Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Keyword
-
- Turkey (129)
- 1 (99)
- 2 (83)
- Classification (75)
- Deep learning (75)
-
- Machine learning (72)
- Optimization (69)
- Genetic algorithm (62)
- Synthesis (62)
- Adsorption (58)
- Geochemistry (55)
- Particle swarm optimization (53)
- Antimicrobial activity (47)
- 3 (45)
- Artificial neural network (42)
- Stability (40)
- Support vector machine (37)
- Phthalocyanine (36)
- Antibacterial activity (33)
- Feature extraction (33)
- Artificial neural networks (32)
- Feature selection (31)
- Wireless sensor networks (31)
- Molecular docking (30)
- Copper (28)
- Cytotoxicity (28)
- DFT (28)
- Oscillation (28)
- Power quality (28)
- COVID-19 (27)
- Publication Year
Articles 11881 - 11910 of 12072
Full-Text Articles in Entire DC Network
An Application Of Monodromy Groupoid, Osman Mucuk
An Application Of Monodromy Groupoid, Osman Mucuk
Turkish Journal of Mathematics
The monodromy groupoid was first inlioduced by Pradines in [7] and developed by Mucuk in [6] In this paper we give an application of the monodromy groupoid.
Locally Topological Groupoids, Osman Mucuk
Locally Topological Groupoids, Osman Mucuk
Turkish Journal of Mathematics
The notion of Iocally topological groupoid was introduced by Aof and Brown in [2]. On the other hand in [6] by Mackenzie a topological groupoid MG, called monodromy groupoid, is constructed. In this paper we prove that this groupoid MG gives a Iocally topological groupoid.
The Spectra And Fine Spectra For P-Cesáro Operators, Cafer Coşkun
The Spectra And Fine Spectra For P-Cesáro Operators, Cafer Coşkun
Turkish Journal of Mathematics
In [6], Rhaly computed the spectrum of p-Cesaro operator on the Hilbert space l_2 = {x = (x_k): \Sigma_k IX_kl^2 < infinite}. In the present paper, we study the spectrum and fine spectrum for p-Cesáro operators acting on C_o, the space of null sequences.
Painlevé Analysis And Infinite Lie Symmetries Of The Complex Modified Korteweg-De Vries-Ii Equation, Abulgassim Ali Muhammad, Mehmet Can
Painlevé Analysis And Infinite Lie Symmetries Of The Complex Modified Korteweg-De Vries-Ii Equation, Abulgassim Ali Muhammad, Mehmet Can
Turkish Journal of Mathematics
The Painleve analysis developed by Weiss et al. [9] for nonlinear partial differential equations is applied to the CMKdV-II equation. It has been shown that this equation passes the Painleve test. By specializing the arbitrary functions that appear in the phi series expansions found in the test, one obtains a system of partial differential equations for the formally arbitrary data. For specific systems, and conjectured in general, these equations are integrable. The form of the resulting reduction enables the identification of integrable reductions of the original systems. Assuming u_i = \upsilon_i = 0, i >= 2 we obtain conditions to …
Augmented Graded Rings, Mashhoor Refai
Augmented Graded Rings, Mashhoor Refai
Turkish Journal of Mathematics
In this paper we study the augmented graded rings and give the ralationship between these rings and stronger properties of graded rings.
On The Theory Of A Certain Class Of Quadratic Pencils Of Matrices And Its Applications, G.Sh. Guseinov, G. Oturanç
On The Theory Of A Certain Class Of Quadratic Pencils Of Matrices And Its Applications, G.Sh. Guseinov, G. Oturanç
Turkish Journal of Mathematics
This paper is devoted to the study of the properties of eigenvalues and eigenvectors of quadratic pencil \lambda^2C - \lambdaR - J , where C is a positive diagonal matrix, R is an arbitrary real diagonal matrix, J is a ,, tridiagonal" real symmetric and positive matrix. The obtained results are then used to solve the corresponding system of differential equations with boundary and initial conditions. Kev Words: Quadratic pencijs, eigenvalues, eigenvectors.
