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

Physical Sciences and Mathematics Commons

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

Articles 1 - 30 of 626

Full-Text Articles in Physical Sciences and Mathematics

Uplift Of Anatolia, Aral I. Okay, Massimiliano Zattin, Ercan Özcan, Gürsel Sunal Jan 2020

Uplift Of Anatolia, Aral I. Okay, Massimiliano Zattin, Ercan Özcan, Gürsel Sunal

Turkish Journal of Earth Sciences

The Cenozoic history of the Anatolian Plateau is investigated using the distribution of the last Cenozoic marine strata, the ages of Neogene continental sediments and magmatic rocks, and thermochronology. In central and northern Anatolia, the youngest marine sediments are of Middle Eocene age and show that the region has been above the sea level since ca. 41 Ma. The preservation of marine Eocene sequences over large regions and widespread distribution of Neogene continental sediments point to minor erosion or subsidence, except in the Miocene core complexes, and indicate average surface uplift or subsidence rates of less than 0.05 km/Myr since …


Eocene-Oligocene Succession At Kıyıköy (Midye) On The Black Sea Coast In Thrace, Aral I. Okay, Michael D. Simmons, Ercan Özcan, Stephen Starkie, Michael D. Bidgood, Andrew R.C. Kylander-Clark Jan 2020

Eocene-Oligocene Succession At Kıyıköy (Midye) On The Black Sea Coast In Thrace, Aral I. Okay, Michael D. Simmons, Ercan Özcan, Stephen Starkie, Michael D. Bidgood, Andrew R.C. Kylander-Clark

Turkish Journal of Earth Sciences

A belt of Upper Eocene-Lower Oligocene marine sedimentary rocks extends from Kıyıköy on the Black Sea coast to Pınarhisar in the Thrace Basin, suggesting a marine connection between the Black Sea and the Thrace Basin during this period. The Cenozoic succession of this marine corridor was studied in the vicinity of Kıyıköy along two measured stratigraphic sections. The sequence lies unconformably over metamorphic basement rocks and consists of ~75 m of bioclastic limestone and sandstone of the Soğucak Formation, overlain by ~40 m of limestone, marl, mudstone, sandstone, and acidic tuff, which are assigned to the newly defined Servez Formation. …


Determining The Lake Protected Zones Using Gis-Based Drastic Model To Groundwatervulnerability In Salda Lake Basin (Burdur/Turkey), Si̇mge Varol, Ayşen Davraz, Erhan Şener, Şehnaz Şener, Fatma Aksever, Bülent Kirkan, Ahmet Tokgözlü Jan 2020

Determining The Lake Protected Zones Using Gis-Based Drastic Model To Groundwatervulnerability In Salda Lake Basin (Burdur/Turkey), Si̇mge Varol, Ayşen Davraz, Erhan Şener, Şehnaz Şener, Fatma Aksever, Bülent Kirkan, Ahmet Tokgözlü

Turkish Journal of Earth Sciences

Groundwater quality is a crucial parameter for sustainable wetland management. The evaluation of the aquifer vulnerability is important for the protection of groundwater resources. The DRASTIC model is the most significant technique for the assessment of aquifer vulnerability. This study aimed to build a vulnerability map for groundwater of the Salda Lake wetland basin by DRASTIC method in a GIS environment. Seven environmental parameters (depth to water table, net recharge, aquifer media, soil media, topography, impact of the vadose zone media, and hydraulic conductivity of the aquifer) were used in the DRASTIC method and GIS was used to constitute a …


Evolution Of Two Overlapping Sand-Rich Clastic Submarine Fans In The Lower Mioceneadana Basin, Southern Turkey: Contribution From A New Palaeocurrent Analysis, Daniel Bayer Da Silva, Bryan Cronin, Hasan Çeli̇k, Karin Goldberg, Benjamin Christopher Kneller, Kemal Gürbüz Jan 2020

Evolution Of Two Overlapping Sand-Rich Clastic Submarine Fans In The Lower Mioceneadana Basin, Southern Turkey: Contribution From A New Palaeocurrent Analysis, Daniel Bayer Da Silva, Bryan Cronin, Hasan Çeli̇k, Karin Goldberg, Benjamin Christopher Kneller, Kemal Gürbüz

