Chemistry Commons^™

Observation Of The Low-Frequency Spectrum Of The Water Trimer As A Sensitive Test Of The Water-Trimer Potential And The Dipole-Moment Surface, Raffael Schwan, Chen Qu, Devendra Mani, Nitish Pal, Gerhard Schwaab, Joel M. Bowman, Gregory S. Tschumper, Martina Havenith

Chemistry Faculty Research & Creative Works

Intermolecular interactions in bulk water are dominated by pairwise and non-pairwise cooperative interactions. While accurate descriptions of the pairwise interactions are available and can be tested by precise low-frequency spectra of the water dimer up to 550 cm−1, the same does not hold for the three-body interactions. Here, we report the first comprehensive spectrum of the water trimer in the frequency region from 70 to 620 cm−1 using helium-nanodroplet isolation and free-electron lasers. By comparison to accompanying high-level quantum calculations, the experimentally observed intermolecular bands can be assigned. The transition frequencies of the degenerate translation, the degenerate in-plane and the …

Nobiletin Affects Circadian Rhythms And Oncogenic Characteristics In A Cell-Dependent Manner, Sujeewa S. Lellupitiyage Don, Kelly L. Robertson, Hui-Hsien Lin, Caroline Labriola, Mary E. Harrington, Stephanie R. Taylor, Michelle E. Farkas

Psychology: Faculty Publications

The natural product nobiletin is a small molecule, widely studied with regard to its therapeutic effects, including in cancer cell lines and tumors. Recently, nobiletin has also been shown to affect circadian rhythms via their enhancement, resulting in protection against metabolic syndrome. We hypothesized that nobiletin’s anti-oncogenic effects, such as prevention of cell migration and formation of anchorage independent colonies, are correspondingly accompanied by modulation of circadian rhythms. Concurrently, we wished to determine whether the circadian and anti-oncogenic effects of nobiletin differed across cancer cell lines. In this study, we assessed nobiletin’s circadian and therapeutic characteristics to ascertain whether these …

Integrated Approaches To Reveal Mechanisms By Which Rna Viruses Reprogram The Cellular Environment, Christina Haddad, Jesse Davila-Calderon, Blanton S. Tolbert

Faculty Scholarship

RNA viruses are major threats to global society and mass outbreaks can cause long-lasting damage to international economies. RNA and related retro viruses represent a large and diverse family that contribute to the onset of human diseases such as AIDS; certain cancers like T cell lymphoma; severe acute respiratory illnesses as seen with COVID-19; and others. The hallmark of this viral family is the storage of genetic material in the form of RNA, and upon infecting host cells, their RNA genomes reprogram the cellular environment to favor productive viral replication. RNA is a multifunctional biomolecule that not only stores and …

Influence Of The Nature Of The Medium On The Conformational States Of Macromolecules Of Anionic Polyelectrolytes And Their Flocculating Effect, Mapruza Dzhumamuratova, Amanbay Pirniyazov, Oleg Dormeshkin, Akhmed Reymov, Tleumuratov Kuanish, Saparbay Kalbaev

Karakalpak Scientific Journal

The properties of surfactants of anionic polyelectrolytes are investigated depending on the nature of the medium, conformational states neutralized by organic bases, differing in the length of the hydrocarbon radical. The concept of the role of the state of macromolecules in solution in the indicated processes has been developed. The anionic carboxyl-containing polyelectrolytes synthesized on the basis of methacrylic acid differed not only in the length of the hydrocarbon radical of the organic base - counterion, but also in their branching. The relationship between the state of polyelectrolyte macromolecules in solution and their ability to regulate the properties of natural …

A Diverse View Of Science To Catalyse Change, César A. Urbina-Blanco, Safia Z. Jilani, Isaiah R. Speight, Michael J. Bojdys, Tomislav Friščić, J. Fraser Stoddart, Toby L. Nelson, James Mack, Renã A.S. Robinson, Emanuel A. Waddell, Jodie L. Lutkenhaus, Murrell Godfrey, Martine I. Abboud, Stephen O. Aderinto, Damilola Aderohunmu, Lučka Bibič, João Borges, Vy M. Dong, Lori Ferrins, Fun Man Fung, Torsten John, Felicia P. L. Lim, Sarah L. Masters, Dickson Mambwe, Pall Thordarson, Maria Magdalena Titirici, Gabriela D. Tormet-González, Miriam M. Unterlass, Austin Wadle, Vivian W. W. Yam, Ying Wei Yang

Faculty and Student Publications

© 2020 Croatian Chemical Society. All rights reserved. Valuing diversity leads to scientific excellence, the progress of science and, most importantly, it is simply the right thing to do. We must value diversity not only in words, but also in actions.

