Physical Sciences and Mathematics Commons^™

The Reveal: A Technical Study And Conservation Treatment Of An Overpaint Portrait, Camille Ferrer

Art Conservation Master's Projects

A severely damaged 19th-century oil painting depicting a portrait of a woman was treated at Patricia H. and E. Garman Art Conservation Department. A typed letter provided by the owner mentioned that it has been previously restored yet returned with unsatisfactory results. After further examination, the painting appeared to have been previously treated multiple times by different people. There was overpaint distinctly present on the face and later discovered to be present overall. The full state of condition of the painting was initially unknown due to the sum of the surface being overpainted. However, there were evidence of paint loss …

Highly Toxic Aβ Begets More Aβ, Merc M. Kemeh, Noel Lazo

Chemistry

No abstract provided.

Tribocorrosion And Metal Release From Austenitic Stainless Steels 304 And 201 In Simulated Cassava Food Contact, Robert Addai, Temitope E. Olowoyo, Thalia E. Standish, Jeffrey Daniel Henderson, Ubong Eduok, Yolanda Hedberg

Chemistry Publications

Cassava is the third most significant calorie source in the tropics. Its processing has changed from traditional methods to stainless steel processing machines. This study investigated the influence of cassava on metal release from two common stainless steels, ASTM 304 and 201, with and without friction, and on tribocorrosion (multianalytically) of 304. Cassava was relatively corrosive and hindered repassivation of the surface oxide of stainless steel, but it also acted as a lubricant against mechanical friction. The combined action of friction and cassava caused a significant increase in iron, chromium, nickel, and manganese release from the stainless steels (30–35- fold …

Spectroscopic Characterization, Dft Calculations, In Vitro Pharmacological Potentials, And Molecular Docking Studies Of N, N, O-Schiff Base And Its Trivalent Metal Complexes, Ikechukwu P. Ejidike, Amani Direm, Cemal Parlak, Adebayo A. Adeniyi, Mohammad Azam, Athar Ata, Michael O. Eze, Joshua W. Hollett, Hadley S. Clayton

Michigan Tech Publications, Part 2

In this study, trivalent metal complexes of the category: [M(L)(H2O)nCly] obtained from the interaction of metal3+ ion salts with organic N, N, O-Schiff base (HL) (where: HL = 4-{(Z)-((2-{(E)-((2-hydroxyphenyl)methylidene)amino}ethyl)imino)methyl}-2-methoxyphenol; n, y = 1 or 2 and M = Ti(III), Fe(III), Ru(III), Cr(III) and Al(III)) were synthesized and characterized viz molar conductance, FT-IR, and UV–Vis spectroscopies, elemental analyses, thermal analyses (TGA and DTA), and UV–Vis spectroscopy, theoretical calculations. A distorted octahedral structure around the metal ions was proposed based on the obtained experimental and calculated data. Thermal examination of the complexes signposts the step-by-step disintegration to give the final decomposition product …

Hydrothermal Synthesis Of (C5h14n2)[Cocl4]⸳0.5h2o: Crystal Structure, Spectroscopic Characterization, Thermal Behavior, Magnetic Properties And Biological Evaluation, Sandra Walha, Noureddine Mhadhbi, Basem F. Ali, Abdellah Kaiba, Ahlem Guesmi, Wesam Abd El-Fattah, Naoufel Ben Hamadi, Mark M. Turnbull, Ferdinando Costantino, Houcine Naïli

Chemistry

The organic-inorganic compound (C₅H₁₄N₂)[CoCl₄]⸳0.5H₂O, I, was characterized by various physicochemical techniques. The X-ray diffraction analysis revealed that the compound crystallizes in the centrosymmetric space group C2/c of the monoclinic system. The atomic arrangement the Co(II) complex is built from isolated [CoCl₄]^2– anions, 1-methylpiperazine-1,4-diium [C₅H₁₄N₂]²⁺ cations and free water molecules. The crystal structure study showed that the cohesion of I is assured through N–H···Cl and N–H···O hydrogen bonds giving birth to a 3-D architecture. Hirshfeld surface analysis revealed that Cl···H/H···Cl and …

