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2021

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Articles 26131 - 26160 of 27884

Full-Text Articles in Physical Sciences and Mathematics

The Smallest Solution Of An Isotropic Quadratic Form, Deborah H. Blevins Jan 2021

The Smallest Solution Of An Isotropic Quadratic Form, Deborah H. Blevins

Theses and Dissertations--Mathematics

An isotropic quadratic form f(x1,...,xn) = ∑ ni=1nj=1 fijxixj defined on a Z- lattice has a smallest solution, where the size of the solution is measured using the infinity norm (∥ ∥), the l1 norm (∥ ∥1), or the Euclidean norm (∥ ∥2). Much work has been done to find the least upper bound and greatest lower bound on the smallest solution, beginning with Cassels in the mid-1950’s. Defining F := (f11,...,f …


Weakly Supervised Learning For Multi-Image Synthesis, Muhammad Usman Rafique Jan 2021

Weakly Supervised Learning For Multi-Image Synthesis, Muhammad Usman Rafique

Theses and Dissertations--Electrical and Computer Engineering

Machine learning-based approaches have been achieving state-of-the-art results on many computer vision tasks. While deep learning and convolutional networks have been incredibly popular, these approaches come at the expense of huge amounts of labeled data required for training. Manually annotating large amounts of data, often millions of images in a single dataset, is costly and time consuming. To deal with the problem of data annotation, the research community has been exploring approaches that require less amount of labelled data.

The central problem that we consider in this research is image synthesis without any manual labeling. Image synthesis is a classic …


Glacier Peak Infographic Usability Report, Rachel Volentine Jan 2021

Glacier Peak Infographic Usability Report, Rachel Volentine

User eXperience Lab

The User-eXperience Lab at the University of Tennessee in partnership with the Cascades Volcano Observatory conducted a moderated usability study via Zoom December 7-15 2020. The moderated usability study was designed for the usability researcher to actively engage with the participant, guiding the user through a series of questions and answering questions and replying to their feedback in real time.


Multipliers And $\Mathcal{I}$-Core For Sequences, Mustafa Gülfirat, Ni̇lay Şahi̇n Bayram Jan 2021

Multipliers And $\Mathcal{I}$-Core For Sequences, Mustafa Gülfirat, Ni̇lay Şahi̇n Bayram

Turkish Journal of Mathematics

In this paper we mainly deal with $\mathcal{I}_{c}^{\left( q\right) }-$% convergence. In particular we study bounded multipliers of bounded $\mathcal{% I}_{c}^{\left( q\right) }-$convergent sequences. We also give some $\mathcal{% I}-$core results and characterize the inclusion $K-core\left \{ Ax\right \} \subseteq \mathcal{I}-core\left \{ x\right \} $ for bounded sequences $% x=\left( x_{n}\right) $.


"Who Can Help Me?'': Knowledge Infused Matching Of Support Seekers And Support Providers During Covid-19 On Reddit, Manas Gaur, Kaushik Roy, Aditya Sharma, Biplav Srivastava, Amit Sheth Jan 2021

"Who Can Help Me?'': Knowledge Infused Matching Of Support Seekers And Support Providers During Covid-19 On Reddit, Manas Gaur, Kaushik Roy, Aditya Sharma, Biplav Srivastava, Amit Sheth

Publications

During the ongoing COVID-19 crisis, subreddits on Reddit, such as r/Coronavirus saw a rapid growth in user's requests for help (support seekers - SSs) including individuals with varying professions and experiences with diverse perspectives on care (support providers - SPs). Currently, knowledgeable human moderators match an SS with a user with relevant experience, i.e, an SP on these subreddits. This unscalable process defers timely care. We present a medical knowledge-infused approach to efficient matching of SS and SPs validated by experts for the users affected by anxiety and depression, in the context of with COVID-19. After matching, each SP to …


Computational Analysis Beyond The Monomer Frontier Orbitals For Photovoltaic Donor-Polymer Candidates, Mitchell E. Lahm, Megan M. Niblock, John M. Migliore, Kendra M. Mckenzie, Hans P. Lüthi, Rollin A. King Jan 2021

