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Articles 7741 - 7770 of 33198

Full-Text Articles in Chemistry

Surface And Chemical Characteristics Of Platinum Modified Activated Carbon Electrodesand Their Electrochemical Performance, Tuğrul Yumak, Serap Yumak, Abdulkeri̇m Karabulut Jan 2021

Surface And Chemical Characteristics Of Platinum Modified Activated Carbon Electrodesand Their Electrochemical Performance, Tuğrul Yumak, Serap Yumak, Abdulkeri̇m Karabulut

Turkish Journal of Chemistry

Platinum (Pt) loaded activated carbons (ACs) were synthesized by the thermal decomposition of platinum (II) acetylacetonate (Pt(acac)2) over chemically activated glucose-based biochar. The effect of Pt loading on surface area, pore characteristics, surface chemistry, chemical structure, and surface morphology were determined by various techniques. XPS studies proved the presence of metallic Pt0 on the AC surface. The graphitization degree of Pt loaded ACs were increased with the loaded Pt0 amount. The electrochemical performance of the Pt-loaded ACs (Pt@AC) was determined not only by the conventional three-electrode system but also by packaged supercapacitors in CR2032 casings. The capacitive performance of Pt@AC …


Volatile Constituents Of Three Thymus Sipyleus Boiss. Subspecies From Different Sites In Turkey, Hale Gamze Ağalar, Mi̇ne Kürkçüoğlu, Kemal Hüsnü Can Başer, Kenan Turgut Jan 2021

Volatile Constituents Of Three Thymus Sipyleus Boiss. Subspecies From Different Sites In Turkey, Hale Gamze Ağalar, Mi̇ne Kürkçüoğlu, Kemal Hüsnü Can Başer, Kenan Turgut

Turkish Journal of Chemistry

This study was designed to reveal the chemical diversity of some Thymus sipyleus subspecies growing wild in Turkey and to compare the volatile compound profiles by using micro(hydro)distillation technique. For this purpose, volatile compounds isolated by microdistillation from nine samples (three plant samples collected from different regions in Antalya) of Thymus sipyleus Boiss. subsp. sipyleus var. sipyleus, T. sipyleus Boiss. subsp. sipyleus var. davisianus Ronniger, and T. sipyleus Boiss. subsp. rosulans (Borbas) Jalas were analyzed by GC and GC-MS systems. 1,8-Cineole, p-cymene, α-terpineol and carvacrol were identified as major compounds in T. sipyleus subsp. sipyleus var. sipyleus samples. Geranial, neral, …


In-Situ Synthesis Of Phthalocyanines On Electrospun Tio2 Nanofiber By Solvothermal Process For Photocatalytic Degradation Of Methylene Blue, Seli̇n Gümrükçü, Mukaddes Özçeşmeci̇, Esma Sezer, Belkiz Ustamehmetoğlu, Esi̇n Hamuryudan Jan 2021

In-Situ Synthesis Of Phthalocyanines On Electrospun Tio2 Nanofiber By Solvothermal Process For Photocatalytic Degradation Of Methylene Blue, Seli̇n Gümrükçü, Mukaddes Özçeşmeci̇, Esma Sezer, Belkiz Ustamehmetoğlu, Esi̇n Hamuryudan

Turkish Journal of Chemistry

Titanium dioxide/phthalocyanine (TiO2/Pc), TiO2/fluor containing phthalocyanine (TiO2/FPc), and TiO2/fluor containing cobalt phthalocyanine (TiO2/FCoPc) had been successfully fabricated by a simple combination of phthalocyanines obtained by in-situ synthesis on the surface of TiO2 nanofibers prepared by electrospinning. Scanning electron microscopy micrographs and X-ray diffraction analysis indicated that the phthalocyanines uniformly immobilized on the surface of TiO2 nanofibers. Photocatalytic activity of TiO2, TiO2/Pc, TiO2/FPc, TiO2/FCoPc nanofibers for methylene blue in water was comparatively investigated firstly by ultraviolet-visible absorption measurements with time, and kinetic parameters were calculated. Results indicated that the obtained TiO2/Pc, TiO2/FPc and TiO2/FCoPc exhibited high photocatalytic activity for the degradation …


