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Full-Text Articles in Physical Sciences and Mathematics

Design, Synthesis, And Antitumor Evaluation Of Novel Methylene Moiety-Tethered Tetrahydroquinoline Derivatives, Esaam Hamied Ahmed Hanashalshahaby, Canan Ünaleroğlu, Ayşe Ak Can, Alp Özgün, Bora Gari̇pcan Jan 2019

Design, Synthesis, And Antitumor Evaluation Of Novel Methylene Moiety-Tethered Tetrahydroquinoline Derivatives, Esaam Hamied Ahmed Hanashalshahaby, Canan Ünaleroğlu, Ayşe Ak Can, Alp Özgün, Bora Gari̇pcan

Turkish Journal of Chemistry

Novel methylene-tethered tetrahydroquinolines (THQs) and cyclopenta[$b$]pyridines were synthesized by one-pot multicomponent reactions of Mannich bases, enolizable ketones, and NH$_{4}$OAc in water by an environmentally friendly K-10 montmorillonite clay-catalyzed reaction. The cytotoxic activities of 1-(2-methyl-8-methylene-5,6,7,8-tetrahydroquinolin-3-yl)ethanone (9a), ethyl 2-methyl-8-methylene-5,6,7,8-tetrahydroquinoline-3 carboxylate (9b), and 1-(2-methyl-7-methylene-6,7-dihydro-5$H$-cyclopenta[$b$]pyridin-3-yl)ethanone (11a) were tested against rat glioblastoma (C6), human breast cancer (MCF-7), prostate cancer (PC3), neuroblastoma (SH-SY5Y), and mouse fibroblast (L929) cell lines in a concentration-dependent (50-300 μM) and time-dependent (24-72 h) manner and expressed as IC$_{50\, }$values. The results showed that compound 9a induced the lowest IC$_{50\, }$values in all cell lines ranging from 111 ± 1.1 μM to …


Stability Improvement By Crosslinking Of Previously Immobilized Glucose Oxidase On Carbon Nanotube-Based Bioanode, Tahsi̇n Bahar Jan 2019

Stability Improvement By Crosslinking Of Previously Immobilized Glucose Oxidase On Carbon Nanotube-Based Bioanode, Tahsi̇n Bahar

Turkish Journal of Chemistry

Bioanode stability with glucose oxidase was enhanced significantly by covalent crosslinking without substantial enzymatic activity and affinity loss. Initially, glucose oxidase was immobilized by aldehyde groups on the electrode that was developed using ferrocenecarboxaldehyde, polyethyleneimine, multiwall carbon nanotubes, and carbon cloth for biofuel cell applications. The glucose oxidase half-life was extended by more than 4 times, from 27.2 to 124.7 h, after the electrode was crosslinked. Enzymatic kinetic parameters were determined for the crosslinked enzyme and they were compared to the noncrosslinked immobilized enzyme parameters on the electrode. The apparent substrate affinity of the crosslinked enzyme electrode was decreased (i.e. …


Step-By-Step Optimization Of The Hilic Method For Simultaneous Determination Of Abacavir, Lamivudine, And Zidovudine From Dosage Form, Cem Erkmen, Mehmet Gümüştaş, Si̇bel Ayşil Özkan, Bengi̇ Uslu Jan 2019

Step-By-Step Optimization Of The Hilic Method For Simultaneous Determination Of Abacavir, Lamivudine, And Zidovudine From Dosage Form, Cem Erkmen, Mehmet Gümüştaş, Si̇bel Ayşil Özkan, Bengi̇ Uslu

Turkish Journal of Chemistry

Combined therapy for HIV treatment shows superior efficacy in comparison to single therapy. Furthermore, the separation and determination of the combined dosage forms hold a significant place in the pharmaceutical industry. Not only reverse phase high-performance liquid chromatography (HPLC) but also hydrophilic interaction liquid chromatography (HILIC) can be used for these purposes. Contrary to conventional RP systems, HILIC may be an alternative for the analysis of polar substances. The aim of this study was the step-by-step development of a simple, rapid, and reliable method for the simultaneous determination of antiviral compounds from their marketed formulation (Trizivir). In order to achieve …


