Physical Sciences and Mathematics Commons^™

Applying Bioactive Glass Beads For Long-Term Drug Delivery, Marie O. Sykes, Rashi Sharma

Physics and Astronomy Presentations

Bioactive glass beads have been used to distribute medicine over extended periods of time in limited uses. They can be engineered to have a porous and hollow structure, and using Mo-Sci's OL-GL 1756b (1756b), the fundamental notion of dosage distribution can be tested in preparation to design the optimal glass for medicine distribution. A few key factors in this is how long does it take the liquid to release from the beads, how do the beads decay, and how well the glass can bond to human tissue. This research demonstrates the capacities of the 1756b type as a promising start …

Periodicities And Plasma Density Structure Of Jupiter’S Dawnside Magnetosphere, Xuanye Ma, A.A. Schok, P.A. Delamere, B. Mino, P.A. Damiano, B. Zhang, A. Sciola

Publications

The ability to quantify variations in magnetic field topology and density within Jupiter’s magnetosphere is an important step in understanding the overall structure and dynamics. The Juno spacecraft has provided a rich data set in the dawnside magnetosphere. The recent Grid Agnostic MHD for Extended Research Applications (GAMERA) global simulation study by Zhang et al. (2021) showed a highly structured plasmadisc with closed magnetic field lines mapping between the outer dawn-tail flank and the high latitude polar region. To test these model predictions, we examined Juno’s magnetic field data and electron/energetic particle data to categorize portions of orbits 1-15 into …

Low-Volume Magmatism Linked To Flank Deformation On Isla Santa Cruz, Galápagos Archipelago, Using Cosmogenic 3He Exposure And 40Ar/39Ar Dating Of Fault Scarps And Lavas, D. M. Schwartz, K. Harpp, M. D. Kurz, E. Wilson, R. Van Kirk

Geosciences Faculty Publications and Presentations

Isla Santa Cruz is a volcanic island located in the central Galápagos Archipelago. The island’s northern and southern flanks are deformed by E–W-trending normal faults not observed on the younger Galápagos shields, and Santa Cruz lacks the large summit calderas that characterize those structures. To construct a chronology of volcanism and deformation on Santa Cruz, we employ ⁴⁰Ar/³⁹Ar geochronology of lavas and ³He exposure dating of fault scarps from across the island. The combination of Ar–Ar dating with in situ-produced cosmogenic exposure age data provides a powerful tool to evaluate fault chronologies. The ^{40 …}

A Computational Study Of Genotype-Phenotype Mutation Patterns, Kamaludin Dingle, Omar Tawfik, Ahmed Aldabagh

Undergraduate Research Symposium

Understanding properties of genotype-phenotype maps is important for understanding biology and evolution. In this project we make a computational study of the statistical effects of genetic mutations, in particular computing the probabilities of each phenotype transitioning to any other phenotype. We also investigate the importance of the local phenotypic environment of a single genotype, and its role in determining mutation transition probabilities. We use HP protein folding, RNA structure, and a simplified GRN matrix model to study these questions.

Data From: Stability, Electronic, And Optical Properties Of Two-Dimensional Phosphoborane, Alexander I. Boldyrev, Nikolay Tkachenko

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The structure and properties of two-dimensional phosphoborane sheets were computationally investigated using Density Functional Theory calculations. The calculated phonon spectrum and band structure point to dynamic stability and allowed characterization of the predicted two-dimensional material as a direct-gap semiconductor with a band gap of ~1.5 eV. The calculation of the optical properties showed that the two-dimensional material has a relatively small absorptivity coefficient. The parameters of the mechanical properties characterize the two-dimensional phosphoborane as a relatively soft material, similar to the monolayer of MoS2. Assessment of thermal stability by the method of molecular dynamics indicates sufficient stability of the predicted …

Data From: All-Metal Σ-Antiaromaticity In Dimeric Cluster Anion {[Cuge9mes]2}4−, Alexander I. Boldyrev, Nikolay Tkachenko

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In this work, we report a dimeric cluster anion, {[CuGe9Mes]2}4−, which was isolated as the [K(2,2,2-crypt)]+ salt and characterized by using single-crystal X-ray diffraction and ESI mass spectroscopy. The title cluster represents the first locally σ-antiaromatic compound in the solid state, as well as the first heteroatomic antiaromatic compound.