Synthesis Of Cds/Zns Core/Shell Semiconductor Nanoparticles, Austin Skyler Antle

Masters Theses & Specialist Projects

Core/shell semiconductor nanoparticles are of great interest as photocatalysts due to their large surface area per volume and tunable band gaps. The synthesis of core/shell semiconductor nanoparticles has traditionally involved the use of binding ligands to ensure the particles do not aggregate. These binding ligands lower the surface area of the nanoparticles though, reducing their overall efficiency. Ionic liquids have been found to be capable of acting as both solvents and stabilizing agents for synthesis of catalysts with highly active surfaces. Our experiments focus on the synthesis of CdS/ZnS core/shell nanoparticles with the ionic liquid 1-butyl-3-methylimidazolium methyl sulfate, [BMIM][MeSO4], acting …

Solvent-Free Synthesis Of Metal Coordination Compounds Using Ball Mills, Jenna Cantway

Masters Theses & Specialist Projects

Mechanochemistry utilizes mechanical energy to promote chemical reactions to completion. Samples ground with a ball mill are placed under consistent pressure and temperature, which allows for increased surface area, shorter reaction times and overall better control of reaction conditions compared to the use of a mortar and pestle. Many synthetic techniques to prepare metal coordination compounds use a solvent. The solvent promotes the reactions by providing a route for reagents to interact. While solvents facilitate reactions, there is interest in reducing or eliminating solvents altogether during the synthesis process due to potential instability of a solvent under certain experimental conditions …

Radiocarbon And Contextual Data For Non Nok Tha, Don Kok Pho And Don Pa Daeng, Khon Kaen Province, Northeast Thailand, Cyler N. Conrad, Eden Franz, Ernestene Green, Emily Lena Jones

Anthropology Datasets

This compendium includes ten documents: 1) the "Buckley Letter" describing the radiocarbon analysis results for sample I-5324, 2) the "GaK-653" sheet describing the radiocarbon analysis results for sample GaK-653, 3) the "GaK-1026" sheet describing the radiocarbon analysis results for sample GaK-1026, 4) the "Geochron Letter" describing radiocarbon analysis results for sample GX-1612, 5) Ernestene Green's ca. 1965 field notes on her test excavations at Don Kok Pho (NP6), 6) Ernestene Green's ca. 1965 field notes on her test excavations at Non Nok Tha (NP7), 7) Ernestene Green's ca. 1965 field notes on her test excavations at Don Pa Daeng (NP8), …

California - Cottonwood Weigh Station, University Of Denver

On-road Heavy-duty Monitoring System Measurements

Relevant Publications

Environmental Science & Technology Publication (2015)

Environmental Science & Technology Publication (2017)

Environmental Science & Technology Publication (2018)

Final Report

California - Port Of Los Angeles, Unversity Of Denver

On-road Heavy-duty Monitoring System Measurements

Relevant Publications

Environmental Science & Technology Publication (2015)

Environmental Science & Technology Publication (2017)

Environmental Science & Technology Publication (2018)

Final Report

Glyoxal’S Impact On Dry Ammonium Salts: Fast And Reversible Surface Aerosol Browning, David O. De Haan Phd, Lelia N. Hawkins Phd, Kevin Jansen, Hannah G. Welsh, Raunak Pednekar, Alexia De Loera, Natalie G. Jimenez, Margaret A. Tolbert Phd, Mathieu Cazaunau Phd, Aline Gratien, Antonin Bergé, Edouard Pangui, Paola Formenti, Jean-François Doussin

