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 7621 - 7650 of 8705

Full-Text Articles in Entire DC Network

Cover And Contents Jan 2008

Cover And Contents

Turkish Journal of Chemistry

No abstract provided.


A Novel Theoretical Procedure To Determine Absorption And Gain Coefficients In A Symmetric Single Step-Index Quantum Well Laser, Mustafa Temi̇z, Özgür Önder Karakilinç, Mehmet Ünal Jan 2008

A Novel Theoretical Procedure To Determine Absorption And Gain Coefficients In A Symmetric Single Step-Index Quantum Well Laser, Mustafa Temi̇z, Özgür Önder Karakilinç, Mehmet Ünal

Turkish Journal of Electrical Engineering and Computer Sciences

If the indices n_{II}, n_{I,III} of the regions, the thickness 2a of the active region (AR) and the wavelength \lambda for a single symmetric step-index quantum well laser (SSSIQWL) are given, the normalized propagation constant (NPC) \alpha is obtained. In this novel method, absorption and gain coefficients for the SSSIQWL have been obtained in terms of the NPCs \alpha in the even and odd fields, directly.


Evolutionary Algorithms For The Unit Commitment Problem, A. Şi̇ma Uyar, Belgi̇n Türkay Jan 2008

Evolutionary Algorithms For The Unit Commitment Problem, A. Şi̇ma Uyar, Belgi̇n Türkay

Turkish Journal of Electrical Engineering and Computer Sciences

This paper compares three evolutionary computation techniques, namely Steady-State Genetic Algorithms, Evolutionary Strategies and Differential Evolution for the Unit Commitment Problem. The comparison is based on a set of experiments conducted on benchmark datasets as well as on real-world data obtained from the Turkish Interconnected Power System. The results of two state-of-the-art evolutionary approaches, namely a Generational Genetic Algorithm and a Memetic Algorithm for the same benchmark datasets are also included in the paper for comparison. The tests show that Differential Evolution is the best performer among all approaches on the test data used in the paper. The performances of …


Post-Miocene Deformation In The South Of The Galatean Volcanic Province, Nw Of Central Anatolia (Turkey), Bora Rojay, A. Karaca Jan 2008

Post-Miocene Deformation In The South Of The Galatean Volcanic Province, Nw Of Central Anatolia (Turkey), Bora Rojay, A. Karaca

Turkish Journal of Earth Sciences

Central Anatolia, located on the immense Alpine-Himalayan orogenic belt, has a complicated neotectonic evolution, and NE-SW-trending Neogene horsts-graben systems that rejuvenate pre-existing palaeostructures are among the most important structures which help us understand the tectonic evolution of Central Anatolia. Post-Miocene deformational studies were carried out in Miocene-Quaternary sequences situated at the southeastern margin of the Galatean Volcanic Province (NW of Central Anatolia, Turkey) in order to understand the deformational history of Central Anatolia. The structural analyses were based on bedding attitude data and fault plane slip data. Fold analysis in Miocene units gave an asymmetrical fold axis trending 046ºN. Although …


Punctuated Exhumation And Foreland Basin Formation And Infilling In (Circum)-Central Anatolia (Turkey) Associated With The Neo-Tethyan Closure, Durmuş Boztuğ, Haluk Temi̇z, Raymond Jonckheere, Lothar Ratscbacher Jan 2008

Punctuated Exhumation And Foreland Basin Formation And Infilling In (Circum)-Central Anatolia (Turkey) Associated With The Neo-Tethyan Closure, Durmuş Boztuğ, Haluk Temi̇z, Raymond Jonckheere, Lothar Ratscbacher

Turkish Journal of Earth Sciences

Apatite fission-track data indicate that the (circum)-central Anatolian granitoids (CAG) were exhumed during successive shortening phases following continent-continent collisions within the Neo-Tethyan domain in central and east-central Anatolia. The Early to Middle Paleocene exhumation of the CAG is thought to be a consequence of the collision between the Tauride-Anatolide platform (TAP) and the Eurasian plate (EP) following the consumption of the İzmir-Ankara-Erzincan strand of the northern Neo-Tethys. The Oligocene exhumation documented by the data for the Kösedağ pluton in east-central Anatolia is considered to be related to the compression due to continuing convergence between the EP and TAP which seems …