Data From: Structure And Bonding In [Sb@In8sb12]3− And [Sb@In8sb12]5−, Alexander I. Boldyrev, Nikolay Tkachenko

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We report the characterization of the compound [K([2.2.2]crypt)]4[In8Sb13], which proves to contain a 1:1 mixture of [Sb@In8Sb12]3− and [Sb@In8Sb12]5−. The tri-anion displays perfect Th symmetry, the first completely inorganic molecule to do so, and contains eight equivalent In3+ centers in a cube. The gas-phase potential energy surface of the penta-anion has eight equivalent minima where the extra pair of electrons is localized on one In+ center, and these minima are linked by low-lying transition states where the electron pair is delocalized over two adjacent centers. The best fit to the electron density is obtained from a model where the structure …

Multifunctional Conductive Paths Obtained By Laser Processing Of Non-Conductive Carbon Nanotube/Polypropylene Composites, Federico Cesano, Mohammed Jasim Uddin, Alessandro Damin, Domenica Scarano

Chemistry Faculty Publications and Presentations

Functional materials are promising candidates for application in structural health monitoring/self-healing composites, wearable systems (smart textiles), robotics, and next-generation electronics. Any improvement in these topics would be of great relevance to industry, environment, and global needs for energy sustainability. Taking into consideration all these aspects, low-cost fabrication of electrical functionalities on the outer surface of carbon-nanotube/polypropylene composites is presented in this paper. Electrical-responsive regions and conductive tracks, made of an accumulation layer of carbon nanotubes without the use of metals, have been obtained by the laser irradiation process, leading to confined polymer melting/vaporization with consequent local increase of the nanotube …

Transactional Distances During Emergency Remote Teaching Experiences, Ma. Monica L. Moreno, Ma. Mercedes T. Rodrigo, Johanna Marion R. Torres, Timothy Jireh Gaspar, Jenilyn L. Agapito

Department of Information Systems & Computer Science Faculty Publications

The Transactional Distance Theory posits that successful remote learning occurs when teachers decrease psychological or transactional gaps. Narrowing the transactional distance can be achieved through a balance of appropriate course structure and dialogue, fostering healthy student autonomy in the process. This paper describes the Emergency Remote Teaching experiences of faculty and students of the Ateneo de Manila University in the Philippines. It examines these experiences in the context of the transactional distance framework. Findings show that a sudden shift to remote learning mandates greater student autonomy, which increases transactional distance. Because of this, efforts by faculty to increase student-teacher dialogue …

Structure, Neutrostructure, And Antistructure In Science, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

In any science, a classical Theorem, defined on a given space, is a statement that is 100% true (i.e. true for all elements of the space). To prove that a classical theorem is false, it is sufficient to get a single counter-example where the statement is false. Therefore, the classical sciences do not leave room for partial truth of a theorem (or a statement). But, in our world and in our everyday life, we have many more examples of statements that are only partially true, than statements that are totally true. The NeutroTheorem and AntiTheorem are generalizations and alternatives of …

Computational Analysis Of Large-Scale Trends And Dynamics In Eukaryotic Protein Family Evolution, Joseph Boehm Ahrens

FIU Electronic Theses and Dissertations

The myriad protein-coding genes found in present-day eukaryotes arose from a combination of speciation and gene duplication events, spanning more than one billion years of evolution. Notably, as these proteins evolved, the individual residues at each site in their amino acid sequences were replaced at markedly different rates. The relationship between protein structure, protein function, and site-specific rates of amino acid replacement is a topic of ongoing research. Additionally, there is much interest in the different evolutionary constraints imposed on sequences related by speciation (orthologs) versus sequences related by gene duplication (paralogs). A principal aim of this dissertation is to …

