Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Uzun, Sevda(67)
- Merdan, Mehmet(59)
- Duran, Celal(49)
- Ozdes, Duygu(46)
- Kaygusuz, Abdullah(45)
- Demir, Selim(37)
- Turan, Ibrahim(37)
- Karsli, Orhan(36)
- Öztürk, Serkan(35)
- Dokuz, Abdurrahman(34)
- Araz, Onur(32)
- Kandemir, Raif(31)
- Kulakaç, Nurşen(29)
- Sipahi, Ferkan(29)
- Arslan, Mehmet(27)
- Baltaci, Cemalettin(27)
- Baltacı, Cemalettin(27)
- Kurt, Kemal(27)
- Topal, Fevzi(27)
- Gücer, Mehmet Ali(25)
- Peker, Iskender(25)
- Aydin, Faruk(24)
- Bayrakdaroglu, Serdar(24)
- Maden, Nafiz(24)
- Ozturk, Samet(24)
- Vural, Alaaddin(24)
- Yolcu, Halil(24)
- Yücel, Cem(24)
- Aliyazicioglu, Yuksel(23)
- Kankal, Murat(23)
- Reis, Hatice Catal(23)
- Ürkek, Bayram(23)
- Günen, Mehmet Akif(22)
- Kurnaz, Muammer(22)
- Topal, Meryem(22)
- Karimullah, Suud Sarim(21)
- Uysal, Ibrahim(21)
- Ashyralyyev, Charyyar(20)
- Aydin, Aydanur(20)
- Bayraktar, Alemdar(20)
Yayınlar
- MakaleYalnız künye2017Scopus SJRQ3Bio-oil production from fast pyrolysis of maple fruit (acer platanoides samaras): product yields
Bahadir, Ali; Kar, Turgay; Keles, Sedat; Kaygusuz, Kamil
Purpose - The purpose of this paper is to investigate fast pyrolysis of maple fruit as an energy sources. This could serve as a solution to the energy sources problem. Design/methodology/approach - Fast pyrolysis of maple fruit (samara) was achieved in a fixed bed reactor. The pyrolysis experiments have been conducted on the sample of maple seeds to particularly determine the effects of pyrolysis temperature, particle size and sweep gas flow rate on the pyrolysis product yields. Findings - The oil of maple fruit from fast pyrolysis has good properties to be a potential candidate as a biofuel or as a source of chemicals. In addition to being environmentally desirable, it can reduce the energy cost, e.g. that Turkey imports a majority of its energy. Originality/value - The use of maple fruit for fast pyrolysis and pyrolysis conditions impact on the yields of pyrolysis liquid can be considered as novel aspects of this paper.
AtıfWoS6
İncele - MakaleAçık Erişim2017Evaluation of Antioxidant and Cytotoxic Properties of Primula vulgaris Leaf Extract
Turan, Ibrahim; Demir, Selim; Aliyazicioglu, Rezzan; Aliyazicioglu, Yuksel
Primula vulgaris belongs to the genus Primula and this genus is frequently used in traditional medicine. Numerous studies reported the antioxidant and cytotoxic effects of various extracts of different Primula species but, there were limited studies of the antioxidant and cytotoxic effect of P. vulgaris. The aim of this study was to determine the antioxidant properties and cytotoxic effects of dimethyl sulfoxide extract of leaves of P. vulgaris. The total polyphenolic content (TPC), total flavonoid content (TFC) and reducing antioxidant power of extract were evaluated using spectrophotometric procedures. The cytotoxic effects of extract were revealed on human lung (A549), liver (HepG2), breast (MCF-7), prostate (PC-3), and colon (WiDr) cancer cell lines and normal fibroblast cells using thiazolyl blue tetrazolium bromide (MTT) assay. TPC and FRAP values were 1890.1 +/- 11.2 mg gallic acid equivalents and 3233.1 +/- 176.2 mg trolox equivalents per 100 g sample, respectively. The extract showed selective cytotoxic effects on all studied cancer cell lines compared to normal fibroblast cells and IC50 values ranged from 133.3-253.8 mu g/mL. This is the first study to reveal the antioxidant properties of P. vulgaris leaf extract and its cytotoxic effect on cancer cell lines. Further studies are now needed to identify the antioxidant and cytotoxic molecules in the extract and their mechanisms.