Turkish Journal of Earth Sciences

A complete longitudinal profile from the continental shelf break to the basin floor includes a significant and well-exposed turbidite system at the northern edge of the Adana Basin, one of a series of foreland basins in southern Turkey. This study focused on the evolutionary interpretation of 2 coeval submarine fans, the Western Fan and the Eastern Fan, in the Upper Burdigalian-Lower Serravallian Cingöz Formation. The Western Fan was fed by a single major canyonised feeder from the west, and the Eastern Fan was fed by multiple feeder channels to the north. The Western Fan originated as a confined system with …


On Basicity Of The System Of Eigenfunctions Of One Discontinuous Spectral Problem For Second Order Differential Equation For Grand-Lebesgue Space, Yusuf Zeren, Miqdad Ismailov, Fati̇h Şi̇ri̇n Jan 2020

On Basicity Of The System Of Eigenfunctions Of One Discontinuous Spectral Problem For Second Order Differential Equation For Grand-Lebesgue Space, Yusuf Zeren, Miqdad Ismailov, Fati̇h Şi̇ri̇n

Turkish Journal of Mathematics

Basicity of the system of eigenfunctions of some\textbf{ }discontinuous spectral problem for a second order differential equation with spectral parameter in boundary condition for grand-Lebesgue space $L_{p)} (-1;1)$ is studied in this work. Since the space is nonseparable, a subspace suitable for the spectral problem is defined. The subspace $G_{p)} (-1;1)$ of $L_{p)} (-1;1)$ generated by shift operator is considered. Basicity of the system of eigenfunctions for the space $G_{p)} (-1;1)\oplus C$, $1


Geochemistry And Mineralogy Of The Shallow Subsurface Red Sea Coastal Sediments, Rabigh, Saudi Arabia: Provenance And Paleoenvironmental Implications, Rabea Haredy, Ibrahim Mohamed Ghandour Jan 2020

Geochemistry And Mineralogy Of The Shallow Subsurface Red Sea Coastal Sediments, Rabigh, Saudi Arabia: Provenance And Paleoenvironmental Implications, Rabea Haredy, Ibrahim Mohamed Ghandour

Turkish Journal of Earth Sciences

Mineralogical and geochemical characteristics of the shallow subsurface sediments retrieved from a short sediment core (2.05 m long) collected from the tidal flat south of Al-Kharrar Lagoon, Rabigh area, Saudi Arabia, are presented to determine the impact of temporal change of depositional environment and distinguish the principal control(s) on their chemical composition. The sediments are dominantly siliciclastic, consisting of two vertically stacked sedimentary facies: lagoonal (LG) gray silt-rich mud to argillaceous very fine sand at the base and intertidal flat (TF) brown mud and argillaceous very fine-grained sands at the top. The sediments of the two facies are similar in …


Petrology Of The Late Triassic Mafic Volcanic Rocks From The Antalya Complex, Southernturkey: Evidence For Mantle Source Characteristics During The Neotethyan Rifting, Utku Bağci, Tamer Rizaoğlu, Güzi̇de Önal, Osman Parlak Jan 2020

Petrology Of The Late Triassic Mafic Volcanic Rocks From The Antalya Complex, Southernturkey: Evidence For Mantle Source Characteristics During The Neotethyan Rifting, Utku Bağci, Tamer Rizaoğlu, Güzi̇de Önal, Osman Parlak

Turkish Journal of Earth Sciences

The Antalya Complex in southern Turkey comprises a number of autochthonous and allochthonous units that originated from the Southern Neotethys. Late Triassic volcanic rocks are widespread in the Antalya Complex and are important for the onset of the rifting stage of the southern Neotethys. The studied Late Triassic volcanic rocks within the Antalya Complex are exposed in the southern part of Saklıkent (Antalya) region. They are represented by pillow, massive, and columnar-jointed lava flows with volcaniclastic breccias and pelagic limestone intercalations. Spilitic basalts exhibit intersertal, microlithic porphyritic, and ophitic textures and are represented by plagioclase, pyroxene, and olivine. Secondary phases …


Middle Eocene High-K Acidic Volcanism In The Princes' Islands (İstanbul) And Itsgeodynamic Implications, Fati̇h Şen Jan 2020

Middle Eocene High-K Acidic Volcanism In The Princes' Islands (İstanbul) And Itsgeodynamic Implications, Fati̇h Şen

