Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Physical Sciences and Mathematics (10730)
- Computer Engineering (3106)
- Computer Sciences (3106)
- Electrical and Computer Engineering (3106)
- Engineering (3106)
-
- Chemistry (2730)
- Mathematics (2595)
- Medicine and Health Sciences (1863)
- Life Sciences (1816)
- Medical Sciences (1429)
- Physics (1382)
- Earth Sciences (917)
- Animal Sciences (666)
- Agriculture (623)
- Forest Sciences (623)
- Veterinary Medicine (434)
- Biology (299)
- Zoology (232)
- Botany (228)
- Plant Sciences (228)
- Keyword
-
- Turkey (166)
- 1 (99)
- 2 (85)
- Classification (75)
- Machine learning (75)
-
- Deep learning (74)
- Optimization (72)
- Genetic algorithm (62)
- Synthesis (62)
- Adsorption (57)
- Geochemistry (55)
- Antimicrobial activity (54)
- Particle swarm optimization (53)
- COVID-19 (51)
- 3 (47)
- Children (42)
- Cytotoxicity (42)
- Oxidative stress (41)
- Reliability (41)
- Stability (41)
- Antioxidant (40)
- Artificial neural network (40)
- Antibacterial activity (38)
- Phthalocyanine (36)
- Support vector machine (36)
- Quality of life (34)
- Dog (33)
- Feature extraction (33)
- Molecular docking (33)
- Antioxidant activity (31)
- Publication Year
Articles 14581 - 14610 of 15009
Full-Text Articles in Entire DC Network
Electrochemical Polymerization And Analysis Of Some Aniline Derivatives, Bekir Sari, Muzaffer Talu
Electrochemical Polymerization And Analysis Of Some Aniline Derivatives, Bekir Sari, Muzaffer Talu
Turkish Journal of Chemistry
In this study, conductive homopolymers of o-chloroaniline, p-bromoaniline and N-methylaniline were synthesized electrochemically in perchloric acidic solution and their properties were analyzed. Initially, the maximum oxidation potential values of these monomer solutions were determined by Cyclic Voltammetry (CV). Their conductive polymers were then synthesized under a nitrogen atmosphere using a potentiostat. FTIR spectra were taken in order to analyze the structural properties of the resulting polymers. Thermogravimetric analysis (TGA) was conducted and surface micrographs were taken by a Scanning Electron Microscope (SEM). The conductivity levels of the polymers were determined by the Four Probe technique. Magnetic properties of the samples …
Electron Spectroscopy For Material Characterization, Ş. Süzer
Electron Spectroscopy For Material Characterization, Ş. Süzer
Turkish Journal of Chemistry
Basic principles of the two electron spectroscopic techniques, the x-ray photoelectron spectroscopy, XPS, and the Auger electron spectroscopy, AES, are given. Their utilization in material characterization are introduced through examples with application of these techniques to various surface related problems.
