for corrosion protection. In this paper, the superhydrophobic film was prepared on the surfaces of aluminum alloy by hydrothermally treating with a solution containing CeCl₃·7H₂O and CO(NH₂)₂ , and a self-assemble process. The electrochemical measurements and surface morphology results confirmed that the best superhydrophobicity and electrochemical performance could be achieved with the contact angle of 155.5^o after six hours of hydrothermal reaction. Furthermore, the inhibition efficiency of 99.6% was obtained in 3.5 wt% NaCl aqueous solution, indicating the excellent corrosion resistance …

Lithography-Free, Omnidirectional, Cmos-Compatible Alcu Alloys For Thin-Film Superabsorbers, Mariama Rebello De Sousa Dias, Chen Gong, Zachary A. Benson, Marina S. Leite

Physics Faculty Publications

Superabsorbers based on metasurfaces have recently enabled the control of light at the nanoscale in unprecedented ways. Nevertheless, the sub‐wavelength features needed to modify the absorption band usually require complex fabrication methods, such as electron‐beam lithography. To overcome the scalability limitations associated with the fabrication of metallic nanostructures, engineering the optical response of superabsorbers by metal alloying is proposed, instead of tuning the geometry/size of the nanoscale building blocks. The superior performance of thin film AlCu alloys as the metallic component of planar bilayer superabsorbers is numerically demonstrated. This alloy outperforms its pure constituents as well as other metals, such …

Developing Instrumentation For Fabricating And Characterizing Thin Film Aluminum Mirrors, P. Claire Segura

Student Works

The best material for constructing a mirror for a broad-bandwidth telescope that is also capable of reflecting EUV light is pure aluminum. In order to test how the reflectance of aluminum in the EUV range changes as it oxidizes, a system has been constructed that allows a thin aluminum mirror to be constructed inside of a vacuum, where its reflectance can then be tested immediately. Because the experiment must take place in a vacuum, it must also be controlled remotely through a computer program, which manages the mirror fabrication process as well as the collection and analysis of reflectance data. …

Highly Selective Schiff Base Derivatives For Colorimetric Detection Of Al$^{3+}$, Zi̇ya Aydin, Mustafa Keleş

Turkish Journal of Chemistry

Schiff base derivatives NBAR and NSAR were developed for selective detection of Al$^{3+}$ in aqueous solution. UV-vis spectroscopic studies revealed that NBAR and NSAR showed marked sensitivity and selectivity to Al$^{3+}$ in acetonitrile (ACN)/water (v/v, 1:1, pH 6.80). The NBAR and NSAR receptors bound Al$^{3+}$ in a 2:1 stoichiometry with apparent binding constants 4.09 $\times $ 10$^{11}$ M$^{-2}$ and 1.65 $\times $ 10$^{12}$ M$^{-2}$, respectively. They also displayed distinct changes in color upon the alteration of free Al$^{3+}$ levels in solution with reversible responses and showed little interference with other metal ions.

Corrosion Of Aluminum Current Collector In Cost Effective Rechargeable Lithium-Ion Batteries, Shengyi Li

Theses and Dissertations

Rechargeable lithium ion batteries (LIB) have been widely used as commercial energy storage systems for portable equipment, electronic devices and high power applications (e.g. electronic vehicles). One issue with the commercialized LIB is that expensive, highly toxic and flammable organic solvents are used in the electrolyte and the fabrication process of electrodes. The toxic organic based solvents increase the production cost and lead to significant safety concerns in the event of a battery overcharge or short circuit. The recent development of “green manufacturing” technology allows manufacturers to replace the organic solvents used in the cathode coating process by aqueous based …

Improved Analysis Of Gw150914 Using A Fully Spin-Precessing Waveform Model, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

This paper presents updated estimates of source parameters for GW150914, a binary black-hole coalescence event detected by the Laser Interferometer Gravitational-wave Observatory (LIGO) in 2015 [Abbott et al. Phys. Rev. Lett. 116, 061102 (2016).]. Abbott et al. [Phys. Rev. Lett. 116, 241102 (2016).] presented parameter estimation of the source using a 13-dimensional, phenomenological precessing-spin model (precessing IMRPhenom) and an 11-dimensional nonprecessing effective-one body (EOB) model calibrated to numerical-relativity simulations, which forces spin alignment (nonprecessing EOBNR). Here, we present new results that include a 15-dimensional precessing-spin waveform model (precessing EOBNR) developed within the EOB formalism. We find good agreement …

Preventing Oxidation Of Aluminum Films With Cadmium Of Zinc Barriers, Spencer B. Perry

Student Works

The planned Large UV/Optical/Near-infrared Telescope (LUVOIR) is expected to launch sometime in the 2030s if NASA surveys recommend LUVOIR over several other projects in early developmental stages [1]. As the project title suggests, the proposed telescope would include large mirrors (between 8 and 16 meters) as part of the orbiting reflector telescope. My research focused on the preparation of aluminum mirrors with zinc or cadmium barrier layers that were designed to prevent oxidation of the aluminum.