A Review Of The Toxicity Of Ingredients In E-Cigarettes, Including Those Ingredients Having The Fda's "Generally Recognized As Safe (Gras)" Regulatory Status For Use In Food., Nada O F Kassem, Robert M. Strongin, Andrea M. Stroup, Marielle C. Brinkman, Ahmad El-Hellani, Hanno C. Erythropel, Arash Etemadi, Vernat Exil, Maciej L. Goniewicz, Noura O. Kassem, Theodore P. Klupinski, Sandy Liles, Thivanka Muthumalage, Alexandra Noël, David H. Peyton, Qixin Wang, Multiple Additional Authors

Chemistry Faculty Publications and Presentations

Some firms and marketers of electronic cigarettes (e-cigarettes; a type of electronic nicotine delivery system (ENDS)) and refill liquids (e-liquids) have made claims about the safety of ingredients used in their products based on the term "GRAS or Generally Recognized As Safe" (GRAS). However, GRAS is a provision within the definition of a food additive under section 201(s) (21 U.S.C. 321(s)) of the U.S. Federal Food Drug and Cosmetic Act (FD&C Act). Food additives and GRAS substances are by the FD&C Act definition intended for use in food, thus safety is based on oral consumption; the term GRAS cannot serve …

Supplemental Information. Theoretical Rotational And Vibrational Spectral Data For The Hypermagnesium Oxide Species Mg2o And Mg2o+, Athena R. Flint, Brent R. Westbrook, Ryan C. Fortenberry

Faculty and Student Publications

Tables to accompany a forthcoming article in the journal ChemPhysChem.

Chm110 Principles Of Chemistry Lecture Slides, Leah S. Cohen

Open Educational Resources

These modified slides contain information from the first ten chapters from the General, Organic, and Biochemistry: connecting Chemistry to Your Life textbook by Blei & Odian.

Comparison Of Various Theoretical Measures Of Aromaticity Within Monosubstituted Benzene, Caleb K. Swain, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The effects of monosubstitution on the aromaticity of benzene are assessed using a number of different quantitative schemes. The ability of the mobile π-electrons to respond to an external magnetic field is evaluated using several variants of the NICS scheme which calculate the shielding of points along the axis perpendicular to the molecule. Another class of measures is related to the drive toward the uniformity of C-C bond lengths and strengths. Several energetic quantities are devised to approximate an aromatic stabilization energy and the tendency of the molecule to maintain planarity. There is a lack of consistency in that the …

Toxic Chocolate: An Investigation Of Heavy Metal Concentrations In Chocolate Products, Meredith E. Hoff

Student Scholarship

Many news organizations and scientific journals have recently reported high concentrations of lead and cadmium in chocolate products. The consumption of lead, cadmium, and other toxic metals can lead to numerous health impacts and impair development in children.1,2 Previous studies have specifically focused on the quantification of lead and cadmium in mainstream chocolate products, neglecting small businesses and the quantification of other heavy metals. This study addresses this disparity by analyzing the concentrations of lead, cadmium, barium, strontium, thallium, and mercury in lesser-known chocolate products from Castronovo Chocolate, Meridian Cacao Co., and Lidl. Two ICP-OES instruments and a direct mercury …

Purification And Isolation Of Α-Chloro-Β-Lactone Precursor Molecules, Matthew Ellis

Honors Projects

This research investigates the synthesis of α-chloro-β-lactone molecules, focusing on the production, isolation, and purification of two precursor compounds from chloroacetic acid and substituted benzaldehydes. While multiple methods were explored, including EDC, DIC, and DCC catalysis, DCC proved to be most effective in producing higher yields. However, challenges in purification arose due to the formation of byproducts, particularly with DCC, prompting further investigation for efficient extraction and purification techniques. DCC, however, shows a promising route for α-chloro-β-lactone synthesis, despite purification complexities.