Near Ultrafilters And Luc-Compactification Of Real Numbers, Mahmut Koçak
Near Ultrafilters And Luc-Compactification Of Real Numbers, Mahmut Koçak
Turkish Journal of Mathematics
In this work we will investigate some of the topological properties of the Luc compactification of real numbers R in terms of the concept of near ultrafilters.
On The Solution Of The E.P.D. Equation Using Finite Integral Transformations, Neşe Dernek
On The Solution Of The E.P.D. Equation Using Finite Integral Transformations, Neşe Dernek
Turkish Journal of Mathematics
In this paper, a solution is given for the following initial boundary value problem: \Delta=u_{tt}+k/t+u_t+g(x, t) (t>0) u(0, t)=u(a, t)=0 u(x, 0)=f(x), u_t(x, 0)=0 where x, a \epsilon R^n, t is the time variable, k < 1, k ? -1, -2, -3, . . . is a real parameter, \Delta is the n dimensional Laplace operator, f and g real analytic functions. The equation in this problem is known as the nonhomogeneous Euler-Poisson-Darboux (E.P.D.) Equation. The solution is obtained using finite integral transformation technique and is the sum of two uniformly and absolutely convergent power series.
Locally Nilpotent P-Groups Whose Proper Subgroups Are Nc-Groups, A.O. Asar, A. Yalincaklioğlu
Locally Nilpotent P-Groups Whose Proper Subgroups Are Nc-Groups, A.O. Asar, A. Yalincaklioğlu
Turkish Journal of Mathematics
Let G be a locally nilpotent p-group in which every proper subgroup is an NC-group. It is shown that G is itself an NC-group if either (i) the normal closure of every finite subgroup of G is a Chernikov extension of a CC-group or (ii) every proper normal subgroup of G is the union of an ascending chain of normal CCsubgroups.
Kinetics Of Autoxidative Polymerization Of Sunflowerseed Oil, Hüseyin Topallar, Yüksel Bayrak, Mehmet İşcan
Kinetics Of Autoxidative Polymerization Of Sunflowerseed Oil, Hüseyin Topallar, Yüksel Bayrak, Mehmet İşcan
Turkish Journal of Chemistry
The rates of polymerization of unhydrogenated and hydrogenated sunflowerseed oils were measured under atmospheric conditions in the various containers (glass, PET and metal). Polymerization rates showed a strong dependence on the degree of unsaturation and the light transmittance of the containers. The average molecular weights of polymerized oils were determined by viscosity measurements.The relationship between viscosity and average molecular weight was determined. It is seen that unhydrogenated sunflowerseed oil has a higher polymerization rate than hydrogenated oil samples in a glass container and they has higher viscosity values.
Apocarbonic Anhydrase-Enzymatic Determination Of Zinc In Fruit Juices, Ayşe Karagölge, Nazan Demi̇r, Yaşar Demi̇r, İrfan Küfrevi̇oğlu
Apocarbonic Anhydrase-Enzymatic Determination Of Zinc In Fruit Juices, Ayşe Karagölge, Nazan Demi̇r, Yaşar Demi̇r, İrfan Küfrevi̇oğlu
Turkish Journal of Chemistry
In this study, a new enzymatic method for determining trace amount of zinc was employed on ten different fruit juices. The basis of the enzymatic method is that apocarbonic anhydrase regains its activity in proportion to the Zn^{2+} existing in a solution. Thus, the more activated the enzyme is in the medium, the higher the Zn^{2+} concentration in the solution will be. For this purpose, bovine carbonic anhydrase was purified from erythrocyte hemolisate by affinity chromatography. The Zn^{2+} bound to the enzyme was removed by of the purified enzyme against the solution of pyridine-2-6-dicarboxylic acid. Thus 100\% purified enzyme was …
Investigation Of Hmo Spectra Of Hückel And Mobius Type Cyclacenes, Lemi Türker, Şakir Erkoç
Investigation Of Hmo Spectra Of Hückel And Mobius Type Cyclacenes, Lemi Türker, Şakir Erkoç
Turkish Journal of Chemistry
The Hückel molecular orbital spectra (HMO) of Hückel- and Mobius-type cyclacenes having 3-15 benzenoid rings were investigated and it was found that certain eigenvalues are topologically invariant, whereas others exhibit topological periodicity. For example, Hückel-type cyclacenes having 2r (r: 2,3,4,...) benzenoid rings which possess nonbonding molecular orbitals (NBMO) and are thus expected to be open shell structures.
