Chemistry Commons^™

Corn And Soybean Response To Wastewater-Recycled Phosphorus Fertilizers, Shane Ylagan

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

The ability to recycle phosphorus (P) from wastewaters could provide a sustainable, continuous source of P that might also help protect surface water quality from P enrichment. The mineral struvite (MgNH4PO4·6H2O) is an understudied material that can be created from Pcontaining wastewater and has been shown to have agricultural fertilizer value. The objective of this study was to evaluate the effects of electrochemically precipitated struvite (ECST), chemically precipitated struvite (Crystal Green; CG), diammonium phosphate (DAP), monoammonium phosphate (MAP), rock phosphate (RP), and triple super phosphate (TSP) on corn (Zea mays) and soybean (Glycine max) response in a 79-day greenhouse ...

Modification Of Chm20 Lab: Synthesis Of Aspirin, Nicole Diaz, Amy Musselman Prof.

KU Inspires! Undergraduate Research Day

No abstract provided.

Pilot-Scale Testing Of Uv-A Light Treatment For Mitigation Of Nh3, H2s, Ghgs, Vocs, Odor, And O3 Inside The Poultry Barn, Myeongseong Lee, Peiyang Li, Jacek A. Koziel, Heekwon Ahn, Jisoo Wi, Baitong Chen, Zhanbek Meiirkhanuly, Chumki Banik, William S. Jenks

Agricultural and Biosystems Engineering Publications

Poultry farmers are producing eggs, meat, and feathers with increased efficiency and lower carbon footprint. Technologies to address concerns about the indoor air quality inside barns and the gaseous emissions from farms to the atmosphere continue to be among industry priorities. We have been developing and scaling up a UV air treatment that has the potential to reduce odor and other gases on the farm scale. In our recent laboratory-scale study, the use of UV-A (a less toxic ultraviolet light, a.k.a. “black light”) and a special TiO2-based photocatalyst reduced concentrations of several important air pollutants (NH3, CO2, N2O ...

Tactviz: A Vmd Plugin For Tactile Visualization Of Protein Structures, Olivia R. Shaw, Jodi A. Hadden-Perilla

Journal of Science Education for Students with Disabilities

Scientific disciplines spanning biology, biochemistry, and biophysics involve the study of proteins and their functions. Visualization of protein structures represents a barrier to education and research in these disciplines for students who are blind or visually impaired. Here, we present a software plugin for readily producing variable-height tactile graphics of proteins using the free biomolecular visualization software Visual Molecular Dynamics (VMD) and protein structure data that is publicly available through the Protein Data Bank. Our method also supports interactive tactile visualization of proteins with VMD on electronic refreshable tactile display devices. Employing our method in an academic laboratory has enabled ...

Visualization Without Vision – How Blind And Visually Impaired Students And Researchers Engage With Molecular Structures, Croix J. Laconsay, Henry B. Wedler, Dean J. Tantillo

Journal of Science Education for Students with Disabilities

This article examines the tools and techniques currently available that enable blind and visually impaired (BVI) individuals to visualize three-dimensional objects used in learning chemistry concepts. How BVI individuals engage with and visualize molecular structure is discussed and recent tactile (or haptic) and auditory methods for visualization of various chemistry concepts are summarized. Remaining challenges for chemistry education researchers are described with the aim of highlighting the potential value of educational research in further enabling BVI students to pursue careers in science, technology, engineering, and mathematics (STEM) fields.

Structural Analysis Of Protein Therapeutics Using Covalent Labeling – Mass Spectrometry, Patanachai Limpikirati

Doctoral Dissertations

Using mass spectrometry (MS) to obtain information about a higher order structure of protein requires that a protein’s structural properties are encoded into the mass of that protein. Covalent labeling (CL) with reagents that can irreversibly modify solvent accessible amino acid side chains is an effective way to encode structural information into the mass of a protein, as this information can be read-out in a straightforward manner using standard MS-based proteomics techniques. The differential reactivity of proteins under two or more conditions can be used to distinguish protein topologies, conformations, and/or binding sites. CL-MS methods have been effectively ...

