Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

TÜBİTAK

Discipline
Keyword
Publication Year
Publication

Articles 17461 - 17490 of 18793

Full-Text Articles in Entire DC Network

Cover And Contents Jan 2010

Cover And Contents

Turkish Journal of Chemistry

No abstract provided.


Quantum Chemical Studies On Tautomerism And Basicity Behavior Of Some 1,2,4-Triazole Derivatives, Cemi̇l Öğreti̇r, Yadi̇gar Gülseven Sidir, İsa Sidir, Erol Taşal Jan 2010

Quantum Chemical Studies On Tautomerism And Basicity Behavior Of Some 1,2,4-Triazole Derivatives, Cemi̇l Öğreti̇r, Yadi̇gar Gülseven Sidir, İsa Sidir, Erol Taşal

Turkish Journal of Chemistry

The acidity constants, relative stabilities, and tautomeric equilibrium constants of some 1,2,4-triazole derivatives were determined using the density functional theory (DFT) with the B3LYP method and 6-311G(d,p) basis set. The integral equation formalism version of the polarizable continuum model (IEFPCM) was used in the calculations of the aqueous phase. The calculated tautomeric equilibrium and relative stabilities values revealed that the 4H-1,2,4 triazole form for all studied molecules was favored over the 1H-1,2,4 triazole form. Protonation processes indicated the predominance of the 1H-1,2,4 triazole form over the 2H-1,2,4 triazole form. The correlation attempt between the experimental and the calculated acidity constants, …


Cover And Contents Jan 2010

Cover And Contents

Turkish Journal of Chemistry

No abstract provided.


Influence Of The Nitrogen Concentration On The Electrical Characteristic Of Hydrogenated Amorphous Silicon Nitride (A-Sin_X:H) Based Schottky Diodes, İlker Ay, Hüseyi̇n Tolunay Jan 2010

Influence Of The Nitrogen Concentration On The Electrical Characteristic Of Hydrogenated Amorphous Silicon Nitride (A-Sin_X:H) Based Schottky Diodes, İlker Ay, Hüseyi̇n Tolunay

Turkish Journal of Physics

In this study, the Schottky diode characteristic of hydrogenated amorphous silicon nitride (a-SiN_x:H) samples containing various amounts of nitrogen have been investigated via both I-V and C-V measurements. From forward bias I-V measurements in the dark, the barrier height of samples (\phi_{B0}), ideality factor (\eta ), modified Richardson constant (A^\ast) and series resistances (R_s) have been obtained as the function of temperature for different nitrogen content. In addition, forward and reverse bias current ratios (I_f/I_r) at V~=~1 volt have been investigated as the function of temperature for different nitrogen content. Light sensitivity of the samples has also been investigated under …


Structure And Optical Properties Of Cuals_2 Thin Films Prepared Via Chemical Bath Deposition, Tariq Alwan, Mushtak Jabbar Jan 2010

Structure And Optical Properties Of Cuals_2 Thin Films Prepared Via Chemical Bath Deposition, Tariq Alwan, Mushtak Jabbar

Turkish Journal of Physics

CuAlS_2 thin films of thicknesses 118 \pm 5 nm were deposited on glass substrates using chemical bath deposition technique. The details of the preparation method are well described. The method is relatively simple and is easily controlled and sufficient to produce large area and good adherence to the substrate films. Effect of annealing temperature T_a on the structure, and optical properties of CuAlS_2 films were investigated. The structures of the films were studied by X-ray diffraction and FTIR spectrophotometer. The optical properties of the films were ascertained by UV-VIS spectrophotometer (wavelengths ranging between 300 and 900 nm). The optical transmittance …


Cover And Contents Jan 2010

Cover And Contents

Turkish Journal of Physics

No abstract provided.


