Chemistry Commons^™

Understanding Favorability In Diels-Alder Reaction For Hydrogel Synthesis: A Computational Study, Sejal Bhasin

Honors Theses

This study delves into analyzing the change in reaction enthalpy and activation energies of the Diels-Alder reaction for the synthesis of hydrogels, possessing diverse applications in scientific domains due to their unique properties. Utilizing the Diels-Alder reaction for hydrogel creation allows tailored structures responsive to specific stimuli. Theoretical calculations, employing computational methods, utilized the latest Spartan software (version 20) and conducting gas-phase calculations with semi-empirical methods (PM3) and Hartree-Fock (6-31G*). This research examines the hypothesis regarding the potential enhancement of reaction favorability through the introduction of an aromatic ring into the product, along with the incorporation of an electron-donating group …

Determination Of The Presence Of Gun Powder Residue On Civil War Era Pulaski Musket With Xrf, Katelynn Mostek, Joshua Sebree

Fall 2023 - Chemical Analysis Class Projects

The goal of this project is to determine if the Civil War era Pulaski Musket owned by the UNI museum has been fired before. To do this, the presence of gun powder residue on the Pulaski Musket was compared to other gun from the museum's collection via X Ray Fluorescence. Sulfur and lead components that typically make up gun powder residue were analyzed.

Determination Of Oils In African Mende Helmet Mask Raffia Fiber Using Gas Chromatography, Megan M. Unger, Joshua Sebree

Fall 2023 - Chemical Analysis Class Projects

• African Mende helmet mask that is traditionally work during coming-of-age ceremonies.
• It is made from wood and finished in a black color made from vegetable dye.
• The raffia fibers come from a plant known as ‘raffia bamboo’.
• The African Mende helmet mask given to the UNI Museum was originally used in a classroom and is believed that it was not well preserved.
• The teacher reportedly used vegetable oil on the wooden part of the mask to keep the original look.
• unknown whether there have been more oils used on the mask.

Analyzing Microstructural Variations In Ancient Bricks: A Comparative Study Using Sem Analysis, Sabryn Labenz, Joshua Sebree

Fall 2023 - Chemical Analysis Class Projects

• A brick was donated to the University of Northern Iowa that was believed to have originated from Mesopotamia. However, the museum suggests the possibility it originated from Egypt.
• Brick structure can vary based on the raw materials used in their construction
• The size of the sand particles used in bricks contribute to the brick’s structural integrity.
• Bricks from Iran and England were analyzed for regional similarities to the unknown brick using Scanning Electron Microscopy (SEM).

Uv-Vis Spectral Analysis Of Mende Cultural Mask, Kameron Kruger, Joshua Sebree

Fall 2023 - Chemical Analysis Class Projects

• The UNI Museum possesses a mask that originated from the Mende people of Sierra Leone, and has since been used as an educational tool. While the rafia fibers at the base have been replaced, the wooden mask is original.
• Under black light, the mask shows a complex fluorescence pattern that includes distinct regions of green, orange, and dark purple.
• This work used UV Vis spectroscopy to analyze the mask and potentially identify functional groups associated with compounds on the surface, such as oils and other wood preservatives. As many historical wood preservatives are known to damage their artifacts over time, …

X-Ray Analysis Of An Ancient Brick To Determine Its Origin, Jenna E. Heinen, Joshua Sebree

Fall 2023 - Chemical Analysis Class Projects

• This research is focused on studying an ancient brick of unknown origin which is housed in the University of Northern Iowa Museum
• It is theorized to be from Egypt during the time of the Israelite’s enslavement
• There are many disputes about the above claim; others believe it could be from Mesopotamia long after the time of Israelites lived in Egypt
• A museum artifact, determining the history and origin of this brick to a better understanding of its meaning and significance for historians and museum goers alike.