Investigation Of H-Bond On Fluorescence Changes In Benzene Derivations And Different Acceptor Systems, Nursel Acar Bayri, Özgül Koçak
Investigation Of H-Bond On Fluorescence Changes In Benzene Derivations And Different Acceptor Systems, Nursel Acar Bayri, Özgül Koçak
Turkish Journal of Chemistry
In this study, benzene derivatives of phenol and naphtol were selected as donor systems and mixed with dioxane and TEA (triethylamine), which were chosen as acceptors. H-bond formation in the phenol-triethylamine binary system was investigated by both UV absorption and emission spectroscopies. The changes in the absorption and emission spectra by H-bond formation and the equilibrium of the H-bonded complexes were studied at both the ground and excited states. In addition, equilibrium constants at different temperatures and thermodynamic properties related to equilibrium (enthalpy, fere energy change and entropy values of H-bond formation) were calculated. A shift to longer wavelengths and …
Conducting Polymer Grafts Of Polypyrrole, Levent Toppare
Conducting Polymer Grafts Of Polypyrrole, Levent Toppare
Turkish Journal of Chemistry
Conducting polymer grafts of pyrrole with poly[(methyl methacrylate)-co-(2-(N-pyrollyl) ethyl methacrylate)] wwere synthesized via elctrochemical polymerization of pyrrole in different media. Samples were characterized by SEM, thermal analysis and conductivity measurements.
Calculation Of Spreading Pressure Of Water On Cellulosic Films From Contact Angle Data, H. Yıldırım Erbi̇l
Calculation Of Spreading Pressure Of Water On Cellulosic Films From Contact Angle Data, H. Yıldırım Erbi̇l
Turkish Journal of Chemistry
The correlations between the surface properties of the modified cellulose papers with their toner compatibility were investigated. The surface tension components of the cellulosic films, their interfacial tension with the liquid drops and the work of adhesion components were calculated using van Oss-Good's One-Liquid contact angle approach. The electron donor (or Lewis base) \gamma^- components of the cellulosic films were found to represent the main interactions with the the electron acceptor (acidic) \gamma^+ components of the contacting liquids. Allyl ketene dimer (AKD) grafting of the cellulose affected the surface properties; the higher the substitution of the hydroxyl group, the smaller …
Features Of Graft Copolymer Formation Through Reaction Of Functionalized Polyolefins With Poly-\Epsilon-Caprolactam, Elisa Passaglia, Francesco Picchioni, Mauro Aglietto, Giocomo Ruggeri, Francesco Ciardelli
Features Of Graft Copolymer Formation Through Reaction Of Functionalized Polyolefins With Poly-\Epsilon-Caprolactam, Elisa Passaglia, Francesco Picchioni, Mauro Aglietto, Giocomo Ruggeri, Francesco Ciardelli
Turkish Journal of Chemistry
The reaction in the melt of polyolefins containing 2-diethylsuccinate groups (DES) with poly-\epsilon-caprolactam (PA6) to give a graft copolymer was investigated under different conditions. Even using a large excess of DES groups over the PA6 terminal amino groups the graft copolymer yield resulted only partial thus suggesting a kinetic control of the reaction. The effect of various catalysts was then examined taking into account results obtained in a model reaction between a low molecular weight amine and diethylsuccinate. The results are discussed in terms of side reactions and miscibility of the pristine polymers.