The Application Of 13c Nmr And Untargeted Multivariate Analysis For Classifying Virgin Coconut Oil, Lolita G. Lagurin, Mark Joseph Garrovillas, Fabian M. Dayrit Jan 2021

The Application Of 13c Nmr And Untargeted Multivariate Analysis For Classifying Virgin Coconut Oil, Lolita G. Lagurin, Mark Joseph Garrovillas, Fabian M. Dayrit

Chemistry Faculty Publications

Virgin coconut oil (VCO) is produced from fresh mature coconut meat without the use of chemicals or high heat. VCO can be made using three processes: fermentation, centrifuge, and expeller. To determine quality, it is important to be able to differentiate control VCO (fresh) from old VCO, refined bleached and deodorized coconut oil (RBDCO), and VCO which has been adulterated with RBDCO. Differentiating these types of samples has remained a challenge because of their chemical similarity. This study investigated the ability of 13C NMR and multivariate analysis to differentiate these different coconut oil samples. The methodology used the standard 13C …


Philippine Medicinal Plants With Potential Immunomodulatory And Anti-Sars-Cov-2 Activities, Fabian M. Dayrit, Armando M. Guidote Jr, Nina Gloriani, Sheriah Laine M. De Paz-Silava, Irene M. Villaseñor, Rene Angelo S. Macahig, Mario A. Tan, John Ross N. Chua, Isidro C. Sia Jan 2021

Philippine Medicinal Plants With Potential Immunomodulatory And Anti-Sars-Cov-2 Activities, Fabian M. Dayrit, Armando M. Guidote Jr, Nina Gloriani, Sheriah Laine M. De Paz-Silava, Irene M. Villaseñor, Rene Angelo S. Macahig, Mario A. Tan, John Ross N. Chua, Isidro C. Sia

Chemistry Faculty Publications

Coronavirus disease 2019 (COVID-19) continues to devastate the world’s health and economy, affecting all aspects of life leading to widespread social disruption. Even as several vaccines have been developed, their availability in developing countries is limited and their efficacy against the variants of SARS-CoV-2 (severe acute respiratory syndrome–coronavirus 2) needs to be continuously assessed. The World Health Organization (WHO) has acknowledged that vaccines alone will not overcome the global challenges of COVID-19. Medicinal plants may provide the needed support. Herein, we identify Philippine medicinal plants that possess phytochemicals with potential anti-SARS-CoV-2 activity and/or immunomodulatory properties that may strengthen one’s immune …


Tri-Molybdenum Phosphide (Mo3P) And Multi-Walled Carbon Nanotube Junctions For Volatile Organic Compounds (Vocs) Detection, Baleeswaraiah Muchharla, Praveen Malali, Brenna Daniel, Alireza Kondori, Mohammad Asadi, Wei Cao, Hani E. Elsayed-Ali, Mickaël Castro, Mehran Elahi, Adetayo Adedeji, Kishor Kumar Sadasivuni, Muni Raj Mauya, Kapil Kumar, Abdennaceur Karoui, Bijandra Kumar Jan 2021

Tri-Molybdenum Phosphide (Mo3P) And Multi-Walled Carbon Nanotube Junctions For Volatile Organic Compounds (Vocs) Detection, Baleeswaraiah Muchharla, Praveen Malali, Brenna Daniel, Alireza Kondori, Mohammad Asadi, Wei Cao, Hani E. Elsayed-Ali, Mickaël Castro, Mehran Elahi, Adetayo Adedeji, Kishor Kumar Sadasivuni, Muni Raj Mauya, Kapil Kumar, Abdennaceur Karoui, Bijandra Kumar

Electrical & Computer Engineering Faculty Publications

Detection and analysis of volatile organic compounds’ (VOCs) biomarkers lead to improvement in healthcare diagnosis and other applications such as chemical threat detection and food quality control. Here, we report on tri-molybdenum phosphide (Mo3P) and multi- walled carbon nanotube (MWCNT) junction-based vapor quantum resistive sensors (vQRSs), which exhibit more than one order of magni- tude higher sensitivity and superior selectivity for biomarkers in comparison to pristine MWCNT junctions based vQRSs. Transmission electron microscope/scanning tunneling electron microscope with energy dispersive x-ray spectroscopy, x-ray diffraction, and x-ray photo- electron spectroscopy studies reveal the crystallinity and the presence of Mo and …