Fatty Acid Composition And Cholesterol Content Of Some Turkish Fish Species, Sedat İmre, Serap Sağlik
Fatty Acid Composition And Cholesterol Content Of Some Turkish Fish Species, Sedat İmre, Serap Sağlik
Turkish Journal of Chemistry
It is well known that fish lipids are effective against cardiovascular diseases due to their high contents of polyunsaturated omega-3 (n-3) fatty acids. In order to determine a suitable fish diet, the fatty acid compositions and total lipid and cholesterol contents of 9 common fish species obtained from the central fish market in Ğstanbul were determined. Palmitic (C-16:0) and oleic acid (C-18:1) were the predominant saturated and monounsaturated fatty acids. The predominant polyunsaturated fatty acids were eicosapentaenoic (C-20:5) acid and docosahexaenoic (C-22:6) acid. The amounts of cholesterol in fish lipids did not differ significantly. Sardine ({\it Sardina pilchardus}) and mackerel …
Voltammetric Determination Of Thioridazine Hydrochloride, İnci Bi̇ryol, Saadet Dermi̇ş
Voltammetric Determination Of Thioridazine Hydrochloride, İnci Bi̇ryol, Saadet Dermi̇ş
Turkish Journal of Chemistry
This study describes the optimal conditions for the determination of Thioridazine HCl (Tz-HCl) in 0.2 M sulphuric acid by voltammetry using ruthenium (Ru), platinum (Pt) and glassy carbon (GC) electrodes. A new and sensitive method is described for electrochemical determination of Tz-HCl in the concentration range $5.10^{-5} - 10^{-3}$ M (20.35-407 $\mu$gml$^{-1}$); $6.10^{-4} - 10^{-2}$ M (244.2 - 4070 $\mu$gml$^{-1}$); $10^{-4} - 10^{-3}$ M (40,7 - 407 $\mu$gml$^{-1}$), with Ru, Pt and glassy carbon electrodes, respectively. The method was applied successfully to the determination of Tz-HCl in pure form or incorporated in their representative pharmaceutical preparations. The precision of the …
Polarographic Studies On The Kinetics Of The Electrode Reaction Of 4-Benzoyl-1,5 Diphenyl Pyrazole-3-Carboxylic Acid, M. Veri̇rşen, S. Erturan
Polarographic Studies On The Kinetics Of The Electrode Reaction Of 4-Benzoyl-1,5 Diphenyl Pyrazole-3-Carboxylic Acid, M. Veri̇rşen, S. Erturan
Turkish Journal of Chemistry
The polarographic behavior of 4-Benzoyl-1,5 diphenyl pyrazole-3- Carboxylic acid (BDPPCA) in aqueous ethanol solution (76 \% v/v) at 25^oC was studied as a function of pH using Mcl buffer solution. One well-defined wave was obtained in the pH range of 3.3-5.4. This wave, corresponding to two electron reduction processes, was irreversible and diffusion controlled. However, in the pH range of 5.4-7.4 a single reversible and diffusion-controlled wave involving two electrons resulted. The kinetic parameters $(n_a, k^o_{f,h})$ were calculated by Koutecky's method. A tentative mechanism was put forward for the reduction process of depolarizer. Furthermore, the effects of different supporting electrolytes …
Determination Of Structure-Toxicity Relationship Of Amphiprotic Compounds By Means Of The Inhibition Of The Dehydrogenase Activity Of Pseudomonas Putida, Ş. Gül, D. Öztürk
Determination Of Structure-Toxicity Relationship Of Amphiprotic Compounds By Means Of The Inhibition Of The Dehydrogenase Activity Of Pseudomonas Putida, Ş. Gül, D. Öztürk
Turkish Journal of Chemistry
Aliphatic and aromatic alcohols are amphiprotic compounds which have both polar and nonpolar parts in their structure. These compounds were studied with respect to the nonreactive toxic effects on the microorganism {\it Pseudomonas putida}. The toxicity of these chemicals to aerobic bacterium {\it P. putida} was measured in terms of inhibition of dehydrogenase activity. The test results, expressed as concentration of chemicals 50\% effective in inhibition (IC$_{50}$), were correlated with their physicochemical properties such as aqueous solubility (S) and octanol-water partition coefficient (P).
Comparison Of Different Production Processes For Bioethanol, B. Çaylak, Fazilet Vardar Sukan
Comparison Of Different Production Processes For Bioethanol, B. Çaylak, Fazilet Vardar Sukan
Turkish Journal of Chemistry
In this study, ethanol was produced with the microorganism {\em Saccharomyces cerevisiae} by using sucrose as a substrate. Batch processes were tested by using the same substrate, microorganism and medium composition. {\em Saccharomyces cerevisiae}, used in the free form in the first group of experiments, was immobilized by different methods. In the second group of experiments agar, sponge and a natural material called luffa cylindrica fiber were used as support materials. The batch processes with free and immobilized microorganisms were compared with respect to efficiency and yield.