Textural And Compositional Evidence For Magma Mixing In The Evolution Of The Çamlıdere Volcanic Rocks (Galatean Volcanic Province), Central Anatolia, Turkey, Eli̇f Varol, Abi̇di̇n Temel, Alain Gourgaud Jan 2008

Textural And Compositional Evidence For Magma Mixing In The Evolution Of The Çamlıdere Volcanic Rocks (Galatean Volcanic Province), Central Anatolia, Turkey, Eli̇f Varol, Abi̇di̇n Temel, Alain Gourgaud

Turkish Journal of Earth Sciences

The Çamlıdere area, in the Galatean Volcanic Province (Ankara), Turkey, is composed of rhyolitic, andesitic, trachytic, dacitic and locally basaltic rocks. The older volcanic rocks in the studied area are rhyolitic and the younger ones basaltic. The phenocrysts from all the volcanic rocks exhibit some petrographic disequilibrium features such as: (a) coexistence of reversely, normally and oscillatory zoned sieved or unsieved plagioclase in the same rock; (b) wide compositional variation of An% in feldspar phenocrysts; (c) sieved, unsieved, normally and reversely zoned pyroxenes occur together in a single rock; (d) some orthopyroxene phenocrysts are surrounded by clinopyroxene; (e) reaction textures, …


Cover And Contents Jan 2008

Cover And Contents

Turkish Journal of Earth Sciences

No abstract provided.


Cover And Contents Jan 2008

Cover And Contents

Turkish Journal of Physics

No abstract provided.


Calculated Pressure Induced Bcc-Fcc Phase Transitions In Alkali Metals, Hamdi̇ Dağistanli, Riza Haluk Mutlu Jan 2008

Calculated Pressure Induced Bcc-Fcc Phase Transitions In Alkali Metals, Hamdi̇ Dağistanli, Riza Haluk Mutlu

Turkish Journal of Physics

The partial occupation numbers and density of states (DOS), and the total DOS at the Fermi level are calculated as a function of reduced atomic volume for bcc and fcc alkali metals employing the linear-muffin-tin-orbital (LMTO) method. By means of the abrupt changes obtained in the partial and total DOS values at the Fermi level, good agreement with regard to experiment were found in predicting the bcc-fcc transition volumes of the alkali metals.


Cover And Contents Jan 2008

Cover And Contents

Turkish Journal of Physics

No abstract provided.


Bioactivities Of The Various Extracts And Essential Oils Of Salvia Limbata C.A.Mey. And Salvia Sclarea L., Hati̇ce Öğütçü, Atalay Sökmen, Münevver Sökmen, Moschos Polissiou, Julia Serkedjieva, Di̇mi̇tra Daferera, Fi̇kretti̇n Şahi̇n, Özlem Bariş, Medi̇ne Güllüce Jan 2008

Bioactivities Of The Various Extracts And Essential Oils Of Salvia Limbata C.A.Mey. And Salvia Sclarea L., Hati̇ce Öğütçü, Atalay Sökmen, Münevver Sökmen, Moschos Polissiou, Julia Serkedjieva, Di̇mi̇tra Daferera, Fi̇kretti̇n Şahi̇n, Özlem Bariş, Medi̇ne Güllüce

Turkish Journal of Biology

The present study evaluated the in vitro antimicrobial, antioxidant, and antiviral activities of the essential oil and various extracts of Salvia limbata C.A.Mey. and Salvia sclarea L., as well as the content of its essential oil. The activities of essential oils were tested against a wide range of human-, plant-, and food-borne microorganisms. A total of 55 microbial organisms belonging to 35 bacteria and 19 fungi and yeast species were tested using disk diffusion, micro dilution, and micro-well dilution. The essential oils were found to possess antimicrobial activity against some of the tested fungi, while no activity was observed against …


Cover And Contents Jan 2008

Cover And Contents

Turkish Journal of Earth Sciences

No abstract provided.


Cover And Contents Jan 2008

Cover And Contents

Turkish Journal of Earth Sciences

No abstract provided.


