Physical Sciences and Mathematics Commons^™

Quantifying Time-Dependent Structural And Mechanical Properties Of Uv-Aged Ldpe Power Cables Insulations, Abdallah Hedir, Ferhat Slimani, Mustapha Moudoud, Omar Lamrous, Tahar Touam, Madjid Teguar, Abderrahmane Haddad, Ali̇ Durmuş

Turkish Journal of Chemistry

This paper reports effects of ultraviolet (UV) light radiation on the physicochemical, electrical and mechanical properties of low-density polyethylene (LDPE) cable insulating materials. Changes in structural and morphological properties of UV-aged samples were characterized by various analytical methods such as attenuated total reflection Fourier transform infrared spectroscopy (ATRFTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Additionally, elongation at break, tensile strength, dielectric strength, and optical properties were also evaluated. Changes in some physical properties of LDPE after exposing to UV irradiation clearly highlighted that the polymer underwent the structural degradation. In addition, it was also …

Synthesis And Investigation Of A Hexyl Substituted Thieno-Fused Bodipy Derivative As A Versatile Near-Ir Fluorophore, Yusuf Çakmak

Turkish Journal of Chemistry

The synthesis, photophysical and electrochemical properties of hexyl thiophene substituted thieno[b]-fused BODIPY structure are reported within this work. One such derivative, HTFBod, has been studied, which is one of the rare compounds that has a maximum absorbance wavelength greater than 750 nm among fused BODIPY compounds. In addition, it preserves its significant spectral properties such as high molar absorptivity and fluorescence quantum yield. Electrochemical characterizations indicated that the compound could be a successful candidate for an organic solar cell donor compound due to its low band gap, which is known to improve the short-circuit current (Jsc) values. The compound could …

Mil-53(Al) Catalytic Synthesis Of Poly(Ethylene Terephthalate), Ji Wang, Qingyin Wang, Gongying Wang

Turkish Journal of Chemistry

Poly(ethylene terephthalate) (PET) is one of the world's five major engineering plastics and is widely used in various fields. At present, the main catalysts used in the synthesis of PET are antimony, titanium, and aluminum metal compounds. Among them, antimony-based catalysts are poisonous and the titanium-based catalyst products are relatively yellow in hue. The aluminum-based catalyst has the advantages of low price and environmental friendliness, but current research shows that the organoaluminum catalyst has the problem of hydrolysis, and MIL-53 (Al) has good stability and will not affect the environment, so we add a catalyst before the esterification reaction, and …

A Facile Synthesis Of Ag2Mnsns4 Nanorods Through Colloidal Method, Sultan Süleyman Özel, Serdar Akay, Faruk Özel

Turkish Journal of Chemistry

The production methods of semiconductor nanomaterials with new shapes and different compositions form the basis for the creation of high-performance structures in numerous applications. Kesterite structured materials are among these inorganic semiconductors and are suggested to be promising energy materials for the future. In this study, quaternary Ag₂MnSnS₄ nanocrystalline rods have been successfully synthesized for the first time by the colloidal hot-injection synthesis route and well-organized rod-like nanocrystals (NCs) with lengths ranging from 200 to 350 nm and widths from 10 to 30 nm were obtained. For this structure, the Ag₂MnSnS₄ exhibits a semiconductor …

Catalytic Pyrolysis Of Olive Oil Residue To Produce Synthesis Gas: The Effect Of Bulk And Nano Metal Oxides, Ebru Karadağ, Selva Bi̇lge, Yusuf Osman Donar, Ali̇ Sinağ

Turkish Journal of Chemistry

In this study, olive oil residue (OR) biomass was pyrolyzed in the presence of bulk MgO (B-MgO), nano-MgO (N-MgO), bulk ZnO (B-ZnO)), and nano-ZnO (N- ZnO) metal oxides at different temperatures (400, 600, and 800 ºC). Significant results were obtained in terms of synthesis gas formation and CO2 reduction. The efficiency distribution of the products obtained as a result of the metal oxide-based pyrolysis process and the effects of metal oxides were examined in detail. Nanometal oxides were synthesized by the hydrothermal method. Characterization of metal oxides was carried out by Brunauer?Emmett?Teller (BET), x-ray powder diffraction (XRD) analysis and scanning-electron …