Using Student Interests To Explore Inclusion In Undergraduate Chemistry, Sonja Hoversten

CSB and SJU Distinguished Thesis

For students who are not chemistry majors, but who are on a career track requiring four chemistry courses, taking the final reactivity chemistry course (CHEM 251) for pre-health students can be daunting. For this reason, this research is focused on the CHEM 251 course at The College of Saint Benedict and Saint John’s University (CSBSJU) which is one of the four required chemistry courses for pre-medicine and some pre-physician assistant students, and all chemistry and biochemistry majors. Student perception of inclusion in the course increased through the implementation of group assignments including prompts for individual application of the material. The …

Peace With Painful Memories, Mona Muzammil, Muzammil Arshad, Washain Muzammil

Chemistry Faculty Publications and Presentations

This Book helps you identify and heal from childhood emotional neglect so you can be more connected and emotionally present in your life.

Do you sometimes feel like you’re just going through the motions in life? Do you often act like you’re fine when you secretly feel lonely and disconnected? Perhaps you have a good life and yet somehow, it’s not enough to make you happy. Or perhaps you drink too much, eat too much, or risk too much to feel something good. If so, you are not alone and you may be suffering from emotional neglect.

Are you one …

Development Of An Enhanced Sampling Workflow To Accelerate Molecular Docking With Sparse Biophysical Information, Zachary Stichter

Masters Theses & Specialist Projects

Rapid docking of flexible biological macromolecules remains a significant open challenge in protein structure determination. While rigid docking is relatively simple with toolkits such as TagDock, a key obstacle to rapid flexible docking is the complexity and roughness of the free energy surface associated with protein conformational motion (often termed the many-minima problem), meaning conventional molecular dynamics methods do not effectively sample protein conformations near the interaction complex in accessible timescales. Methods such as metadynamics and replica exchange molecular dynamics exist to ameliorate this obstacle, yet these methods use nonphysical biases or random swaps to enhance sampling. In contrast, high …

Synthesis Of Thermoresponsive Poly(N-Isopropyl Acrylamide) Based Core-Shell And Hollow Shell Nanogel With Tunable Core And Shell Thickness, Mohamad Hijazi, Molla R. Islam

Student Scholar Symposium Abstracts and Posters

Nanogels have emerged as a notably safer and more effective means for drug delivery, primarily due to their adjustable drug-loading capabilities. Hollow-core nanoparticles offer some unique properties that are desirable for drug delivery applications. Initially, silica core nanoparticles were synthesized using the Stöber process at different temperatures where Tetraethoxysilane (TEOS) undergoes hydrolysis in the presence of ethanol and then a condensation reaction to form silica nanoparticles. Scanning Electron Microscopy (SEM) and Optical Microscopy (OM) analysis revealed that the size of silica core particles varied with the synthesis temperature (300 nm at 30°C to 150 at 60°C). The core silica particles …

Fluorescent Lifetimes Of Oils And Oil Distillates In Artificial Seawater, Warren J. De Bruyn, Aaron Harrison, Emma Kocik, Dhivya Manickam, Ethan Truong, Catherine D. Clark

Chemistry Faculty and Staff Publications

Supporting data associated with a study of the fluorescent lifetimes of eleven oil and oil distillates in artificial seawater are given. The table is a list of the oil and oil distillate names along with the associated sample numbers used in this study and their API densities.

The excel data file contains lifetimes as a function of emission wavelength for different oils and oil products shown by sample number. The lifetimes were measured with a Horiba DeltaFlex Lifetime System that uses pulsed diode light sources. There is a separate sheet for each excitation source: 268, 285 and 348 nm. Lifetimes …

Chm116 Principles Of Chemistry Ii Lecture Slides, Leah S. Cohen, Probal Banerjee

Open Educational Resources

This file contains the lecture slides that are used in CHM116, Principles of Chemistry II.

