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Articles 6121 - 6150 of 33164

Full-Text Articles in Chemistry

Single And Selective Transport Of Zr(Iv) Ions With Trioctyl Amine Dissolved In Kerosene Using A Multidropped Liquid Membrane Technique, Fatma Tezcan, Ramazan Donat Jan 2022

Single And Selective Transport Of Zr(Iv) Ions With Trioctyl Amine Dissolved In Kerosene Using A Multidropped Liquid Membrane Technique, Fatma Tezcan, Ramazan Donat

Turkish Journal of Chemistry

It is very important to develop a process for selectively extracting Zr(IV) ions from the solution medium to produce zirconium metal used in industry and nuclear reactors. In this study, the parameters affecting the extraction of Zr(IV) ions were investigated using a multidropped liquid membrane (MDLM) system. Trioctyl amine (TOA) dissolved in kerosene was used as a carrier ligand in the extraction of Zr(IV) ions by the MDLM technique. The effect of carrier concentration and stripping solution concentration, pH, and the temperature in the donor phase on the transport of Zr(IV) were investigated. The optimum condition for the transportation of …

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A Study Of Silicon And Germanium-Based Molecules In Terms Of Solar Cell Devices Performance, Emi̇ne Taniş Jan 2022

A Study Of Silicon And Germanium-Based Molecules In Terms Of Solar Cell Devices Performance, Emi̇ne Taniş

Turkish Journal of Chemistry

Photovoltaic energy sources are increasingly in demand due to the cost of petroleum fuels and concerns about carbon emissions. For this reason, it is important to determine the photovoltaic properties of the compounds that are thought to be suitable for these energy sources. Here, 1,1,2,3,4,5-Hexaphenyl-1H-silole (HPS) and 1,1,2,3,4,5-Hexaphenyl-1H-germole (HPG) compounds that are thought to have excellent photovoltaic properties, electronic and charge transport properties were investigated experimentally and theoretically. The total energies, absorption spectra, Fermi energy (Efl) and work function (φ), maximum open circuit voltage (VOC), reorganization energies (λe and λh), frontier molecular orbital …

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Parameter Effect Quantification For A Phase Change Material-Based Lithium-Ion Battery Thermal Management System, Uğur Morali Jan 2022

Parameter Effect Quantification For A Phase Change Material-Based Lithium-Ion Battery Thermal Management System, Uğur Morali

Turkish Journal of Chemistry

The influence of discharge rate, ambient temperature, and phase change material on the maximum temperature and the highest temperature difference was investigated. The maximum temperature of the battery was tested with and without phase change material under extreme discharge rates (4C and 5C) and ambient temperatures (310 K and 320 K). Results showed that a phase change material reduced the maximum temperature from 327.94 K to 306.45 K for a 14.6 Ah lithium-ion battery discharged at 5C-rate and 320 K. Quantitatively determined parameter effects revealed that the PCM parameter considerably had a remarkable influence on maximum temperature compared to discharge …

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L-(+)-Tryptophan Methyl Ester Derived Polymeric Microbeads As An Efficient Heterogeneous Catalyst For Green Synthesis Of 2-Amino-4-(Nitromethyl)-4h-Chromene-3- Carbonitriles, Ayşe Haliç Poslu, Bi̇lgen Osman, Yunus Kaya, Ömer Koz, Gamze Koz Jan 2022

L-(+)-Tryptophan Methyl Ester Derived Polymeric Microbeads As An Efficient Heterogeneous Catalyst For Green Synthesis Of 2-Amino-4-(Nitromethyl)-4h-Chromene-3- Carbonitriles, Ayşe Haliç Poslu, Bi̇lgen Osman, Yunus Kaya, Ömer Koz, Gamze Koz

Turkish Journal of Chemistry

The cross-linked microbeads with average diameter of 106-300 μm, [poly(EGDMA-MATrp)], were obtained by copolymerization reaction of N-methacryloyl-L-(+)-tryptophan methyl ester (MATrp) with ethylene glycol dimethacrylate (EGDMA) and successfully applied as a heterogeneous catalyst in conjugate addition reaction of nitromethane to substituted 2-iminochromenes in aqueous media. A variety of 2-amino-4-(nitromethyl)-4H-chromene-3-carbonitriles has been synthesized in good yields. Polymeric microbeads were very durable and reused 5 times without a significant loss of activity. DFT calculations and experimental results revealed the significant role of π-π interactions as well as hydrogen bonding in the reaction mechanism.