Turkish Journal of Earth Sciences

The rock assemblages of the Princes? Islands, which are located to the south of mainland İstanbul, are regarded as parts of the Lower Paleozoic quartz sandstones, although they were initially considered as volcanic rocks by Swan in 1868. They differ from quartz sandstones by their vesicular texture and are devoid of any stratigraphic layering. Their mineral constituents are plagioclase (30%-35%), feldspar (35%-40%), and quartz (20%-25%), corresponding to rhyolite. The crystallization age of the rhyolites is 45.66 ± 0.84 Ma on the basis of the U-Pb zircon data. They show high-K calc-alkaline affinity. On primitive-normalized spider diagrams, negative anomalies of Ba, …


Epidote - Lawsonite Coexistence In Blueschist-Facies Blockfrom The Tavşanlı Zone - Turkey: Petrological Implications, Mete Çeti̇nkaplan Jan 2020

Epidote - Lawsonite Coexistence In Blueschist-Facies Blockfrom The Tavşanlı Zone - Turkey: Petrological Implications, Mete Çeti̇nkaplan

Turkish Journal of Earth Sciences

Metamorphic evolution of an epidote-lawsonite blueschist sample characterized by the coexistence of lawsonite and epidote from Sivrihisar area (Tavşanlı Zone) was studied herein in terms of petrology and mineral equilibria. Based on the textural evidence and phase composition, 2 prograde stages, defined by assemblage-I and -II, and 1 retrograde stage were recognized. Assemblage-I indicates epidote-blueschist facies conditions (12 ± 1 kbar / 485 ± 10 °C). Assemblage-II is characterized by the coexistence of epidote and lawsonite (17 ± 1 kbar / 515 ± 10 °C) corresponding to the interface of lawsonite blueschist and epidote blueschist facies. Phase diagram calculations and …


Review Of Late Cretaceous Volcanogenic Massive Sulfide Mineralization In The Easternpontides, Ne Turkey, Mustafa Kemal Revan Jan 2020

Review Of Late Cretaceous Volcanogenic Massive Sulfide Mineralization In The Easternpontides, Ne Turkey, Mustafa Kemal Revan

Turkish Journal of Earth Sciences

The production of Cu-Zn from volcanogenic massive sulfide (VMS) deposits in the eastern Pontides began in the early 1900s, with the exploitation of high-grade ores scattered across the district. The district still possesses economically important blind VMS and associated sulfide deposits. Careful descriptive documentation of the typical features of these VMS ores illustrated the geological characteristics that are important in identifying ore localities and can be used to define exploration targets. The eastern Pontide VMS deposits are examples of volcanic-hosted massive sulfide deposits that exhibit many of the characteristics typical of bimodal-felsic-type VMS mineralization. Nearly all known VMS deposits in …


Assessment Of Element Concentrations In Surface Sediment Samples Fromsığacık Bay (Eastern Aegean), Özde Bakak, Fi̇li̇z Küçüksezgi̇n, Fai̇k Erdeni̇z Özel Jan 2020

Assessment Of Element Concentrations In Surface Sediment Samples Fromsığacık Bay (Eastern Aegean), Özde Bakak, Fi̇li̇z Küçüksezgi̇n, Fai̇k Erdeni̇z Özel

Turkish Journal of Earth Sciences

Concentrations of Al, Fe, As, Co, Cr, Cu, Mn, Ni, Pb, Zn, Hg, and organic carbon, and grain size distribution were investigated in the surface sediments of 7 sampling stations in the Sığacık Bay (western Anatolia) in December 2016. At all of the sampling stations, the concentrations of Pb, Ni, Cr, and As were higher than the average shale values. The highest concentrations of Pb, Cu, Zn, As, and Hg were found at stations near Doğanbey Cape. The possible sources of pollution were evaluated using several parameters: the enrichment factor (Ef), contamination factor (Cf), and contamination degree (Cd). The Ef …


Geochemistry, Risk Assessment, And Pb Isotopic Evidence For Sources Of Heavy Metals Instream Sediments Around The Ulukışla Basin, Niğde, Southern Turkey, Abdurrahman Lermi̇, Emmanuel Daanoba Sunkari Jan 2020

