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Articles 1 - 30 of 800
Full-Text Articles in Physical Sciences and Mathematics
Geochronological And Geochemical Constraints And Origin Of The Tavşanlı Zoneplutonic Rocks (Nw Turkey), Meti̇n Bağci, Mehmet Demi̇rbi̇lek, Nurdane İlbeyli̇, Ahmet Yildiz, Yaşar Ki̇bi̇ci̇
Geochronological And Geochemical Constraints And Origin Of The Tavşanlı Zoneplutonic Rocks (Nw Turkey), Meti̇n Bağci, Mehmet Demi̇rbi̇lek, Nurdane İlbeyli̇, Ahmet Yildiz, Yaşar Ki̇bi̇ci̇
Turkish Journal of Earth Sciences
In the Tavşanlı Zone, the Eocene magmatism led to NW-SE trending plutons located just south of the İzmir-Ankara-Erzincan Suture Zone in Turkey. The Middle Eocene-aged Günyüzü Intrusive Complex (Karacaören, Tekören, Dinek, Kadıncık) is one of these plutonic rocks and has metaluminous to peraluminous, medium-K calc-alkaline to shoshonitic and mainly I-type granite characteristics. The plutonic rocks consist of mainly granodiorite and granite, and their mafic microgranular enclaves are widespread in these rocks. Mineral assemblages in the host rocks and enclaves also are quite similar (quartz, plagioclase, K-feldspar, biotite, and hornblende), but the latter are more enriched in mafic minerals. The enclaves …
Zircon U-Pb Geochronology, Geochemistry, Sr-Nd Isotopic Compositions, And Tectonomagmatic Implications Of Nay (Ne Iran) Postcollisional Intrusives In The Sabzevar Zone, Alireza Almasi, Mohammad Hassan Karimpour, Reza Arjmandzadeh, José Francisco Santos, Khosrow Ebrahimi Nasrabadi
Zircon U-Pb Geochronology, Geochemistry, Sr-Nd Isotopic Compositions, And Tectonomagmatic Implications Of Nay (Ne Iran) Postcollisional Intrusives In The Sabzevar Zone, Alireza Almasi, Mohammad Hassan Karimpour, Reza Arjmandzadeh, José Francisco Santos, Khosrow Ebrahimi Nasrabadi
Turkish Journal of Earth Sciences
The mafic to felsic intrusive rocks of Nay (IRN) are located in the northeast of the central Iranian block. In this study, we present new major and trace element geochemistry, U-Pb zircon ages, and Sr-Nd isotopic data to discuss the origin of the IRN postcollisional units. The oldest units in the Nay area belong to Paleocene?early Eocene volcanic and pyroclastic series including basalt-andesite, latite, dacite, and tuff. These series are crosscut by subvolcanic and granitoid rocks with lithological composition varying from quartz gabbro to K-feldspar granite. The youngest igneous activity is represented by quartz monzodiorite dikes. Hornblende-biotite quartz monzonite from …
Harmonic Numbers Associated With Inversion Numbers In Terms Of Determinants, Takao Komatsu, Amalia Pizarro-Madariaga
Harmonic Numbers Associated With Inversion Numbers In Terms Of Determinants, Takao Komatsu, Amalia Pizarro-Madariaga
Turkish Journal of Mathematics
It has been known that some numbers, including Bernoulli, Cauchy, and Euler numbers, have such corresponding numbers in terms of determinants of Hessenberg matrices. There exist inversion relations between the original numbers and the corresponding numbers. In this paper, we introduce the numbers related to harmonic numbers in determinants. We also give several of their arithmetical and/or combinatorial properties and applications. These concepts can be generalized in the case of hyperharmonic numbers.