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Moo3, Tio2, And Motio5 Based Oxide Semiconductor For Photovoltaic Applications, Fatma Bayrakçeken Jan 2022

Moo3, Tio2, And Motio5 Based Oxide Semiconductor For Photovoltaic Applications, Fatma Bayrakçeken

Turkish Journal of Chemistry

Topographic essential synthesis of nanomaterials by adjusting easy preparatory factors is an effective way to improve a variety of nanostructured materials. The SILAR technique is used to evaluate the manufacturing samples of MoO3, TiO2, and MoTiO5 nanostructures. These nanostructures of MoO3, TiO2, and MoTiO5 are used as electrode materials in photovoltaic systems. The link between photoelectrochemical characteristics and MoO3, TiO2, and MoTiO5 nanostructures is studied in depth. The photoelectrochemical characteristics of MoO3, TiO2, and MoTiO5 nanostructures are discovered to be …

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Synthesis And Characterization Of A Series Of Conducting Polymers Based On Indole And Carbazole, Mehmet Ergi̇ner, Belkis Ustamehmetoğlu, Esma Sezer Jan 2022

Synthesis And Characterization Of A Series Of Conducting Polymers Based On Indole And Carbazole, Mehmet Ergi̇ner, Belkis Ustamehmetoğlu, Esma Sezer

Turkish Journal of Chemistry

A series of indole (In) and carbazole (Cz) derivative monomers have been synthesized, such as 4-[3-carbazolyl] indole (4In-3Cz), 5-[3-carbazolyl] indole (5In-3Cz), 6-[3-carbazolyl] indole (6In-3Cz), 7-[3-carbazolyl] indole (7In-3Cz). The comonomers synthesized by Stille coupling reaction were characterized by 1H-NMR and elemental analysis. Potentiodynamic method was used for electropolymerization of comonomers, Indole, Cz, and the mixture of In and Cz. Electrochemical activities of resulting P[4In-3Cz], P[5In-3Cz], P[6In-3Cz], P[7In-3Cz], polyindole (PIn), polycarbazole (PCz) and P[In-co-Cz] films were investigated comparatively by CV at different scan rates, electrochemical impedance spectroscopy (EIS) and spectroelectrochemical measurements. The ionization potentials, Ip, specific capacitance, Csp, and optical band gap, …

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Ytterbium Oxide Nanofibers: Fabrication And Characterization For Energy Applications, Adem Sarilmaz Jan 2022

Ytterbium Oxide Nanofibers: Fabrication And Characterization For Energy Applications, Adem Sarilmaz

Turkish Journal of Chemistry

Metal oxide nanomaterials are widely used in many applications of renewable energy. Ytterbium oxide (Yb2O3) also attracts attention due to its similar structure to ZnO (~3,26 eV) and TiO2 (~3,36 eV) in terms of bandgap energy. In this study, Yb2O3 belonging to the lanthanide oxide family was produced as nanofiber forms by using the electrospinning technique, which allows for large-scale production, for the first time. The morphological, structural, optical, and phase properties of the produced nanofibers were investigated via XRD, SEM-Mapping, TEM, FTIR, UV-Vis, and XPS characterization techniques. As a result of …

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The Effect Of A Phosphorus-Based Fr On The Fire Performance And Flammability Properties Of Basalt Fiber-Reinforced Acrylonitrile-Butadiene-Styrene Composites, Çağrialp Arslan, Mehmet Doğan Jan 2022

The Effect Of A Phosphorus-Based Fr On The Fire Performance And Flammability Properties Of Basalt Fiber-Reinforced Acrylonitrile-Butadiene-Styrene Composites, Çağrialp Arslan, Mehmet Doğan

Turkish Journal of Chemistry

This study focuses on the improvement in fire performance, and flame retardancy (FR) properties of chopped basalt fiberreinforced acrylonitrile-butadiene-styrene (ABS) composites. For this purpose, different amounts of aluminum diethyl phosphinate (AlPi) compound (5, 10, and 15 wt%) were incorporated in the composites. The FR properties of the composites were examined via limiting oxygen index (LOI), UL-94 standard, and mass loss calorimeter tests. Thermogravimetric analysis was carried out to analyze the decomposition behavior of the composites. SEM inspection was also performed to examine the char surfaces of the composites. The results and findings showed that the introduction of AlPi compound into …

