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Koleksiyondaki öğeler
- BildiriYayıncıda açık erişim2018An investigation of the near-wake flow structure of a cylinder with guiding plates
Ekinci, Firat; Firat, Erhan; Özkan, Göktürk M.; Akilli, Hüseyin
In this study, the flow behind a circular cylinder with a pair of outer identical guiding plates was investigated using particle image velocimetry (PIV) for various angular positions of the plates (i.e. α=±70°, ±100°, and ±130°). The gaps between these plates and cylinder are equal and are 0.3D. Experiments were carried out at a subcritical Reynolds (Re=ρ·U∞·D/μ) number of 7500, based on the cylinder diameter (D) and the flow velocity (U∞). The features of the near-wake with and without the guiding plates were interpreted in terms of patterns of time-averaged vorticity and streamlines, time-averaged and fluctuating velocity components. The spectral analysis was also carried out to determine the time-dependent variation of the transverse velocity at given locations in the near-wake. Two-dimensional computations of flow around circular cylinders with and without guiding plates have also been performed to predict the timeaveraged and root-mean-square of force coefficients of the various models. It was seen that the guiding plates at an appropriate angular position can lead to substantial attenuation, or retardation, of the process of large-scale vortex formation in the near-wake, thus can lead to vortex-induced vibration (VIV) suppression without any increase in drag.
- MakaleAçık Erişim2019Scopus SJRQ1Identification of optimum working conditions in hydroelectric power plants for cavitation
Kahraman, Gökhan; Yücel, Halit Lütfi; Taşgin, Yahya
Turbine faults in hydroelectric power plants not only reduce the operation time of the plant, but also cause a serious loss of income. One of the most important turbine faults is the turbine wheel wear caused by the cavitation and accordingly the other machine equipment faults which cause excessive vibration. In this study, cavitation intensity that the turbines have been exposed in operating conditions has been investigated. As a result of the calculations, optimum working conditions of the units have been determined with graphs obtained in various operating conditions. The obtained data can be easily applied to all hydroelectric power plants exposed to cavitation, and safe operating conditions can be determined.
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İncele - Derleme MakaleAçık Erişim2021Scopus SJRQ2Hospital location selection: A systematic literature review on methodologies and applications
Gul, Muhammet; Guneri, Ali Fuat
The increased focus of people on the quality of health care in recent years has led hospital owners to develop strategies and policies to improve medical services through the establishment of new hospitals. For hospitals to be competitive, the hospital's location and proximity to potential patients are considered crucial factors in establishing new hospitals. In this context, evaluating and selecting the most suitable hospital location to establish a new hospital from the multicriteria decision-making (MCDM) perspective is a priority for the entrepreneurs or government to gain a competitive advantage. Therefore, this study aims to present a systematic literature review of the hospital location selection problem considering the applied methods and application areas. The preferred reporting items for systematic review and meta-analysis statement (PRISMA) are used as a reference framework. Initially, known electronic databases (Web of science, IEEEXplore, Scopus, Science direct, and Google Scholar) were searched up to the early 2021. A number of 47 articles are selected and analyzed under this systematic framework based on inclusion-exclusion points. State-of-the-art developments in adopting MCDM methods and their fuzzy extensions are summarized. All the articles have been examined in a systematic taxonomy to find answers to six research questions (trend, country of origin, outlet journal, MCDM methods used, MCDM environment and criteria type, and decision criteria used). Results show that (1) AHP and GISbased MCDM models are the most contributing approaches to the solution of this problem, (2) location selection criteria are mostly cost, demand, environment, population, government, competition in the market, and distance to some important places, (3) the fuzzy structure is also preferred in addition to the MCDM structure depending on the crisp data type, and (4) the location selection criteria are mostly considered subjective. We pay attention to promising directions that can dominate future research in this field from a methodological or applicability perspective. This study shows the current views and opportunities for researchers and practitioners and acts as a guide to encourage more creative studies in this field.