Chemistry and Biochemistry: Faculty Scholarship

Alpha-dicarbonyl compounds are believed to form brown carbon in the atmosphere via reactions with ammonium sulfate (AS) in cloud droplets and aqueous aerosol particles. In this work, brown carbon formation in AS and other aerosol particles was quantified as a function of relative humidity (RH) during exposure to gas-phase glyoxal (GX) in chamber experiments. Under dry conditions (RH < 5%), solid AS, AS/glycine, and methylammonium sulfate aerosol particles brown within minutes upon exposure to GX, while sodium sulfate particles do not. When GX concentrations decline, browning goes away, demonstrating that this dry browning process is reversible. Declines in aerosol albedo are found to be a function of [GX]², and are consistent between AS and AS/glycine aerosol. Dry methylammonium sulfate aerosol browns 4´ more than dry AS aerosol, but deliquesced AS aerosol browns much less than dry AS aerosol. Optical measurements at 405, 450, and 530 nm provide an …

Asp Diversity And Inclusion Committee Call To Action, Nadja Cech, Christine Salomon, Susan Mooberry, Sandra Loesgen, Katharine Watts, Josh Kellogg, Lesley Ann Giddings, Brian T. Murphy, Esther A. Guzmán

Chemistry: Faculty Publications

No abstract provided.

Soil Labile Organic Carbon Fractions And Soil Enzyme Activities After 10 Years Of Continuous Fertilization And Wheat Residue Incorporation, Ligan Zhang, Xi Chen, Yujun Xu, Mengcan Jin, Xinxin Ye, Hongjian Gao, Wenying Chu, Jingdong Mao, Michael L. Thompson

Chemistry & Biochemistry Faculty Publications

Labile organic carbon (LOC) fractions and related enzyme activities in soils are considered to be early and sensitive indicators of soil quality changes. We investigated the influences of fertilization and residue incorporation on LOC fractions, enzyme activities, and the carbon pool management index (CPMI) in a 10-year field experiment. The experiment was composed of three treatments: (1) no fertilization (control), (2) chemical fertilizer application alone (F), and (3) chemical fertilizer application combined with incorporation of wheat straw residues (F + R). Generally, the F + R treatment led to the highest concentrations of the LOC fractions. Compared to the control …

Disinfection Byproduct Drivers Of Cytotoxicity In Drinking Water And Swimming Pools, Joshua M. Allen

Theses and Dissertations

Water disinfection was cited as the greatest public health achievement of the 20th Century. By inactivating pathogens, disinfection has significantly reduced waterborne diseases in drinking water and swimming pools. However, chemical disinfection has also raised a public health issue: the potential for cancer induction, reproductive and developmental effects, and asthma-related risks associated with exposure to chemical disinfection byproducts (DBPs), which are formed by the reaction of disinfectants with organic matter (natural or anthropogenic), bromide, and iodide. In the U.S., four trihalomethanes (THMs) and five haloacetic acids (HAAs) are currently regulated in drinking water, although no DBPs are regulated in pools, …

Probing Cooperativity In C–H⋯N And C–H⋯Π Interactions: Dissociation Energies Of Aniline⋯(Ch4)N (N = 1, 2) Van Der Waals Complexes From Resonant Ionization And Velocity Mapped Ion Imaging Measurements, James Makuvaza, John L. Loman, Damian L. Kokkin, Scott A. Reid

Chemistry Faculty Research and Publications

Recent studies of the weakly bound anisole⋯CH₄ complex found a dual mode of binding, featuring both C/H⋯π and C/H⋯O noncovalent interactions. In this work, we examine the dissociation energies of related aniline⋯(CH₄)_n (n = 1, 2) van der Waals clusters, where both C/H⋯π and C/H⋯N interactions are possible. Using a combination of theory and experiments that include mass-selected two-color resonant two-photon ionization spectroscopy, two-color appearance potential (2CAP) measurements, and velocity-mapped ion imaging (VMI), we derive the dissociation energies of both complexes in the ground (S₀), excited (S₁), and cation radical (D …

Understanding The Interfacial Reactions Initiating On Lithium Metal Surfaces In Next-Generation Battery Technologies, Joshua A. Lochala