Synthesis And Characterisation Of Anhydrous Magnesium Phosphate Mg$_3$(Po$_4$)$_2$, A. Baykal, M. Kizilyalli, R. Kniep
Synthesis And Characterisation Of Anhydrous Magnesium Phosphate Mg$_3$(Po$_4$)$_2$, A. Baykal, M. Kizilyalli, R. Kniep
Turkish Journal of Chemistry
The synthesis and characterization of anhydorus Mg_3(PO$_4)_2 was investigated. Mg_3(PO$_4)_2 is reported to have similar structural arrangements with Co_3(PO_4)_2 and \gamma-Zn_3(PO_4)_2 compounds. The sample was prepared by a new technique which is the reaction of MgCl_2.6H_2O and Na_3PO_4.12H_2O solutions at pH=5.1, which was adjusted by adding concentrated H_3PO_4 to the reaction mixture and heating the precipitated product at 600^{\circ}C untill constant weight. The purity of the product was checked by X-ray powder diffraction, IR, density measurement, SEM and DTA analysis. The monoclinic unit cell dimensions of product are a=7.605 (2), b=8.233 (3), c=5.080 (1)A^{\circ} and \beta= 94.19^{\circ} (3), which was …
A Study Of The Thermodynamical Interactions Of Bisphenol-A Polycarbonate With Some Solvents By Gas Chromatography, Özlem Cankurtaran, Ferdane Yilmaz
A Study Of The Thermodynamical Interactions Of Bisphenol-A Polycarbonate With Some Solvents By Gas Chromatography, Özlem Cankurtaran, Ferdane Yilmaz
Turkish Journal of Chemistry
Retentin diagrams of polycarbonate for n-nonane, ethyl acetate and n-butyl acetate were obtained using inverse gas chromatography in the temperature range 80-240^{\circ}C. The specific retention volumes, V^{\circ}_{g} the Flory-Huggins interaction parmeters, \chi^{\infty}_{12}, interaction parameters, \chi^{\ast}_{12}, and effective exchange-energy parameters \bar{X}_{12} of the equation-of-state theory of polycarbonate for n-octane, n-nonane, n-decane, ethyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, tert-butyl acetate and isoamyl acetate were obtained in the temperature range 200-240^{\circ}C. The parameter \delta_2 was estimated to be 10.7 (cal/cm^3)^{1/2} at room temperature using the \chi^{\infty}_{12} extrapolated to room temperature. Keywords: Bisphenol-A polycarbonate, polymer-solvent interactions, inverse gas chromatography, solubility parameter.
Reduction Of Combustion Generated Pollution: Process Modifications And Energy Efficient Power Cycles, Janos M. Beer
Reduction Of Combustion Generated Pollution: Process Modifications And Energy Efficient Power Cycles, Janos M. Beer
Turkish Journal of Chemistry
Theoretical bases of combustion process modifications aimed at the reduction of pollutant emission are examined. It is shown, as an example, of how the minimization of emissions of nitrogen oxides leads to a design protocol that translates results of modeling and of bench scale experiments into guidelines for industrial design. The formation and emission of polycyclic aromatic compounds is also considered, because their formation is strongly favored in "low NO_x flames". In power generation the pollutant emission can be reduced effectively by the improvement of the ``heat rate,"i.e., the thermodynamic efficiency of the power cycle. Combined gas turbine-steam cycles which …
Novel Architectures Of Macromolecular Systems, Gerhard Wegner
Novel Architectures Of Macromolecular Systems, Gerhard Wegner
Turkish Journal of Chemistry
An important thrust in modern macromolecular chemistry is to construct complex architectures either directly from monomer units, or to design macromolecules capable of forming a desired superstructure by self-organization. Chain-rigidity is an example of a structural principle leading to self organization depending on the aspect ratio of the molecular objects and their mutual interactions. These molecularly defined objects serve as the building blocks of systems for which ultrathin layers composed of hairy rod macromolecules (HRM) are an example. Depending on architectural details layered architectures of HRM are models for molecular nanocomposites, exhibit interesting optical, electrochemical, dielectric or barrier properties. They …
Polymer Light Emitting Diodes, Frank E. Karasz, Bin Hu, Zhou Yang
Polymer Light Emitting Diodes, Frank E. Karasz, Bin Hu, Zhou Yang
Turkish Journal of Chemistry
Polyphenylene vinylene-based conjugated-nonconjugated alternating block copolymers form the active chromophores in a series of light emitting diodes (LEDs). The quantum efficiency and brightness of these devices can be improved by several orders of magnitude by incorporation of appropriate carrier transport layers and by rational choice of electrodes. Further improvements can be gained by blending of the active chromophores with high or low molecular weight species.