The Study On Biological Activities Of Silver Nanoparticles Produced Via Green Synthesis Method Using Salvia Officinalis And Thymus Vulgaris, Ömer Ödemi̇ş, Sadi̇n Özdemi̇r, Serpi̇l Gonca, Ali̇ Arslantaş, Mehmet Sali̇h Ağirtaş

Turkish Journal of Chemistry

In the present study, Ag nanoparticles (AgNPs) were synthesized from Salvia officinalis and Thymus vulgaris, known as phytotherapy plants. The obtained silver nanoparticles were characterized using SEM, XRD, FTIR, and UV/Vis spectra. The antioxidant capacities of Salvia officinalis-mediated AgNP (SO-AgNP) and Thymus vulgaris-mediated AgNP (TV-AgNP) were analyzed in vitro using 1,1-diphenyl-2-picrylhydrazyl and iron chelating activity assays. DPPH activities were 83.74% and 57.17% for SO-AgNP and TV-AgNP at concentration 200 mg/L, respectively. Both green synthesized AgNPs exhibited good iron chelating activity. In addition, the DNA cleavage activities of SO-AgNPs and TV-AgNP were investigated with agarose gel electrophoresis technique. …

Major Chemical Constituents From Illicium Griffithii Hook. F. & Thoms Of North East India And Their Cytotoxicity And Antimicrobial Activities, Deepjyoti Dutta, Bardwi Narzary, Snigdha Saikia, Kashyap J. Tamuli, Manobjyoti Bordoloi, Neipihoi Lhouvum, Shyamalendu Nath, Ranjan K. Sahoo, Barnali Gogoi, Surovi Saikia, Nayan K. Bhattacharyya

Turkish Journal of Chemistry

Illicium griffithii Hook. f. & Thoms is an endemic medicinal plant of North East India found in the Eastern Himalayan region of biodiversity mega centre. Herein, chemical investigation of I. griffithii, afforded five compounds and their structures were determined through extensive use of NMR, HRMS, and FT-IR spectroscopy. The complete proton-proton, proton-carbon coupling network of compound 1 was determined using 1H-1H COSY, HSQC and NOESY NMR experiments. All the compounds were evaluated for their cytotoxic activity by MTT assay and antimicrobial activity by Agar well diffusion method. Compound 1 exhibited significant cytotoxicity activity against Lung cancer (A549) and pancreatic …

A New Electrochromic Copolymer Composed Of 4,7-Di(Thiophen-2-Yl)Benzo[C] [1,2,5] Thiadiazole And 3,4-Ethylenedioxythiophene, Kübra Çeli̇k, Ari̇f Kivrak, Buket Çarbaş

Turkish Journal of Chemistry

A new electrochromic copolymer based on 4,7-di(thiophen-2-yl)benzo[c] [1,2,5]thiadiazole and 3,4-ethylenedioxythiophene was successfully obtained via the electrochemical polymerization method in the medium of electrolyte solution, which consists of 0.1 M tetrabutylammonium hexafluorophosphate and dichloromethane. In order to compare the electrochemical and chemical properties of the copolymer, the benzothiodiazole derivative and 3,4-ethylenedioxythiophene (EDOT) monomers, which are parts of the copolymer, are electrochemically polymerized, separately in the same environment and concentration with the copolymer. Poly(4,7-di(thiophen- 2-yl)benzo[c][1,2,5]thiadiazole) (P(TBT)) and poly(3,4-ethylenedioxythiophene) (PEDOT) polymers were obtained. Before starting the electrochemical synthesis, the initial oxidation potentials of the monomers that form the copolymer were compared via the …

Release Of Nifedipine, Furosemide, And Niclosamide Drugs From The Biocompatible Poly(Hema) Hydrogel Structures, Bahar Yilmaz