AtıfWoS15OpenAlex6İncele - MakaleYalnız künye2017The Relationship Between Price Level and Fiscal Policy in Turkey: An Econometrical Analysis of the FTPL Approach
Bölükbas, Mehmet; Peker, Osman
The aim of this study is to investigate the Fiscal Theory of Price Level (FTPL) approach for Turkey and to determine whether monetary and fiscal policy shows a dominant regime characteristic. In this context, an empirical analysis was performed by using 2006: Q1-2015: Q4 period data with the help of Johansen Cointegration Method. According to the results of empirical analysis, it has been determined that fiscal policy is an effective policy in determining the price level in Turkey in the mentioned period because a unit change in the primary budget balance led to an increase of 4,33 units in the general price level. This finding suggests that the FTPL approach is valid for Turkey in the period 2006-2015 and fiscal policy shows the dominant regime characteristic in Turkey in the mentioned period.
AtıfWoS3İncele - MakaleAçık Erişim2017Experimental investigation of the effect of ferromagnetic particles addition on mechanical properties of magneto-rheological materials
Mazlum, Ugur; Gümrük, Recep
The ferromagnetic particle, are used in many areas due to their magnetic field sensitivity. Composite MRE materials which obtained from the combination of the matrix material with these particles are classified as a kind of smart materials. In this study, it is aimed that the compressive mechanical properties of MRE materials produced by adding four different magnetic particles in RTV (room temperature vulcanizing) silicone elastomer are investigated. As a matrix material Vario 40 silicone rubber were used, which is common in engineering application. The particle rate inside MRE materials was kept at 30% by volume. In addition, to investigate the influence of orientation of particles inside MRE materials, some samples were subjected to external magnetic field during production. These samples are named as anisotropic MRE materials while the others are described as isotropic ones. The tests showed that anisotropic samples have much more strength values according to isotropic samples. Of all, the MRE samples including BASF CN particles reveal the biggest strength values. Also, the samples were evaluated in terms of MR effect and the largest MR effect with an increase value of 201% was found for anisotropic samples including SQ-I particles with regard to the corresponding isotropic one. As a result, this study determined that the mechanical and MR properties of MRE materials seriously depend on ferromagnetic particle kind and its magnetic characteristic.
- MakaleYalnız künye2017Determination of Yield, Yield Components and Some Quality Traits in Some Two-Rowed Barley (Hordeum vulgare conv. distichon) Varieties Grown in Bafra Plain
Sirat, Abdulveli; Sezer, Ismail
This research was carried out with 12 of two-rowed barley varieties (Fahrettinbey, Cumhuriyet-50, Ozdemir-05, Kalayci-97, Cildir-02, Ince-04, Efes-98, Erciyes, Cumra-2001, Sladoran, Tarm-92 and Tokak-157/35) under Bafra Plain ecological conditions in Randomized Complete Block Design with four replications during 2007-2008 and 2008-2009 growing seasons. In this research, durations of heading and maturity, plant height (cm), spike number per m(2), spike length (cm), grain number per spike, grains weight per spike (g), harvest index (%) and grain yield (kg/da), the quality characteristics such as grain largeness ratio (%), 1000-grains weight (g), test weight (kg) and crude protein ratio (%) were investigated. Significant differences were found between genotypes for all investigated agronomic characteristics. According to the results of the 2 years; the highest grain yield obtained from Fahrettinbey (623.66 kg/da), Sladoran (596.41 kg/da) and Cumra-2001 (579.32 kg/da) varieties, the lowest grain yield obtained from Cildir-02 (409.15 kg/da) and Ozdemir-05 (425.44 kg/da) varieties. The highest 1000-grains weight, test weight and grain largeness ratio were found in Fahrettinbey, Sladoran and Cumra-2001 varieties (49.84, 47.97 and 47.32 g; 70.76, 70.61 and 69.58 kg; % 92.00, 90.25 and 90.75, respectively). Cildir-02 and Efes-98 varieties had the highest crude protein ratio (11.74 and 11.69 %), the shortest plant height was obtained from Sladoran variety (96.42 cm). The result of this study, when considered in terms of yield and quality characteristics, It has been found that Fahrettinbey, Sladoran and Cumra-2001 cultivars, appeared as promising genotypes for the conditions in Bafra Plain than other cultivars
AtıfWoS3İncele - MakaleYalnız künye2017Scopus SJRQ1Effectiveness of Black Mulberry Molasses in Prevention of Radiotherapy-Induced Oral Mucositis: A Randomized Controlled Study in Head and Neck Cancer Patients
Doǧan, Melike Demir; Can, Gulbeyaz; Meral, Rasim