AtıfScopus58WoS43OpenAlex71İncele - MakaleYalnız künye2020Scopus SJRQ2Empirical modeling between degree days and optimum insulation thickness for external wall
Kallioğlu, Mehmet Ali; Ercan, Umut; Avcı, Ali Serkan; Fidan, Cihad; Karakaya, Hakan
Insulating is the most effective method that is used to save energy in buildings. Samples from cities from different climatic zones from TS 825 (Turkey) first. Optimum insulation thickness (xopt) analysis is based on two types of insulating and four different fuels (natural gas, coal, fuel oil and electric) of related cities. Cost accounts, payback period and CO2-SO2 emission calculations were performed based on these analyses. Second of all, the relationship between a number of degree day (NDD) and optimum insulation thickness (xopt) was developed by linear, quadratic and cubic correlations. Thirty different mathematical correlations based on different fuel types by using XPS and EPS insulating materials. Twenty-four of these models that were developed were generated peculiar to the fuel type; six of them were generated based on average insulation thickness. R2 values of related correlations are between 0.9989 most and 0.9952 at least as well as it is pretty close to (R ≤ 1) one value. The model among these models is the xopt xopt = a+b (NDD) + c(NDD)2+ d(NDD)3 cubic mathematical model that gives the best average value. a = 0.0036, b = 5E-05, c =–7E-09 and d = 6E-13 are the values for XPS material. Following values are for EPS material; a = 0.0028, b = 5E-13, c =–7E-09 and d = 4E-05. R2 determination coefficient of both two equations is pretty close to 0.9989 and 1; the models obtained are less-than-stellar. Optimum insulation thickness of the area can be known based on the type of material via the number of degree day without the need for long analyses. According to the R2 values, the use of all models is recommended for academic and industrial users.
AtıfScopus21WoS24OpenAlex22İncele - MakaleAçık Erişim2019Scopus SJRQ3Reassessment of Turkey’s objections to the exclusion of terrorism from the rome statute; [Terörizmin uluslararası ceza divanının yargı yetkisi dışında bırakılmış olmasına dair türkiyeʼnin İtirazlarının yeniden değerlendirilmesi]
Kurtuluş, Şehmus
Criminal justice response to terrorism and to the support for terrorism is still a hot topic in Turkey due to ongoing American military support for the PYD, which is Syrian wing of the internationally designated terrorist organization PKK whose indiscriminate attacks in Turkey has claimed lives of thousands of civilians. This article first discusses, in light of recent developments, whether exclusion of a separate crime of terrorism from the Rome Statute of the International Criminal Court can be a valid argument against Turkey’s accession to it. After discovering some of the possible contributions of Turkey’s Rome Statute accession to its decades-long struggle against terrorism, this study concludes that Turkey’s all other concerns regarding the accession should be periodically reevaluated.
AtıfScopus3WoS4OpenAlex2İncele - BildiriAçık Erişim2020Speed Control of DC Motor Using Single Phase Matrix Converter
Boydak, Merve; Orhan, Ahmet; Caliskan, Abuzer
This paper focuses on speed control of DC motor using new driver circuit of Single-Phase Matrix Converter (SPMC). Changing of modulation index has been provided with closed loop PI control. Thus, the voltage applied to the armature has been controlled and rotating of motor at the desired speed has been enabled. Insulated Gate Bipolar Transistors (IGBTs) are used to perform SPMC topology. Sinusoidal Pulse Width Modulation (SPWM) technique is used to obtain switching signals. MATLAB / Simulink is used to implement simulation.