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Release Of Nifedipine, Furosemide, And Niclosamide Drugs From The Biocompatible Poly(Hema) Hydrogel Structures, Bahar Yilmaz Jan 2022

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 …

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Assessment Of Environmental Pollutants At Trace Levels Using Ionic Liquids-Based Liquid-Phase Microextraction, Furkan Uzcan, Muhammad Saqaf Jagirani, Mustafa Soylak Jan 2022

Assessment Of Environmental Pollutants At Trace Levels Using Ionic Liquids-Based Liquid-Phase Microextraction, Furkan Uzcan, Muhammad Saqaf Jagirani, Mustafa Soylak

Turkish Journal of Chemistry

Sample preparation is the crucial and most challenging part of analytical chemistry for the speciation of environmental pollutants' traces. Along with the development of the sample preparation methods, the ionic liquid-based microextraction technique plays an important role. Due to the unequivocally unique "green" characteristic of ionic liquids (ILs), they owe their tunable properties, such as highly selective and high reaction efficiency, reusability, and good thermal stability, to present advancements in the sample preparation process. The ionic liquid-based microextraction techniques miniaturize the sample preparation process. Liquid phase microextraction intermediate solvents, desorption solvent extractants, and mediators have been used. They are quoting …

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Chemical Compositions And Biological Activities Of The Oils From The Genus Taxus And Factors Limiting The Regeneration Of Endangered Yews: A Review, Sagar Dhakal, Prem Kumar Khosla, Tokuma Getahun Jan 2022

Chemical Compositions And Biological Activities Of The Oils From The Genus Taxus And Factors Limiting The Regeneration Of Endangered Yews: A Review, Sagar Dhakal, Prem Kumar Khosla, Tokuma Getahun

Turkish Journal of Chemistry

The genus Taxus (yews) is the largest genus of the family Taxaceae. It comprises about 24 species with 55 varieties distributed mainly in Asia, Europe, North Africa, and North America. In addition to the taxane diterpenoids and the cancer drug taxol, its species contain many essential oils with actual or potential biological activity. This review covers the chemical constituents as well as biological activities of these oils that have been studied in fourteen countries over 46 years (1975-2021). It also discusses the biotic and abiotic factors that limit the regeneration of these economically and medicinally important plants.

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Virus Detection Using Bio-Based Analysis Systems: A Review Of Biorecognition Strategies, Nur Meli̇s Kiliç, Di̇lek Odaci Demi̇rkol Jan 2022

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 …

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Silver Nanoparticles (Agnps) Based Selective Colorimetric Sensor For The Detection Of D-Arabinitol In A Urine Sample, Yuni Retnaningtyas, Siswandono Siswodihardjo, Ari Satia Nugraha Jan 2022

Silver Nanoparticles (Agnps) Based Selective Colorimetric Sensor For The Detection Of D-Arabinitol In A Urine Sample, Yuni Retnaningtyas, Siswandono Siswodihardjo, Ari Satia Nugraha

Turkish Journal of Chemistry

D-arabinitol is a sugar alcohol that is a typical metabolite of Candida species. The hydroxy group owned by D-arabinitol can function as a reducing agent that can reduce Ag+ to AgNPs. The resulting colloid is further stabilized by the addition of a capping agent. The capping agent used in this study was a combination of chitosan 1%(w/w) and PEG 6000 1% (w/w) (2:1) v/v. The formation of AgNPs causes an increase in the surface plasmon resonance spectra of the colloid solution at a wavelength of 430 nm with a slight blue shift. At the same time, the color of …

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Design, Synthesis, And Greener Pasture Biological Assessment Of A Novel Nucleoside: 1-(Α-D-Ribofuranosyl)-6,7-Difluoro-2-Methyl-4-Quinazolinone As An Inhibitor Of Covid-19 And Alzheimer's Disease, Laila M. Break, Adil A. Gobouri, Wafa S. Al-Harthi, Mohamed Hagar, Nadia S. Alkaff, Musa A. Said Jan 2022

Design, Synthesis, And Greener Pasture Biological Assessment Of A Novel Nucleoside: 1-(Α-D-Ribofuranosyl)-6,7-Difluoro-2-Methyl-4-Quinazolinone As An Inhibitor Of Covid-19 And Alzheimer's Disease, Laila M. Break, Adil A. Gobouri, Wafa S. Al-Harthi, Mohamed Hagar, Nadia S. Alkaff, Musa A. Said