Magnetic Exploration Of The Crescent Formation, Washington: The Search For A Hidden Fault Near Dusk Point, Samuel G. Furmanski

Summer Research

The mafic rocks of the Olympic Peninsula, Washington, are part of an accreted terrane known as Siletzia which experienced transpressional stresses as far as 50 Ma ago in the early Eocene. The Peninsula has an accretion-thrust marine sedimentary interior and a mafic volcanic periphery juxtaposed along the Hurricane Ridge fault; a terrane-scale thrust fault. The mafic Crescent Formation (CF) can be subdivided into two units: The Lower Crescent member (LC) and the Upper Crescent member (UC) as defined by Tabor and Cady (1978). The LC consists of submarine basalt flows that have composition similar to mid-oceanic ridges with zircon fission-track …

Electronic Structure Engineering Of Licoo2 Toward Enhanced Oxygen Electrocatalysis, Xiaobo Zheng, Yaping Chen, Xusheng Zheng, Guoqiang Zhao, Kun Rui, Peng Li, Xun Xu, Zhenxiang Cheng, Shi Xue Dou, Wenping Sun

Australian Institute for Innovative Materials - Papers

Developing low-cost and efficient electrocatalysts for the oxygen evolution reaction and oxygen reduction reaction is of critical significance to the practical application of some emerging energy storage and conversion devices (e.g., metal-air batteries, water electrolyzers, and fuel cells). Lithium cobalt oxide is a promising nonprecious metal-based electrocatalyst for oxygen electrocatalysis; its activity, however, is still far from the requirements of practical applications. Here, a new LiCoO 2 -based electrocatalyst with nanosheet morphology is developed by a combination of Mg doping and shear force-assisted exfoliation strategies toward enhanced oxygen reduction and evolution reaction kinetics. It is demonstrated that the coupling effect …

Structure And Electrochemical Performance Modulation Of A Lini0.8co0.1mn0.1o2 Cathode Material By Anion And Cation Co-Doping For Lithium Ion Batteries, Rong Li, Yong Ming, Wei Xiang, Chunliu Xu, Guilin Feng, Yongchun Li, Yanxiao Chen, Zhenguo Wu, Ben-He Zhong, Xiaodong Guo

Australian Institute for Innovative Materials - Papers

Ni-rich layered transition metal oxides show great energy density but suffer poor thermal stability and inferior cycling performance, which limit their practical application. In this work, a minor content of Co and B were co-doped into the crystal of a Ni-rich cathode (LiNi0.8Co0.1Mn0.1O2) using cobalt acetate and boric acid as dopants. The results analyzed by XRD, TEM, XPS and SEM reveal that the modified sample shows a reduced energy barrier for Li+ insertion/extraction and alleviated Li+/Ni2+ cation mixing. With the doping of B and Co, corresponding enhanced cycle stability was achieved with a high capacity retention of 86.1% at 1.0C …

The Effect Of Curing And Zirconium Content On The Wettability And Structure Of A Silicate Hybrid Sol-Gel Material, Emma Machugh, Maikki Cullen, Alicja Kaworek, Brendan Duffy, Mohamed Oubaha

Articles

Functional hybrid sol-gel coatings have been developed for numerous applications with a wide range of wettabilities. This study proposes to investigate the relationship between the structure and the wetting properties of a zirconium modified silicate hybrid sol-gel coating. The structures of the coatings were altered by varying the content of zirconium, and the curing process, while keeping the sol-gel preparation conditions identical. The structure of the materials was characterized by FTIR, 29Si NMR and SEM. The thermal properties and the wettability are identified by DSC and contact angle measurements, respectively. By corroborating the structural and wettability analyses, it is shown …

Phonon Dynamics Of Alkali Metals In The Hcp Lattice Structure, Jake Christensen

Physics Capstone Projects

An Embedded-Atom-Method model that is successful at describing the vibrational properties of alkali metals in the BCC crystal structure is applied to the HCP structure. Phonon dispersion curves, density of states, and Debye temperatures are calculalated for Li, Na, K, Rb, and Cs. Comparison of BCC, FCC and HCP Debye temperatures show that BCC is the preferred structure at higher temperatures, which agrees with experiment.