Examining The Metals Present In A Confederate Contact Musket Using Xrf, Lydia E. Richardson, Joshua Sebree, Colin Weeks

Fall 2023 - Chemical Analysis Class Projects

• Pulaski musket was made during Civil War in Pulaski, Tennessee
• Believed the Pulaski is compiled together using old rifles and muskets

Modulation Of Electrocatalytic Activity By Tuning Anion Electronegativity: Case Study With Copper Chalcogenides, Harish Singh, David Prendergast, Manashi Nath

Chemistry Faculty Research & Creative Works

Anion-tuning in metallic chalcogenides has been shown to have a significant impact on their electrocatalytic ability for overall water splitting. In this article, copper-based chalcogenides (Cu2 X, X= O, S, Se, and Te) have been systematically studied to examine the effect of decreasing anion electronegativity and increasing covalency on the electrocatalytic performance. Among the copper chalcogenides, Cu2Te has the highest oxygen evolution reaction (OER) activity and can sustain high current density of 10 and 50 mA cm−2 for 12 h. The difference in intrinsic catalytic activity of these chalcogenide surfaces have been also probed through density functional theory calculations, which …

Computational Investigation Of Mononuclear Iron Water Oxidation Catalyst Design, Kristal Stevens, Emily Jarvis

Chemistry and Biochemistry Faculty Works

Hydrogen production from non-carbon sources is an essential component of clean and sustainable technology for reducing greenhouse gas emissions from fuels. Water oxidation, which splits water molecules into hydrogen (protons) and molecular oxygen, is a thermodynamically challenging, multistep reaction achieved in photosynthetic organisms via photocatalysis by the Oxygen Evolving Complex (OEC) of Photosystem II. Mononuclear water oxidation catalysts that aim to mimic nature typically rely on heavy, rare metals such as ruthenium and iridium. Replacing these metals with iron is particularly appealing because it is abundant, benign, and inexpensive. We use density functional theory to characterize the catalytic ability of …

Reactive Molecular Dynamics Of Large Systems: Quantum Dynamics With Adaptable Gaussian Bases; Hydroxide Diffusion In A Polymeric Environment, Mohottige Sachith Prasanga Wickramasinghe

Theses and Dissertations

This dissertation describes our research in theory and applications of reactive molecular dynamics. Quantum dynamics provides the foundation for understanding chemical processes. However, the computational cost of describing a general quantum system scales exponentially with the system size. Thus, an efficient basis representation of wavefunctions is essential. Time-dependent Gaussian bases are often employed to describe the large-amplitude motion of high-dimensional systems. The time dependence of such bases is typically determined by (i) the variational principle or by (ii) classical dynamics. But those approaches have shortcomings due to intrinsic singularity of the variational equations in the full basis limit or due …

A Work Towards A Single-Bridge Hydrazine Sensor, Brenden Jay Schmeltz

Theses and Dissertations

Hydrazine can currently be detected by irreversible methods, Carbazolopyridinophane (2,18-Dithia[3][1,8]carbazolo[3][2,6]pyridinophane) CP was synthesized by Brown et al. to detect hydrazine in real-time while also being reversible. The threshold for detection was 100 ppb, regulatory use requires 10 ppb as this is when permanent damage to humans can be caused. A more sensitive sensor will allow for safer workplaces for many people. A single, 3-atom bridge sensor will further examine the photophysical capabilities of carbazole-pyridine as an emitter/quencher pair. 1-Carbazole-1-methylpyridyl-2methyl sulfide SBCP will allow freedom of rotation as well as the bending of the bridge. These benefits will introduce conformers which …

Investigating Evidence In Support Of Validity And Reliability For Data Collected With The Meaningful Learning In The Laboratory Instrument (Mlli), Elizabeth Vaughan, A. Montoya-Cowan, Jack Barbera