The Effectof Temperature On The Dynmaic Viscosity Of Acetone Sunflower-Seed Oil Mixtures, Hüseyin Topallar, Yüksel Bayrak
The Effectof Temperature On The Dynmaic Viscosity Of Acetone Sunflower-Seed Oil Mixtures, Hüseyin Topallar, Yüksel Bayrak
Turkish Journal of Chemistry
The effect of acetone on the dynamic viscosity of sunflower-seed oil was studied under a dynamic heating regime at temeparuters ranging from 25^oC to 50^oC at 5^oC intervals. Acetone dramatically reduced the viscosity of sunflower-seed oil. The reduction of viscosity was far less with further addition of acetone. A linear relationship was found between the density of sunflower-seed oil and temperature. The influence of a solvent on the density of the sunflower-seed oil/acetone solution can be accounted for by the mixing theory of ideal solutions, whereas the effect of temperature on the dynamic viscosity of the oil solution is best …
Further Studies On The Reaction Of Unsaturated Acids With O-Phenylenediamine And 4-Substituted O-Phenylenediamines In Acid Medium, Mashooda Hasan, Shagufta Munawar, Naeema Khan, Zahida Maqbool
Further Studies On The Reaction Of Unsaturated Acids With O-Phenylenediamine And 4-Substituted O-Phenylenediamines In Acid Medium, Mashooda Hasan, Shagufta Munawar, Naeema Khan, Zahida Maqbool
Turkish Journal of Chemistry
Condensation of methylcrotonic acid with 4-chloro-o-phenylenediamine in 4N HCl yielded 5-chloro-2-(1-isobutenyl)benzimidazole and 7-chloro-4, 4-dimethyl-1,3,4,5-tetrahydro-2H-1,5-benzodiazepin-2-one. Methacrylic acid when condensed with o-phenylenediamine in 4N HCl yielded the already reported 3-methyl-1,2,4,5-tetrahydro-2H-1,5-benzodiazepin-2-one and 2(2-propenyl)benzimidazole. Condensation of methacrylic acid with 4-chloro-o-phenylenediamine in 4N HCl yielded 5-chloro-2(2-propenyl)benzimidazole. The structures of all the purified compounds were confirmed with the help of mass and $^1$H NMR spectral analysis.
Solvent Extraction Of La^{3+} Withethylenediamine-N,N'-Ditetradecyl-N,N'-Diacetic Acid(Eddat) In Dichloromethane, Mürüvvet Yurdakoç, Halil Hoşgören
Solvent Extraction Of La^{3+} Withethylenediamine-N,N'-Ditetradecyl-N,N'-Diacetic Acid(Eddat) In Dichloromethane, Mürüvvet Yurdakoç, Halil Hoşgören
Turkish Journal of Chemistry
Ethylenediamine-N,N'-ditetradecyl-N,N'-diacetic acid (EDDAT) was synthesized for the solvent extraction of La$^{3+}$. EDDAT was prepared from ethylenediamine-N,N'-diacetic acid (EDDA) and tetradecyl bromide in a basic n-amylalcohol-ethanol-water solvent system. The structure of this new extracting reagent was identified according to spectroscopic data, i.e. $^{13}$C NMR, $^1$H NMR, and elemental analysis results. The solvent extraction of La$^{3+}$ with EDDAT in dichloromethane was studied as a function of parameters of the aqueous and organic phases. The optimal extraction conditions were determined. The extraction yield increased with a decrease in hydrogen ions in the aqueous phase. Stripping of the La$^{3+}$ loaded organic phase was achieved …
Separation Of Molybdenum, Vanadium And Nickel By Liquid-Liquid Extraction, T. Coşar, R. Zi̇yadanoğullari
Separation Of Molybdenum, Vanadium And Nickel By Liquid-Liquid Extraction, T. Coşar, R. Zi̇yadanoğullari
Turkish Journal of Chemistry
Elements in the ash of asphaltites that is used in thermal central for power generation units are Mo, V, U, Ti and Ni. The main goal of this study was to separate molybdenum, vanadium and nickel from the aqueous solution. The quantities of the above elements in solution were in the range of 50-80 ppm. The separate these elements from solution, the liquid-liquid extraction method was applied to samples. Alamine 336 was used as extractant. During the reduction-oxidation processes, single and multiple extraction methods were applied to the solution in combination. The quantities of molybdenum, vanadium and nickel in the …