The Role Of The Hydrolysis And Zirconium Concentration On The Structure And Anticorrosion Performances Of A Hybrid Silicate Sol-Gel Coating, Maikki Cullen, Mary O’Sullivan, Aditya Madhan Kumar, Ahmad A. Sorour, Brendan Duffy, Mohamed Oubaha

Articles

In sol-gel chemistry, hydrolysis is the key step in the formation of the reactive hydroxide groups that are responsible for the formation of inorganic networks via the occurrence of condensation reactions. Though previous studies have investigated the effect of the hydrolysis conditions on the structure of organically modified silicates (ormosils), no study, to our knowledge, has investigated this variable on the structure of hybrid materials prepared by combinations of an ormosil and a transition metal (TM). Here, we propose to investigate this effect in a hybrid material composed of 3-trimethoxysilylpropylmethacrylate and a zirconium complex. To also highlight the effects of …

An Investigation Of Atomic Structures Derived From X-Ray Crystallography And Cryo-Electron Microscopy Using Distal Blocks Of Side-Chains, Lin Chen, Jing He, Salim Sazzed, Rayshawn Walker

Computer Science Faculty Publications

Cryo-electron microscopy (cryo-EM) is a structure determination method for large molecular complexes. As more and more atomic structures are determined using this technique, it is becoming possible to perform statistical characterization of side-chain conformations. Two data sets were involved to characterize block lengths for each of the 18 types of amino acids. One set contains 9131 structures resolved using X-ray crystallography from density maps with better than or equal to 1.5 Å resolutions, and the other contains 237 protein structures derived from cryo-EM density maps with 2-4 Å resolutions. The results show that the normalized probability density function of block …

Bioinformatic And Biophysical Analyses Of Proteins, Jonathan Catazaro

Department of Chemistry: Dissertations, Theses, and Student Research

The prevailing dogma in structural genomics is the existence of a strong correlation between protein sequence, structure, and biological function. Proteins with high sequence similarity typically have a similar, if not the same, structure and function. In many cases this logic can fail due to distantly related proteins having very low sequence similarity, a lack of a representative structure, structural novelty, or the absence of a characterized function. Further, the paradigm fails to account for dynamics, which have a significant effect on structural stability and enzymatic efficacy.

Nuclear magnetic resonance (NMR) spectroscopy is uniquely capable of solving the structure, assisting …

Milky Way Tomography With K And M Dwarf Stars: The Vertical Structure Of The Galactic Disk, Deborah Ferguson, Susan Gardner, Brian Yanny

Physics and Astronomy Faculty Publications

We use the number density distributions of K and M dwarf stars with vertical height from the Galactic disk, determined using observations from the Sloan Digital Sky Survey, to probe the structure of the Milky Way disk across the survey's footprint. Using photometric parallax as a distance estimator we analyze a sample of several million disk stars in matching footprints above and below the Galactic plane, and we determine the location and extent of vertical asymmetries in the number counts in a variety of thin- and thick-disk subsamples in regions of some 200 square degrees within 2 kpc in vertical …

Mechanism-Informed Refinement Reveals Altered Substrate-Binding Mode For Catalytically Competent Nitroreductase, Warintra Pitsawong, Chad A. Haynes, Ronald L. Koder, David W. Rodgers, Anne-Frances Miller