Synthesis Of Hofmann-Type Zn(H$_2$O)$_2$Ni(Cn)$_4$.Ng (G = Water And 1,4-Dioxane) Clathrates And The Determination Of Their Structural Properties By Various Spectroscopic Methods, Zeki̇ Kartal, Onur Şahi̇n, Abdülkeri̇m Yavuz Jan 2019

Synthesis Of Hofmann-Type Zn(H$_2$O)$_2$Ni(Cn)$_4$.Ng (G = Water And 1,4-Dioxane) Clathrates And The Determination Of Their Structural Properties By Various Spectroscopic Methods, Zeki̇ Kartal, Onur Şahi̇n, Abdülkeri̇m Yavuz

Turkish Journal of Chemistry

Two new 2-dimensional cyanide-bridged coordination polymers [Zn(H$_{2}$O)$_{2}$Ni(CN)$_{4}$ 6(H$_{2}$O) and Zn(H$_{2}$O)$_{2}$ Ni(CN)$_{4}$ 3(C$_{4}$H$_{8}$O$_{2})$], which were similar to Hofmann-type clathrates, were synthesized based on [Ni(CN)$_{4}$]$^{2-}$ and Zn$^{2+}$ as building blocks. These substances were synthesized as compounds in crystalline form. Thes tructures of the crystalline compounds were characterized via their spectral analyses. General information about the structures of the newly obtained Hofmann-type clathrates was obtained from their vibration spectra by considering significant changes in the vibration peaks of the cyanide group, water ligand molecule, and guest molecules (water and 1,4-dioxane). The thermal behavior of the Hofmann-type clathrates was investigated in the range of …


One-Pot Synthesis Of Quinazolin-4(3$H$)-Ones And 2,3-Dihydroquinazolin-4(1$H$)-Ones Utilizing $N$-(2-Aminobenzoyl)Benzotriazoles, İlbi̇lge Merve Şenol, İlhami̇ Çeli̇k, İlker Avan Jan 2019

One-Pot Synthesis Of Quinazolin-4(3$H$)-Ones And 2,3-Dihydroquinazolin-4(1$H$)-Ones Utilizing $N$-(2-Aminobenzoyl)Benzotriazoles, İlbi̇lge Merve Şenol, İlhami̇ Çeli̇k, İlker Avan

Turkish Journal of Chemistry

A convenient and efficient method has emerged for the one-pot synthesis of substituted quinazolin-4(3$H)$-ones and nonaromatic alkaloids. 2-Substituted quinazolin-4(3H)-ones, 2,3-disubstituted quinazolin-4(3$H)$-ones, and 2,3-dihydroquinazolin-4(1$H)$-ones were obtained at yields of 46% to 95% by a one-pot reaction of $N$-(2-aminobenzoyl) benzotriazoles with amines and orthoesters or aldehydes under catalyst-free conditions.


Synthesis And Catalytic Activity Of Ionic Palladium \Textit{N}-Heterocyclic Carbene Complexes, Sedat Yaşar, Mi̇tat Akkoç, Namik Özdemi̇r, İsmai̇l Özdemi̇r Jan 2019

Synthesis And Catalytic Activity Of Ionic Palladium \Textit{N}-Heterocyclic Carbene Complexes, Sedat Yaşar, Mi̇tat Akkoç, Namik Özdemi̇r, İsmai̇l Özdemi̇r

Turkish Journal of Chemistry

The synthesis of 3 benzimidazole-based ionic Pd(II)-NHC complexes (NHC:$N$-heterocyclic carbene) is presented. The structures of the complexes are as follows: [NHC-PdBr$_{3}$]$^{-}$[NHC]$^{+}$. The ionic palladium(II)-NHC complexes were synthesized in high yields and were fully characterized by nuclear magnetic resonance spectroscopy, X-ray diffraction, LC-MS/MS, and elemental analysis. These complexes have been identified as active catalysts in Suzuki-Miyaura reactions in a solution of 2-propanol and water at room temperature for different aryl bromides.