Optimization Of Xrf Experimental Protocol For Bruker Picofox, Tyler Ashcraft

Undergraduate Honors Theses

The research performed was to improve the precision and accuracy of sample measurements made with the Bruker Picofox X-ray fluorescence spectrometer. The initial method of sample preparation using a 10 μL drop spotted onto an acrylic plate and then drying in an oven at 80˚C produced inconsistent results even when processing replicates or the same sample multiples times. Multiple experiments were conducted to determine the effects of different sample preparation conditions on the resulting accuracy. The conditions tested were drop size, plate composition, and drying temperature. For each experiment an internal standard (gallium) was used at concentrations similar to that …

The Purification And Thermal Stability Of The Peroxidase Enzyme In Cucurbita Moschata, Garen Hamner

Senior Honors Theses

Peroxidases are enzymes that catalyze the reduction of hydrogen peroxide to water while oxidizing organic substrates and are valuable in spheres like industrial and medical applications and histochemistry. Limitations still exist in the use of the well-studied horseradish peroxidase for certain activities due to limitations like poor thermal stability, thus the search for novel peroxidases that can overcome these limitations is an active area of research. Butternut squash peroxidase (Cucurbita moschata) (BSP) shows promise due to significant activity being found in the skin and apparent enhanced thermal stability, but an efficient purification scheme for it is lacking, as well as …

Vt-Nmr Analysis Of Rotation-Inversion Of N-(4-Hydroxybutyl)-N-(2,2,2-Trifluoroethyl) Tert-Butyl Carbamate: Utilizing The −Ch2cf3 Appendage As A Reporter On E/Z-Isomerization, Brian Jameson, Rainer Glaser

Chemistry Faculty Research & Creative Works

The rotational barrier about the CN carbamate bond of N-(4-hydroxybutyl)-N-(2,2,2-trifluoroethyl) tert-butyl carbamate 1 was determined by variable temperature (VT) 13C and 19F NMR spectroscopy. The −CH2CF3 appendage reports on rotational isomerism and allows for the observation of separate signals for the E- and Z-ensembles at low temperature. The activation barrier for E/Z-isomerization was quantified using Eyring-Polanyi theory which requires the measurements of the maximum difference in Larmor frequency Δνmax and the convergence temperature Tc. Both Δνmax and Tc were interpolated by analyzing sigmoidal functions fitted to data describing signal separation and the quality of the superposition of the E- and …

Chemical And Physiological Interactions Between E-Liquid Constituents: Cause For Concern?, Robert M. Strongin, Eva Sharma, Hanno C. Erythropel, Nada O F Kassem, Alexandra Noël, D H. Peyton, Irfan Rahman

Chemistry Faculty Publications and Presentations

Studies of Electronic Nicotine Delivery Systems (ENDS) toxicity have largely focused on individual components such as flavour additives, base e-liquid ingredients (propylene glycol, glycerol), device characteristics (eg, model, components, wattage), use behaviour, etc. However, vaping involves inhalation of chemical mixtures and interactions between compounds can occur that can lead to different toxicities than toxicity of the individual components. Methods based on the additive toxicity of individual chemical components to estimate the health risks of complex mixtures can result in the overestimation or underestimation of exposure risks, since interactions between components are under-investigated. In the case of ENDS, the potential of …

Modern Approaches To Treating Hospital Acquired Infections: An Overview Of Current Treatments Using Antibiotics And New Therapies Centered Around Photo-Activated Porphyrins, Meghan Johns

Senior Honors Theses

Annually, hospital-acquired infections (HAIs) affect hundreds of thousands of people in the U.S. and impose a great economic burden. The current problem is further exacerbated due to the failure of traditional treatment strategies considering the rise in antimicrobial resistance rates. Besides the fact that antimicrobial resistances complicates clinical treatment strategies, patients are also more vulnerable to secondary infections and complications from prolonged antibiotic use. As a result, research investigating novel treatment strategies for bacterial infections has recently increased. A strategy using porphyrin-based compounds is showing promise. Porphyrins and their derivatives have exhibited bactericidal effects against Gram-positive bacteria by the destruction …