AtıfScopus3WoS3OpenAlex3İncele - MakaleYalnız künye2019Scopus SJRQ2An ethnobotanical survey of medicinal plants in karlıova (Bingöl-turkey)
Nadiroğlu, Muharrem; Behçet, Lütfi; Çakılcıoğlu, Uğur
This study aims to identify wild plants collected for medical purposes by the local people of Karlıova District located in the Eastern Anatolia region of Turkey and to determine the uses and local names of these plants. A field study had been carried out for a period of approximately 4 years (2013–2016). During this period, 99 vascular plant specimens were collected. Among them, 91 species are wild and 8 species are cultivated plants. Demographic characteristics of participants, names of the local plants, their utilized parts and preparation methods were investigated and recorded. 99 plants were found to be used for medical purposes before in the literature analysis of the plants used in our study, while 9 plants were found to have no literature records. In Turkey, local plant names display differences especially due to local dialects. The plants used in Karlıova are known by the same or different local names in various parts of Anatolia. In the research area, local people were found to use 99 plants from 26 families for curative purposes. The medicinal uses of Stenotaenia macrocarpa Freyn & Sint., Inula helenium L., Scorzonera incisa DC., Tripleurospermum caucasicum (Willd.) Hayek, Astragalus chamaephaca Freyn, Geranium libanoticum Schenk, Rhinanthus serotinus subsp. aestivalis (N.W.Zinger) Dostál, Verbascum songaricum Schrenk. and Bunium elegans (Fenzl) Freyn that we found were used in our study area and recorded for the first time. These plants, used for the treatment of various diseases, are abundantly found in this region. Drying of the medicinal plants enabled the local people to use them in every season of the year.
AtıfScopus45İncele - MakaleAçık Erişim2019Scopus SJRQ2Microborings as indication of cryptic life modes in the foraminifer Orbitoides: Maastrichtian sediments of the Haymana and Nallihan districts (Ankara, Turkey)
Görmüş, Muhittin; Demırcan, Huriye; Kadioğlu, Yusuf Kağan; Yağmurlu, Fuzuli; Us, Muhammed Sami
Widespread Maastrichtian siliciclastics and carbonates cropping out in the Haymana (S Ankara) and Nallihan (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 Görmüs, Maeandropolydora isp. Curvichnus semorbis Nielsen, Oichnus simplex Bromley, Oichnus isp. Maeandropolydora osmaneliensis Nielsen and Görmüs. Maeandropolydora isp., semicircular to circular microborings of Curvichnus semorbis Nielsen and Oichnus simplex Bromley are related to parasitic life modes. Irregular wider unidentified microborings are hermit type life mode tunnels. Abundance of the microborings might be related to shallower siliciclastic environmental conditions such as feeding and suitable Eh-pH, test shape, and easy entrance to the test for parasites. Smaller benthic foraminifera are seen in both microspheric and megalospheric Orbitoides tests as parasites. In conclusion, occurrences of microborings and encrustations are associated with parasitism by appearances of Maeandropolydora osmaneliensis Nielsen and Görmüs, Curvichnus semorbis Nielsen and Oichnus simplex Bromley and commensally attachment by microalgae.
AtıfScopus10OpenAlex8İncele - MakaleYalnız künye2018Scopus SJRQ2Fuzzy rule-based Fine–Kinney risk assessment approach for rail transportation systems
Gul, Muhammet; Celik, Erkan
Rail transportation is one of the most crucial public transportation types for big and crowded cities. In rail transportation systems, stakeholders face serious issues involved in workshops, stations, lines and their environments, and general office buildings. In order to reach an increased awareness and better occupational health and safety (OHS) management, a new risk assessment approach is proposed in this study. This approach includes a combination of Fine–Kinney method and a fuzzy rule-based expert system. It captures nonlinear causal relationships between Fine–Kinney parameters. Since there is a high level of vagueness involved in the OHS risk assessment data, the rule-based expert system is developed for probability (P), exposure (E), and consequence (C) for evaluating risk score. A case study is carried out in a rail transportation system in Istanbul/Turkey, and a comparison with the classical Fine–Kinney method is discussed. Results of the case study reveal risk clusters and corresponding control measures that should be taken into consideration. The study methodologically contributes to risk assessment in the knowledge, while case study in a real rail transportation system offers an insight into public transport industry in safety improvement.
AtıfScopus81WoS71OpenAlex86İncele - MakaleYalnız künye2019Scopus SJRQ2Gamma ray shielding behavior of Li2O-doped PbO–MoO3–B2O3 glass system
Ali, Atif Mossad; Sayyed, M.I.; Rashad, M.; Kumar, Ashok; Kaur, Ramandeep; Aşkın, A.; Algarni, H.