Graduate Theses and Dissertations

Li-ion batteries have started to reach the theoretical maximum energy. Next-generation batteries represent the future of portable energy sources for vehicle electrification and grid energy storage. Li metal battery is one of the most promising next-generation battery technologies that could potentially double the cell-level energy of conventional Li-ion batteries. However, Li metal has multiple drawbacks that require addressing before realization. These drawbacks include dendrite formation leading to internal short and increasing internal resistance due to the breakdown of electrolyte, leading to rapid cell death. These problems stem from the interfacial reactions occurring during the plating and stripping of Li metal. …

Crystal Structure Of N,N-Diiso­Propyl-4-Methyl­Benzene­Sulfonamide, Brock A. Stenfors, Richard J. Staples, Shannon Biros, Felix Ngassa

Open Access Publishing Support Funded Articles

The synthesis of the title compound, C13H21NO2S, is reported here along with its crystal structure. This compound crystallizes with two mol­ecules in the asymmetric unit. The sulfonamide functional group of this structure features S=O bond lengths ranging from 1.433 (3) to 1.439 (3) Å, S—C bond lengths of 1.777 (3) and 1.773 (4) Å, and S—N bond lengths of 1.622 (3) and 1.624 (3) Å. When viewing the mol­ecules down the S—N bond, the isopropyl groups are gauche to the aromatic ring. On each mol­ecule, two methyl hydrogen atoms of one isopropyl group are engaged in intra­molecular C—H⋯O hydrogen bonds …

Crystal Structure Of 4-Methyl-N-Propyl­Benzene­Sulfonamide, Brock A. Stenfors, Rachel C. Collins, Jonah R.J. Duran, Shannon Biros, Felix Ngassa

Open Access Publishing Support Funded Articles

The crystal structure of the title sulfonamide, C₁₀H₁₅NO₂S, comprises two mol­ecules in the asymmetric unit. The S=O bond lengths of the sulfonamide functional group range from 1.428 (2) to 1.441 (2) Å, with S—C bond lengths of 1.766 (3) Å (for both mol­ecules in the asymmetric unit), and S—N bond lengths of 1.618 (2) and 1.622 (3) Å, respectively. When both mol­ecules are viewed down the N—S bond, the propyl group is gauche to the toluene moiety. In the crystal structure, mol­ecules of the title compound are arranged in an intricate three-dimensional network that …

Mqct: User-Ready Program For Calculations Of Inelastic Scattering Of Two Molecules, Alexander Semenov, Bikramaditya Mandal, Dmitri Babikov

Chemistry Faculty Research and Publications

A program named MQCT is developed for calculations of rotationally and vibrationally inelastic scattering of molecules using the mixed quantum/classical theory approach. Calculations of collisions between two general asymmetric top rotors are now possible, which is a feature unavailable in other existing codes. Vibrational states of diatomic molecules can also be included in the basis set expansion, to carry out calculations of ro-vibrational excitation and quenching. Minimal input for the code assumes several defaults and is very simple, easy to set-up and run by non-experts. Multiple options, available for expert calculations, are listed in the Supplemental Information. The code is …

Thiophene Derivative Monomers Co-Electropolymerized On Microelectrodes Within Arrays For Tailored Surface Chemistry And Electrochemical Properties, Benjamin J. Jones

Graduate Theses and Dissertations

Potentiodynamic co-electropolymerization of two thiophene derivatives, (2,3-dihydrothieno[3,4-b]dioxin-2-yl)methanol (1) and 4-((2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)-methoxy)-4-oxobutanoic acid (2), in aqueous solutions (0.02 M total monomer, 0.05 M sodium dodecyl sulfate (SDS) and 0.1 M LiClO4) on gold microband electrodes in an array was investigated. A modified Steglich esterification reaction between monomer 1 and succinic anhydride produced monomer 2 at 93.6% yield. Seven deposition solutions of the two monomers, defined by mol% of monomer 2 (0, 25, 34, 50, 66, 75, 100) generated seven sets of polymer films by cyclic voltammetry in a specially designed cell to conserve monomer. The onset potential for monomer oxidation and total …

The Recreation Of Wound Patterns Using Various Tissue Simulants For Crime Scene Reconstruction, Breanne Steimle