Chemistry Faculty Publications

Nitroreductase from Enterobacter cloacae (NR) reduces diverse nitroaromatics including herbicides, explosives and prodrugs, and holds promise for bioremediation, prodrug activation and enzyme-assisted synthesis. We solved crystal structures of NR complexes with bound substrate or analog for each of its two half-reactions. We complemented these with kinetic isotope effect (KIE) measurements elucidating H-transfer steps essential to each half-reaction. KIEs indicate hydride transfer from NADH to the flavin consistent with our structure of NR with the NADH analog nicotinic acid adenine dinucleotide (NAAD). The KIE on reduction of p-nitrobenzoic acid (p-NBA) also indicates hydride transfer, and requires revision of …

Plant Diversity Influences The Structure And Function Of A Restored Prairie And Its Responses To Added Disturbances, Rebecca Bevans

School of Natural Resources: Dissertations, Theses, and Student Research

As global warming, human conversion of natural landscapes to agricultural uses, and widespread biodiversity losses continue to alter the ecosystems we depend on, an understanding of the relationship between ecosystem structure, composition, and function is needed to maintain valuable ecosystem states and their associated functions. Research testing the limits of an ecosystem’s ability to maintain essential structure and functioning under disturbance conditions can aid in this goal.

In this study, I measured the relationship between plant diversity, community structure and functional traits, and their responses to added disturbances. I added disturbances representing those either caused or intensified by human activity …

Correlation Between The Structure And The Anticorrosion Barrier Properties Of Hybrid Sol–Gel Coatings: Application To The Protection Of Aa2024-T3 Alloys, Maikki Cullen, Muhammad Morshed, Mary O'Sullivan, Emma Mchugh, Brendan Duffy, Mohamed Oubaha

Articles

Hybrid sol–gel materials have been extensively studied as viable alternatives to toxic chromate (VI)-based coatings for the corrosion protection of AA2024-T3 in the aerospace industry, due to the wide range of available chemistries they offer and the tremendous development potential of innovative functional coatings. However, so far, little work has been performed in identifying the effect of the employed chemistries on the structure and anticorrosion properties of the coatings. This work proposes to contribute to a better understanding of the relationship existing between the structure, morphology and anticorrosion properties of hybrid sol–gel coatings deposited on AA2024- T3 aluminium surfaces, the …

Amalgam+: Composing Rich Information Sources For Accurate Bug Localization, Shaowei Wang, David Lo

Research Collection School Of Computing and Information Systems

During the evolution of a software system, a large number of bug reports are submitted. Locating the source code files that need to be fixed to resolve the bugs is a challenging problem. Thus, there is a need for a technique that can automatically figure out these buggy files. A number of bug localization solutions that take in a bug report and output a ranked list of files sorted based on their likelihood to be buggy have been proposed in the literature. However, the accuracy of these tools still needs to be improved. In this paper, to address this need, …

Slides: The Columbia River Basin, Barbara Cosens

Coping with Water Scarcity in River Basins Worldwide: Lessons Learned from Shared Experiences (Martz Summer Conference, June 9-10)

Presenter: Barbara Cosens, Professor and Associate Dean of Faculty, University of Idaho College of Law, Waters of the West Interdisciplinary Program

16 slides

Structure Symmetry Determination And Magnetic Evolution In Sr2Ir1−XRhXO4, Feng Ye, Xiaoping Wang, Christina Hoffmann, Jinchen Wang, Songxue Chi, Masaaki Matsuda, Bryan C. Chakoumakos, Jaime A. Fernandez-Baca, Gang Cao

Physics and Astronomy Faculty Publications

We use single-crystal neutron diffraction to determine the crystal structure symmetry and the magnetic evolution in the rhodium-doped iridates Sr₂Ir_1−xRh_xO₄ (0≤ x ≤ 0.16). Throughout this doping range, the crystal structure retains a tetragonal symmetry (space group I4₁/a) with two distinct magnetic Ir sites in the unit cell forming staggered IrO₆ rotation. Upon Rh doping, the magnetic order is suppressed and the magnetic moment of Ir⁴⁺ is reduced from 0.21μ_B/Ir for x=0 to 0.18μ_B/Ir for x=0.12. The magnetic structure …

Guidelines For Good Mathematical Writing, Francis Su

All HMC Faculty Publications and Research

Communicating mathematics well is an important part of doing mathematics. Many of us know from writing papers or giving talks that communicating effectively not only serves our audience but also clarifies and structures our own thinking. There is an art and elegance to good writing that every writer should strive for. And writing, as a work of art, can bring a person great personal satisfaction.