Turkish Journal of Chemistry

The primary aim of this article was to improve the solubility and bioavailability of the drugs nifedipine, niclosamide, and furosemide due to their poor solubility and dissolution rate. Therefore, these drugs require improvement in solubility and dissolution rate in formulation development, especially in solid dosage forms such as hydrogels and capsules. Hydrogel structures were synthesized by using a biocompatible, nontoxic, and protective pure 2-hydroxy ethyl methacrylate (HEMA) monomer. These hydrogel structures were characterized by various techniques such as scanning electron microscopy and Fourier-transformed infrared spectroscopy. In the next step, drug molecules were loaded in the poly (HEMA) hydrogels. Drug releases …

Insight Into Electrochemical Degradation Of Cartap (In Padan 95sp) By Boron-Doped Diamond Electrode: Kinetic And Effect Of Water Matrices, Hoang Nguyen

Turkish Journal of Chemistry

In this work, the kinetic electrochemical degradation of Cartap (CT) (in Padan 95 SP) at boron-doped diamond (BDD) electrode was investigated. This study indicated that the degradation of CT underwent both direct and indirect oxidations. Water matrices can either accelerate or inhibit the removal efficiency of CT: adding 15 mM Cl^- improved k_CT from 0.039 min^-1 to 0.054 min^-1 (increased by 38%), while k_CT decreased by 61.5% and 64% when increasing the concentration of HCO₃^- and humic acid (HA) to 15 mM and 15 mg L^-1, respectively. CT degradation was inhibited …

Virus Detection Using Bio-Based Analysis Systems: A Review Of Biorecognition Strategies, Nur Meli̇s Kiliç, Di̇lek Odaci Demi̇rkol

Turkish Journal of Chemistry

Infectious illnesses are on the rise in today's world, with serious consequences for animals, plants, and humans. Several infections, including the human immunodeficiency virus, affect a large number of individuals in various countries, particularly in the poorer portions of contemporary society, and continue to cause a variety of health problems. Viruses are tiny parasitic organisms. They are infectious agents that can only reproduce within a live cell of an organism. Viruses may infect any living organism. For clinical pointof- care applications, early detections for harmful agents such as bacteria, viruses are critical. The possibility of worldwide epidemics as a result …

Photocatalytic Degradation Of Paracetamol By Semiconductor Oxides Under Uv And Sunlight Illumination, Derman Akşi̇t, Güli̇n Selda Pozan Soylu

Turkish Journal of Chemistry

In this study, photocatalytic degradation of paracetamol (acetaminophen), an analgesic and antipyretic drug, was investigated in using semiconductors under UV-B and sunlight irradiation. Semiconductor materials, Bi₂O₃, ZnO, TiO₂, and ZrO₂, were prepared using simple sol-gel, coprecipitation, and microwave synthesis methods. These photocatalyts were characterized by various spectroscopic and other techniques. As a result of the reactions, 25 ppm paracetamol with Bi₂O₃ and ZnO photocatalyst, total degradation was achieved with UV-B irradiation in 90 min. The results of photocatalytic activities showed that the highest degradation rate was obtained with the …

Synthesis, Characterization, And Antimicrobial Evaluation Of Polyvinylalcohol-Osthol Composite Films, Ishrat Gowsia, Feroz Mir, Javid Banday

Turkish Journal of Chemistry

Although poly-vinyl alcohol (PVA) has certain mechanical drawbacks such as a weak barrier, it has widely been used in food packaging over the last many years. To increase the suitability of PVA (C₂H₄O)n and render it ideal for food packaging, a diversity of studies have already been carried out. In the below-mentioned script, we, for the first time, report the use of natural product osthol in making a new composite with PVA for enhancing thermal, physicochemical, and antimicrobial properties. The significant aim of the report is the insertion of osthol (C₁₅H₁₆O_{3 …}

Kinetic, Isotherm, And Thermodynamic Studies For Adsorptive Removal Of Basic Violet 14 From Aqueous Solution, Yasemi̇n Tamer, Hale Berber