Dispersive Liquid-Liquid Microextraction Of Parabens From Pharmaceuticals And Personal Care Products Prior To Their Determination Using Hplc-Dad, Malek Hassan, Usama Alshana, Nusret Ertaş Jan 2019

Dispersive Liquid-Liquid Microextraction Of Parabens From Pharmaceuticals And Personal Care Products Prior To Their Determination Using Hplc-Dad, Malek Hassan, Usama Alshana, Nusret Ertaş

Turkish Journal of Chemistry

Dispersive liquid--liquid microextraction followed by a back-extraction step was combined with HPLC-DAD for the determination of four parabens (i.e. methyl-, ethyl-, propyl-, and butylparaben). Optimum extraction conditions were found as follows: 225 $\mu $L of chloroform, 0.75 mL of ethanol, 7.5 mL of aqueous solution and within an extraction time of 15 s. Back-extraction into 100 $\mu $L of 50 mM sodium hydroxide solution within 20 s resulted in a reversed-phase HPLC-compatible extract. The analytes were separated at 20 $^{\circ}$C using methanol (A) and water (B), 40:60 (A:B, v/v) as the mobile phase, a flow rate of 1.0 mL min$^{-1}$ …


Synthesis, Characterization, And Investigation Of Singlet Oxygen, Dna Interaction, And Topoisomerase I Inhibition Properties Of Novel Zinc(Ii) Phthalocyanine, Ümi̇t Demi̇rbaş Jan 2019

Synthesis, Characterization, And Investigation Of Singlet Oxygen, Dna Interaction, And Topoisomerase I Inhibition Properties Of Novel Zinc(Ii) Phthalocyanine, Ümi̇t Demi̇rbaş

Turkish Journal of Chemistry

In this work, phthalonitrile (3) and zinc(II) phthalocyanine (4) were prepared. To determine the photodynamic therapy potential of compound 4, singlet oxygen quantum yield, DNA binding and cleavage, and topoisomerase I inhibition experiments were performed. The singlet oxygen quantum yield value of compound 4 was found higher than that of the standard unsubstituted zinc(II) phthalocyanine compound (Std-ZnPc). The binding experiments showed that compound 4 interacted with ct-DNA strongly via nonintercalation mode. pBR322 plasmid DNA cleavage activity of the compound was investigated using agarose gel electrophoresis. The results showed that the compound 4 had important DNA cleavage activity. The E. coli …


Synthesis And Characterization Of Unsaturated Diacyl And Alkyl-Acyl Piperazine Derivatives, Sai̇t Sari, Seda Ünalan, Mehmet Yilmaz Jan 2019

Synthesis And Characterization Of Unsaturated Diacyl And Alkyl-Acyl Piperazine Derivatives, Sai̇t Sari, Seda Ünalan, Mehmet Yilmaz

Turkish Journal of Chemistry

The aim of this study is to obtain new unsaturated piperazine compounds by the reactions of piperazine (1a) and piperazine derivatives (1b-1d) with acylation reactive groups (a-2j). Methacryloyl piperazine (1b) was synthesized from the reaction of methacrylic anhydride with piperazine (1a). Acyl chlorides (2b-2d) were prepared from the reaction of thionyl chloride with carboxylic acids (3a-3c) obtained as a result of the reaction with malonic acid and suitable aldehyde (5-methylfuran-2-carbaldehyde for 3a, cinnamaldehyde for 3b, and thiophene-2-carbaldehyde for 3c), respectively, by literature methods. Acyl chlorides 2ed and 2f }were obtained from the reaction of commercially purchased carboxylic acids 3d and …


Aqueous Two-Phase Extraction Technique Based On Magnetic Ionic Liquid-Nonionic Surfactant For Phenolic Acids In Grape, Apple, Pear, And Banana, Taşkin Mumcu, Serap Seyhan Bozkurt Jan 2019