Computational Analysis Beyond The Monomer Frontier Orbitals For Photovoltaic Donor-Polymer Candidates, Mitchell E. Lahm, Megan M. Niblock, John M. Migliore, Kendra M. Mckenzie, Hans P. Lüthi, Rollin A. King

Chemistry Faculty Publications

Scharber et al. proposed an efficiency model for organic photovoltaic cells based on the orbital energies of the monomers of the donor- and acceptor- polymers [Advanced Materials 18 (2006) 789–794]. We report theoretical extensions of this approach. First, the frontier-orbital energies and electronic spectra of n-length oligomers (n = 1 − 5) of 3-butylthiophene have been determined. The results show reasonable convergence with respect to system size at the point of a trimer with alkyl end caps. The HOMO-LUMO gap well matches computed excitation energies. Second, the structures and electronic spectra of dimers formed by three different monomers, with various …


Bias Of Rank Correlation Under A Mixture Model, Russell Land Jan 2021

Bias Of Rank Correlation Under A Mixture Model, Russell Land

Electronic Theses and Dissertations

This thesis project will analyze the bias in mixture models when contaminated data is present. Specifically, we will analyze the relationship between the bias and the mixing proportion, p, for the rank correlation methods Spearman’s Rho and Kendall’s Tau. We will first look at the history of the two non-parametric rank correlation methods and the sample and population definitions will be introduced. Copulas will be introduced to show a few ways we can define these correlation methods. After that, mixture models will be defined and the main theorem will be stated and proved. As an example, we will apply this …


Comparison Of Clinically Approved Molecules On Sars-Cov-2 Drug Target Proteins: A Molecular Docking Study, Hasan Çubuk, Mehmet Özbi̇l Jan 2021

Comparison Of Clinically Approved Molecules On Sars-Cov-2 Drug Target Proteins: A Molecular Docking Study, Hasan Çubuk, Mehmet Özbi̇l

Turkish Journal of Chemistry

The new type of coronavirus, SARS-CoV-2 has affected more than 22.6 million people worldwide. Since the first day the virus was spotted in Wuhan, China, numerous drug design studies have been conducted all over the globe. Most of these studies target the receptor-binding domain of spike protein of SARS-CoV-2, which is known to bind to the human ACE2 receptor and SARS-CoV-2 main protease, vital for the virus' replication. However, there might be a third target, human furin protease, which cleaves the virus' S1-S2 domains playing an active role in its entry into the host cell. In this study, we docked …


Novel Nonperipheral Octa-3-Hydroxypropylthio Substituted Metallo-Phthalocyanines: Synthesis, Characterization, And Investigation Of Their Electrochemical, Photochemical And Computational Properties, Ni̇lgün Kabay, Yasemi̇n Bayğu, Meti̇n Ak, İzzet Kara, Esra Nur Kaya, Mahmut Durmuş, Yaşar Gök Jan 2021

Novel Nonperipheral Octa-3-Hydroxypropylthio Substituted Metallo-Phthalocyanines: Synthesis, Characterization, And Investigation Of Their Electrochemical, Photochemical And Computational Properties, Ni̇lgün Kabay, Yasemi̇n Bayğu, Meti̇n Ak, İzzet Kara, Esra Nur Kaya, Mahmut Durmuş, Yaşar Gök

Turkish Journal of Chemistry

The current study describes the synthesis, electrochemical, computational, and photochemical properties of octa (3-hydroxypropylthio) substituted cobalt (II) (4), copper (II) (5), nickel (II) (6) and zinc(II) (7) phthalocyanine derivatives. These novel compounds were characterized by elemental analysis, 1H, 13C NMR, FT-IR, UV-Vis, and MS. The redox behaviors of these metallo-phthalocyanines were investigated by the cyclic voltammetric method. The optimized molecular structure and gauge-including atomic orbital (GIAO) 1H and 13C NMR chemical shift values of these phthalocyanines in the ground state had been calculated by using B3LYP/6-31G(d,p) basis set. The outcomes of the optimized molecular structure were given and compared with …


Fabrication Of Silane-Modified Magnetic Nano Sorbent For Enhanced Ultrasonic Wave Driven Removal Of Methylene Blue From Aqueous Media: Isotherms, Kinetics, And Thermodynamic Mechanistic Studies, Abdullah ., Esra Alveroğlu Durucu, Aamna Balouch, Ali Muhammad Mahar Jan 2021