Givetian/Frasnian (Middle/Upper Devonian) Transition In The Eastern Taurides, Turkey, Recep Özkan, Ati̇ke Nazi̇k, Axel Munnecke, Di̇lek Gülnur Demi̇ray, Eberhard Schindler, Tuba Aydin Özbek, Emi̇ne Şeker Zor, İsak Yilmaz, Rainer Brocke, Recep Hayretti̇n Sancay, Volker Wilde, Mehmet Namik Yalçin
Givetian/Frasnian (Middle/Upper Devonian) Transition In The Eastern Taurides, Turkey, Recep Özkan, Ati̇ke Nazi̇k, Axel Munnecke, Di̇lek Gülnur Demi̇ray, Eberhard Schindler, Tuba Aydin Özbek, Emi̇ne Şeker Zor, İsak Yilmaz, Rainer Brocke, Recep Hayretti̇n Sancay, Volker Wilde, Mehmet Namik Yalçin
Turkish Journal of Earth Sciences
Devonian strata, including siliciclastic and carbonate rocks that were deposited in shallow marine to coastal environments, are widely distributed in the eastern Taurides of southern Turkey. To document the regional formation of the Givetian (Middle Devonian)/ Frasnian (Upper Devonian) boundary, a section in the eastern Taurides was studied in high resolution with regard to biostratigraphy, microfacies, sequence stratigraphy, and the global Frasne Event. The integrated biostratigraphic investigation was based on calcareous benthic foraminifers, ostracods, conodonts, and palynomorphs, which provide a biostratigraphic frame that allows to recognize the Givetian/Frasnian boundary. On the basis of the lithological variation in the outcrop as …
New Fossil Wood Descriptions From The Pliocene Of Central Anatolia And The Presence Of Taxodioxylon In Turkey From The Oligocene To Pliocene, Ünal Akkemi̇k
Turkish Journal of Earth Sciences
Recent paleobotanical studies on petrified woods revealed valuable information about the Miocene-period trees of Turkey. The purpose of this study is to present new descriptions from the Pliocene of central Anatolia. The materials were collected from a new fossil site of Pliocene age in the village of Yıprak (Çerkeş, Çankırı, Turkey) in central northern Turkey. With this study, a new fossil genus, Cercioxylon Ü. Akkemik, related to modern Cercis L., and a new fossil species of Cupressinoxylon were described, and a long presence of taxodioid type trees from the late Oligocene to Pliocene of Turkey were discussed. The wood composition …
Petrological Characteristics Of The Middle Eocene Toveireh Pluton (Southwest Of Jandaq, Central Iran): Implications For The Eastern Branch Of The Neo-Tethys Subduction, Masumeh Sargazi, Ghodrat Torabi, Tomoaki Morishita
Petrological Characteristics Of The Middle Eocene Toveireh Pluton (Southwest Of Jandaq, Central Iran): Implications For The Eastern Branch Of The Neo-Tethys Subduction, Masumeh Sargazi, Ghodrat Torabi, Tomoaki Morishita
Turkish Journal of Earth Sciences
The Middle Eocene Toveireh plutonic body is located in the western margin of the Central-East Iranian Microcontinent (CEIM). This plutonic body consists of granodiorite, syenogranite, and monzogranite compositions. Granodiorite is the most predominant rock unit, which is composed of quartz, plagioclase, K-feldspar, hornblende, and biotite main mineral phases. The Toveireh pluton is metaluminous to weakly peraluminous (A/CNK = 0.85-1.04) and shows a calc-alkaline I-type affinity. Primitive mantle-normalized spidergrams show enrichment of large ion lithophile elements (Rb, Ba, Th, U) and light rare earth elements (REEs) (La/YbN = 6.8-8.24), as well as depletion of high-field strength elements (Nb, Ta, Ti, P). …
Perfect Numerical Semigroups, María Ángeles Moreno Frías, Jose Carlos Rosales
Perfect Numerical Semigroups, María Ángeles Moreno Frías, Jose Carlos Rosales
Turkish Journal of Mathematics