Turkish Journal of Chemistry

Synthesis of a new fluorinated nucleoside of 6,7-difluoro-2-methyl-4-quinazolinone was described. 2-Amino-4,5-difluorobenzoic acid 1 reacts with (CH3CO)2O followed by ammonia to form (1H)-6,7-difluoro-2-methyl-4-quinazolinone 3a. Ribosylation of a silylated 4 with l-O-acety1-2,3-5-tri-O-benzoyl-α-D-ribofuranose 5 forms a protected nucleoside 6 then unprotected from 6 to give a free nucleoside 7. Greener pasture biological docking of the cystine protease of COVID-19 [Mpro, code 7BQY, PDB] by novel nucleoside and fluoroquinazoline compounds is presented. LIGPLOT (2D) representations calculated for the same ligands are shown. A superposition of remdesivir approved medicine, N3 inhibitor, and our ligands docked …

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A Molecularly Imprinted Polymer As Solid Phase Extraction Sorbent For Ketoprofen Determination In Water And Artificial Serum Prior To Hplc, Eli̇f Gürel Özyurt, Ömer Özyurt, Yekta Arya Ölçer Altinsoy, Ahmet Emi̇n Eroğlu, Ezel Boyaci, Talal Shahwan Jan 2022

A Molecularly Imprinted Polymer As Solid Phase Extraction Sorbent For Ketoprofen Determination In Water And Artificial Serum Prior To Hplc, Eli̇f Gürel Özyurt, Ömer Özyurt, Yekta Arya Ölçer Altinsoy, Ahmet Emi̇n Eroğlu, Ezel Boyaci, Talal Shahwan

Turkish Journal of Chemistry

Ketoprofen (KET) is an active pharmaceutical compound that has pain relieving and antipyretic effects. Its determination in body fluids and environmental waters is important due to widespread use of the compound. In this study, a selective and reliable method has been developed for the determination of ketoprofen in water and artificial serum using molecularly imprinted polymers (MIPs) as a solid phase extraction sorbent prior to HPLC-DAD detection. The MIP was synthesized by copolymerization of methacrylic acid (MAA) and trimethylpropane trimethacrylate (TRIM) in the presence of ketoprofen as the template. For the sake of comparison, nonimprinted polymer (NIP) was also synthesized …

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Photocatalytic Degradation Of Paracetamol By Semiconductor Oxides Under Uv And Sunlight Illumination, Derman Akşi̇t, Güli̇n Selda Pozan Soylu Jan 2022

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 …

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The Sweet And Embellishing Lycium Arabicum Schweinf. Ex Boiss. Fruit Oil: A Potential Source Of Essential Ω-6 And Ω-9 Fatty Acids, Phytosterols, And Carotenoids, Jawhar Fakhfakh, Marwa Affes, Hazem Jabeur, Mohamed Ayadi, Noureddine Allouche Jan 2022

The Sweet And Embellishing Lycium Arabicum Schweinf. Ex Boiss. Fruit Oil: A Potential Source Of Essential Ω-6 And Ω-9 Fatty Acids, Phytosterols, And Carotenoids, Jawhar Fakhfakh, Marwa Affes, Hazem Jabeur, Mohamed Ayadi, Noureddine Allouche

Turkish Journal of Chemistry

In our current phytochemical investigation on the Tunisian plant Lycium arabicum Schweinf. ex Boiss., we attempted to explore the oil obtained from its fruits. This oil was extracted by cold maceration with ethanol and was analyzed to estimate its sterol and fatty acid content. The physicochemical parameters of the oil were also examined. They were specified in terms of acid value (0.8 ± 0.01 mg KOH g-1 oil), peroxide value (10.9 ± 0.02 meq O2 kg-1 oil), saponification value (162.97 ± 0.03 mg KOH g-1 oil), chlorophylls (1.011 ± 0.03 mg kg-1 oil) and carotenoids …

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Study On Moo3/Sba-16 Catalyzed Transesterification To Synthesize Diphenyl Carbonate, Ying Li, Shunwu He Jan 2022

Study On Moo3/Sba-16 Catalyzed Transesterification To Synthesize Diphenyl Carbonate, Ying Li, Shunwu He