Geochemistry, Risk Assessment, And Pb Isotopic Evidence For Sources Of Heavy Metals Instream Sediments Around The Ulukışla Basin, Niğde, Southern Turkey, Abdurrahman Lermi̇, Emmanuel Daanoba Sunkari

Turkish Journal of Earth Sciences

Concentrations of selected elements (Al, Fe, Mn, Mo, As, Cd, Cu, Cr, Ni, Co, Pb, Sb, and Zn) and Pb isotope ratios were determined in 53 sediments from Alihoca, Gümüş, Horoz, and Çakıt streams around the south-central Taurides (Ulukışla Basin), Niğde, which is a known mining province in Turkey. Several pollution and risk assessment indices were used to assess possible heavy metal pollution in the stream sediments and the associated potential ecological risks. Concentrations of As, Cd, Cu, Cr, Ni, Co, Pb, Sb, and Zn were elevated in the streams located near ancient mines, active mines, and slag piles in …


Assessment Of Acid Mine Drainage Formation Using Geochemical And Static Tests In Mutki(Bitlis, Se Turkey) Mineralization Area, Mehmet Ali̇ Gücer, Selçuk Alemdağ, Enver Akaryali Jan 2020

Assessment Of Acid Mine Drainage Formation Using Geochemical And Static Tests In Mutki(Bitlis, Se Turkey) Mineralization Area, Mehmet Ali̇ Gücer, Selçuk Alemdağ, Enver Akaryali

Turkish Journal of Earth Sciences

In this study, geochemical analyses, as well as short-term contact leaching and acid-base accounting tests, were carried out to determine the occurrence of acid mine drainage (AMD) by static tests in the ore stockpile areas at the Mutki Cu-Fe-Cr deposit (Bitlis, SE Turkey). According to the short-term contact leaching tests, the high enrichment in trace element concentrations in ore-bearing samples, especially in potentially toxic metals such as Cr, Cu, Mn, and Zn, were directly related to sulphide and oxide mineralizations. The pH (3.27-4.05) values of water samples, together with the classification of the intracontinental water resources, indicated that the water …


Geochemical, Stable (O, C, And B) And Radiogenic (Sr, Nd, Pb) Isotopic Data From Theeskişehir-Kızılcaören (Nw-Anatolia) And The Malatya-Kuluncak (E-Central Anatolia)F-Ree-Th Deposits, Turkey: Implications For Nature Of Carbonate-Hosted Mineralization, Okay Çi̇men, Loretta Corcoran, Corinne Kuebler, Stefanie Simonetti, Antonio Simonetti Jan 2020

Geochemical, Stable (O, C, And B) And Radiogenic (Sr, Nd, Pb) Isotopic Data From Theeskişehir-Kızılcaören (Nw-Anatolia) And The Malatya-Kuluncak (E-Central Anatolia)F-Ree-Th Deposits, Turkey: Implications For Nature Of Carbonate-Hosted Mineralization, Okay Çi̇men, Loretta Corcoran, Corinne Kuebler, Stefanie Simonetti, Antonio Simonetti

Turkish Journal of Earth Sciences

In Turkey, the largest fluorine (F)-rare earth element (REE)-thorium (Th) deposits are located within the Eskişehir-Kızılcaören (north-western Anatolia) and the Malatya-Kuluncak (east-central Anatolia) regions, and these are associated with Oligocene extensional alkaline volcanic and Late Cretecaous-Early Paleocene postcollisional intrusive rocks, respectively. In the Kızılcaören region, the basement units include the Triassic Karakaya Complex and the Late Cretaceous oceanic units (Neotethyan suture) that are cut and overlain by phonolite and carbonatite intrusions and lava flows. In the Kuluncak region, the plutonic rocks are mainly composed of syenite, quartz syenite, and rare monzonite, and these cut the late-Cretaceous Karapınar limestone, which hosts …


Last Glacial Climate Oscillations And Sudden Environmental Changes Investigated In Stalagmites From Southwest Sulawesi, Western Pacific, Ezgi̇ Ünal İmer, İbrahi̇m Tonguç Uysal, Emma St Pierre, Jian Xin Zhao, James Shulmeister Jan 2020

Last Glacial Climate Oscillations And Sudden Environmental Changes Investigated In Stalagmites From Southwest Sulawesi, Western Pacific, Ezgi̇ Ünal İmer, İbrahi̇m Tonguç Uysal, Emma St Pierre, Jian Xin Zhao, James Shulmeister