Objectives: Radiation-induced oral mucositis is one of the problems experienced by 70%-80% of patients receiving radiation therapy (RT). This randomized controlled trial assessed the effectiveness of black mulberry molasses in the prevention of oral mucositis in head and neck cancer patients receiving RT. Interventions and Outcome measures: Eighty head and neck cancer patients scheduled to undergo RT to the oropharyngeal mucosa were randomly assigned to receive RT (42) or RT plus mulberry molasses (38). The research data were collected with a Patient Description Form, Common Terminology Criteria for Adverse Events, version 4.0, an Oral Assessment Guide, and the University of Washington Quality of Life Assessment Questionnaire. Results: The incidence and severity of oral mucositis were lower in the black mulberry molasses group. However, black mulberry molasses usage was an only independent and significant factor in prevention of mucositis [HR 0.63 (%95 GI 0.40-0.98)]. There were no differences between the quality of life scores of experimental and control groups. Conclusions: This randomized controlled study showed that black mulberry molasses usage is an effective intervention in the prevention of the radiation-induced mucositis of head and neck cancer patients. However, to confirm these results, further studies are needed.
AtıfScopus39WoS32OpenAlex40
İncele - MakaleYalnız künye2017Scopus SJRQ2Solutions around a regular α singular point of a sequential conformable fractional differential equation
Unal, Emrah; Gokdogan, Ahmet; Celik, Ercan
In this work, firstly, some concepts of conformable fractional calculus in literature are given. Secondly, definitions of α-analytic point, α-ordinary point and regular α singular point are presented. Finally, the fractional power series solutions are given around a regular-singular point, in the case of variable coefficients for homogeneous sequential linear conformable fractional differential equations of order 2α.
AtıfScopus9WoS9İncele - MakaleAçık Erişim2017Scopus SJRQ2The Technological Properties of Oriental Beech (Fagus orientalis Lipsky) Impregnated with Boron Compounds and Natural Materials
Adanur, Hakan; Fidan, Muhammed Said; Yaşar, Şekip Şadiye
Impregnation, drying, and varnishing are performed to increase the usage life of wood material by making it resistant to chemical, physical, and biological agents. The most common wood protection procedures are chemical methods. Therefore, it is essential to develop new impregnation substances that do not harm the environment and human health but are still economically efficient. In this study, oriental beech (Fagus orientalis Lipsky) was impregnated with borax and boric acid in 1%, 3%, and 5% aqueous solutions. Quechua (Caesalpinia spinosa) was also used as a natural impregnation substance. The retention amount of the impregnated samples was examined for the oven-dried density, bending strength, elastic modulus, screw holding strength tests, compression strength parallel to the grain, and Bending strength parallel to the grain. The samples impregnated with borax had higher oven-dried density, bending strength, elasticity modulus in bending, and Bending strength parallel to the grain tests than samples treated with boric acid; however, the screw holding strength tests showed the opposite trend. The screw holding strength was higher in the impregnated samples than in controls. The bending strength, the elasticity modulus in bending, and the Bending strength parallel to the grain were lower in the control samples.
AtıfScopus5WoS5OpenAlex4İncele - MakaleAçık Erişim2017Scopus SJRQ4Synthesis, spectroscopic characterization, X-ray structure and DFT calculations of Ni(II)bis(3,4 dimethoxybenzoate)bis(nicotinamide) dihydrate
Kaya, Elif Çelenk; Kaya, Afşin Ahmet; Demircioǧlu, Zeynep; Büyükgüngör, Orhan
A single crystal of Ni(II)bis(3,4 dimethoxybenzoate)bis(nicotinamide) dihydrate, formulated as C30H34N4NiO12 (I), was characterized in the solid state by infra-red (IR), ultra-violet (UV) and single crystal X-ray diffraction analysis at 296 K as mononuclear with a distorted octahedral stereochemistry. The complex consists of a six-coordinate Nickel atom in a distorted octahedral environment constructed from two N atoms and four O atoms and crystallizes in the monoclinic space group C 2/c with a=27.7680(16) Å, b=8.5748(3) Å, c=17.8018(9) Å, α=90°, β=108.154(4)°, γ=90°, Z=4. The molecular structure and geometry was also optimized using the B3LYP density functional theory method employing the 6-31G(d) basis set. The molecular electrostatic potential (MEP), frontier molecular orbitals (FMO) analysis, nonlinear optical properties (NLO) and natural bond analysis (NBO), Mulliken population analyis, natural population analysis (NPA) and Fukui function analysis were also described.