Chemistry Faculty Publications and Presentations

The Meaningful Learning in the Laboratory Instrument (MLLI) was designed to measure students’ expectations before and after their laboratory courses and experiences. Although the MLLI has been used in various studies and laboratory environments to investigate students’ cognitive and affective laboratory expectations, the authors of the instrument reported a discrepancy between the intended factor structure of the MLLI and the factor structure suggested by the data collected in preliminary studies. Therefore, the aim of this study was to investigate the validity and reliability evidence related to data collected with the MLLI, especially that related to structural validity. Evidence to support …

Interfacial Ligand Transformation On Plasmonic Nanostructures: Mechanistic Insights Unraveled By Plasmon-Enhanced Spectroscopy, Kexun Chen

Theses and Dissertations

We employ surface-enhanced Raman scattering (SERS) as an in situ spectroscopic tool, in conjunction with density functional theory (DFT) calculations, to develop a detailed mechanistic understanding of plasmon-driven photocatalytic reactions and heterogeneous transfer hydrogenolysis reactions of molecular adsorbates on metallic nanostructure surfaces. The excitation and decay of plasmon resonances in metallic nanostructures give rise to intriguing photophysical and photochemical effects, including the generation of hot charge carriers, local field enhancements, and photothermal transduction. These effects can be intentionally harnessed to drive or enhance interfacial molecular transformations along unconventional reaction pathways. The first part of the thesis focuses on the plasmon-driven …

Investigation, Synthesis And Rational Design Of Novel Transuranic Containing Extended Structures, Adrian Thomas Hines

Theses and Dissertations

The use of nuclear technology has proven useful for energy generation and for weapons manufacturing, but disposal and storage of nuclear waste is an ongoing problem. The accumulation of nuclear waste over the past decades has yielded a vast amount of waste that must be dealt with, and with space at interim storage facilities diminishing, it has become increasingly important to find solutions to nuclear waste storage. The vitrification process has been widely accepted as a viable route for immobilization of high-level waste; however, the process is inadequate for complex waste streams and has many drawbacks such as limited waste …

Antimicrobial Polymers And Small Molecules From Multicyclic Compounds And Engineering Of Sustainable Polymers, Leman Buzoglu Kurnaz

Theses and Dissertations

In this dissertation, the synthesis of polymers and small molecules from multicyclic compounds and the development of sustainable polymers from renewable feedstock were investigated. The antimicrobial biomaterials and sustainable polymers were characterized and their properties were discussed. In Chapter 1, the overall background and recent developments of antimicrobial biomaterials and their application were discussed. Later, sustainable polymers from renewable biomass and their synthesis methods were given. Afterward, the main research objectives of this doctoral research study were described. In Chapter 2, the synthesis of multiple charged small molecules from multicyclic compounds was discussed. These compounds were obtained by using various …

Exploring The Assembly Of Soluble Triphenylamine Bis-Urea Macrocycles; Synthesis Of Nsc243928 Derivatives For Triple-Negative Breast Cancer Treatment, Rahul Prakash

Theses and Dissertations

This dissertation is divided into two topics: I. Supramolecular polymerization of triphenylamine (TPA) bis-urea macrocycle behavior in solution, and II. Synthesis of fluorophore appended and biotinylated derivatives of NSC243928 for the treatment of triple-negative breast cancer. Supramolecular polymers are of interest due to their self-healing and stimuli responsiveness. Chapter 1 gives a brief overview of the importance of self-assembly to construct ordered structures from smaller building blocks, highlighting the mechanisms of self-assembly to form supramolecular polymers. The bis-urea macrocycle assembly unit is introduced and its assembly into tubular structures and crystals is highlighted, which are used as a control for …

Structural, Functional And Biochemical Studies To Elucidate The Molecular Basis Of Xenobiotic Metabolism Of Tetranychus Uritcae, A Major Agricultural Pest, Ricardo Hernandez Arriaza