A numerical semigroup is perfect if it does not have isolated gaps. In this paper we will order the perfect numerical semigroups with a fixed multiplicity. This ordering allows us to give an algorithm procedure to obtain them. We also study the perfect monoid, which is a subset of $\N$ that can be expressed as an intersection of perfect numerical semigroups, and we present the perfect monoid generated by a subset of $\N$. We give an algorithm to calculate it. We study the perfect closure of a numerical semigroup, as well as the perfect numerical semigroup with maximal embedding dimension, …
Small Benthic Foraminiferal Biostratigraphy And Palaeoecology During The Campanian-Maastrichtian Transition In North-Western Tunisia, Abdellatif Bejaoui, Ezzedine Saïdi, Dalila Zaghbib-Turki
Small Benthic Foraminiferal Biostratigraphy And Palaeoecology During The Campanian-Maastrichtian Transition In North-Western Tunisia, Abdellatif Bejaoui, Ezzedine Saïdi, Dalila Zaghbib-Turki
Turkish Journal of Earth Sciences
Campanian-Maastrichtian (C-M) sediments in the Kalâat Senan area (north-western Tunisia) include rich microfauna. Small benthic foraminifera (SBF) analysis at the Wadi Necham (ON) section reveals significant biostratigraphic and palaeoecological changes during the C-M transition. A progressive evolutionary trend within the Bolivinoides lineage allowed us to establish the late Campanian B. decoratus Interval Range Zone (IRZ) and two successive zones in the early Maastrichtian, namely the B. miliaris IRZ and the B. draco Total Range Zone (TRZ), which span the standard planktonic foraminifera Gansserina gansseri IRZ. Foraminiferal semiquantitative data from the C-M transition interval at the studied section yield high values …
Deep Structure Of Central Menderes Massif: Data From Deep Geothermal Wells, Fatma Gülmez, Emre Damci, Umut Bariş Ülgen, Aral Okay
Deep Structure Of Central Menderes Massif: Data From Deep Geothermal Wells, Fatma Gülmez, Emre Damci, Umut Bariş Ülgen, Aral Okay
Turkish Journal of Earth Sciences
The Menderes Massif is a major Alpide metamorphic complex in western Turkey; it is subdivided into southern, central, and northern submassifs by the east-west trending grabens. The basement of the southern Menderes Massif consists of Neoproterozoic micaschists (Selimiye Formation) intruded by Neoproterozoic granites. The basement is overlain by Permo-Carboniferous phyllite, marble, and quartzite (Göktepe Formation), which pass up into a thick sequence of Mesozoic marbles with emery horizons (Milas Marble). The marbles are overlain by latest Cretaceous recrystallized pelagic limestone and Paleocene metaclastics, which are thrusted over by the Lycian nappes. The metamorphism and deformation of the Phanerozoic sequence of …
Estimating The Location Of A Causative Body From A Self-Potential Anomaly Using 2d And3d Normalized Full Gradient And Euler Deconvolution, Petek Sindirgi, Şenol Özyalin
Estimating The Location Of A Causative Body From A Self-Potential Anomaly Using 2d And3d Normalized Full Gradient And Euler Deconvolution, Petek Sindirgi, Şenol Özyalin
Turkish Journal of Earth Sciences
Changes in the size and depth of sources greatly affect self-potential (SP) anomalies. Therefore, it is important to determine the location of the source accurately. In the present study, applications of the normalized full gradient (NFG) method and Euler deconvolution (EUD) were described to determine the location of the sphere-like SP body as complementary approaches to other optimization algorithms. The NFG and EUD methods were tested on synthetic, noise-free, and noisy anomalies caused by sphere-like models in two-dimensional (2D) and three-dimensional (3D) cases. Subsequently, the methods were applied to real field data. The importance of the present study lies in …
Petrography, Geochemistry, And Provenance Of Jurassic Sandstones From Thesakarya Zone, Nw Turkey, Firat Şengün, Osman Ersi̇n Koralay