Linear-Like Discrete-Time Fuzzy Control In The Regulation Of Irrigation Canals, Ömer Faruk Durdu Jan 2010

Linear-Like Discrete-Time Fuzzy Control In The Regulation Of Irrigation Canals, Ömer Faruk Durdu

Turkish Journal of Agriculture and Forestry

A linear-like discrete-time fuzzy controller was designed to control and stabilize a single-pool irrigation canal. Saint Venant equations for open-channel flow were linearized using the Taylor series and a finite-difference approximation of the original nonlinear partial differential equations. Using the linear optimal control theory, a traditional linear quadratic regulator (LQR) was first developed for an irrigation canal with a single-pool, and the results were observed. Then a linear-like global system representation of a discrete-time fuzzy system was proposed by viewing a discrete-time fuzzy system in a global concept and unifying the individual matrices into synthetic matrices. This linear-like representation aided …


Evaluation Of Fertilizing Schemes For Direct-Seeding Rice Fields In Taihu Lake Basin, China, Yong Li, Lin Zhang Yang, Chao Wang Jan 2010

Evaluation Of Fertilizing Schemes For Direct-Seeding Rice Fields In Taihu Lake Basin, China, Yong Li, Lin Zhang Yang, Chao Wang

Turkish Journal of Agriculture and Forestry

Field experiments were performed to identify an effective fertilizing scheme for direct-seeding rice (DSR) fields in the Taihu Lake Basin in east China. Based on local traditions, 3 typical fertilizing schemes (FS-1, FS-2, and FS-3) were evaluated, in consideration of ensuring a certain rice yield and relatively low nitrogen (N) loss. The base, seedling, tillering, jointing, and panicle fertilizers for FS-1 were all 20% of 270 kg N ha^{-1}, those for FS-2 were 30%, 30%, 0%, 25%, and 15% of 270 kg N ha^{-1}, and 15%, 20%, 25%, 20%, and 20% of 220 kg N ha^{-1} for FS-3, respectively. The …


Cover And Contents Jan 2010

Cover And Contents

Turkish Journal of Agriculture and Forestry

No abstract provided.


Organic Materials: Sources Of Nitrogen In The Organic Production Of Lettuce, Maja Manojlovic, Ranko Cabilovski, Martina Bavec Jan 2010

Organic Materials: Sources Of Nitrogen In The Organic Production Of Lettuce, Maja Manojlovic, Ranko Cabilovski, Martina Bavec

Turkish Journal of Agriculture and Forestry

This paper presents the results of 2 experiments: an incubation experiment and a subsequent field experiment. An incubation experiment was set up in order to determine the mineralization potential of different organic materials (OMs) (well-rotted farmyard manure [FTM], guano [G], soybean seed [S], and forage pea seed [P]), the kinetics of mineral nitrogen (N) release, and the correlation between OM content and the quantity of mineralized N. The results of the incubation experiment were checked under field conditions in which different OMs were used as N sources for lettuce (Lactuca sativa L.). The highest mineralization rate constant k (0.127 day^{-1}) …


Certain Physical And Mechanical Properties Of Medium Density Fiberboards Manufactured From Blends Of Corn (Zea Mays Indurata Sturt.) Stalks And Pine (Pinus Nigra) Wood, Mehmet Akgül, Cengi̇z Güler, Yalçin Çöpür Jan 2010

Certain Physical And Mechanical Properties Of Medium Density Fiberboards Manufactured From Blends Of Corn (Zea Mays Indurata Sturt.) Stalks And Pine (Pinus Nigra) Wood, Mehmet Akgül, Cengi̇z Güler, Yalçin Çöpür

Turkish Journal of Agriculture and Forestry

Corn stalk is a renewable natural resource that currently has limited industrial utilization. The objective of this study was to examine some chemical properties of corn stalk (holocellulose, \alpha-cellulose, lignin and ash content, alcohol-benzene, hot and cold water solubility, and solubility in dilute alkali [1% NaOH]) and to evaluate its suitability for medium-density fiberboard (MDF) production. Panels were produced using mixtures of corn stalk (Zea mays indurata Sturt.) and pine (Turkish Pinus nigra) fibers in various proportions (from 0% to 100%). The panels produced had density levels of 0.6, 0.7, and 0.8 g cm^{-3}. The physical and mechanical properties of …


Cover And Contents Jan 2010

Cover And Contents

Turkish Journal of Veterinary & Animal Sciences

No abstract provided.