Aqueous Two-Phase Extraction Technique Based On Magnetic Ionic Liquid-Nonionic Surfactant For Phenolic Acids In Grape, Apple, Pear, And Banana, Taşkin Mumcu, Serap Seyhan Bozkurt

Turkish Journal of Chemistry

An aqueous two-phase extraction system was constituted using magnetic ionic liquid-nonionic surfactant for phenolic acids and the developed method was applied to apple, grape, pear, and banana samples. Ionic liquids based on imidazolium containing butyl, allyl, and benzyl groups were used for extraction. The parameters influencing the extraction efficiency such as volume of ionic liquids, type and amount of surfactant and salt, ultrasound extraction time, temperature, and sample pH were optimized. The extraction efficiencies of ionic liquids were compared for phenolic acids under optimized conditions. Limits of detection and limits of quantification were in the range of 1.34-1.56 μg L$^{-1\, …


Surface Modification Of Polyvinyl Chloride By Polyacrylic Acid Graftas A Polyelectrolyte Membrane Using Ar Plasma, Alaa Fahmy, Mouhamed Abu-Saied, Nasser Morgan, Walid Qutop, Hassan Abdelbary, Tarek Salama Jan 2019

Surface Modification Of Polyvinyl Chloride By Polyacrylic Acid Graftas A Polyelectrolyte Membrane Using Ar Plasma, Alaa Fahmy, Mouhamed Abu-Saied, Nasser Morgan, Walid Qutop, Hassan Abdelbary, Tarek Salama

Turkish Journal of Chemistry

This work reports the synthesis and properties of a new membrane based on polyvinyl chloride (PVC) grafting with polyacrylic acid (PAA) using argon (Ar) plasma. The membranes of PVC were synthesized by solution-casting method, where PAA was deposited as an ultrathin film onto PVC using dielectric barrier discharge at atmospheric pressure with Ar gas. The surface characteristics and chemical composition of the modified membranes were analyzed by water contact angle, scanning electron microscopy, and Fourier transform infrared spectroscopy. Moreover, the electrochemical properties of the membrane were investigated via ion exchange capacity for the purpose of using it as a polyelectrolyte …


An Ultrasensitive Electrochemical Immunosensor Platform Based On Disposable Ito Electrode Modified By 3-Cptms For Early Detection Of Parathyroid Hormone, İnci̇ Uludağ, Mustafa Kemal Sezgi̇ntürk Jan 2019

An Ultrasensitive Electrochemical Immunosensor Platform Based On Disposable Ito Electrode Modified By 3-Cptms For Early Detection Of Parathyroid Hormone, İnci̇ Uludağ, Mustafa Kemal Sezgi̇ntürk

Turkish Journal of Chemistry

Parathyroid hormone (PTH) is a polypeptide containing 84 amino acids secreted by cells of the parathyroid glands. Imbalances of parathyroid levels cause medical problems such as osteoporosis, mental disorders, pancreatitis, kidney stones, cancer, and other symptoms. In this study, we aimed to design an ultrasensitive electrochemical immunosensor for PTH detection. Indium tin oxide (ITO) was used as an electrode for electrochemical impedance spectroscopy (EIS) measurements. ITO sheets were modified by using 3-cyanopropyltrimethoxysilane (3-CPTMS) self-assembled monolayers (SAMs) for immobilizing the anti-PTH antibody via covalent interactions. Cyclic voltammetry (CV) and EIS methods were applied to characterize immobilization steps. Therefore, 1% was selected …


The Role Of Diazacrown Ether In The Enhancement Of The Biological Activity Of Silver Nanoparticles, Sarvinaz Hajiyeva, Ulviyya Hasanova, Zarema Gakhramanova, Aygun Israyilova, Khudaverdi Ganbarov, Eldar Gasimov, Fuad Rzayev, Goncha Eyvazova, Alakbar Huseynzada, Gunel Aliyeva, Ilaha Hasanova, Abel Maharramov Jan 2019