Petrography, Geochemistry, And Provenance Of Jurassic Sandstones From Thesakarya Zone, Nw Turkey, Firat Şengün, Osman Ersi̇n Koralay
Turkish Journal of Earth Sciences
The Jurassic sandstones exposed in the western part of the Sakarya Zone are yellowish to brown, moderate to well sorted, medium to coarse-grained, grain-supported, and cemented by calcareous and minor silica. Sandstones are mainly classified as litharenite, subarkose, and arkose according to the relative proportions of quartz, feldspar and rock fragments, and major element ratios. On the SiO2 variation diagram, Na2O and K2O show slight positive correlations, which could reflect abundance of sodic plagioclase and K-feldspar with quartz within high Si-content sandstones. Sandstones generally exhibit slight LREE enrichment with respect to HREEs. The REE plots are characteristic for sedimentary rocks …
Structural Evolution Of The Eastern Anatolian Basins: An Example From Collisional To Postcollisional Tectonic Processes, Turkey, Ali̇ Yilmaz, Hüseyi̇n Yilmaz
Structural Evolution Of The Eastern Anatolian Basins: An Example From Collisional To Postcollisional Tectonic Processes, Turkey, Ali̇ Yilmaz, Hüseyi̇n Yilmaz
Turkish Journal of Earth Sciences
The Eastern Anatolian Basins (EABs) started to develop on a mosaic, made up of forearc deposits of the Eastern Pontide Arc (EPA), continental metamorphic rocks of the Anatolian-Iranian Platform (AIP), and obducted ophiolitic units of the North Anatolian Ophiolitic Belt (NAOB) and Southeastern Anatolian Ophiolitic Belt (SAOB). The basement rocks of the East Anatolian Region represent a continental fragment positioned between the EPA to the north and the Arabian Platform to the south. In appearance, it can be said that there are many different basins in the Eastern Anatolian Region. This paper reports on three of them that were studied …
Graphite In Rocks Of The Popigai Impact Crater: Residual Or Retrograde?, Valentin Afanasiev, Sergey Gromilov, Valeri Sonin, Egor Zhimulev, Aleksei Chepurov
Graphite In Rocks Of The Popigai Impact Crater: Residual Or Retrograde?, Valentin Afanasiev, Sergey Gromilov, Valeri Sonin, Egor Zhimulev, Aleksei Chepurov
Turkish Journal of Earth Sciences
The concentration of diamond-bearing tagamite from the Popigai impact crater produces large amounts of graphite in addition to impact diamonds (1:100, respectively). The question arises of whether this is residual graphite not converted to diamond at the time of the Popigai impact or is a retrograde form resulting from back-conversion of impact diamond to graphite in a high-temperature tagamite melt. Experiments show that graphite from tagamite is a residual phase. Coexistence of lonsdaleite, cubic diamond, and single-crystal graphite within a limited volume may be due to different orientations of the graphite base plane relative to the impact stress direction. Thus, …
Holocene Seismic Activity Of The Priene?Sazlı Fault Revealed By Cosmogenic 36cl,Western Anatolia, Turkey, Nasim Mozafari Amiri, Ökmen Sümer, Dmitry Tikhomirov, Susan Ivy-Ochs, Vasily Alfimov, Christof Vockenhuber, Uğur İnci̇, Hasan Sözbi̇li̇r, Naki̇ Akçar
Holocene Seismic Activity Of The Priene?Sazlı Fault Revealed By Cosmogenic 36cl,Western Anatolia, Turkey, Nasim Mozafari Amiri, Ökmen Sümer, Dmitry Tikhomirov, Susan Ivy-Ochs, Vasily Alfimov, Christof Vockenhuber, Uğur İnci̇, Hasan Sözbi̇li̇r, Naki̇ Akçar
Turkish Journal of Earth Sciences
Fault scarps in carbonates are structures well suited to 36Cl analysis of paleoearthquakes to reconstruct the seismic history using cosmogenic 36Cl. In this study, we measured cosmogenic 36Cl concentrations in 117 samples along one of the active faults in Western Anatolia, the Priene?Sazlı Fault scarp, to reconstruct the age of paleoearthquakes along with their slip amounts, beyond the available historical and instrumental archives. Our results indicate four periods of high seismic activity on the Priene?Sazlı Fault since the early Holocene at 8.1 ± 2.0, 6.0 ± 1.5, 3.7 ± 0.9, and 2.2 ± 0.5 ka, with slips of 3.4 ± …