Antifungal Natural Products From Medicinal Plants Of Pakistan, Atta Rahman, M. I. Choudhary
Antifungal Natural Products From Medicinal Plants Of Pakistan, Atta Rahman, M. I. Choudhary
Turkish Journal of Chemistry
A number of diseases in humans, animals, insects and plants are caused by pathogenic fungi. Several fungi also produce toxins in foods and can cause poisoning. Antifungal compounds are therefore important both for controlling serious fungal diseases of animals and plants, and for preserving food and other organic materials against attack by fungi. Our work on antifungal phytochemicals of medicinal plants has resulted in the isolation of a number of interesting compounds. The agar diffusion method was used to determine the antifungal activity of the pure isolates and extracts against a number of highly pathogenic fungi. The structures of the …
Analytical Applications Of Organic Conducting Polymer Electrodes, Nada F. Atta, George C. Russell, Z. Wang, N. Akmal, J.F. Rubinson, S.K. Lunsford, E. Karagözler, O. Y. Ataman, H. Zimmer, H.B. (Jr.) Mark, Ahmed Galal
Analytical Applications Of Organic Conducting Polymer Electrodes, Nada F. Atta, George C. Russell, Z. Wang, N. Akmal, J.F. Rubinson, S.K. Lunsford, E. Karagözler, O. Y. Ataman, H. Zimmer, H.B. (Jr.) Mark, Ahmed Galal
Turkish Journal of Chemistry
Electrodes modified by he electrodeposition of conducting polymers were used for the detection and quantitative determination of some inorganic, organic, and biological molecules. Monomers used were five membered ring heterocycles or crown ethers and their derivatives. The polymer films were deposited on glassy carbon or platinum substrates. The resulting electrodes were used in the amperometric mode or in the potentiometric mode for flow injection and chromatographic analyses. The results showed that the proposed modified surface catalyzes the oxidation of organic and biological compounds. The detection of electroinactive inorganic anions, such as F^-, Cl^-, Br^-, NO_2^- and NO^-_3 was also possible …
Synthesis And Characterization Of Conducting Polymers And Their Composites, L. Toppare
Synthesis And Characterization Of Conducting Polymers And Their Composites, L. Toppare
Turkish Journal of Chemistry
Blends of conducting polymers polypyrrole and polyaniline, in the insulating host polymers, polybisphenol A carbonate, polyamide and polyamide have been prepared electrochemically. Composite homogeneity and a possible chemical interaction between the host matrices and the conducting polymers were searched. Several spectroscopic and thermal analyses of free standing films suggest such an interaction.
Dissociation Dynamics Of Small Carbon Clusters, Ersin Yurtsever, Nuran Elmaci
Dissociation Dynamics Of Small Carbon Clusters, Ersin Yurtsever, Nuran Elmaci
Turkish Journal of Chemistry
The dissociation dynamics of small carbon clusters is studied by classical trajectory analysis. A large number of initial conditions are chosen to analyze the effects of the energy, angular momentum and the initial geometry of the cluster. The dissociation times, decay rate constants, kinetic energy of the dissociating atoms and the geometrical structure of the remaining part of the clusters are computed from microcanonical sampling of the phase space. Distributions of these properties as well as the possibilities of various fragmentation channels are presented.