Spectroscopic Imaging Of Aluminum Containing Plasma, David Michael Surmick

Doctoral Dissertations

This dissertation aims to characterize laser-induced plasma from a physics point of view as warm, dense matter. Use of nominal nanosecond pulsed laser radiation initiates a plasma with electron temperatures of the order of 10 electron volts and electron densities of the order of air species densities at standard ambient temperature and pressure. For laser ablation and/or optical breakdown at or near a solid surface, the electron density can amount to be 1000 times greater. Spectroscopic investigations of the plasma emissions provide a method by which the electron density, temperature, and shockwave expansion may be determined. Of particular interest are …

Hyperfine Rather Than Spin Splittings Dominate The Fine Structure Of The B 4Σ-–X 4Σ- Bands Of Aic, Dennis J. Clouthier, Aimable Kalume

Chemistry Faculty Publications

Laser-induced fluorescence and wavelength resolved emission spectra of the B ⁴Σ⁻–X ⁴Σ⁻ band system of the gas phase cold aluminum carbide free radical have been obtained using the pulsed discharge jet technique. The radical was produced by electron bombardment of a precursor mixture of trimethylaluminum in high pressure argon. High resolution spectra show that each rotational line of the 0-0 and 1-1 bands of AlC is split into at least three components, with very similar splittings and intensities in both the P- and R-branches. The observed structure was reproduced by assuming b …

Galvanically Induced/Accelerated Crevice Corrosion, Zachary R. Roland

Williams Honors College, Honors Research Projects

In this thesis, a one dimensional model is developed to investigate the initial stages of corrosion in a fastener assembly consisting of a stainless steel fastener and aluminum 7075 as the plate. Differential equations are formulated and solved to determine the profiles for the potential, the oxygen concentration, and the aluminum ion concentration in the crevice, and also the potential in the bulk electrolyte. This fastener system exhibits galvanic corrosion, pitting corrosion, and crevice corrosion. It is found that the potential decreases monotonically down the length of the crevice, the oxygen concentration decreases exponentially down the length of the crevice, …

Development And Demonstration Of Critical Components Of Aluminum Based Energy Storage Devices Using The Chloroaluminate Ionic Liquids, Mengqi Zhang

Doctoral Dissertations

This dissertation considers the development of porous carbon materials as the substrates for Al deposition/dissolution in an Al based ionic liquid flow battery (ILFB) and demonstration of an Al based hybrid supercapacitor. The Aluminum chloride/ 1-ethyl-3-methylimidazolium chloride chloroaluminate ionic liquid is utilized as the electrolyte for these Al based energy storage devices. The ILFB has less capital cost than the all-vanadium redox flow battery because of the inexpensive AlCl₃. The feasibility to equip a tank of solid aluminum chloride in an ILFB system aiming to improve energy density is investigated. A critical range of temperature data (50-130 celsius …

Combinatorial Investigation Of Magnetostriction In Fe-Fa And Fe-Ga-Al, Jason R. Hattrick-Simpers, Dwight Hunter, Corneliu M. Craciunescu, Kyu Sung Jang, Makoto Murakami, James Cullen, Manfred Wuttig, Ichiro Takeuchi, Samuel E. Lofland, Leonid Bendersky, Noble Woo, Robert Bruce Vandover, Toshiya Takahashi, Yasubumi Furuya

Jason R. Hattrick-Simpers

A high-throughput high-sensitivity optical technique for measuringmagnetostriction of thin-film composition-spread samples has been developed. It determines the magnetostriction by measuring the induced deflection of micromachined cantilever unimorph samples. Magnetostrictionmeasurements have been performed on as-deposited Fe–Ga and Fe–Ga–Al thin-film composition spreads. The thin-film Fe–Ga spreads display a similar compositional variation of magnetostriction as bulk. A previously undiscovered peak in magnetostriction at low Ga content was also observed and attributed to a maximum in the magnetocrystalline anisotropy. Magnetostrictive mapping of the Fe–Ga–Al ternary system reveals the possibility of substituting up to 8at.%Al in Fe₇₀Ga₃₀ without significant degradation of magnetostriction.

Producing High Strength Aluminum Alloy By Combination Of Equal Channel Angular Pressing And Bake Hardening, Hamid Alihosseini, Mohsen Asle Zaeem, Kamran Dehghani, Ghader Faraji

Materials Science and Engineering Faculty Research & Creative Works

A combination of severe plastic deformation by equal channel angular pressing (ECAP) and bake hardening (BH) was used to produce high strength ultrafine-grained AA6061 aluminum alloy. 2, 4 and 8 passes of ECAP were performed, and the bake hardenability of samples was tested by 6% pre-straining followed by baking at 200 °C for 20 min. The microstructures obtained for various passes of ECAP were characterized by XRD, EBSD, and TEM techniques. The microstructures were refined from an average grain size of 20 µm to 212 nm after 8 passes of ECAP. Maximum bake hardenability of 110 MPa, and final yield …