Mineralogy And Geochemistry Of Feed Coals And Combustion Residues Of The Kangal Power Plant (Sivas, Turkey), Ali̇ İhsan Karayi̇ği̇t, Riza Görkem Oskay, Rod A. Gayer
Mineralogy And Geochemistry Of Feed Coals And Combustion Residues Of The Kangal Power Plant (Sivas, Turkey), Ali̇ İhsan Karayi̇ği̇t, Riza Görkem Oskay, Rod A. Gayer
Turkish Journal of Earth Sciences
This study focuses on mineralogical and geochemical compositions of feed coal (FC) and combustion residues, namely fly ash (FA) and bottom ash (BA) samples, obtained from the Kangal coal-fired power plant in central Turkey. The X-ray powder diffraction data indicate that carbonate and clay minerals are dominant phases in the FC samples. In the FA samples, quartz, hematite, anhydrite, lime, and feldspar are generally dominant and abundant phases, whereas calcite, ettringite, and portlandite are generally more abundant in the BA samples. The elements Mo, Cs, and U are significantly enriched in the studied FC, FA, and BA samples. The statistical …
Upper Cretaceous Volcaniclastic Complexes And Calcareous Plankton Biostratigraphy Inthe Western Pontides, Nw Turkey, Katharina Boehm, Michael Wagreich, Erik Wolfgring, Okan Tüysüz, Susanne Gier, İsmai̇l Ömer Yilmaz
Upper Cretaceous Volcaniclastic Complexes And Calcareous Plankton Biostratigraphy Inthe Western Pontides, Nw Turkey, Katharina Boehm, Michael Wagreich, Erik Wolfgring, Okan Tüysüz, Susanne Gier, İsmai̇l Ömer Yilmaz
Turkish Journal of Earth Sciences
This study describes and interprets Upper Cretaceous volcaniclastics interbedded with hemipelagic to pelagic limestones, marls, and turbidites from the Western Pontides, northwestern Turkey. The Dereköy Formation, the Unaz Formation (red pelagic limestone unit), and the Cambu Formation can be distinguished, overlain by the turbiditic Akveren Formation. Biostratigraphic ages from the predominantly volcaniclastic Dereköy Formation indicate Turonian (Dicarinella concavata planktonic foraminifera zone, CC13/UC8-9 nannofossil zones) to middle/late Santonian ages up to CC17/UC13. The Unaz Formation, deposited during the late Santonian (UC13, Dicarinella asymetrica Zone), is overlain by the volcaniclastic Cambu Formation of latest Santonian (CC17b/UC13) to early/middle Campanian (CC20/UC15a) age. However, …
U-Pb Zircon Geochronology, Geochemistry, And Petrogenesis Of The Hamech Intrusions In The Kuh-E-Shah Volcano-Plutonic Complex, Eastern Iran, Abbas Etemadi, Mohammad Hassan Karimpour, Azadeh Malekzadeh Shafaroudi, José Francisco Santos, Ryan Mathur, Sara Ribeiro
U-Pb Zircon Geochronology, Geochemistry, And Petrogenesis Of The Hamech Intrusions In The Kuh-E-Shah Volcano-Plutonic Complex, Eastern Iran, Abbas Etemadi, Mohammad Hassan Karimpour, Azadeh Malekzadeh Shafaroudi, José Francisco Santos, Ryan Mathur, Sara Ribeiro
Turkish Journal of Earth Sciences
The Hamech area is located in the west of Kuh-e-Shah volcano-plutonic complex, close to the boundary between the Lut Block and Sistan Suture Zone (SSZ), and is composed of monzonite to diorite porphyries and rare gabbro that intruded into older volcanic rocks. U-Pb zircon dating indicates an age of 36.9 ± 1 Ma for gabbro (Late Eocene, Priabonian) and 38.6 ± 0.5 Ma for dacite (Late Eocene, Bartonian). Geochemically, the studied intrusions are dominantly I-type, high-K calc-alkaline, and metaluminous features. Primitive mantle-normalized trace-element spider diagrams of these rocks present enrichment in ion lithophile elements such as Cs, Rb, Ba, K, …