Turkish Journal of Earth Sciences

We investigated two stalagmites from the Saripa Cave and Bumi Cave in southern Sulawesi, Indonesia, using high-precision U-series dating and high-resolution trace element and C-O-Sr isotope analysis. The growth record (from 10.4 ± 0.1 ka to 77.4 ± 0.9 ka) of the Saripa Cave stalagmite (SR04-ST3) is fragmented with two major (at the top: 10.4-11.6 ka and middle: 43.8-44.7 ka sections of the stalagmite) and some short (middle and bottom sections) growth phases, interrupted by long-lasting growth hiatuses. Both the timing of the growth phases and the δ18O values for different growth phases are correlated with those of cold/dry (~22 …


Upper Paleocene-Lower Eocene Calcareous Nannofossil Stratigraphy At The Misheiti Section, Central Sinai, Egypt, Atef M. Kasem, Sherwood Wise, Mahmoud Faris, Sherif Farouk, Esam Zahran Jan 2020

Upper Paleocene-Lower Eocene Calcareous Nannofossil Stratigraphy At The Misheiti Section, Central Sinai, Egypt, Atef M. Kasem, Sherwood Wise, Mahmoud Faris, Sherif Farouk, Esam Zahran

Turkish Journal of Earth Sciences

Calcareous nannofossil, δ13C, δ18O, and carbonate content data were used to define and reveal the variations across the latest Paleocene-earliest Eocene interval at the Misheiti Section, Central Sinai, Egypt. The upper part of Tarawan Formation, the Esna Formation, and the lowermost Thebes Formation were included in this study. In this study, the Esna Formation is informally divided into Hanadi/Mahmiya and Abu Had members. Four calcareous nannofossil zones (NP9, NP10, NP11, and NP12) and four subzones (NP9a, NP9b, NP10a, and NP10b) were recognized. The biostratigraphic importance of significant calcareous nannofossil bioevents associated with the P/E boundary was discussed. The LOs of …


Alluvial-Lacustrine Sedimentation And Volcaniclastic Deposition In An Intracontinental Tectonic Graben: Paleoenvironmental Evolution Of The Neogene Sinanpaşa Basin, West-Central Turkey, Eli̇f Akiska, Baki̇ Erdoğan Varol Jan 2020

Alluvial-Lacustrine Sedimentation And Volcaniclastic Deposition In An Intracontinental Tectonic Graben: Paleoenvironmental Evolution Of The Neogene Sinanpaşa Basin, West-Central Turkey, Eli̇f Akiska, Baki̇ Erdoğan Varol

Turkish Journal of Earth Sciences

This study reports on the Sinanpaşa Basin, a typical example of the Miocene tectonic intracontinental grabens formed in West Anatolia, Turkey. The study reconstructs the paleoenvironmental and paleogeographic history of the graben based on a detailed sedimentological analysis of basin-fill deposits exposed mainly near the graben's northern and southern margins. The sedimentary paleoenvironments in the graben range from basin-margin alluvial fan systems and basin-axis fluvial distributary system to an intrabasinal shallow lake environment surrounded by peat-forming mires, changing from carbonate to more clayey, episodically evaporitic, and shifting its shorelines considerably. The spatial distribution and stratigraphic stacking of these paleoenvironments indicate …


Traces Of Mediterranean Origin Holocene Transgression In The Drainage Basin Of Riva-Çayağzı Creek Of The Black Sea (Northeastern İstanbul-Turkey), Bülent Doğan, Ahmet Karakaş, Ati̇ke Nazi̇k, İbrahi̇m Engi̇n Meri̇ç Jan 2020

Traces Of Mediterranean Origin Holocene Transgression In The Drainage Basin Of Riva-Çayağzı Creek Of The Black Sea (Northeastern İstanbul-Turkey), Bülent Doğan, Ahmet Karakaş, Ati̇ke Nazi̇k, İbrahi̇m Engi̇n Meri̇ç

Turkish Journal of Earth Sciences

The Riva-Çayağzı Creek (İstanbul, Black Sea) pours into the Black Sea from the coasts of Turkey. In the drainage basin of this creek, both deep and shallow drillings were undertaken, and the minimum thickness of Holocene stratigraphy was determined as 30 m. The Holocene young deposits are mainly composed of fine-grained sediments and clay, which has the most prominent thickness. The energy of water during the sedimentation process was low and stagnant in the Riva-Çayağzı Creek basin. When the marine mollusc fossils obtained from the shallow boring cores are evaluated, it can be deduced that the sea level in the …