Fabrication Of Silane-Modified Magnetic Nano Sorbent For Enhanced Ultrasonic Wave Driven Removal Of Methylene Blue From Aqueous Media: Isotherms, Kinetics, And Thermodynamic Mechanistic Studies, Abdullah ., Esra Alveroğlu Durucu, Aamna Balouch, Ali Muhammad Mahar

Turkish Journal of Chemistry

In this study, we report a simple and economic one-pot synthesis of magnetite (Fe3O4) nanostructure and its modification with tetraethyl orthosilicate by coprecipitation method. The synthesized (Fe3O4@SiO2) nano sorbent was applied for enhanced adsorptive removal of methylene blue by ultrasonic wave driven batch experiments. After successful synthesis, the nanostructure was characterized for their physical structure by FT-IR, VSM, TEM, and XRD. For the maximum adsorptive performance of nano sorbent, various parameters were optimized, such as dose, pH, time, concentration, and temperature. The adsorption mechanism was best fitted by Langmuir isotherm with a maximum capacity of 148.69 mg/g, while kinetics best …


Cytotoxic And Apoptotic Potential Of Some Coumarin And 2-Amino-3-Carbonitrile Selenophene Derivatives In Prostate Cancer, Meti̇n Yildirim, Mehmet Erşatir, Badel Arslan, Eli̇fe Sultan Gi̇ray Jan 2021

Cytotoxic And Apoptotic Potential Of Some Coumarin And 2-Amino-3-Carbonitrile Selenophene Derivatives In Prostate Cancer, Meti̇n Yildirim, Mehmet Erşatir, Badel Arslan, Eli̇fe Sultan Gi̇ray

Turkish Journal of Chemistry

3-acetyl coumarin derivatives (1a-d) are formed as a result of condensation of salicylaldehyde derivatives and ethyl acetoacetate and were converted into coumarin-selenophene hybrid compounds (2a-d) in the basic medium by modified Gewald reaction in the presence of malononitrile and selenium. Products are characterized by nuclear magnetic resonance (NMR). The prepared compounds are screened for their anticancer activity against DU-145 cell line. In addition, selected target compounds are evaluated for apoptosis and oxidative stress on DU-145 (prostate carcinoma) cell lines.


Size-Controllable Carbon Spheres Doped Ni (Ii) For Enhancing The Catalytic Oxidation Of Methanol, Yifen Hu, Pengyu Gao, Zhen Xu, Chuan Zhang, Lizhen Huang, Yunting Hu, Yarui An, Yingying Gu Jan 2021

Size-Controllable Carbon Spheres Doped Ni (Ii) For Enhancing The Catalytic Oxidation Of Methanol, Yifen Hu, Pengyu Gao, Zhen Xu, Chuan Zhang, Lizhen Huang, Yunting Hu, Yarui An, Yingying Gu

Turkish Journal of Chemistry

Ni(II)/CSs were prepared using a simple two-step hydrothermal method. The morphology and composition of the catalysts were studied with scanning electron microscope, transmission electron microscope, and X-ray diffraction. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy showed that the surface of the prepared carbon spheres was rich in hydroxyl groups, which was beneficial to remove CO intermediates, and therefore, improving the catalytic efficiency and the antipoisoning ability of the catalysts. The results of cyclic voltammetry and chronoamperometry showed that the electrocatalytic activity and stability of Ni(II)/CSs were higher than that of unloaded NiAc under alkaline environment. When the nickel content …


4,4'-Trimethylenedipiperidine As A Nitrogen Heterocycle Solvent And/Or Catalyst: Liquid Phase Tandem Knoevenagel-Michael Condensation, Lia Zaharani, Nader Ghaffari Khaligh, Hayede Gorjian, Mohd Rafie Johan Jan 2021

4,4'-Trimethylenedipiperidine As A Nitrogen Heterocycle Solvent And/Or Catalyst: Liquid Phase Tandem Knoevenagel-Michael Condensation, Lia Zaharani, Nader Ghaffari Khaligh, Hayede Gorjian, Mohd Rafie Johan