Petrology, Geothermobarometry, And P-T Path Of Spinel-Bearing Symplectite Migmatitesfrom The Simin Area, Hamedan, Sanandaj-Sirjan Zone, Iran, Ali Akbar Baharifar, Donna L. Whitney, Kwan-Nang Pang, Sun-Lin Chung, Yoshiyuki Iizuka
Petrology, Geothermobarometry, And P-T Path Of Spinel-Bearing Symplectite Migmatitesfrom The Simin Area, Hamedan, Sanandaj-Sirjan Zone, Iran, Ali Akbar Baharifar, Donna L. Whitney, Kwan-Nang Pang, Sun-Lin Chung, Yoshiyuki Iizuka
Turkish Journal of Earth Sciences
Migmatitic rocks in the Hamedan area, Sanandaj-Sirjan Zone, Iran, contain symplectite that has partially replaced andalusite. In metatexite, symplectite typically consists of spinel + cordierite + Ca-rich plagioclase ± orthoamphibole, but in diatexite, symplectite consists of spinel + Ca-rich plagioclase; cordierite is typically absent from symplectite although it is present in the matrix of the rock. A calculated P-T pseudosection for an average, nonmigmatitic bulk-rock composition indicates that the whole-rock composition was not the effective bulk composition during the formation of symplectite. Therefore, effective bulk compositions (EBCs) were calculated using modal abundance and the average composition of minerals in contact …
Microborings As Indication Of Cryptic Life Modes In The Foraminifer Orbitoides:Maastrichtian Sediments Of The Haymana And Nallıhan Districts (Ankara, Turkey), Muhi̇tti̇n Görmüş, Huri̇ye Demi̇rcan, Yusuf Kağan Kadioğlu, Fuzuli̇ Yağmurlu, Muhammed Sami̇ Us
Microborings As Indication Of Cryptic Life Modes In The Foraminifer Orbitoides:Maastrichtian Sediments Of The Haymana And Nallıhan Districts (Ankara, Turkey), Muhi̇tti̇n Görmüş, Huri̇ye Demi̇rcan, Yusuf Kağan Kadioğlu, Fuzuli̇ Yağmurlu, Muhammed Sami̇ Us
Turkish Journal of Earth Sciences
Widespread Maastrichtian siliciclastics and carbonates cropping out in the Haymana (S Ankara) and Nallıhan (NW Ankara) districts in the northwest and central Anatolia basins include rich Orbitoides occurrences. Microborings in the Orbitoides tests are interesting to notify. In this study, the details of their morphologic structures were investigated. Microborings were analyzed in more than 650 equatorial thin sections of the Orbitoides tests and 100 hard rock thin sections. The abundance of microborings increases in the siliciclastics towards the Cretaceous/Palaeogene boundary (K/Pg). They were identified as Maeandropolydora osmaneliensis Nielsen and Görmüş, Maeandropolydora isp. Curvichnus semorbis Nielsen, Oichnus simplex Bromley, Oichnus isp. …
Blue Sky At Midnight - Earthquake Lightning, Neil Whitehead, Ülkü Ulusoy
Blue Sky At Midnight - Earthquake Lightning, Neil Whitehead, Ülkü Ulusoy
Turkish Journal of Earth Sciences
Earthquake light, emerging from the ground as flashes at night (neglecting other more minor forms), usually has a white hemispherical center and blue outer part. The blue resembles daytime blue sky. Its existence is increasingly verified, with about 80 videos on the web to mid-2017. However, the light must be differentiated from power-grid faults, so sound/color/form/length criteria were developed in this paper through examination of many videos. Light should be coseismic (i.e. when the S-waves arrive), hemispherical, not during a storm, less than 1 s long, without fire or smoke, and without many rapid color changes. Warnings about camera artifacts …
Mineralogy And Geochemistry Of Metalliferous Sedimentary Rocks From The Uppercretaceous Vms Deposits Of The Eastern Pontides (Ne Turkey), Mustafa Kemal Revan, Yurdal Genç, Okan Deli̇baş, Valeri̇y V. Maslennikov, Nuri̇ya R. Ayupova, Okan Zi̇mi̇toğlu
Mineralogy And Geochemistry Of Metalliferous Sedimentary Rocks From The Uppercretaceous Vms Deposits Of The Eastern Pontides (Ne Turkey), Mustafa Kemal Revan, Yurdal Genç, Okan Deli̇baş, Valeri̇y V. Maslennikov, Nuri̇ya R. Ayupova, Okan Zi̇mi̇toğlu