Simulation Studies On The Interactions Of Electron Beam With Wastewater, X. Li, S. Wang, Helmut Baumgart, G. Ciovati, F. Hannon Jan 2021

Simulation Studies On The Interactions Of Electron Beam With Wastewater, X. Li, S. Wang, Helmut Baumgart, G. Ciovati, F. Hannon

Electrical & Computer Engineering Faculty Publications

The manufactured chemical pollutants, like 1,4 dioxane and PFAS (per- and polyfluroralkyl substances), found in the underground water and/or drinking water are challenging to be removed or biodegraded. Energetic electrons are capable of mediating and removing them. This paper utilizes FLUKA code to evaluate the beam-wastewater interaction effects with different energy, space and divergence distributions of the electron beam. With 8 MeV average energy, the electron beam exits from a 0.0127 cm thick titanium window, travels through a 4.3 cm distance air and a second 0.0127 cm thick stainless water container window with 2.43 cm radius, and finally is injected …


The Potential For Remote Sensing Measurement Of Dissolved Organic Carbon As A Tool For Metal Risk Assessments, Mickey Nielsen Jan 2021

The Potential For Remote Sensing Measurement Of Dissolved Organic Carbon As A Tool For Metal Risk Assessments, Mickey Nielsen

Theses and Dissertations (Comprehensive)

The biotic ligand model (BLM) is a tool used to quantitatively evaluate how receiving water chemistry affects the bioavailability of metals. Sensitivity testing can be used to understand how the model outputs vary in response to systematic changes in water chemistry inputs. This will allow users of such models to understand how accurate their input parameters must be for a specified level of confidence in the output. Our focus was on dissolved organic carbon (DOC), which is often the most limiting data for application of BLM approaches to metals risk management. To potentially address DOC data limitations remote sensing can …


Influence Of Iceberg-Discharge Events On The Climate And Circulation Of The Central North Atlantic Ocean During The Last Glaciation, Ava Mcilvaine Jan 2021

Influence Of Iceberg-Discharge Events On The Climate And Circulation Of The Central North Atlantic Ocean During The Last Glaciation, Ava Mcilvaine

Scripps Senior Theses

The repeated occurrence of episodic iceberg-discharge events and abrupt climate change in the North Atlantic Ocean is well-documented for the late Quaternary period. However, much of the evidence for these periods known as Heinrich Events comes from the subpolar region, where deposition can be dominated by ice-rafted debris (IRD) and overwhelm other oceanographic and climatic indicators. Thus, the following analysis of coarse sediment from Integrated Ocean Drilling Program (IODP) Core Site U1313 (41°0.0'N, 32°57.42'W) evaluated ocean cooling related to ice-rafting, water mass migration, and climate change over the approximate last 100,000 years. Site U1313 is located near the North Atlantic …


“The Production Of Eight Plasmid Expression Vectors Through Gibson Assembly And The Optimization Of The Enzymatic Cleavage Reaction Between Tobacco Etch Virus (Tev) And The Model Fusion Protein, Nus-G”, Elizabeth Kennard Jan 2021

“The Production Of Eight Plasmid Expression Vectors Through Gibson Assembly And The Optimization Of The Enzymatic Cleavage Reaction Between Tobacco Etch Virus (Tev) And The Model Fusion Protein, Nus-G”, Elizabeth Kennard

Student Summer Scholars Manuscripts

Snake envenomization is a neglected public health issue that effects large portions of the world, as venomous snakes are found on six continents (World Health Organization,2007). With 2-3 million people bitten globally every year leading to an estimated 125,000 deaths and 400,000 amputations, researching effective treatments is important. Several Mammalian species have a natural resistance to snake venom (Voss, R.S et al.,2012; Bastos, V.A. et al.,2016). The North American Opossum (D. virginiana) produces proteins that inhibit certain snake venom components including snake venom metalloproteinases (SVMPs) and phospholipase 2As (PLA2s) (Catanese, J.J. et al.,1992; Perales, J. et al.,1994; Farah, M.D.F.L. et …