Turkish Journal of Chemistry

In this study, the performance of chitosan based semi-IPN nanocomposite hydrogels for the adsorptive removal of basic violet 14 (BV14) from aqueous solution has been explored. Batch adsorption studies were conducted to determine the effect of various parameters on BV14 adsorption, and optimum values were reported as pH of 8, the adsorbent dosage of 0.025 g, initial BV14 concentration of 5 mg L^-1 and contact time of 90 min at a temperature of 25 °C. The semi-IPN hydrogel containing 0.5% by weight GO showed the improved adsorption capacity for BV14 compared to the neat hydrogel adsorbent, and the maximum …

Introducing An H113a Mutation Into Atg10 Y73q To Reduce Autophagic Activity And Understand The Effect Of Atg On Autophagosome Size And Number, Konrad L. Lautenschlager

Senior Honors Theses and Projects

Autophagy is an essential recycling process that occurs within eukaryotic cells, however, the individual functions of the current thirty-two known autophagic proteins are not yet entirely understood. At this time, it is known that the autophagic protein Atg7 works upstream of both Atg3 and Atg10. Atg3 is affected by Atg7 and allows for the attachment of Atg8 and the lipid PE which is part of the autophagosome membrane. The Atg10 pathway is also affected by Atg7 but attaches Atg12 to Atg5 which upregulates the function of Atg3 and ultimately Atg8 lipidation. These protein interactions are necessary for forming autophagosomes, large …

Inhibitors Of Alpha-Synuclein Aggregation, Jemil Ahmed

Electronic Theses and Dissertations

Alpha-Synuclein (αS) – a neuronal, disordered, presynaptic protein – aggregates into amyloid fibrils and accumulates in the substantia nigra pars compacta of Parkinson's Disease (PD) patients. The aggregation and accumulation of αS amyloid fibrils leads to death of dopaminergic neurons; a hallmark of PD. Although it’s not clear why αS aggregates, prior studies have found that intrastriatal injection of fibril alone is sufficient to cause PD pathology in mouse and non-human primates models. These observations implicate αS as a therapeutic target against PD.

Unfortunately, there are three caveats when attempting to target αS. First, αS is a neuronal protein expressed …

Dynamics And Turnover Of Lipid And Protein Domains In Cells And Supported Bilayers, Alan Weisgerber

Electronic Theses and Dissertations

Protein and lipid clustering is an important mechanism for cell processes such as exo- and endo-cytosis and creating functional signaling complexes. It has been seen that both lipids and proteins are involved with the formation of cluster domains on cell membranes, yet little is known about the interplay between the two. In this work I began with visualizing lipid sorting to artificially induced curvature in supported lipid bilayers, with lipid tails affecting the sorting differently to curvature. These results demonstrate that lipids sort to curvature on curved, supported lipid bilayers. The sorting depends on the number of lipids in the …

Directly Polymerizable Co Releasing Molecules, Jackson Snow

Electronic Theses and Dissertations

Despite the commonly held consensus that carbon monoxide (CO) is toxic, it has been shown to be an essential signaling molecule in the human neuronal system and has been noted to have anti-inflammatory properties, act as a vasodilator, have anti-proliferative impacts on tumors, and many other beneficial effects. The current limitation to using CO as a therapeutic molecule is delivering the proper dosages using CO releasing molecules (CORMs) without exhibiting toxicity. The first chapter of this thesis will review the biological significance of CO in biological systems, the limitations of existing CORMs, and the properties of diphenylcyclopropenone (DPCP) that make …

Chromatographic Studies Of Some Hormone And Metabolic Modulators Used For Doping In Sports, Ruth Marie Speidel

Online Theses and Dissertations

The World Anti-Doping Agency (WADA) is an international agency that monitors the use of Performance Enhancing Drugs (PEDs) in sports; their mission is “to lead a collaborative worldwide movement for doping-free sport” (Who We Are, 2022). For this mission, the WADA needs quick, sensitive, reproducible, and accurate methods for analyzing athletes’ biological fluids for possible PEDs. This research focuses on developing and validating simple, sensitive, rapid, and reliable gas chromatography- mass spectrometry (GC-MS) methods for the analysis of two hormone and metabolic modulators, toremifene and trimetazidine. Previously, there has been limited GC-MS methods used to analyze toremifene and trimetazidine. Quantification …