Turkish Journal of Earth Sciences
Metalliferous sedimentary rocks, despite being limited in scope, are important stratigraphic horizons within the volcanogenic massive sulfide (VMS) deposits in the Upper Cretaceous volcanic belt of the Eastern Pontides. The metalliferous sedimentary rocks compose a distinctive genetic class. The abundance of such rocks in the Eastern Pontide district provides a basis for study and description that may be more widely applied in other VMS districts. The metalliferous sedimentary rocks generally form layers less than 1.5 m thick above stratiform massive sulfide ores. The metalliferous sediments are largely composed of quartz and hematite. While the Si ± Fe content of sediments …
Late Quaternary Landscape Evolution Of The Southern Marmara Region:Paleogeographic Implications For Settlements, Nw Turkey, Ni̇zametti̇n Kazanci, Zeynep Ergun, Kaan İren, Suzanne A. Leroy, Sonay Boyraz Aslan, Mehmet Sali̇m Öncel, Koray Koç, Alper Gürbüz
Late Quaternary Landscape Evolution Of The Southern Marmara Region:Paleogeographic Implications For Settlements, Nw Turkey, Ni̇zametti̇n Kazanci, Zeynep Ergun, Kaan İren, Suzanne A. Leroy, Sonay Boyraz Aslan, Mehmet Sali̇m Öncel, Koray Koç, Alper Gürbüz
Turkish Journal of Earth Sciences
This study presents the late Quaternary evolution of the southern Marmara region in northwestern Turkey and discusses the suitability of the area for settlements. It is based on interpretation of sediment analyses together with radiometric dates obtained from drilling cores. As three-fourths of the southern Marmara region (ca. 30,000 km2) is covered by the Susurluk Drainage Basin (SDB), the study focuses on this basin. The SDB has a concave surface morphology dipping northward, with highlands in the south (ca. 1300-1700 m a.s.l.) and lowlands in the north (ca. 0-250 a.s.l.). Lake Manyas, Lake Ulubat, and south-north flowing rivers, together with …
Sensorless Second-Order Switching Surface For A Three-Level Boost Converter, Tarek Messikh, Nasrudin Abd Rahim, Saad Mekhilef
Sensorless Second-Order Switching Surface For A Three-Level Boost Converter, Tarek Messikh, Nasrudin Abd Rahim, Saad Mekhilef
Turkish Journal of Electrical Engineering and Computer Sciences
This paper proposes a sensorless second-order switching surface to control a three-level boost converter (TLBC). A predictive current method is proposed to reduce the number of sensors in the normal second-order switching surface method. Based on a developed model of the TLBC, the current is estimated and a switching surface is formulated in the state-energy plane. Simulation and hardware tests are carried out to verify the viability and the effectiveness of the proposed control technique. Results obtained show a good performance of the converter in term of DC-bus balancing and fast dynamic response under sudden load change.
Three-Channel Control Architecture For Multilateral Teleoperation Under Time Delay, Uğur Tümerdem
Three-Channel Control Architecture For Multilateral Teleoperation Under Time Delay, Uğur Tümerdem
Turkish Journal of Electrical Engineering and Computer Sciences
Multilateral teleoperation is an extension of bilateral/haptic teleoperation framework to multiple operators/robots and finds applications in haptic training. As in bilateral teleoperation, time delay is an important problem, and stability and transparency, which quantifies the performance of the teleoperation system, are critical in the design of multilateral control systems. This paper proposes a novel three-channel-based multilateral control architecture with damping injection to guarantee delay-independent L2 stability and high transparency in multilateral teleoperation systems. The theoretical and computational analyses are verified with experiment results.