The Role Of Diazacrown Ether In The Enhancement Of The Biological Activity Of Silver Nanoparticles, Sarvinaz Hajiyeva, Ulviyya Hasanova, Zarema Gakhramanova, Aygun Israyilova, Khudaverdi Ganbarov, Eldar Gasimov, Fuad Rzayev, Goncha Eyvazova, Alakbar Huseynzada, Gunel Aliyeva, Ilaha Hasanova, Abel Maharramov

Turkish Journal of Chemistry

The nanostructuring of hydroxyl-substituted diazacrown-ether (DC) by silver nanoparticles was obtained by green synthesis method in order to increase the antibacterial activity of silver nanoparticles. The synthesized DC, nanoparticles, and nanosupramolecular complex (Ag@DC) were studied by TEM, powder-XRD, and NMR, IR, and UV spectroscopy methods. The Ag@DC nanostructures were uniform and their sizes ranged from 8 to 18 nm. IR and UV spectra revealed the noncovalent formation of the nanosupramolecular complex. The antibacterial activities of the prepared active agents were investigated on gram-positive and gram-negative bacteria by twofold microdilution method. Ultrastructural study by TEM was performed on \textit{E. coli} BDU12 …


Coefficient Estimates For A Class Containing Quasi-Convex Functions, Osman Altintaş, Öznur Özkan Kiliç Jan 2018

Coefficient Estimates For A Class Containing Quasi-Convex Functions, Osman Altintaş, Öznur Özkan Kiliç

Turkish Journal of Mathematics

In the present study, we introduce the classes $\mathcal {Q_{CV}}\left(\mu, A,B \right)$ and $\mathcal{Q_{ST}}\left(\eta, A,B \right)$. Furthermore, we obtain coefficient bounds of these classes.


On The Chebyshev Coefficients For A General Subclass Of Univalentfunctions, Şahsene Altinkaya, Si̇bel Yalçin Tokgöz Jan 2018

On The Chebyshev Coefficients For A General Subclass Of Univalentfunctions, Şahsene Altinkaya, Si̇bel Yalçin Tokgöz

Turkish Journal of Mathematics

In this work, considering a general subclass of univalent functions and using the Chebyshev polynomials, we obtain coefficient expansions for functions in this class.


Linear Methods Of Summing Fourier Series And Approximation In Weighted Orliczspaces, Sadulla Jafarov Jan 2018

Linear Methods Of Summing Fourier Series And Approximation In Weighted Orliczspaces, Sadulla Jafarov

Turkish Journal of Mathematics

In the present work, we investigate estimates of the deviations of the periodic functions from the linear operators constructed on the basis of its Fourier series in reflexive weighted Orlicz spaces with Muckenhoupt weights. In particular, the orders of approximation of Zygmund and Abel-Poisson means of Fourier trigonometric series were estimated by the $k-th$~modulus of smoothness in reflexive weighted Orlicz spaces with Muckenhoupt weights.


The Diameter Vulnerability Of The Generalized Petersen Graph ${Gp[Tk,K]}$, Gülnaz Boruzanli Eki̇nci̇, John Baptist Gauci Jan 2018

The Diameter Vulnerability Of The Generalized Petersen Graph ${Gp[Tk,K]}$, Gülnaz Boruzanli Eki̇nci̇, John Baptist Gauci

Turkish Journal of Mathematics

The diameter of a graph gives the length of the longest path among all the shortest paths between any two vertices of the graph, and the diameter vulnerability problem measures the change in the diameter upon the deletion of edges. In this paper we determine the diameter vulnerability of the generalized Petersen graph $GP[tk,k]$, for integers $t\geq 2$ and $k\geq 1$, and show that (except for some small cases) the diameter remains unchanged upon the deletion of one edge. This work contributes towards a solution of the well-known $(\Delta, D, D', s)$-problem, which attempts to find large graphs with maximum …


Construction Of The Second Hankel Determinant For A New Subclass Ofbi-Univalent Functions, Şahsene Altinkaya, Si̇bel Yalçin Tokgöz Jan 2018

Construction Of The Second Hankel Determinant For A New Subclass Ofbi-Univalent Functions, Şahsene Altinkaya, Si̇bel Yalçin Tokgöz