AtıfScopus9WoS8OpenAlex11İncele - MakaleAçık Erişim2017Scopus SJRQ3Pasting properties of buckwheat, rice and maize flours and textural properties of their gels: Effect of ascorbic acid concentration
Yildiz, Ö.; Toker, O.S.; Yüksel, F.; Cavus, M.; Ceylan, M.M.; Yurt, B.
In the present study, the effect of ascorbic acid addition on the pasting properties of several gluten-free flours, namely buckwheat, maize and rice flours, and textural properties of their gels were also investigated. Pasting curves of control flour and 10 mg/kg ascorbic acid-including flour were found to be very similar to each other. However, higher levels of ascorbic acid significantly influenced the magnitude of all pasting parameters such as peak viscosity, trough viscosity, breakdown viscosity, final viscosity, setback viscosity, peak time and pasting temperature. Regarding textural properties specifying machinability of the doughs, ascorbic acid addition also generally influenced textural characteristics such as hardness, adhesiveness, springiness, cohesiveness, gumminess, chewiness and resilience parameters of the samples. According to the results, the ascorbic acid level to be used with the gluten-free flour should be adjusted carefully with regard to pasting and textural parameters. Ascorbic acid addition level directly affected the quality of the end products, determining consumer preference.
AtıfScopus7WoS4OpenAlex5İncele - MakaleYalnız künye2017Scopus SJRQ3Investigation of the effects of some modification process to the mechanical performance and deformation of the woodwork
Onduran, Aytekin; Yasar, S. Sadiye; Altunok, Mustafa
In this study, wood modification (thermo-processing and impregnation) and outdoor conditions of storage (natural aging) the effects on the mechanical performance of industrial woodwork was investigated. For this purpose, naturally grown in Turkey and the commercial value of high Scots pine (Pinus sylvestris L.) and chestnut (Castanea sativa Mill) wood was used. Experimental examples are specifically woodwork has been applied in actual size. Considering the previously conducted research literature only diagonal L-type samples used, not on the actual size samples of woodwork. In addition, there is no study that the combination of the heat-treatment and impregnation. This reveals the original values of this study. For preparing of samples is used the double tenon-mortise corner joint from constructions method and as glue polyurethane based Desmodur VTKA and Polyvinyl acetate based two-component D4. Diagonal woodwork test samples prepared by Thermo S class (185°C temperature with a thermo-vapor process protections) applying. After application of the heat treatment, the test samples impregnated with a solution of 95 % natural pine cone resin and %5 pine tannin by dip method (2 hours). Then, the untreated samples (control), only heat-treated samples and heat treatment + impregnated samples kept for 1 year with outdoor conditions (aging). At the end of the aging, the samples tested according to the principles stated in TS 2472 and TS 7251 EN 107 standard. As result, the performance of woodwork decreased after aging in untreated and heat treatment pieces, the other side after aging - heat treatment, impregnation materials increased the values. The deformation value of woodwork increased after aging most untreated materials, Heat treatment and heat treatment-impregnated reduced aging effectiveness.
AtıfScopus3WoS3İncele - MakaleYalnız künye2017Scopus SJRQ2Lasting hepatotoxic effects of prenatal mobile phone exposure
Yilmaz, A.; Tumkaya, L.; Akyildiz, K.; Kalkan, Y.; Bodur, A.F.; Sargin, F.; Efe, H.; Uydu, H.A.; Yazici, Z.A.