Geochemical And Industrial Properties Of The Kejal Kaolin Deposit, Nw Iran, Tohid Nouri, Rahim Masoumi Jan 2020

Geochemical And Industrial Properties Of The Kejal Kaolin Deposit, Nw Iran, Tohid Nouri, Rahim Masoumi

Turkish Journal of Earth Sciences

The Kejal kaolin deposit, situated in the northwest of Iran, is considered a small part of the Hashtjin hydrothermal zone. The kaolinization process in this deposit has occurred in ignimbritic and volcanic tuff parent rocks in different grades such that severely kaolinized samples can be found in the middle section of the kaolinization profile. Kaolinite is the most abundant clay mineral in the studied samples. Quartz and cristobalite are the main minerals while anatase is the minor mineral of the kaolin samples. Among the major oxides, SiO2, Al2O3, and TiO2 show the highest concentrations in kaolin samples. The mass change …


Geochemistry And Petrography Of Beach Sands Along The Western Coast Of Ghana:Implications For Provenance And Tectonic Settings, Mahamuda Abu, Emmanuel Daanoba Sunkari Jan 2020

Geochemistry And Petrography Of Beach Sands Along The Western Coast Of Ghana:Implications For Provenance And Tectonic Settings, Mahamuda Abu, Emmanuel Daanoba Sunkari

Turkish Journal of Earth Sciences

The paleoweathering, provenance, and tectonic setting of sediments of the western coast of Ghana were unraveled using the geochemistry of 29 beach sands, which are characterized by coarse-, medium-, and fine-grained sizes. The coarse-grained beach sands contain higher SiO2 content (2.9-96 wt.%) than the medium-grained (4.9-94 wt.%) and fine-grained (16.1-90.7 wt.%) sands, implying that the increase in grain size is related to the increase in SiO2 content. Al2O3 and CaO concentrations are higher in the fine- and medium-grained sands than the coarse-grained sands. The beach sands are compositionally immature based on the index of compositional variable values (1.17-141) and Th/Sc …


Excess Lifetime Cancer Risk Due To Natural Radioactivity In Gümüşhane Province, Ne Turkey, Nafiz Maden, Enver Akaryali, Mehmet Ali̇ Gücer Jan 2020

Excess Lifetime Cancer Risk Due To Natural Radioactivity In Gümüşhane Province, Ne Turkey, Nafiz Maden, Enver Akaryali, Mehmet Ali̇ Gücer

Turkish Journal of Earth Sciences

In this study, 162 in situ measurements of 238U, 232Th, and 40K radionuclide concentrations dataset taken by the gamma-ray spectrometer in Gümüşhane, Turkey are presented. The gamma ray measurements were performed by a 512-channel, three-window gamma-ray spectrometry equipment made by GF Instruments. We first observed the radionuclides of the 238U, 232Th, and 40K values in Gümüşhane. We then calculated the hazard indices of gamma radiation such as annual effective dose equivalent (AEDE), internal and external hazard index (Hin, Hex), and excess lifetime cancer risk (ELCR) based on the radionuclide abundances of 238U, 232Th, and 40K for the first time. In …


Latest Priabonian Larger Benthic Foraminiferal Assemblages At The Demise Of Thesoğucak Carbonate Platform (Thrace Basin And Black Sea Shelf, Nw Turkey):Implications For The Shallow Marine Biostratigraphy, Ali̇ Osman Yücel, Ercan Özcan, Ümi̇tcan Erbi̇l Jan 2020

Latest Priabonian Larger Benthic Foraminiferal Assemblages At The Demise Of Thesoğucak Carbonate Platform (Thrace Basin And Black Sea Shelf, Nw Turkey):Implications For The Shallow Marine Biostratigraphy, Ali̇ Osman Yücel, Ercan Özcan, Ümi̇tcan Erbi̇l