Platinum-Group Minerals (Pgm) And Other Solid Inclusions In The Elbistan-Kahramanmaraş Mantle-Hosted Ophiolitic Chromitites, South-Eastern Turkey: Their Petrogenetic Significance, İbrahi̇m Uysal Jan 2008

Platinum-Group Minerals (Pgm) And Other Solid Inclusions In The Elbistan-Kahramanmaraş Mantle-Hosted Ophiolitic Chromitites, South-Eastern Turkey: Their Petrogenetic Significance, İbrahi̇m Uysal

Turkish Journal of Earth Sciences

The Elbistan-Kahramanmaraş podiform ophiolitic chromitites, in southeastern Turkey, contain abundant primary inclusions of platinum-group minerals (PGM), base-metals sulphides (BMS) and silicates. These inclusions are very small, generally less than 15 microns in size, and mostly occur in chromian spinel. The following PGM have been recognized: laurite, iridium, irarsite, ruarsite and several unidentified PGE phases. Millerite, pentlandite, bornite, digenite, chalcopyrite and betekhtinite are the BMS that have been identified. Mg-rich hornblende, accompanied by rare olivine, clinopyroxene and phlogopite, are the most abundant silicate inclusions. Most of the PGM, BMS and silicate inclusions are considered primary, i.e. formed during the high temperature …


The Biology, Nymphal Stages, And Life Habits Of The Endemic Sand Dune Cricket Schizodactylus Inexpectatus (Werner, 1901) (Orthoptera: Schizodactylidae), Gökhan Aydin, Andrey Khomutov Jan 2008

The Biology, Nymphal Stages, And Life Habits Of The Endemic Sand Dune Cricket Schizodactylus Inexpectatus (Werner, 1901) (Orthoptera: Schizodactylidae), Gökhan Aydin, Andrey Khomutov

Turkish Journal of Zoology

The biology, nymphal stages, and life habits of the endemic dune cricket Schizodactylus inexpectatus (Werner, 1901) (Orthoptera: Schizodactylidae) were investigated in this study carried out between 2000 and 2007 in the Çukurova delta (Adana province) and in Alata (Mersin province), Turkey. The study showed that S. inexpectatus, which is a nocturnal insect, passes through 9 nymphal stages, each characterised by its own body size. The present study showed that certain properties of burrows, such as their depths, do not depend on either adult or immature stages of the insect. Food preferences of cannibalistic species of S. inexpectatus were also investigated …


Clinical And Rhinoscintigraphic Evaluation Of Oral Macrolides In The Management Of Sinonasal Polyposis, Emi̇ne Aydin, Hülya Ortapamuk, Hakan Korkmaz, Engi̇n Dursun, Adi̇l Eryilmaz, Güleser Saylam, Muharrem Dağli Jan 2008

Clinical And Rhinoscintigraphic Evaluation Of Oral Macrolides In The Management Of Sinonasal Polyposis, Emi̇ne Aydin, Hülya Ortapamuk, Hakan Korkmaz, Engi̇n Dursun, Adi̇l Eryilmaz, Güleser Saylam, Muharrem Dağli

Turkish Journal of Medical Sciences

Aim: To document the efficacy of low-dose long-term oral macrolide treatment in the management of sinonasal polyposis. The study was designed prospectively in a group of patients with sinonasal polyposis and negative history of surgery. Materials and Methods: Ten patients were administered roxithromycin (RXM) 150 mg/day single oral dose for eight weeks. All patients underwent Tc-99m rhinoscintigraphic evaluation of mucociliary activity and endoscopic evaluation before and after the treatments. Response to treatment, in terms of rhinoscintigraphic and endoscopic improvement, was assessed. Results: Of the 10 patients, 7 were male and 3 female, with an average age of 46 years (27-74). …


Dermatomyositis Associated With Hemophagocytic Syndrome: A Case Report/Review Of The Literature, Engi̇n Sennaroğlu, Berçem Ayçi̇çek Doğan, Hasan Tunca, Bariş Yilmaz, Gamze Gedi̇k, Burak Ci̇velek, Si̇nem Tümtürk Jan 2008