In this work, five glasses for radiation shielding applications in the composition of (30 + x) PbO–5 MoO3–(25 − x) Li2O–40 B2O3 (where x = 0, 5, 10, 15 and 20 mol%) have been prepared. The density increases from 4.354 to 6.578 g cm−3 and the molar volume decreases from 25.144 to 22.520 cm3 with the replacement of Li2O by PbO. The indirect and direct band gap energies decrease from (2.2870–2.2297) eV and (2.9619–2.8660) eV, respectively, as lead content increases from 30 to 50 mol%. In addition, the refractive index of the samples lies between 2.6214 and 2.6429. Geant4 simulation code has been used to evaluate the gamma photon transmission through the prepared samples. Pb50Li5 sample has lower transmission fraction among the studied glasses. For the 2-cm glass thickness, the transmission fraction of Pb30Li25 sample was found to be 0.433 while at the same thickness the transmission fraction of Pb50Li5 sample is 0.265. At 1173 keV, the HVL values were found to be 1.752 cm for Pb50Li5 and 2.693 cm for Pb30Li25 glasses. At the same photon energy, the MFP values were calculated to be 2.529 cm and 3.886 cm for the Pb50Li5 and Pb30Li25 samples, respectively. Due to the higher Pb content existing in the Pb50Li5 glass, this glass effectively blocks the gamma rays compared to the other samples.
AtıfScopus21OpenAlex24İncele - MakaleYalnız künye2018Scopus SJRQ1Antioxidant biomarkers in Gammarus pulex to evaluate the efficiency of electrocoagulation process in landfill leachate treatment
Serdar, Osman; Yildirim, Nuran Cikcikoglu; Tatar, Sule; Yildirim, Numan; Ogedey, Aysenur
The discharge of landfill leachate into the environment without effective treatment poses a serious threat for the aquatic ecosystems. This present study was undertaken to evaluate whether electrocoagulation process is efficient for treatment landfill leachate (LL) or not by using antioxidant biomarkers in Gammarus pulex. Glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT) activities and malondialdehyde (MDA) and glutathione (GSH) levels in G. pulex exposed to untreated, treated, and diluted rates 1/10 and 1/20 in both LL during 24 and 96 h were tested. Physiochemical characteristics of leachate (chemical oxygen demand, electrical conductivity, pH, phosphate, turbidity, NH3, Cl−, and color) were determined pre and post treatment. All physiochemical characteristics of LL decreased after treatment process. GSH-Px and CAT activities and GSH and MDA levels were increased in untreated groups when compared to control (p < 0.05). After treatment by electrocoagulation, MDA and GSH levels and CAT activities were returned to control values. In conclusion, the abilities of LL to stimulate oxidative stress in G. pulex have been proven. The results revealed that antioxidant parameters are useful biomarkers for determining the treatment efficiency of the electrocoagulation process.
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İncele - MakaleYalnız künye2018Scopus SJRQ2Phenotypic differentiation analysis: A case study in hybridizing Çoruh trout (Salmo coruhensis), Rize trout (Salmo rizeensis) and brown trout (Salmo trutta fario)
Kocabaş, Mehmet; Kutluyer, Filiz; Başçinar, Nadir
The aim of this study was to determine and compare the phenotypic variation in Çoruh trout (Salmo coruhensis), Rize trout (Salmo rizeensis), brown trout (Salmo trutta fario) and their native hybrids (S. rizeensis × S. t. fario; S. t. fario × S. coruhensis; S. rizeensis × S. coruhensis). The numbers and diameters of red and black spots were determined on operculum, fins and above and below the lateral line. The results from this study indicate that there were differences in spotting pattern, colour pattern or fin pigmentation traits between S. rizeensis, S. t. fario, S. coruhensis and their hybrids. Consequently, native S. rizeensis, S. t. fario and S. coruhensis were affected by interaction and phenotypic plastic aspects of traits in S. rizeensis were dominant in their hybrids (S. rizeensis × S. t. fario; S. rizeensis × S. coruhensis).