Developing A New Treatment For Superficial Fungal Infection Using Antifungal Collagen-Hsaf Dressing, Jing Zhong, Xiayi Yan, Xin Zuo, Xuan Zhao, Jiahui Yang, Qin Dou, Lulu Peng, Yuxiang Zhu, Yichen Xiao, Zeran Bian, Dalian He, Qiushuang Xu, Stephen Wright, Yaoyao Li, Liangcheng Du, Yan Wang, Jin Yuan

Chemistry Department: Faculty Publications

Fungal pathogens are common causes of superficial clinical infection. Their increasing drug resistance gradually makes existing antifungal drugs ineffective. Heat stable antifungal factor (HSAF) is a novel antifungal natural product with a unique structure. However, the application of HSAF has been hampered by very low yield in the current microbial producers and from extremely poor solubility in water and common solvents. In this study, we developed an effective mode of treatment applying HSAF to superficial fungal infections. The marine-derived Lysobacter enzymogenes YC36 contains the HSAF biosynthetic gene cluster, which we activated by the interspecific signaling molecule indole. An efficient extraction …

Detection And Identification Of Prevalent Cutting Agents In 'Street' Samples Utilizing Handheld And Benchtop Raman Spectroscopy And Surface-Enhanced Raman Spectroscopy (Sers), Nicole Kenny

Browse all Theses and Dissertations

Illicit and licit drugs continue to have a negative impact on the public’s health even with new regulations and laws. At local, state, and federal levels, crime laboratories analyze samples in a variety of mixtures and concentrations. Raman spectroscopy is a molecular fingerprinting, multiplex technique, which is considered a category A forensic characterization tool by the Scientific Working Group for the Analysis of Seized Drugs (SWGDRUG). The sensitivity of the Raman technique can be further enhanced down to the single-molecule detection level when analytes of interest are located at the interstitial sites of aggregated silver nanoparticles (i.e., the “hot spots” …

Biodiesel Production From Castor Oil: Mixing Optimization During Transestrification, Islam M. Al-Akraa

Chemical Engineering

No abstract provided.

Toward Liquid Cell Quantum Sensing: Ytterbium Complexes With Ultra-Narrow Absorption, Ashley J. Shin, Changling Zhao, Yi Shen, Claire E. Dickerson, Timothy Luke Atallah

Faculty Publications

No abstract provided.

Using Powder Diffraction To Give Insight Into Structures Of Ir2(Diisocyanomenthane)4x2 [Dimen] (X = Cl; Pf6; Bph4), Mairead Brownell

Scripps Senior Theses

Ir2(dimen)42+ (dimen = 1,8-diisocyanomenthane) has been studied extensively as model compound to better understand catalysis of photochemical reactions. Although Ir2(dimen)42+ has been used primarily to observe the photophysical changes of metal-metal transitions, it gives great insight into the transitions that allow other d8-d8 metal complexes to undergo photochemical processes and generate hydrogen gas. The large visible range by which Ir2(dimen)42+ (1) can be electronically excited in solution is indicative of its two solution phase ground states, which interestingly have been hypothesized to resemble two unique packing structures observed in the powder state. In this study, the powder diffraction patterns of …

Here, There, And Everywhere: Probing Ubiquitin-Cavitand Binding Via 15n-1h Hsqc, Julia Didziulis

Scripps Senior Theses

Ubiquitination and other post-translational modifications play a major role in the proliferation of many neurodegenerative diseases, developmental disorders, and cancers, and as such are subjects of recently increased biochemical interest. Expanding upon such research, this study confirmed a robust method of ubiquitin expression and purification, then used 15N-1H HSQC to analyze ubiquitin samples containing varying concentrations of a deep cavitand with affinity for lysine and arginine side chains. In the pure ubiquitin spectrum, arginine side chain chemical shifts were detected in the nitrogen 80-85 ppm range and lysine side chain signals were undetected. However, upon introduction of the cavitand, collection …