Dominant Aerobic Bacterial Community Of Sea Bass (Dicentrarchus Labrax L.1758) Larvae During Weaning From Artemia To Dry Feed In Culture Conditions, Ayberk Ayaz, Süheyla Karataş Jan 2010

Dominant Aerobic Bacterial Community Of Sea Bass (Dicentrarchus Labrax L.1758) Larvae During Weaning From Artemia To Dry Feed In Culture Conditions, Ayberk Ayaz, Süheyla Karataş

Turkish Journal of Veterinary & Animal Sciences

The aim of this study was to determine the dominant aerobic bacterial community of sea bass larvae during their weaning period in 2 different marine hatcheries in Muğla-Bodrum region. Samplings were made in January, March, and May 2005. Larvae and water samples were diluted in certain ratios and were inoculated to Marine Agar, TCBS Agar, Pseudomonas Agar, King Bee Agar, MRS agar, Blood Agar and Plate Count Agar, in that order. Water temperature, pH, saturation, salinity, and features of the system used were recorded. Isolated bacterial strains were identified with standard biochemical methods and API 20E Rapid Identification Kits. In …


Cover And Contents Jan 2010

Cover And Contents

Turkish Journal of Veterinary & Animal Sciences

No abstract provided.


Signature Splitting And Signature Inversion Of Rotational Bands In Odd-Odd Nuclei In Rare-Earth Region, Manal Mahmoud Sirag Jan 2009

Signature Splitting And Signature Inversion Of Rotational Bands In Odd-Odd Nuclei In Rare-Earth Region, Manal Mahmoud Sirag

Turkish Journal of Physics

Anomalous signature splitting and signature inversion for the configuration \pi h_{11/2} \otimes \nu i_{13/2} in rotational bands of odd-odd nuclei have been studied using the energy staggering index S(I) as a function of spin I. The unfavored signature index was found lying lower than the favored one. A systematic look at the features of this signature inversion in a series of nine lighter rare earth nuclei in the region around A \sim 160 (Z~=~65-75, N~=~89-101) are presented. The analysis reveals an anomalous signature splitting for this configuration. The magnitude of signature splitting at low spins decreases as the proton number …


Cover And Contents Jan 2009

Cover And Contents

Turkish Journal of Physics

No abstract provided.


Parental Obesity Compared With Serum Leptin And Serum Leptin Receptor Levels Among Abese Adults In The Gaza Strip, Baker Mahmud Zabut, Naji H. Holi, Yousef I. Aljeesh Jan 2009

Parental Obesity Compared With Serum Leptin And Serum Leptin Receptor Levels Among Abese Adults In The Gaza Strip, Baker Mahmud Zabut, Naji H. Holi, Yousef I. Aljeesh

Turkish Journal of Medical Sciences

Aims: To investigate whether parental obesity influences serum leptin hormone and soluble leptin receptor (Ob-Re) concentrations among obese adults in the Gaza Strip. Materials and methods: A case-control design was used. Sample used was convenient and obtained from 2 largest obesity clinics in the Gaza Strip. It consisted of 83 overweight and obese adults without history of other diseases (case group). Control group consisted of 83 ideal weight adults who were selectively chosen from the same clinics. Self reported structured interviews and serum blood samples were obtained from both groups. Human leptin competitive ELISA kits were used for determination of …


Ornithogalum Nurdaniae (Liliaceae), A New Species From North-West Anatolia, Turkey, Yavuz Bağci, Ahmet Savran, İsa Başköse Jan 2009

Ornithogalum Nurdaniae (Liliaceae), A New Species From North-West Anatolia, Turkey, Yavuz Bağci, Ahmet Savran, İsa Başköse

Turkish Journal of Botany

Ornithogalum nurdaniae Y.Bağcı & Savran sp. nov. (Liliaceae), a new species related to O. oligophyllum E.D.Clarke, is described and illustrated from Uludağ (the Bithynian Olympus), a mountain in NW Anatolia well known for its rich flora and many local endemics (A2 Bursa province). Diagnostic morphological characters are discussed. Notes are also presented on the ecology, biogeography, and conservation status of the new species.