Solvent-Responsive Radical Dimers, Joshua P. Peterson, Arthur H. Winter

Chemistry Publications

An air- and thermally stable aryl dicyanomethyl radical is reported that switches between two dimeric forms—a σ dimer and a π dimer—by changing the solvent. The two dimer forms exhibit unique optical properties leading to solvatochromic behavior. The solvent-responsive behavior of these radicals can be explained by the higher polarizability of the pimer than the σ dimer that leads to pimer stabilization in polar solvents.

Collaborative Research: Mechanism And Target Recognition Of Protein Arginine Methyltransferases (Prmts), Joan Hevel

Funded Research Records

No abstract provided.

T1-Noise Eliminated Dipolar Heteronuclear Multiple-Quantum Coherence Solid-State Nmr Spectroscopy, Amrit Venkatesh, Xuechen Luan, Frederic A. Perras, Ivan Hung, Wenyu Huang, Aaron Rossini

Chemistry Publications

Heteronuclear correlation (HETCOR) spectroscopy is one of the key tools in the arsenal of the solid-state NMR spectroscopist to probe spatial proximity between two different nuclei and enhance spectral resolution. Dipolar heteronuclear multiple-quantum coherence (D-HMQC) is a powerful technique that can be potentially utilized to obtain ¹H detected 2D HETCOR solid-state NMR spectra of any NMR active nucleus. A long-standing problem in ¹H detected D-HMQC solid-state NMR experiments is the presence of t₁-noise which reduces sensitivity and impedes spectral interpretation. In this contribution, we describe novel pulse sequences, termed t₁-noise eliminated (TONE) D-HMQC, that ...

Synthesis And Fabrication Of Self-Sustainable Triboelectric, Abu Masa Abdullah, Alejandro Flores, Aminur Rashid Chowdhury, Jianzhi Li, Yuanbing Mao, Jasim Uddin

Chemistry Faculty Publications and Presentations

In recent times, Triboelectric Nanogenerators (TENG) have attained the focus of the scientific community due to its potential as a medium to harvest mechanical energy from the ambient environment. Human motion has been attributed as a source of mechanical energy to drive electronic devices and sensors through TENG. Based on the principles of single electrode TENG, we have developed a Triboelectricity based Stepping and Tapping Energy Case (TESTEC) which magnifies the prospect to power touch electronic devices by utilizing finger tapping and stepping motion. This novel case was constructed with two single electrode TENG operating through the triboelectric mechanism between ...

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 ...

Glyoxal’S Impact On Dry Ammonium Salts: Fast And Reversible Surface Aerosol Browning (Raw Data), David O. De Haan Phd, Lelia N. Hawkins Phd, Margaret A. Tolbert Phd, 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 estimated Ångstrom absorbance coefficient of -16 ±4. This coefficient and the empirical relationship between GX and albedo are used to estimate an upper limit to global radiative forcing by brown carbon formed by 70 ppt GX reacting with AS (+7.6 ´10-5 W/m2). This quantity is < 1% of the total radiative forcing by secondary brown carbon, but occurs almost entirely in the ultraviolet range.

The zipped data files are in the following formats: Igor experiments (.pxp), Word documents (.docx), Excel spreadsheets (.xlsx), organized by experiment number. “Optical” files contain cavity attenuated phase shift (CAPS) extinction, scattering and albedo data; PILS/waveguide data (experiments 1,2, and ...

Synthesis Of Alpha-Methylselenocysteine, Its Relevant Analogues, And An Unnatural Glutathione Disulfide Core, Robert J. Wehrle

Dissertations

Selenoproteins, such as glutathione peroxidase, have gained interest for their ability to act as antioxidants, and their potential to act as anti-cancer agents. Synthesizing and studying selenoproteins can be problematic, however, due to their propensity to degrade from over-oxidation. The degradation from over-oxidation can be avoided by the incorporation of the unnatural amino acid, alpha-methylselenocysteine. A synthesis utilizing methyl malonic esters was used to synthesize protected (R)-alpha-methylselenocysteine efficiently (46% over four steps) and in high enantio-purity (88% enantiomeric excess). Using similar procedures, the (S)-enantiomer was also synthesized as well as a beta-analogue.