Analysis And Characterization Of Smokeless Powders And Smokeless Powder Residues, Emily Lennert

Electronic Theses and Dissertations, 2020-2023

The ability to associate a smokeless powder, smokeless powder residue, or organic gunshot residue (OGSR) to one another may be helpful in determining the origin of a suspected sample and aid in linking a suspect to a crime scene. In this study, smokeless powders were extracted and analyzed via gas chromatography – mass spectrometry (GC-MS) and direct analysis in real time – high resolution mass spectrometry (DART-HRMS). Subsequently, group definition was performed using hierarchical cluster analysis and principal component analysis followed by internally validated classification models. Then, smokeless powder residues were generated in-lab and extracted. Resulting residue data from each …

Polymer Derived Ceramic For Lithium-Ion Storage, And Electrospun Polyelectrolyte Fiber For Heavy Metal Ions Removal, Zeyang Zhang

Electronic Theses and Dissertations, 2020-2023

This dissertation includes two major projects. The first project investigated the great potential of polymer-derived ceramics (PDCs) as lithium-ion battery anode materials with good cycling stability and large capacity. SiCNO ceramic nanoparticles were produced by pyrolysis of polysilazane nanoparticles synthesized via an oil-in-oil emulsion crosslinking. The SiCNO nanoparticles had an average particle size of around 9 nm and contained graphitic carbon, Si3N4, and SiO2 domains. The electrochemical behavior of SiCNO nanoparticles anode was investigated to evaluate the Li-ion storage performance and understand its mechanism of Li-ion storage. The lithiation of SiCNO was observed at ~0.385 V versus Li/Li+. The anode …

Molecular Dynamics On Quantum Annealers, Igor Gaidai, Dmitri Babikov, Alexander Teplukhin, Brian K. Kendrick, Susan M. Mniszewski, Yu Zhang, Sergei Tretiak, Pavel A. Dub

Chemistry Faculty Research and Publications

In this work we demonstrate a practical prospect of using quantum annealers for simulation of molecular dynamics. A methodology developed for this goal, dubbed Quantum Differential Equations (QDE), is applied to propagate classical trajectories for the vibration of the hydrogen molecule in several regimes: nearly harmonic, highly anharmonic, and dissociative motion. The results obtained using the D-Wave 2000Q quantum annealer are all consistent and quickly converge to the analytical reference solution. Several alternative strategies for such calculations are explored and it was found that the most accurate results and the best efficiency are obtained by combining the quantum annealer with …

Mapping The Dna Damaging Effects Of Polypyridyl Copper Complexes With Dna Electrochemical Biosensors, Anna Banasiak, Nicolò Zuin Fantoni, Andrew Kellett, John Colleran

Articles

Several classes of copper complexes are known to induce oxidative DNA damage that mediates cell death. These compounds are potentially useful anticancer agents and detailed investigation can reveal the mode of DNA interaction, binding strength, and type of oxidative lesion formed. We recently reported the development of a DNA electrochemical biosensor employed to quantify the DNA cleavage activity of the well-studied [Cu(phen)₂]²⁺ chemical nuclease. However, to validate the broader compatibility of this sensor for use with more diverse—and biologically compatible—copper complexes, and to probe its use from a drug discovery perspective, analysis involving new compound libraries is …

Equivalence Of The Transition Heat Capacities Of Proteins And Dna, Matthew W. Eskew, Albert S. Benight

Chemistry Faculty Publications and Presentations

It has been reported for many globular proteins that the native heat capacity at 25°C, per gram, is the same. This has been interpreted to indicate that heat capacity is a fundamental property of native proteins that provides important information on molecular structure and stability. Heat capacities for both proteins and DNA has been suggested to be related to universal effects of hydration/solvation on native structures. Here we report on results from thermal denaturation analysis of two well-known proteins, human serum albumin and lysozyme, and a short DNA hairpin. The transition heat capacities at the Tm for the three molecules …