Potentiometric Investigation Of The Effects Of Several Substituents On The Basicity Of Benzilidene-O-Hydroxyaniline, Esma Kiliç, Orhan Atakol, E. Canel, Zehra Ali̇beşeoğlu, Turgut Gündüz, Fitnat Köseoğlu
Potentiometric Investigation Of The Effects Of Several Substituents On The Basicity Of Benzilidene-O-Hydroxyaniline, Esma Kiliç, Orhan Atakol, E. Canel, Zehra Ali̇beşeoğlu, Turgut Gündüz, Fitnat Köseoğlu
Turkish Journal of Chemistry
Chloro-, bromo-, iodo-, nitro-, methoxy- and hydroxy-substituted benzilidene-o-hydroxyaniline were prepared in order to investigate the effects of substituents on the basicity of benzilidene-o-hydroxyaniline. For each substituent, three isomers -- ortho, meta and para -- were synthesised. Schiff bases were titrated potentiometrically with perchloric acid in nitrobenzene solvent at $25^{\circ}$C. All compounds gave well-shaped titration curves, from which half-neutralisation potentials were calculated. The trend in the values of half-neutralisation potentials of Schiff bases were explained in terms of the nature of the substituents. The applicability of the Hammett equation to the effect of substituents in Schiff bases in nitrobenzene solvent was …
On The Türker Angles In The Theory Of Total \Pi-Electron Energy, Ivan Gutman
On The Türker Angles In The Theory Of Total \Pi-Electron Energy, Ivan Gutman
Turkish Journal of Chemistry
The Türker angles $\theta, \alpha$ and $\beta$ are quantities invented by Lemi Türker, and are used in the theory of total $\pi$-electron energy $(E)$ of unsaturated conjugated hydrocarbons. We report here expressions for $\theta, \alpha$ and $\beta$ in terms of $E$ and the parameters $n$ (= half the number of carbon atoms) and $e$ (= the number of carbon-carbon bonds). The forms of these expressions are remarkably similar. Numerical calculation performed on a representative set of benzenoid hydrocarbons reveals that the dependence of the angles $\alpha$ and $\beta$ on molecular structure is very similar, and that their ratio is almost …
Thermal Behaviour Of Some Azo Dyes Containing Sterically Hindered And Water-Soluble Groups, Hasan Kocaokutgen, Zerrin Heren
Thermal Behaviour Of Some Azo Dyes Containing Sterically Hindered And Water-Soluble Groups, Hasan Kocaokutgen, Zerrin Heren
Turkish Journal of Chemistry
Thermal behaviour of six azo dyes containing steric hindered groups such as tert-butyl, sec-butyl and isopropyl, were investigated by means of thermogravimetry (TG), differential thermal analysis (DTA) and differential thermogravimetry (DTG). The thermal decomposition points and amount of volatile pyrolysis products, were determined in nitrogen atmosphere using TG, DTA and DTG curves.
Crystal And Molecular Structure Of Tris(2,6-Dichlorophenyl) Thiophosphate, Veysel T. Yilmaz, Mustafa Odabaşoğlu, R. Alan Howie
Crystal And Molecular Structure Of Tris(2,6-Dichlorophenyl) Thiophosphate, Veysel T. Yilmaz, Mustafa Odabaşoğlu, R. Alan Howie
Turkish Journal of Chemistry
The crystal structure of tris(2,6-dichlorophenyl)thiophosphate was determined by single crystal X-ray diffractometry. The structure consists of isolated molecules and each unit cell contains 8 molecules of the compound. The crystal system is monoclinic with a space group of C2/c. The P atom is bonded to three O atoms and one S atom in a distorted tetrahedron environment.