Dicer Represses The Interferon Response And The Double-Stranded Rna-Activated Protein Kinase Pathway In Mouse Embryonic Stem Cells, Chandan Gurung, Mona Fendereski, Krishna Sapkota, Jason Guo, Faqing Huang, Yan Lin Guo Jan 2021

Dicer Represses The Interferon Response And The Double-Stranded Rna-Activated Protein Kinase Pathway In Mouse Embryonic Stem Cells, Chandan Gurung, Mona Fendereski, Krishna Sapkota, Jason Guo, Faqing Huang, Yan Lin Guo

Faculty Publications

Recent studies have demonstrated that embryonic stem cells (ESCs) are deficient in expressing type I interferons (IFN), the cytokines that play key roles in antiviral responses. However, the underlying molecular mechanisms and biological implications of this finding are poorly understood. In this study, we developed a synthetic RNA-based assay that can simultaneously assess multiple forms of antiviral responses. Dicer is an enzyme essential for RNA interference (RNAi), which is used as a major antiviral mechanism in invertebrates. RNAi activity is detected in wild-type ESCs but is abolished in Dicer knockout ESCs (D-/-ESCs) as expected. Surprisingly, D-/-ESCs have gained the ability …


Direct Determination Of Absolute Stereochemistry Of Α-Methylselenocysteine Using The Mosher Method, Robert J. Wehrle, Douglas R. Powell, Douglas S. Masterson Jan 2021

Direct Determination Of Absolute Stereochemistry Of Α-Methylselenocysteine Using The Mosher Method, Robert J. Wehrle, Douglas R. Powell, Douglas S. Masterson

Faculty Publications

Mosher amides of α-methylselenocysteine were synthesized to determine the absolute stereochemistry of the sterically hindered α-carbon utilizing 1H, 13C, 19F, and 77Se NMR spectroscopies. After analysis of these spectra using the established Mosher method, the stereochemistry of the α-carbon was determined to be (R), which was subsequently confirmed using x-ray crystallography.


One-Pot Synthesis Of 2-Methylfurans From 3- (Trimethylsilyl)Propargyl Acetates Promoted By Trimethylsilyl Trifluoromethanesulfonate, Danielle E. Sklar, Alex V. Helbling, Yiqi Liu, C. Wade Downey Jan 2021

One-Pot Synthesis Of 2-Methylfurans From 3- (Trimethylsilyl)Propargyl Acetates Promoted By Trimethylsilyl Trifluoromethanesulfonate, Danielle E. Sklar, Alex V. Helbling, Yiqi Liu, C. Wade Downey

Chemistry Faculty Publications

In the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf) and triethylamine, 3-(trimethylsilyl)propargyl carboxylates undergo a one-pot alkylation-cyclization- desilylation reaction with ketones to produce 2-methylfurans. Alkylation at 0 °C in methylene chloride, followed by acid-catalyzed cyclization at room temperature, provides the furans in 52-86% yield. Cyclization and desilylation appear to be promoted by triflic acid generated in situ from the exposure of the reaction mixture to water upon completion of the initial substitution reaction.


Friedel–Crafts Addition Of Indoles To Nitrones Promoted By Trimethylsilyl Trifluoromethanesulfonate, Zachary Z. Oracheff, Helen L. Xia, Christopher D. Poff, Scott E. Isaacson, C. Wade Downey Jan 2021

Friedel–Crafts Addition Of Indoles To Nitrones Promoted By Trimethylsilyl Trifluoromethanesulfonate, Zachary Z. Oracheff, Helen L. Xia, Christopher D. Poff, Scott E. Isaacson, C. Wade Downey

Chemistry Faculty Publications

N-alkylindoles undergo Friedel–Crafts addition to aryl and secondary alkyl nitrones in the presence of trimethylsilyl trifluoromethanesulfonate and a trialkylamine to produce 3-(1- (silyloxyamino)alkyl)indoles. Spontaneous conversion to the bisindolyl(aryl)methanes, which is thermodynamically favored for nitrones derived from aromatic aldehydes, is suppressed under the reaction conditions. The silyloxyamino group can be deprotected with tetrabutylammonium fluoride to yield the hydroxylamine.