Scanning Electrochemical Microscopy Reveals That Model Silicon Anodes Demonstrate Global Solid Electrolyte Interphase Passivation Degradation During Calendar Aging, Josefine D. Mcbrayer, Noah B. Schorr, Mila Nhu Lam, Melissa L. Meyerson, Katharine L. Harrison, Shelley D. Minteer

Chemistry Faculty Research & Creative Works

Silicon is a promising next-generation anode to increase energy density over commercial graphite anodes, but calendar life remains problematic. In this work, scanning electrochemical microscopy was used to track the site-specific reactivity of a silicon thin film surface over time to determine if undesirable Faradaic reactions were occurring at the formed solid electrolyte interphase (SEI) during calendar aging in four case scenarios: formation between 1.5 V and 100 mV with subsequent rest starting at (1) 1.5 V and (2) 100 mV and formation between 0.75 V and 100 mV with subsequent rest starting at (3) 0.75 V and (4) 100 …

Apigenin Alleviates Autistic-Like Stereotyped Repetitive Behaviors And Mitigates Brain Oxidative Stress In Mice, Petrilla Jayaprakash, Dmytro Isaev, Keun-Hang Susan Yang, Rami Beiram, Murat Oz, Bassem Sadek

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Studying the involvement of nicotinic acetylcholine receptors (nAChRs), specifically α7-nAChRs, in neuropsychiatric brain disorders such as autism spectrum disorder (ASD) has gained a growing interest. The flavonoid apigenin (APG) has been confirmed in its pharmacological action as a positive allosteric modulator of α7-nAChRs. However, there is no research describing the pharmacological potential of APG in ASD. The aim of this study was to evaluate the effects of the subchronic systemic treatment of APG (10–30 mg/kg) on ASD-like repetitive and compulsive-like behaviors and oxidative stress status in the hippocampus and cerebellum in BTBR mice, utilizing the reference drug aripiprazole (ARP, 1 …

Structural, Spectroscopic, And Computational Insights From Canavanine-Bound And Two Catalytically Compromised Variants Of The Ethylene-Forming Enzyme, Shramana Chatterjee, Matthias Fellner, Joel A. Rankin, Midhun George Thomas, Simahudeen Bathir Jaber Sathik Rifayee, Christo Christov, Jian Hu, Robert P. Hausinger

Michigan Tech Publications, Part 2

The ethylene-forming enzyme (EFE) is an Fe(II), 2-oxoglutarate (2OG), and l-arginine (l-Arg)-dependent oxygenase that either forms ethylene and three CO2/bicarbonate from 2OG or couples the decarboxylation of 2OG to C5 hydroxylation of l-Arg. l-Arg binds with C5 toward the metal center, causing 2OG to change from monodentate to chelate metal interaction and OD1 to OD2 switch of D191 metal coordination. We applied anaerobic UV-visible spectroscopy, X-ray crystallography, and computational approaches to three EFE systems with high-resolution structures. The ineffective l-Arg analogue l-canavanine binds to the EFE with O5 pointing away from the metal center while promoting chelate formation by 2OG …

Advanced Electroanalysis For Electrosynthesis, Monica Brachi, Wassim El Housseini, Kevin Beaver, Rohit Jadhav, Ashwini Dantanarayana, Dylan G. Boucher, Shelley D. Minteer

Chemistry Faculty Research & Creative Works

Electrosynthesis is a Popular, Environmentally Friendly Substitute for Conventional Organic Methods. It Involves using Charge Transfer to Stimulate Chemical Reactions through the Application of a Potential or Current between Two Electrodes. in Addition to Electrode Materials and the Type of Reactor Employed, the Strategies for Controlling Potential and Current Have an Impact on the Yields, Product Distribution, and Reaction Mechanism. in This Review, Recent Advances Related to Electroanalysis Applied in Electrosynthesis Were Discussed. the First Part of This Study Acts as a Guide that Emphasizes the Foundations of Electrosynthesis. These Essentials Include Instrumentation, Electrode Selection, Cell Design, and Electrosynthesis Methodologies. …