A First Vouchered Wild Record For The Flora Of Turkey: Aegilops Juvenalis (Thell.) Eig (Poaceae), Evren Cabi̇, Musa Doğan Jan 2009

A First Vouchered Wild Record For The Flora Of Turkey: Aegilops Juvenalis (Thell.) Eig (Poaceae), Evren Cabi̇, Musa Doğan

Turkish Journal of Botany

Aegilops juvenalis (Thell.) Eig (Poaceae) is recorded and vouchered for the first time from Turkey. This first vouchered wild record is confined to Ceylanpınar province in C8 Şanlıurfa. The diagnostic morphological characters discriminating it from of Aegilops crassa Boiss. are pointed out. Notes are presented on its ecology and phenology. A distribution map of this species is also given.


Analytical Regularization Method For Electromagnetic Wave Diffraction By Axially Symmetrical Thin Annular Strips, Fati̇h Di̇kmen, Yury Alexanderovich Tuchkin Jan 2009

Analytical Regularization Method For Electromagnetic Wave Diffraction By Axially Symmetrical Thin Annular Strips, Fati̇h Di̇kmen, Yury Alexanderovich Tuchkin

Turkish Journal of Electrical Engineering and Computer Sciences

A new mathematically rigorous and numerically efficient method based on the combination of Orthogonal Polynomials Method, and Analytical Regularization Method, for electromagnetic wave diffraction by a model structure for various antennae such as Fresnel zone plates is proposed. It can be used as validation tool for the other (more general or less accurate) numerical methods and physical approaches. The initial boundary value problem is equivalently reduced to the infinite system of the linear algebraic equations of the second kind, i.e. to an equation of the type (I+H) x=b in the space l_2 with compact operator H. This equation can be …


Lichens And Lichenicolous Fungi Of Kızıldağ (Derebucak, Konya), Mustafa Kocakaya, Mehmet Gökhan Halici, Ahmet Aksoy Jan 2009

Lichens And Lichenicolous Fungi Of Kızıldağ (Derebucak, Konya), Mustafa Kocakaya, Mehmet Gökhan Halici, Ahmet Aksoy

Turkish Journal of Botany

Herein 152 taxa of lichens and lichenicolous fungi belonging to 68 genera are reported from Kızıldağ (Derebucak district, Konya province). Of these, 149 taxa are reported from the study area for the first time and 96 taxa are new for Konya province. Lecanora perpruinosa Fröberg and Toninia submexicana de Lesd. are new records for Turkey and Asia.


Cdm Based Controller Design For Nonlinear Heat Exchanger Process, Erkan İmal Jan 2009

Cdm Based Controller Design For Nonlinear Heat Exchanger Process, Erkan İmal

Turkish Journal of Electrical Engineering and Computer Sciences

Most processes are nonlinear, and their control is a difficult yet important problem. The heat exchanger is an example onesuch nonlinear process. In the present paper, the effect of process nonlinearity on the performance of set point tracking and disturbance rejection in two controller methods is investigated. Initially, afirst order plus dead time (FOPDT) model of the process is obtainedvia a software known as Loop-Pro Trainer. Then, the PI-controller tuning values are computed using the internal model control (IMC) correlations based on truncated (first-order) Taylor series approximation. Next, another controller is designed using the coefficient diagram method (CDM). Finally, the …


Emc Education At The University Of Technology Zurich, Gökhan Apaydin, Ni̇yazi̇ Ari Jan 2009

Emc Education At The University Of Technology Zurich, Gökhan Apaydin, Ni̇yazi̇ Ari

Turkish Journal of Electrical Engineering and Computer Sciences

This paper illustrates educational issues in electromagnetic compatibility (EMC) engineering in Switzerland and presents the contents of courses and practical materials for EMC education at the University of Technology Zurich. After giving the fundamentals of theoretical part, practical applications have been given to make students and engineers aware of EMC issues and its problems.