Objective: In this study, the livers of rats born to mothers exposed to electromagnetic field (EMF) were examined 60 days postpartum for biochemical and histopathological changes. Methods: Pregnant rats were exposed to radiation (900 MHz EMF, 24 h/day for 20 days) using a digital signal generator by placing the device centrally under the cage, which formed the study (EMF) group, while untreated matching rats served as controls. Livers and blood were obtained from litters (seven males and seven females) of both groups 60 days after birth, which were used for biochemical and histopathological analyses. Results: There was a significant increase in the levels of malondialdehyde (MDA) (p <0.05) that was accompanied by a significant fall in glutathione (GSH) (p <0.01) in the liver. The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly increased (p <0.05). Histopathologically, the liver sections of the EMF group showed intense degeneration in hepatocytes with cytoplasmic eosinophilic structures, pyknotic nuclei and fibrosis. Conclusion: We demonstrate that the intrauterin harmful effects of EMF on the livers of rats persist into adulthood.
AtıfScopus16WoS14OpenAlex19İncele - MakaleAçık Erişim2017Scopus SJRQ1Deterministic stability and random behavior of a Hepatitis C model
Merdan, Mehmet; Bekiryazici, Zafer; Kesemen, Tulay; Khaniyev, Tahir
The deterministic stability of a model of Hepatitis C which includes a term defining the effect of immune system is studied on both local and global scales. Random effect is added to the model to investigate the random behavior of the model. The numerical characteristics such as the expectation, variance and confidence interval are calculated for random effects with two different distributions from the results of numerical simulations. In addition, the compliance of the random behavior of the model and the deterministic stability results is examined.
AtıfScopus10WoS10OpenAlex13İncele - MakaleAçık Erişim2017Scopus SJRQ3Effects of fine aggregate abrasion resistance and its fineness module on wear resistance of Portland cement concrete pavements
Karpuz, Orhan; Akpinar, Muhammet Vefa; Aydin, Metin Mutlu
In this research, effects of fine aggregate abrasion resistance and its fineness module on wear resistance of Portland cement concrete pavements studied. Concrete samples included fine crushed limestone aggregate, fine crushed limestone-basalt mixture, and fine crushed basalt aggregate. The study results showed that LA abrasion rate of 30 % or less of fine aggregates would be necessary for long lasting concrete roads. Furthermore, it was found that fine aggregate's fineness module of 3.15 will significantly increase concrete road surface's wear resistance. As the fine aggregate's fineness module value increased from 2.2 to 3.15, the concrete's wear amount decreased to 15.5 %. Study findings also showed that using basalt aggregates instead of widely used limestone aggregates, will significantly increase pavement concrete wear resistance.
AtıfScopus8WoS4OpenAlex6İncele - MakaleYalnız künye2017Scopus SJRQ2The Stranger to Time: What a Collector Stands for in a Hurried Society
Demir, Sertaç Timur
City-dwellers who are threatened by the risk of natural or social disasters are in search of safer houses. Each attempt to satisfy their need for safety, however, turns into another version of the security problem; so much so that, escaping from risk itself turns into different (yet nevertheless more powerful) risks. The film 10 to 11 (2009) focuses on the socio-spatial conflict between a stranger and his neighbours who are anxious about a possible earthquake risk in Istanbul. Mithat, the protagonist of the film, is a stranger not only to place but essentially to time. He lives within time and understands place as an essential means loaded by temporal experiences and memories. This paper deals with the multiple dichotomies between time and memory, between risk and fear, between aesthetics and security, and between attachment and profit in the context of urban transformation. The stranger, who is analysed for the first time as a temporal being in this paper, is discussed using Zygmunt Bauman’s concepts of uncertainty and liquid modernity, Richard Sennett’s capitalism, Ulrich Beck’s risk society, Frank Furedi’s culture of fear, Stephen Bertman’s hurried culture, Elias Canetti’s death, Giorgio Agamben’s forgotten and gone, Svetlana Boym’s nostalgia, and Halbwachs, Assmann, Connerton, and Arendt’s memory, as well as around the temporal spaces of museums, bibliopoles, antique shops, and cemeteries.