AtıfScopus2WoS1OpenAlex3İncele - BildiriYalnız künye2018Quality lignite coal detection with discrete wavelet transform, discrete fourier transform, and ANN based on k-means clustering method
Korkmaz, Sevcan Aytac; Esmeray, Furkan
In this article, the lignite coal datas in the Kalburcayi area of the Sivas-Kangal Basin have been used. This original data obtained from Kalburcayi area of the Sivas-Kangal Basin consists of 66 observations in the lignite coal area, including lignite quality parameters such as moisture content, ash, sulfur content and calorific value. These lignite coal datas have been clustered in two group with k-means method according to calori values. This clustering lignite coal data is classified by the Artifical Neural Network (ANN) classifier. In addition, Discrete Fourier Transform (DFT) and Discrete Wavelet Transform (DWT) have been applied to coal data for ANN classifiers. DFT-ANN, DWT-ANN, and ANN classification success results are compared. The highest classification success rate was found by DWT-ANN method.
AtıfScopus8OpenAlex12İncele - MakaleYalnız künye2019Scopus SJRQ2The usability of oxidative stress and detoxification biomarkers in Gammarus pulex for ecological risk assessment of textile dye methyl orange
Cikcikoglu Yildirim, Nuran; Yaman, Metin
The present study was undertaken to determine the toxicity of the methyl orange by using the changes of some antioxidant and detoxification enzyme activities in Gammarus pulex. Lethal Concentration (LC) value of Methyl Orange (MO) was determined. Three sublethal doses of MO (1/4; 1/8 and 1/16 of LC value) were exposed to G. pulex for 24 and 96 h. Superoxide dismutase (SOD), Catalase (CAT), Glutathione peroxidase (GSH-P X ), Cytochrome p450 (CYP1A1), Glutathione S-transferase (GST) activities as well as Glutathione (GSH) and Malondialdehyde (MDA) levels were determined by using The enzyme-linked immunosorbent assay (ELISA) kit. The CAT and CYP1A1 activities were decreased in all the groups exposed to different doses of MO. GST activity and GSH, MDA levels were increased all the groups exposed to different doses of MO. The GSH-P X activities were changed in all the groups. MO affected SOD activity at different levels and in different concentrations. In our study, it has been found that exposure duration didn’t significantly affect the biochemical biomarkers except for GST and GSH. In conclusion, alterations in antioxidant and detoxification enzymes and lipid peroxidation may potentially be used as sensitive biomarkers for risk assessment of dyes in the environment and may contribute to the establishment of discharge regulations.
AtıfScopus17WoS18OpenAlex18İncele - MakaleYalnız künye2019Scopus SJRQ2Effects of Vacuum Ohmic Evaporation on Some Quality Properties of Sour Cherry Juice Concentrates
Sabancı, Serdal; Icier, Filiz
Sour cherry juice (SJ) having total soluble solid (TSS) content of 19.2 % was concentrated to 65 % TSS by applying vacuum ohmic evaporation (VOE) and vacuum evaporation (VE) methods under constant absolute pressure (25 kPa). Total monomeric anthocyanin content (TMAC) of sour cherry concentrate (65 % TSS) was found in the range of 1561.67–1777.38 mg/L whereas total phenolic content (TPC) varied in the range of 9,071.22–78,347.53 mg/L concentrate. TPC and TMAC values of juice concentrates were affected less from VOE process compared to VE (p < 0.05) while there was no significant difference between the total antioxidant activities of SJ concentrates obtained by both methods (p > 0.05). TMAC and TPC values increased as the voltage gradient applied increased (p < 0.05). VOE process preserved the color properties of juice concentrates better compared to the VE process. It was concluded that VOE method could be an alternative fast evaporation method to obtain high-quality fruit juice concentrates.