Electromagnetic Compatibility Engineering Education: Problems, Challenges And Perspectives, Levent Sevgi̇ Jan 2009

Electromagnetic Compatibility Engineering Education: Problems, Challenges And Perspectives, Levent Sevgi̇

Turkish Journal of Electrical Engineering and Computer Sciences

Education and training problems and challenges in EMC Engineering are discussed. The necessity of physics-based modeling (theory) and hands-on training (practice) are emphasized. An introductory level EMC lecture and a short course outline are given for modern EMC education.


Vlsi-Cell Placement Technique For Architecture Of Field Programmable Gate Array (Fpga) Design, Avnesh Verma, Sunil Dhingra, M. K. Soni Jan 2009

Vlsi-Cell Placement Technique For Architecture Of Field Programmable Gate Array (Fpga) Design, Avnesh Verma, Sunil Dhingra, M. K. Soni

Turkish Journal of Electrical Engineering and Computer Sciences

The Field Programmable Gate Array (FPGA) is an on field programmable device which can be designed for different applications. Various types of software are available for its synthesis. The cell placement depends upon the designing and programming languages used for FPGA. In this paper cell placement technique of FPGA architecture is analyzed for the application of Space Vector Pulse Width Modulation (SVPWM) technique used in speed control of an induction motor. The modulation pulses are produced due to the various components activated and their interconnection in Configurable Logic Blocks (CLBs). Few of its components are so analyzed to find out …


Cover And Contents Jan 2009

Cover And Contents

Turkish Journal of Electrical Engineering and Computer Sciences

No abstract provided.


Lebesgue-Stieltjes Measure On Time Scales, Asli Deni̇z, Ünal Ufuktepe Jan 2009

Lebesgue-Stieltjes Measure On Time Scales, Asli Deni̇z, Ünal Ufuktepe

Turkish Journal of Mathematics

The theory of time scales was introduced by Stefan Hilger in his Ph. D. thesis in 1988, supervised by Bernd Auldbach, in order to unify continuous and discrete analysis [5]. Measure theory on time scales was first constructed by Guseinov [4], then further studies were made by Guseinov-Bohner [1], Cabada-Vivero [2] and Rzezuchowski [6]. In this article, we adapt the concept of Lebesgue-Stieltjes measure to time scales. We define Lebesgue-Stieltjes \Delta and \nabla-measures and by using these measures, we define an integral adapted to time scales, specifically Lebesgue-Stieltjes \Delta-integral. We also establish the relation between Lebesgue-Stieltjes measure and Lebesgue-Stieltjes \Delta-measure, …


Strong Convergence Theorems By An Extragradient Method For Solving Variational Inequalities And Equilibrium Problems In A Hilbert Space, Poom Kumam Jan 2009

Strong Convergence Theorems By An Extragradient Method For Solving Variational Inequalities And Equilibrium Problems In A Hilbert Space, Poom Kumam

Turkish Journal of Mathematics

In this paper, we introduce an iterative process for finding the common element of the set of fixed points of a nonexpansive mapping, the set of solutions of an equilibrium problem and the set of solutions of the variational inequality for monotone, Lipschitz-continuous mappings. The iterative process is based on the so-called extragradient method. We show that the sequence converges strongly to a common element of the above three sets under some parametric controlling conditions. This main theorem extends a recent result of Yao, Liou and Yao [Y. Yao, Y. C. Liou and J.-C. Yao, ''An Extragradient Method for Fixed …


Cover And Contents Jan 2009

Cover And Contents

Turkish Journal of Mathematics

No abstract provided.


On Symmetric Monomial Curves In P^3, Mesut Şahi̇n Jan 2009

On Symmetric Monomial Curves In P^3, Mesut Şahi̇n

Turkish Journal of Mathematics

In this paper, we give an elementary proof of the fact that symmetric arithmetically Cohen-Macaulay monomial curves are set-theoretic complete intersections. The proof is constructive and provides the equations of the surfaces cutting out the monomial curve.