Turkish Journal of Earth Sciences

The Eocene-Oligocene transition corresponds to a significant biotic turnover globally. In shallow marine realms, the larger benthic foraminifera (LBF) belonging to most nummulitids and all orthophragminids became extinct at or near the Eocene/Oligocene boundary, reflecting the environmental deterioration. We here record the advanced developmental stages of midlatitude LBF from the Soğucak Carbonate Platform in NW Turkey on the brink of their extinction in the Tethys. The LBF assemblages in the uppermost part of the platform, exposed in Gökçetepe and Karaburun in the Thrace Basin and Black Sea shelf, are represented by the dominant occurrence of Heterostegina d'Orbigny, 1826, Spiroclypeus Douville, …


Late Eocene To Early Oligocene Palynostratigraphy Of The Western Black Sea, Easternparatethys, Recep Hayretti̇n Sancay, Zühtü Bati Jan 2020

Late Eocene To Early Oligocene Palynostratigraphy Of The Western Black Sea, Easternparatethys, Recep Hayretti̇n Sancay, Zühtü Bati

Turkish Journal of Earth Sciences

The Eastern Thrace and Western Black Sea basins provide unique perspectives on the palaeogeographic reconstructions of the Paratethys. Although very thick and extensive Oligocene outcrops and well sections exist in the Thrace Basin, only a few comparable sections are available in the Black Sea onshore areas. In this study, five measured stratigraphic sections of Eocene to Oligocene age from the margins of the Western Black Sea were studied and palynomorph assemblages were identified quantitatively. Index dinoflagellate cyst events and a palynological biozonation as established in the Mediterranean were applied successfully. Priabonian units contain the Aal biozone, whereas Rupelian successions were …


The Igneous Rock Intrusion Beneath Ambon And Seram Islands, Eastern Indonesia, Basedon The Integration Of Gravity And Magnetic Inversion: Its Implications For Geothermalenergy Resources, Richard Lewerissa, Sismanto Sismanto, Ari Setiawan, Subagyo Pramumijoyo Jan 2020

The Igneous Rock Intrusion Beneath Ambon And Seram Islands, Eastern Indonesia, Basedon The Integration Of Gravity And Magnetic Inversion: Its Implications For Geothermalenergy Resources, Richard Lewerissa, Sismanto Sismanto, Ari Setiawan, Subagyo Pramumijoyo

Turkish Journal of Earth Sciences

Ambon and Seram islands in eastern Indonesia are located in the convergence zone of three major plates, causing this area to have many geothermal manifestations on the surface. A subsurface geological study on Ambon and Seram has been conducted based on the integration of gravity and magnetic inversion modeling to determine the intrusion of igneous rock as a potential source of geothermal energy. The gravity and magnetic inversion utilized gravity and magnetic anomaly data from the World Gravity Map (WGM) and the Earth Magnetic Anomaly Grid (EMAG), as well as the CRUST 1.0 global earth crust model, as the constraints. …


A Review On Embedded Field Programmable Gate Array Architectures And Configuration Tools, Khouloud Bouaziz, Abdulfattah M. Obeid, Sonda Chtourou, Mohamed Abid Jan 2020

A Review On Embedded Field Programmable Gate Array Architectures And Configuration Tools, Khouloud Bouaziz, Abdulfattah M. Obeid, Sonda Chtourou, Mohamed Abid

Turkish Journal of Electrical Engineering and Computer Sciences

Nowadays, systems-on-chip have reached a level where nonrecurring engineering costs have become a great challenge due to the increase of design complexity and postfabrication errors. Embedded field programmable gate arrays (eFPGAs) represent a viable alternative to overcome these issues since they provide postmanufacturing flexibility that can reduce the number of chip redesigns and amortize chip fabrication cost. In this paper, we present an overview on eFPGAs and their architectures, computer aided design (CAD) tools, and design challenges. An eFPGA must be well-designed and accompanied by an optimized CAD tool suite to respond to target application's requirements in terms of power …


Simulation And Analysis Of Wind Turbine Radar Echo Based On 3-D Scattering Point Model, Jiangong Zhang, Bin Hao, Bo Tang, Li Huang, Jiawei Yang Jan 2020

Simulation And Analysis Of Wind Turbine Radar Echo Based On 3-D Scattering Point Model, Jiangong Zhang, Bin Hao, Bo Tang, Li Huang, Jiawei Yang