Theses and Dissertations

The two-spotted spider mite, Tetranychus urticae, is a major cosmopolitan pest that feeds on more than 1,100 plant species, including 150 crops. Such a wide host range indicates this mite’s unparalleled xenobiotic responsiveness that is also coincident with their ability to rapidly develop resistance to pesticides. An unprecedently large detoxifying machinery is one of the main biological traits responsible for their extraordinary adaptation potential and devastating effect on crops. Availability of the whole genome sequence revealed expansions in all major detoxifying families and demonstrated that this genome has been enriched by horizontally transferred genes from bacteria and fungi. Motivated by …

Design And Synthesis Of N-Succinyl-L,L-2.6-Diaminopimelic Acid Desuccinylase Inhibitors As Potential Novel Antibiotics, Thomas Dipuma

Master's Theses

N-Succinyl-L,L-2,6-Diaminopimelic Acid Desuccinylase (DapE) is a bacterial enzyme located in the lysine biosynthetic pathway of all Gram-negative and most Gram-positive species of bacteria including the notorious ESKAPE pathogens, or pathogenic strains of bacteria that have developed significant levels of resistance to currently available antibiotics. As a means to combat this challenge of growing antimicrobial resistance, we have identified the bacterial enzyme DapE as a conserved, novel enzymate target within these resistant bacterial strains,as DapE is responsible for the production of m-DAP and lysine which are ultimately employed in bacterial cell wall synthesis. The overall aim of this research is to …

Improved Temperature Dependence Of Rate Coefficients For Rotational State-To-State Transitions In H2O + H2O Collisions, Bikramaditya Mandal, Dmitri Babikov

Chemistry Faculty Research and Publications

Aims. We present an improved database of temperature-dependent rate coefficients for rotational state-to-state transitions in H₂O + H₂O collisions. The database includes 231 transitions between the lower para-states of H₂O and 210 transitions between its lower ortho-states (up to j = 7) and can be employed in cometary and planetary applications up to the temperature of 1000 K.

Methods. We developed and applied a new general method that allows the generation of rate coefficients for excitation and quenching processes that automatically satisfy the principle of microscopic reversibility and also helps to cover …

Enhanced Cell Viability And Migration Of Primary Bovine Annular Fibrosus Fibroblast-Like Cells Induced By Microsecond Pulsed Electric Field Exposure, Prince M. Atsu, Connor Mowen, Gary L. Thompson Iii

Henry M. Rowan College of Engineering Departmental Research

This study is the first to report the enhancement of cell migration and proliferation induced by in vitro microsecond pulsed electric field (μsPEF) exposure of primary bovine annulus fibrosus (AF) fibroblast-like cells. AF primary cells isolated from fresh bovine intervertebral disks (IVDs) are exposed to 10 and 100 μsPEFs with different numbers of pulses and applied electric field strengths. The results indicate that 10 μs-duration pulses induce reversible electroporation, while 100 μs pulses induce irreversible electroporation of the cells. Additionally, μsPEF exposure increased AF cell proliferation up to 150% while increasing the average migration speed by 0.08 μm/min over 24 …

Optical Characterization Of Photocatalytic Tungsten Oxide/Tin Oxide (〖Wo〗_3/〖Sno〗_2) Thin Films For Use In Degradation Of Water Pollutants, Victor Isahi, Christopher Maghanga, Mghendi Mwamburi, Onesmus Munyati, Sylvester Hatwaambo, Emmanuel Akoto, Wycliffe Isoe, Mir Waqas Alam

Tanzania Journal of Science

Organic pollutants in water have been a challenge and pose significant risks to human health. As a result, research efforts to eliminate these pollutants have been on the rise. Photocatalysis has shown incredible potential in water treatment containing organic pollutants since it is affordable and utilizes solar energy. Tin oxide ( ) has ardently been investigated as a photocatalyst for water treatment due to its remarkable properties such as; non-toxicity, and stability. However, its wide band gap and the tendency for some electrons and holes to recombine during its use have been cited to be among limiting factors affecting its …