AtıfScopus35WoS31OpenAlex34İncele - MakaleAçık Erişim2020Scopus SJRQ3Modeling of Drying Processes of Dates (Phoenix, Arecaceae) with Oven or TGA and Microbiological Properties of Fresh and Dried Dates
Ertekin, Özlem; İpek, Yeliz
Drying method, which is one of the oldest preservation methods, is important for preserving fruits. Date palm fruit is an important food in human nutrition due to some vitamins, minerals, sugar, phenolic components, and high fiber content. In the literature, date palm drying was not studied sufficiently in the aspect of mathematical modeling and the effect of drying process on the microbiological properties. In this novel study, date palm drying process was applied with four different temperatures of 50°C, 70°C, 90°C, and 110°C with two different drying techniques; drying with oven and drying with thermogravimetric analysis (TGA). Chemical changes in the date palm structure after drying at different temperatures were investigated with FTIR analysis. Fibrous structure of palm fruit is also exhibited with SEM analysis. On the other hand, microbiological studies were applied both for fresh and dried date palm to observe the drying process effect on the growth of different types of microorganisms. Consequently, drying time decreased with increasing drying temperature while the color of the dried date palm fruit became darker with increasing temperature. However, the chemical structure was not affected. Drying time of oven drying technique was longer than drying with TGA technique. The mathematical model of the drying temperature depending on drying time is calculated as (Formula presented.) for TG-DTA drying experiments and (Formula presented.) for drying process with oven. In addition, the microbiological load has significantly decreased or disappeared with the drying process.
AtıfScopus6WoS6OpenAlex6İncele - MakaleYalnız künye2019Scopus SJRQ3Physicochemical and sensory evaluation of fish chips made from Luciobarbus esocinus (Heckel, 1843)
Kuzgun, N.K.
In this study, fish chips were produced using Luciobarbus esocinus, their fatty acids and amino acids profiles were determined and they were sensorially evaluated. For the preparation of experimental samples, L. esocinus meat was minced and added to a basic chips mixture. After that, the mixture was divided into in two: while pepper sauce was added to one half, the other half had no sauce added. The mixtures with sauce and without sauce were shaped into chips. Two samples of each batch of the chips prepared were cooked using two different methods (baking and frying). In this way four different groups were obtained. Analysis of fatty acids showed that the pre-frying and the pre-baking process resulted in a decrease in all fatty acids except for 18:1n-9 and 18:2n-6. Analysis of amino acids showed that isoleucine, lysine, threonine and, proline were present in the highest quantities respectively. After frying and baking the amounts of leucine, isoleucine, lysine, arginine, phenylalanine, and threonine decreased while the amounts of the valine and histidine remained at the same level. The essential amino acids for humans were found in the fish meat and in the fish chip groups, except for tryptophan. The general acceptability score of the fish chips was highest for group A which consisted of chips with sauce that had been fried (9.28±0.69).
- MakaleAçık Erişim2018Scopus SJRQ3Location and coverage analysis of bike-sharing stations in university campus
Mete, Suleyman; Cil, Zeynel Abidin; Özceylan, Eren
Background: Bike-sharing programmes have become popular in a large number of cities in order to facilitate bicycle use. Determining the location of bike sharing stations is vital to success of these programmes. Objectives: In this paper, a case study is applied to the Gaziantep University campus in order to find possible locations of the stations for users (students). The purpose is to minimize the total walking distance. Methods/Approach: Set and maximal covering mathematical models are considered to decide on coverage capability of determined 20 demand points and 20 potential bike stations. Then, the mathematical models of P-center and P-median are used to build possible stations and to allocate demand points to the opened stations. Finally, an undesirable facility location model is used to find the bike stations, which have the maximum distance from demand nodes, and to eliminate them. Results: In computational results, it is clearly seen that the proposed approaches set the potential bike station covering all demand points. They also provide different solutions for the campus planners. Conclusions: The methodology outlined in this study can provide university administrators with a useful insight into locations of stations, and in this way, it contributes significantly to future planning of bike-sharing systems.