Turkish Journal of Electrical Engineering and Computer Sciences

Wind turbine (WT) arrays in wind farms can cause serious interference on nearby radar stations. This interference could be filtered out if wind turbine radar echo (WTRE) can be obtained accurately. Considering the singleness of in-field experiments, numerical simulation became the majority among such works, but few of them reached necessary accuracy. Therefore, we propose a solution method of WTRE based on three-dimensional (3-D) scattering point model. Firstly, we use the nonuniform rational B-spline to build the 3-D model of WT. Secondly, based on the method of moments (MoM), the Rao-Wilton-Gisson (RWG) basis function is adopted to discretize the integral …


Design Of A High Performance Narrowband Low Noise Amplifier Using An On-Chip Orthogonal Series Stacked Differential Fractal Inductor For 5g Applications, Sunil Kumar Tumma, Bheemarao Nistala Jan 2020

Design Of A High Performance Narrowband Low Noise Amplifier Using An On-Chip Orthogonal Series Stacked Differential Fractal Inductor For 5g Applications, Sunil Kumar Tumma, Bheemarao Nistala

Turkish Journal of Electrical Engineering and Computer Sciences

Inductors play a crucial role in the design of radio frequency integrated circuits (RFICs) and they typically consume a considerably large area and have a low-quality factor at high frequencies. The employment of fractal structure in on-chip inductors helps in improving the quality factor and also reduces the overall area besides improving the inductance value. In this paper, an orthogonal series stacked differential fractal inductor is proposed and the same is used to design a low noise amplifier (LNA) for 5G band (27--30 GHz) applications. The proposed inductor is fabricated on a multilayer printed circuit board and the measurement results …


Integrated Topic Modeling And Sentiment Analysis: A Review Rating Prediction Approach For Recommender Systems, Anbazhagan Mahadevan, Michael Arock Jan 2020

Integrated Topic Modeling And Sentiment Analysis: A Review Rating Prediction Approach For Recommender Systems, Anbazhagan Mahadevan, Michael Arock

Turkish Journal of Electrical Engineering and Computer Sciences

Recommender systems (RSs) are running behind E-commerce websites to recommend items that are likely to be bought by users. Most of the existing RSs are relying on mere star ratings while making recommendations. However, ratings alone cannot help RSs make accurate recommendations, as they cannot properly capture sentiments expressed towards various aspects of the items. The other rich and expressive source of information available that can help make accurate recommendations is user reviews. Because of their voluminous nature, reviews lead to the information overloading problem. Hence, drawing out the user opinion from reviews is a decisive job. Therefore, this paper …


Retinal Vessel Segmentation Using Modified Symmetrical Local Threshold, Umar Özgünalp Jan 2020

Retinal Vessel Segmentation Using Modified Symmetrical Local Threshold, Umar Özgünalp

Turkish Journal of Electrical Engineering and Computer Sciences

Retinal vessel segmentation is important for the identification of many diseases including glaucoma, hypertensive retinopathy, diabetes, and hypertension. Moreover, retinal vessel diameter is associated with cardiovascular mortality. Accurate detection of blood vessels improves the detection of exudates in color fundus images, as well as detection of the retinal nerve, optic disc, or fovea. A retinal vessel is a darker stripe on a lighter background. Thus, the objective is very similar to the lane detection task for intelligent vehicles. A lane on a road is a light stripe on a darker background (i.e. asphalt). For lane detection, the symmetrical local threshold …


Fuzzy C-Means Directional Clustering (Fcmdc) Algorithm Using Trigonometric Approximation, Orhan Kesemen, Özge Tezel, Eda Özkul, Buğra Kaan Ti̇ryaki̇ Jan 2020

Fuzzy C-Means Directional Clustering (Fcmdc) Algorithm Using Trigonometric Approximation, Orhan Kesemen, Özge Tezel, Eda Özkul, Buğra Kaan Ti̇ryaki̇

Turkish Journal of Electrical Engineering and Computer Sciences

Cluster analysis is widely used in data analysis. Statistical data analysis is generally performed on the linear data. If the data has directional structure, classical statistical methods cannot be applied directly to it. This study aims to improve a new directional clustering algorithm which is based on trigonometric approximation. The trigonometric approximation is used for both descriptive statistics and clustering of directional data. In this paper, the fuzzy clustering algorithms (FCD and FCM4DD) improved for directional data and the proposed method are carried out on some numerical and real data examples, and the simulation results are presented. Consequently, these results …