Contribution Of Artificial Proprioception On A Dynamic Finger Flexion Task, Mehdi Hojatmadani, Evren Samur
Contribution Of Artificial Proprioception On A Dynamic Finger Flexion Task, Mehdi Hojatmadani, Evren Samur
Turkish Journal of Electrical Engineering and Computer Sciences
There has been a considerable effort to provide sensory feedback for myoelectric prostheses. Among the solutions provided in the literature, sensory substitution is an easy and cost-effective way to provide feedback through different sensory modalities at different locations on the body. In this study, we evaluate the effect of sensory substitution of force and position feedback on a two-degree-of-freedom dynamic finger flexion task. For this purpose, a new methodology and an experimental setup are developed. The experimental methodology is based on the "strength-dexterity test", working on the principle of buckling of compression springs. The experimental setup comprises a haptic interface, …
Optimized Modeling Of Ni-Mh Batteries Primarily Based On Taguchi Approach And Evaluation Of Used Ni-Mh Batteries, Hani Muhsen, Ahmad Al-Muhtady
Optimized Modeling Of Ni-Mh Batteries Primarily Based On Taguchi Approach And Evaluation Of Used Ni-Mh Batteries, Hani Muhsen, Ahmad Al-Muhtady
Turkish Journal of Electrical Engineering and Computer Sciences
This paper aims to generate an optimized model of the Ni-MH battery based on the Taguchi method and it further aims to evaluate used Ni-MH batteries that served in hybrid electric vehicles and electric vehicles. The status of twelve used Ni-MH batteries is studied to determine their usefulness after their life cycle in automotive applications. The status of used batteries is evaluated by investigating their state of charge, remaining useful life, and degradation in performance. Accordingly, the tested batteries are classified into four categories and they are proposed to serve in different applications. The novelty of the work lies in …
Evaluation Of Power System Robustness In Order To Prevent Cascading Outages, Farnaaz Hajbani, Heresh Seyedi, Kazem Zare
Evaluation Of Power System Robustness In Order To Prevent Cascading Outages, Farnaaz Hajbani, Heresh Seyedi, Kazem Zare
Turkish Journal of Electrical Engineering and Computer Sciences
Power system robustness against overload condition is a challenging issue in the fields of power system planning and operation. In this paper, two indices are proposed to evaluate power system robustness. The proposed indices are used to identify critical lines whose failure is due to overload, leading the power system to cascading outages and blackout. The first proposed index is a linear index. The second index is based on graph theory metrics. To prevent cascading outages, system robustness is calculated for all N-1 and N-2 contingencies. The lines whose outages lead to the smallest robustness values are considered as critical …
Improved Vsm Control Of Pmsg-Based Wind Farms For Transient Stability Enhancement, Mohamed Abbes, Ines Mehouachi, Souad Chebbi
Improved Vsm Control Of Pmsg-Based Wind Farms For Transient Stability Enhancement, Mohamed Abbes, Ines Mehouachi, Souad Chebbi
Turkish Journal of Electrical Engineering and Computer Sciences
This paper analyzes the optimal control strategy of PMSG-based wind farms during faults in order to improve the transient stability of a power system with a high penetration rate of wind power. The investigated control strategies are the unity power factor (UPF), reactive power control (RPC), and particularly the concept of virtual synchronous machine (VSM). The transient stability level is assessed using the critical clearing time index, which was calculated based on trajectory sensitivity analysis. In light of the obtained results, it was found that RPC gives the best transient stability level, followed by the classical VSM control. Hence, an …
Determination Of Distance Between Dc Traction Power Centers In A 1500-V Dc Subway Line With Artificial Intelligence Methods, Mehmet Taci̇ddi̇n Akçay, İlhan Kocaarslan
Determination Of Distance Between Dc Traction Power Centers In A 1500-V Dc Subway Line With Artificial Intelligence Methods, Mehmet Taci̇ddi̇n Akçay, İlhan Kocaarslan
Turkish Journal of Electrical Engineering and Computer Sciences
The electrification system in rail systems is designed with regard to the operating data and design parameters. While the electrification system is formed, the minimum voltage rating that the traction force requires during the operation needs to be provided. The highest value of the voltage drop occurring on the line is determined by the distance between power centers. This value needs to be kept within certain limits for the continuity of operation. In this study, the determination of the distance between DC traction power centers for a 1500-V DC-fed rail system is done by means of the adaptive neuro-fuzzy inference …
A Fuzzy Model Of Directional Relationships From The Phi-Descriptor, Mohammad Naeem, Nasir Ahmad, Sahib Khan, Asma Gul
A Fuzzy Model Of Directional Relationships From The Phi-Descriptor, Mohammad Naeem, Nasir Ahmad, Sahib Khan, Asma Gul
Turkish Journal of Electrical Engineering and Computer Sciences
Directional spatial relationships are a category of spatial relationships and have applications in the fields of image processing, geographic information systems, natural language processing, and robot navigation. They can be directly extracted from images or can be interpreted from a type of image descriptors called the relative position descriptors. Examples of relative position descriptors are the angle histogram, the force histogram, and the recently proposed phi-descriptor. So far, fuzzy models of directional spatial relationships from the angle histogram and force histograms have been proposed in the literature. These include the compatibility method, the aggregation method, and the method of effective …