AtıfScopus40WoS27OpenAlex38İncele - MakaleAçık Erişim2019Scopus SJRQ1Petrology and 40Ar-39Ar dating of paragneisses from the Devrekani Massif (Central Pontides, Northern Turkey): Implications for the Jurassic high-T metamorphism in an extensional tectonic environment
Gücer, Mehmet Ali; Arslan, Mehmet; Çimen, Okay; Sherlock, Sarah C.
The Devrekani Massif in the northern part of the Central Pontides (Northern Turkey) provides important clues to the regional tectonics and geodynamic processes associated with Jurassic high grade metamorphic conditions. This study reports new paragenetic assemblages, mineral compositions, whole-rock geochemistry and 40Ar-39Ar geochronological data from the paragneisses in the massif, and, discusses the P–T conditions and geodynamic implications of the Jurassic metamorphism during continental extension in the Central Pontides. Upper amphibolite to lower granulite facies paragneisses form one of the main lithological units in the massif. Within these, there are five different mineral parageneses with diagnostic mineral assemblages of: quartz, K-feldspar (An0-1Ab4-26Or73-96), plagioclase (An18-35), biotite [XPhl: 0.28–0.57; Mg/(Mg + Fe2+): 0.33–0.61], sillimanite, cordierite [Mg/(Mg + Fe2+): 0.48–0.71] and garnet (Alm43-80Grs0-18Prp5-23And0-4Sps10-33) with minor hercynite. Based on Na-in-Crd thermometry and GASP barometry results, the peak metamorphic conditions are 775 ± 25 °C and 6 ± 1 kbar in the massif. The field relations, petrography and bulk chemical data suggest that the paragneisses, derived from shale-wackestone and pelitic sedimentary protoliths, are typical rock lithologies of an active continental margin. They display enrichments in LILE over HFSE, coupled with negative Nb and Ti anomalies, which are geochemical signatures of subduction-related sources. It is likely that the peak metamorphism took place during the Middle–Upper Jurassic period (ca. 174–156 Ma), suggesting that the metamorphic rocks cooled to 300–350 °C at ca. 156 Ma. The mineral assemblages reveal that the prograde history passed from sillimanite zone conditions up to the cordierite-garnet-K-feldspar zone. The petrological and geochronological data indicate that the protoliths are related to multiple sources such as volcano-sedimentary successions. We conclude that the Devrekani Massif represents the products of pre-Jurassic sedimentation, and Permo-Carboniferous continental arc magmatism, overprinted by Jurassic metamorphism.
AtıfScopus9OpenAlex6İncele - MakaleYalnız künye2020Scopus SJRQ2Synthesis and modification of amine-terminated maleic anhydride‑butyl acrylate copolymer and investigation of adsorption properties for cadmium (II) ions (Cd2+)
Yilmaz, Ersen; Erenler, Fatih Mehmet; Boztuğ, Ali
In this study, a maleic anhydride‑butyl acrylate copolymer (MA-BA) was synthesized using maleic anhydride (MA) and butyl acrylate (BA) monomers. The synthesis was carried out in methyl ethyl ketone by benzoyl peroxide as the initiator at 70 °C. Secondly, the MA-BA copolymer was chemically modified with ethylenediamine and abbreviated as NH2MA-BA. The copolymer and its modified structure were analyzed spectroscopically by FT-IR, thermally by Thermo Gravimetry (TGA) and by Differential Scanning Calorimetry (DSC). Solubility tests of both structures were performed. Then, the adsorption of cadmium ions (Cd2+) by the modified copolymer (NH2MA-BA) was studied. The copolymer and its modified structure were synthesized successfully, and this was proven by their FTIR spectra. The (MA-BA) copolymer is soluble in common organic solvents but (NH2MA-BA) is not due to cross-linking. The DSC and DTA results showed that chemical modification improved the structure thermally. It was shown that the Freundlich model was the best explanation for the adsorption type in correspondence with the experimental plots, and the modified copolymer is a good candidate for Cd2+ adsorption.
AtıfScopus8WoS7OpenAlex8İncele