Dermatomyositis Associated With Hemophagocytic Syndrome: A Case Report/Review Of The Literature, Engi̇n Sennaroğlu, Berçem Ayçi̇çek Doğan, Hasan Tunca, Bariş Yilmaz, Gamze Gedi̇k, Burak Ci̇velek, Si̇nem Tümtürk

Turkish Journal of Medical Sciences

Hemophagocytic syndrome (HPS) is a disorder that might be transferred genetically due to an autosomal recessive genetic defect of the long arm of chromosome 9 and chromosome 10 (9q21.3-22 and 10q21-22), termed as primary hemophagocytic syndrome (PHPS) or familial hemophagocytic hemophagocytosis (FHPS) and it may be associated with a variety of infections, malignant neoplasms, drugs, autoimmune diseases and various immuno deficiencies, termed as secondary hemophagocytic syndrome (SHPS). For most patients with HPS, the outcome is rapid and fatal unless the diagnosis is made early and followed by prompt therapeutic intervention. Fever, hepatosplenomegaly, cytopenia, hypertriglyceridemia and/or hypofibrinogenemia, low erythrocyte sedimentation rate, …


Cover And Contents Jan 2008

Cover And Contents

Turkish Journal of Agriculture and Forestry

No abstract provided.


Cover And Contents Jan 2008

Cover And Contents

Turkish Journal of Biology

No abstract provided.


Cover And Contents Jan 2008

Cover And Contents

Turkish Journal of Biology

No abstract provided.


Cover And Contents Jan 2008

Cover And Contents

Turkish Journal of Biology

No abstract provided.


Cover And Contents Jan 2008

Cover And Contents

Turkish Journal of Biology

No abstract provided.


Cover And Contents Jan 2008

Cover And Contents

Turkish Journal of Biology

No abstract provided.


Cover And Contents Jan 2008

Cover And Contents

Turkish Journal of Earth Sciences

No abstract provided.


On The Origin And Age Of The Arıburnu Beachrock, Gelibolu Peninsula, Turkey, Ahmet Evren Ergi̇nal, Nafi̇ye Kiyak Güneç, Mustafa Bozcu, Ahmet Ertek, Hakan Güngüneş, Ali̇ Sungur, Gülen Türker Jan 2008

On The Origin And Age Of The Arıburnu Beachrock, Gelibolu Peninsula, Turkey, Ahmet Evren Ergi̇nal, Nafi̇ye Kiyak Güneç, Mustafa Bozcu, Ahmet Ertek, Hakan Güngüneş, Ali̇ Sungur, Gülen Türker

Turkish Journal of Earth Sciences

The beachrock formation on the Arıburnu coast situated in the Gelibolu Peninsula has been studied by field observation, thin-section interpretation, physicochemical analyses including ICP-AES and SEM/EDS, and OSL dating. These analyses reveal the presence of different amounts of major (Si, Ca, Mg, K, Fe, Al and Na) and trace elements within the beachrock cement with Si (36.2%) and Ca (32.68%) dominating the overall composition. Beachrocks composed of highly-fractured and friable beds reach a total thickness of 80 cm extending from +60 cm at the uppermost level down to -1 m at their most seaward extent and grade from conglomerate to …


Investigation Of The Antimutagenic Potentials Of The Methanol Extract Of Origanum Vulgare L. Subsp. Vulgare In The Eastern Anatolia Region Of Turkey, Tüli̇n Özbek, Medi̇ne Güllüce, Fi̇kretti̇n Şahi̇n, Hakan Özkan, Sevgi̇ Sevsay, Özlem Bariş Jan 2008

Investigation Of The Antimutagenic Potentials Of The Methanol Extract Of Origanum Vulgare L. Subsp. Vulgare In The Eastern Anatolia Region Of Turkey, Tüli̇n Özbek, Medi̇ne Güllüce, Fi̇kretti̇n Şahi̇n, Hakan Özkan, Sevgi̇ Sevsay, Özlem Bariş