Hydro-Geochemistry And Related Processes Controlling The Composition Of Thermal Waters In The Lake Natron Basin, Northern Tanzania, Edista A. Abdallah, Charles H. Kasanzu, Crispin P. Kinabo, Akira Imai

Tanzania Journal of Science

Lake Natron Basin (LNB) forms part of the eastern branch of the East African Rift System (EARS) in Tanzania. The basin is endowed with thermal springs flowing towards the lake from the western, northwestern, southwestern and eastern parts. The western, northwestern and south-western thermal springs emanate from fractures in the basaltic rocks while in the east, they originate from the western flank of the Gelai volcano. There are limited studies on these springs, thus their geochemical differences and distributions of physicochemical parameters are not well understood. A hydrogeochemical study was conducted to interpret available geochemical data from the LNB springs, …

Evaluation Of The Inhibitive Properties Of Silver Nanoparticles In Senna Occidentalis Root Extract As Corrosion Inhibitor Of Mild Steel, Victor O. Egbeneje, Samuel E. Okhale, Chinyere Imoisi, Isaac O. Ogbogo, Omolade Ojo

Tanzania Journal of Science

The use of nanoparticles as corrosion inhibitors has gained popularity because of its increased corrosion efficiency due to increase surface to volume ratio. Nanoparticles which undergo physisorption/chemisorption to the corrosion metal surface and inhibit the corrosion efficiently also have low toxicity, low cost and easy production. In this research work, weight lost method was applied to study the inhibitive properties of silver nanoparticles (AgNPs) synthesized using Senna occidentalis root extract as environmentally benign corrosion inhibitor of mild steel in 0.5 M H2SO4 medium at 298 K and 308 K. It was observed that the corrosion rate of the steel sample …

Exploring The Correlation Between Metacognitive Skills And Cognitive Learning Outcomes Across Various Biology Learning Models In High Schools, Ninik Kristiani, Herawati Susilo, Aloysius Duran Corebim, Fatchur Rohman

Jurnal Pendidikan Sains

In Malang City, a notable observation within the realm of high school biology education suggests a prevalent lack of metacognitive knowledge among teachers, hindering their efficacy in nurturing students' metacognitive capacities. Such deficiency yields implications for diminished cognitive abilities among students. Recognizing this, there emerges a pressing need for an enhanced pedagogical framework capable of fostering metacognitive skills adeptly. One promising approach involves integrating inquiry-based learning and problem- based mindful pedagogy (PBMP). This amalgamation is anticipated to synergistically harness the potential of both methodologies in bolstering metacognitive skills alongside cognitive learning outcomes. This study adopts a correlational research design, wherein …

Analysis And Unraveling Misconceptions: Examining Tenth-Grade High School Students’ Errors In Hots Questions On Exponential Equations And Effective Scaffolding Strategies, Nunik Indayani, Erry Hidayanto, Sisworo Sisworo

Jurnal Pendidikan Sains

The objective of this study is to elucidate the errors made by tenth-grade students at SMA Hati Bilingual Boarding School Probolinggo, Indonesia, when tackling Higher Order Thinking Skills (HOTS) questions on exponential equations, along with the scaffolding process employed to mitigate these errors. Employing qualitative research methods, four participants were chosen based on their performance in completing HOTS questions on exponential equations, followed by in-depth interviews. The identified student errors encompass basic errors, appropriate errors, missing information, and partial insights. The analysis aligns these errors predominantly with Brodie’s error taxonomy. Furthermore, the study highlights the efficacy of instructional scaffolding, utilizing …

The Identification Of Students’ Conceptual Mastery Of Fluid Statics: An Overview Of Gender, Maria Claudia Sodakain, Sentot Kusairi, Nandang Mufti, Jane Koswojo