Alkaline Rocks And Geodynamics, Bernard Bonin
Alkaline Rocks And Geodynamics, Bernard Bonin
Turkish Journal of Earth Sciences
Origin of A-type alkali feldspar granites is currently the subject of a world-wide debate. Contrasting hypotheses have been proposed, which range from an entirely crustal origin to an almost complete mantle derivation. A-type alkali feldspar granites belong to either unimodal granite (rhyolite)-dominated association, or bimodal gabbro (basalt)-granite (rhyolite) suite. It is argued that (i) the ultimate mantle origin of basic to intermediate rocks is beyond doubt, (ii) highly evolved felsic rocks may be produced by other processes besides crustal involvement through anatexis and (iii) large volumes of felsic rocks are a normal and direct consequence of extensive crystal fractionation processes. …
Resonans Reflectionless Absorption Ofelectromagnetic Waves In Solutions, E. Salaev, E. Gasimov, S. Azizov, J. Qajar
Resonans Reflectionless Absorption Ofelectromagnetic Waves In Solutions, E. Salaev, E. Gasimov, S. Azizov, J. Qajar
Turkish Journal of Physics
No abstract provided.
Generalized Inverse Estimator And Comparison With Least Squares Estimator, S. Sakallıoğlu, F. Akdeniz
Generalized Inverse Estimator And Comparison With Least Squares Estimator, S. Sakallıoğlu, F. Akdeniz
Turkish Journal of Mathematics
Trenkler [13] described an iteration estimator. This estimator is defined as follows: for $0 < \gamma < 1/\lambda_i \max$ \[ \hat{\beta}_{m, \gamma} = \gamma \sum^m_{i=0} (1-\gamma X'X)^i X'y , \] where $\lambda_i$ are eigenvalues of $X'X$. In this paper a new estimator (generalized inverse estimator) is introduced based on the results of Tewarson [11]. A sufficient condition for the difference of mean square error matrices of least squares estimator and generalized inverse estimator to be positive definite (p.d.) is derived.
Tubo Ovarian Abscess: Risk Factors And Clinicalfeatures In Turkish Population, Didem Akyol, Utku Özcan, Murat Eki̇n, Tayfun Güngör, Oya Gökmen
Tubo Ovarian Abscess: Risk Factors And Clinicalfeatures In Turkish Population, Didem Akyol, Utku Özcan, Murat Eki̇n, Tayfun Güngör, Oya Gökmen
Turkish Journal of Medical Sciences
No abstract provided.
High-Power Diffusion Cooling Planar Waveguide Co_{2} Laser, E. Taal, M. S. Kiliçkaya
High-Power Diffusion Cooling Planar Waveguide Co_{2} Laser, E. Taal, M. S. Kiliçkaya
Turkish Journal of Physics
A diffusion-cooled CO_{2} laser using a coaxial waveguide is investigated theoretically. The resonator extracting the laser beam consits of two annular plane mirrors enclosing the two ends of the waveguide. A theoretical resonator model based on the vector modes of propagation in a dielectric coaxial waveguide is described.
Alpha Particle Fragments Produced From Multifragmentation Of ^{16}O+^{16}O, M.Y.H. Farag
Alpha Particle Fragments Produced From Multifragmentation Of ^{16}O+^{16}O, M.Y.H. Farag
Turkish Journal of Physics
Angular distribution for alpha particles produced from multifragmentation of ^{16}O + ^{16}O reactions are calculated using the statistical scission model. The alpha particles are sequentially emitted from long lived states of primary fragments populated in these reactions. Eight alpha particles are produced in these reactions. The calculations are carried out for different energies and for different nuclear temperatures. The variances of this multifragmentation process have been numerically calculated. The obtained results are in good agreement with previous calculations.
Interrelation Of Magnetic Properties With The Crystal Structures Of Mefese (Me = Ti; V; Cr; Fe; Co; Ni) Compounds, R. Sadikhov, A. Namazov, J. Guseinov
Interrelation Of Magnetic Properties With The Crystal Structures Of Mefese (Me = Ti; V; Cr; Fe; Co; Ni) Compounds, R. Sadikhov, A. Namazov, J. Guseinov
Turkish Journal of Physics
Magnetization of MeFe$_2$Se$_4$ (Me = Ti; V; Cr; Fe; Co; Ni) compounds at low temperatures has been investigated. It is shown that these compounds are ferrimagnetics with low values of specific magnetization. It is established that along the crystal axis $c$ of a given compound, there have been carried out two types of exchange interactions; cation-cation and cation-anion-cation with different dependence of their quantity on interatomic distance.