Forensic Science Master's Projects

Within the field of forensic science, there are limited reliable methods for the simulation of pattern injuries on human skin and tissue that may aid in aspects of crime scene reconstruction. The tissue simulant must be of sufficient integrity for recording blunt force trauma and bite mark impressions, electrocution, cutting, and gunshot wound related injuries for the purpose of re-enactment, court exhibition, and distance determination. For wound reenactments (such as blunt force trauma, bite mark impressions and electrocution), dead skin and tissue from human cadavers do not show wounding patterns that would occur on live tissue. This study examines different …

Three-Event Energy Detection With Adaptive Threshold For Spectrum Sensing In Cognitive Radio Systems, Alexandru Martian, Mahmood Jalal Ahmad Al Sammarraie, Calin Vladeanu, Dimitrie Popescu

Electrical & Computer Engineering Faculty Publications

Implementation of dynamic spectrum access (DSA) in cognitive radio (CR) systems requires the unlicensed secondary users (SU) to implement spectrum sensing to monitor the activity of the licensed primary users (PU). Energy detection (ED) is one of the most widely used methods for spectrum sensing in CR systems, and in this paper we present a novel ED algorithm with an adaptive sensing threshold. The three-event ED (3EED) algorithm for spectrum sensing is considered for which an accurate approximation of the optimal decision threshold that minimizes the decision error probability (DEP) is found using Newton’s method with forced convergence in one …

Investigation Of Evidence For The Internal Structure Of A Modified Science Motivation Questionnaire Ii (Msmq Ii): A Failed Attempt To Improve Instrument Functioning Across Course, Subject, And Wording Variants, Regis Komperda, Kathryn Hosbein, Michael M. Phillips, Jack Barbera

Chemistry Faculty Publications and Presentations

The Science Motivation Questionnaire II (SMQ II) was developed to measure aspects of student motivation in college-level science courses. Items on the SMQ II are structured such that the word ‘science’ can be replaced with any discipline title (e.g., chemistry) to produce a discipline-specific measure of student motivation. Since its original development as the Science Motivation Questionnaire and subsequent refinement, the SMQ II and its discipline-specific variants have been used in a number of science education studies. However, many studies have failed to produce acceptable validity evidence for their data based on the proposed internal structure of the …

Comparison Of Chemotherapeutic Activities Of Rhodamine-Based Gumbos And Nanogumbos, Nimisha Bhattarai, Mi Chen, Rocío L. Pérez, Sudhir Ravula, Robert Strongin, Karen Mcdonough, Isiah M. Warner

Chemistry Faculty Publications and Presentations

Rhodamine derivatives have been widely investigated for their mitochondrial targeting and chemotherapeutic properties that result from their lipophilic cationic structures. In previous research, we have found that conversion of Rhodamine 6G into nanoGUMBOS, i.e., nanomaterials derived from a group of uniform materials based on organic salts (GUMBOS), led to selective chemotherapeutic toxicity for cancer cells over normal cells. Herein, we investigate the chemotherapeutic activity of GUMBOS derived from four different rhodamine derivatives, two bearing an ester group, i.e., Rhodamine 123 (R123) and SNAFR-5, and two bearing a carboxylic acid group, i.e., rhodamine 110 (R110) and rhodamine B (RB). In this …

Synthesis And Evaluation Of Small Molecule Inhibitors Of Pyruvate Carboxylase, Daniel John Burkett

Master's Theses (2009 -)

Through structure-based drug design (SBDD), a series of small molecules have been synthesized and evaluated for inhibitory activity against the pyruvate carboxylase (PC) enzyme via two biological assays. The -hydroxycinnamic acid scaffold was identified as the most privileged scaffold for inhibition of PC. Analogues of phenylpyruvic acid were generated and evaluated, leading to the discovery of inhibitors with single digit micromolar (M) IC50 values. The most potent inhibitors identified were evaluated for inhibitory activity against other metalloproteins, and 2-hydroxy-3-(quinolone-2-yl)propenoic acid did not significantly inhibit human carbonic anhydrase II, matrix metalloproteinase-2, malate dehydrogenase, or lactate dehydrogenase. The small molecules presented in …