AtıfWoS1OpenAlex2İncele - MakaleYalnız künye2017Scopus SJRQ4Continuity of superposition operators on the double sequence spaces of maddox L(p)
Güngör, Nihan; Sağır, Birsen
Petranuarat and Kemprasit (Southeast Asian Bull Math 21:139–147, 1997) characterized continuity of the superposition operator acting from the sequence space lp into lq where 1 ≤ p, q < ∞. Sağır and Güngör defined the superposition operator Pg by Pg(x) = (g(k, s, xks))∞k,s=1 for all real double sequences (xks) where g: N2 × R → R and gave continuity of the superposition operator acting from the double sequence spaces Lp into Lq for 1 ≤ p, q < ∞. In this paper, we characterize the continuity of the superposition operator acting from Maddox double sequence spaces L(p) into L(q)where p = (pks) and q = (qks) are bounded double sequences of positive numbers.
AtıfScopus1WoS1OpenAlex2İncele - MakaleAçık Erişim2017Scopus SJRQ1Novel eugenol derivatives: Potent acetylcholinesterase and carbonic anhydrase inhibitors
Topal, Fevzi; Gulcin, Ilhami; Dastan, Arif; Guney, Murat
Eugenol was used as starting material to obtain some phenolic compounds. The synthesis of these phenolic compounds was performed in a two-step procedure. The structures of the formed products (novel eugenol derivatives 1–6) have been determined on the basis of NMR spectroscopy and other spectroscopic methods. The compounds were tested in terms of carbonic anhydrase (CA) inhibition potency. Carbonic anhydrases (CAs, EC 4.2.1.1) are metalloenzymes, which catalyse the reaction between carbon dioxide (CO2) and water (H2O), to generate bicarbonate (HCO3−) and protons (H+). CO2, HCO3− and H+ are essential molecules and ions for many important physiologic processes occurring in all living organisms. Acetylcholinesterase (AChE, E.C.3.1.1.7) is found in high concentrations in the red blood cells and brain. Novel eugenol derivatives (1–6) were tested for the inhibition of two cytosolic CA isoforms I, and II (hCA I, and II) and AChE. These compounds demonstrated effective inhibitory profiles with Ki values in ranging of 113.48-738.69 nM against hCA I, 92.35-530.81 nM against hCA II, and 90.10-379.57 nM against AChE, respectively. On the other hand, acetazolamide clinically used as CA inhibitor, shoed Ki value of 594.11 nM against hCA I, and 120.68 nM against hCA II, respectively. Also, AChE was inhibited by tacrine as an AChE inhibitor at the 71.18 nM level.
AtıfScopus126WoS121OpenAlex133İncele - MakaleAçık Erişim2017Scopus SJRQ1Diversity and genetic analysis through DArTseq in common bean (Phaseolus vulgaris L.) germplasm from Turkey
Nemlı, Seda; Kaygisiz Aşçioğul, Tansel; Ateş, Duygu; Eşıyok, Dursun; Tanyolaç, Muhammed Bahattin
The common bean (Phaseolus vulgaris L.) is the most consumed food legume in the world and is a major source of dietary protein, carbohydrates, and valuable micronutrients, especially in developing countries. Diversity Arrays Technology (DArTseq), based on genome reduction with restriction enzymes, provides a rapid, high-throughput, and cost-effective tool capable of generating thousands of genotyped single nucleotide polymorphisms (SNPs) for a genome-wide analysis of genetic diversity. In this study, we aimed to characterize common bean accessions using SNPs detected by a DArTseq approach. A total of 43,018 SNPs were identified from 173 common bean accessions, including Andean and Mesoamerican genotypes. After filtering raw and redundant data, a total of 16,366 SNPs were considered for further analyses. According to population structure analysis, the genotypes were roughly divided into 2 gene pools of Andean and Mesoamerican types. Pairwise fixation index (Fst) values were calculated to resolve the differentiation between populations. This study demonstrated that discovering SNPs from the whole genome is a potential resource for identifying naturally diverse accessions and also the information could be used in breeding programs to develop new common bean varieties.