Biocompatible And Multifunctional Trityl Spin Probes For Electron Paramagnetic Resonance Spectroscopy, Teresa D. Gluth Jan 2021

Biocompatible And Multifunctional Trityl Spin Probes For Electron Paramagnetic Resonance Spectroscopy, Teresa D. Gluth

Graduate Theses, Dissertations, and Problem Reports (ETD)

The primary objective of my thesis was to develop and utilize a biocompatible multifunctional trityl spin probe for concurrent measurement of pO2, pHe, and [Pi] in vivo by electron paramagnetic resonance (EPR) spectroscopy (Chapter 2). My first goal was to synthesize the proposed probe we are terming HOPE71. Secondly, HOPE71 was characterized by X-band and L-band EPR spectroscopy. Next, the biocompatibility of HOPE71 was assessed through an albumin binding test, cytotoxicity assays, and in vivo intravenous tolerance. Then, the use of HOPE71 to measure the target parameters was demonstrated in a breast cancer …


Development Of Vibrating Sharp-Edge Spray Ionization (Vssi) Methods For Mass Spectrometry Analysis And Imaging, Nandhini Ranganathan Jan 2021

Development Of Vibrating Sharp-Edge Spray Ionization (Vssi) Methods For Mass Spectrometry Analysis And Imaging, Nandhini Ranganathan

Graduate Theses, Dissertations, and Problem Reports (ETD)

Mass Spectrometry (MS) is one of the widely used tools for chemical detection down to attomole concentrations for certain proteins. Ionization sources are a critical component for MS analysis. One of the major ionization methods is electrospray ionization (ESI), which remains a gold standard for proteins and peptides. ESI uses voltages up to ~4 kV to produce ions from solubilized molecules. Recently, a novel ionization method termed vibrating sharp-edge spray ionization (VSSI) that nebulizes liquids efficiently at the edge of a vibrating glass slide has been reported. The work in this thesis leverages the capabilities of VSSI for continuous flow-based …


Design And Synthesis Of Targeted Immunotherapeutic Agents, Md Shohel Rana Jan 2021

Design And Synthesis Of Targeted Immunotherapeutic Agents, Md Shohel Rana

Graduate Theses, Dissertations, and Problem Reports (ETD)

The therapeutic monoclonal antibodies are very important tools to fight against the diseases especially in the field of cancer immunotherapy. Many immunotherapeutic antibodies are being used to treat cancer that target multiple different components of the cancer microenvironment. Cells with extracellular juxtacrine ligands [JL-cells] and extracellular juxtacrine receptors [JR-cells] form JL-cell-JR-cell interfaces that produce juxtacrine signals inside JR-cells. [76] Juxtacrine signaling unlike endocrine or paracrine signaling requires no release or cellular uptake of ligands. [76] Immune checkpoint inhibitors are soluble IgG antibodies that block juxtacrine ligand engagements with juxtacrine receptors on tumor or other immune cells. [77] Rapid Nobel Prize …


Unique Biological Applications Of Charge Transfer Dissociation Mass Spectrometry, Halle M. Edwards Jan 2021

Unique Biological Applications Of Charge Transfer Dissociation Mass Spectrometry, Halle M. Edwards

Graduate Theses, Dissertations, and Problem Reports (ETD)

The ever-changing landscape of mass spectrometry is driven by gaps in knowledge, and one of the biggest driving forces is the desire to understand the structure and dynamics of biomolecules in living organisms. New and better methods of tandem mass spectrometry are often at the heart of technological developments. Some fragmentation methods are limited to expensive FTICR instruments, some techniques are limited multiply charged precursors, and others are limited to breaking only the weakest bonds in precursor ions; all of which support the pursuit of new activation methods. Charge transfer dissociation (CTD) addresses some of these concerns by providing structurally …


Online Ultra-High Performance Liquid Chromatography-Charge Transfer Dissociation-Mass Spectrometry (Uhplc-Ctd-Ms) Of Complex Mixtures Of Oligosaccharides, Praneeth M. Mendis Jan 2021

Online Ultra-High Performance Liquid Chromatography-Charge Transfer Dissociation-Mass Spectrometry (Uhplc-Ctd-Ms) Of Complex Mixtures Of Oligosaccharides, Praneeth M. Mendis