Turkish Journal of Chemistry

In this paper, the mesoporous molecular sieve SBA-16 with good dispersion was prepared by hydrothermal method. Under the condition of Si/Mo= 1.0, MoO3/SBA-16 catalysts were prepared by iso-dipping method at 550 °C, 650 °C and 750 °C calcination temperature, which for the synthesis of diphenyl carbonate (DPC) from dimethyl carbonate (DMC) and phenyl acetate (PA) was used, and the uncalcined MoO3/SBA-16 was used as a reference. XRD, TG-DTA, XPS, ICP-MS, FT-IR, BET, SEM and TEM characterization. The effects of calcination temperature and reaction conditions on the catalytic performance of MoO3/SBA-16 in transesterification of DMC and PA …

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Miscibility And Thermal Behavior Of Poly(Methyl Methacrylate) And Polystyrene Blend Using Benzene As A Common Solvent, Arshiya Iqbal, Jamil Muhammad, Farzana Ahmad, Mohsan Nawaz, Musa Kaleem Baloch, Luqman Mohammad Jan 2022

Miscibility And Thermal Behavior Of Poly(Methyl Methacrylate) And Polystyrene Blend Using Benzene As A Common Solvent, Arshiya Iqbal, Jamil Muhammad, Farzana Ahmad, Mohsan Nawaz, Musa Kaleem Baloch, Luqman Mohammad

Turkish Journal of Chemistry

Polymer blending is one of the advanced technologies to attain polymeric material with tailored properties. In this work, the miscibility of Poly(methyl methacrylate) (PMMA) and Polystyrene (PS) blend in benzene was investigated by employing various techniques such as FTIR spectroscopy, viscosity measurement technique, light scattering techniques, DSC and TGA techniques over an extended range of concentrations, compositions, and temperatures. The results revealed that there exist hydrogen bonding and hydrodynamic interactions which led these polymers to get miscible to a large extent. The compatibility increased with the increasing PS contents or increase in temperature of the system. In addition, the thermal …

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The Relation Between Surface Acidity And Moo3:Al2o3 Ratio On The Ternary Mixed Oxide Catalysts For The Conversion Of Propan-2-Ol, Hani Zeidan, Ebru Erünal, Mustafa Esen Marti Jan 2022

The Relation Between Surface Acidity And Moo3:Al2o3 Ratio On The Ternary Mixed Oxide Catalysts For The Conversion Of Propan-2-Ol, Hani Zeidan, Ebru Erünal, Mustafa Esen Marti

Turkish Journal of Chemistry

In this study, ternary mixed oxide catalysts containing Al2O3-MoO3-MgO and Al2O3-MoO3-WO3 were prepared with a changing ratio of MoO3:Al2O3 between 0.05 and 20.00. All catalysts showed 100% selectivity towards propene during the conversion of propan-2-ol at temperatures between 220 and 400 °C. The catalysts prepared from WO3 possessed very strong acid sites, which cause higher catalytic activity than catalysts prepared from MgO. Besides, the ratio of MoO3:Al2O3 was found to be directly proportional to the conversion …

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Investigation Of Glycerol Electrooxidation Activity Of Carbon Supported Pdcu Bimetallic Electrocatalyst, Kübranur Ağtoprak, Merve Doğan Özcan, Ayşe Ni̇lgün Akin, Rami̇z Gülteki̇n Akay Jan 2022

Investigation Of Glycerol Electrooxidation Activity Of Carbon Supported Pdcu Bimetallic Electrocatalyst, Kübranur Ağtoprak, Merve Doğan Özcan, Ayşe Ni̇lgün Akin, Rami̇z Gülteki̇n Akay

Turkish Journal of Chemistry

In this study, Pd/C, Cu/C, and a series of PdCu/C bimetallic electrocatalysts were prepared by microwave-assisted modified polyol method to determine glycerol electrooxidation reaction (GOR) activities. The effect of microwave duration on catalyst structure and GOR activity was investigated on PdCu/C bimetallic catalysts. Also, a commercial Pd/C (com-Pd/C) was used to compare catalytic activities with prepared samples. Electrocatalysts were characterized by using X-ray Diffraction (XRD), Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), and Transmission Electron Microscopy (TEM) analyses. In addition, the activity and stability of electrocatalysts for GOR were examined by using cyclic voltammetry (CV) and chronoamperometry (CA). In XRD …