Within the MAA, we value exposition and mathematical communication. In this column, I’m sharing the advice I give my students to help them write well. There are more extensive treatments (e.g., see Paul Halmos’s How …

Moments Of The Neutron G2 Structure Function At Intermediate Q2, Wolfgang Korsch, P. Solvignon, N. Liyanage, J.-P. Chen, Seonho Choi, K. Slifer, K. Aniol, T. Averett, W. Boeglin, A. Camsonne, G. D. Cates

Physics and Astronomy Faculty Publications

We present new experimental results for the ³He spin structure function g₂ in the resonance region at Q² values between 1.2 and 3.0(GeV/c)². Spin dependent moments of the neutron were extracted. Our main result, the inelastic contribution to the neutron d₂ matrix element, was found to be small at ⟨Q²⟩=2.4(GeV/c)² and in agreement with the lattice QCD calculation. The Burkhardt-Cottingham sum rule for ³He and the neutron was tested with the measured data and using the Wandzura-Wilczek relation for the low x unmeasured region.

Star Formation And Quenching Among The Most Massive Galaxies At Z ∼ 1.7, C. Mancini, A. Renzini, E. Daddi, G. Rodighiero, S. Berta, N. Grogin, Dale D. Kocevski, A. Koekemoer

Physics and Astronomy Faculty Publications

We have conducted a detailed object-by-object study of a mass-complete (M_* ≥ 10¹¹ M_⊙) sample of 56 galaxies at 1.4 ≤ z ≤ 2 in the Great Observatories Origins Deep Survey-South field, showing that an accurate deblending in 24 μm images is essential to properly assign to each galaxy its own star formation rate (SFR), whereas an automatic procedure often fails. This applies especially to galaxies with SFRs below the main sequence (MS) value, which may be in their quenching phase. After that, the sample splits evenly between galaxies forming stars within a factor of …

P-Manga: Full Spectral Fitting And Stellar Population Maps From Prototype Observations, David M. Wilkinson, Claudia Maraston, Daniel Thomas, Lodovico Coccato, Rita Tojeiro, Michele Cappellari, Francesco Belfiore, Matthew Bershady, Mike Blanton, Kevin Bundy, Sabrina Cales, Brian Cherinka, Niv Drory, Eric Emsellem, Hai Fu, David Law, Cheng Li, Roberto Maiolino, Karen Masters, Christy Tremonti, David Wake, Enci Wang, Anne-Marie Weijmans, Ting Xiao, Renbin Yan, Kai Zhang, Dmitry Bizyaev, Jonathan Brinkmann, Karen Kinemuchi, Daniel Oravetz, Kaike Pan, Audrey Simmons

Physics and Astronomy Faculty Publications

MaNGA (Mapping Nearby Galaxies at Apache Point Observatory) is a 6-yr SDSS-IV (Sloan Digital Sky Survey IV) survey that will obtain resolved spectroscopy from 3600 to 10 300 Å for a representative sample of over 10 000 nearby galaxies. In this paper, we derive spatially resolved stellar population properties and radial gradients by performing full spectral fitting of observed galaxy spectra from P-MaNGA, a prototype of the MaNGA instrument. These data include spectra for 18 galaxies, covering a large range of morphological type. We derive age, metallicity, dust, and stellar mass maps, and their radial gradients, using high spectral-resolution stellar …