Turkish Journal of Mathematics

In this paper, we will discuss a newly constructed subclass of bi-starlike functions. Furthermore, we establish bounds for the coefficients and get the second Hankel determinant for the class $S_{\Sigma }(\alpha ,\beta ).$


Description Of Invariant Subspaces In Terms Of Berezin Symbols, Suna Saltan Jan 2018

Description Of Invariant Subspaces In Terms Of Berezin Symbols, Suna Saltan

Turkish Journal of Mathematics

We consider the stretching operator $\left( T_{w}f\right) \left( z\right) =f(wz)$ and the multiple shift operator $S^{n}f=z^{n}f$ on the Hardy spaces $% H^{p}(\mathbb{D})$ $\left( 1\leq p


Free Modules And Crossed Modules Of $R$-Algebroids, Osman Avcioğlu, İbrahi̇m İlker Akça Jan 2018

Free Modules And Crossed Modules Of $R$-Algebroids, Osman Avcioğlu, İbrahi̇m İlker Akça

Turkish Journal of Mathematics

In this paper, first, we construct the free modules and precrossed modules of $R$-algebroids. Then we introduce the Peiffer ideal of a precrossed module and use it to construct the free crossed module.


Generalization Of The Cayley Transform In 3d Homogeneous Geometries, Zlatko Erjavec Jan 2018

Generalization Of The Cayley Transform In 3d Homogeneous Geometries, Zlatko Erjavec

Turkish Journal of Mathematics

The Cayley transform maps the unit disk onto the upper half-plane, conformally and isometrically. In this paper, we generalize the Cayley transform in three-dimensional homogeneous geometries which are fiber bundles over the hyperbolic plane. Obtained generalizations are isometries between existing models in corresponding homogeneous geometries. Particularly, constructed isometry between two models of { $\widetilde{SL(2,\mathbb{R})}$} geometry is nontrivial and enables comparison and transfer of known and even future results between these two models.


Trigonometric Expressions For Infinite Series Involving Binomial Coefficients, Nadia Li Jan 2018

Trigonometric Expressions For Infinite Series Involving Binomial Coefficients, Nadia Li

Turkish Journal of Mathematics

By means of the hypergeometric series approach, we present a new proof of Sun's conjecture on trigonometric series, which is simpler than the original one due to Sun and Meng. Several further infinite series identities are shown as examples.


On The Asymptotic Behavior Of Solution Of Certain Systems Of Volterra Equations, Ewa Schmeidel, Malgorzata Zdanowicz Jan 2018

On The Asymptotic Behavior Of Solution Of Certain Systems Of Volterra Equations, Ewa Schmeidel, Malgorzata Zdanowicz

Turkish Journal of Mathematics

This paper is concerned with the asymptotic property of the solution of a system of the linear Volterra difference equations. The criterion for the existence of a solution of the considered system that is asymptotically equivalent to a given sequence is established. %The results generalize some recent results. The results presented here improve and generalize the results published by Diblik et al. Unlike in those works, here periodicity of the nonhomogeneous term of the equation is not assumed. Examples illustrate the obtained results.


Almost Paracontact Structures Obtained From $G_{2(2)}^*$ Structures, Nüli̇fer Özdemi̇r, Şi̇ri̇n Aktay, Mehmet Solgun Jan 2018

Almost Paracontact Structures Obtained From $G_{2(2)}^*$ Structures, Nüli̇fer Özdemi̇r, Şi̇ri̇n Aktay, Mehmet Solgun

Turkish Journal of Mathematics

In this paper, we construct almost paracontact metric structures by using the fundamental 3-forms of manifolds with $G_{2(2)}^*$ structures. The existence of certain almost paracontact metric structures is investigated due to the properties of the 2-fold vector cross-product. Furthermore, we give some relations between the classes of $G_{2(2)}^*$ structures and almost paracontact metric structures.