Graduate Theses, Dissertations, and Problem Reports (ETD)

Abstract

Online Ultra-High Performance Liquid Chromatography-Charge Transfer Dissociation-Mass Spectrometry (UHPLC-CTD-MS) of Complex Mixtures of Oligosaccharides

Praneeth M. Mendis

Complex carbohydrates make up more than half the biomass on earth, and they are crucial to a wide range of processes in living organisms. When polysaccharides and glycans are enzymatically digested into manageable units called oligosaccharides, they typically consist of 2-20 linear or branched sugar units. The detailed structural analysis of oligosaccharides assists in the identification of structural and chemical properties of the polymers from which they derive. Tandem mass spectrometry (MS/MS) is a key technique used in oligosaccharides structural characterization. Within …


Modified Firearm Discharge Residue Analysis Utilizing Advanced Analytical Techniques, Complexing Agents, And Quantum Chemical Calculations, William J. Feeney Jan 2021

Modified Firearm Discharge Residue Analysis Utilizing Advanced Analytical Techniques, Complexing Agents, And Quantum Chemical Calculations, William J. Feeney

Graduate Theses, Dissertations, and Problem Reports (ETD)

The use of gunshot residue (GSR) or firearm discharge residue (FDR) evidence faces some challenges because of instrumental and analytical limitations and the difficulties in evaluating and communicating evidentiary value. For instance, the categorization of GSR based only on elemental analysis of single, spherical particles is becoming insufficient because newer ammunition formulations produce residues with varying particle morphology and composition. Also, one common criticism about GSR practitioners is that their reports focus on the presence or absence of GSR in an item without providing an assessment of the weight of the evidence. Such reports leave the end-used with unanswered questions, …


The Effects Of Nacl On The Triple Helix Structure Of Collagen And The Reinforcement Of Tung Oil-Based Polymers With Collagen Peptides, Christopher Dzorkpata Jan 2021

The Effects Of Nacl On The Triple Helix Structure Of Collagen And The Reinforcement Of Tung Oil-Based Polymers With Collagen Peptides, Christopher Dzorkpata

College of Graduate Studies: Theses & Dissertations

In this research, a collagen-reinforced bio-composite from tung oil was prepared using free radical initiation and thermal polymerization, leading to polyolefinic tung oil-based matrix. Two peptides (long and short) were synthesized and their secondary features were analyzed using circular dichroism spectroscopy. After this analysis, the long peptide exhibited more triple helix characteristics as compared to the short peptide. The full protein will ultimately have a better interaction with the tung oil, was used in the synthesis of the collagen-reinforced bio-composite. The presence of NaCl in the triple helix and its overall effect on the thermal and mechanical properties of the …


Hydroamidation With Acetamides And Trifluoroacetamides, Gordon H. Whitetree Jan 2021

Hydroamidation With Acetamides And Trifluoroacetamides, Gordon H. Whitetree

College of Graduate Studies: Theses & Dissertations

The hydroamidation reaction is an attractive methodology for the construction of larger functional molecules. In our research, a baseline reactivity was established for the hydroamidation reaction using a set of N-alkyl and N-aryl (trifluoro)acetamides with methyl acrylate and acrylonitrile, various bases and varying reaction conditions. The combination of alkenes, acetamides, and trifluoroacetamides with base was crucial for reaction rate. N-aryl trifluoroacetamides exhibited near quantitative conversions in neat alkene with Diazabicycloundecene (DBU) as base. The less acidic N-aryl acetamides performed much faster in the presence of KOtBu and conversions of >95% were accomplished regularly but contained a large presence …


Advancements In Bio-Based Novel (Co)Monomers For Polymeric Materials, Khristal Anne Monroe Jan 2021

Advancements In Bio-Based Novel (Co)Monomers For Polymeric Materials, Khristal Anne Monroe