Turkish Journal of Chemistry

Liquid phase tandem Knoevenagel-Michael condensation of various aromatic and heteroaromatic aldehydes with barbituric acid or 2-thiobarbituric acid and malononitrile was studied in a one-pot three-component reaction. For the first time, TMDP was employed as a safe and efficient solvent and/or catalyst in the liquid and aqueous ethanol medium, respectively, for the practical and eco-friendly Knoevenagel-Michael condensation. The reactions were carried out by using greener procedures, including a) the use of TMDP as an N-heterocycle organocatalyst in a green medium including water and ethanol (1:1 v/v) at reflux temperature, and b) the use of TMDP as a dual solvent-catalyst at 65 …


Treatment Of Industrial Contaminants With Zero-Valent Iron- And Zero-Valent Aluminiumactivatedpersulfate: A Case Study With 3,5-Dichlorophenol And 2,4-Dichloroaniline, Olga Koba Ucun, Bahareh Montazeri̇, İdi̇l Arslan Alaton, Tuğba Ölmez Hanci Jan 2021

Treatment Of Industrial Contaminants With Zero-Valent Iron- And Zero-Valent Aluminiumactivatedpersulfate: A Case Study With 3,5-Dichlorophenol And 2,4-Dichloroaniline, Olga Koba Ucun, Bahareh Montazeri̇, İdi̇l Arslan Alaton, Tuğba Ölmez Hanci

Turkish Journal of Chemistry

Zero-valent iron (ZVI)- and zero-valent aluminium (ZVA)-activated persulfate (PS) oxidation procedure was applied to remove the industrial pollutants 3,5-dichlorophenol (3,5-DCP; 12.27 μM) and 2,4-dichloroaniline (2,4-DCA; 12.34 μM) from aqueous solutions. The effects of PS concentration and pH were investigated to optimize heterogeneous treatment systems. Negligible removals were obtained for both pollutants by individual applications of nanoparticles (1 g/L) and PS (1.00 mM). PS activation with ZVI resulted in 59% (1.00 mM PS; 1 g/L ZVI; pH 5.0; 120 min) and 100% (0.75 mM PS; 1 g/L ZVI; pH 5.0; 80 min) 3,5-DCP and 2,4-DCA removals, respectively. The ZVA/PS treatment system …


Removal Of Cd(Ii), Cu(Ii), And Pb(Ii) By Adsorption Onto Natural Clay: A Kinetic Andthermodynamic Study, Brahim Abbou, Imane Lebkiri, Hanae Ouaddari, Lamya Kadiri, Abdelkarim Ouass, Amar Habssaoui, Ahmed Lebkiri, El Housseine Rifi Jan 2021

Removal Of Cd(Ii), Cu(Ii), And Pb(Ii) By Adsorption Onto Natural Clay: A Kinetic Andthermodynamic Study, Brahim Abbou, Imane Lebkiri, Hanae Ouaddari, Lamya Kadiri, Abdelkarim Ouass, Amar Habssaoui, Ahmed Lebkiri, El Housseine Rifi

Turkish Journal of Chemistry

In this work, we study the elimination of three bivalent metal ions (Cd$^{2+}$, Cu$^{2+}$, and Pb$^{2+}$) by adsorption onto natural illitic clay (AM) collected from Marrakech region in Morocco. The characterization of the adsorbent was carried out by X-ray fluorescence, Fourier transform infrared spectroscopy and X-ray diffraction. The influence of physicochemical parameters on the clay adsorption capacity for ions Cd$^{2+}$, Cu$^{2+}$, and Pb$^{2+}$, namely the adsorbent dose, the contact time, the initial pH imposed on the aqueous solution, the initial concentration of the metal solution and the temperature, was studied. The adsorption process is evaluated by different kinetic models such …


Comparative Study On The Effect Of Precursors On The Morphology And Electronicproperties Of Cds Nanoparticles, Kevin I. Y. Ketchemen, Sixberth Mlowe, Linda D. Nyamen, Peter T. Ndifon, Neerish Revaprasadu Jan 2021

Comparative Study On The Effect Of Precursors On The Morphology And Electronicproperties Of Cds Nanoparticles, Kevin I. Y. Ketchemen, Sixberth Mlowe, Linda D. Nyamen, Peter T. Ndifon, Neerish Revaprasadu