Chiral Recognition Of Chiral (Hetero)Cyclic Derivatives Probed By Tetraaza Macrocyclic Chiral Solvating Agents Via ¹H Nmr Spectroscopy, Yu Wang, Hongmei Zhao, Chunxia Yang, Lixia Fang, Li Zheng, Hehua Lv, Pericles Stavropoulos, Lin Ai, Jiaxin Zhang

Chemistry Faculty Research & Creative Works

In the Field of Chiral Recognition, Chiral Cyclic Organic Compounds, Especially Heterocyclic Organic Compounds, Have Attracted Little Attention and Have Been Rarely Studied as Chiral Substrates by Means of 1H NMR Spectroscopy. in This Paper, Enantiomers of Thiohydantoin Derivatives, Representing Typical Five-Membered N,N-Heterocycles, Have Been Synthesized and Utilized for Assignment of Absolute Configuration and Analysis of Enantiomeric Excess. All Enantiomers Have Been Successfully Differentiated with the Assistance of Novel Tetraaza Macrocyclic Chiral Solvating Agents (TAMCSAs) by 1H NMR Spectroscopy. Surprisingly, Unprecedented Nonequivalent Chemical Shift Values (Up to 2.052 Ppm) of the NH Proton of Substrates Have Been Observed, a New …

Impact Of Pulsed Electric Field Treatment On Barley Germination For Malting, Rose Saxton, Caitlin Lahey, Brianna Smith, Emily Hibberd, Joshua Bevan, Cini Baumhoff, Ashley Galant, Jerry Young, Brian Meyer, Owen M. Mcdougal

Chemistry and Biochemistry Faculty Publications and Presentations

The malting process takes one week to steep, germinate, and kiln barley to make malt. Making quality malt is critically important to achieve the desired attributes of the finished beer, and the process is time-intensive and costly. Malt quality is assessed by indicators including β-glucan quantity, α-amylase activity, Free Amino Nitrogen (FAN) content, and overall extract concentration in the finished malt. Here, we report Pulsed Electric Field (PEF) treatment of barley to accelerate malt production. A small-scale trial of 250 g to 1.00 kg barley, was evaluated for germination at two PEF treatment conditions, generically referred to as “low” and …

Structure, Dynamics, And Redox Reactivity Of An All-Purpose Flavodoxin, Sharique Khan, Ahmadullah Ansari, Monica Brachi, Debarati Das, Wassim El Housseini, Shelley Minteer, Anne Frances Miller

Chemistry Faculty Research & Creative Works

The Flavodoxin Of Rhodopseudomonas Palustris CGA009 (Rp9Fld) Supplies Highly Reducing Equivalents To Crucial Enzymes Such As Hydrogenase, Especially When The Organism Is Iron-Restricted. By Acquiring Those Electrons From Photodriven Electron Flow Via The Bifurcating Electron Transfer Flavoprotein, Rp9Fld Provides Solar Power To Vital Metabolic Processes. To Understand Rp9Fld's Ability To Work With Diverse Partners, We Solved Its Crystal Structure. We Observed The Canonical Flavodoxin (Fld) Fold And Features Common To Other Long-Chain Flds But Not All The Surface Loops Thought To Recognize Partner Proteins. Moreover, Some Of The Loops Display Alternative Structures And Dynamics. To Advance Studies Of Protein–protein Associations …

Finding The Perfect Purple: An Exploration Of Glaze Making And Chemical Safety In The Pottery Studio, Kara Eppard, Michael Hough

ASPIRE 2024

This project was undertaken as an IDS-100H course linkage between ceramics and chemistry. Through time spent reviewing literature and time in the studio, a project was developed that allowed the application of technical skills of each discipline in a creative fashion. The creative focus of the project was to find a suitable purple glaze to utilize on a previously thrown pottery collection. During the project techniques in glaze making were explored. Over 25 glazes were tested, and two firing techniques were explored. Additionally, safety within the pottery studio was increased through aspects such as the development of an MSDS, and …