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Determination Of Si/Graphite Anode Composition For New Generation Li-Ion Batteries: A Case Study, İlknur Kalafat, Nesli̇han Yuca Jan 2022

Determination Of Si/Graphite Anode Composition For New Generation Li-Ion Batteries: A Case Study, İlknur Kalafat, Nesli̇han Yuca

Turkish Journal of Chemistry

Silicon with the properties of high capacity capability, moderate working potential, environmental sensitivity, and existence are the highly promising anode materials for lithium-ion batteries. Silicon anodes have disadvantageous properties and advantages like 300% volume change during lithium insertion and extraction process that can result in capacity fading and a shorter lifetime of the battery. In the literature, different optimizations of Silicon with different nanomaterials or composite materials, in different ratios, and with different binders and different procedures have been studied. The physical mixing of silicon with carbon provides a good performance by combining the high lithium storage capacity of the …

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Gold Nanoparticles/Over-Oxidized Poly-Eriochrome Black T Film Modified Electrode For Determination Of Arsenic, Mürşi̇de Ceren Afşar, Aydan Elçi̇, Zekerya Dursun Jan 2022

Gold Nanoparticles/Over-Oxidized Poly-Eriochrome Black T Film Modified Electrode For Determination Of Arsenic, Mürşi̇de Ceren Afşar, Aydan Elçi̇, Zekerya Dursun

Turkish Journal of Chemistry

A glassy carbon electrode, modified with gold nanoparticles/over-oxidized poly-eriochrome black T film, was fabricated for sensitive determination of As(III) by stripping voltammetry in an acidic medium. The electrode surface properties were characterized by cyclic voltammetry, electrochemical impedance spectroscopy, scanning electron microscope (SEM), and X-ray photoelectron spectroscopy (XPS). The electrode demonstrated a good response towards As(III), with a detection of 0.077 μM and good linearity in the range of 0.1 to 10 μM (R2 = 0.9977). For the determination of As(III), the fabricated electrode was placed in different mineral water samples, acidified with 0.75 M HCl solution, spiked with various …

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Non-Chromatographic Oligonucleotide Purification And Automated Polyethyleneglycol Synthesis, Dhananjani N. A. M. Eriyagama Jan 2022

Non-Chromatographic Oligonucleotide Purification And Automated Polyethyleneglycol Synthesis, Dhananjani N. A. M. Eriyagama

Dissertations, Master's Theses and Master's Reports

Synthetic oligodeoxynucleotides (ODN) have various applications in many areas such as, synthetic biology, chemical biology, antisense drug development, and data storage. As a result, there is a high demand for synthetic ODNs. Many advances have been made with ODN synthesis the purification still remains a bottleneck. The non-chromatographic purification method is developed to address this problem. Similarly, polyethylene glycols (PEGs) have been used in many areas including pharmaceutical applications, surface science, and nanomedicine due to its unique properties. However, monodispersed PEG synthesis is expensive with existing methods. A novel automated solid phase synthesis method is developed to obtain monodispersed PEGs. …

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Multilevel Computational Investigation Into The Dynamics And Reaction Mechanisms Of Non-Heme Iron And 2-Oxoglutarate Dependent Enzymes, Shobhit Sanjeev Chaturvedi Jan 2022

Multilevel Computational Investigation Into The Dynamics And Reaction Mechanisms Of Non-Heme Iron And 2-Oxoglutarate Dependent Enzymes, Shobhit Sanjeev Chaturvedi

Dissertations, Master's Theses and Master's Reports

Computational chemistry methods have been extensively applied to investigate biological systems. This dissertation utilizes a multilevel computational approach to explore the dynamics and reaction mechanisms of two groups of enzymes belonging to non-heme Fe(II) and 2-oxoglutarate (2OG) dependent superfamily – histone lysine demethylases from class 7 and ethylene forming enzyme (EFE). Chapter 2 uncovers the role of conformational dynamics in the substrate selectivity of histone lysine demethylases 7A and 7B. The molecular dynamics (MD) simulations of the two enzymes revealed the importance of linker flexibility and dynamics in relative orientations of the reader (PHD) and the catalytic (JmjC) domains. Chapter …

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Chromatography-Mass Spectroscopy Analysis Of Native American Pottery For Maple Syrup Residues, Alexis Wirtz Jan 2022