Turkish Journal of Chemistry

Cadmium dithiocarbamate and cadmium ethyl xanthate complexes were synthesized and characterized by microanalysis, Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric analyses. The complexes were employed as molecular precursors for the fabrication of CdS nanoparticles in hexadecylamine (HDA) and oleylamine (OLA) at a temperature of 250 °C. Spherical and oval shaped particles with sizes ranging from 9.93 ± 1.89 to 16.74 ± 2.78 nm were obtained in OLA while spherical, oval and rod shaped particles with sizes ranging from 9.40 ± 1.65 to 29.90 ± 5.32 nm were obtained in HDA. Optical properties of the nanoparticles showed blue shifts as compared …


The Effect Of H$_{2}$O On The Sulfation Of Havelock Limestone Under Oxy-Fuel Conditions In Athermogravimetric Analyser, Murat Varol, Edward John Anthony, Arturo Macchi Jan 2021

The Effect Of H$_{2}$O On The Sulfation Of Havelock Limestone Under Oxy-Fuel Conditions In Athermogravimetric Analyser, Murat Varol, Edward John Anthony, Arturo Macchi

Turkish Journal of Chemistry

A gas mixture representing oxy-fuel combustion conditions was employed in a thermogravimetric analyser to determine the effect of water vapor and SO$_{2}$ concentration on limestone sulfation kinetics over the temperature range of 800 to 920 °C. Here, experiments used small samples of particles (4 mg), with small particle sizes (d$_{p}$ < 38 μm) and large gas flow rates (120 mL/min@ NTP) in order to minimize mass transfer interferences. The gas mixture contained 5000 ppm$_{v}$ SO$_{2}$, 2% O$_{2}$, and the H$_{2}$O content was changed from 0% to 25% with the balance CO$_{2}$. When water vapor was added to the gas mixture at lower temperatures (800-870 °C), the limestone SO$_{2}$ capture efficiency increased. However, as the temperature became higher, the enhancement in total conversion values decreased. As expected, Havelock limestone at higher temperatures (890 °C, 920 °C, and 950 °C) experienced indirect sulfation and reacted at a faster rate than for lower temperatures (800-870 °C) for direct sulfation over the first five minutes of reaction time. However, the total conversion of Havelock limestone for direct sulfation was generally greater than for indirect sulfation.


Spectroscopic Investigation Of Defect-State Emission In Cdse Quantum Dots, Gülhan Güleroğlu, Caner Ünlü Jan 2021

Spectroscopic Investigation Of Defect-State Emission In Cdse Quantum Dots, Gülhan Güleroğlu, Caner Ünlü

Turkish Journal of Chemistry

CdSe quantum dots are the most studied Cd-based quantum dots with their high quantum yield, high photostability, narrow emission band, and easy synthesis procedure. They are frequently used to develop light emitting diode (LED) due to their unique photo¬physical properties; however, their narrow emission band causes a challenge to design white LEDs because white light emission requires emission in multiple wavelengths with broad emission bands. Here in this study, we developed CdSe quantum dots with a narrow band-edge emission band and broad defect-state emission band through a modified two-phase synthesis method. Our results revealed that defect-state emission is directly linked …


Tin-Sulfur Based Catalysts For Acetylene Hydrochlorination, Yibo Wu, Fuxiang Li, Xiaoqiang Luo, Gang Tian, Yunxiao Feng, Yongjun Han, Li Wang, Songmao Chu, Yunli Cao, Kesheng Cao, Xiaoming Hu, Xuejun Shi, Songtian Li, Guoxv He, Qingbin Li Jan 2021

Tin-Sulfur Based Catalysts For Acetylene Hydrochlorination, Yibo Wu, Fuxiang Li, Xiaoqiang Luo, Gang Tian, Yunxiao Feng, Yongjun Han, Li Wang, Songmao Chu, Yunli Cao, Kesheng Cao, Xiaoming Hu, Xuejun Shi, Songtian Li, Guoxv He, Qingbin Li