On Hochstadt--Lieberman Theorem For Impulsive Sturm-Liouville Problems With Boundary Conditions Polynomially Dependent On The Spectral Parameter, Seyfollah Mosazadeh, Aliasghar Jodayree Akbarfam Jan 2018

On Hochstadt--Lieberman Theorem For Impulsive Sturm-Liouville Problems With Boundary Conditions Polynomially Dependent On The Spectral Parameter, Seyfollah Mosazadeh, Aliasghar Jodayree Akbarfam

Turkish Journal of Mathematics

In the present paper, we consider an inverse problem for the Sturm-Liouville operator with a finite number of discontinuities at interior points and boundary conditions polynomially dependent on the spectral parameter on an arbitrary finite interval, and prove the Hochstadt-Lieberman-type theorem for this problem.


Several Hardy-Type Inequalities With Weights Related To Baouendi--Grushinoperators, Abdullah Yener Jan 2018

Several Hardy-Type Inequalities With Weights Related To Baouendi--Grushinoperators, Abdullah Yener

Turkish Journal of Mathematics

In this paper we shall prove several weighted $L^{p}$ Hardy-type inequalities associated to the Baouendi-Grushin-type operators $\Delta _{\gamma }=\Delta _{x}+\left\vert x\right\vert ^{2\gamma }\Delta _{y},$ where $\Delta _{x}$ and $\Delta _{y}$ are the classical Laplace operators in the variables $x\in \mathbb{R}^{n}$ and $y\in \mathbb{R}^{k},$ respectively, and $\gamma $ is a positive real number.


Linearized Four-Step Implicit Scheme For Nonlinear Parabolic Interface Problems, Matthew Olayiwola Adewole, Victor Folarin Payne Jan 2018

Linearized Four-Step Implicit Scheme For Nonlinear Parabolic Interface Problems, Matthew Olayiwola Adewole, Victor Folarin Payne

Turkish Journal of Mathematics

We present the solution of a second-order nonlinear parabolic interface problem on a quasiuniform triangular finite element with a linearized four-step implicit scheme used for the time discretization. The convergence of the scheme in $L^2$-norm is established under certain regularity assumptions using interpolation and elliptic projection operators. A numerical experiment is presented to support the theoretical result. It is assumed that the interface cannot be fitted exactly.


Radii Of Uniform Convexity Of Some Special Functions, İbrahi̇m Aktaş, Evri̇m Toklu, Hali̇t Orhan Jan 2018

Radii Of Uniform Convexity Of Some Special Functions, İbrahi̇m Aktaş, Evri̇m Toklu, Hali̇t Orhan

Turkish Journal of Mathematics

In this investigation our main aim is to determine the radii of uniform convexity of selected normalized $ q $-Bessel and Wright functions. Here we consider six different normalized forms of $ q $-Bessel functions and we apply three different kinds of the normalization of the Wright function. We also show that the obtained radii are the smallest positive roots of some functional equations.


Transversal Lightlikesubmanifolds Of Metallic Semi-Riemannian Manifolds, Feyza Esra Erdoğan Jan 2018

Transversal Lightlikesubmanifolds Of Metallic Semi-Riemannian Manifolds, Feyza Esra Erdoğan

Turkish Journal of Mathematics

The main purpose of the present paper is to study the geometry of transversal lightlike submanifolds and radical transversal lightlike submanifolds of metallic semi-Riemannian manifolds. We investigate the geometry of distributions and obtain necessary and sufficient conditions for the induced connection on these manifolds to be a metric connection. We also obtain characterization of transversal lightlike submanifolds of metallic semi-Riemannian manifolds. Finally, we give two examples.


Inequalities For Submanifolds Of Sasaki-Like Statistical Manifolds, Hülya Bostan Ayti̇mur, Ci̇han Özgür Jan 2018

Inequalities For Submanifolds Of Sasaki-Like Statistical Manifolds, Hülya Bostan Ayti̇mur, Ci̇han Özgür

Turkish Journal of Mathematics

We consider statistical submanifolds in Sasaki-like statistical manifolds. We give some examples of invariant and antiinvariant submanifolds of Sasaki-like statistical manifolds. We prove Chen-like inequality involving scalar curvature and Chen-Ricci inequality for these kinds of submanifolds.