Chromatography-Mass Spectroscopy Analysis Of Native American Pottery For Maple Syrup Residues, Alexis Wirtz

Honors Program Theses

The research conducted regards whether or not Native Americans understood how to create maple syrup before the influence of Europeans. The analytical technique that was used is gas chromatography-mass spectrometry (GC-MS). This technique assisted in understanding what organic residues resided within the pottery and what those organic residues tell us about Native American history. An analysis of organic residues was performed on the following types of pottery: proof of concept pottery, weathered pottery (an analog of the proof of concept), and Native American pottery. The residues used in analysis were obtained through the usage of different solvent systems - Acetone: …

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Characterizing The Effects Of Solvent And Analyte Properties On Ionization Efficiency By Novel Field-Free And Field-Enabled Ionization Techniques, Kinkini Udara Jayasundara Jan 2022

Characterizing The Effects Of Solvent And Analyte Properties On Ionization Efficiency By Novel Field-Free And Field-Enabled Ionization Techniques, Kinkini Udara Jayasundara

Graduate Theses, Dissertations, and Problem Reports (ETD)

In recent years the mass spectrometry (MS) area of field and/or direct analysis has grown dramatically. As a result, field-portable and miniaturized mass spectrometers, introduced only a few years ago, are proliferating. A highly desired feature for field-portable MS, or in-field analysis, is the ability to use ionization techniques requiring very little sample preparation as well as an ability to generate the ions under ambient conditions. Recently, a new ambient ionization technique termed vibrating sharp-edge spray ionization (VSSI) has been introduced which overcomes the field-portable limitations of other spray-based methods including the requirements for auxiliary components (e.g., nebulizing gas and …

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From Evaluating The Performance Of Approximations In Density Functional Theory To A Machine Learning Design, Pedram Tavazohi Jan 2022

From Evaluating The Performance Of Approximations In Density Functional Theory To A Machine Learning Design, Pedram Tavazohi

Graduate Theses, Dissertations, and Problem Reports (ETD)

Density-functional theory (DFT) has gained popularity because of its ability to predict the properties of a large group of materials a priori. Even though DFT is exact, there are inaccuracies introduced into the theory due to the approximations in the exchange-correlation (XC) functionals. Over the 50 years of its existence, scientists have tried to improve the design of the XC functionals. The errors introduced by these functionals are not consistent across all types of solid-state materials. In this project, a high throughput framework was utilized to compare the theoretical DFT predictions with the experimental results available in the Inorganic Crystal …

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Modeling, Fabrication, And Characterization Of Rf-Based Passive Wireless Sensors Composed Of Refractory Semiconducting Ceramics For High Temperature Applications, Kavin Sivaneri Varadharajan Idhaiam Jan 2022

Modeling, Fabrication, And Characterization Of Rf-Based Passive Wireless Sensors Composed Of Refractory Semiconducting Ceramics For High Temperature Applications, Kavin Sivaneri Varadharajan Idhaiam

Graduate Theses, Dissertations, and Problem Reports (ETD)

Real-time health monitoring of high temperature systems (>500oC) in harsh environments is necessary to prevent catastrophic events caused by structural failures, varying pressure, and chemical reactions. Conventional solid-state temperature sensors such as resistance temperature detectors (RTDs) and thermocouples are restricted by their operating environments, sensor dimensions and often require external power sources for their operation. The current work presents the research and development of RF-based passive wireless sensing technology targeting high temperatures and harsh environmental conditions. Passive wireless devices are generally classified as near-field and far-field devices based on the interrogation distance. Near-field sensors are placed at …

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Determining The Effects Of Chemical Exposure On Hepatocyte Mitochondrial Networks And Cell Viability, Bethany Eaton Jan 2022

Determining The Effects Of Chemical Exposure On Hepatocyte Mitochondrial Networks And Cell Viability, Bethany Eaton

All Master's Theses

Mitochondria are cellular organelles that are becoming more recently studied. One of their main functions is the production of energy through cellular respiration, which is crucial to cell life. However, they are also associated with numerous disease states. It is hypothesized that reactive oxygen species (ROS), largely produced in mitochondria, induce oxidative stress and affect mitochondrial morphology along with cell viability. This study compares chemical exposure of menadione, an ROS producer, and phthalates (plasticizers) on two mouse hepatocyte cell lines to determine the effects they have on mitochondrial morphology and cell viability. Three experiments were performed to analyze the effects …

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