Turkish Journal of Chemistry

In the present work, tin-sulfur based catalysts were prepared using Na2SO3 and (CH3SO3)2Sn and were tested in acetylene hydrochlorination. Based on the analysis of experiments results, the acetylene conversion of (CH3SO3)2Sn/S@AC is still over 90% after a 50 h reaction, at the reaction conditions of T = 200 oC, VHCl/VC2H2 = 1.1:1.0 and C2H2-GSHV = 15 h-1. According to the results of X-ray photoelectron spectroscopy (XPS), HCl adsorption experiments, and acetylene temperature programmed desorption (C2H2-TPD), it is reasonable to conclude that the interaction between Sn and S not only can retard the oxidation of Sn2+ in catalysts but also strengthen …


Synthesis, Spectroscopic, Thermal, Crystal Structure Properties And Characterization Of New Hofmann-Type-Like Clathrates With 4-Aminopyridine And Water, Zeki̇ Kartal, Onur Şahi̇n Jan 2021

Synthesis, Spectroscopic, Thermal, Crystal Structure Properties And Characterization Of New Hofmann-Type-Like Clathrates With 4-Aminopyridine And Water, Zeki̇ Kartal, Onur Şahi̇n

Turkish Journal of Chemistry

In this study, synthesis of two new heteronuclear tetracyanonickelate(II) clathrates based on 4-aminopyridine (4AP) and guest water (H2O) molecule and investigation of their structural properties were reported. These clathrates were characterized by using vibration spectroscopy, elemental, thermal analysis and single crystal X-ray diffraction (SC-XRD) techniques. Examining the elemental and spectral data of these clathrates, it was observed that the formulas [Zn(II)(4AP)2Ni(μ-CN)2 (CN)2]·6H2O and [Cu(II)(4AP)4Ni(μ- CN)2 (CN)2]·H2O were defined their structures. General information about the structural properties of these clathrates in single crystal form has been obtained by considering the changes in the characteristic peaks of the cyanide group and the …


The Protective Role Of Melatonin Under Heavy Metal-Induced Stress In Melissa Officinalis L., Elvisa Hodzic, Semira Galijasevic, Milica Balaban, Sebila Rekanovic, Halid Makic, Biljana Kukavica, Dijana Mihajlovic Jan 2021

The Protective Role Of Melatonin Under Heavy Metal-Induced Stress In Melissa Officinalis L., Elvisa Hodzic, Semira Galijasevic, Milica Balaban, Sebila Rekanovic, Halid Makic, Biljana Kukavica, Dijana Mihajlovic

Turkish Journal of Chemistry

Heavy metals, due to their inability to degrade, pose a serious environmental and nutritional problem. The accumulation of essential and non-essential heavy metals in living organisms reduces normal growth and development, resulting in acute poisoning, disease and even death of organisms. Melatonin is a very important multifunctional molecule in protecting plants from oxidative stress due to its ability to directly neutralize reactive oxygen species (ROS). Also, melatonin has a chelating property, which may contribute in reducing metal-induced toxicity. In this paper, the protective role of melatonin in counteracting metal-induced free radical generation was highlighted. Using the HPLC-FLD technique melatonin was …


Thermal Stresses In Sofc Stacks: The Role Of Mismatch Among Thermalconductivity Of Adjacent Components, Özgür Aydin, Go Matsumoto, Yusuke Shiratori Jan 2021

Thermal Stresses In Sofc Stacks: The Role Of Mismatch Among Thermalconductivity Of Adjacent Components, Özgür Aydin, Go Matsumoto, Yusuke Shiratori

Turkish Journal of Chemistry

Generating power from renewable biogas in solid oxide fuel cells (SOFCs) is an environment-friendly, efficient, and promising energy conversion process. Biogas can be used in SOFCs via a reforming process for which dry reforming is more suitable as the reforming agent exists in the biogas mixture. Biogas can be directly reformed to H2 -rich fuel stream in the anode chamber of a SOFC by the heat released during power generation. Exploiting the heat and water produced in the SOFC for internal reforming of biogas makes the energy conversion process very efficient; however, various challenges are reported. Thus, indirect internal reforming …


Synthesis Of Hydroxy Benzoin/Benzil Analogs And Investigation Of Their Antioxidant,Antimicrobial, Enzyme Inhibition, And Cytotoxic Activities, Nuretti̇n Yayli, Gözde Kiliç, Gonca Çeli̇k, Nuran Kahri̇man, Şeyda Kanbolat, Ari̇f Bozdeveci̇, Şengül Alpay Karaoğlu, Rezzan Ali̇yazicioğlu, Hasan Erdi̇nç Selli̇tepe, İnci̇ Seli̇n Doğan, Ali̇ Aydin Jan 2021