The Rotational Spectrum Of 1,1-Diiodoethane, Michael Joseph Carrillo

Theses and Dissertations

The first chapter of this thesis introduces the basic theory of rotational spectroscopy. This includes the theory of a rigid rotor, centrifugal distortion, and hyperfine effects. The theory behind diatomic systems is explained first, and then expanded to the asymmetric top system. The second chapter encompasses a brief overview on the development of microwave spectroscopy and discusses the instruments that were utilized during this study, namely the cavity-based and chirped-pulse Fourier transform microwave spectrometers. Chapter three describes the quantum chemical calculation methods and basis sets that were applied throughout this study. Chapter four discusses the progress of data analysis of …

Exploratory Molten Flux Crystal Growth Of Complex Uranium Oxides, Christian A. Juillerat

Theses and Dissertations

While the use of nuclear technology has proven useful for energy generation and for military use, the proper disposal and storage of the resulting nuclear waste requires serious attention to ensure radioactive species are indefinitely sequestered to protect the biosphere. There are several classifications of nuclear waste such as spent nuclear fuel (from industrial power plants), low level waste (slightly contaminated trash), and high level waste (HLW) which is in the form of a sludge, precipitated salt, or liquid. Each of these requires a different approach to processing and storage. Of these, HLW requires the most attention because it is …

Thermotropic And Lyotropic Phase Behaviours Of Spontaneously Self-Assembled Amphiphilic Branched-Chain Glycosides With Various Chain Length, Abdul Hamid Hairul Amani

Student Works (2020-2029)

Lipid polymorphism is a process which illustrates the self-assembly of lipid aggregation depending on the environment. Lipids such as branched-chain glycolipids which are amphiphilic molecules also known as amphitropic tend to generate mesophases in thermotropic (dry) and lyotropic (solvation) conditions. These molecules are capable of self-aggregating into various types of glycolipid self-assemblies offering an interesting insight in relation to their functions in living cells. Hence, this study aims to investigate the mesophases of ꞵ-D-glycosides which are branched-chain synthetic glycolipids, namely, ꞵ-D-glucosides and ꞵ-D-maltosides. The study was carried out on the thermotropic phases of dry glycosides and the lyotropic phases of …

Optimisation Of Biomass And Lipid Production Of A Tropical Thraustochytrid Aurantiochytrium Sp. Umacc-T023 In Submerged-Liquid Fermentation For Large-Scale Biodiesel Production, Sohedein Mohamad Nor Azzimi

Student Works (2020-2029)

A tropical thraustochytrid, Aurantiochytrium sp. UMACC-T023, was optimised for high biomass and lipid production in submerged-liquid fermentation (SLF). Biomass and lipid production were optimised based on glucose, polypeptone, and yeast extract concentration using response surface methodology (RSM). In RSM, the applied central composite design (CCD) showed that the optimisation model was significant for all variables studied. Yeast extract and polypeptone were associated with significant effects in UMACC-T023 biomass production with p < 0.05. The model was validated by employing the optimised media composition in shake flasks and in 1.4-L stirred-tank bioreactors. The optimised media composition for both biomass and lipid production was 10 g L-1 glucose, 15.08 g L-1 polypeptone, and 13.56 g L-1 yeast extract. Biomass production in the bioreactor increased 2.12-fold compared with the shake flask culture utilising the same optimised media composition. This result demonstrated that the optimized media composition can be utilised for large-scale lipid production of UMACC-T023 for potential biodiesel feedstock as it also fulfilled the international standards for biodiesel.

Microstructural Characteristics And Mechanical Properties Of Sn-Ag-Cu Solders With Minor Additions Of Al And Zn, Yee Mei Leong

Student Works (2020-2029)

Driven by the recent trend towards miniaturization of lead free electronic products, researchers are putting immense efforts to improve the properties and reliability of Sn based solders. Recently, much interest has been shown on low silver (Ag) content solder SAC 105 (Sn-1.0Ag-0.5Cu) solder because of economic reasons and improvement of impact resistance as compared to SAC387(Sn-3.8Ag-0.7Ag). The present work investigates the effect of minor (0.1-0.5wt.%) Aluminium (Al) and Zinc (Zn) addition to SAC105 on the bulk and interfacial structure between solder and copper substrate during reflow and after thermal aging , the mechanical properties of the solder joint and the …