College of Graduate Studies: Theses & Dissertations

Most current research in the area of sustainable and environmentally friendly materials relate to the use of renewable sources for the fabrication of bio-based polymers and composites. Using plant-based derivatives is a common strategy. Pine sap can be distilled into turpentines (light fraction) and pine rosin (heavy fraction). Pine rosin is obtained as a brittle solid and its major component is abietic acid. This project aims at investigating a synthetic approach for the synthesis of a pine rosin-based polymer that can be potentially used for manufacturing a collection device for pine sap. The synthetic strategy consisted in the preparation of …


Investigation Of Performances Of Commercial Diesel Oxidation Catalysts For Co, C3h6, And No Oxidation, Hande Güneş, Deni̇z Şanli Yildiz, Hüseyi̇n Barkin Özener, Gökhan Hi̇sar, Selmi̇ Eri̇m Bozbağ, Can Erkey Jan 2021

Investigation Of Performances Of Commercial Diesel Oxidation Catalysts For Co, C3h6, And No Oxidation, Hande Güneş, Deni̇z Şanli Yildiz, Hüseyi̇n Barkin Özener, Gökhan Hi̇sar, Selmi̇ Eri̇m Bozbağ, Can Erkey

Turkish Journal of Chemistry

Four commercial monolithic diesel oxidation catalysts (DOCs) with two different platinum group metal (PGM) loadings and Pt:Pd ratios of 1:0, 2:1, 3:1 (w/w) were investigated systematically for CO, C3H6, and NO oxidation, CO-C3H6 co-oxidation, and CO-C3H6-NO oxidation reactions via transient activity measurements in a simulated diesel engine exhaust environment. As PGM loading increased, light-off curves shifted to lower temperatures for individual and co-oxidation reactions of CO and C3H6. CO and C3H6 were observed to inhibit the oxidation of themselves and each other. Addition of Pd to Pt was found to enhance CO and C3H6 oxidation performance of the catalysts while …


Novel Mixed Ligand Coordination Compounds Of Some Rare Earth Metal Cations Containing Acesulfamato/N,N-Diethylnicotinamide, Leri̇man Zeybel, Dursun Ali̇ Köse Jan 2021

Novel Mixed Ligand Coordination Compounds Of Some Rare Earth Metal Cations Containing Acesulfamato/N,N-Diethylnicotinamide, Leri̇man Zeybel, Dursun Ali̇ Köse

Turkish Journal of Chemistry

The mixed ligand coordination compounds containing acesulfamato and N,N-diethylnicotinamide biomolecules of some rare earth metal cations (Eu3+, Tb3+, Ho3+, Er3+ and Yb3+) were synthesized, and their structural properties were investigated. Possible structural formulas have been proposed by determining the chemical composition of molecules (elemental analysis), binding properties (infrared spectroscopy, mass analysis, solid-state UV-vis spectroscopy), thermal degradation properties (TGA / DTA curves). Based on the data collected, it is suggested that rare earth metal cations with a 3+ oxidation state have sextet coordination. The geometries of the structures were thought to be distorted octahedral. The charge balance of the coordination sphere …


Binding Of Permanganate Anion To Pentaammineazidocobalt(Iii) Cation In Solution And Solid Phases: Synthesis, Characterization, X-Ray Structure, And Genotoxic Effects Of [Co(Nh3)5n3](Mno4)2•H2o, Ritu Bala, Jinkwon Kim, Vinit Prakash Jan 2021

Binding Of Permanganate Anion To Pentaammineazidocobalt(Iii) Cation In Solution And Solid Phases: Synthesis, Characterization, X-Ray Structure, And Genotoxic Effects Of [Co(Nh3)5n3](Mno4)2•H2o, Ritu Bala, Jinkwon Kim, Vinit Prakash

Turkish Journal of Chemistry

A pentaammineazidocobalt(III) complex, [Co(NH3)5N3](MnO4)2XH2O has been synthesized by an one-pot synthesis method. It was characterized by studies such as infrared (IR) and UV-visible spectroscopy. The single crystal X-ray structure analysis revealed that the title complex crystallizes in space group Cc. The cobalt center is six coordinated with slightly octahedral geometry. The supramolecular architecture is also formed by intermolecular N-H…O (anion and H2O) and Mn-O…O-H hydrogen bonds. The binding property of the cation, [Co(NH3)5N3]2+ with the anion, MnO4- has also been determined (in solution phase) with the help of UV-visible spectroscopic titrations. Further, the genotoxic effects of KMnO4, [Co(NH3)5N3]Cl2 and [Co(NH3)5N3](MnO4)2XH2O …