Synthesis Of Hydroxy Benzoin/Benzil Analogs And Investigation Of Their Antioxidant,Antimicrobial, Enzyme Inhibition, And Cytotoxic Activities, Nuretti̇n Yayli, Gözde Kiliç, Gonca Çeli̇k, Nuran Kahri̇man, Şeyda Kanbolat, Ari̇f Bozdeveci̇, Şengül Alpay Karaoğlu, Rezzan Ali̇yazicioğlu, Hasan Erdi̇nç Selli̇tepe, İnci̇ Seli̇n Doğan, Ali̇ Aydin

Turkish Journal of Chemistry

In this study, hydroxy benzoin (1-7), benzil (8-14), and benzoin/benzil-O-β-D-glucosides (15-25) were synthesized to investigate their biological activities. An efficient method for synthesizing hydroxy benzoin compounds (1-7) was prepared from four different benzaldehydes using an ultrasonic bath. Then, antioxidant (FRAP, CUPRAC, and DPPH), antimicrobial (3 Gram (-), 4/6 Gram (+), one tuberculosis and one fungus), and enzyme inhibition (acetylcholinesterase, butyrylcholine esterase, tyrosinase, α-amylase, and α- glucosidase) for the all synthesized compounds (1-25) were evaluated. And also, four most active compounds (4, 12, 18a+b, and 25) from each group were evaluated to the human cervical cancer cell line (HeLa) and anticancer …


Synthesis And Antioxidant Activities Of New Nickel(Ii) Complexes Derived From 4-Benzy¬Loxysalicylidene-S-Methyl/Propyl Thiosemicarbazones, Songül Eğlence Bakir Jan 2021

Synthesis And Antioxidant Activities Of New Nickel(Ii) Complexes Derived From 4-Benzy¬Loxysalicylidene-S-Methyl/Propyl Thiosemicarbazones, Songül Eğlence Bakir

Turkish Journal of Chemistry

Six nickel(II) complexes of the N2O2 chelating thiosemicarbazones were synthesized using N1-4-benzyloxysalicylidene-S-methyl/propyl thiosemicarbazone and methoxy-substitute-salicylaldehydes in the presence of Ni(II) ion by template reaction. The structures of thiosemicarbazones and nickel(II) complexes were characterized by elemental analysis, UV-Vis, IR, and 1H-NMR spec¬troscopies. The structure of the N1-4-benzyloxysalicylidene-S-propyl thiosemicarbazone (2) was determined by X-ray single-crystal diffraction method. The total antioxidant capacities of synthesized compounds were evaluated by using cupric reducing antioxidant capacity (CUPRAC) method. The thiosemicarbazones exhibited more potent antioxidant capacity than Ni(II) complexes. Trolox equiv¬alent antioxidant capacity (TEAC) of 1c was found highest in tested nickel(II) complexes. In addition, antioxidant activities …


Synthesis, Spectroscopic, Thermal, Crystal Structure Properties, And Characterization Of New Hofmann-Td-Type Complexes With 3-Aminopyridine, Zeki̇ Kartal, Onur Şahi̇n Jan 2021

Synthesis, Spectroscopic, Thermal, Crystal Structure Properties, And Characterization Of New Hofmann-Td-Type Complexes With 3-Aminopyridine, Zeki̇ Kartal, Onur Şahi̇n

Turkish Journal of Chemistry

In this study, synthesis of two new tetracyanocadmate(II) and tetracyanozincate(II) complexes based on 3-aminopyridine (3AP) and investigation of their structural properties were reported. These complexes were characterized by using vibration spectroscopy, elemental, thermal analysis and single crystal X-ray diffraction (SC-XRD) techniques. Investigation of the elemental, spectral and single crystal data of these complexes showed that the formulas [Cd(3AP)2Zn(μ4-CN)4]n (1) and [Cd(3AP) 2Cd(μ4-CN)4]n (2) fully explained their crystal structure. General information about the structural and chemical properties of these complexes obtained in single crystal form was obtained by observing the changes in the characteristic peaks of the 3AP with the [Zn(μ4-CN)4]2- …