The use of enzymes in a ...

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 treatment, the ...

Search For Encapsulation Of Platinum, Silver, And Gold At The Surface Of Graphite, Ann Lii-Rosales, Yong Han, Dapeng Jing, Michael C. Tringides, Patricia A. Thiel

Chemistry Publications

Using scanning tunneling microscopy, we show that Pt clusters can be encapsulated beneath the surface of graphite, whereas Ag and Au cannot. This is in complete agreement with independent predictions from density functional theory, which show that surface intercalation of single metal atoms is favorable for Pt, but unfavorable for Ag and Au. This supports the validity of using single-metal-atom energetics for predicting encapsulation of metal nanoparticles at the graphite surface. We also demonstrate that the optimal temperature for encapsulation scales with the cohesive energy of the metal.

California - Cottonwood Weigh Station

On-road Heavy-duty Monitoring System

No abstract provided.

California - Port Of Los Angeles

On-road Heavy-duty Monitoring System

No abstract provided.

Surface Chemistry Of Ternary Nanocrystals: Engineering The Deposition Of Conductive Nabis2 Films, Alan M. Medina-Gonzalez, Bryan A. Rosales, Umar H. Hamdeh, Matthew G. Panthani, Javier Vela

Chemistry Publications

The ability to engineer the surface chemistry of complex ternary nanocrystals is critical to their successful application in photovoltaic, thermoelectric, and other energy conversion devices. For many years, several studies have shed light into the surface chemistry of unary and binary semiconductor nanocrystals, as well as their surface modification with monodentate and multidentate ligands in a variety of applications. In contrast, our understanding of the surface chemistry and ligand modification of ternary and other complex multinary nanocrystals remains relatively limited. Recently, our group reported the synthesis of colloidal NaBiS2 semiconductor nanocrystals with sizes tunable between 2–60 nm, and a ...

Enhanced Intersystem Crossing And Transient Electron Spin Polarization In A Photoexcited Pentacene-Trityl Radical, Claudia E. Avalos, Sabine Richert, Etienne Socie, Ganesan Karthikeyan, Gilles Casano, Gabriele Stevanato, Dominik J. Kubicki, Jacques E. Moser, Christiane R. Timmel, Moreno Lelli, Aaron J. Rossini, Olivier Ouari, Lyndon Emsley

Chemistry Publications

Identifying and characterizing systems that generate well-defined states with large electron spin polarization is of high interest for applications in molecular spintronics, high-energy physics and magnetic resonance spectroscopy. The generation of electron spin polarization on free-radical substituents tethered to pentacene derivatives has recently gained a great deal of interest for its applications in molecular electronics. After photoexcitation of the chromophore, pentacene-radical derivatives can rapidly form spin-polarized triplet excited states through enhanced intersystem crossing. Under the right conditions, the triplet spin polarization, arising from mS-selective intersystem crossing rates, can be transferred to the tethered stable radical. The efficiency of this spin ...

Plasmon-Enabled Physical And Chemical Transformations Of Nanomaterials, Danielle Mcrae

Electronic Thesis and Dissertation Repository

When the electromagnetic field of light is incident on metallic nanostructures of dimensions smaller than the incident wavelength of the light, there is a strong interaction, resulting in an enhanced, highly confined electromagnetic field in the vicinity of the nanostructure. This effect is referred to as a localized surface plasmon resonance, most commonly exploited for plasmon-enhanced spectroscopies, such as surface-enhanced Raman spectroscopy (SERS) and tip-enhanced Raman spectroscopy (TERS). The location, number and intensity of these regions of enhancement, or “hotspots”, can be tuned by changing the nature of the metal, the size, shape and arrangement of the nanoparticles, its surroundings ...