Turkish Journal of Biology

The aim of this study was to evaluate the antimutagenic activity of the methanol extract of Origanum vulgare L. subsp. vulgare. Antimutagenic activity was estimated by employing the plate incorporation AMES/Salmonella histidine reversion assay. The base pair substitution tester strain Salmonella typhimurium TA1535 and the frame shift mutagen strain S. typhimurium TA1538 were used against direct acting mutagens - sodium azide (NaN_3), 4-nitro-1-quinoline oxide (4NQO) and the S9-dependent mutagen 2-aminofluorene (2AF). The results suggested that in the absence of S9 metabolic activation, all 3 doses (5, 0.5, and 0.05 \mug/plate) of the plant extract tested caused statistically significant (P < 0.05) antimutagenic activity on TA1535 strain, but not on TA1538 strain. However, in the presence of S9 microsomal fraction, the plant extract exerted moderate antimutagenic activity against the 2AF mutagen and reduced mutant colonies in TA1535 and TA1538 strains. As a result, the methanol extract of Origanum vulgare subsp. vulgare showed antimutagenic effects at 5, 0.5, and 0.05 \mug/plate concentrations. These effects may be explained with the antioxidant activity mechanism, changes in membrane lipids, and permeability of ion channels.


Cover And Contents Jan 2008

Cover And Contents

Turkish Journal of Biology

No abstract provided.


Biomedical Circuits And Systems Dedicated For Sensing And Neurostimulation: Case Study On Urinary Bladder Dysfunctions, Mohamad Sawan, Aguibou Ba, Faycal Mounaim, Jacques Corcos, Mostafa Elhilali Jan 2008

Biomedical Circuits And Systems Dedicated For Sensing And Neurostimulation: Case Study On Urinary Bladder Dysfunctions, Mohamad Sawan, Aguibou Ba, Faycal Mounaim, Jacques Corcos, Mostafa Elhilali

Turkish Journal of Electrical Engineering and Computer Sciences

This paper covers circuits and systems techniques for the construction of high reliability biosensing and neurostimulation smart medical devices. Such microsystems are dedicated for interconnections through the peripheral neural systems. Case study related to applications such as bladder control is discussed. Available electrical neurostimulation techniques for the rehabilitation of urinary bladder functions do not allow an adequate voiding due to dyssynergia between the bladder and the sphincter. A new implantable stimulator, built with commercially available electronic components, was designed to overcome these difficulties. The proposed system performs two types of stimulations: Selective Stimulation for bladder voiding and Permanent Stimulation to …


Pattern Synthesis With Uniform Circular Arrays For The Reduction Of Wcdma Intercell Interference, Mohammed Al-Husseini, Elias Yaacoub, Karim Y. Kabalan, Ali El-Hajj Jan 2008

Pattern Synthesis With Uniform Circular Arrays For The Reduction Of Wcdma Intercell Interference, Mohammed Al-Husseini, Elias Yaacoub, Karim Y. Kabalan, Ali El-Hajj

Turkish Journal of Electrical Engineering and Computer Sciences

The deployment of advanced antenna arrays at the base stations of cellular systems is a key technique in reducing intercell interference, and thus increasing the number of served users. Uniform circular arrays (UCAs) provide 360 degrees of coverage, their patterns are steering-invariant and their sidelobe levels are controllable. This paper investigates the use of UCAs having specially synthesized patterns at the base stations of WCDMA cellular systems. The decrease in the ratio of intercell interference to intracell power resulting from the use of these arrays in a beam-steering scheme will be assessed, and the advantages and disadvantages of each pattern …


Distance Relaying Algorithm For Double-Circuit Transmission Line With Compensation For Reactance Effect Under Standard Availability Of Measurements, Jan Izykowski, Marcin Bozek Jan 2008

Distance Relaying Algorithm For Double-Circuit Transmission Line With Compensation For Reactance Effect Under Standard Availability Of Measurements, Jan Izykowski, Marcin Bozek

Turkish Journal of Electrical Engineering and Computer Sciences

This paper deals with non-pilot distance protection of a double-circuit transmission line. Negative impact of the reactance effect, appearing in measuring a fault loop impedance, on operation of the relay is discussed. An adaptive algorithm allowing one to prevent the relay from mis- or mal-operation caused by the reactance effect is introduced. The algorithm is designed for a standard availability of measurements from one end of the double-circuit line, i.e. when three-phase voltage and current from the faulted line circuit, and additionally zero-sequence current from the healthy line circuit, are provided as the relay input signals. The algorithm is based …