Phenolic Compounds, Essential Oil Composition, And Antioxidant Activity Of Angelica Pur-Purascens (Avé-Lall.) Gill, Semra Alkan Türkuçar, Ayça Aktaş Karaçeli̇k, Mustafa Karaköse Jan 2021

Phenolic Compounds, Essential Oil Composition, And Antioxidant Activity Of Angelica Pur-Purascens (Avé-Lall.) Gill, Semra Alkan Türkuçar, Ayça Aktaş Karaçeli̇k, Mustafa Karaköse

Turkish Journal of Chemistry

In this study, methanol extracts (MEs) and essential oil (EO) of Angelica purpurascens (Avé-Lall.) Gill obtained from different parts (root, stem, leaf, and seed) were evaluated in terms of antioxidant activity, total phenolics, compositions of phenolic compound, and essential oil with the methods of 2,2-azino-bis(3ethylbenzo-thiazoline-6-sulfonic acid (ABTS•+), 2,2-diphenyl-1-picrylhydrazil (DPPH•) radical scavenging activities, and ferric reducing/antioxidant power (FRAP), the Folin?Ciocalteu, liquid chromatography- tandem mass spectrometry (LC-MS/MS), and gas chromatography-mass spectrometry (GC-MS), respectively. The root extract of A. Purpurascens exhibited the highest ABTS•+, DPPH•, and FRAP activities (IC50: 0.05 ± 0.0001 mg/mL, IC50: 0.06 ± 0.002 mg/mL, 821.04 ± 15.96 μM TEAC …


Synthesis Of Ni/Al2o3 Catalysts Via Alkaline Polyol Method And Hydrazine Reduction Method For The Partial Oxidation Of Methane, Ezgi̇ Bayrakdar Ateş, Tuba Gürkaynak Altinçeki̇ç, Mehmet Ali̇ Faruk Öksüzömer Jan 2021

Synthesis Of Ni/Al2o3 Catalysts Via Alkaline Polyol Method And Hydrazine Reduction Method For The Partial Oxidation Of Methane, Ezgi̇ Bayrakdar Ateş, Tuba Gürkaynak Altinçeki̇ç, Mehmet Ali̇ Faruk Öksüzömer

Turkish Journal of Chemistry

Nickel catalysts supported on γ-Al2O3 were synthesized in the presence of polyvinylpyrrolidone (PVP) using both alkaline polyol method and hydrazine reduction method while fixing the weight ratio of [(PVP)]/[Ni(CH3COO)2·4H2O] at 2. The effects of hydrazine [N2H5 OH]/[Ni] and [NaOH]/[Ni] molar ratios on the structural properties of the catalysts were characterized by transmission electron microscopy (HRTEM) and by X-ray diffraction (XRD). The average of monodispersed Ni nanoparticles ranged between 8.0 and 13.0 nm. The catalytic tests were performed for the partial oxidation of methane in the temperature range of 600-800 °C under a flow rate of 157,500 L kg-1 hr-1 with …


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 …


Detection Of Bacteria Using Antimicrobial Polymer Derived Via Ring-Opening Metathesis (Romp) Pathway, N Ceren Süer, Tüli̇n Arasoğlu, Hüsnü Cankurtaran, Mustafa Okutan, Markus Gallei, Tarik Eren Jan 2021

Detection Of Bacteria Using Antimicrobial Polymer Derived Via Ring-Opening Metathesis (Romp) Pathway, N Ceren Süer, Tüli̇n Arasoğlu, Hüsnü Cankurtaran, Mustafa Okutan, Markus Gallei, Tarik Eren

Turkish Journal of Chemistry

There is growing interest in the detection of bacteria in consumables, for example, in the food and water sectors. In this study, the aim was to produce a polymer-based bacteria biosensor via ROMP (ring opening metathesis polymerization). In the first part of the study, block and random copolymers were synthesized, and their biocidal activities were tested on the glass surface. Interdigitated electrode arrays coated with the polymers possessing the highest activity were used to screen the affinity towards different bacterial strains by monitoring impedance variations in real-time. The polymer-coated electrode could detect gram-positive and gram-negative bacteria strains at a concentration …


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, …