AtıfScopus19WoS18OpenAlex24TR Dizin3
İncele - MakaleYalnız künye2017Scopus SJRQ1Zircon Lu-Hf isotope systematics and U–Pb geochronology, whole-rock Sr-Nd isotopes and geochemistry of the early Jurassic Gokcedere pluton, Sakarya Zone-NE Turkey: a magmatic response to roll-back of the Paleo-Tethyan oceanic lithosphere
Karsli, Orhan; Dokuz, Abdurrahman; Kandemir, Raif
The early Mesozoic was a critical era for the geodynamic evolution of the Sakarya Zone as transition from accretion to collision events in the region. However, its complex evolutionary history is still debated. To address this issue, we present new in situ zircon U–Pb ages and Lu-Hf isotope data, whole-rock Sr-Nd isotopes, and mineral chemistry and geochemistry data of plutonic rocks to better understand the magmatic processes. The Gokcedere pluton is mainly composed of gabbro and gabbroic diorite. LA-ICP-MS zircon U–Pb dating reveals that the pluton was emplaced in the early Jurassic (177 Ma). These gabbros and gabbroic diorites are characterized by relatively low SiO2 content of 47.09 to 57.15 wt% and high Mg# values varying from 46 to 75. The samples belong to the calc-alkaline series and exhibit a metaluminous I-type character. Moreover, they are slightly enriched in large ion lithophile elements (Rb, Ba, Th and K) and light rare earth elements and depleted in high field strength elements (Nb and Ti). Gabbroic rocks of the pluton have a depleted Sr-Nd isotopic composition, including low initial 87Sr/86Sr ranging from 0.705124 to 0.705599, relatively high εNd (t) values varying from 0.1 to 3.5 and single-stage Nd model ages (TDM1 = 0.65–0.95 Ga). In situ zircon analyses show that the rocks have variable and positive εHf (t) values (4.6 to 13.5) and single-stage Hf model ages (TDM1 = 0.30 to 0.65 Ga). Both the geochemical signature and Sr-Nd-Hf isotopic composition of the gabbroic rocks reveal that the magma of the studied rocks was formed by the partial melting of a depleted mantle wedge metasomatized by slab-derived fluids. The influence of slab fluids is mirrored by their trace-element characteristics. Trace-element modeling suggests that the primary magma was generated by a low and variable degree of partial melting (~5–15%) of a depleted and young lithospheric mantle wedge consisting of phlogopite- and spinel-bearing lherzolite. Heat to melt the mantle material was supplied by the ascendance of a hot asthenosphere triggered by the roll-back of the Paleo-Tethyan oceanic lithosphere. The rising melts were accompanied by fractional crystallization and encountered no or minor crustal contamination en route to the surface. Taking into account these geochemical data and integrating them with regional geological evidence, we propose a slab roll-back model; this model suggests that the Gokcedere gabbroic pluton originated in a back-arc extensional environment associated with the southward subduction of the Paleo-Tethyan oceanic lithosphere during the early Jurassic period. Such an extensional event led to the opening of the northern branch of the Neotethys as a back-arc basin. Consequently, we conclude that the gabbroic pluton was related to intensive extensional tectonic events, which peaked during the early Jurassic in response to the roll-back of Paleo-Tethyan oceanic slab in the final stage of oceanic closure.
AtıfScopus68WoS64OpenAlex68İncele - MakaleYalnız künye2017Scopus SJRQ1System identification of arch dam model strengthened with CFRP composite materials
Altunisik, A.C.; Gunaydin, M.; Sevim, B.; Adanur, S.
This paper presents the structural identification of an arch dam model for the damaged, repaired and strengthened conditions under different water levels. For this aim, an arch dam-reservoir-foundation model has been constructed. Ambient vibration tests have been performed on the damaged, repaired and strengthened dam models for the empty reservoir (0 cm), 10 cm, 20 cm, 30 cm, 40 cm, 50 cm and full reservoir (60 cm) water levels to illustrate the effects of water levels on the dynamics characteristics. Enhanced Frequency Domain Decomposition Method in the frequency domain has been used to extract the dynamic characteristics. The dynamic characteristics obtained from the damaged, repaired and strengthened dam models show that the natural frequencies and damping ratios are considerably affected from the varying water level. The maximum differences between the frequencies for the empty and full reservoir are obtained as 16%, 33%, and 25% for damaged, repaired and strengthened model respectively. Mode shapes obtained from the all models are not affected by the increasing water level. Also, after the repairing and strengthening implementations, the natural frequencies of the arch dam model increase significantly. After strengthening, between 46-92% and 43-62% recovery in the frequencies are calculated for empty and full reservoir respectively. Apparently, after strengthening implementation, the mode shapes obtained are more acceptable and distinctive compared to those for the damaged model.
AtıfScopus11WoS10OpenAlex4İncele