The Effect Of Halogen Impurities On Electrocunductivity Of Chalcogenide Glass Semicunductor Se-As System, A.I. Isaogli, S.M. Ibrahimgizi, A.R. Kamilogli
The Effect Of Halogen Impurities On Electrocunductivity Of Chalcogenide Glass Semicunductor Se-As System, A.I. Isaogli, S.M. Ibrahimgizi, A.R. Kamilogli
Turkish Journal of Physics
DC conductivity has been measured as function of dopant concentration for Se-As glass containing 2-10 \% As, doped with Cl or Br. It was established that concentration dependences of the conductivity have maxima for concentration of Cl or Br between $10^{-3}$ and $10^{-2}$ at \%. The effect of halogen impurities on electroconductivity of Se-As glasses has been attributed to the change of relative concentrations of the charged defect centers $(C^-_1, C^+_3)$ and to the occurrence of new $Cl^-, Br^-$ centers associated with chlorine (bromine) atoms and the compensation of the effect of arsenic on the energy spectrum of electron states.
Shallow Donors In A Quantum Well Wire; Electric Field And Geometrical Effects, M. Ulaş, H. Akbaş, M. Tomak
Shallow Donors In A Quantum Well Wire; Electric Field And Geometrical Effects, M. Ulaş, H. Akbaş, M. Tomak
Turkish Journal of Physics
Subband and shallow donor binding energies are calculated. The emphasis is given on the electric field effects for wires of different shapes. It is shown that the donor binding energy is sensitive to the interplay of the electric field and geometrical effects.
\Tau->\Rho\Nu Decay And Leptonic Decay Constants Of Vector Mesons, Kh. Ablakulov, B.N. Kuranov, T.Z. Nasyrov
\Tau->\Rho\Nu Decay And Leptonic Decay Constants Of Vector Mesons, Kh. Ablakulov, B.N. Kuranov, T.Z. Nasyrov
Turkish Journal of Physics
The new Salpeter equation for vector mesons is proposed and the representation for their leptonic decay constants is obtained.
Resonance Production Of New Resonances At Ep And \Gamma P Colliders, A. Çeli̇kel And M. Kantar
Resonance Production Of New Resonances At Ep And \Gamma P Colliders, A. Çeli̇kel And M. Kantar
Turkish Journal of Physics
We study the resonance production of new particles predicted by preonic models at Linac-Ring type $ep$ and $\gamma p$ colliders. It is shown that these machines will allow to investigate the new particles with masses up to few TeV scale.
Determination Of Temperature Dependent Frequency Factor Constant From Tl Glow Curves, A. Necmeddin Yazici
Determination Of Temperature Dependent Frequency Factor Constant From Tl Glow Curves, A. Necmeddin Yazici
Turkish Journal of Physics
A new method solely based on the theoretical and experimental analysis of thermoluminescence glow curves is proposed for the determination of the temperature dependent frequency factor constant.
Eects Of Post Deposition Treatments On Vacuum Evaporated Cdte Thin Films And Cds=Cdte Heterojunction Devices, Habibe Bayhan, Çiğdem Erçelebi̇
Eects Of Post Deposition Treatments On Vacuum Evaporated Cdte Thin Films And Cds=Cdte Heterojunction Devices, Habibe Bayhan, Çiğdem Erçelebi̇
Turkish Journal of Physics
$CdTe, CdS$ thin films and $n-CdS/p-CdTe$ heterostructures have been prepared by conventional vacuum evaporation technique. Some post deposition treatments to optimize the device efficiency have been analyzed and the effects of the individual process steps on the material and device properties were investigated. Annealing in air with and without $CdCl_2$-treatment decreased the $CdTe$ resistivity. The $CdCl_2$-dip followed by annealing in air at $300^{\circ}C$ for 5 min improved the grain size and polycrystalline nature of $CdTe$ thin films. Solar efficiency improvements were achieved when heterojunctions were prepared on successively treated (i.e. etched, air annealed, $CdCl_2$-processed) $CdTe$ surfaces. Etching of the $CdTe$ …