Jurnal Pendidikan Sains

This study aimed to assess the conceptual mastery of fluid statics among students, employing a descriptive quantitative approach. The research involved 22 male and 13 female students from eleventh-grade MIPA at a private school in Surabaya, Indonesia. The primary research instrument comprised 11 multiple-choice and reasoning questions, covering concepts related to Pressure and Hydrostatic Pressure, Pascal’s Law, and Archimedes’ Principle. Results indicated a higher level of conceptual mastery among male students compared to their female counterparts. While both genders demonstrated relatively high conceptual mastery in Pressure and Hydrostatic Pressure, significant disparities were observed in their understanding of Pascal’s Law and …

Analysis Of Student Engagement And Perceptions Of Community Of Inquiry (Coi)-Based Blended Learning In The Chemical Separation Subject On Chromatography, Agita Dzulhajh Anggraini, Surjani Wonorahardjo, Yudhi Utomo

Jurnal Pendidikan Sains

Learning in higher education has often been conducted solely through face-to-face, teacher- centered approaches. Implementing Community of Inquiry (CoI)-based blended learning in chromatography is crucial as it offers students a novel learning experience. This pre- experimental study, utilizing a one-group pretest-posttest design, aimed to describe students’ perceptions of CoI-based blended learning in chromatography. Data were collected using a questionnaire comprising 34 statements. The results indicated that students had a neutral perception of CoI-based blended learning. While a community of inquiry has been established, it has not yet reached its full potential, as students have not fully experienced social presence in …

Mineralogy And Geochemical Characteristics Of Matamba Kaolin Deposit-Njombe Region South-Western Tanzania: Implications For Industrial Applications, Melania A. Nyimbo, Ronald J. Massawe, Michael M. Msabi

Tanzania Journal of Science

Kaolin is a commercial clay material composed of hydrated aluminosilicate mineral kaolinite and used in various industrial applications such as ceramics, paper, paints, refractories, fiberglass, plastics, cosmetics and pharmaceuticals. It is formed as a result of strong chemical weathering of crystalline and feldspar-rich rocks or hydrothermal alteration of granitic rocks at relatively low temperature and pressure conditions. The kaolin deposit of Matamba originated from the weathering of leucogabbro rock during the development of the African land surface. In view of highlighted properties, the mineralogy and chemical characteristics of the Matamba kaolin deposit were investigated to determine its industrial applications. As …

Microplastics In Marine Sediments From Dar Es Salaam Coast: Spatial Distribution And Characterization, Macarius P. Mtega, Matobola J. Mihale, Kessy F. Kilulya

Tanzania Journal of Science

The purpose of the research was to determine the spatial distribution and characterization of microplastics in marine sediments of beaches along the Indian Ocean of Dar es Salaam coast. The sediment samples were extracted in triplicate using floatation method followed by digestion of organic debris, then analyzed using At-FTIR spectrophotometer and stereomicroscope. The mean concentrations of microplastics for Kijichi Beach were 700 ± 907 particles/m2 at 1 cm, 859 ± 839 particles/m2 at 5 cm and 590 ± 782 particles/m2 at 10 cm; from Palm Beach were 157 ± 15 particles/m2 at 1 cm, 130 ± 182 particles/m2 at 5 …

Molecularly Imprinted Electrochemical Sensor Based On Poly (O-Phenylenediamine) For Sensitive Detection Of Oxycodone In Water, Pranaya Charkravarthula, Amos Mugweru

College of Science & Mathematics Departmental Research

This work was aimed at the development of a sensitive electrochemical detection method for oxycodone in water. Molecularly imprinted electrodes were formed by electro-polymerization process using o-phenylenediamine as a monomer. The electro-polymerization was performed on glassy carbon electrodes in the presence of oxycodone before the extraction of entrapped oxycodone molecules. Various electrochemical techniques were employed to monitor the polymerization and response of the fabricated electrodes toward oxycodone. These techniques included cyclic voltammetry (CV), square wave voltammetry (SWV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). The oxycodone concentration was determined using SWV by measuring the change in the oxidation …