Impact Of Graphitic Carbon Nitrides Synthesized From Different Precursors On Schottky Junction Characteristics, Orhan Altan Jan 2021

Impact Of Graphitic Carbon Nitrides Synthesized From Different Precursors On Schottky Junction Characteristics, Orhan Altan

Turkish Journal of Chemistry

Graphitic carbon nitride (g-CN) has gained wide interest in many areas, such as energy and the environmental remediation as a layered polymeric semiconductor that allows the formation of catalytically active Schottky junctions due to its proper electronic band structure. Interestingly, although it is known that the precursors used in the synthesis, can influence the properties of the g-CN, no detailed study on these effects on Schottky junctions could be found in the literature. In this research, the effects of g-CNs synthesized by thermal polycondensation of different precursors on the photocatalytic efficiency of Schottky junctions were investigated. For this purpose, urea, …


Fabrication And Characterization Of Enhanced Hydrazine Electrochemical Sensor Based On Gold Nanoparticles Decorated On The Vanadium Oxide, Ruthenium Oxide Nanomaterials, And Carbon Nanotubes Composites, Si̇bel Karaca, Süleyman Koçak Jan 2021

Fabrication And Characterization Of Enhanced Hydrazine Electrochemical Sensor Based On Gold Nanoparticles Decorated On The Vanadium Oxide, Ruthenium Oxide Nanomaterials, And Carbon Nanotubes Composites, Si̇bel Karaca, Süleyman Koçak

Turkish Journal of Chemistry

This work describes the synthesis of mixed oxide film of vanadium and ruthenium by pulsed deposition technique on multiwall carbon nanotubes and the decoration of gold nanoparticles on the mixed film. A ternary electrocatalyst has been developed for the electrochemical oxidation of hydrazine by combining two metal oxide mixtures with Au nanoparticles. Surface morphology and chemical composition of the electrode have been examined with SEM, EDX, HRTEM, EIS, and XRD. The peak current of hydrazine increased 9 times at the AuNPs/(VOx-RuOx)/CNT/GCE compared to the bare GCE, and the peak potential shifted to negative 848 mV. Linear sweep voltammetry (LSV) and …


Structural And Adsorption Behaviour Of Zno/Aminated Swcnt-Cooh For Malachite Green Removal: Face-Centred Central Composite Design, Zeynep Ci̇ğeroğlu Jan 2021

Structural And Adsorption Behaviour Of Zno/Aminated Swcnt-Cooh For Malachite Green Removal: Face-Centred Central Composite Design, Zeynep Ci̇ğeroğlu

Turkish Journal of Chemistry

In this study, an effective adsorbent was synthesized to remove malachite green (MG), which is one of the toxic dyes. Firstly, single walled carbon nanotube with carboxylated acid (SWCNT-COOH) was functionalized with diethylenetriamine and a new nanocomposite was obtained using nano zinc oxide (ZnO) powder. The effects of pH (3-7), the amount of adsorbent (5-15 mg) and the initial concentration (10-50 mg L-1) of the solution on the adsorption uptake were investigated. The optimal parameters that maximize the adsorption uptake according to the specified working range are found to be 4.63 for pH, 49.94 mg L-1 for initial concentration, 5.25 …


Catalytic, Theoretical, And Biological Investigation Of An Enzyme Mimic Model, Gülci̇han Gülseren Jan 2021

Catalytic, Theoretical, And Biological Investigation Of An Enzyme Mimic Model, Gülci̇han Gülseren

Turkish Journal of Chemistry

Artificial catalyst studies were always stayed at the kinetics investigation level, in this work bioactivity of designed catalyst were shown by the induction of biomineralization of the cells, indicating the possible use of enzyme mimics for biological applications. The development of artificial enzymes is a continuous quest for the development of tailored catalysts with improved activity and stability. Understanding the catalytic mechanism is a replaceable step for catalytic studies and artificial enzyme mimics provide an alternative way for catalysis and a better understanding of catalytic pathways at the same time. Here we designed an artificial catalyst model by decorating peptide …