A Computational Study On The Conformational Behaviour Of 1,1,2-Trihydroxyethane In Solution, Safiye Sağ Erdem, Tereza Varnali, Viktorya Avi̇yente
A Computational Study On The Conformational Behaviour Of 1,1,2-Trihydroxyethane In Solution, Safiye Sağ Erdem, Tereza Varnali, Viktorya Avi̇yente
Turkish Journal of Chemistry
The conformational space of 1,1,2-trihydroxyethane were investigated with the PM3 method both in gas phase and in solution. Ab initio calculations at 6-31G level were also conformational equilibria in solution were studied and used to explain the behaviour of 2-hydroxycyclohexanone propylene and ethylene ketals.
General Character Of Electrochaemically Adsorbed Cobalt On Smooth Platinum In Solutions Of Various Ph, Gülcemal Yildiz, Sadiq Kuluyev, Figen Kadirgan
General Character Of Electrochaemically Adsorbed Cobalt On Smooth Platinum In Solutions Of Various Ph, Gülcemal Yildiz, Sadiq Kuluyev, Figen Kadirgan
Turkish Journal of Chemistry
The adsorption of cobalt adatoms on to a smooth platinum electrode at different potentials was studied by voltammetric methods. The amount of cobalt coverage was determined from the hydrogen region of the platinum electrode. The number of electrons per adatom species was calculated. The experiments were carried out in the pH interval between 0-3 in H_{2}SO_{4}-containing solutions.
Synthesis And Characterization Of Complexes Of Co(Ii), Ni(Ii), Cd(Ii), Hg(Ii) And Pd(Ii) With Some N-Phenyl-N^{1}-2-[4-Phenyl-(Substituted) Thiazolyl]- Thioureas, B. Narayana, M. R. Gajendragad
Synthesis And Characterization Of Complexes Of Co(Ii), Ni(Ii), Cd(Ii), Hg(Ii) And Pd(Ii) With Some N-Phenyl-N^{1}-2-[4-Phenyl-(Substituted) Thiazolyl]- Thioureas, B. Narayana, M. R. Gajendragad
Turkish Journal of Chemistry
The Synthesis and characterization of the complexes of Co(II), Ni(II), Pd(II), Cd(II) and Hg(II) with N-phenyl-N^{1}-2(-4-phenylthiazoly)thiourea (PPT) and N-phenyl-N^{1}-2-(4-methylphenylthiazolyl)-thiourea (PMPT) and Co(II), Cd(II), and Hg(II) complexes of N-phenyl-N^{1}-2-(4-p- chlorophenylthiazolyl) thiourea (PCPT) are included in this paper. Based on analytical results, electronic and infrared spectral data and magnetic susceptibility measurements, plausible structures have been proposed.
Complexes Of Zn(Ii), Pd(Ii), Hg(Ii), Pb(Ii), Cu(I), Ag(I) And Tl(I) With 4-Amino-5-Mercapto-3-(O-Tolyloxymethyl)-1,2,4-Triazole, B. Narayana, M. R. Gajendragad
Complexes Of Zn(Ii), Pd(Ii), Hg(Ii), Pb(Ii), Cu(I), Ag(I) And Tl(I) With 4-Amino-5-Mercapto-3-(O-Tolyloxymethyl)-1,2,4-Triazole, B. Narayana, M. R. Gajendragad
Turkish Journal of Chemistry
The synthesis and characterization of complexes of Zn(II), Pd(II), Cd(II), Hg(II), Pb(II), Cu(I), Ag(I), and Tl(I) with 4-amino-5-mercapto-3-(o- tolyloxymethyl)-1,2,4-triazole are described. Based on analytical results, electronic and infrared spectral data and magnetic susceptibility measurements suitable structures have been proposed.